Commercial sex and the spread of HIV in four cities in sub-Saharan Africa.

OBJECTIVE: To examine whether commercial sex transactions were more common and/or transmission between sex workers and clients more efficient in two African cities with high HIV prevalence (Kisumu, Kenya and Ndola, Zambia) compared with two with relatively low HIV prevalence (Cotonou, Benin and Yaoundé, Cameroon). METHODS: Data on sexual behaviour, HIV and sexually transmitted infections were collected from representative samples of around 300 female sex workers in each city. Sexual behaviour data from a population-based study of around 1000 men aged 15-49 in each city were used to estimate the extent of contact with sex workers. RESULTS: The number of sex workers per 1000 males was highest in Kisumu and Ndola, but other estimates of the extent or characteristics of sex work contact showed no consistent differences between high or low prevalence cities. HIV prevalence among sex workers was 75% in Kisumu, 69% in Ndola, 55% in Cotonou and 34% in Yaoundé. The prevalence of genital ulceration and trichomoniasis was higher among sex workers in Kisumu and Ndola but no clear pattern was seen for the other sexually transmitted infections. Around 70% of sex workers in Cotonou reported use of a condom with the last client, markedly higher than in the other cities. CONCLUSIONS: Although sex work is likely to have played an important role in the spread of HIV in all four cities, differences in present patterns of sex work do not appear to explain the differential spread of HIV. However, high levels of condom use among sex workers may have slowed the spread from sex workers to the general population in Cotonou, highlighting the importance of interventions among sex workers and their clients

Estimation of radiation hazard indices from syenite building rocks in the South-western region of Cameroon

Radium equivalent (Raeq) and external hazard index (Hex) were estimated based on 226Ra, 232Th and 40K measurements in syenite building rocks collected from various sampling sites of Lolodorf area, South-western region of Cameroon to assess the radiation hazards due to the use of these rocks in dwellings construction. The analysis has been carried out by γ-ray spectrometry using a high purity germanium (HPGe) detector. Raeq varied from 186 ± 4 to 2564 ± 24 Bq · kg−1, while Hex varied from 0.5 ± 0.01 to 6.93 ± 0.06. The corresponding mean values are 1463 ± 930 Bq · kg−1 and 3.95 ± 2.51 in Awanda subdivision while in Madong subdivision, these values are 683 ± 553 Bq · kg−1 and 1.84 ± 1.49, respectively. Absorbed dose rate ranged from 98 ± 2 to 1171 ± 11 nGy · h−1 while annual effective dose ranged from 0.60 to 7.18 mSv · year−1. The average absorbed dose rates are 670 ± 420 nGy · h−1 and 313 ± 245 nGy · h−1 in Awanda and Madong, respectively. These average values give rise to a mean annual effective dose of 4.11 mSv · year−1 and 1.92 mSv · year−1. All syenite building rocks have shown Raeq activity concentrations higher than the limit set in the Organization for Economic Cooperation and Development (370 Bq · kg−1), equivalent to external gamma dose of 1.5 mSv · year−1. The obtained values of the annual external effective dose in Awanda and Madong are higher (nine-fold and four-fold, respectively) than the worldwide mean annual effective dose (0.48 mSv · year−1). The syenite rocks in the corresponding localities can be considered as high radiation's material not recommended for dwellings construction

Educational level is associated with condom use within non-spousal partnerships in four cities of sub-Saharan Africa

Not the final published versionBACKGROUND: Rates of condom use in sub-Saharan Africa have remained too low to curb HIV/sexually transmitted disease (STD) epidemics. A better understanding of the main determinants of condom use would aid promotion. METHODS: Cross-sectional population surveys were conducted in four cities in sub-Saharan Africa: Yaoundé, Cameroon; Cotonou, Benin; Ndola, Zambia; and Kisumu, Kenya. In each city, the aim was to interview a random sample of 1000 men and 1000 women aged 15--49 years, including questions on characteristics of non-spousal partnerships in the past 12 months. RESULTS: Data on condom use were available for 4624 non-spousal partnerships. In the four cities, the proportion of partnerships in which condoms were used always or most of the time ranged from 23.8 to 33.5% when reported by men and from 10.7 to 25.9% when reported by women. Based on the reports from men, condom use was associated with higher educational level of the male partner in Yaoundé [adjusted odds ratio (aOR) = 1.76] and Ndola (aOR = 2.94) and with higher educational level of the female partner in Cotonou (aOR = 2.36) and Kisumu (aOR = 2.76). Based on the reports from women, condom use was associated with higher educational level of the female partner in Kisumu (aOR = 2.60) and Ndola (aOR = 4.50) and with higher educational level of the male partner in Yaoundé (aOR = 3.32). Associations with other determinants varied across cities and for men and women. CONCLUSIONS: Education was found to be a key determinant of condom use in all four cities. This suggests that educational level increases response to condom promotion and highlights the need for special efforts to reach men and women with low educational attainment