* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Diarrhoeal Diseases – Cholera
Race and health wikipedia , lookup
Special needs dentistry wikipedia , lookup
Medical ethics wikipedia , lookup
Nutrition transition wikipedia , lookup
Diseases of poverty wikipedia , lookup
Transmission (medicine) wikipedia , lookup
Infection control wikipedia , lookup
Malnutrition wikipedia , lookup
Adherence (medicine) wikipedia , lookup
TM3 ➤➤➤➤➤ Diarrhoeal Diseases – Cholera General Objective To provide participants with basic medical knowledge in Diarrhoeal Diseases (DD) and basic principles for preparedness and response to cholera and epidemic diarrhoeal diseases. Specific Objectives At the end of the session, participants will be familiar with: ➠ Clinical manifestations and diagnosis of DD ➠ Treatment options and prevention of DD ➠ Clinical practice in DD ➠ preparedness and detection of cholera ➠ appropriate response ➠ administration of treatment with the implementation of community Content Morbidity and mortality attributable to diarrheal disease in infants and young children can be reduced by a variety of preventive measures and by improved clinical management of those episodes that occur. Recent evidence indicates that the incidence of diarrheal disease can be diminished by decreasing exposure to enteropathogens that frequently are present in foods, and that the severity (purging rate and duration) and frequency of illness can be diminished by improving the host's nutritional status. At the same time about 20% of those who are infected of cholera develop acute, watery diarrhoea (10–20% of these individuals develop severe watery diarrhoea with vomiting). If these patients are not promptly and adequately treated, the loss of such large amounts of fluid and salts can lead to severe dehydration and death within hours. The case-fatality rate in untreated cases may reach 30–50%. Treatment is straightforward (basically rehydration) and, if applied appropriately, should keep casefatality rate below 1%. ➠ Clinical manifestations and Diagnosis of acute diarrhoea ● Clinical evaluation ● Laboratory evaluation ● Prognostic Factors and differential diagnosis ➠ Treatment Options and Prevention ● Rehydration ● Supplemental Zinc Therapy, Multivitamins, and Minerals ● Diet – Non specific antidiarrheal treatment ● Prevention (water, sanitation and hygiene – vaccines) ➠ Clinical Practice in acute diarrhoea (adults, children) ➠ Cholera ● New strategies: oral cholera vaccines ● Case definition - confirmation ● Improved preparedness and treatment (training of health workers, rehydration, intravenous therapy, antibiotics, health education, vaccination, trade and travel restrictions, mass chemoprophylaxis) ● Surveillance of patients with severe cholera Methodology ➠ PPt Presentations ➠ Lecture/discussion format ➠ Case study TM3 / DIARRHOEAL DISEASES References 2 Diarrhoeal Diseases Clinical Manifestations and Diagnosis Despite clinical clues, determining the causative agent of diarrhea in an individual patient on the basis of clinical grounds alone is usually difficult. Episodes of diarrhea can be classified into three categories: Acute diarrhea ● Dysentery ● Bloody diarrhea, visible blood and mucus present Persistent diarrhea ● Episodes of diarrhea lasting more than 14 days Presence of three or more loose, watery stools within 24 hours Table: Linking the Main ● Bloody stools ● ● ● Vomiting ● Common and associated with invasive pathogens Invasive and cytotoxin releasing pathogens Suspect Enterohemorrhagic Escherichia (E.) coli (EHEC) infection in the absence of fecal leukocytes Not with viral agents and enterotoxins releasing bacteria Frequently in viral diarrhea and illness caused by ingestion of bacterial toxins (e.g., Staphylococcus aureus). Symptoms to the Causes of Acute Diarrhea CLINICAL EVALUATION The initial clinical evaluation of the patient (see “Table: Levels of Dehydration in Children with Acute Diarrhea” below) should focus on: ➠ Assessing the severity of the illness and the need for rehydration ➠ Identifying likely causes on the basis of the history and clinical findings TM3 / DIARRHOEAL DISEASES Fever 3 Table: Evaluation of the Acute Diarrhea Patient History ● ● ● ● ● Onset frequency, quantity Chara‘ cter - bile/blood/mucus Vomiting Past medical history, underlying medical conditions Epidemiological clues Physical Examination ● ● ● ● Body weight Temperature Heart & respiratory rate Blood pressure Assess Dehydration ● ● ● ● ● ● ● General appearance, alertness Pulse and blood pressure Postural hypotension Mucous membranes and tears Sunken eyes, skin turgor Capillary refill, jugular venous pressure Sunken fontanelle Table: Levels of Dehydration in Children with Acute Diarrhea No Dehydration ● ● ● ● Alertness normal No sunken eyes Normal drinking Immediate skin pinch Mild Dehydration (≥ 2 signs) ● ● ● ● Restless or irritable Sunken eyes Drinks eagerly Slow skin pinch (<2 sec) Severe Dehydration (> 2 signs) ● ● ● ● Abnormally sleepy or lethargic Sunken eyes Drinking poorly or not at all Very slow skin pinch (>2 sec) Cautionary note: Being lethargic and sleepy are not the same. A lethargic child is not simply asleep: the child’s mental state is dull and the child cannot be fully awakened; the child may appear to be drifting into unconsciousness. In some infants and children, the eyes normally appear somewhat sunken. It is helpful to ask the mother if the child’s eyes are normal or more sunken than usual. The skin pinch is less useful in infants or children with marasmus or kwashiorkor, or obese children. Other signs that may be altered in children with severe malnutrition are described in section 8.1 of the World Health Organization (WHO) 2005 Guideline. TM3 / DIARRHOEAL DISEASES Signs of dehydration in adults 4 ➠ ➠ ➠ ➠ ➠ ➠ Pulse rate >90 Postural hypotension Supine hypotension and absence of palpable pulse Dry tongue Sunken eyeballs Skin pinch Laboratory Evaluation For acute enteritis and colitis, maintaining adequate intravascular volume and correcting fluid and electrolyte disturbances take priority over the identification of the causing agent. Stool cultures are usually unnecessary for immunocompetent patients who present within 24 hours after the onset of acute, watery diarrhea. Microbiologic investigation is indicated in patients who are dehydrated or febrile or have blood or pus in their stool. Epidemiologic clues to infectious diarrhea can be found by evaluating the incubation period, history of recent travel, unusual food or eating circumstances, professional risks, recent use of antimicrobials, institutionalization, and human immunodeficiency virus (HIV) infection risks. Stool analysis and culture costs can be reduced by improving the selection and testing of the specimens submitted on the basis of interpreting the case information — such as patient history, clinical aspects, visual stool inspection, and estimated incubation period. The identification of a pathogenic bacterium, virus, or parasite in a stool specimen from a child with diarrhea does not indicate in all cases that it is the cause of illness. Certain laboratory studies may be important when the underlying diagnosis is unclear or diagnoses other than acute gastroenteritis are possible. Measurement of serum electrolytes is only required in children with severe dehydration or with moderate dehydration and an atypical clinical history or findings. Hypernatremic dehydration requires specific rehydration methods — irritability and a doughy feel to the skin are typical manifestations and should be sought specifically. Prognostic Factors and Differential Diagnosis Table: Prognostic Factors in Children Malnutrition Approximately 10 percent of children in developing countries are severely underweight. ● Macronutrient or micronutrient deficiencies in children are related with more severe and prolonged diarrhea. ● A poor nutritional status causes an elevated risk for diarrheal death. ● Zinc Deficiency ● Suppresses immune system function and is associated with an increased prevalence of persistent diarrhea Persistent Diarrhea Often results in malabsorption and significant weight loss, further promoting the cycle ● Immunosuppression ● Secondary to infection with HIV or other chronic conditions may have an increased risk for the development of clinical illness, prolonged resolution of symptoms, or frequent recurrence of diarrheal episodes ➠ ➠ ➠ ➠ ➠ Meningitis Bacterial sepsis Pneumonia Otitis media Urinary tract infection TM3 / DIARRHOEAL DISEASES Differential diagnosis of acute diarrhea in children 5 Treatment Options and Prevention Rehydration Oral rehydration therapy (ORT) is the administration of fluid by mouth to prevent or correct dehydration that is a consequence of diarrhea. ORT is the standard for efficacious and cost-effective management of acute gastroenteritis, also in developed countries. Oral rehydration salt (ORS) solution is the fluid specifically developed for ORT. A more effective, lower-osmolarity ORS (with reduced concentrations of sodium and glucose, associated with less vomiting, less stool output, and a reduced need for intravenous infusions in comparison with standard ORS) has been developed for global use (see Table 4 in the original guideline document). The hypotonic WHO-ORS is also recommended for use in treating adults and children with cholera. ORT consists of: ➠ Rehydration – water and electrolytes are administered to replace losses ➠ Maintenance fluid therapy (along with appropriate nutrition) In children who are in hemodynamic shock or with abdominal ileus, ORT may be contraindicated. For children who are unable to tolerate ORS via the oral route (with persistent vomiting), nasogastric (NG) feeding can be used to administer ORS. Global ORS coverage rates are still less than 50%, and efforts must be made to improve coverage. Rice-based ORS is superior to standard ORS for adults and children with cholera, and can be used to treat such patients wherever its preparation is convenient. Rice-based ORS is not superior to standard ORS in the treatment of children with acute noncholera diarrhea, especially when food is given shortly after rehydration, as is recommended to prevent malnutrition. TM3 / DIARRHOEAL DISEASES Supplemental Zinc Therapy, Multivitamins, and Minerals 6 For all children with diarrhea: 20 mg zinc for 14 days Zinc deficiency is widespread among children in developing countries. Micronutrient supplementation — supplementation treatment with zinc (20 mg per day until the diarrhea ceases) reduces the duration and severity of diarrheal episodes in children in developing countries. Supplementation with zinc sulfate (2 mg per day for 10 to 14 days) reduces the incidence of diarrhea for 2 to 3 months. It helps reduce mortality rates among children with persistent diarrheal illness. Administration of zinc sulfate supplements to children suffering from persistent diarrhea is recommended by the WHO. All children with persistent diarrhea should receive supplementary multivitamins and minerals each day for 2 weeks. Locally available commercial preparations are often suitable; tablets that can be crushed and given with food are least costly. These should provide as broad a range of vitamins and minerals as possible, including at least two recommended daily allowances (RDAs) of folate, vitamin A, zinc, magnesium, and copper. As a guide, one RDA for a child aged 1 year is: ➠ ➠ ➠ ➠ ➠ Folate: 50 micrograms Zinc: 20 micrograms Vitamin A: 400 micrograms Copper: 1 mg Magnesium: 80 mg Diet The practice of withholding food for >4 hours is inappropriate. Food should be started 4 hours after starting ORT or intravenous fluid. The notes below apply to adults and children unless age is specified. Give: ➠ An age-appropriate diet — regardless of the fluid used for ORT/maintenance ➠ Infants require more frequent breast feedings or bottle feedings — special formulas or dilutions unnecessary ➠ Older children should be given appropriately more fluids ➠ Frequent, small meals throughout the day (six meals/day) ➠ Energy and micronutrient-rich foods (grains, meats, fruits, and vegetables) ➠ Increasing energy intake as tolerated following the diarrheal episode Avoid: ➠ Canned fruit juices – these are hyperosmolar and can aggravate diarrhea. ➠ Probiotics are specific defined live microorganisms, such as Lactobacillus GG (American Type Culture Collection [ATCC] 53103), which have demonstrated health effects in humans. Nonspecific Antidiarrheal Treatment ANTIMOTILITY: L o p e r a m i d e is the agent of choice for adults (4 to 6 mg/day; 2 to 4 mg/day for children >8 years). Should be used mostly for mild to moderate traveler’s diarrhea (without clinical signs of invasive diarrhea). Inhibits intestinal peristalsis and has mild antisecretory properties. Should be avoided in bloody or suspected inflammatory diarrhea (febrile patients). Significant abdominal pain also suggests inflammatory diarrhea (this is a contraindication for loperamide use). Loperamide is not recommended for use in children <2 years. A n t i s e c r e t o r y a g e n t s : Bismuth subsalicylate can alleviate stool output in children or symptoms of diarrhea, nausea, and abdominal pain in traveler’s diarrhea. R a c e c a d o t r i l is an enkephalinase inhibitor (nonopiate) with antisecretory activity, and is now licensed in many countries in the world for use in children. It has been found useful in children with diarrhea, but not in adults with cholera. A d s o r b e n t s : Kaolin-pectin, activated charcoal, attapulgite. Inadequate proof of efficacy in acute adult diarrhea Antimicrobials Antimicrobial therapy is not usually indicated in children. Antimicrobials are reliably helpful only for children with bloody diarrhea (most likely shigellosis), suspected cholera with severe dehydration, TM3 / DIARRHOEAL DISEASES None of these drugs addresses the underlying causes of diarrhea. Antidiarrheals have no practical benefits for children with acute/persistent diarrhea. Antiemetics are usually unnecessary in acute diarrhea management. 7 and serious nonintestinal infections (e.g., pneumonia). Antiprotozoal drugs can be very effective for diarrhea in children, especially for Giardia, Entamoeba histolytica, and now Cryptosporidium, with nitazoxanide. In adults, the clinical benefit should be weighed against the cost, the risk of adverse reactions, harmful eradication of normal intestinal flora, the induction of Shiga toxin production, and the increase of antimicrobial resistance. Antimicrobials are to be considered the drugs of choice for empirical treatment of traveler’s diarrhea and of community-acquired secretory diarrhea when the pathogen is known (see Figure 11 in the original guideline document). Considerations with regard to antimicrobial treatment: ✒ Consider antimicrobial treatment for: ● Persistent Shigella, salmonella, campylobacter, or parasitic infections ● Infections in the aged, immunocompromised patients, and patients with impaired resistance, sepsis, or with prostheses ● Moderate/severe traveler’s diarrhea or diarrhea with fever and/or with bloody stools – quinolones (co-trimoxazole second choice) ✒ Nitazoxanide is an antiprotozoal and may be appropriate for Cryptosporidium and other infections, including some bacteria. ✒ Rifaximin is a broad-spectrum, non-absorbed antimicrobial agent that may be useful. ➠ ➠ ➠ ➠ ➠ ➠ TM3 / DIARRHOEAL DISEASES ➠ 8 ➠ Note well (N.B.): Erythromycin is hardly used for diarrhea today. Azithromycin is widely available and has the convenience of single dosing. For treating most types of common bacterial infection, the recommended azithromycin dosage is 250 mg or 500 mg once daily for 3 to 5 days. Azithromycin dosage for children can range (depending on body weight) from 5 mg to 20 mg per kilogram of body weight per day, once daily for 3 to 5 days. Quinolone-resistant Campylobacter is present in several areas of South-East Asia (e.g., in Thailand) and azithromycin is then the appropriate treatment. Treatment for amoebiasis should, ideally, include diloxanide furoate following the metronidazole, to get rid of the cysts that may remain after the metronidazole treatment. All doses shown are for oral administration. If drugs are not available in liquid form for use in young children, it may be necessary to use tablets and estimate the doses given in this table. Selection of an antimicrobial should be based on the sensitivity patterns of strains of Vibrio (V.) cholerae O1 or O139, or Shigella recently isolated in the area. An antimicrobial is recommended for patients older than 2 years with suspected cholera and severe dehydration. Alternative antimicrobials for treating cholera in children are trimethoprim/sulf amethoxazole (TMP-SMX) (5 mg/kg TMP + 25 mg/kg SMX, b.i.d. [twice a day] for 3 days), furazolidone (1.25 mg/kg, q.i.d. [four times a day ] for 3 days), and norfloxacin. The actual selection of an antimicrobial will depend on the known resistance/sensitivity pattern of V. cholerae in the region, which requires the availability of a well-established and consistent surveillance system. For adults with acute diarrhea, there is good evidence that an ultrashort course (one or two doses) of ciprofloxacin or another fluoroquinolone reduces the severity and shortens the duration of acute traveler’s diarrhea. This area is still controversial; use should be limited to highrisk individuals or those needing to remain well for short visits to a high-risk area. Prevention Water, sanitation, and hygiene: ● Safe water ● Sanitation: houseflies can transfer bacterial pathogens ● Hygiene: hand washing Safe food: ● Cooking eliminates most pathogens from foods ● Exclusive breastfeeding for infants ● Weaning foods are vehicles of enteric infection Micronutrient supplementation: the effectiveness of this depends on the child’s overall immunologic and nutritional state; further research is needed. ➠ ➠ ➠ ➠ ➠ TM3 / DIARRHOEAL DISEASES ➠ Vaccines: Salmonella typhi: Two typhoid vaccines currently are approved for clinical use. No available vaccine is currently suitable for distribution to children in developing countries. Shigella organisms: Three vaccines have been shown to be immunogenic and protective in field trials. Parenteral vaccines may be useful for travelers and the military, but are impractical for use in developing countries. More promising is a single-dose live-attenuated vaccine currently under development in several laboratories. V. cholerae: Oral cholera vaccines are still being investigated, and their use is recommended only in complex emergencies such as epidemics. Their use in endemic areas remains controversial. In traveler’s diarrhea, oral cholera vaccine is only recommended for those working in refugee or relief camps, since the risk of cholera for the usual traveler is very low. Enterotoxigenic E. coli (ETEC) vaccines: The most advanced ETEC vaccine candidate consists of a killed whole cell formulation plus recombinant cholera toxin B subunit. No vaccines are currently available for protection against Shiga toxin-producing E. coli infection. Rotavirus: In 1998, a rotavirus vaccine was licensed in the USA for routine immunization of infants. In 1999, production was stopped after the vaccine was causally linked to intussusception in infants. Other rotavirus vaccines are being developed, and preliminary trials are promising. Currently, two vaccines have been approved: a live oral vaccine (RotaTeqì) made by Merck for use in children, and GlaxoSmithKline’s Rotarixì. Measles immunization can substantially reduce the incidence and severity of diarrheal diseases. Every infant should be immunized against measles at the recommended age. 9 Clinical Practice Adults Table: The Approach in Adults with Acute Diarrhea Perform initial assessment Dehydration ● Duration (>1 day) ● Inflammation (indicated by fever, bloody stool, tenesmus) Provide symptomatic treatment Rehydration ● Treatment of symptoms (if necessary consider bismuth subsalicylate or loperamide if diarrhea is not inflammatory or bloody) ● ● Stratify subsequent management ● Epidemiological clues: food, antibiotics, sexual activity, travel, day-care attendance, other illness, outbreaks, season ● Clinical clues: diarrhea, abdominal pain, dysentery, wasting, fecal inflammation Obtain fecal specimen for analysis ● If severe, bloody, inflammatory, or persistent diarrhea or if outbreak is suspected Consider antimicrobial therapy for specific pathogens Report to public health authorities In outbreaks save culture plates and isolates; freeze fecal and food or water specimens at -70ÆC ● Notifiable in the USA: cholera, cryptosporidiosis, giardiasis, salmonellosis, shigellosis, and infection with shiga toxin producing E. coli ● Children In 2004, WHO and UNICEF revised their recommendations for the management of diarrhea, including zinc supplementation as an adjunct therapy to oral rehydration. Since then, the recommendations have been adopted by more than 40 countries throughout the world. In countries where both the new ORS and zinc have been introduced, the rate of ORS usage has dramatically increased. TM3 / DIARRHOEAL DISEASES Table: Principles of Appropriate Treatment for Children with Diarrhea and Dehydration 10 Use ORS for rehydration Perform ORT rapidly – within 3 to 4 hours ● ● ● Administer additional ORS for ongoing losses through diarrhea When rehydration is corrected - rapid realimentation Age-appropriate unrestricted diet Continue breastfeeding Regular formula feeding No unnecessary laboratory tests or medications Treatment for Children Based on the Degree of Dehydration Table: Minimal or No Dehydration Rehydration therapy None Replacement of losses Nutrition <10 kg body weight: 60 to 120 mL Continue breastfeeding or ageappropriate normal diet ORS for each diarrheal stool or vomiting episode Note: If vomiting is persistent, the patient (child or adult) will not take ORS and is likely to need intravenous fluids. Table: Mild to Moderate Rehydration therapy ORS 50 to 100 mL/kg body Replacement of losses Nutrition <10 kg body weight: 60 to 120 mL ORS for each diarrheal stool or vomiting episode Continue breastfeeding, or resume normal diet after initial rehydration Table: Severe Dehydration Rehydration therapy Replacement of losses Nutrition Rehydrate with Ringer’s lactate (100 mL/kg) intravenously within 4 to 6 hours, then administer ORS to maintain hydration until patient recovers <10 kg body weight: 60 to 120 mL ORS for each diarrheal stool or vomiting episode Continue breastfeeding, or resume age-appropriate normal diet after initial hydration Cautionary Note: Treating a patient with severe dehydration due to infectious diarrhea with 5% dextrose with 1/4 normal saline is unsafe. Severe dehydration occurs, usually as a result of bacterial infection (cholera, ETEC), which usually leads to more sodium loss in feces (60 to 110 mmol/L). A 1/4 normal saline solution contains sodium (Na) 38.5 mmol/L, and this does not balance the sodium losses. Intravenous infusion with 5% dextrose with 1/4 normal saline will thus lead to severe hyponatremia, convulsion, and loss of consciousness. Five percent dextrose with 1/2 standard normal saline can only be used when Ringer’s lactate is not available. The main principles are: treatment of dehydration; stool cultures and microscopy to guide therapy; and frequent smaller meals with higher protein intakes. (See Figure 15 in the original guideline document for an algorithm for the therapeutic approach to acute bloody diarrhea [dysentery] in children.) ∏ome Management of Acute Diarrhea With ORS, uncomplicated cases of diarrhea in children can be treated at home, regardless of the etiologic agent. Caregivers need proper instructions regarding signs of dehydration, when children TM3 / DIARRHOEAL DISEASES The Therapeutic Approach to Acute Bloody Diarrhea (Dysentery) in Children 11 TM3 / DIARRHOEAL DISEASES appear markedly ill, or do not respond to treatment. Early intervention and administration of ORS reduces dehydration, malnutrition, and other complications and leads to fewer clinic visits and potentially fewer hospitalizations and deaths. Self-medication in otherwise healthy Indications for Patient Care adults is safe. It relieves discomfort and social ● Caregiver’s report of signs consistent with dysfunction. There is no evidence that it dehydration prolongs the illness. ● Changing mental status In adults who can maintain their fluid intake, ● Young age (<6 months old or <8 kg body ORS does not provide any benefits. It does not weight) reduce the duration of diarrhea or the number ● History of premature birth, chronic medical of stools. In developed countries, adults with conditions, or concurrent illness acute watery diarrhea should be encouraged to ● Fever >38ÆC for infants <3 months old or drink fluids and take in salt in soups and salted >39oC for children 3 to 36 months old crackers. Nutritional support with continued ● Visible blood in stool feeding improves outcomes in children. ● High-output diarrhea including frequent and Among hundreds of over-the-counter substantial volumes products promoted as antidiarrheal agents, ● Persistent vomiting, severe dehydration, only loperamide and bismuth subsalicylate persistent fever have sufficient evidence of efficacy and safety. ● Suboptimal response to ORT or inability of Principles of self-medication: caregiver to administer ORT ➠ Maintain adequate fluid intake. ● No improvement in 48 hours - symptoms ➠ Consumption of solid food should be exacerbate; overall condition gets worse guided by appetite in adults — small light 12 meals. ➠ Antidiarrheal medication with loperamide (flexible dose according to loose bowel movements) may diminish diarrhea and shorten the duration. ➠ Antimicrobial treatment is reserved for prescription only in residents’ diarrhea or for inclusion in travel kits (add loperamide). Family knowledge about diarrhea must be reinforced in areas such as prevention, nutrition, ORT/ORS use, zinc supplementation, and when and where to seek care (see “Indications for In-Patient Care” above). Where feasible, families should be encouraged to have ORS ready-to-mix packages and zinc (syrup or tablet) readily available for use, as needed. Cascades A cascade is a hierarchical set of diagnostic or therapeutic techniques for the same disease, ranked by the resources available. Table: Cascade for Acute Watery Diarrhea – Cholera-like, with Severe Dehydration Level 1 Intravenous fluids + antibiotics + diagnostic tests ● Tests: tetracycline, fluoroquinolone or other + stool microscopy/culture Level 2 Intravenous fluids + antibiotics ● Empirical: tetracycline, fluoroquinolone or other Level 3 Intravenous fluids + ORS Level 4 Nasogastric tube ORS (if persistent) (vomiting) Level 5 Oral ORS Level 6 Oral ‘home made’ ORS ● Salt, glucose, orange juice dissolved in water ➠ ➠ ➠ ❶ ➋ ➌ ➍ ➎ Notes: Tetracycline is not recommended in children. Nasogastric (NG) feeding is not very feasible for healthy and active older children, but it is suitable for malnourished, lethargic children. NG feeding requires skilled staff. Often, intravenous fluid treatment is more easily available than NG tube feeding. NG feeding (ORS and diet) is especially helpful in long-term severely malnourished children (anorexia). Table: Cascade for Acute Watery Diarrhea, with Mild/Moderate Dehydration Level 1 Intravenous fluids (consider) + ORS Level 2 Nasogastric tube ORS (if persistent vomiting) Table: Acute Bloody Diarrhea, with Mild/Moderate Dehydration Level 3 Oral ORS Level 1 Oral ORS + antibiotics consider for: ● S. dysenteriae ● E. histolitica ● Severe bacterial colitis + diagnostic tests ● Stool microscopy, culture Level 4 Oral “home made” ORS ● Salt, glucose, orange juice dissolved in water Level 2 Oral ORS + antibiotics consider for: ● Empirical antibiotics for moderate/severe illness Level 3 Oral ORS Level 4 Oral “home made” ORS ● Salt, glucose, orange juice dissolved in water TM3 / DIARRHOEAL DISEASES ➠ Cautions: If facilities for referral are available, patients with severe dehydration (at risk of acute renal failure or death) should be referred to the nearest facility with intravenous fluids (levels 5 and 6 cannot replace the need for referral in case of severe dehydration). Levels 5 and 6 must be seen as interim measures and are better than no treatment if no intravenous facilities are available. When intravenous facilities are used, it must be ensured that needles are sterile and that needles and drip sets are never reused, to avoid the risk of hepatitis B and C. Do not diagnose moderate dehydration as severe dehydration and thus initiate referral for intravenous feeding because oral rehydration is more time-consuming. It is in the mother’s interest to avoid the unnecessary complications that may be associated with using intravenous therapy. 13 Benefits/Harms of implementing the guidelines recommendatios Potential Benefits ➠ Appropriate diagnosis, treatment, and management of acute diarrhea in children and adults ➠ Reduced morbidity and mortality from acute diarrhea Potential Harms ➠ Antimicrobials: In adults, the clinical benefit of antimicrobials should be weighed against the cost, the risk of adverse reactions, harmful eradication of normal intestinal flora, the induction of Shiga toxin production, and the increase of antimicrobial resistance. ➠ Tetracycline is not recommended in children. ➠ Loperamide should be avoided in bloody or suspected inflammatory diarrhea (febrile patients). ➠ Use of ciprofloxacin or another fluoroquinolone is still controversial; use should be limited to high-risk individuals or those needing to remain well for short visits to a high-risk area. ➠ Diarrhea vaccine use remains controversial. TM3 / DIARRHOEAL DISEASES Cholera 14 Cholera is a diarrhoeal disease caused by infection of the intestine with the bacterium Vibrio cholerae, either type 01 or 0139. Both children and adults can be infected. About 20% of those who are infected develop acute, watery diarrhoea – 10–20% of these individuals develop severe watery diarrhoea with vomiting. If these patients are not promptly and adequately treated, the loss of such large amounts of fluid and salts can lead to severe dehydration and death within hours. The case-fatality rate in untreated cases may reach 30–50%. Treatment is straightforward (basically rehydration) and, if applied appropriately, should keep case-fatality rate below 1%. Cholera is usually transmitted through faecally contaminated water or food and remains an everpresent risk in many countries. New outbreaks can occur sporadically in any part of the world where water supply, sanitation, food safety, and hygiene are inadequate. The greatest risk occurs in over-populated communities and refugee settings characterized by poor sanitation, unsafe drinking-water, and increased personto-person transmission. Because the incubation period is very short (2 hours to 5 days), the number of cases can rise extremely quickly. It is impossible to prevent cholera from being introduced into an area – but spread of the disease within an area can be prevented through early detection and confirmation of cases, followed by appropriate response. Because cholera can be an acute public health problem – with the potential to cause many deaths, to spread quickly and eventually internationally, and to seriously affect travel and trade – a well coordinated, timely, and effective response to outbreaks is paramount. Response activities should always be followed by the planning and implementation of preparedness activities that will allow future cholera outbreaks to be dealt with more effectively. A strong cholera preparedness plan and programme is the best preparation for outbreaks in countries at risk of cholera, whether or not they have yet been affected, or countries in which seasonal recurrence of the disease may be expected. New Strategies: Oral Cholera Vaccines In the long term, improvements in water supply, sanitation, food safety and community awareness of preventive measures are the best means of preventing cholera, as well as other diarrhoeal diseases. However, WHO is currently evaluating the use of newer tools to complement these traditional measures. Oral cholera vaccines of demonstrated safety and effectiveness have recently become available for use by individuals. Some countries have already used oral vaccine to immunize populations considered to be at high risk for cholera outbreaks. Use of these vaccines in both endemic and epidemic situations requires further assessment. Work is under way to investigate the role of mass vaccination as a public health strategy for protecting at-risk populations against cholera. Issues being addressed include logistics, cost, timing, vaccine production capacity, and criteria for the use of mass vaccination to contain and prevent outbreaks. Case Definition Laboratory Confirmation The treatment of dehydrated patients should not be delayed until laboratory testing of samples has been completed. Microbiological confirmation of Vibrio cholerae by direct observation can be obtained immediately, but it usually takes 2 days to get culture results. It is important to gather information on: serogroup of Vibrio (O1 or O139); antimicrobial sensitivity patterns. TM3 / DIARRHOEAL DISEASES It is most important to ascertain that all patients considered to be cholera cases in fact have the same disease. According to the WHO case definition, a case of cholera should be suspected when: in an area where the disease is not known to be present, a patient aged 5 years or more develops severe dehydration or dies from acute watery diarrhoea; in an area where there is a cholera epidemic, a patient aged 5 years or more develops acute watery diarrhoea, with or without vomiting. A case of cholera is confirmed when Vibrio cholerae O1 or O139 is isolated from any patient with diarrhoea. In children under 5 years of age, a number of pathogens can produce symptoms similar to those of cholera, such as rice-water diarrhoea. To maintain specificity, therefore, children under 5 are not included in the case definition of cholera. 15 Improved Preparedness and Treatment Training of health workers is an essential element for preparedness, especially in high-risk areas. Emergency supply needs should be evaluated in the light of the particular situation: likely attack rate in refugee camps, with high-risk populations (because of malnutrition), is 5-8%; in open settings, an attack rate of 0.2% might be used; in rural communities of 5000 people or less, the attack rate might reach 2%. Emergency stocks of basic supplies should be prepared so that they can be mobilized quickly. Rehydration Rehydration with replacement of electrolytes lost is the mainstay of cholera treatment. According to the dehydration stage (A, B, C), the patient should receive different rehydration therapy (oral or intravenous fluids). Oral rehydration solution (ORS) should be used during and after IV therapy. Surveillance of the patient is crucial during the early stage of treatment. Dehydration stage Severe Mild TM3 / DIARRHOEAL DISEASES No dyhydration 16 Signs Treatment Lethargic, unconscious, floppy Very sunken eyes Drinks poorly, unable to drink Mouth very dry Skin pinch goes back very slowly No tears (only for children) IV therapy + antibiotics + Restless and irritable Sunken eyes Dry mouth Thristy, drinks eagerly Skin pinch goes back slowly No tears (only for children) ORS + None of the above signs ORS at home ORS + very close surveillance Intravenous Therapy for Severe Cases Ringer’s lactate is the preferred IV fluid. Normal (9%) saline or halfnormal saline with 5% glucose can also be used, but ORS solution must be given at the same time to replace the missing electrolytes. Plain glucose solution is not effective in rehydrating cholera patients. When IV rehydration is not possible and the patient cannot drink, ORS solution can be given by nasogastric tube. However, nasogastric tubes should not be used for patients who are unconscious. Antibiotics They should be given only in severe cases, to reduce the duration of symptoms and carriage of the pathogen. Antimicrobial resistance is increasing. In most countries Vibrio cholera is resistant to cotrimoxazole; in some settings it has also developed resistance to tetracycline. The laboratory should be asked about patterns of resistance of the strain at the beginning of and during the outbreak: antibiotic sensitivity to antibiotics may return after a certain period. Mass chemoprophylaxis is not effective in controlling a cholera outbreak. Selective chemoprophylaxis (one dose of doxycycline) may be useful for members of a household who share food and shelter with a cholera patient. However, in societies where intimate social mixing and the exchange of food between households are common, it is difficult to identify close contacts. Nevertheless, chemoprophylaxis may be useful when a cholera outbreak occurs in a closed population, such as a prison. Health Education The most important messages to prevent the family from being contaminated are: FOOD SAFETY Cholera and dysentery can be transmitted through contaminated food. Food may be contaminated before, during or after preparation. Raw or undercooked seafood, and foods cooked and then kept at room temperature for several hours are especially dangerous. Fruits and vegetables may be contaminated if they were fertilized with human waste (nightsoil), irrigated with contaminated water or “freshened” with contaminated water. HAND WASHING People can prevent the transmission of cholera and dysentery by washing their hands. Careful and frequent hand-washing is especially important to stop the transmission of dysentery. If soap is expensive, or not available, ashes or mud can be used instead. Children, as well as adults, should wash their hands. Hand Washing is highly recommended: TM3 / DIARRHOEAL DISEASES ENSURE A SAFE SUPPLY OF WATER Access to safe water is a basic requirement for health, and it is more critical when there is an outbreak of diarrhoeal disease. Since contaminated water can be the source of cholera and epidemic dysentery, every effort must be made to provide safe drinking- water, and safe water for food preparation and for personal hygiene. Each person should have at least 20 litres of water a day for drinking, cooking and washing. Health facilities need 40-60 litres per patient a day to maintain adequate levels of hygiene. Every family should know how to treat water so that it will be safe for drinking. Piped water, or water that is delivered in trucks or drums, must be adequately chlorinated. Environmental sanitation workers can test water to be sure that the amount of chlorine is adequate. Other sources of water are usually contaminated (e.g. rivers, shallow wells), so you must take measures to reduce the risk of people becoming ill. You may have to close the water source or provide another source of safe water. If that is not possible, be sure that people using the water know how to make it safe. 17 ➠ ➠ ➠ ➠ ➠ after defecation after any contact with stools (cleaning up after children or patients) before preparing food before eating food before feeding children. ENVIRONMENTAL SANITATION In the long term, cholera and dysentery will become rare as environmental hygiene and water supplies improve. However, in areas where sanitation is poor, you must use temporary measures to guarantee that stools are disposed of safely when there is an outbreak of diarrhoeal disease. The methods to apply are: ➠ not to defecate on the ground or near a water supply ➠ to wash hands with soap or ash after any contact with stools ➠ to dispose of children’s stools in toilets, in latrines, or to bury the stools ➠ to build and use latrines ➠ if there is no latrine, to bury the stools away from water sources, as a temporary measure. ➠ safe practices at funerals (discourage ritual washing of the dead, hold the funeral soon after death ensure that people who clean up and prepare the body in the hospital do not prepare food or serve food etc) TM3 / DIARRHOEAL DISEASES INEFFECTIVE CONTROL MEASURES The measures described in this section do not stop the spread of epidemics. However, pressure to use them may come from a frightened public or from uninformed officials. When ineffective measures are carried out, it gives a false sense of security, and wastes time and resources that could be used on efforts that are truly effective. 18 Vaccination: No vaccine currently exists for Shigella dysenteriae type 1. The old parenteral cholera vaccine is not recommended. Two new oral cholera vaccines offer high-level short-term protection; they are available for use in travellers in a few countries, but are not yet recommended for large scale public health use. Trade and travel restrictions (cordon sanitaire): It is not possible to detect and isolate all infected travellers, most of whom have no signs of illness. A cordon sanitaire requires setting up checkposts and restricting movement. This diverts substantial resources from more effective control measures. Trade and travel restrictions disrupt the economy of an area, which may encourage suppressing information about outbreaks. Mass chemoprophylaxis for cholera: Mass chemoprophylaxis – treating an entire community with antibiotics – does not limit the spread of cholera. In some places, it contributed to making the vibrio resistant to antibiotics, which deprives severely ill patients of a valuable treatment. Selective chemoprophylaxis is usually not recommended. It is justified only if surveillance shows that the secondary attack rate in the community is high (an average of at least one household member in five becoming ill after the first case occurs in the household). If selective chemoprophylaxis is used, it should be given to all close contacts as soon as possible after the initial case is recognized. The prophylactic dose of antibiotics is the same as the therapeutic dose. Doxycycline is preferred because only a single dose is needed. Antibiotic chemoprophylaxis for dysentery: Giving people antibiotics for dysentery before they become ill does not prevent dysentery and worsens the problem of antibiotic resistance. It should never be done. Surveillance of Patients with Severe Cholera Surveillance and regular reassessment of patients for the following are crucial: ➠ pulse; ➠ dehydration signs; ➠ number and appearance of stools; ➠ respiratory rhythm; ➠ temperature (cholera usually provokes hypothermia – if the temperature is high there may be associated pathology, e.g. malaria); ➠ urine (present or not); ➠ state of consciousness. Complications ➠ pulmonary oedema if excessive IV fluid has been given; ➠ renal failure if too little IV fluid is given; ➠ hypoglycaemia and hypokalaemia in children with malnutrition rehydrated with Ringer lactate only. References ñ Centers for Disease Control and Prevention. Managing acute gastroenteritis among children: oral rehydration, maintenance, and nutritional therapy. Atlanta, GA: Centers for Disease Control and Prevention – Federal Government Agency [U.S.]. 2003 Nov 21. ñ UNICEF/WHO. Clinical management of acute diarrhea: UNICEF/WHO Joint Statement, May 2004 http://www.who.int/child-adolescent-health/New_Publications/CHILD_HEALTH/ISBN_92_4_159421_7.pdf ñ World Health Organization. Production of zinc tablets and zinc oral solutions: guidelines for programme managers and pharmaceutical manufacturers. Geneva: World Health Organization http://www.who.int/ child-adolescent-health/publications/CHILD_HEALTH/ISBN_92_4_159494_2.htm ñ World Health Organization. The treatment of diarrhea: a manual for physicians and other senior health workers, 4th rev. ed. Geneva: World Health Organization, 2005 http://www.who.int/child-adolescenthealth/New_ Publications/CHILD_HEALTH/ISBN_92_4_159318_0.pdf ñ The treatment of diarrhoea – a manual for physicians and other senior health workers. Geneva, World ñ WHO recommended strategies for prevention and control of communicable diseases. Geneva, World Health Organization, 2001 (WHO/CDS/CPE/SMT/2001.13). ñ Hanquet G. Refugee health – an approach to emergency situations. London, Médecins Sans Frontières/Macmillan, 1997. ñ Guidelines for cholera control. Geneva, World Health Organization, 1993. ñ Guidelines for the collection of clinical specimens during field investigation of outbreaks. Geneva, World Health Organization, 2000 (WHO/CDS/CSR/EDC/2000.4). ñ Handbook for emergency field operations. Geneva, World Health Organization, 1999 (EHA/FIELD/99.1). TM3 / DIARRHOEAL DISEASES Health Organization, 1995 (WHO/CDR/95.3). 19 Case Study Rivas Distict outbreak Read the descriptions and then write brief answers to the questions (write key words instead of complete sentences). You may look in your modules, if you need help in answering the questions. Notify the facilitator if you cannot understand a question, and when you have finished. There will be a discussion afterwards. Background Rivas District has a population of 100 000. About half the people live in Rivas Town, and the others live in scattered villages. The town, which has piped water and sewerage, includes a very crowded neighbourhood, Bayside, where sanitation is poor and there is no trained health worker. Village A is a prosperous farming village, with a well-functioning health centre. Most families have latrines and get water from a borehole. Some people in Village A use shallow wells during the rainy season (October to March) because the wells are closer than the borehole. Village B (about 5000 people) is further from the town, on poor roads, and has a health post staffed by a nurse who has not been trained in case management of diarrhoea in years. The nurse is unhappy at being posted to a rural clinic, and often escapes to town. Water is from shallow wells and the river, and very few families have latrines. The district shares a border with the neighbouring country, and there is much traffic across the border, especially during the yearly festival in Rivas Town. There was an outbreak of cholera in 1991, but none has been reported since then. The District Medical Officer wants to be sure the district is ready if another outbreak occurs. Q 1: What are the main things that should be done to prepare for an outbreak? Q 2: If cholera or epidemic dysentery should appear in the district, are there groups or individuals at high risk of getting ill? Are there any at high risk of dying, once they are ill? Name them and explain why you think they are at risk. High risk of getting ill: High risk of dying once ill: TM3 / DIARRHOEAL DISEASES Week of 9-15 January 20 The District Medical Officer has made an Epidemic Preparedness Plan. On Monday, the District Medical Officer gets a phone call from the nurse in village A. The nurse is concerned because a 4year-old boy from the village presented to the clinic with severe dehydration caused by acute watery diarrhoea, and died while being treated. Q 3: Should the District Medical Officer start the Epidemic Preparedness Plan? Explain why or why not. The nurse from village A calls again on Tuesday. She has treated the sister, the mother and the father of the boy who died, all for acute watery diarrhoea. She has also treated 6 other people from village A for acute watery diarrhoea. The District Medical Officer asked the nurse to tell him the age of each patient, their degree of dehydration and the outcome of their treatment. These were the cases: Patient Degree of dehydration Outcome 14-year-old sister severe mild moderate severe moderate severe severe severe mild recovered recovered recovered recovered recovered recovered recovered died recovered 50-year-old father 45-year-old mother 20-year-old woman 28-year-old man 5-year-old boy 10-month-old girl 65-year-old man 3-year-old boy Q 4: On the list above, put a check next to each patient who meets the casedefinition for reporting a case of cholera. Q 5: Should the District Medical Officer start the Epidemic Preparedness Plan? Explain why or why not. The District Medical Officer decided to call a meeting of the Epidemic Control Committee. Q 6: What four things do you think the Epidemic Control Committee should do first? Q 7: What are the duties of the Epidemic Control Committee? Week of 16-22 January There have been more cases of cholera in village A. The nurse and the District Medical Officer investigated the cases in village A. They found that, about a week before the four-year-old became ill, he and his family had attended the funeral in village B of a man who died of diarrhoea. The District Medical Officer checked the records, and found that the nurse posted to village B had not sent in any reports for two months. Q 8: What should the District Medical Officer do? Week of 23-29 January The District Medical Officer receives a laboratory report that confirms cholera. The Rivas Epidemic Control Committee decides to send a Mobile Control Team to village B to open a Temporary Treatment Centre. Q 10: What should the team look for when choosing a site for the Temporary Treatment Centre? When they arrived in village B, the Mobile Control Team found that cases that met the cholera case-definition had been occurring there since before the first cases in village A. The first cases in village A happened in the week of 9-15 January. The team made this table: TM3 / DIARRHOEAL DISEASES Q 9: What control measures should NOT be carried out? 21 Village B Cases Deaths 2-8 Jan 9-15 Jan 16-22 Jan 23-29 Jan 15 3 50 5 65 3 51 0 Q 11: In what week was there the highest number of deaths? In what week did patients with suspected cholera have the greatest risk of dying? Q 12: How could the deaths have been prevented? Cholera has arrived in Rivas Town and is spreading in the crowded Bayside neighbourhood. The town officials urge the District Medical Officer not to say there is an outbreak, because the town’s yearly festival is only two weeks away, and they fear that people will not come when there is news of an outbreak. Q 13: What should the District Medical Officer do? The epidemic has declined in villages A and B, but continues in the town. Water testing has shown that the town’s piped water is not sufficiently chlorinated. An environmental health technician also discovered that people in bayside area had dug holes down to the water mains and pierced the mains. This created little wells” from which they got water. It also allowed contamination into the water mains. Q 14: What should be done? Teams were sent to Bayside to look for patients and to educate the community there on prevention measures. These are the problems that the team found: a. the residents could not afford soap b. the residents could not afford the fuel needed to boil their water c. men who worked far from home usually carried a home-cooked lunch with them to work, and ate the lunch 6-8 hours after it had been cooked. TM3 / DIARRHOEAL DISEASES Q 15: What advice should the team give to solve each problem? a. (soap) b. (fuel needed to boil the water) c. (home-cooked lunch eaten 6-8 hours after it had been cooked). 22 Week of 6-12 January The District Medical Officer did send notification of the urban outbreak of cholera, and began an intensive health education campaign. Many people came to the festival, although fewer than in the past. Many visitors arrived from the neighbouring country. Q 16: What precautions should be observed to safeguard the health of the people who attend the festival? Health officials in the neighbouring country got news of the cholera outbreak the day before the festival ended. They read about it in the newspaper and immediately ordered border guards to screen all returning travellers for signs of diarrhoea, and to isolate those who were ill. Q 17: Will this keep the outbreak from spreading? Explain your answer. Week of 13-19 January The outbreak ended. Q 18: What should the District Medical Officer and the communities involved do now? FIELD EXERCISE Cholera Treatment Center – Setting up a CTC General Objective To provide participants with basic principles of setting up a Cholera Treatment Center (CTC). Specific objectives Content Case scenario: A Cholera outbrake occur in a big slum close to your mission area. Your team has set up a Cholera Treatment Center behind the local hospital. You are about to screen and treat a few thousands the next weeks. A few of them should be admitted for parenteral support. Design an overall map of the CTC and try to find practical ways to make better use of the space. TM3 / DIARRHOEAL DISEASES At the end of the exercise, participants will be familiar with: ➠ Screening, admission and observation ➠ Hospitalisation of severely dehydrated patients ➠ Recovery ➠ Neutral area ➠ Mortuary ➠ Water, Hygiene and Sanitation 23 Design and architecture of a CTC: the principles Organisation and design of a CTC are based on simple principles and rules. Patients are first screened and diagnosed, then sent to specific areas for treatment according to their status. The CTC is organised in separate areas, following two key principles: ➠ Isolation of the entire facility from other public structures (dispensary, school, market) ➠ Separation of patients (contaminated area) from the “neutral area” (not contaminated) Suspect patient = screening + ORS medical examination No dehydration No diarrhea No vomiting No dehydration or mild dehydration Mild / moderate diarrhea and / or vomiting Severe dehydration or uncontrollable vomiting No Simple cholera Severe cholera Send to normal dispensarey Oral rehydration Immediate IV rehydration TM3 / DIARRHOEAL DISEASES Screening, admission and observation 24 Patients are examined by a medical person for screening. If cholera, admit; otherwise send to normal dispensary. Patients are admitted with 1 attendant (caregiver). Patients who are admitted are registered (cholera register). Moderate or mild cases receive oral rehydration therapy in observation where they stay under medical observation for 6 hours . Patients stay under tents or shelters, on mats or benches and will be discharged directly from there. Severely dehydrated persons or those with uncontrollable vomiting should be hospitalized directly: see hospitalization Hospitalisation of severely dehydrated patients Patients with severe dehydration and/or uncontrollable vomiting must be hospitalized for immediate rehydration. Each patient lies on a pierced bed with 1 bucket for stool collection underneath + 1 bucket for vomit besides the bed. Patients needing specific management (children, elderly, pregnant women) should be regrouped in specific wards. Do not exceed 20 patients per ward. Recovery For oral rehydration after hospitalisation when less surveillance is required. Patients stay on mats or benches, as in the observation area. Neutral area Includes office space, rest area, changing room for staff, pharmacy and logistic stores, water storage, preparation of chlorine solutions, kitchen. Logistic store and pharmacy must be organized to ensure at least 7 days autonomy. In case of reduced access/security constraints, stocks should be increased to avoid any shortage. Mortuary Must be isolated from other areas. Water, Hygiene and Sanitation ➠ 60 litres of safe (chlorinated) water are needed per 1 CTC patient per day (this includes needs for drinking water, food, hygiene of the patient and the caregiver). ➠ S u fficient storage capacity for 3 days must be ensured in order to avoid any shortage. ➠ Label and clearly differentiate each container (drinking water, ORS, chlorine solutions). ➠ 0.05% chlorine for hand washing, dish rinsing and bathing of soiled patients, 0.2% chlorine for disinfecting floors, beds, clothes and footbaths, and 2% for disinfecting of vomit, faeces and corpses. Hospitalisation wards 20 patients per ward Neutral area Store, Office, Kitchen, Observation area = ORS Recovery Morgue Entry Waste area Screening Admission Exit TM3 / DIARRHOEAL DISEASES Staff Entry 25