Characterization of HBV Among HBV/HIV-1 Co-Infected Injecting Drug Users from Mombasa, Kenya.

BACKGROUND: Hepatitis B (HBV) and Human Immunodeficiency virus (HIV) are both bloodborne viruses. Markers of either active or past HBV infection are present in many HIV infected patients. Worldwide, HBV prevalence varies geographically and endemicity is classified as low (<2%) or high (>8%). Genotypically, prevalence varies among different populations, with genotype A having a wide distribution. In Kenya, the prevalence of HIV-1/HBV co-infection ranges from 6-53% depending on the sub-population, with genotype A as the most common. OBJECTIVE: To determine the prevalence and characterize HBV in HBV/HIV co-infected injecting drug users (IDUs) from Mombasa, Kenya. METHODS: Blood samples were collected from HIV-infected IDUs in Mombasa, Kenya. Hepatitis B surface antigen (HBsAg) was tested by enzyme immunoassay (EIA). HBV DNA was extracted by SMITEST R&D kit. Polymerase chain reaction (PCR) was done; followed by population sequencing of HBV preS, core and full genome using specific primers. Analysis was done phylogenetically with reference sequences from the Genbank. RESULTS: Seventy two HIV-positive samples were collected from IDUs in Mombasa in February and March 2010. Of these, 10 (13.89%) were HBsAg-positive by EIA. Nine of the 10 samples (12.5%) were PCR positive for HBV in the preS region; from these, four HBV full length sequences were obtained. Phylogenetic analysis showed that all belonged to genotype A1. CONCLUSION: The prevalence of HBV co-infection among HIV-infected IDUs in Mombasa, Kenya was 12.5%. Phylogenetically, sequences obtained from this study showed clusters that were distinct from reported Kenyan reference sequences from the Genbank. The findings point to an existence of a transmission network among IDUs in Mombasa. This further suggests that HBV genotypes in Kenya may be regionally diverse.

Update on HIV-1 acquired and transmitted drug resistance in Africa.

The last ten years have witnessed a significant scale-up and access to antiretroviral therapy in Africa, which has improved patient quality of life and survival. One major challenge associated with increased access to antiretroviral therapy is the development of antiretroviral resistance due to inconsistent drug supply and/or poor patient adherence. We review the current state of both acquired and transmitted drug resistance in Africa over the past ten years (2001-2011) to identify drug resistance associated with the different drug regimens used on the continent and to help guide affordable strategies for drug resistance surveillance. A total of 161 references (153 articles, six reports and two conference abstracts) were reviewed. Antiretroviral resistance data was available for 40 of 53 African countries. A total of 5,541 adult patients from 99 studies in Africa were included in this analysis. The pooled prevalence of drug resistance mutations in Africa was 10.6%, and Central Africa had the highest prevalence of 54.9%. The highest prevalence of nucleoside reverse transcriptase inhibitor mutations was in the west (55.3%) and central (54.8%) areas; nonnucleoside reverse transcriptase inhibitor mutations were highest in East Africa (57.0%) and protease inhibitors mutations highest in Southern Africa (16.3%). The major nucleoside reverse transcriptase inhibitor mutation in all four African regions was M184V. Major nonnucleoside reverse transcriptase inhibitor as well as protease inhibitor mutations varied by region. The prevalence of drug resistance has remained low in several African countries although the emergence of drug resistance mutations varied across countries. Continued surveillance of antiretroviral therapy resistance remains crucial in gauging the effectiveness of country antiretroviral therapy programs and strategizing on effective and affordable strategies for successful treatment.

HIV-1 drug resistance-associated mutations among HIV-1 infected drug-naïve antenatal clinic attendees in rural Kenya.

BACKGROUND: Access to antiretroviral therapy (ART) has increased dramatically in Sub-Saharan Africa. In Kenya, 560,000 people had access to ART by the end of 2011. This scaling up of ART has raised challenges to the Kenyan health system due to emergence of drug resistant viruses among those on treatment and possible onward transmission. To counter this, and come up with an effective treatment strategy, it has become vital to determine baseline mutations associated with drug resistance among the circulating strains of HIV-1 in Kenya. METHODS: The prevalence of mutations associated with drug resistance in HIV-1 protease (PR) and reverse transcriptase (RT) regions from 188 HIV-1 infected treatment-naïve pregnant women was investigated in Kapsabet, Nandi Hills and Kitale district hospitals of Kenya. Blood samples were collected between April 2005 and June 2006. The HIV-1 pol gene was amplified using primers for HIV-1 PR and RT and sequenced using the BigDye chemistry. The mutations were analyzed based on the IAS algorithm as well as the Stanford University HIV Drug Resistance Database. RESULTS: Based on the PR and RT sequences, HIV-1 subtypes A1 (n=117, 62.2%), A2 (n=2, 1.1%), D (n=27, 14.4%), C (n=13, 6.9%), G (n=3, 1.6%), and possible recombinants (n=26, 13.8%) were detected. Mutations associated with nucleoside reverse transcriptase inhibitors (NRTI) and non-nucleoside RTI (NNRTI)-resistance were detected in 1.6% (3 of 188) and 1.1% (2 of 188), respectively. Mutations associated with PI resistance were detected in 0.5% (1 of 188) of the study population. CONCLUSION: The prevalence of drug resistance among drug-naïve pregnant women in rural North Rift, Kenya in 2006 was 3.2%. Major drug resistance mutations associated with PIs, NRTIs and NNRTIs do exist among treatment-naïve pregnant women in North Rift, Kenya. There is a need for consistent follow-up of drug-naïve individuals in this region to determine the impact of mutations on treatment outcomes.

Population specific reference ranges of CD3, CD4 and CD8 lymphocyte subsets among healthy Kenyans.

BACKGROUND: The enumeration of absolute CD4 counts is of primary importance for many medical conditions especially HIV infection where therapeutic initiation depends on the count. These ranges tend to vary across populations. However, these ranges have not been comprehensively established in the Kenyan population. Therefore, this study aimed at establishing the reference ranges for the CD4 and CD8 T-lymphocytes in normal healthy individuals in Kenya. METHODS: A total of 315 individuals of the ages between 16 and 60 years old, in 5 different regions of the country, were recruited into the study. They were screened for diseases that potentially cause lymphocyte homeostasis perturbation. CD4/CD8 Counts were performed by use of a FACSCalibur flow cytometer (Becton-Dickinson, NJ) equipped with automated acquisition and analysis software. Results were analysed according to age, sex and region. RESULTS: Results were presented as means and ranges (in parenthesis) generated non parametrically as 2.5 and 97.5 percentiles as follows; In general population; CD3 1655 (614-2685 cells/µL ), CD4 920 (343-1493 cells/µL), and CD8 646 (187-1139 cells/µL), while according to sex, females; CD3 1787 (697-2841 cells/µL), CD4 1010 (422-1572 cells/µL), CD8 659 (187-1180 cells/µL); males; CD3 1610 (581-2641 cells/µL), CD4 889(320-1459 cells/µL) and CD8 644 (185-1140 cells/µL). The general reference ranges for CD4/CD8 ratios were as follows; general population 1.57(0.50-2.74), males 1.51(0.49-2.64) and females 1.69(0.55-2.95). CONCLUSION: The lymphocyte reference ranges for the Kenyan population are fairly comparable to those established in other African populations. The ranges also differ appreciably from those established in Germany, Italy and Switzerland. Furthermore, the study reported significant differences in the ranges of different population clusters within Kenya, as well us between males and females.

Diversity of HIV type 1 and drug resistance mutations among injecting drug users in Kenya.

Drug use in Kenya dates back to the precolonial period but research among drug users in relation to human immunodeficiency virus (HIV)-associated risk and intervention strategies has been low. To evaluate HIV-1 diversity and drug resistance among injecting drug users (IDUs), a cross-sectional study involving 58 patients was carried out in Mombasa between February and March 2010. HIV-1 RNA was extracted from plasma and polymerase chain reaction using specific primers for HIV-1 reverse transcriptase was done. Population sequencing was done and subtypes were determined phylogenetically. The prevalent HIV-1 subtypes were A1 (52/58), D (5/58), and C (2/58). The prevalence of drug resistance was 13.8% (8/58) with detection of nucleoside reverse transcriptase inhibitor (NRTI) mutations, T215F (n=5), K219Q (n=3), M184V (n=1), and nonnucleoside RTI mutation, K103N (n=1). Antiretroviral therapy (ART) and its monitoring among infected Kenyan IDUs is feasible. Policymakers and service providers in HIV prevention initiatives should improve service delivery so as to measure ART coverage among IDUs to prevent further transmission of drug-resistant variants.

Update on HIV-1 diversity in Africa: a decade in review.

BACKGROUND: HIV-1 strains have diversified extensively through mutation and recombination since their initial transmission to human beings many decades ago in Central Africa in the first part of the 20th Century (between 1915 and 1941). The upward trend in global HIV-1 diversity has continued unabated, with newer groups, subtypes, and unique and circulating recombinants increasingly being reported, especially in Africa. OBJECTIVE: In this review, we focus on the extensive diversity of HIV-1 over a decade (2000-2011), in 51 countries of the three African geographic regions (eastern and southern, western and central, and northern Africa) as per the WHO/UNAIDS 2010 classification. METHODOLOGY: References for this review were identified through searches of PubMed, conference abstracts, Google Scholar, and Springer Online Archives Collection. We retrieved 273 citations, of which 200 reported HIV-1 diversity from Africa from January, 2000 to August, 2011. Articles resulting from these searches and relevant references cited in those articles were reviewed. Articles published in English and French were included. FINDINGS: There has been a high diversity of HIV-1 in its epicenter, west-central Africa. A few subtypes, namely, A (A1, A2, A3, A4, A5), C, CRF02_AG, and D accounted for about 85% of new infections. Subtype A and D have been stable in East Africa; C in southern Africa; A, G, CRF02_AG, and CRF06_cpx in western Africa; and subtype B and CRF02_AG in northern Africa. Recently a new putative group, designated P, was reported to be found in two Cameroonians. CONCLUSION: The regional distributions of individual subtypes and recombinants are broadly stable, although unique/circulating recombinant forms may play an increasing role in the HIV pandemic. Understanding the kinetics and directions of this continuing adaptation and its impact on viral fitness, immunogenicity, and pathogenicity are crucial to the successful design of effective HIV vaccines. There is need for regular monitoring and review updates, such as the one presented here, to assist countries to plan and anticipate complex forms that may be introduced with time.

HIV type 1 subtype surveillance in central Kenya.

Human immunodeficiency virus 1 (HIV-1) infection is characterized by genetic diversity such that specific viral subtypes are predominant in specific geographic areas. To determine circulating subtypes of HIV-1 in different parts of central Kenya, a cross-sectional study was carried out on HIV-1-positive blood samples collected from consenting individuals in eight hospitals of Kenya's central province. Proviral DNA was extracted from peripheral blood mononuclear cells. Polymerase chain reaction and direct sequencing using primers generated from a highly conserved region of HIV-1 env gp41 were carried out. Ninety-six samples were successfully amplified and sequenced. Analysis of the sequences showed that a majority of them belonged to subtype A1 (67/96, 69.8%), followed by subtypes D (18, 18.7%) and C (11/96, 11.5%). Consistent with findings in other parts of Kenya, HIV-1 subtype A1 was the most dominant virus in circulation. Continued surveillance of circulating subtypes of HIV-1 in Kenya is important in determining the evolution of the HIV/AIDS epidemic in Kenya.

HIV type 1 gag genetic diversity among antenatal clinic attendees in North Rift Valley, Kenya.

HIV genetic recombination and high mutation rate increase diversity allowing it to escape from host immune response or antiretroviral drugs. This diversity has enabled specific viral subtypes to be predominant in specific regions. To determine HIV-1 subtypes among seropositive antenatal clinic attendees in Kenya's North Rift Valley, a cross-sectional study was carried out on 116 HIV-1-positive blood samples. Proviral DNA was extracted from peripheral blood mononuclear cells by DNAzol lysis and ethanol precipitation. Polymerase chain reactions using specific primers for HIV-1 gag and population sequencing on resulting amplicons were carried out. Phylogenetic analysis revealed that 81 (70%) were subtype A1, 13 (11%) subtype D, 8 (7%) subtype C, 3 (3%) subtype A2, 1 (1%) subtype G, and 10 showed possible recombinants: 5 (4%) subtype A1D, 4 (3%) subtype A1C, and 1 (1%) subtype A2C. These data support the need to establish circulating subtypes for better evaluation of effective HIV diagnostic and treatment options in Kenya.

Efficient monitoring of HIV-1 vertically infected children in Kenya on first-line antiretroviral therapy.

BACKGROUND: Worldwide access to antiretroviral therapy (ART) in low- and middle-income countries has significantly increased. Although this presents better treatment options for HIV-infected individuals, the challenge of monitoring ART in these settings still remains. OBJECTIVE: To investigate efficient and cost-effective criteria for assessing ART failure among HIV-1-infected children on first-line ART in resource-limited settings. STUDY DESIGN: Retrospective analysis of 75 HIV-1 vertically infected Kenyan children with a follow-up period of 24 months after initiating ART. Plasma viral load, peripheral CD4(+)T-cell counts and HIV-1 drug-resistance mutations were monitored biannually. RESULTS: Plasma viral load (VL) was suppressed to undetectable level or more than 1.5 log(10) from baseline levels in 53 (70.7%) children within 24 months. VL in the remaining 22 (29.3%) children was not suppressed significantly. Of the 22 children, 21 were infected with HIV-1 strains that developed drug-resistance mutations; 9 within 12 months and 12 between 12 and 24 months. Among the 53 who were successfully treated, VL was suppressed in 33 within 12 months and in 20 between 12 and 24 months. There was no significant difference in VL at baseline and the change of CD4(+)T-cell counts after initiating ART between those treated successfully and the failure groups. CONCLUSION: After initiating ART, children may require longer times to achieve complete viral suppression. Plasma viral load testing 24 months after initiating ART could be used to differentiate ART failures among HIV-1 vertically infected children in resource-limited settings. Additionally, drug resistance testing, if affordable, would be helpful in identifying those failing therapy and in choosing second-line regimens.

Genetic characterization of HIV type 1 among patients with suspected immune reconstitution inflammatory syndrome after initiation of antiretroviral therapy in Kenya.

Antiretroviral therapy (ART) has improved the survival of HIV patients but is also associated with unique manifestations of disease in some subjects during the initial months of therapy. Immune reconstitution inflammatory syndrome (IRIS) is a disorder among individuals starting ART, with no evidence-based treatment and management guidelines. We characterized HIV-1 and determined drug resistance among 14 Kenyan patients with suspected IRIS after ART initiation in 2005. Polymerase chain reaction, sequencing, and phylogenetic analysis of viral pol and env showed the following HIV-1 subtypes: A1/A1/A1 (pol-RT/gp41/C2V3), 5; A1/C/A1, 1; A1/D/A1, 2; D/A1/A1, 1; D/C/A1, 1; D/D/A1, 2; D/D/D, 1; and D/A1/A2, 1. Three patients had viruses with major drug resistance-associated mutations. These included nucleoside reverse transcriptase inhibitor (RTI) mutations: M41L, K65R, D67N, K70R, M184V, and K219Q, and nonnucleoside RTI mutations: K101P, L100I, K103N, and Y181C. Twelve patients harbored viruses that are predicted to use chemokine coreceptor 5 (CCR5) whereas two had variant viruses predicted to use the CXCR4 coreceptor. Drug resistance may not be the only cause of ART adverse events. HIV-1 characterization would be important before and during HIV therapy to avoid treatment failure.

HIV-1 subtype and viral tropism determination for evaluating antiretroviral therapy options: an analysis of archived Kenyan blood samples.

BACKGROUND: Infection with HIV-1 is characterized by genetic diversity such that specific viral subtypes are predominant in specific geographical areas. The genetic variation in HIV-1 pol and env genes is responsible for rapid development of resistance to current drugs. This variation has influenced disease progression among the infected and necessitated the search for alternative drugs with novel targets. Though successfully used in developed countries, these novel drugs are still limited in resource-poor countries. The aim of this study was to determine HIV-1 subtypes, recombination, dual infections and viral tropism of HIV-1 among Kenyan patients prior to widespread use of antiretroviral drugs. METHODS: Remnant blood samples from consenting sexually transmitted infection (STI) patients in Nairobi were collected between February and May 2001 and stored. Polymerase chain reaction and cloning of portions of HIV-1 gag, pol and env genes was carried out followed by automated DNA sequencing. RESULTS: Twenty HIV-1 positive samples (from 11 females and 9 males) were analyzed. The average age of males (32.5 years) and females (26.5 years) was significantly different (p value < 0.0001). Phylogenetic analysis revealed that 90% (18/20) were concordant HIV-1 subtypes: 12 were subtype A1; 2, A2; 3, D and 1, C. Two samples (10%) were discordant showing different subtypes in the three regions. Of 19 samples checked for co-receptor usage, 14 (73.7%) were chemokine co-receptor 5 (CCR5) variants while three (15.8%) were CXCR4 variants. Two had dual/mixed co-receptor use with X4 variants being minor population. CONCLUSION: HIV-1 subtype A accounted for majority of the infections. Though perceived to be a high risk population, the prevalence of recombination in this sample was low with no dual infections detected. Genotypic co-receptor analysis showed that most patients harbored viruses that are predicted to use CCR5.

HIV type 1 subtype diversity and drug resistance among HIV type 1-infected Kenyan patients initiating antiretroviral therapy.

The treatment of HIV-1 infection with antiretroviral drugs has greatly improved the survival of those who are infected. However, HIV-1 diversity and drug resistance are major challenges in patient management, especially in resource-poor countries. To evaluate HIV-1 genetic diversity and drug resistance-associated mutations among drug-naive patients in Kenya prior to antiretroviral therapy (ART), a genetic analysis of HIV-1 pol-RT and env-gp41 was performed on samples collected from 53 (18 males and 35 females) consenting patients between April and June 2005. The average age, baseline CD4(+) T cell counts, and viral loads were 38 (range, 24-62) years, 475 (range, 203-799) cells/mm(3), and 4.7 (range, 3.4-5.9) log(10) copies/ml, respectively. Phylogenetic analysis revealed that 40 samples (75.5%) were concordant subtypes for the two genes and 13 (24.5%) were discordant, suggesting possible recombination and/or dual infections. Prevalent subtypes included A1/A1(pol-RT/env-gp41), 31 (58.5%); D/D, 9 (16.9%); A1/C, 2 (3.8%); A1/D, 4 (7.5%); G/A1, 2 (3.8%); A1/A2, 1 (1.9%); C/A1, 2 (3.8%); D/A1, 1(1.9%); and D/A2, 1 (1.9%). Major reverse transcriptase inhibitor (RTI) resistance-associated mutations were found in four patients (7.5%). Of these patients, three had nucleoside RTI resistance mutations, such as M184V, K65R, D67N, K70R, and K219Q. Nonnucleoside RTI resistance-associated mutations K103N and Y181C were detected in three patients and one patient, respectively. Multiple drug resistance mutations were observed in this drug-naive population. With increasing numbers of patients that require treatment and the rapid upscaling of ART in Kenya, HIV-1 drug resistance testing is recommended before starting treatment in order to achieve better clinical outcomes.

Genetic diversity of HIV type 1 along the coastal strip of Kenya.

A study on the genetic diversity of HIV-1 subtypes present along the coastal strip of Kenya, i.e., Kilifi, Mombasa, Msambweni, and Malindi districts, was carried out. DNA sequences for regions encoding a portion of the env-gp41 region of the virus were generated by PCR and sequenced directly. Eighty six samples that were successfully sequenced were analyzed. From the analysis, 86% (74) were subtype A1, 5% (4) were subtype C, 8% (7) were subtype D, and 1% (1) was subtype G. This study shows that HIV-1 subtype A1 is the most dominant subtype in circulation in this region.

The changing trend of HIV type 1 subtypes in Nairobi.

Monitoring the distribution of HIV-1 subtypes and recombinants among infected individuals has become a priority in HIV therapy. A laboratory analysis of samples collected from HIV-positive patients attending an STI clinic in Nairobi was done between March and May 2004. PCR was carried out on pol (intergrase) and env (C2V3) regions and resulting data on the 54 samples successfully analyzed revealed the following as circulating subtypes: 35/54(65%) were A1/A1, 5/54(9%) were A/C, 4/54 (7%) were A1/D, 1/54 (2%) was C/D, 1/54 (2%) was D/D, 1/54 (2%) was A1/A2, 1/54 (2%)was G/G, 1/54 (2%) was A2/D, 1/54 (2%) was C/C, and 4/54 (7%) were CRF02_ AG. The results show an increase in HIV-1 recombinants with the emergence of A1/A2 and an increase in CRF02_AG recombinants. Subtype diversity in the advent of ARV use will impact negatively on treatment outcomes. As such, increased viral evolution and recombination will call for continuous evaluation of available anti-HIV regimens for better management of those infected with HIV-1.

Changes in the HIV type 1 envelope gene from non-subtype B HIV type 1-infected children in Kenya.

A switch of coreceptor usage from CCR5 to CXCR4 occurs in about half of HIV-1-infected individuals in the natural course of infection. To investigate whether antiretroviral therapy (ART) enhances the coreceptor switch of HIV-1, we genotypically analyzed the env-V3 amino acid sequences from 81 HIV-1-infected children in Kenya whose plasma samples were obtained between 2000 and 2007. Of 41 children on ART, 35 had HIV-1 using CCR5 as a coreceptor at baseline. In 7 (20%) of them HIV-1 switched the coreceptor usage during the follow-up period. The mean duration of ART to the time of coreceptor switch was 2.6 years (range: 0.5-5.2). Of the remaining 40 children without ART, 32 had HIV-1 using CCR5 as a coreceptor at baseline and in 3 (9.4%) HIV-1 switched the coreceptor usage. The mean age of the children with HIV-1 coreceptor switch with and without ART was 7.3 and 9.7 years, respectively. The difference in the rate and age of coreceptor switch between treated and untreated children was not significant (p = 0.38 and 0.31, respectively). Of the HIV-1-infected children, 10 started ART by the age of 5 years (rapid progressors) and 23 did not need ART by the age of 10 years (slow progressors). The rate of coreceptor switch was strongly higher in rapid progressors (40%) than slow progressors (8.7%) (p = 0.053). These results suggest that switching of coreceptor usage from CCR5 to CXCR4 among HIV-1-infected children is not influenced by ART, but by factors responsible for rapid disease progression.

HIV type 1 genetic diversity in Moyale, Mandera, and Turkana based on env-C2-V3 sequences.

The genetic diversity of HIV-1 subtypes circulating in three districts of northern Kenya, i.e., Turkana, Mandera, and Moyale, was studied. DNA sequences encoding a portion of the env-C2-V3 region of the virus were amplified by PCR and sequenced directly. One hundred and fifty-nine samples were successfully sequenced in the env-C2-V3 region and analyzed. From the analysis, 57% were subtype A1, 27% were subtype C, 9% were subtype D, and the remaining 7% were unclassified. This study showed that HIV-1 subtype A1 was the dominant subtype in circulation in this region, though there was a significant percentage of HIV-1 subtype C in circulation there.

HIV type 1 subtypes among STI patients in Nairobi: a genotypic study based on partial pol gene sequencing.

Circulating strains of human immunodeficiency virus (HIV) exhibit an extraordinary degree of genetic diversity and have been classified on the basis of relationships into distinct lineages called groups, types, subtypes, and subsubtypes. Sexually transmitted infections (STIs) are known to be a risk factor for HIV infection. To establish HIV-1 subtype diversity among STI patients in Nairobi, 140 samples were collected and partial pol gene sequencing done. From the analysis it was established that subtype A1 was the major subtype (64%) followed by D (17%), C (9%), G (1%), and recombinants AD (4%), AC (3%), CRF02()AG (1%), and CRF16()A2D (1%). These results suggest that the HIV-1 epidemic may be evolving toward more virulent and complex subtypes through transmission of complex recombinants due to viral mixing. Any use of ARVs may therefore require initial testing for de novo resistance before commencement of treatment and/or management.

HIV type 1 subtypes in circulation in northern Kenya.

The genetic subtypes of HIV-1 circulating in northern Kenya have not been characterized. Here we report the partial sequencing and analysis of samples collected in the years 2003 and 2004 from 72 HIV-1-positive patients in northern Kenya, which borders Ethiopia, Somalia, and Sudan. From the analysis of partial env sequences, it was determined that 50% were subtype A, 39% subtype C, and 11% subtype D. This shows that in the northern border region of Kenya subtypes A and C are the dominant HIV-1 subtypes in circulation. Ethiopia is dominated mainly by HIV-1 subtype C, which incidentally is the dominant subtype in the town of Moyale, which borders Ethiopia. These results show that cross-border movements play an important role in the circulation of subtypes in Northern Kenya.

Identification of env CRF-10 among HIV variants circulating in rural western Kenya.

As part of a program to determine the genetic diversity of human immunodeficiency virus in rural Kenya, we carried out a molecular analysis of the C2-V3 region of HIV-infected blood samples obtained from 30 antenatal clinic attendees of seven health centers in western Kenya. Direct sequencing was carried out on the envelope C2-V3 region of proviral DNA. On phylogenetic analysis with reference strains, 20 were subtype Al, 2 were subtype D, 1 was subtype C, 1 was subtype G, 1 was CRF-10, 2A/D, 2A/C, and 2 were unclassified. The presence of CRF-10 and the great variety of subtypes and recombinants in such a limited sample size suggest that western Kenya may be a potential hotspot for HIV recombination in the country.