CROI 2016 Abstract eBook
Abstract Listing
Poster Abstracts
737 AreWe Overestimating TB Transmission Among Immigrants and HIV-Positive People? David Stucki 1 ; Marie Ballif 2 ; Kathrin Zürcher 2 ; Matthias Egger 3 ; Sébastien Gagneux 1 ; Lukas Fenner 2 1 Swiss Trop Inst of PH, Basel, Switzerland; 2 Univ of Bern, Bern, Switzerland; 3 Univ Hosp Bern, Bern, Switzerland
Background: Immigration from high tuberculosis (TB) burden regions and HIV infection are major risk factors for TB in low-incidence countries like Switzerland. We have previously analyzed TB transmission using traditional molecular genotyping methods in a nationwide strain collection. Closely related Mycobacterium tuberculosis (Mtb) genotypes, independently imported from regions where they predominate, may lead to an overestimation of recent transmission among immigrants. We used whole genome sequencing (WGS) to analyze transmission clusters in Switzerland with a higher resolution. Methods: We performed WGS on a nationwide collection of 520 Mtb strains isolated in 2000-2008 from HIV-coinfected and HIV-negative TB patients. We defined transmission clusters traditionally as isolates with identical spoligotyping and MIRU-VNTR patterns. We now used WGS data to confirm “true” transmission clusters, defined as isolate pairs separated by a genetic distance of ≤12 single nucleotide polymorphisms (SNP). We used weighted logistic regression adjusted for age, sex, and sputum positivity to identify risk factors for transmission. Results: Only 17/35 (49%) traditionally-defined transmission clusters were confirmed “true” clusters by WGS; the other 18 clusters contained pairs separated by >12 SNPs. Overall, clustering proportion was 17% (90/520 patients, 95% Confidence Interval [CI]: 14-23) using traditional methods, and only 8% (43/520, 95% CI: 7-14) using WGS. Most traditional clusters (75%) involving only Swiss-born individuals were “true” clusters, but only 25% of clusters involving foreign-born patients were confirmed by WGS (Figure). Patients who were HIV-negative (aOR=2.9, 95% CI: 1.2-7.0), male (aOR=2.5, 95% CI: 1.1-5.5) or contact of previous TB cases (aOR=3.1, 95% CI: 1.0-9.6) were more likely to be part of a “true” cluster than others. There was weak evidence for an association between birth countries and transmission (aOR=2.3, 95% CI: 0.9-5.9, comparing Swiss-born patients to others). Conclusions: TB transmission was not more common among immigrants and HIV-positive individuals than others. Traditional genotyping methods lead to an overestimation of recent transmission among foreign-born TB patients, likely due to locally circulating strains independently introduced from TB high-incidence regions. WGS should be applied to identify transmission clusters in low TB incidence settings, particularly in the context of immigration.
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Integrated TB/HIV Services for Migrant Miners and Their Families in Lesotho Andrea A. Howard 1 ; Suzue Saito 1 ; Koen Frederix 1 ;Yael Hirsch-Moverman 2 ; Llang B. Maama 3 ; PheletsoTau 4 ; Kieran Hartsough 1 ; Charles Mugizi 4 ;Wafaa M. El-Sadr 1 1 ICAP at Columbia Univ, New York, NY, USA; 2 Columbia Univ Mailman Sch of PH, New York, NY, USA; 3 Lesotho Ministry of Hlth, Maseru, Lesotho; 4 ICAP at Columbia Univ, Maseru, Lesotho Background: Migrant miners, who travel between home in Lesotho and work in South Africa, are a neglected and hard-to-reach population at high risk of TB and HIV acquisition and transmission. Engagement and retention of miners and their family members along the TB/HIV care continuum are suboptimal, and strategies to improve early diagnosis and treatment outcomes in this high-risk group are urgently needed. Methods: In August 2013 we established on-site TB screening, diagnosis and treatment services within regional offices of an employment agency for miners, in 3 border districts of Lesotho where migrant miners congregate to collect deferred pay. Services initially targeted current miners but were extended to include former miners and miners’ family members due to expressed demand. In September 2014 services were expanded to include on-site opt-out HIV testing and counseling for those with a positive TB symptom screen. We abstracted routinely collected data from clinical registers (Table). Results: Between 8/13 and 2/15, 182,776 persons were screened for TB using a symptom questionnaire. Of these, 8,108 (4.4%) screened positive, of which 6,996 (86%) were tested for TB using on-site Xpert MTB/RIF, and 378 (5.4%) were diagnosed with TB, including 23 (6.1%) with rifampicin-resistant TB. Of 71 TB cases who initiated treatment on-site between 3/14 and 8/14, 57 (80%) completed treatment, compared to treatment success of 63% among miners treated at public clinics. With availability of HIV testing on-site, the proportion of presumptive TB cases with documented HIV status increased from 13% (38/291) in 9/14 to 83% (161/193) in 2/15. Overall 32% of presumptive TB cases without a documented HIV status tested for HIV were HIV+. Of note, 35% of TB cases and 41% of newly diagnosed HIV cases were miners’ family members. A third of family members were male, 19% of whomwere < 25 years old; in contrast >95% of female family members and miners were > 25 years old. Conclusions: On-site integrated TB/HIV services at a mining employment agency in Lesotho enabled efficient TB screening, diagnosis and management and HIV testing for current and former miners and their family members, and reaching young men. High prevalence of undiagnosed TB was found, with high TB treatment completion noted. HIV prevalence was high among miners and their family members. These findings suggest that this non-traditional venue can offer the opportunity to diagnose and manage TB and HIV in this vulnerable and hard-to-reach population.
Poster Abstracts
307
CROI 2016
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