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1 Running head: HEPATITIS B HEPATITIS B by Sonia Donaires Applied Research Project Paper Submitted in Partial Fulfillment Of the Requirements For the Degree of Master in Public Health MPH 500 Concordia University Nebraska Dr. Evelyn Davila January 26, 2015 HEPATITIS B 2 Executive Summary This is a research review about descriptive epidemiology for Hepatitis B. Hepatitis B virus is an infections disease that is present worldwide. According to WHO, people infected for Hepatitis B (HBV) virus are estimated 400 million with chronic infection and approximately one million of deaths every year worldwide. Hepatitis B is a virus (HBV). The HBV is a small DNA virus classified in the virus family Hepadnaviridae. Once the HBV virus is inside of the liver can cause damage to the liver cells and progress in lever cancer that can be fetal for people. Hepatitis B progression starts with an acute infection and go into the chronic infection that can lead to cirrhosis. The cirrhosis can lead to a liver failure or liver cancer and lead to death of the patient. Hepatitis B virus is mostly sexually transmitted disease. Symptoms can vary from mild to severe infection. The most important symptoms include joint pain, nausea and vomiting, weakness and fatigue and jaundice. A preventive measurement taken against Hepatitis B is vaccination. The prevalence of Hepatitis B varies in each country. Globally, the prevalence of Hepatitis B was categorized as high, intermediate and low endemicity. According the CDC, countries with low endemicity are those that belong to the developed countries and high endemicity for developing countries. The vaccine is one of the principal factors that regulate the morbidity and mortality in each country. Today Hepatitis B is still one of the infectious diseases with high incidence in the world and it can be treated and prevented. The principal sources for this research was a review of a data, tables and statistics found in the CDC and WHO along with others projects of investigation about Hepatitis B that help me to finalized the requirements of this research. Data about the socioeconomic factor was hard to find especially for the United States, probably because the incidence in US is low compared with HEPATITIS B 3 countries with high incidence. However, it was easy to find in cross sectional studies have done in countries with major incidence of Hepatitis B. i.e. developing countries. HEPATITIS B 4 Hepatitis B Define the problem The hepatitis B virus is an infectious disease present worldwide, two billion (1 out of 3 people) people have been infected with hepatitis B virus (HBV), 400 million have chronic infection, This is a research review about descriptive epidemiology for Hepatitis B. Hepatitis B virus is an infections disease that is present worldwide. According to WHO, people infected for Hepatitis B (HBV) virus are estimated 400 million with chronic infection and approximately one million of deaths every year worldwide. Hepatitis B is a virus (HBV). The HBV is a small DNA virus classified in the virus family Hepadnaviridae. Once the HBV virus is inside of the liver can cause damage to the liver cells and progress in lever cancer that can be fetal for people. Hepatitis B progression starts with an acute infection and go into the chronic infection that can lead to cirrhosis. The cirrhosis can lead to a liver failure or liver cancer and lead to death of the patient. Hepatitis B virus is mostly sexually transmitted disease. Symptoms can vary from mild to severe infection. The most important symptoms include joint pain, nausea and vomiting, weakness and fatigue and jaundice. A preventive measurement taken against Hepatitis B is vaccination. The prevalence of Hepatitis B varies in each country. Globally, the prevalence of Hepatitis B was categorized as high, intermediate and low endemicity. According the CDC, countries with low endemicity are those that belong to the developed countries and high endemicity for developing countries. The vaccine is one of the principal factors that regulate the morbidity and mortality in each country. Today Hepatitis B is still one of the infectious diseases with high incidence in the world and it can be treated and prevented. The principal sources for this research was a review of a data, tables and statistics found in the CDC and WHO along with others projects of investigation about Hepatitis B that help me to finalized the requirements of this research. Data about the socioeconomic factor was hard to find especially for the United States, probably because the incidence in US is low compared with countries with high incidence. However, it was easy to find in cross sectional studies have done in countries with major incidence of Hepatitis B. i.e. developing countries. HEPATITIS B 5 10 to 30 million will become infected each year, 600.000 die each year from HBVrelated liver disease or hepatocellular carcinoma, and approximately 2 people die each minute from Hepatitis B. Globally, it is estimates that 5% of the populations are chronic carriers of HBV, and nearly 25% of all carriers develop serious liver diseases such as chronic hepatitis, cirrhosis, and primary hepatocellular carcinoma (liver cancer). HBV infection causes more than one million deaths every year. (WHO, 2015) According to the statistics in the United States, 12 million Americans have been infected (1 out of 20 people) with hepatitis B virus, more than one million people are chronically infected, up to 40,000 new people will become infected each year, 5,000 people will die each year from hepatitis B and its complications and approximately 1 health care worker dies each day from hepatitis B. (Hepatitis B Foundation, 2014) Most healthy adults (90%) who are infected will recover and develop protective antibodies against future hepatitis B infections. A small number (5-10%) will be unable to get rid of the virus and will develop chronic infections. Unfortunately, this is not true for infants and young children 90% of infants and up to 50% of young children infected with hepatitis B will develop chronic infections. Therefore, vaccination is essential to protect infants and children. Hepatitis B is 100 times more infectious than the AIDS virus, yet it can be prevented with a safe and effective vaccine. (Hepatitis B Foundation, 2014) Hepatitis B Virus (HBV) Hepatitis B (HBV) is a DNA virus classified in the virus family Hepadnaviridae. Humans are the only known natural host. HBV enters the liver via the bloodstream, and replication occurs HEPATITIS B 6 only in liver tissue. Hepatities B virus has a small circular DNA genome that is partially doublestranded. HBV contains numerous antigenic components, but the three antigens related with Hepatitis B are: HBsAg, HBcAg and HBe Ag. HBcAg is the nucleocapsid protein core of HBV. HBcAg is not detectable in serum by conventional techniques, but it can be detected in liver tissue of persons with acute or chronic HBV infection. HBeAg is a soluble protein, also contained in the core of HBV. HBeAg is detected in the serum of persons with high virus titers and indicates high infectivity. Antibody to HBsAg (anti-HBs) develops during convalescence after acute HBV infection or following hepatitis B vaccination. The presence of anti-HBs indicates immunity to HBV. Antibody to HBcAg (anti-HBc) indicates infection with HBV at an undefined time in the past. IgM class antibody to HBcAg (IgM anti-HBc) indicates recent infection with HBV. Antibody to HBeAg (anti-HBe) becomes detectable when HBeAg is lost and is associated with low infectivity of serum. (CDC, 20015) Hepatitis B virus (HBV) is a noncytopathic virus. The HBV virus does not cause direct damage to liver cells. Instead, it is the immune system’s aggressive response to the virus leads to an inflammation and damage the liver (hepatitis). Once the HBV virus inside of the liver, cause damage to the genetic material of the liver cells produces cancer, which it can be fatal for the human. (Hepatitis B foundation, 2014) Transmission of Hepatitis B The virus is transmitted by exposure to HBsAg-positive body fluids from persons who have acute or chronic HBV infection. The highest concentrations of virus are in blood and serous fluids; lower concentrations of virus are found in other fluids, such as saliva and semen. Saliva can be a vehicle of transmission through bites. The hepatitis B virus can HEPATITIS B 7 survive outside the body for at least 7 days. During this time, the virus can still cause infection if it enters the body of a person who is not protected by the vaccine. The hepatitis B virus is not spread by contaminated food or water, and cannot be spread casually in the workplace. The incubation period of the hepatitis B virus is 75 days on average, but can vary from 30 to 180 days. The virus may be detected 30 to 60 days after infection and persists for variable periods of time. (WHO, 2014) The most common ways of transmissions are: Unprotected sexual intercourse with an infected. In the United States, the most important route of transmission is by sexual contact, either heterosexual or homosexual, with an infected person. Transmission occurs among men who have sex with men, possibly via contamination from asymptomatic rectal mucosal lesions. Using a syringe that was previously used by an infected person (most commonly happens with drug addicts and people who inject steroids). Having your skin perforated with unsterilized needles, as might be the case when getting a tattoo, or being accidentally pricked. Early childhood transmission in highly endemic areas with HBV is most commonly spread from mother to child at birth or from person to person in early childhood. People who work in health care are in risk of becoming infected by accident. Symptoms of Hepatitis B When first infected, a person can develop an acute infection that refers to the first 6 months after the individual is exposed to the hepatitis B virus. Acute HBV infection is characterized by the presence of HBsAg and immunoglobulin M (IgM) antibody to the core HEPATITIS B 8 antigen, HBcAg. During the initial phase of infection, patients are also seropositive for HBeAg. Chronic Hepatitis B refers to the illness that occurs when the Hepatitis B virus remains in a person’s body. Chronic infection is characterized by the persistence (>6 months) of HBsAg (with or without concurrent HBeAg). Persistence of HBsAg is the principal marker of risk for developing chronic liver disease and hepatocellullar carcinoma (HCC) later in life. The presence of HBeAg indicates that the blood and body fluids of the infected individual are highly contagious (WHO, 2015) Over time, the infection can cause serious health problems that lead to a chronic or lifelong, illness. Some people are able to fight the infection and clear the virus. For others, the infection remains to a chronic or lifelong illness. The symptoms vary from mild to severe; usually appear about one to 6 months after the person is infected. Signs and symptoms of hepatitis B may include: abdominal pain, dark urine, fever, joint pain, loss of appetite, nausea and vomiting, weakness and fatigue and yellowing of your skin and the whites of your eyes (jaundice). Treatment and Prevention of Hepatitis B The treatment for acute hepatitis B is adequate nutritional balance, and replacement of fluids that are lost from vomiting and diarrhea. Chronic hepatitis B requires some drugs, such as Tenofovir and Enteravir. When it complicates with liver cancer, chemotherapy can prolong life for up to a few years. The best prevention is the vaccines for Hepatitis B virus especially in pregnant women for HBsAg, routine vaccination of infants, vaccination of adolescents, and vaccination of adults at high risk for infeccion. For pediatric and adult formulations of Recombivax HB are approved for use in any age group. (WHO, 2015) HEPATITIS B 9 Morbidity and Mortality in the United States Morbidity in US In the United States, the morbidity in 2011 had a total of 2,890 cases of acute hepatitis B were reported nationwide to CDC. The overall incidence rate for 2011 was 0.9 cases per 100,000 populations. The graph shown below that the number of reported of acute hepatitis B decreased 64%, from 8,036 in 2000 to 2,890 in 2011. Source: http://www.cdc.gov/nchhstp/ In 2011, a total of 39 states submitted 39,636 reports of chronic hepatitis B to CDC. Thirteen states agreed to publication of their NNDSS data for this report, representing 29.7% (n=11,781) of all reports of chronic hepatitis B received by CDC. In 2011, the greatest number of reports was received from California (n=9,386), representing 80.0% of all reports received; however, this count included both confirmed and probable case reports. HEPATITIS B 10 The range in the number of reports of chronic hepatitis B, which contained only confirmed reports, was 22 received from Montana to 1,333 received from Pennsylvania. Number of laboratory-confirmed, chronic hepatitis B case reports National Notifiable Diseases Surveillance System (NNDSS), 2011 No. chronic hepatitis B State case reports submitted Arizona California Iowa Louisiana Maine 55 9,386§ 55 144 64 Missouri 278 Montana 22 Oregon Pennsylvania South Carolina 180 1,333 147 South Dakota 51 Vermont 36 Wyoming 30 Total 11,781 Source: http://www.cdc.gov/nchhstp/ HEPATITIS B 11 Mortality in US The table below shows that from 2006 through 2010, hepatitis B accounted for more deaths than hepatitis A but fewer deaths than hepatitis C. In 2010, the mortality rate for hepatitis B was 0.5 deaths per 100,000 population (n=1,792). In 2010, the highest mortality rates by age, race/ethnicity and sex were observed among persons aged 55–64 years (1.7 deaths per 100,000 population), Asians and Pacific Islanders (3.0 deaths per 100,000 population), and males (0.8 deaths per 100,000 population) respectively. From 2006 through 2007, the mortality rate increased among persons aged 55–64 years, from 1.4 deaths per 100,000 population in 2006 to 1.7 deaths per 100,000 population in 2007. There was a slight decrease in 2008 to 1.6 deaths per 100,000 populations and then an increase back to 1.7 deaths per 100,000 populations in 2010. (CDC, 2013) Number and rate* of deaths with hepatitis B listed as a cause of death†, by demographic characteristic and year — United States, 2006–2010 Demographic characteristic 2006 2007 2008 2009 2010 No. Rate No. Rate No. Rate No. Rate No. Rate Age 0–34 48 0.03 62 0.04 44 0.03 39 0.03 48 0.03 Group 35–44 192 0.44 184 0.43 154 0.36 143 0.34 142 0.35 45–54 527 1.22 532 1.21 533 1.20 469 1.05 448 1.00 55–64 442 1.40 546 1.67 523 1.55 547 1.57 610 1.67 65–74 270 1.43 266 1.37 271 1.35 254 1.22 296 1.36 ≥75 226 1.23 225 1.21 263 1.40 245 1.30 248 1.34 (years) HEPATITIS B 12 White§ Race 1,011 0.38 1,081 0.40 1,093 0.40 978 0.35 Black¶ 344 1.01 359 1.03 327 0.92 320 0.87 Non-White, 350 2.12 375 2.16 368 2.05 399 2.15 non-Black** Race/ White, non856 0.34 Ethnicity Hispanic Black, non356 0.94 Hispanic 136 0.43 Hispanic Asian/Pacific 421 2.95 Islander American 17 0.73 Indian/Alaskan Native Sex Male Female Overall 1,256 0.85 1,345 0.88 1,315 0.85 1,267 0.80 1,316 0.81 449 0.27 470 0.28 473 0.27 430 0.24 476 0.27 1,705 0.54 1,815 0.56 1,788 0.54 1,697 0.51 1,792 0.52 * Rates for race, sex, and overall total are age-adjusted per 100,000 U.S. standard population. †Cause of death is defined as the underlying cause of death or one of the multiple causes of death and is based on the International Classification of Diseases, 10th Revision (ICD-10) codes B16, B17.0, B18.0, and B18.1(hepatitis B). §Included white, non-Hispanic and white Hispanic. ¶Included black, non-Hispanic and black Hispanic. **Included all other racial/ethnic groups. Source: CDC. National Vital Statistics System. HEPATITIS B 13 Distribution of Hepatitis B Host Characteristics In many low risk regions of the world, the highest incidence of HBV is seen in teenagers and young adults. In endemic areas of Africa and Asia, most infections occur in infants and children. In 2011, the highest rates of HBV were among persons aged 30–39 years (2.00 cases/100,000 population), and the lowest were among adolescents and children aged <19 years (0.04 cases/100,000 population). (CDC, 2015) Age According to the graph in the United States, declines were observed in all age groups. In 2011, the highest rates were among persons aged 30–39 years (2.00 cases/100,000 population), and the lowest were among adolescents and children aged <19 years (0.04 cases/100,000 population). HEPATITIS B 14 Source: CDC Gender In 2011, the rate of HBV in the US was 1.7 times higher among males than among females (1.18 cases and 0.69 cases per 100, 000 population, respectively). Incidence of acute hepatitis B, by sex in United States, 2000-2011. While the incidence rate of acute hepatitis B remained higher for males than females, the gap has narrowed between 2000 and 2011. Incidence rates of acute hepatitis B decreased for both males and females from 2000 through 2011. In 2011, the rate for males was approximately 1.7 times higher than that for females (1.18 cases and 0.69 cases per 100, 000 population, respectively). Source: http://www.cdc.gov/nchhstp/ HEPATITIS B 15 Ethnic Group The incidence of HBV infection in the U.S. differs significantly by race and ethnicity with the highest rates among blacks; rates are higher among Hispanics than non-Hispanics. The graph below shows that a total of 11,500 chronic hepatitis B cases were reported by eight sites in 2011. New York City reported the greatest number of cases (n=6,956; 60.5%) compared with other sites. San Francisco reported the highest rate of chronic HBV infection, with 113 cases per 100,000 populations. The percentage of male cases at the eight sites ranged from 51% - 61%. Among the 5,155 cases for which race/ethnicity was known, Asian/Pacific Islanders accounted for the highest number of chronic HBV cases (n=3,031, 59%) reported from all sites. For all sites, the highest proportion of cases (n=8,088; 70.3%) was among persons aged 25–54 years. Among all cases for whom place of birth was known, those born outside the United HEPATITIS B 16 States accounted for the highest number of chronic HBV cases (n=2,981) reported from all sites. HBsAg was the most common HBV laboratory marker used to confirm a case of chronic hepatitis B (95 %); however, HBV DNA positive test results were also reported for 72% of cases. Environmental Attributes Geographical areas The geographical distribution of the prevalence of chronic Hepatitis B virus infection in 2002, shows that the global epidemiology of HBV infection is described according to three categories of endemiity: high, intermediate, and low. Depending on the proportion of the HEPATITIS B 17 population that is seropositive for HBsAg . Countries with high endemicity are those where HBsAg seroprevalence is greater than or equal to 8%; countries with intermediate endemicity are those where seroprevalence is 2–7%; and those with low endemicity are those where seroprevalence is less than 2 percent. HBsAg seroprevalence has marked geographic variations, and the degree of HBV endemicity often correlates with the predominant mode of transmission. Countries with high level of prevalence of Hepatitis B are: china, Indonesia, Nigeria, and much of the rest of Asia and Africa Countries with intermediate prevalence of hepatitis B are Southern Europe, the Middle East, and South Asia. In Italy, Russia, and Turkey, the prevalence of chronic HBV infection ranges from 3 to 10%. Countries with low levels of endemicity are: Most of Central and South America. However, the western amazon basin, including Brazil and Peru, is a highly endemic area, with observed HNcAg seroprevalence rates greater than 10%. Many developed nations, including the United States have low endemicity category. Although anti-viral therapies can suppress HBV and delay liver disease progression, most people with chronic HBV infection reside in developing countries with limited health care resources. Thus, HBV-related HCC incidence is projected to increase for at least two decades due to the high prevalence of chronic HBV infection throughout the world. HEPATITIS B 18 Geographic Distribution of Prevalence of Hepatitis B virus infection in the world by country 2010 Source: http://www.who.int/csr/disease/hepatitis/en/. Social and Economic Factor The hepatitis B viruses (HBV) are major etiological factors in the occurrence of hepatocellular carcinoma (HCC) worldwide, but most especially in developing countries where the majority of liver cancer cases can be found. In parallel with the geographic distribution of HCC, high levels of HBV endemicity are concentrated in the developing world. The association between chronic infection with HBV and low social class is quite strong; socioeconomic factors such as low educational attainment, lower social stratum, and crowded urban residence have been reported to predict higher HBV chronic carrier prevalence in both developed and developing countries. More importantly, the effect of poverty on HBV endemicity is clearly evident among younger age groups, and earlier chronic HBV infection seems to increase the risk HEPATITIS B 19 of development of HCC. It would appear that the striking correlation between HCC and low socioeconomic status is largely related to the impact of poverty on the spread of HBV. (Stuver, SO, Boschi-Pinto, C. & Trichopoulos D., n.d.) A study of the socioeconomic factor of Hepatitis B was done in Nigeria. The finding of a significantly higher sero-prevalence of HBV infection among patients aged 40-60 years is similar to the reports on the age predilection for HBV infections from the country. According to these reports, sero-prevalence of HBsAg increases with age. According to the table shown below, the study observed that artisans had significantly higher sero-prevalence of HBsAg compared with other occupational groups. The artisans are more likely to have clustering of risk factors such as history of multiple unprotected sexual intercourse. This factor among others may encourage exposure to HBV infection. In addition, the significantly higher sero-prevalence among the artisans in this study could be a reflection of the male predominance of artisan occupation. The reported gender epidemiological pattern of HBV infections in the endemic areas of sub-Sahara Africa was in favor of the male sex and a rapid decline in HBsAg titres in females. HEPATITIS B Socio-demographic characteristics as related to HBsAg sero-positivity Source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3662097/table/T2/ 20 HEPATITIS B 21 Temporal variation Secular trends in the United States The incidence of reported hepatitis B peaked in the mid-1980s, with about 26,000 cases reported each year. Reported cases have declined since that time, and fell below 10,000 cases for the first time in 1996. The decline in cases during the 1980s and early 1990s is generally attributed to reduction of transmission among men who have sex with men and injection-drug users as a result of HIV prevention efforts. During 1990–2004, incidence of acute hepatitis B in the United States declined 75%. The greatest decline (94%) occurred among children and adolescents, coincident with an increase in hepatitis B vaccine coverage. A total of 3,405 cases of hepatitis B were reported in 2009. Hepatitis B – United States, 1978-2009 Source: http://www.cdc.gov/vaccines/pubs/pinkbook/hepb.html HEPATITIS B 22 Reported cases of HBV infection represent only a fraction of cases that actually occur. In 2001, a total of 7,844 cases of acute hepatitis B were reported to CDC. Based on these reports, CDC estimates that 22,000 acute cases of hepatitis B resulted from an estimated 78,000 new infections. An estimated 700,000 to 1.4 million persons in the United States are chronically infected with HBV, and an additional 5,000–8,000 persons become chronically infected each year. Before routine childhood hepatitis B vaccination was recommended, more than 80% of acute HBV infections occurred among adults. Adolescents accounted for approximately 8% of infections, and children and infants infected through perinatal transmission accounted for approximately 4% each. Perinatal transmission accounted for a disproportionate 24% of chronic infections. In the United States in 2005, the highest incidence of acute hepatitis B was among adults aged 25–45 years. Approximately 79% of persons with newly acquired hepatitis B infection are known to engage in high-risk sexual activity or injection-drug use. Other known exposures (i.e., occupational, household, travel, and healthcare-related) together account for 5% of new infections. Approximately 16% of persons deny a specific risk factor for infection. Cyclic and Seasonal Hepatitis B does not have cyclic fluctuations and seasonal trends, because this is an infection disease that is related to a human behavior, style of life and is an infectious disease that in the majority of cases is sexually transmitted. Epidemic HEPATITIS B 23 The prevalence of chronic hepatitis B infection is variable throughout the world, ranging from < 1% in areas of low endemism up to 30% in highly endemic areas. There has been an overall decline in the prevalence of the disease due to global infant and childhood vaccination programs, post-exposure prophylaxis and anti-viral therapy. As a result of global vaccination programs, many countries in Asia that once had high rates of HBV infection are now classified as intermediate endemic areas. The variations of hepatitis b in the distributional geography are regulated for the implementation of vaccination programs in each country. However, vaccination programs have still not been implemented in all countries, thereby maintaining reservoirs of infection and continued HBV transmission, especially in countries of high endemicity. Some examples of this variation in countries in the world are: The highest incidence of HBV in Europe is in the 25 to 44-year old age group, followed by the 15 to 24 year-old age group. The infection is more common in males (1.33 cases per 100,000) than females (0. 58 cases per 100,000). In countries with intermediate to high endemicity, childhood transmission within infected households are the most common routes of infection, whereas in low endemic areas, intravenous drug use and sexual activity are the predominant. For example, in the Netherlands where the prevalence rate is low, sexual transmission is the most frequent mode of infection. Additionally, after the introduction of dry heat sterilization in the 1970s which was insufficient to eliminate HBV, multiple studies in Poland showed that nosocomial infections from blood transfusions and medical procedures accounted for up to 60% of HBV infections in adults and 80% in children. Today, strict blood screening, vaccination HEPATITIS B 24 and improved sanitation practices have led to a declining trend of HBV prevalence in most countries. Throughout the Eastern Mediterranean region, transmission occurs through childhood and adulthood. Risk factors associated with infection include residence in a rural area, overcrowding, poor sanitary conditions, parenteral drug use, and exposure to blood products, medical procedures, ear piercing and scarification. Perinatal transmission is widely thought to be the reason for high endemicity in the Western Pacific region. In Taiwan, an overall 30% of HBsAg positive women of childbearing age had positive HBeAg, indicative of active replication. However, a study from China showed that childhood horizontal transmission may be the most important mode of infection, accounting for up to 80% of all HBV infection. Furthermore, a study of rural sites in the Philippines suggests variable patterns of transmission in other parts of Asia. In some villages in the Phillipines, HBsAg seroprevalence peaks in the 2 to 9-year old age group, while other villages have relatively consistent seroprevalence peaking in the 30 to 49-year old age groups. Regardless of the mode of infection, the Western Pacific region continues to be a highly endemic region of HBV infection with a need for continued prevention and treatment strategies. Outbreaks of Hepatitis B in US Outbreaks of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection reported in the United States during 2008-2013. Because of the long incubation period (up to 6 months) and typically asymptomatic course of acute hepatitis B and C infection, it is likely that only a fraction of such outbreaks that occurred have been detected, and reporting of outbreaks detected and HEPATITIS B 25 investigated by state and local health departments is not required. Therefore, the numbers reported here may greatly underestimate the number of outbreak-associated cases and the number of at-risk persons notified for screening. 38 outbreaks of viral hepatitis related to healthcare reported to CDC during 2008-2013; of these, 36 (94%) occurred in non-hospital settings. Hepatitis B (total 20 outbreaks, 162 outbreak-associated cases, >10,500 persons notified for screening): 15 outbreaks occurred in long-term care facilities, with at least 114 outbreak-associated cases of HBV and approximately 1,400 at- risk persons notified for screening 87% (13/15) of the outbreaks were associated with infection control breaks during assisted monitoring of blood glucose (AMBG) 5 outbreaks occurred in other settings, one each at: a free dental clinic in school gymnasium, an outpatient oncology clinic, a hospital surgery service, and two at pain remediation clinics (one outbreak of HBV and one with both HBV and HCV), with 46 outbreak-associated cases of HBV and > 8,500 persons at-risk persons notified for screening Additional characteristics that contribute to an epidemiologic description of Hepatitis B Some factor that contribute to the epidemiology description of Hepatitis B are: Persons with either acute or chronic HBV infection should be considered infectious any time that HBsAg is present in the blood. When symptoms are present in persons with HEPATITIS B 26 acute HBV infection, HBsAg can be found in blood and body fluids for 1–2 months before and after the onset of symptoms. Although HBV infection is uncommon among adults in the general population (the lifetime risk of infection is less than 20%), it is highly prevalent in certain groups. Generally, the highest risk for HBV infection is associated with lifestyles, occupations, or environments in which contact with blood from infected persons is frequent. In addition, the prevalence of HBV markers for acute or chronic infection increases with increasing number of years of high-risk behavior. For instance, an estimated 40% of injection-drug users become infected with HBV after 1 year of drug use, while more than 80% are infected after 10 years. Vaccine nonresponse to Hepatitis Be could be another factor related to the epidemiology of Hepatitis B. Several factors have been associated with nonresponse to hepatitis B vaccine. These include vaccine factors (e.g., dose, schedule, injection site) and host factors. Older age (40 years and older), male sex, obesity, smoking, and chronic illness have been independently associated with nonresponse to hepatitis B vaccine. Summarize any current hypotheses that have been proposed to explain the observed distribution According to the table social and economic distribution of Hepatitis B in Nigeria, the Bivariate analysis of socio-demographic variables as related to HBsAg sero-positivity showed that age (χ2= 29.7, df = 2, P = 0.048) and occupation (χ2 = 47.2, df = 8, P = 0.019) were statistically significant. The age group 40-60 years and artisans were significantly infected. Socio-economic variables such as sex, marital status, educational attainment and socio-economic class were not statistically significant. HEPATITIS B 27 List any principal gaps in knowledge about the distribution of the health problem. The three major risk groups: heterosexuals with contact with infected persons or multiple partners, injection-drug users, and men who have sex with men; are not reached effectively by targeted programs. Deterrents to immunization of these groups include lack of awareness of the risk of disease and its consequences, lack of effective public or private sector programs, and vaccine cost. Difficulty in gaining access to these populations is also a problem. Further, success in providing vaccine to persons in high-risk groups has been limited because of rapid acquisition of infection after beginning high-risk behaviors, low initial vaccine acceptance, and low rates of completion of vaccinations. (CDC, 2012) The decline in the rate of new HBV infections in the United States over the past two decades is encouraging, and new oral agents for treatment are in clinical trials. However, problems must be resolved before hepatitis B can be eradicated. One obstacle is the unsubstantiated fear of neurologic side effects of HBV vaccines. A recent large case-control study failed to demonstrate a connection between the recombinant vaccine and an increased risk of multiple sclerosis, which had been suggested by earlier case reports. Another obstacle is the current failure to offer hepatitis vaccination in STD clinics and correctional facilities, as well as to other high-risk groups. HEPATITIS B 28 Further Epidemiological Research The greatest need for research is in accurate measurement of prevalence of HBV infection in the United States. The current estimates are primarily based upon the NHANES survey, which does not address the population groups in which HBV is prevalent. Data from other ad-hoc screening surveys are limited, because they were derived from individuals who participated in the surveys voluntarily and it is difficult to gauge whether the data are generalizable. NHANES-type surveys that employ probabilistic sampling of the target population (e.g., Asian immigrants) that will generate data that are generalizable to the population will be very helpful not only to assess the current burden of HBV infection in the population but also to monitor the impact of public health interventions. (CDC, 2014) The data that are obtained from the death registries and hospital discharge summaries, lack the clinical details that are necessary for complete understanding of what is going on with HBV infection in the population, such as impact of wide-spread application of antiviral therapy. Large cohort studies should be done that include representative samples of the population and incorporate detailed clinical information may complement the information from public health sources. HEPATITIS B 29 References Akbat, N., Basuki, M., Garabrant, H.D., Dulaiman, A. & Noer, S.H. (n.d.). Etnicity, Socioeconomic status, Transfusions and Risk of Hepatitis B and Hepatitis C Infecction. Retrieved January 15, 2015, from http://deepblue.lib.umich.edu/bitstream/handle /2027.42/72591/j.1440-1746.1997.tb00365.x.pdf?sequence=1 Center for Disease Control and Prevention (2015). Vaccines and Immunizations. Retrieved on January 19, 2015 from http://www.cdc.gov/vaccines/pubs/pinkbook/hepb.html Center for Disease Control and Prevention (2015). National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention. Retrieved on January 19, 2015 from http://www.cdc.gov/nchhstp/ Custer, B., Sullivan, S. D. P., Hazlet, T. K.,Iloeje, U., Veenstra, D. L., Kowdley, K.V. ( 2004). Global Epidemiology of Hepatitis B Virus. Retrieved on January 15, 2015, from http://journals.lww.com/jcge/Abstract/2004/11003/Global_Epidemiology_of_Hepatitis_B_Virus. 8.aspx Pascal, G.U. & Ikwudinma, A.O. (2013). 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