Most human immunodeficiency virus type 1 (HIV-1) transmissions in sub-Saharan Africa are believed to occur between married adults who are discordant for their HIV-1 infection status; however, no studies to date have investigated the molecular epidemiology of such transmission events. Here we report the genetic characterization of HIV-1 strains from 149 transmission pairs that were identified prospectively in a cohort of discordant couples in Lusaka, Zambia. Subgenomic gag, gp120, gp41, and/or long terminal repeat regions were amplified by PCR analysis of uncultured blood samples from both partners and sequenced without interim cloning. Pairwise genetic distances were calculated for the regions analyzed and compared to those of subtype-specific reference sequences as well as local controls. Sequence relationships were also examined by phylogenetic tree analysis. By these approaches, epidemiological linkage was established for the majority of transmission pairs. Viruses from 129 of the 149 couples (87%) were very closely related and clustered together in phylogenetic trees in a statistically highly significant manner. In contrast, viruses from 20 of the 149 couples (13%) were only distantly related in two independent genomic regions, thus ruling out transmission between the two partners. The great majority (95%) of transmitted viruses were of subtype C origin, although representatives of subtypes A, D, G, and J were also identified. There was no evidence for extensive transmission networks within the cohort, although two phylogenetic subclusters of viruses infecting two couples each were identified. Taken together, these data indicate that molecular epidemiological analyses of presumed transmission pairs are both feasible and required to determine behavioral, virological, and immunological correlates of heterosexual transmission in sub-Saharan Africa with a high level of accuracy.

Molecular epidemiology of human immunodeficiency virus type 1 transmission in a heterosexual cohort of discordant couples in Zambia.

Objective To find out why pregnant women who receive HIV-1 positive test results and are offered short course antiretroviral prophylaxis to prevent transmission of HIV from mother to child do not participate in necessary follow up visits before starting prophylaxis. Design Qualitative interview study. Setting A programme aiming to prevent transmission of HIV from mother to child at a public antenatal clinic in Abidjan, Cote d9Ivoire. Participants Purposive sample of 27 women who had received HIV-1 positive test results and were invited to return for monthly follow up visits before starting prophylaxis with zidovudine at 36 weeks9 gestation, but who had either refused or discontinued the visits. None of the women started prophylaxis. Results Most of the women explained their non-participation in follow up visits by referring to negative experiences that they had had while interacting with programme staff or to their views about the programme. Additional reasons concerned their disbelief of HIV positive test results and personal factors. Conclusions Difficulties experienced by women during their contacts with staff working on the prevention programme and negative views that they have about the programme can contribute to their non-participation in prophylaxis. Training and supervision of programme staff may increase the likelihood of positive interactions between staff and clients, thereby facilitating women9s participation in preventing transmission of HIV from mother to child. Outreach and mobilisation in communities that are served by prevention programmes may complement these measures at programme level by contributing to increased social support for women9s efforts to prevent transmission of HIV from mother to child.

Women's reasons for not participating in follow up visits before starting short course antiretroviral prophylaxis for prevention of mother to child transmission of HIV: qualitative interview study

We describe promotional strategies for couples voluntary HIV counseling and testing (CVCT) and demographic risk factors for couples in Lusaka Zambia where an estimated two thirds of new infections occur in cohabiting couples. CVCT attendance as a function of promotional strategies is described over a 6-year period. Cross-sectional analyses of risk factors associated with HIV in men women and couples are presented. Community workers (CWs) recruited from couples seeking CVCT promoted testing in their communities. Attendance dropped when CW outreach ended despite continued mass media advertisements. In Lusaka 51% of 8500 cohabiting couples who sought HIV testing were concordant negative for HIV (M-F-) and 26% concordant positive (M+F+); 23% had 1 HIV-positive partner and one HIV-negative partner with 11% HIV-positive man/HIV-negative woman (M+F-) and 12% HIV-negative man/HIV-positive woman (F+M-). HIV infection was associated with mens age 30 to 39 womens age 25 to 34 duration of union < 3 years and number of children < 2. Even among couples with either 1 or 2 or no risk factors HIV prevalence was 45% and 29% respectively. Many married African adults do not have high-risk profiles nor realize that only 1 may be HIV positive. Active and sustained promotion is needed to encourage all couples to be jointly tested and counseled. (authors)

Evolution of couples' voluntary counseling and testing for HIV in Lusaka, Zambia.

Voluntary testing and counseling (VTC) for HIV/AIDS is now widely accepted as an effective HIV prevention and control strategy among heterosexual couples in sub-Saharan Africa. The most appropriate format and venue for VTC remains a topic of debate among clinicians and public health professionals. Our research done in Lusaka, Zambia, took a tripartite approach to exploring the most acceptable format and venue for VTC: a community survey of attitudes towards VTC, a pre- and postcounseling knowledge survey, and a pilot study of same-day VTC in urban antenatal care clinics. A community survey of 181 individuals was conducted in July-August 1996 based on a structured questionnaire. A pre- and post-VTC intervention knowledge survey was conducted during the same period among 82 couples attending the Zambia-UAB HIV Research Project (ZUHRP) HIV VTC center in Lusaka. Finally, same-day HIV VTC was pilot tested in six antenatal clinic locations during February-May 1997 and June-August 1998. The community survey revealed that 98% of participants support promotion of HIV VTC in the community and 83.8% prefer the same-day testing format. The knowledge survey revealed misconceptions about discordance within a couple and perinatal transmission of HIV. Pilot testing in antenatal clinics was well received, with 84% of pregnant women requesting testing and 25% having positive HIV serologies. Women with primary school or less education, those seeking antenatal care in local clinics, and those seen before the third trimester of pregnancy were more likely to request HIV testing. Testing and counseling for HIV were shown to be feasible and effective in the antenatal clinic setting. Implementation of same-day HIV VTC in antenatal clinics is an effective strategy to prevent vertical transmission and should be expanded to include couples to leverage a decrease in heterosexual transmission as well.

Rapid Voluntary Testing and Counseling for HIV: Acceptability and Feasibility in Zambian Antenatal Care Clinics

With the accessibility of prevention of mother to child transmission (PMTCT) services in sub-Saharan Africa, more women are being tested for HIV in antenatal care settings. Involving partners in the counselling and testing process could help prevent horizontal and vertical transmission of HIV. This study was conducted to assess the feasibility of couples' voluntary counseling and testing (CVCT) in antenatal care and to measure compliance with PMTCT. A prospective cohort study was conducted over eight months at two public antenatal clinics in Kigali, Rwanda, and Lusaka, Zambia. A convenience sample of 3625 pregnant women was enrolled. Of these, 1054 women were lost to follow up. The intervention consisted of same-day individual voluntary counselling and testing (VCT) and weekend CVCT; HIV-positive participants received nevirapine tablets. In Kigali, nevirapine syrup was provided in the labour and delivery ward; in Lusaka, nevirapine syrup was supplied in pre-measured single-dose syringes. The main outcome measures were nurse midwife-recorded deliveries and reported nevirapine use. In eight months, 1940 women enrolled in Kigali (984 VCT, 956 CVCT) and 1685 women enrolled in Lusaka (1022 VCT, 663 CVCT). HIV prevalence was 14% in Kigali, and 27% in Lusaka. Loss to follow up was more common in Kigali than Lusaka (33% vs. 24%, p = 0.000). In Lusaka, HIV-positive and HIV-negative women had significantly different loss-to-follow-up rates (30% vs. 22%, p = 0.002). CVCT was associated with reduced loss to follow up: in Kigali, 31% of couples versus 36% of women testing alone (p = 0.011); and in Lusaka, 22% of couples versus 25% of women testing alone (p = 0.137). Among HIV-positive women with follow up, CVCT had no impact on nevirapine use (86-89% in Kigali; 78-79% in Lusaka). Weekend CVCT, though new, was feasible in both capital cities. The beneficial impact of CVCT on loss to follow up was significant, while nevirapine compliance was similar in women tested alone or with their partners. Pre-measured nevirapine syrup syringes provided flexibility to HIV-positive mothers in Lusaka, but may have contributed to study loss to follow up. These two prevention interventions remain a challenge, with CVCT still operating without supportive government policy in Zambia.

/pdf/couples-voluntary-counselling-and-testing-and-nevirapine-use-5cb1c7ixbc.pdf

Couples' voluntary counselling and testing and nevirapine use in antenatal clinics in two African capitals: a prospective cohort study

The process known as "voluntary HIV testing and counseling" (VTC) resulted from the recommendation that voluntary HIV antibody testing should be accompanied by explanations emotional support and practical recommendations. It aims to stop the spread of HIV and limit its impact with the emphasis depending on the target population the program providing the service and the population served. The efficacy of VTC in promoting risk reduction needs to be evaluated and compared to other types of ongoing or potential interventions. When successful services should be expanded and promoted in the groups that benefit most from the impact on risk reduction. Where VTC is shown to be effective management and financial issues including cost-recovery should be explored with a pilot voluntary counseling and testing center. VTC is already available in many developing countries in Africa Central and South America and Asia.

The Evolution of Voluntary Testing and Counseling as an HIV Prevention Strategy

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Nicholas N’gandu

Author Tools

Chat about Author

Papers

The Evolution of Voluntary Testing and Counseling as an HIV Prevention Strategy