CROI 2016 Abstract eBook

Abstract Listing

Poster Abstracts

787 Diagnostic Accuracy of Cepheid Xpert HIV-1 Qual for Early Infant Diagnosis Sekesai Mtapuri-Zinyowera 1 ; Zibusiso Ndlovu 2 ; Emmanuel Farjado 3 ; Carol Metcalf 3 ; Kekeletso Kao 4 ; Maryam Rumaney 3 ; Elton Mbofana 2 ; Daniel Orozco 4 ; Helen Bygrave 3 1 Natl Microbiology Reference Lab, Harare, Zimbabwe; 2 Médecins Sans Frontières, Harare, Zimbabwe; 3 Médecins Sans Frontières, Southern Africa Med Unit, Cape Town, South Africa; 4 FIND, Geneva, Switzerland Background: Among HIV-exposed infants, delays in early infant diagnosis (EID) result in high morbidity and mortality. The World Health Organization recommends testing of HIV- exposed infants at 6 weeks for EID. In many resource-limited settings, testing is available only in centralized laboratories, resulting in delays in diagnosis. Cepheid recently released Xpert HIV-1 Qual (Xpert), the first near point-of-care test for EID. The diagnostic accuracy of this new test was evaluated in a central laboratory in Harare, Zimbabwe. Methods: Paired testing of dried blood spot samples from 446 HIV-exposed infants and children ≤18 months was performed using Xpert and Roche Cobas AmpliPrep/Cobas TaqMan (Roche), with Roche serving as the comparator. Samples were collected between January and August 2015 and tested in a central laboratory in Harare, Zimbabwe. Archived HIV PCR-positive samples were used to enable sensitivity to be estimated with reasonable precision. Results: Of the pairs of samples tested, 174/446 (39.0%) were positive on Roche. The median age at testing was 6.9 weeks (interquartile range: 6.1 – 15.3 weeks). Of those with information on feeding, 317/403 (78.7%) were breastfed exclusively. The sensitivity of Xpert was 96.0% (95% confidence interval [CI]: 91.9 – 98.4%) and the specificity was 100% (95% CI: 98.7 – 100%). Conclusions: Xpert HIV-1 Qual is a promising test for use at the point of care in resource-limited settings. These findings need to be confirmed by similar studies with decentralized point-of-care testing under conditions of intended use. 788 Point-of-Care p24 Infant Testing May Increase Patient Yield Despite Low Sensitivity Bindiya Meggi 1 ; Nedio Mabunda 1 ; AdolfoVubil 1 ; Osvaldo Loquilha 2 ; Jorge I. Quevedo 3 ; OceanTobaiwa 3 ;Timothy Bollinger 3 ; LaraVojnov 3 ;Trevor Peter 4 ; IleshV. Jani 5 1 Inst Nacional de Saúde de Mocambique, Maputo, Mozambique; 2 Univ Eduardo Mondlane, Maputo, Mozambique; 3 Clinton Hlth Access Initiative, Maputo, Mozambique; 4 Clinton Hlth Access Initiative, Gabarone, Botswana; 5 Inst Nacional de Saude, Maputo, Mozambique Background: Poor access to early infant HIV diagnosis (EID) is a primary cause for the antiretroviral treatment (ART) gap in HIV-infected children. A point-of-care (POC) test for EID may help overcome this challenge by eliminating the need for centralized nucleic acid testing (NAT) and enabling prompt referral to ART. We evaluated the accuracy of a POC p24 HIV Antigen Test in primary health clinics (PHC) in Mozambique and estimated its impact on patient yield. Methods: POC p24 and laboratory-based NAT for EID were conducted in 879 HIV-exposed infants under 18 months of age that were enrolled consecutively at three peri-urban PHC in Maputo City. Lancet-drawn blood specimens were tested on site by nurses using a prototype POC test for p24 antigen detection. The same blood draw was used to create dried

Poster Abstracts

blood spots for laboratory testing. Sensitivity, specificity and predictive values were calculated for the POC assay. The potential impact of the POC assay on patient yield was estimated based on a grid (Figure 1) mapping the intersection of sensitivity and timely result return rates. We used an estimate of 95% for same-day results observed in POC environments and national EID program data indicating 37.6% of results returned within 28 days for standard of care (SOC). Results: The sensitivity and specificity of POC p24 EID testing were 71.9%; (95% confidence interval [CI]: 58.5-83.0%) and 99·6% (95% CI: 98.9-99.9%), respectively. Overall agreement was high (Cohen Kappa = 0·80; 95% CI: 0.71-0.89). Positive 81.2% (95% CI: 72.9-89.5%) and negative 98.8% (95% CI: 98.3- 99.3%) test agreements were also high. The predictive value of a positive test was 93.2% (95% CI: 81.3-98.6%) and the predictive value of a negative test was 97.9% (95% CI: 96.8-98.8%). When compared to SOC, the use of this POC p24 test could link up to 81%more patients to timely care in Mozambique. Return rates of SOC would have to improve to 68.3% before SOC yields would surpass those of this POC test. Conclusions: This prototype p24 assay was feasible for near-to-patient use in PHC but showed a low sensitivity for detecting HIV-infected infants. POC technologies that perform below ideal thresholds may still be valuable diagnostic tools given their potentially significant impact on linkage to care.

789

Malawi’s Option B+ 2011-2015: The Impact of Rapid ART Decentralization Sundeep K. Gupta 1 ; Andreas Jahn 2 ; BethTippett Barr 3 ; James Houston 4 ; Alice Maida 1 ; Jen Sabatier 4 ; Crispin Musicha 1 ; Frank Chimbwandira 5 1 CDC, Lilongwe, Malawi; 2 Univ of Washington, Seattle, WA, USA; 3 CDC, Harare, Zimbabwe; 4 CDC, Atlanta, GA, USA; 5 Malawi Ministry of Hlth, Lilongwe, Malawi Background: In July 2011, Malawi began offering lifelong ART to all HIV-infected pregnant and breastfeeding women, regardless of clinical or immunological stage (Option B+). To scale up this policy, Malawi fully integrated PMTCT and ART services and decentralized services to all facilities. Critical enablers included highly simplified and standardized clinical guidelines aiming to eliminate barriers to ART services at peripheral sites; an established system of quarterly supervision to all sites to ensure basic quality of service and guideline adherence; integrated M&E tools; and nurse-based ART initiation and follow up.

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CROI 2016