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HOW TO DIAGONISE HIV INFECTION Appelles Ohanga-Too HIV/AIDS prevention and management Spring 2015 Diaconia University of Applied Sciences Masters-Degree Programme in global healthcare According to WHO webpage human immunodeficiency virus (HIV) is a retrovirus that infects cells of the immune system, destroying or impairing their function. As the infection progresses, the immune system becomes weaker, and the person becomes more susceptible to infections and eventually the most advanced stage of HIV infection which is acquired immunodeficiency syndrome (AIDS). HIV is transmitted through unprotected sexual intercourse (anal or vaginal), transfusion of contaminated blood, sharing of contaminated needles, and between a mother and her infant during pregnancy, childbirth and breastfeeding. Justine et al 2001 states that symptoms play a central role in the patient’s experience of disease. They are the primary reason a patient seeks care, and a determinant of the patient’s perceived health related quality of life. According to WHO symptoms of HIV vary depending on the stage of infection. Though people living with HIV tend to be most infectious in the first few months, many are unaware of their status until later stages. The first few weeks after initial infection, individuals may experience no symptoms or an influenza-like illness including fever, headache, rash or sore throat. As the infection progressively weakens the person's immune system, the individual can develop other signs and symptoms such as swollen lymph nodes, weight loss, fever, diarrhoea and cough. Without treatment, they could also develop severe illnesses such as tuberculosis, cryptococcal meningitis, and cancers such as lymphomas and Kaposi's sarcoma, among others. HIV TESTING AND COUNCELLING (HTC) WHO webpage indicates that HIV testing and counselling (HTC) services have helped millions of people learn their HIV status, and for those testing positive, learn about options for long term care and treatment. HIV testing and counselling (HTC) services have helped millions of people learn their HIV status, and for those testing positive, learn about options for long term care and treatment. Kenya national guidelines of HIV testing and counselling is delivering HTC through voluntary counseling and testing or provider-initiated counseling and testing (PICT). (Annelies Van Rie, 2014) Also states that alternative approaches for testing include contacts of index cases, mobile testing, door-to-door testing, school-based testing can increase HIV case finding. Provider-initiated HIV testing and counselling refers to a situation in which the HTC service provider, who may be a health care worker or other type of HTC service provider, offers an HIV test to a client or patient regardless of their reason for attending the facility. Prior to receiving an HIV test, the health care provider will explain the procedure and the reasons for requesting the test to the client or patient. Upon the recommendation of the health care provider, if the client or patient agrees to learn their HIV status s/he will receive an HIV test and will be informed of their results. World Health Organization (WHO) recommends PICT for all people visiting a health facility PICT in health care facilities in high burden countries is mainly targeted at individuals presenting for antenatal, TB or STI care . (National guidelines for HIV testing and councelling in kenya, 2008) Client-initiated HTC refers to a situation whereby an individual, couple, or group actively seeks out HIV testing and counselling at a site where these services are provided and/or accessible. Previously in Kenya this took place primarily in the context of voluntary counselling and testing (VCT); however HTC may be initiated by clients in settings other than VCT sites such as health facilities, mobile sites, or in people’s homes. The clientinitiated approach to HTC requires that persons wishing to know their HIV status take it upon themselves to request an HIV test. Clients may seek HTC services to guide personal life decision making, plan for one’s future or the future of their family, and understand symptoms one is experiencing, or support personal HIV prevention efforts. Screening tests for HIV and Diagnosis According to the center of disease control (CDC), there are three types of HIV diagnostic tests: antibody tests, antigen/antibody tests, and nucleic acid (RNA) tests. Antibody tests detect antibodies, proteins that your body makes against HIV, not HIV itself. Antigen tests and RNA tests detect HIV directly. CDC continues to state that an initial HIV test will either be an antibody test or antigen/antibody test. It may involve sending blood or oral fluid to a laboratory or obtaining blood or oral fluid for a rapid test. Blood tests can detect HIV infection sooner after exposure than oral fluid tests because the level of antibody in blood is higher than it is in oral fluid. Likewise, antigen/antibody and RNA tests detect infection in blood before antibody tests. Some newer antigen/antibody lab tests can sometimes find HIV as soon as three weeks after exposure to the virus. No antigen/antibody or RNA tests are available for oral fluid. Follow-up testing is performed if the initial test result is positive. HIV tests are generally very accurate, but follow-up testing allows you and your health care provider to be sure the diagnosis is right. If your initial test is a rapid test and it is positive, you will be directed to get follow-up testing. If your initial test is a laboratory test and it is positive, the laboratory will usually conduct follow-up testing on the same blood specimen as the initial test. Follow-up tests include: antibody differentiation tests, which distinguishes HIV-1 from HIV-2 antibodies; HIV-1 nucleic acid tests, which looks for the virus RNA directly; Western blot and indirect immunofluorescence assay, which detect antibodies. Currently the most sensitive screening tests are so-called fourth-generation assays (Ag/Ab assays), which detect both HIV antibodies and p24 antigen simultaneously and thereby shorten the window period during which an individual may be infected but antibodies are not detectable. British association for sexual health and HIV guidance (2010) states that although a negative fourth-generation HIV test 4 weeks after a risk exposure is ‘very reassuring”, an additional HIV test should be offered at 3 months. In addition, patients taking 28 days post-exposure prophylaxis (PEP) following a significant risk need to wait the usual 12-week window period, as the PEP may suppress p24 antigen production. Measurement of HIV RNA (viral load) is not usually recommended as a diagnostic assay due low-level false-positive results. However it is used to monitor therapeutic response and can be useful in the diagnosis of early infection before the production of antibodies. Some of the dilemmas for screening HIV performed using serological assay is false positive serological results in HIV and also other diseases. False-positive results with enzyme immunoassays are known to occur in many diseases/situations including multiple blood transfusions, hypergammaglobulinemia, history of recent vaccination, multiple pregnancies, hemodialysis, antibodies to HLA antigens, autoantibodies associated with autoimmune diseases, and cross-reactivity with vector proteins amongst others. (Sujoy Khan, 2014) Rapid test is an immunoassay used for screening, and it produces quick results, in 30 minutes or less. Rapid tests use blood or oral fluid to look for antibodies to HIV. If an immunoassay (lab test or rapid test) is conducted during the window period (i.e., the period after exposure but before the test can find antibodies), the test may not find antibodies and may give a false-negative result. All im munoassays that are positive need a follow-up test to confirm the result. Rapid tests may be applied in the following settings: Antenatal clinics when the mother presents late. Rapid test supports decision in the use of antiretroviral therapy to prevent mother-to-child transmission of HIV. Settings where a high risk of needle-stick injury is expected. Rapid test of the source patient and victim, with informed consent, informs the decision to use prophylaxis. Outreach setting where conventional HIV testing may not reach certain vulnerable populations such as drug users, sex workers and men having sex with men. Conventional HIV care setting where there is a high defaulter rate. Instead of the traditional two sessions, only one is required for those who test negative. The test is not intended for use by the general public. It is done by medical professionals and requires the same standard as conventional HIV antibody tests. However, counselling techniques may need to be adapted depending on the settings. Home Access HIV-1 Test System is a home collection kit, which involves pricking your finger to collect a blood sample, sending the sample to a licensed laboratory, and then calling in for results as early as the next business day. This test is anonymous. If the test is positive, a follow-up test is performed right away, and the results include the follow-up test. The manufacturer provides confidential counseling and referral to treatment. The tests conducted on the blood sample collected at home find infection later after infection than most lab-based tests using blood from a vein, but earlier than tests conducted with oral fluid. Diagnosis of infection in infants requires the use of NAAT tests since antibodies detected may be of maternal origin. Using fourth-generation assays these antibodies may be detected beyond 18 months of age. DNA or RNA/viral load assay may be used. mothers is to test the infant (Catherine A Ison, 2015) Indications for a diagnostic HIV test For individual diagnosis, the standard testing algorithm is the two-step use of ELISA for screening and WB for confirmation. The requesting physician should ensure that all tests are done in a quality laboratory. An HIV diagnostic test is indicated in people at risk of the infection, including persons with: Behavioural risks of and potential exposure to HIV infection, such as injecting drug use, any form of cocaine use, male-male sex, multiple sexual partners, and commercial sex. All sex partners of persons with these risk factors are also at risk. Occupational exposure to a possibly infected source, normally referring to that in the health care setting such as after a needlestick injury. Other sexually transmitted infections (STI) - It is known that either ulcerative or nonulcerative STI facilitates HIV transmission. Clinical conditions associated with HIV infection, varying from classical AIDS-defining conditions to tuberculosis, herpes zoster in a young patient, oral thrush, unexplained fever, and lymphadenopathy. Receipt of blood or blood products between 1978 and 1985, the year when screening of donated blood and organs began in Hong Kong. (Diagnostic Laboratory Testing for HIV Infection in the United States, 2012) REFERENCES A. C. Justice, C.H. Chang, Rabeneck. L, Zackin R. ( 2001). Clinical Importance of Provider-Reported HIV Symptoms Compared With Patient-report, Volume 39(4) pp 397-408. (2008). National guidelines for HIV testing and councelling in kenya. Nairobi: Ministry of Public health and sanitation. Diagnostic Laboratory Testing for HIV Infection in the United States. (2012). United states: center for disease control (CDC). Annelies Van Rie, K. C. (2014). High Uptake of Systematic HIV Counseling and Testing and TB Symptom Screening at a Primary Care Clinic in south africa. PLOS ONE www.plosone.org. Catherine A Ison, J. T. (2015). Laboratory diagnosis of sexually transmitted infection. www.medicinejournal.co.uk. Sujoy Khan, S. S. (2014). Diagnostic dilemmas in human immunodeficiency virus testing. India: Departments of Allergy and Immunology andT ransfusión Medicine, Apollo Gleneagles Hospital,. http://www.who.int/topics/hiv_aids/en/. Accessed 9.5.2015 http://www.cdc.gov/hiv/testing/index.html. Accessed 9.5.2015