Distribution of hepatitis B virus infection in Namibia

Background. Namibia regards hepatitis B virus (HBV) infection as a public health problem and introduced hepatitis B vaccinations for infants during 2009. However, information on HBV infection in the country remains limited, and effective public health interventions may be compromised in the absence of adequate evidence-based data. Available data from the World Health Organization (WHO) estimate that 15 - 60% of the normal population in many African countries may be positive for one or more of the HBV serological markers.Objective. To investigate the distribution of HBV infection in Namibia, using available laboratory data for 2013.Methods. A cross-sectional descriptive study was conducted using pre-existing electronic laboratory data on HBV infection. The data were retrieved from the central Namibia Institute of Pathology laboratory in Windhoek during January - December 2013. Tests were done on the following three main groups: (i) pregnant women during routine antenatal care (ANC) visits; (ii) patients with HIV/AIDS during antiretroviral therapy clinic visits; and (iii) any other individual suspected of having HBV infection.Results. Of a total of 77 238 hepatitis B surface antigen test results retrieved countrywide, 9 087 (11.8%) were positive. Of the positive results, 246/9 087 (2.7%) were in children aged 0 - 14 years, with the sexes equally affected. HBV infections increased markedly, particularly among females, in the age group 15 - 39 years, reaching a peak in the age group 30 - 34 years. Routine screening of pregnant women for HBV during ANC visits was found to be systematically conducted in only two regions, Ohangwena and Khomas.Conclusions. This study showed high proportions of positive results in pregnant women, patients with HIV/AIDS and individuals suspected of having HBV infection. The Ministry of Health and Social Services and stakeholders may wish to consider improving the routine and surveillance reporting systems for viral hepatitis and uptake of screening for pregnant women in all regions, and expanding HBV screening to other population groups. Population-based or similar studies are therefore required to determine the HBV prevalence and risk factors. This will assist Namibia in developing appropriate national viral hepatitis strategies as per WHO recommendations

Measles Outbreak Reveals Measles Susceptibility among Adults in Namibia; 2009 - 2011

BACKGROUND:The World Health Organization; African Region; set the goal of achieving measles elimination by 2020. Namibia was one of seven African countries to implement an accelerated measles control strategy beginning in 1996. Following implementation of this strategy; measles incidence decreased; however; between 2009 and 2011 a major outbreak occurred in Namibia.METHODS:Measles vaccination coverage data were analysed and a descriptive epidemiological analysis of the measles outbreak was conducted using measles case-based surveillance and laboratory data.RESULTS:During 1989 - 2008; MCV1 (the first routine dose of measles vaccine) coverage increased from 56% to 73% and five supplementary immunisation activities were implemented. During the outbreak (August 2009 - February 2011); 4 605 suspected measles cases were reported; of these; 3 256 were confirmed by laboratory testing or epidemiological linkage. Opuwo; a largely rural district in north-western Namibia with nomadic populations; had the highest confirmed measles incidence (16 427 cases per million). Infants aged =11 months had the highest cumulative age-specific incidence (9 252 cases per million) and comprised 22% of all confirmed cases; however; cases occurred across a wide age range; including adults aged =30 years. Among confirmed cases; 85% were unvaccinated or had unknown vaccination history. The predominantly detected measles virus genotype was B3; circulating in concurrent outbreaks in southern Africa; and B2; previously detected in Angola.CONCLUSION:A large-scale measles outbreak with sustained transmission over 18 months occurred in Namibia; probably caused by importation. The wide age distribution of cases indicated measles-susceptible individuals accumulated over several decades prior to the start of the outbreak