Targeted and whole-genome sequencing reveal a north-south divide in P. falciparum drug resistance markers and genetic structure in Mozambique

Mozambique is one of the four African countries which account for over half of all malaria deaths worldwide, yet little is known about the parasite genetic structure in that country. We performed P. falciparum amplicon and whole genome sequencing on 2251 malaria-infected blood samples collected in 2015 and 2018 in seven provinces of Mozambique to genotype antimalarial resistance markers and interrogate parasite population structure using genome-wide microhaplotyes. Here we show that the only resistance-associated markers observed at frequencies above 5% were pfmdr1-184F (59%), pfdhfr-51I/59 R/108 N (99%) and pfdhps-437G/540E (89%). The frequency of pfdhfr/pfdhps quintuple mutants associated with sulfadoxine-pyrimethamine resistance increased from 80% in 2015 to 89% in 2018 (p < 0.001), with a lower expected heterozygosity and higher relatedness of microhaplotypes surrounding pfdhps mutants than wild-type parasites suggestive of recent selection. pfdhfr/pfdhps quintuple mutants also increased from 72% in the north to 95% in the south (2018; p < 0.001). This resistance gradient was accompanied by a concentration of mutations at pfdhps-436 (17%) in the north, a south-to-north increase in the genetic complexity of P. falciparum infections (p = 0.001) and a microhaplotype signature of regional differentiation. The parasite population structure identified here offers insights to guide antimalarial interventions and epidemiological surveys.

A multi-level examination of the experiences of female sex workers living with HIV along the continuum of care in the Dominican Republic.

Female sex workers (FSWs) are disproportionately affected by HIV, but there is limited research on their HIV care experiences. This study explored the experiences of 44 FSWs living with HIV in Santo Domingo, Dominican Republic along the HIV care continuum using in-depth interviews and focus groups. Data were analysed through narrative and thematic analysis. Individual-level factors that facilitated engagement in HIV care were physical and mental health. At the interpersonal level, disclosure of HIV or sex work status and receipt of emotional and economic support were important influences on engagement. Yet, negative reactions to or lack of disclosure of these statuses compromised engagement, further highlighting the role of stigma and discrimination. At the environmental level, FSWs described considerable challenges with the health system including long waits and treatment stock-outs at their clinics, but were generally satisfied with HIV clinic staff. At the structural level, lack of economic resources complicated care and treatment adherence. Findings underscore the need for psychosocial and economic support tailored to the unique needs of FSWs to maximise the individual and public health benefits of HIV care.

High Drop-off Along the HIV Care Continuum and ART Interruption Among Female Sex Workers in the Dominican Republic.

BACKGROUND: Engagement in HIV care offers clear individual and societal benefits, but little evidence exists on the care experiences of key populations. METHODS: A cross-sectional survey was conducted with 268 female sex workers (FSWs) living with HIV in Santo Domingo, Dominican Republic, to describe the HIV care continuum and to determine factors associated with antiretroviral therapy (ART) interruption. RESULTS: FSWs disengaged throughout the care continuum with the highest drop-off after ART initiation. Most participants were linked to care (92%), retained in care (85%), and initiated onto ART (78%), but ART discontinuation and irregular adherence were frequent. Only 48% of participants had an undetectable HIV viral load. Overall, 36% of participants ever initiated onto ART reported lifetime experience with ART interruption. The odds of ART interruption were 3.24 times higher among women who experienced FSW-related discrimination [95% confidence interval (CI): 1.28 to 8.20], 2.41 times higher among women who used any drug (95% CI: 1.09 to 5.34), and 2.35 times higher among women who worked in an FSW establishment (95% CI: 1.20 to 4.60). Internalized stigma related to FSW was associated with higher odds of interruption (adjusted odds ratio: 1.09; 95% CI: 1.02 to 1.16), and positive perceptions of HIV providers were protective (adjusted odds ratio: 0.91; 95% CI: 0.85 to 0.98). CONCLUSIONS: FSWs living with HIV confront multiple barriers throughout the HIV care continuum, many of which are related to the social context and stigmatization of sex work. Given the clear importance of maximizing the potential benefits of engagement in HIV care, there is an urgent need for interventions to support FSWs throughout the HIV care continuum.

Retention in HIV care among female sex workers in the Dominican Republic: implications for research, policy and programming.

There are clear benefits of retention in HIV care, yet millions of people living with HIV are sub-optimally retained. This study described factors from Andersen's behavioral model that were associated with retention in HIV care among 268 female sex workers (FSWs) living with HIV in the Dominican Republic using two measures of retention: a 6-month measure of HIV clinic attendance and a measure that combined clinic attendance and missed visits. FSWs who ever attended HIV care reported high rates (92 %) of 6-month attendance, but 37 % reported missed visits. Using the combined retention measure, the odds of being retained in HIV care were higher among FSWs with more positive perceptions of HIV service providers [adjusted odds ratio (AOR) 1.17; 95 % confidence interval (CI) 01.09, 1.25] and lower among women who reported recent alcohol consumption (AOR 0.50; 95 % CI 0.28, 0.92) and self-stigmatizing beliefs related to sex work (AOR 0.93; 95 % CI 0.88, 0.98). These findings support the hypothesis that retention in HIV care may be best determined through a combined measure as missed visits are an important mechanism to identify in-care patients who require additional support.