Human Immunodeficiency Virus and Selected Coinfections in Kenya: An Investigation on Prevalence, Genotypes, CD4 Distribution and Testing Algorithms Among HIV Infected Individuals

Abstract

HIV and AIDS has been one of the greatest public health challenges of our times.Currently, this epidemic is being compounded by co-infections including other viral infections which share similar modes of transmission and complicated pathophysiologies. The aim of this study was to determine seroprevalence of selected HIV co-infections, identify circulating genotypes and CD4 distributon in a population of HIV infected. To inform diagnostic strategies on selected co-infections, utility of targeted test kits was also determined. Hepatitis B, Hepatitis C, Herpes simplex virus 2 and syphilis were tested in a population of 1829 HIV infected subjects from different parts of Kenya. ELISA and rapid test kits were used for serological testing while polymerase chain reaction, sequencing assays and molecular analysis tools were used to determine genotypes.The CD4 counts were determine using FacsCalibur. Data generated was analysed for serostatus, genotypes and CD4 countdistribution. Comparison of test methods was carried out to determine utility of available test kits. Seroprevalence of HBV was 29% (530), HCV 14 % (256), HSV2 47% (860) and syphilis 14% (256). In this study, 71% (1299) of the subjects (were seropositive with any of the four infections (HBV, HCV, HSV2 and syphilis) while 29% had none.Co-infections ranged from one to multiple infections with 27% of the population having 2 to 4 infections. Highest combination of infections was that of HIV, HBV and HSV (34%); HIV, HSV and syphilis (16%) and HIV, HCV and HSV (10%). Study population mean CD4 count was 382 cells/m3, the mean difference between gender was 31.79yrs for female and 32.25yrs male. Distribution of CD4 count across population groups indicated that 34% of the study population had counts below 250 cells/m3. Test algorithm for HBV indicated Determine kit as the best option for screening while for HCV SD Bioline kit had the best performance. Molecular analysis of the samples indicated HIV subtypes detected were A (70%), D (18%), G (7%), and C (5%). For HBV genotypes A (82%), C (9%), D (6%) and E (3%) were identified in the study population. Genotypes 1(86%) and 2b(14%) were detected for HCV. In conclusion; there was a higher burden of infections and molecular variants of co-infections among the HIV infected. It is recommended there is need to make testing for HBV.HCV, HSV2 and syphilis accesible in health facilities alongside that of HIV. Since 34% of individuals were categorized as having advanced HIV disease based on CD4 count, CD4 count monitoring services are necessary in this particular aspect.Monitoring of circulating genotypes is an important undertaking in order to determine trends and emergence of new ones.