Xpert HIV-1 qual point-of-care testing for HIV early infant diagnosis in Tanzania: experiences and perceptions of health care workers in a 2016 study.

BACKGROUND: HIV early infant diagnosis (HEID) at the centralized laboratory faces many challenges that impact the cascade of timely HEID. Point of Care (PoC) HEID has shown to reduce test turnaround times, allow for task shifting and has the potential to reduce infant mortality. We aimed at assessing the feasibility of nurse based PoC-HEID in five facilities of Mbeya region. METHODS: We analysed data from healthcare workers at five obstetric health facilities that participated in the BABY study which enrolled mothers living with HIV and their HIV exposed infants who were followed up until 6 weeks post-delivery. Nurses and laboratory personnel were trained and performed HEID procedures using the Xpert HIV-1 Qual PoC systems. Involved personnel were interviewed on feasibility, knowledge and competency of procedures and overall impression of the use of HIV-1 Qual PoC system in clinical settings. RESULTS: A total of 28 health care workers (HCWs) who participated in the study between 2014 and 2016 were interviewed, 23 being nurses, 1 clinical officer, 1 lab scientist and 3 lab technicians The median age was 39.5 years. Majority of the nurses (22/24) and all lab staff were confident using Gene Xpert PoC test after being trained. None of them rated Gene Xpert handling as too complicated despite minor challenges. Five HCWs (5/24) reported power cut as the most often occurring problem. As an overall impression, all interviewees agreed on PoC HEID to be used in clinical settings however, about half of them (11/24) indicated that the PoC-HEID procedures add a burden onto their routine workload. CONCLUSION: Overall, health care workers in our study demonstrated very good perceptions and experiences of using PoC HEID. Efforts should be invested on quality training, targeted task distribution at the clinics, continual supportive supervision and power back up mechanisms to make the wide-scale adoption of nurse based PoC HEID testing a possibility.

Accuracy and Operational Characteristics of Xpert Human Immunodeficiency Virus Point-of-Care Testing at Birth and Until Week 6 in Human Immunodeficiency Virus-exposed Neonates in Tanzania.

Background: Point-of-care (PoC) systems for early infant diagnosis (EID) may improve timely infant human immunodeficiency virus (HIV) management. Experiences within African public health settings are limited. Methods: We evaluated the accuracy and operational feasibility of the Xpert HIV-1 Qual for PoC-EID testing, using fresh blood and dried blood spots (DBS) samples at obstetric health facilities in Tanzania at birth and at postpartum weeks 1, 2, 3, and 6 in HIV-exposed infants. Test results were confirmed using TaqMan DBS HIV-deoxyribonucleic acid and/or plasma HIV-ribonucleic acid (RNA) testing. Results: At week 6, 15 (2.5%) out of 614 infants were diagnosed with HIV; 10 (66.7%) of them at birth (median HIV-RNA 4570 copies/mL). At birth, the Xpert-PoC and Xpert-DBS were 100% sensitive (95% confidence intervals: PoC, 69.2-100%; DBS, 66.4-100%) and 100% specific (PoC, 92.1-100%; DBS, 88.4-100%). By week 3, 5 infants with intra/postpartum HIV-infection (median HIV-RNA 1 160 000 copies/mL) were all correctly diagnosed by Xpert. In 2 cases, Xpert-PoC testing correctly identified HIV-infection when DBS tests (Xpert and TaqMan) were negative, suggesting a greater sensitivity. In 2 infants with confirmed HIV at birth, all tests were negative at week 6, possibly because of viral suppression under nevirapine prophylaxis. Problems were reported in 183/2736 (6.7%) of Xpert-PoC tests, mostly related to power cuts (57.9%). Conclusions: We demonstrated excellent Xpert HIV-1 Qual performance and good operational feasibility for PoC-EID testing at obstetric health facilities. Week 6 sensitivity issues were possibly related to nevirapine prophylaxis, supporting additional birth PoC-EID testing to avoid underdiagnosis. Clinical Trials Registration: NCT02545296.

Prevalence of and risk factors associated with HIV, Herpes Simplex Virus-type 2, Chlamydia trachomatis and Neisseria gonorrhoeae infections among 18-24 year old students attending Higher Learning Institutions in Mbeya-Tanzania.

BACKGROUND: Sexually transmitted infections (STIs) are common among young people in low- and middle-income countries and are associated with negative reproductive and pregnancy outcomes. Most of the studies have assessed HIV among adolescents and young adults, with limited information on occurrence of other STIs in this population. This study aimed to describe the prevalence of and risk factors associated with Herpes Simplex Virus-type 2 (HSV-2), Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Syphilis and HIV infection among young adults attending Higher Learning Institutions (HLIs) in Mbeya, Tanzania. METHODS: We conducted a cross-sectional study among students aged 18-24years attending HLIs in Mbeya-Tanzania, randomly selected using a computerized random number. Participants were tested for HSV-2, CT, NG, Syphilis and HIV infection. We used a self-administered questionnaire to collect information on sexual activity and risk factors to the tested STIs. RESULTS: We enrolled 504 students from 5 HLIs, with mean age of 21.5 years (SD 1.7). 17% of the students had at least one STI; prevalence was higher among females than males (21.1% versus 14.1%). CT (11%) and HSV-2 (6.1%) were the most common STIs, while NG (1.1%) and HIV (0.7%) infection had the least occurrence. None of the participants was diagnosed with Syphilis. In univariate analysis, predictors for STIs were Sex, inconsistent condom use in the past 4weeks, report of oral sex, sexual orientation (bisexual/homosexual) and having a sexual partner with an age-difference of at least 5years (either older or younger); while in the multivariate analysis, Sex, inconsistent condom use in the past 4weeks and sexual orientation (bisexual/homosexual) remained significant. CONCLUSION: STIs such as Chlamydia and HSV-2 which are commonly asymptomatic are of concern among young adults attending HLIs. The latter is an important group that needs attention and recognition that is pivotal in transmission of STIs considering their risk. Information, Education and Communication (IEC) campaigns targeting young adults, especially those at HLIs, need to focus on exposure-risk minimization. Funding institutions that have invested heavily on HIV prevention campaigns should consider giving similar recognition to other STIs for a streamlined outcome.

A high viral burden predicts the loss of CD8 T-cell responses specific for subdominant gag epitopes during chronic human immunodeficiency virus infection.

Human immunodeficiency virus (HIV)-specific CD8 T-cell responses targeting products encoded within the Gag open reading frame have frequently been associated with better viral control and disease outcome during the chronic phase of HIV infection. To further clarify this relationship, we have studied the dynamics of Gag-specific CD8 T-cell responses in relation to plasma viral load and time since infection in 33 chronically infected subjects over a 9-month period. High baseline viral loads were associated with a net loss of breadth (P < 0.001) and a decrease in the total magnitude of the Gag-specific T-cell response in general (P = 0.03). Most importantly, the baseline viral load predicted the subsequent change in the breadth of Gag recognition over time (P < 0.0001, r(2) = 0.41). Compared to maintained responses, lost responses were low in magnitude (P < 0.0001) and subdominant in the hierarchy of Gag-specific responses. The present study indicates that chronic exposure of the human immune system to high levels of HIV viremia is a determinant of virus-specific CD8 T-cell loss.

CD8 T-cell recognition of multiple epitopes within specific Gag regions is associated with maintenance of a low steady-state viremia in human immunodeficiency virus type 1-seropositive patients.

The importance of HLA class I-restricted CD8 T-cell responses in the control of human immunodeficiency virus (HIV) infection is generally accepted. While several studies have shown an association of certain HLA class I alleles with slower disease progression, it is not fully established whether this effect is mediated by HIV-specific CD8 T-cell responses restricted by these alleles. In order to study the influence of the HLA class I alleles on the HIV-specific CD8 T-cell response and on viral control, we have assessed HIV-specific epitope recognition, plasma viral load, and expression of HLA class I alleles in a cohort of HIV-seropositive bar workers. Possession of the HLA class I alleles B5801, B8101, and B0702 was associated with a low median viral load and simultaneously with a broader median recognition of Gag epitopes compared to all other HLA alleles (twofold increase) (P = 0.0035). We further found an inverse linear relationship between the number of Gag epitopes recognized and the plasma viral load (R = -0.36; P = 0.0016). Particularly, recognition of multiple epitopes within two regions of Gag (amino acids [aa] 1 to 75 and aa 248 to 500) was associated with the maintenance of a low steady-state viremia, even years after acute infection.