Accuracy in HIV Rapid Testing among Laboratory and Non-laboratory Personnel in Zambia: Observations from the National HIV Proficiency Testing System.

BACKGROUND: Despite rapid task-shifting and scale-up of HIV testing services in high HIV prevalence countries, studies evaluating accuracy remain limited. This study aimed to assess overall accuracy level and factors associated with accuracy in HIV rapid testing in Zambia. METHODS: Accuracy was investigated among rural and urban HIV testing sites participating in two annual national HIV proficiency testing (PT) exercises conducted in 2009 (n = 282 sites) and 2010 (n = 488 sites). Testers included lay counselors, nurses, laboratory personnel and others. PT panels of five dry tube specimens (DTS) were issued to testing sites by the national reference laboratory (NRL). Site accuracy level was assessed by comparison of reported results to the expected results. Non-parametric rank tests and multiple linear regression models were used to assess variation in accuracy between PT cycles and between tester groups, and to examine factors associated with accuracy respectively. RESULTS: Overall accuracy level was 93.1% (95% CI: 91.2-94.9) in 2009 and 96.9% (95% CI: 96.1-97.8) in 2010. Differences in accuracy were seen between the tester groups in 2009 with laboratory personnel being more accurate than non-laboratory personnel, while in 2010 no differences were seen. In both PT exercises, lay counselors and nurses had more difficulties interpreting results, with more occurrences of false-negative, false-positive and indeterminate results. Having received the standard HIV rapid testing training and adherence to the national HIV testing algorithm were positively associated with accuracy. CONCLUSION: The study showed an improvement in tester group and overall accuracy from the first PT exercise to the next. Average number of incorrect test results per 1000 tests performed was reduced from 69 to 31. Further improvement is needed, however, and the national HIV proficiency testing system seems to be an important tool in this regard, which should be continued and needs to be urgently strengthened.

Task-Shifting and Quality of HIV Testing Services: Experiences from a National Reference Hospital in Zambia.

BACKGROUND: With new testing technologies, task-shifting and rapid scale-up of HIV testing services in high HIV prevalence countries, assuring quality of HIV testing is paramount. This study aimed to explore various cadres of providers' experiences in providing HIV testing services and their understanding of elements that impact on quality of service in Zambia. METHODS: Sixteen in-depth interviews and two focus group discussions were conducted with HIV testing service providers including lay counselors, nurses and laboratory personnel at purposively selected HIV testing sites at a national reference hospital in Lusaka. Qualitative content analysis was adopted for data analysis. RESULTS: Lay counselors and nurses reported confidentiality and privacy to be greatly compromised due to limited space in both in- and out-patient settings. Difficulties in upholding consent were reported in provider-initiated testing in in-patient settings. The providers identified non-adherence to testing procedures, high workload and inadequate training and supervision as key elements impacting on quality of testing. Difficulties related to testing varied by sub-groups of providers: lay counselors, in finger pricking and obtaining adequate volumes of specimen; non-laboratory providers in general, in interpreting invalid, false-negative and false-positive results. The providers had been participating in a recently established national HIV quality assurance program, i.e. proficiency testing, but rarely received site supervisory visits. CONCLUSION: Task-shifting coupled with policy shifts in service provision has seriously challenged HIV testing quality, protection of confidentiality and the process of informed consent. Ways to better protect confidentiality and informed consent need careful attention. Training, supervision and quality assurance need strengthening tailored to the needs of the different cadres of providers.

The seven Cs of the high acceptability of home-based VCT: results from a mixed methods approach in Zambia.

HIV testing and counselling is a critical gateway to prevention and treatment. Yet, coverage remains insufficient, few couples are tested together and gender differences in access exist. We used an embedded mixed methods approach to investigate possible explanations for the high acceptance of home-based voluntary HIV counselling and testing (HB-VCT) in a pair-matched cluster-randomized trial in Zambia. A baseline survey included 1694 individuals in 36 clusters. Adults in 18 intervention clusters were offered HB-VCT by lay counsellors. Standard testing services were available in both trial arms. After the completion of the intervention, a follow-up survey was conducted in all trial clusters. In addition, 21 in-depth interviews and one focus group discussion were conducted with home-based VCT clients in the intervention arm. Informants favoured the convenience, confidentiality and credibility of HB-VCT. Counsellors were perceived as trustworthy owing to their closeness and conduct, and the consent process was experienced as convincing. Couple testing was selected by 70% of cohabiting couples and was experienced as beneficial by both genders. Levels of first-time testing (68% vs. 29%, p < 0.0001) and re-testing (94% vs. 74%, p < 0.0001) were higher in the intervention than in the control arm. Acceptance of HIV testing and counselling is dependent on stigma, trust and gender. The confidentiality of home-based VCT was essential for overcoming stigma-related barriers, and the selection of local counsellors was important to ensure trust in the services. The high level of couple counselling within HB-VCT may contribute to closing the gender gap in HIV testing, and has benefits for both genders and potentially for prevention of HIV transmission. The study demonstrates the feasibility of achieving high test coverage with an opt-in consent approach. The embedded qualitative component confirmed the high satisfaction with HB-VCT reported in the quantitative survey and was crucial to fully understand the intervention and its consequences.

Strong effects of home-based voluntary HIV counselling and testing on acceptance and equity: a cluster randomised trial in Zambia.

Home-based voluntary HIV counselling and testing (HB-VCT) has been reported to have a high uptake, but it has not been rigorously evaluated. We designed a model for HB-VCT appropriate for wider scale-up, and investigated the acceptance of home-based counselling and testing, equity in uptake and negative life events with a cluster-randomized trial. Thirty six rural clusters in southern Zambia were pair-matched based on baseline data and randomly assigned to the intervention or the control arm. Both arms had access to standard HIV testing services. Adults in the intervention clusters were offered HB-VCT by local lay counsellors. Effects were first analysed among those participating in the baseline and post-intervention surveys and then as intention-to-treat analysis. The study was registered with www.controlled-trials.com, number ISRCTN53353725. A total of 836 and 858 adults were assigned to the intervention and control clusters, respectively. In the intervention arm, counselling was accepted by 85% and 66% were tested (n = 686). Among counselled respondents who were cohabiting with the partner, 62% were counselled together with the partner. At follow-up eight months later, the proportion of adults reporting to have been tested the year prior to follow-up was 82% in the intervention arm and 52% in the control arm (Relative Risk (RR) 1.6, 95% CI 1.4-1.8), whereas the RR was 1.7 (1.4-2.0) according to the intention-to-treat analysis. At baseline the likelihood of being tested was higher for women vs. men and for more educated people. At follow-up these differences were found only in the control communities. Measured negative life events following HIV testing were similar in both groups. In conclusion, this HB-VCT model was found to be feasible, with a very high acceptance and to have important equity effects. The high couple counselling acceptance suggests that the home-based approach has a particularly high HIV prevention potential.

Immunogenicity of standard-titer measles vaccine in HIV-1-infected and uninfected Zambian children: an observational study.

BACKGROUND: Achieving the level of population immunity required for measles elimination may be difficult in regions of high human immunodeficiency virus type 1 (HIV-1) prevalence, because HIV-1-infected children may be less likely to respond to or maintain protective antibody levels after vaccination. METHODS: We conducted a prospective study of the immunogenicity of standard-titer measles vaccine administered at 9 months of age to HIV-1-infected and uninfected children in Lusaka, Zambia. RESULTS: From May 2000 to November 2002, 696 children aged 2-8 months were enrolled. Within 6 months of vaccination, 88% of 50 HIV-1-infected children developed antibody levels of >or=120 mIU/mL, compared with 94% of 98 HIV-seronegative children and 94% of 211 HIV-seropositive but uninfected children (P=.3). By 27 months after vaccination, however, only half of the 18 HIV-1-infected children who survived and returned for follow-up maintained measles antibody levels >or=120 mIU/mL, compared with 89% of 71 uninfected children (P=.001) and in contrast with 92% of 12 HIV-1-infected children revaccinated during a supplemental measles immunization activity. CONCLUSIONS: Although HIV-1-infected children showed good primary antibody responses to measles vaccine, their rapid waning of antibody suggests that measles vaccination campaigns may need to be repeated more frequently in areas of high HIV-1 prevalence.