A population-based study on alcohol and high-risk sexual behaviors in Botswana. (57/208)

BACKGROUND: In Botswana, an estimated 24% of adults ages 15-49 years are infected with HIV. While alcohol use is strongly associated with HIV infection in Africa, few population-based studies have characterized the association of alcohol use with specific high-risk sexual behaviors. METHODS AND FINDINGS: We conducted a cross-sectional, population-based study of 1,268 adults from five districts in Botswana using a stratified two-stage probability sample design. Multivariate logistic regression was used to assess correlates of heavy alcohol consumption (>14 drinks/week for women, and >21 drinks/week for men) as a dependent variable. We also assessed gender-specific associations between alcohol use as a primary independent variable (categorized as none, moderate, problem and heavy drinking) and several risky sex outcomes including: (a) having unprotected sex with a nonmonogamous partner; (b) having multiple sexual partners; and (c) paying for or selling sex in exchange for money or other resources. Criteria for heavy drinking were met by 31% of men and 17% of women. Adjusted correlates of heavy alcohol use included male gender, intergenerational relationships (age gap > or =10 y), higher education, and living with a sexual partner. Among men, heavy alcohol use was associated with higher odds of all risky sex outcomes examined, including unprotected sex (AOR = 3.48; 95% confidence interval [CI], 1.65 to 7.32), multiple partners (AOR = 3.08; 95% CI, 1.95 to 4.87), and paying for sex (AOR = 3.65; 95% CI, 2.58 to 12.37). Similarly, among women, heavy alcohol consumption was associated with higher odds of unprotected sex (AOR = 3.28; 95% CI, 1.71 to 6.28), multiple partners (AOR = 3.05; 95% CI, 1.83 to 5.07), and selling sex (AOR = 8.50; 95% CI, 3.41 to 21.18). A dose-response relationship was seen between alcohol use and risky sexual behaviors, with moderate drinkers at lower risk than both problem and heavy drinkers. CONCLUSIONS: Alcohol use is associated with multiple risks for HIV transmission among both men and women. The findings of this study underscore the need to integrate alcohol abuse and HIV prevention efforts in Botswana and elsewhere.  (+info)

Serological evidence of HIV-associated infection among HIV-1-infected adults in Botswana. (58/208)

In industrialized countries, it is recommended that adults with human immunodeficiency virus type 1 (HIV-1) infection undergo baseline screening for pathogens that might cause latent or active infections, such as syphilis, hepatitis B, hepatitis C, infection due to Toxoplasma gondii, and cytomegalovirus infection. A paucity of data exist from sub-Saharan Africa describing the prevalence of these pathogens. We report data for HIV-1-infected adults referred for initiation of highly active antiretroviral therapy in Botswana.  (+info)

The emergence of HIV transmitted resistance in Botswana: "when will the WHO detection threshold be exceeded?". (59/208)

BACKGROUND: The Botswana antiretroviral program began in 2002 and currently treats 42,000 patients, with a goal of treating 85,000 by 2009. The World Health Organization (WHO) has begun to implement a surveillance system for detecting transmitted resistance that exceeds a threshold of 5%. However, the WHO has not determined when this threshold will be reached. Here we model the Botswana government's treatment plan and predict, to 2009, the likely stochastic evolution of transmitted resistance. METHODS: We developed a model of the stochastic evolution of drug-resistant strains and formulated a birth-death Master equation. We analyzed this equation to obtain an analytical solution of the probabilistic evolutionary trajectory for transmitted resistance, and used treatment and demographic data from Botswana. We determined the temporal dynamics of transmitted resistance as a function of: (i) the transmissibility (i.e., fitness) of the drug-resistant strains that may evolve and (ii) the rate of acquired resistance. RESULTS: Transmitted resistance in Botswana will be unlikely to exceed the WHO's threshold by 2009 even if the rate of acquired resistance is high and the strains that evolve are half as fit as the wild-type strains. However, we also found that transmission of drug-resistant strains in Botswana could increase to approximately 15% by 2009 if the drug-resistant strains that evolve are as fit as the wild-type strains. CONCLUSIONS: Transmitted resistance will only be detected by the WHO (by 2009) if the strains that evolve are extremely fit and acquired resistance is high. Initially after a treatment program is begun a threshold lower than 5% should be used; and we advise that predictions should be made before setting a threshold. Our results indicate that it may be several years before the WHO's surveillance system is likely to detect transmitted resistance in other resource-poor countries that have significantly less ambitious treatment programs than Botswana.  (+info)

Seeds use temperature cues to ensure germination under nurse-plant shade in xeric Kalahari savannah. (60/208)

BACKGROUND AND AIMS: In arid environments many plant species are found associated with the canopies of woody perennials. Favourable conditions for establishment under canopies are likely to be associated with shade, but under canopies shade is distributed patchily and differs in quality. Diurnal temperature fluctuations and maximum temperatures could be reliable indicators of safe sites. Here, an examination is made as to whether canopy-associated species use temperature cues to germinate in shade patches, rather than matrix areas between trees. METHODS: The study was carried out in arid southern Kalahari savannah (Republic of South Africa). Perennial and annual species associated with Acacia erioloba trees and matrix species were germinated at temperature regimes resembling shaded and unshaded conditions. Soil temperature was measured in the field. KEY RESULTS: Germination of all fleshy-fruited perennial acacia-associated species and two annual acacia-associated species was inhibited by the temperature regime resembling unshaded conditions compared with at least one of the regimes resembling shaded conditions. Inhibition in perennials decreased with seed mass, probably reflecting that smaller seedlings are more vulnerable to drought. Germination of matrix species was not inhibited by the unshaded temperature regime and in several cases it increased germination compared with shaded temperature regimes or constant temperature. Using phylogenetically independent contrasts a significant positive relationship was found between canopy association and the germination at shade temperatures relative to unshaded temperatures. CONCLUSIONS: The data support the hypothesis that canopy species have developed mechanisms to prevent germination in open sun conditions. The results and data from the literature show that inhibition of germination at temperature regimes characteristic of open sun conditions can be found in fleshy-fruited species of widely divergent taxonomic groups. It is predicted that germination mechanisms to detect canopy shade based on temperature cues are widespread in species depending on nurse plants, especially bird-dispersed species.  (+info)

Modelling the public health impact of male circumcision for HIV prevention in high prevalence areas in Africa. (61/208)

BACKGROUND: Recent clinical trials in Africa, in combination with several observational epidemiological studies, have provided evidence that male circumcision can reduce HIV female-to-male transmission risk by 60% or more. However, the public health impact of large-scale male circumcision programs for HIV prevention is unclear. METHODS: Two mathematical models were examined to explore this issue: a random mixing model and a compartmental model that distinguishes risk groups associated with sex work. In the compartmental model, two scenarios were developed, one calculating HIV transmission and prevalence in a context similar to the country of Botswana, and one similar to Nyanza Province, in western Kenya. RESULTS: In both models, male circumcision programs resulted in large and sustained declines in HIV prevalence over time among both men and women. Men benefited somewhat more than women, but prevalence among women was also reduced substantially. With 80% male circumcision uptake, the reductions in prevalence ranged from 45% to 67% in the two "countries", and with 50% uptake, from 25% to 41%. It would take over a decade for the intervention to reach its full effect. CONCLUSION: Large-scale uptake of male circumcision services in African countries with high HIV prevalence, and where male circumcision is not now routinely practised, could lead to substantial reductions in HIV transmission and prevalence over time among both men and women.  (+info)

Chlamydia and gonorrhoea in pregnant Batswana women: time to discard the syndromic approach? (62/208)

BACKGROUND: Chlamydia and gonorrhoea are major causes of morbidity among women in developing countries. Both infections have been associated with pregnancy-related complications, and case detection and treatment in pregnancy is essential. In countries without laboratory support, the diagnosis and treatment of cervical infections is based on the syndromic approach. In this study we measured the prevalence of chlamydia and gonorrhoea among antenatal care attendees in Botswana. We evaluated the syndromic approach for the detection of cervical infections in pregnancy, and determined if risk scores could improve the diagnostic accuracy. METHODS: In a cross-sectional study, 703 antenatal care attendees in Botswana were interviewed and examined, and specimens were collected for the identification of C trachomatis, N gonorrhoeae and other reproductive tract infections. Risk scores to identify attendees with cervical infections were computed based on identified risk factors, and their sensitivities, specificities, likelihood ratios and predictive values were calculated. RESULTS: The prevalence of chlamydia was 8%, and gonorrhoea was found in 3% of the attendees. Symptoms and signs of vaginal discharge did not predict cervical infection, and a syndromic approach failed to identify infected women. Age (youth) risk factor most strongly associated with cervical infection. A risk score with only sociodemographic factors had likelihood ratios equivalent to risk scores which incorporated clinical signs and microscopy results. However, all the evaluated risk scores were of limited value in the diagnosis of chlamydia and gonorrhoea. A cut-off set at an acceptable sensitivity to avoid infected antenatal care attendees who remained untreated would inevitably lead to considerable over-treatment. CONCLUSION: Although in extensive use, the syndromic approach is unsuitable for diagnosing cervical infections in antenatal care attendees in Botswana. None of the evaluated risk scores can replace this management. Without diagnostic tests, there are no adequate management strategies for C trachomatis and N gonorrhoeae in pregnant women in Botswana, a situation which is likely to apply to other countries in sub-Saharan Africa. Screening for cervical infections in pregnant women is an essential public health measure, and rapid tests will hopefully be available in developing countries within a few years.  (+info)

Seroprevalence of selected infectious agents in a free-ranging, low-density lion population in the Central Kalahari Game Reserves in Botswana. (63/208)

Twenty-one free-ranging Central Kalahari lions (Panthera leo) exhibited a high prevalence rate of feline herpesvirus (100%) and feline immunodeficiency virus (71.4%). Canine distemper virus and feline calicivirus occurred with a low prevalence. All individuals tested negative for feline coronavirus, feline parvovirus, feline leukemia virus, Ehrlichia canis, and Anaplasma phagocytophilum.  (+info)

Recent multiple sexual partners and HIV transmission risks among people living with HIV/AIDS in Botswana. (64/208)

BACKGROUND: HIV prevalence in Botswana is among the highest in the world and sexual networking patterns represent an important dimension to understanding the spread of HIV/AIDS. AIM: To examine risk behaviour associated with recent multiple sexual partnerships among people living with HIV/AIDS in Botswana. METHODS: Confidential brief interviews were administered to 209 HIV positive men and 291 HIV positive women recruited conveniently from HIV/AIDS support groups and antiretroviral clinics. Measures included demographics, duration of HIV diagnosis, sexual partnerships, condom use, and HIV status disclosure. RESULTS: The response rate was 63% and 309 (62%) participants were currently sexually active, of whom 247 (80%) reported only one sex partner in the previous 3 months and 62 (20%) reported two or more partners during that time. Condom use exceeded 80% across partner types and regardless of multiple partnerships. Steady sex partners of participants with multiple partnerships were significantly less likely to be protected by condoms than steady partners of individuals with only one sex partner. Individuals with multiple sex partners were also significantly less likely to have disclosed their HIV status. CONCLUSIONS: Multiple sexual partnerships, many of which are probably concurrent, are not uncommon among sexually active people living with HIV in Botswana. HIV prevention is needed for all individuals who are at risk and assistance should be provided to HIV infected people who continue to practise unprotected sex with uninfected partners or partners of unknown HIV status.  (+info)