Prevalence of hepatitis C virus and its genotypes among a cohort of drug users in Kenya.

BACKGROUND: Prevalence of hepatitis C virus and that of its main genotypes varies between the worlds geographic regions. The risk factors for infection with HCV include blood transfusion, tattoing and injecting drug use. OBJECTIVES: To examine the prevalence of HCV and determine its main genotypes among a cohort of drug users in Kenya. DESIGN: A laboratory based study. SETTING: Hepatitis research laboratory in the Centre for Virus Research at the Kenya Medical Research Institute, Nairobi. SUBJECTS: Three hundred and fourteen male and 19 female intravenous and non-intravenous drug users aged between 15-55 years. RESULTS: Seventy four (22.2%) out of 333 samples tested positive for anti-HCV. Sixty nine out of the 74 serum samples were assayed for HCV RNA and 38 (55.5%) were positive. The RNA positive samples were further subjected to sequencing and 19 (73%) of the samples were classified as genotype 1a, while seven (27%) samples were classified as genotype 4. Genotypes 2, 3, 5 and 6 were not identified in this study. CONCLUSIONS: These results demonstrate a high HCV infection prevalence among this cohort of drug users (22.2%) as compared to that of the general population, which is estimated to be 0.2-0.9%. The study also confirms the presence of at least two major genotypes among Kenyan drug users (genotypes 1 and 4).

KEMRI Hep-cell II hepatitis B surface antigen screening kit.

BACKGROUND: Kenya is a high hepatitis B virus (HBV) endemic zone. Prevention of HBV transmission by transfusing safe blood is necessary. Kits for screening hepatitis B surface antigen (HBsAg) are usually imported and are expensive. Hence it has been difficult to screen donated and patient blood samples all over Kenya. OBJECTIVE: To produce a HBsAg screening kit locally in order to be able to screen donated and patient blood samples all over Kenya. DESIGN: A laboratory based study. SETTING: Centre for Virus Research (CVR), Kenya Medical Research Institute (KEMRI), Nairobi. METHOD: Purified HBsAg from plasma of carriers obtained from National Public Health Laboratories Services (NPHLS) was used to minimise guinea pigs to produce antihepatitis B (anti HBs) antibody. The anti HBs was then used to sensitise sheep red blood cells (SRBC). The final product was freeze dried (lyophilised) and its sensitivity and specificity was compared with other commercial kits. RESULTS: The sensitivity and specificity of KEMRI Hep-cell II was found to be 98% and 99%, respectively. The kit was found to be stable and potent for one year whether kept 4 degrees C, 37 degrees C or room temperature. CONCLUSION: KEMRI Hep-cell II was successfully produced locally. The sensitivity and specificity were comparable to other commercial kits. The kit was stable and potent for one year between temperature of 4 degrees C and 37 degrees C. The kit required only simple apparatus to carry out the test hence it can be used anywhere in Kenya. It was also cheap and affordable.

PIP: Kenya is a high hepatitis B virus endemic zone, and prevention of viral transmission by transfusing safe blood is necessary. However, kits for screening hepatitis B surface antigen (HBsAg) are usually imported and are expensive; hence, it has been difficult to screen donated and patient blood samples all over the country. This laboratory-based study, conducted at the Kenya Medical Research Institute (KEMRI), produced a HBsAg screening kit locally in order to be able to screen donated and patient blood samples throughout Kenya. Purified HBsAg from plasma carriers obtained from the National Public Health Laboratories Services was used to induce guinea pigs to produce anti-hepatitis B antibody (anti-HBs). The anti-HBs was then used to sensitize sheep red blood cells. The final product was freeze dried (lyophilized) and its sensitivity and specificity was compared with other commercial kits. The KEMRI Hep-cell II had 98% and 99% sensitivity and specificity, respectively, in comparison with other commercial kits. The kit was found to be stable and potent for 1 year at temperatures of 4 degrees Celsius, 37 degrees Celsius, or at room temperature. The KEMRI Hep-cell II kit is cheap and affordable and requires a simple apparatus to carry out the test; hence, it can be used anywhere in Kenya.

Human plasma derived hepatitis B vaccine: Kenyan experience.

OBJECTIVE: To determine the efficacy and safety of hepaccine B. DESIGN: Vaccination on first-come-first-served basis. SETTING: Kenya Medical Research Institute (KEMRI) staff and families at Nairobi, Kenya. PARTICIPANTS: A total of 107 vaccinees aged 0-10 years and 10 years and above. MAIN OUTCOME: Antibody to hepatitis B surface antigen (anti HBs) checked one month after the third dose of the vaccine. RESULTS: Ninety seven per cent of the vaccinees developed antiHBs. Side effects were few in the form of soreness at site of injection and headache. CONCLUSION: Hepaccine B produced good immune response in vaccinees with minimal side effects.