aLaboratory of Epidemiology and Biostatistics, Istituto Superiore di Sanità, Rome, Italy; bSt Mary's Hospital Lacor, Gulu, Uganda; and cDistrict Health Services, Gulu District, Ministry of Health, Uganda.
Received: 11 May 2001;
revised: 13 July 2001; accepted: 23 July 2001.
During the period 1996–1999, the prevalence of HIV-1 increased among pregnant women living in the rural areas of the Gulu district (North Uganda). This trend could be partly explained by the violent recrudescence of civil strife since 1996, which caused a dramatic reduction in activities of health education and a massive population displacement to protected camps. Screening and services for the prevention and control of HIV-1 should be promoted among displaced people.
During the period 1993–1997, an overall decrease in the prevalence of infection with HIV-1 was observed among women attending the antenatal clinic of St Mary's Hospital, Lacor, in the Gulu district of North Uganda . This decrease, which was consistent with national-level data , was observed both among women living in urban areas and among those living in rural areas. However, the overall decrease was mainly caused by a marked decrease until 1995, with the prevalence stabilizing in 1996, and slightly increasing in 1997. To determine whether or not this recent trend was the beginning of an actual increase in prevalence, we estimated the HIV-1 prevalence for the years 1996–1999 among women attending the same antenatal clinic.
During the period 1996–1999, a total of 12 687 women aged 15–49 years and living in the Gulu district attended the antenatal clinic and were anonymously screened for HIV-1 infection using an enzyme-linked immunosorbent assay. The tests were performed on the sera routinely collected for laboratory examinations during the first visit to the antenatal clinic, thus avoiding the repeated test of the same women in a single calendar year. We calculated the HIV-1 prevalence and the exact binomial 95% confidence intervals (CI). The odds ratios (OR) obtained by running logistic regression models were used to describe linear changes over time in the risk of being HIV-1 infected, adjusting for age and the area of residence (i.e. Gulu municipality and the remaining areas of the Gulu district), when appropriate. The chi-square for linear trend test was used for univariate analysis.
Independently of age and the area of residence, the overall HIV-1 prevalence showed a significant linear decrease over time (OR, 0.92; 95% CI, 0.87–0.97;P = 0.002) from 14.4% in 1996 (95% CI, 12.4–16.7%) to 12.1% in 1999 (95% CI, 11.2–13.1%). However, independently of age, the analysis of data by the area of residence showed that whereas the prevalence among the 6382 women living in urban areas (i.e. Gulu municipality) significantly decreased (OR, 0.69; 95% CI, 0.64–0.74;P < 0.001) from 17.2% in 1996 (95% CI, 13.8–21.1%) to 8.8% in 1999 (95% CI, 7.8–10.0%), the prevalence among the 6305 women living in rural areas significantly increased (OR, 1.14; 95% CI, 1.07–1.23;P < 0.001), from 12.6% in 1996 (95% CI, 10.2–15.4%) to 16.9% in 1999 (95% CI, 15.3–18.7%). When analysing data by age class, the trend of increase observed among the women living in rural areas was evident among women less than 30 years of age, with a statistically significant increase among those aged 25–29 years (P < 0.001), whereas no clear trend was observed among older women (Table 1).
The overall decrease in HIV-1 prevalence is consistent with data from other sentinel sites in Uganda; for example, among women attending the antenatal clinic of the Nsambya Hospital, located in Uganda's capital, Kampala, the HIV-1 prevalence decreased from 15.4% in 1996 to 12.3% in 1999 . The decrease could be explained both by the natural dynamics of the epidemic (i.e. increasing AIDS-related mortality) and, particularly for younger women, among whom change in prevalence more closely reflects incidence, by a reduction in risk behaviour and a consequent reduction in incidence, possibly partly as a result of prevention and control measures [3–5].
The increasing HIV-1 prevalence observed since 1997 in the rural areas of the Gulu district is more difficult to explain. Since 1996, there has been a violent recrudescence in civil strife, which has affected North Uganda for over 10 years; this has resulted in a drastic reduction in all activities of health education and prevention, especially in rural areas. Furthermore, civil strife has led to a massive population displacement to protected camps located in the rural areas surrounding the Gulu municipality; in 1999, 274 041 individuals (65.8% of the total rural population) were living in protected camps (unpublished data). The high population density in these camps could have contributed to the creation of a sub-population that is susceptible to new HIV-1 infections and which has less access to information and social services .
In conclusion, HIV-1 screening should be carried out among individuals living in protected camps, and if the prevalence is found to be high, services for the prevention and control of HIV-1 infection should be promoted among this large part of the population, particularly among younger people. In general, much attention should be paid to local contexts even when a generalized decline in HIV-1 prevalence is observed on a large scale.
Emingtone O. Ayellab
Maria G. Dentea
Paul A. Onekc
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