Antiretroviral concentrations in breast-feeding infants of women in Botswana receiving antiretroviral treatment. (41/208)

BACKGROUND: The magnitude of infant antiretroviral (ARV) exposure from breast milk is unknown. METHODS: We measured concentrations of nevirapine, lamivudine, and zidovudine in serum and whole breast milk from human immunodeficiency virus type 1 (HIV-1)-infected women in Botswana receiving ARV treatment and serum from their uninfected, breast-feeding infants. RESULTS: Twenty mother-infant pairs were enrolled. Maternal serum concentrations of nevirapine were high (median, 9534 ng/mL at a median of 4 h after nevirapine ingestion). Median breast-milk concentrations of nevirapine, lamivudine, and zidovudine were 0.67, 3.34, and 3.21 times, respectively, those in maternal serum. The median infant serum concentration of nevirapine was 971 ng/mL, at least 40 times the 50% inhibitory concentration and similar to peak concentrations after a single 2-mg/kg dose of nevirapine. The median infant serum concentration of lamivudine was 28 ng/mL, and the median infant serum concentration of zidovudine was 123 ng/mL, but infants were also receiving zidovudine prophylaxis. CONCLUSIONS: HIV-1 inhibitory concentrations of nevirapine are achieved in breast-feeding infants of mothers receiving these ARVs, exposing infants to the potential for beneficial and adverse effects of nevirapine ingestion. Further study is needed to understand the impact of maternal ARV treatment on breast-feeding HIV-1 transmission, infant toxicity, and HIV-1 resistance mutations among infected infants.  (+info)

Prevalence of clinical isolates of Cryptococcus gattii serotype C among patients with AIDS in Sub-Saharan Africa. (42/208)

Cryptococcus gattii is a group of exogenous, neurotropic yeasts that possess the capsular serotype B or C. Isolates of serotype C are extremely rare and, until recently, were known to infect only immunocompetent individuals. We genotyped 176 isolates of Cryptococcus from patients in sub-Saharan Africa who had AIDS; 22 (13.7%) of 161 isolates from Botswana and 2 (13.3%) of 15 isolates from Malawi were C. gattii serotype C strains. All of these serotype C strains belong to the rare VGIV genotype, possess the MAT alpha mating-type allele, and exhibit little genetic diversity.  (+info)

Major histocompatibility complex class II (HLA-DRB and -DQB) allele frequencies in Botswana: association with human immunodeficiency virus type 1 infection. (43/208)

Southern Africa is facing an unprecedented public health crisis due to the high prevalence of human immunodeficiency virus type 1 (HIV-1). Vaccine development and testing efforts, mainly based on elicitation of HIV-specific T cells, are under way. To understand the role of human leukocyte antigen (HLA) class II alleles in HIV pathogenesis and to facilitate HLA-based HIV-1 vaccine design, we analyzed the frequencies of HLA class II alleles within the southern African country of Botswana. Common HLA class II alleles were identified within the Botswana population through the molecular genotyping of DRB and DQB1 loci. The DRB1 allele groups DRB1*01, DRB1*02/15, DRB1*03, DRB1*11, and DRB1*13 were encountered at frequencies above 20%. Within the DQB1 locus, DQB1*06 (47.7%) was the most common allele group, followed by DQB1*03 (39.2%) and DQB1*04 (25.8%). We found that DRB1*01 was more common in HIV-negative than in HIV-positive individuals and that those who expressed DRB1*08 had lower median viral loads. We demonstrate that the frequencies of certain HLA class II alleles in this Botswana population differ substantially from those in North American populations, including African-Americans. Common allele groups within Botswana cover large percentages of other African populations and could be targeted in regional vaccine designs.  (+info)

Changes in the etiology of sexually transmitted diseases in Botswana between 1993 and 2002: implications for the clinical management of genital ulcer disease. (44/208)

BACKGROUND: In recent years, increasing evidence has accumulated that suggests the majority of cases of genital ulcer disease in sub-Saharan Africa are due to viral and not bacterial infections. Although many cross-sectional studies support such a trend, few serial cross-sectional data are available to show the evolution of genital ulcer disease over time. METHODS: We surveyed the prevalence of sexually transmitted diseases (STDs) among patients with STD symptoms and women recruited from family planning clinics in 3 cities in Botswana in 2002 and compared our findings with those from a survey of a similar population conducted in 1993. RESULTS: The observed proportion of cases of genital ulcer disease due to chancroid decreased from 25% in 1993 to 1% in 2002, whereas the proportion of ulcers due to herpes simplex virus increased from 23% in 1993 to 58% in 2002. Although the proportion of ulcers due to syphilis was similar for both surveys, the rate of positive serologic test results for syphilis among patients with genital ulcer disease decreased from 52% in 1993 to 5% in 2002. During this period, decreases in the prevalence of gonorrhea, syphilis-reactive serologic findings, chlamydial infection, and trichomoniasis were also detected among patients with STDs and women from family planning clinics. These changes remained significant after estimates were adjusted for the sensitivity and specificity of diagnostic tests. CONCLUSIONS: Our findings suggest a decrease in the prevalence of bacterial STDs and trichomoniasis, a reduction in the proportion of ulcers due to bacterial causes, and an increase in the proportion of ulcers due to herpes simplex virus during the period 1993-2002. These changes should be taken into consideration when defining new guidelines for the syndromic management of genital ulcer disease.  (+info)

Gender power imbalance on women's capacity to negotiate self-protection against HIV/AIDS in Botswana and South Africa. (45/208)

BACKGROUND: Gender power imbalance, which translates into a power imbalance in sexual interactions, is increasingly being recognized as a factor in fueling the spread of HIV/AIDS by increasing the number of unsafe sexual encounters. OBJECTIVES: To examine the influence of gender power imbalance and other factors on women's capacity to negotiate self protection against HIV infection; as well as men's response to the suggested condom use. METHODS: Drawing on data gathered from 2658 women aged 18-49 years in a cross-sectional survey in Kwa Zulu Natal Province of South Africa and Botswana, the study used descriptive statistics and logistic regression to reveal a number of gender related factors that significantly affect women's ability to protect themselves against HIV infection. RESULTS: Gender power imbalance significantly affects women's ability to suggest condom use to their partners. The study showed that it is women with partners 10 or more years older than them, abused women, and those economically dependent on their partners who are less likely to suggest condom use to their partners. Gender power imbalance also influences men's inclination towards refusing to use the suggested condom. The study showed that men are more likely to refuse to use the condom when the age difference between them and their female partners is wide, if they are in a married relationship, and where there is no communication about HIV/AIDS between them and their partners. What is more disturbing is the finding that it is men with multiple partners who are significantly more likely to refuse to use the condom. CONCLUSION: Across all levels of society, there is a need to see a social paradigm shift that transforms relationships between women and men, from the one of inequality and dominance as is the case in patriarchal societies, to equality, respect and consideration for one another.  (+info)

Two genotypic groups of morphologically similar fish trypanosomes from the Okavango Delta, Botswana. (46/208)

Blood smears and blood lysate samples from freshwater fishes captured in the Okavango Delta, Botswana, were examined to determine whether their trypanosomes were all Trypanosoma mukasai, a species of supposed broad host specificity and widespread existence across Africa. Trypanosomes and/or babesiosomes occurred in 20/32 blood smears, and morphometric analysis of trypanosomes from 13/32 smears showed features suggestive of T. mukasai, including nuclear indices consistently >1. In 16/32 blood lysate samples from which DNA was extracted, trypanosome DNA was detected in 12/16 by PCR (polymerase chain reaction), using trypanosome-specific ssu rRNA gene primers. Two samples positive for trypanosomes in blood smears yielded no amplifiable trypanosome DNA, but 4 samples with no detectable infection in blood smears were positive for trypanosome DNA, suggesting an overall trypanosome prevalence rate of 17/32 (53%) among fishes and demonstrating the value of PCR in trypanosome recognition. Cloning and sequencing of the 12 amplified fragments revealed 2 genotypic groups among these fish trypanosomes. Group 1 trypanosomes were from cichlids and 3 families of catfishes, Group 2 from 2 types of catfishes. Sequence comparison showed that the consensus Group 1 sequence was most similar to that of Trypanosoma cobitis, representing European fish trypanosomes of the carassii type, while the consensus Group 2 sequence showed similarity with a trypanosome sequence from another African catfish, Clarias angolensis. It was concluded that the identification of T. mukasai remains a problem, but at least 2 genotypic groups of trypanosomes occur in Okavango Delta fishes, and catfishes in this region appear to contain both types.  (+info)

Multilocus sequence typing reveals three genetic subpopulations of Cryptococcus neoformans var. grubii (serotype A), including a unique population in Botswana. (47/208)

We applied multilocus sequence typing (MLST) to investigate the population structure and mode of reproduction of Cryptococcus neoformans var. grubii (serotype A). This MLST system utilizes 12 unlinked polymorphic loci, which are dispersed on nine different chromosomes, and allows the unambiguous identification of closely related strains of serotype A. We compared MLST analyses with the conventional genotyping method of detecting amplified fragment length polymorphisms (AFLPs), and there was excellent correlation between the MLST and AFLP results. However, MLST differentiated a larger number of strains. We analyzed a global collection of isolates of serotype A using both methods, and the results identified at least three genetically distinct subpopulations, designated groups VNI, VNII, and VNB. Groups VNI and VNII are widespread, dominated by isolates with the MATalpha mating type, and predominantly clonal. Conversely, isolates of group VNB are unique to Botswana, include a significant proportion of fertile strains with the MATa mating type, and manifest compelling evidence of recombination. We have AFLP genotyped >1000 strains of serotype A from different parts of the world, including isolates from several African countries, and, to date, haploid serotype A isolates of group VNB have been found only in Botswana.  (+info)

Declining syphilis prevalence among pregnant women in northern Botswana: an encouraging sign for the HIV epidemic? (48/208)

OBJECTIVES: To evaluate trends in syphilis prevalence among antenatal women in a high HIV prevalence setting in northern Botswana. METHODS: Laboratory logbooks of antenatal syphilis testing for 1992-2003 in Francistown, Botswana's second largest city, were reviewed, and a consecutive sample of 750 women per year from 1992-2003 were analysed. VDRL result and age were recorded. A positive result was considered a case. RESULTS: Overall syphilis prevalence (VDRL positive) among pregnant women in Francistown decreased from 12.4% in 1992 to 4.3% in 2003 (p< or =0.001). The downward trend in overall syphilis prevalence began in 1997. There was no change in syphilis prevalence from 1992-6. Beginning in 1997, there has been a significant decrease in syphilis prevalence in all age groups. CONCLUSIONS: Syphilis in pregnant women in Francistown has been decreasing for the last 6 years, despite extremely high HIV prevalence (stable at > or =40% since 1996) in the same population. Reasons contributing to the decline in syphilis rates may include nationwide implementation of syndromic management of sexually transmitted diseases (STDs) in 1992, improved access to health care, and less risky sexual behaviour. There is evidence from other sources indicating that risky sexual behaviour in Botswana has decreased during the HIV epidemic.  (+info)