Abstinence programmes do not reduce HIV prevalence in Uganda
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《英国医生杂志》
Use of condoms and death explain the substantial decline in the prevalence of HIV in Uganda in the past decade.
The reduction had previously been credited to ABC programmes (abstinence, be faithful, and use condoms). A longitudinal study, presented at the 12th retroviral conference in Boston, however, challenges the contributions of abstinence and fidelity. The study included a door to door survey of about 10 000 adults aged 15-49 in 44 villages in the Rakai district of southern Uganda.
A surge of infections in the early 1990s is the cause of rising numbers of deaths. In 2001-2, 125 cases of seroconversion added to the prevalence, and 200 died. "Death alone accounted for a six percentage point reduction in HIV prevalence in the one year," Maria Wawer, a public health researcher from Columbia University, New York city, said. "Overall, the HIV prevalence over the last decade declined 6.2 percentage points. We estimate that mortality alone contributed five percentage points of the decline."
The remaining share could not be attributed to abstinence. The proportion of men reporting sexual abstinence in the past year declined, but the proportion among women did not change. Nor could the decline be credited to fidelity because the proportion of men reporting two or more partners in the past year increased in the decade.
Sexual abstinence among men aged 15-49 in Uganda declined between 2001-2 and 2002-3
Credit: SIPA/REX
Use of condoms increased dramatically. "Condom use is much higher with casual partners than with their married partner," Dr Wawer said. "Condom use is associated with the significant reduction of HIV acquisition in this population."
The most troubling aspect of the analysis is that men who have seroconverted within the past year reported having about twice as many sexual partners as men who have not seroconverted. The probability of transmitting HIV per coital act is about 10 times higher for someone who recently seroconverted. This group accounts for roughly half of all new infections in Uganda. As a result, the overall incidence has edged upwards from 1.3 per 100 people per year in 1994-5 to 1.7 in 2002-3.
The study began in 1994 and consisted of a behavioural questionnaire and an analysis of collected blood and urine samples. Its annual compliance rate was 85-90%. Researchers from Johns Hopkins University, in Baltimore, Maryland, and Makerere University in Kampala, Uganda, led the collaborative effort.
HIV prevalence in women was 19.7% in 1994 and fell by a third to 12.9% in 2003, the last year for which full analysis of the data was complete. For men, prevalence declined by 38% from 15.0% to 9.3% in the same period. (see p 498.)(Bob Roehr)
The reduction had previously been credited to ABC programmes (abstinence, be faithful, and use condoms). A longitudinal study, presented at the 12th retroviral conference in Boston, however, challenges the contributions of abstinence and fidelity. The study included a door to door survey of about 10 000 adults aged 15-49 in 44 villages in the Rakai district of southern Uganda.
A surge of infections in the early 1990s is the cause of rising numbers of deaths. In 2001-2, 125 cases of seroconversion added to the prevalence, and 200 died. "Death alone accounted for a six percentage point reduction in HIV prevalence in the one year," Maria Wawer, a public health researcher from Columbia University, New York city, said. "Overall, the HIV prevalence over the last decade declined 6.2 percentage points. We estimate that mortality alone contributed five percentage points of the decline."
The remaining share could not be attributed to abstinence. The proportion of men reporting sexual abstinence in the past year declined, but the proportion among women did not change. Nor could the decline be credited to fidelity because the proportion of men reporting two or more partners in the past year increased in the decade.
Sexual abstinence among men aged 15-49 in Uganda declined between 2001-2 and 2002-3
Credit: SIPA/REX
Use of condoms increased dramatically. "Condom use is much higher with casual partners than with their married partner," Dr Wawer said. "Condom use is associated with the significant reduction of HIV acquisition in this population."
The most troubling aspect of the analysis is that men who have seroconverted within the past year reported having about twice as many sexual partners as men who have not seroconverted. The probability of transmitting HIV per coital act is about 10 times higher for someone who recently seroconverted. This group accounts for roughly half of all new infections in Uganda. As a result, the overall incidence has edged upwards from 1.3 per 100 people per year in 1994-5 to 1.7 in 2002-3.
The study began in 1994 and consisted of a behavioural questionnaire and an analysis of collected blood and urine samples. Its annual compliance rate was 85-90%. Researchers from Johns Hopkins University, in Baltimore, Maryland, and Makerere University in Kampala, Uganda, led the collaborative effort.
HIV prevalence in women was 19.7% in 1994 and fell by a third to 12.9% in 2003, the last year for which full analysis of the data was complete. For men, prevalence declined by 38% from 15.0% to 9.3% in the same period. (see p 498.)(Bob Roehr)