CROI 2018 Abstract eBook

Abstract eBook

Poster Abstracts

778 SPATIAL OVERLAP LINKS SEEMINGLY UNCONNECTED GENOTYPE- MATCHED TB CASES IN RURAL UGANDA Gabriel Chamie 1 , Midori Kato-Maeda 1 , Devy Emperador 1 , Bonnie Wandera 2 , John Crandall 3 , Michael Janes 1 , Carina Marquez 1 , Moses R. Kamya 4 , Edwin D. Charlebois 1 , Diane V. Havlir 1 1 University of California San Francisco, San Francisco, CA, USA, 2 Makerere University– University of California San Francisco Research Collaboration, Kampala, Uganda, 3 California Department of Public Health, Richmond, CA, USA, 4 Makerere University, Kampala, Uganda Background: Incomplete understanding of TB transmission in high HIV prevalence settings remains an obstacle for TB prevention efforts. Understanding where TB transmission occurs could provide a platform for optimizing approaches to case finding and interrupt transmission. Methods: From 2012–2015, we sought to recruit all adults (≥18) starting TB treatment in a rural Ugandan community. Participants underwent household (HH) contact investigation, and provided names of frequent social contacts, sites of work, health care and socializing, and 2 sputum samples. Mycobacterium tuberculosis culture-positive (MTB Cx+) specimens underwent 24-loci MIRU- VNTR and spoligotyping to identify genotype-matched strains. We sought to identify epidemiologic links between genotype-matched cases by analyzing social networks and GPS mapping every location where TB cases reported spending ≥12 hours in total over the 1-month pre-treatment. Sites of spatial overlap (≤100m) between genotype-matched cases were considered potential transmission sites. We analyzed social networks stratified by genotype clustering status, with cases linked by shared locations, and compared network density (i.e. proportion of potential network connections that are actual connections) by location type between clustered vs. non-clustered cases. Results: Of 173 adults with TB, 131 (76%) were enrolled, 108 provided sputum, and 84/131 (78%) were MTB Cx+: 52% (66/131) tested HIV positive. Of 118 adult HH contacts, 105 (89%) were screened and 3 (2.5%) newly diagnosed with active TB. Overall, 33 TB cases (39%; 95% CI:29-51%) belonged to 15 distinct MTB genotype-matched clusters. Within each cluster, no cases shared a HH or reported shared non-HH contacts. In 6/15 (40%) clusters, potential epidemiologic links were identified by spatial overlap at specific locations: 5/6 clusters with links based on spatial overlap involved health care settings. Genotype-clustered TB social networks had significantly greater network density based on shared clinics (p<0.001) and decreased density based on shared marketplaces (p<0.001), compared to non-clustered TB networks (Table). Conclusion: In this molecular epidemiologic study, potential epidemiologic links between MTB genotype-matched cases were only identifiable via shared locations, health care locations in particular, rather than named contacts. This suggests most transmission is occurring between casual contacts, and emphasizes the continuing need for improved infection control in health care settings in rural Africa.

and 57% HIV co-infected. We demonstrate a method to enable drug resistant TB monitoring by identifying high-burden communities in the Western Cape Province using routinely collected laboratory data. Methods: We retrospectively identified microbiologically-confirmed and RR-TB cases from all biological samples submitted for TB testing (n=2,219,891) to the Western Cape National Health Laboratory Services (NHLS) between January 2008 and June 2013. As the NHLS database lacks unique patient identifiers, we performed a series of record-linking processes to match specimen records to individual patients. We allowed patients to have multiple episodes of disease but removed those in consecutive years to avoid duplicate counting of the same episode. We aggregated cases by clinic location (n=302) to estimate the proportion of TB cases with rifampicin resistance (“RR-TB proportion”) per clinic. We used inverse distance weighting to produce heat maps of the RR-TB proportion across the province. We used regression to estimate annual changes in the RR-TB proportion by clinic and mapped the estimated average size and direction of change. Results: We identified 799,779 individuals who had specimens submitted from clinics for testing, of whom 222,735 (27.8%) had microbiologically-confirmed TB. The study population was 43% female and median age was 36 years (IQR 27-44). A total of 4.6% (95% CI: 4.6-4.7) of cases were RR (Figure 1). Among individuals with microbiologically-confirmed TB, 8,947 (4.0%) had more than one episode of disease during the study period. The RR-TB proportion among these individuals was 11.4% (95% CI: 10.7-12.0). Overall, the RR-TB proportion was spatially heterogeneous, ranging from 0% to 25% across the province. Our maps revealed significant year-on-year fluctuations in RR-TB proportions at several locations. Additionally, the directions of change in RR-TB proportion were not uniform. Conclusion: Our maps revealed striking spatial and temporal heterogeneity in RR-TB proportions across this province. We demonstrate the potential to monitor RR-TB spatially and temporally with routinely collected laboratory data, enabling improved resource targeting and more rapid locally-appropriate interventions in a high TB and HIV burden setting.

Poster Abstracts

780 TREATING RIFAMPICIN-RESISTANT TB WITH DELAMANID IN A HIGH HIV PREVALENCE SETTING Erika K. Mohr 1 , Anja Reuter 1 , Jennifer Hughes 1 , Justine Fargher 1 , Johnny Daniels 1 , Bongani Chabalala 1 , Gabriella Ferlazzo 1 , Virginia de Azevedo 2 , Amir Shroufi 1 , Laura Trivino Duran 1 , Petros Isaakidis 1 1 MSF, Cape Town, South Africa, 2 City of Cape Town Department of Health, Cape Town, South Africa Background: Delamanid (DLM) was recommended by the World Health Organization in 2014 for the treatment of rifampicin-resistant tuberculosis (RR-TB). Experience with DLM has been limited, particularly among patients with HIV. We aim to describe interim treatment outcomes using DLM in a high HIV burden programmatic setting in Khayelitsha, South Africa. Methods: This was an observational cohort of patients who had DLM started as part of their RR-TB treatment regimen between November 1 2015 and July 31 2017. Participants were followed to September 13, 2017; interim treatment outcomes and sputum culture status at 6 months were described, stratified by HIV status.

779 SPATIAL DISTRIBUTION OF RIFAMPICIN-RESISTANT TB IN WESTERN CAPE, SOUTH AFRICA Avery McIntosh 1 , Helen E. Jenkins 1 , Laura F. White 1 , Elizabeth J. Ragan 2 , Tania Dolby 3 , John Simpson 3 , Megan B. Murray 4 , Rob Warren 5 , Karen R. Jacobson 2 1 Boston University, Boston, MA, USA, 2 Boston Medical Center, Boston, MA, USA, 3 National Health Laboratory Service, Cape Town, South Africa, 4 Harvard University, Cambridge, MA, USA, 5 Stellenbosch University, Tygerberg, South Africa Background: South Africa has the highest tuberculosis (TB) incidence globally (834/100,000), with an estimated 4.3% of cases being rifampicin resistant (RR)

CROI 2018 292