A home-based counselling and testing (HBCT) programme in western Kenya achieved 96% uptake of HIV testing and identified almost 5400 undiagnosed infections among over 154,000 adolescents and adults, according to a retrospective analysis published in the advance online edition of the Journal of Acquired Immune Deficiency Syndromes.
Those who had previously tested for HIV were less likely to accept HIV testing (aOR: 0.06, 95%CI: 0.05-0.07) but more likely to test positive (aOR: 1.30, 95% CI: 1.21-1.4); this was true for all age groups but especially so for young adults.
The study found that HIV prevalence increased with age but, despite this, adolescents had a significantly higher risk of HIV infection.
These findings offer important new insights when considering HIV prevention and treatment strategies.
Early diagnosis and prompt treatment of HIV is recognised as an effective means to reduce HIV transmission and HIV death and disease rates. Recent studies have provided evidence of the efficacy of HIV treatment as prevention.
Research is focused increasingly on studies showing how to promote high coverage of HIV testing, repeat testing, linkage to and retention in care, yet HIV testing still remains a critical gateway to HIV prevention and treatment, the authors write.
Among the various testing strategies in sub-Saharan Africa, HBCT has been shown to be the most effective in improving testing uptake and the timely enrolment of people with HIV into care. Reasons for its success include that testing in the privacy of one’s home effectively deals with the common institutional challenges of distance to test centres, transportation costs, stigma linked to testing centres, as well as confidentiality concerns.
Understanding issues affecting HIV testing uptake and prevalence across the life cycle is essential for HIV prevention programmes to define effective population-based testing and prevention strategies. Additionally, the acceptability of repeat testing is still of concern, note the authors.
So the authors chose to describe HIV testing uptake and prevalence in adolescents, younger adults and older adults and to compare factors linked to testing uptake and prevalence among the three age groups.
The USAID-Academic Model Providing Access to Healthcare (AMPATH) partnership currently provides HIV care and treatment to over 76,000 people living with HIV in 65 Ministry of Health (MOH) facilities throughout western Kenya. In 2007, AMPATH began an HBCT programme rolled out to eight catchment areas. A catchment area was defined as an area assigned to AMPATH by the MOH for the provision of health services.
Data collected between November 2009 and January 2012, for individuals aged 13 and over during HBCT, from five catchment areas (Burnt Forest, Chulaimbo, Teso, Port Victoria and Kapsaret) were included in the analysis.
Primary outcome variables were HIV testing uptake (accepted compared to refused) and HIV prevalence (positive compared to negative).
Explanatory variables comprised
- Socio-demographic characteristics: age in years, gender, orphan status for adolescents, relationship status;
- Socio-economic characteristics: education level, occupation, number in household, HBCT catchment area; and
- HIV testing data (including previous testing and results).
Of the 154,463 individuals included in the analysis 22% (34,733) were adolescents, 19% (28,642) younger adults and 59% (91,088) older adults. The mean age was 32.8 years with slightly over half being female (56%).
Consistent with other studies, testing uptake was high across all age groups, 99, 98 and 94% (p<0.001) among adolescents, younger adults and older adults, respectively.
Overall prevalence was higher than the reported national prevalence, 7.6% compared to 6.3%. The authors suggest this may be explained by the MOH sampling procedure used that differed from their study’s population-based testing. A true HIV prevalence capturing the entire population in Kenya is needed; HBCT may be a means to do this, write the authors.
Consistent with other findings from sub-Saharan Africa socio-demographic and socio-economic factors affected HIV testing uptake and prevalence.
With each year increase in age individuals were less likely to accept testing. Among younger adults not only were they less likely to accept testing (aOR: 0.83, 95% CI: 0.78-0.88) but more likely to test positive with each year increase in age (aOR: 1.22, 95% CI: 1.16-1.27).
Females were more likely to test positive (aOR: 1.30, 95% CI: 1.23-1.38), in particular adolescents and younger adults.
Those who had previously tested were reluctant to test again, consistent with findings from Uganda, note the authors. Strategies encouraging repeat testing, including among those who consider themselves at minimal risk, are urgently needed, they add.
Older adults in a relationship were more likely to accept testing; HBCT may be an effective strategy to promote couple counselling and testing.
Consistent with other findings, couples cohabiting reported the highest prevalence (14.9%). Those separated (9.2%), widowed (7%) or divorced (9.7%) had a higher prevalence than those single (4.7%) or married (4.4%). Findings, they note, that warrant research.
While prevalence increased with age these findings “highlight the vulnerability of adolescents in general as a high risk group…Safer sex intervention programmes as well as female empowerment initiatives involving the full participation of adolescents need to be strengthened.”
Individuals employed were more likely to test positive. While further research is needed to understand this, HIV workplace prevention programmes need to be strengthened, the authors write.
The authors conclude “Our data provide evidence of socio-demographic and socio-economic factors that influence individuals’ acceptance of HIV testing and the likelihood of being infected. The age-cohort variations…give us insight into how to define well-tailored HIV prevention programmes across the life-cycle…findings…may be useful in developing and improving approaches to HIV prevention and uptake of care.”
Wachira J et al. HIV testing uptake and prevalence among adolescents and adults in a large home-based HIV testing program in western Kenya. Advance online edition, J Acquir Immun Defic Syndr, doi:10.1097/QAI.0b013e31282a14f9e, 2013.