HIV-1 Infection Prevalence and Incidence Trends in Areas of Contrasting Levels of Infection in the Kagera Region, Tanzania, 1987-2000

Abstract

This study aimed at assessing the extent to which decline in HIV infection prevalence reflects decline in incidence in 3 areas with contrasting initial exposure to the HIV epidemic in the Kagera region of Tanzania. A population sample was recruited for the baseline study in 1987 through a multistage cluster sampling technique to determine HIV prevalence. Seronegative individuals identified in the baseline and subsequent studies were followed up for 3 years to yield trends in incidence that were compared for the 3 areas. The overall age-adjusted HIV-1 prevalence in the high-prevalence area of Bukoba urban declined significantly from 24.2% in 1987 to 18.2% in 1993 and later to 13.3% in 1996 (P = 0.0001). In the medium-prevalence area of Muleba, overall age-adjusted prevalence declined significantly from 10.0% in 1987 to 6.8% in 1996 and later to 4.3% in 1999 (P = 0.0003), whereas in the low-prevalence area of Karagwe the prevalence declined from 4.5% in 1987 to 2.6% in 1999 (P = 0.01). In all 3 areas, the most significant decline was consistently observed among women in the age group 15-24 years. No age group exhibited a significant upward prevalence trend. The HIV-1 incidence for Bukoba urban declined from 47.5 to 9.1 per 1000 person-years of observation in 1989 and 1996, respectively, whereas in Muleba it decreased from 8.2 to 3.9 in 1989 and 2000, respectively. Sex-specific estimates indicated a significant decline among women in the high-prevalence area of Bukoba urban from 51.5 to 9.2 per 1000 person-years at risk (P = 0.001). It is concluded that the HIV-1 epidemic in Kagera is on the decrease as reflected by the decline in HIV-1 incidence and prevalence trends particularly among the 15-24 year olds. The decline in the 3 areas of differing magnitude implies that the HIV/AIDS epidemic may be arrested early without necessarily peaking to saturation levels.

Social capital and the decline in HIV transmission – A case study in three villages in the Kagera region of Tanzania

“…Key informant interviews and focus group discussions (FGDs) were performed in three case villages selected to represent high, medium and low prevalence zones, based on estimates from the 1987 survey (Kwesigabo et al, 2005). The study was performed in one ward in each of the identified zones.…”

Exploring the role of cognitive and structural forms of social capital in HIV/AIDS trends in the Kagera region of Tanzania – a grounded theory study

“…The Kagera region, which had high levels of HIV prevalence in the late 1980s, ranging from 4.5% in the rural Karagwe district to 24% in the urban Bukoba district, has witnessed a decline in HIV, especially in the previously high-prevalence urban district. In all three zones of the study area, the decline was more pronounced among women (see Table 1) (Killewo, Sandstrom, Bredberg-Rådén, Mhalu, Biberfeld & Wall, 1993;Kwesigabo, 2001;Kwesigabo, Killewo, Urassa, Lugalla, Emmelin & Mutembei, 2005).…”

“…These include health education, voluntary counselling and testing for HIV (VCT), and promotion of condom use and an increased use of condoms (Kwesigabo et al, 2005). Increased awareness and knowledge about the causes and prevention of HIV and AIDS has been accompanied by more openness and a decrease in HIV stigma.…”

“…It is rare to find HIV infections of long duration in this age group since almost all the infections will have been recently acquired and hence constitute incident cases (Kwesigabo et al, 2005).…”

“…All interviews and discussions were tape recorded, transcribed verbatim, and translated to English for facilitated joint analysis by the research group. Kwesigabo et al (2005) The FGD participants were selected to form homogenous groups by age and sex in order to facilitate free discussion among the members. Data collection and analysis proceeded iteratively.…”