Spatiotemporal and meteorological relationships in dengue transmission in the Dominican Republic, 2015-2019.

Dengue has broadened its global distribution substantially in the past two decades, and many endemic areas are experiencing increases in incidence. The Dominican Republic recently experienced its two largest outbreaks to date with 16,836 reported cases in 2015 and 20,123 reported cases in 2019. With continued increases in dengue transmission, developing tools to better prepare healthcare systems and mosquito control agencies is of critical importance. Before such tools can be developed, however, we must first better understand potential drivers of dengue transmission. To that end, we focus in this paper on determining relationships between climate variables and dengue transmission with an emphasis on eight provinces and the capital city of the Dominican Republic in the period 2015-2019. We present summary statistics for dengue cases, temperature, precipitation, and relative humidity in this period, and we conduct an analysis of correlated lags between climate variables and dengue cases as well as correlated lags among dengue cases in each of the nine locations. We find that the southwestern province of Barahona had the largest dengue incidence in both 2015 and 2019. Among all climate variables considered, lags between relative humidity variables and dengue cases were the most frequently correlated. We found that most locations had significant correlations with cases in other locations at lags of zero weeks. These results can be used to improve predictive models of dengue transmission in the country.

Will more sensitive diagnostics identify tuberculosis missed by clinicians? Evaluating Xpert MTB/RIF testing in Guatemala / ¿Pueden las pruebas diagnósticas más sensibles identificar los casos de tuberculosis que se escapan a los clínicos? Evaluación de Xpert MIB/RIF en Guatemala

OBJECTIVE: To assess the impact of introducing Xpert as a follow-on test after smear microscopy on the total number pulmonary TB notifications. METHOD: Genexpert systems were installed in six departments across Guatemala, and Xpert was indicated as a follow-on test for people with smear-negative results. We analyzed notifications to national tuberculosis (TB) programmes (NTP) and the project's laboratory data to assess coverage of the intervention and case detection yield. Changes in quarterly TB notifications were analyzed using a simple pre/post comparison and a regression model controlling for secular notification trends. Using a mix of project and NTP data we estimated the theoretical yield of the intervention if testing coverage achieved 100%. RESULTS: Over 18,000 smear-negative individuals were eligible for Xpert testing during the intervention period. Seven thousand, one hundred and ninety-three people (39.6% of those eligible) were tested on Xpert resulting in the detection of 199 people with smear-negative, Xpert positive results (2.8% positivity rate). In the year before testing began 1098 people with smear positive and 195 people with smear negative results were notified in the six intervention departments. During the intervention, smear-positive notification remained roughly stable (1090 individuals, 0.7%), but smear-negative notifications increased by 167 individuals (85.6%) to an all-time high of 362. After controlling for secular notifications trends over an eight-quarter pre-intervention period, combined pulmonary TB notifications (both smear positive and negative) were 19% higher than trend predictions. If Xpert testing coverage approached 100% of those eligible, we estimate there would have been a+41% increase in TB notifications. CONCLUSIONS: We measured a large gain in pulmonary notifications through the introduction of Xpert testing alone. This indicates a large number of people with TB in Guatemala are seeking health care and being tested, yet are not diagnosed or treated because they lack bacteriological confirmation. Wider use of more sensitive TB diagnostics and/or improvements in the number of people clinically diagnosed with TB have the potential to significantly increase TB notifications in this setting, and potentially in other settings where a low proportion of pulmonary notifications are clinically diagnosed

OBJETIVO: Evaluar el impacto en la notificación de casos de tuberculosis pulmonar de la introducción de Xpert como prueba de continuación después del análisis microscópico. MÉTODO: Se instalaron sistemas Genexpert es seis departamentos de Guatemala y se indicó como prueba consecutiva en todos los resultados negativos en la baciloscopia microscópica. Se analizaron los datos del Programa Nacional y los del laboratorio del proyecto para medir la cobertura y la productividad en detección de casos. Las notificaciones trimestrales se compararon con los valores anteriores a la intervención y se adoptó un modelo de regresión para controlar por las tendencias temporales. Se estimó la contribución teórica de la intervención en términos de notificación si se obtuviera una cobertura del 100%. RESULTADOS: Durante el período de intervención, más de 18.000 personas con baciloscopia negativa fueron elegibles en los seis departamentos. El esputo de 7193 (36,9%) de ellos fue analizado también por Xpert y se detectaron 199 personas con baciloscopia negativa y Xpert positivo (positividad: 2,8%). En el año anterior a la intervención se notificaron 1098 casos de tuberculosis pulmonar y baciloscopia positiva, y 195 con baciloscopia negativa. Durante la intervención, la notificación de casos con baciloscopia positiva se mantuvo estable (1090 personas, 0,7%), pero las notificaciones con baciloscopia negativa, que incluía los casos con baciloscopia negativa y Xpert positivo, aumentó en 167 casos (85,6%), llegando a los 362 casos. Después de controlar por la tendencia temporal de notificación en los ocho trimestres anteriores, la notificación de tuberculosis pulmonar (con baciloscopia positiva o no) fue un 19% mayor que las predicciones de la tendencia. Si la cobertura de Xpert se acercase al 100%, se estima que se habría producido un incremento del 41% en las notificaciones. CONCLUSIONES: Se identifica un importante aumento de las notificaciones de tuberculosis pulmonar solo con la introducción de Xpert. Ello indica que un número importante de personas con tuberculosis en Guatemala son atendidos por los servicios de salud y son sometidos a bacteriología microscópica, pero no son diagnosticados ni tratados porque no disponen de confirmación bacteriológica. La utilización de técnicas diagnósticas más sensibles o la mejora en el diagnóstico clínico tienen potencial para aumentar significativamente las notificaciones de tuberculosis pulmonar en esta zona y en cualquier otro lugar donde exista una proporción baja de diagnósticos clínicos no confirmados por microscopía

Will more sensitive diagnostics identify tuberculosis missed by clinicians? Evaluating Xpert MTB/RIF testing in Guatemala.

OBJECTIVE: To assess the impact of introducing Xpert as a follow-on test after smear microscopy on the total number pulmonary TB notifications. METHOD: Genexpert systems were installed in six departments across Guatemala, and Xpert was indicated as a follow-on test for people with smear-negative results. We analyzed notifications to national tuberculosis (TB) programmes (NTP) and the project's laboratory data to assess coverage of the intervention and case detection yield. Changes in quarterly TB notifications were analyzed using a simple pre/post comparison and a regression model controlling for secular notification trends. Using a mix of project and NTP data we estimated the theoretical yield of the intervention if testing coverage achieved 100%. RESULTS: Over 18,000 smear-negative individuals were eligible for Xpert testing during the intervention period. Seven thousand, one hundred and ninety-three people (39.6% of those eligible) were tested on Xpert resulting in the detection of 199 people with smear-negative, Xpert positive results (2.8% positivity rate). In the year before testing began 1098 people with smear positive and 195 people with smear negative results were notified in the six intervention departments. During the intervention, smear-positive notification remained roughly stable (1090 individuals, 0.7%), but smear-negative notifications increased by 167 individuals (85.6%) to an all-time high of 362. After controlling for secular notifications trends over an eight-quarter pre-intervention period, combined pulmonary TB notifications (both smear positive and negative) were 19% higher than trend predictions. If Xpert testing coverage approached 100% of those eligible, we estimate there would have been a+41% increase in TB notifications. CONCLUSIONS: We measured a large gain in pulmonary notifications through the introduction of Xpert testing alone. This indicates a large number of people with TB in Guatemala are seeking health care and being tested, yet are not diagnosed or treated because they lack bacteriological confirmation. Wider use of more sensitive TB diagnostics and/or improvements in the number of people clinically diagnosed with TB have the potential to significantly increase TB notifications in this setting, and potentially in other settings where a low proportion of pulmonary notifications are clinically diagnosed.

Migration, Multiple Sexual Partnerships, and Sexual Concurrency in the Garífuna Population of Honduras.

The Garífuna, an ethnic minority group in Honduras, have been disproportionately affected by HIV. Previous research suggests that migration and high rates of multiple sexual partnerships are major drivers of the epidemic. Using data from a 2012 population-based survey, we assessed whether temporary migration was associated with (1) multiple sexual partnerships and (2) sexual concurrency among Garífuna men and women in Honduras. Among both men and women, temporary migration in the last year was associated with an increased likelihood of multiple sexual partnerships and with concurrency, though only the association between migration and multiple sexual partnerships among men was statistically significant (Adjusted Prevalence Ratio 1.7, 95 % CI 1.2-2.4). Migration may contribute to HIV/STI vulnerability among Garífuna men and women via increases in these sexual risk behaviors. Research conducted among men and women at elevated risk of HIV should continue to incorporate measures of mobility, including history of internal migration.

Evidence of the negative effect of sexual minority stigma on HIV testing among MSM and transgender women in San Salvador, El Salvador.

A cross sectional survey was administered to 670 men who have sex with men (MSM) and transgender women (TW) in San Salvador through respondent driven sampling to identify determinants of ever testing for HIV using a minority stress framework. A positive association was found between ever testing and older age [adjusted odds ratio (aOR) 2.10], past experience of sexual assault (aOR 2.92), perceiving that most social acquaintances had tested (aOR 1.81), and knowing a PLHIV (aOR 1.94). A negative association was found between homelessness and ever testing (aOR 0.43). Among the MSM sub-sample (n = 506), similar results were found for older age (aOR 2.63), and past experience of sexual assault (aOR 2.56). Internalized homonegativity was negatively associated with ever testing for HIV among MSM (aOR 0.46), and HIV testing stigma and experienced provider discrimination further strengthened this relationship. It is important to mitigate sexual minority stigma in order to increase HIV testing among MSM. Future research should explore this construct among TW.

Social network-based recruitment successfully reveals HIV-1 transmission networks among high-risk individuals in El Salvador.

OBJECTIVE: HIV in Central America is concentrated among certain groups such as men who have sex with men (MSM) and female sex workers (FSWs). We compared social recruitment chains and HIV transmission clusters from 699 MSM and 787 FSWs to better understand factors contributing to ongoing HIV transmission in El Salvador. METHODS: Phylogenies were reconstructed using pol sequences from 119 HIV-positive individuals recruited by respondent-driven sampling (RDS) and compared with RDS chains in 3 cities in El Salvador. Transmission clusters with a mean pairwise genetic distance ≤ 0.015 and Bayesian posterior probabilities =1 were identified. Factors associated with cluster membership were evaluated among MSM. RESULTS: Sequences from 34 (43%) MSM and 4 (10%) FSW grouped in 14 transmission clusters. Clusters were defined by risk group (12 MSM clusters) and geographic residence (only 1 spanned separate cities). In 4 MSM clusters (all n = 2), individuals were also members of the same RDS chain, but only 2 had members directly linked through recruitment. All large clusters (n ≥ 3) spanned >1 RDS chain. Among MSM, factors independently associated with cluster membership included recent infection by BED assay (P = 0.02), sex with stable male partners (P = 0.02), and sex with ≥ 3 male partners in the past year (P = 0.04). CONCLUSIONS: We found few HIV transmissions corresponding directly with the social recruitment. However, we identified clustering in nearly one-half of MSM suggesting that RDS recruitment was indirectly but successfully uncovering transmission networks, particularly among recent infections. Interrogating RDS chains with phylogenetic analyses may help refine methods for identifying transmission clusters.

Correlates of bisexual behaviors among men who have sex with men in El Salvador.

Bisexual behaviors may increase transmission pathways of HIV and sexually transmitted infections (STIs) from a higher prevalence group to lower prevalence groups in El Salvador. In 2008, men who have sex with men (MSM) were recruited in San Salvador and San Miguel using respondent driven sampling. Participants were interviewed and tested for HIV and STIs. Sixteen seeds and 797 MSM participated; 34.9% in San Salvador and 58.8% in San Miguel reported bisexual behavior. Bisexual behavior was associated with drug use (adjusted odds ratio (AOR) = 2.57, 95% CI: 1.30-5.06) and insertive anal sex (AOR = 5.45, 95% CI: 3.01-9.87), and inversely associated with having a stable male partner (AOR = 0.47, 95% CI: 0.26-0.84) and disclosing MSM behavior to family (AOR = 0.41, 95% CI: 0.22-0.75). Bisexual behavior was associated with risk behaviors with male and female partners that may be associated with HIV and STI transmission. Bisexual men displayed a distinct identity calling for tailored interventions.

Coverage of HIV prevention components among people with long-standing diagnosed HIV infection in El Salvador.

BACKGROUND: There is scarce information on prevention coverage and management of sexually transmitted infections (STIs) in people with HIV in resource-limited settings. METHODS: Six hundred eighty nine sexually active people diagnosed with HIV ≥12 months before the study, including 110 men who have sex with men, 237 heterosexual men, and 342 women, were recruited from HIV support groups and hospitals in El Salvador and completed self-administered computer-assisted questionnaires and STI testing. Logistic models identified correlates of exposure to posttest counseling (POC) and subsequent prevention interventions (PIs). RESULTS: Past-year transmission risk factors included unprotected sex with noncommercial partners (28.7%), having multiple sex partners (76.4%), a casual sex partner (31.4%), selling (3.5%) and purchasing sex (6.4%), herpes simplex virus type 2 (86.3%), and treatable STIs (18.6%). Men who have sex with men reported more recent casual partners, sex work, and alcohol and drug use than other subgroups. POC (22.8%), PIs (31.3%), and access to advice and information regarding HIV at the point of HIV care (24.1%) were limited. Of subjects with past-year STI symptoms (N = 267), 44.1% had sought medical attention. In multivariate analysis, POC was negatively associated with multiple partners. PI was associated with self-initiated testing, treatable STIs, and female sex. Both outcomes were associated with HIV-related discrimination outside of the health services context. CONCLUSIONS: Coverage of POC, PIs, and treatment-seeking for STI symptoms was low among individuals with diagnosed HIV infection, although most were in regular contact with care and treatment. Prevention programs at testing and treatment sites should be intensified and should incorporate risk behavior screening to improve targeting.

Prevalence of transmitted HIV-1 drug resistance among female sex workers and men who have sex with men in El Salvador, Central America.

Transmitted drug resistance has important implications for the successful use and management of therapy among persons infected with HIV. We estimated the prevalence of transmitted drug resistance in 145 samples from female sex workers (n = 47) and men who have sex with men (n = 98) in El Salvador. Samples were collected during March to September 2008, using a respondent driven sampling. The HIV-1 pol gene was sequenced to identify drug resistance mutations and transmitted drug resistance was scored as recommended by World Health Organization. Specimens were classified as recent or established infections using the Immunoglobulin G-Capture BED-Enzyme Immunoassay. The overall prevalence of transmitted drug resistance was 9.4% (95% CI: 4.7-16.1%), and was 5.9% for non-nucleoside reverse transcriptase inhibitors, 4.2% for nucleoside reverse transcriptase inhibitors, and 0.8% for protease inhibitors. Transmitted drug resistance prevalence was 10.3% (95% CI: 2.8-24.2%) among female sex workers, and 9.0% (95% CI: 3.6-17.6%) among men who have sex with men. Nineteen patients were classified as having recent infection (16.2%, 95% CI: 10.1-24.2%), while 98 patients (83.8%, 95% CI: 75.8-89.9%) were classified as having established infections. Transmitted drug resistance among recent and established infections was similar at 10.5% and 9.2%, respectively. This study shows that the prevalence of transmitted drug resistance is moderate among female sex workers and men who have sex with men in El Salvador. These results highlight the importance of transmitted drug resistance surveillance in a representative sample of recently infected patients following the World Health Organization guidelines.

HIV and STI control in El Salvador: results from an integrated behavioural survey among men who have sex with men.

OBJECTIVE: This cross-sectional study investigates HIV, other sexually transmitted infections (STI), and risk behaviours among men who have sex with men (MSM) in two cities in El Salvador. METHODS: Respondent-driven sampling (RDS) was used to recruit MSM in the cities of San Salvador and San Miguel, El Salvador. Participants responded to questions about HIV risk behaviours; and blood, urine and anal swabs were collected. Blood samples were tested for herpes simplex type 2, syphilis and HIV infection. Urine and anal samples were tested by polymerase chain reaction (PCR) for Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium. HIV-positive samples were tested with the BED capture enzyme immunoassay to distinguish recent from longstanding HIV infection. We estimated population-adjusted prevalence of behavioural variables, STI and HIV, and identified risk factors for HIV. RESULTS: The final sample included 596 and 195 MSM in San Salvador and San Miguel, respectively. Consistent condom use was low across all partner types as was recent HIV testing. RDS-adjusted HIV prevalence was 10.8% (95% CI 7.4% to 14.7%) in San Salvador, and 8.8% (95% CI 4.2% to 14.5%) in San Miguel. The proportion of recent testing among HIV-positive samples was 20%. Prevalence of any bacterial STI by PRC testing was 12.7% (95% CI 8.2% to 17.5%) in San Salvador, and 9.6% (95% CI 4.9% to 15.4%) in San Miguel. CONCLUSIONS: We found a high prevalence of HIV, high levels of recent infection, and low condom usage. In El Salvador, targeted interventions towards MSM are needed to promote condom use, as well as to diagnose, treat and prevent HIV and other STIs.

Social network characteristics and HIV vulnerability among transgender persons in San Salvador: identifying opportunities for HIV prevention strategies.

The purpose of this study is to improve understanding of HIV vulnerability and opportunities for HIV prevention within the social networks of male-to-female transgender persons in San Salvador, El Salvador. We compare HIV prevalence and behavioral data from a sample of gay-identified men who have sex with men (MSM) (n = 279), heterosexual or bisexual identified MSM (n = 229) and transgender persons (n = 67) recruited using Respondent Driven Sampling. Transgender persons consistently reported higher rates of HIV risk behavior than the rest of the study population and were significantly more likely to be involved in sex work. While transgender persons reported the highest rates of exposure to HIV educational activities they had the lowest levels of HIV-related knowledge. Transgender respondents' social networks were homophilous and efficient at recruiting other transgender persons. Findings suggest that transgender social networks could provide an effective and culturally relevant opportunity for HIV prevention efforts in this vulnerable population.

Improving cervical cancer prevention in a developing country.

OBJECTIVE: to enhance the delivery of services, using continuous quality improvement, and an outreach strategy. DESIGN AND SETTING: pre and post measurements in a Primary Health Care system in El Salvador. Outcome indicators: women screened for the first time in their lifetime, unsatisfactory samples, turnaround time, and follow-up. INTERVENTION: involvement of policy, service provision and community levels in 4 plan-do-study-act cycles, facilitating linkages between work processes and a quality control group. RESULTS: 3,408 women screened for the first time in their lifetime in 1 year in regular services; unsatisfactory samples reduced by 1/2; turnaround time reduced by almost 1/3; follow-up increased from 24% (22/90) to 100% (196/196) .146 of the 151 women cytologically defined as low and high-grade squamous intraepithelial lesions (L-HSIL) were confirmed on histology as cervical intraepithelial neoplasia (CIN), while 5 showed benign changes. Of the 43 women classified as having high-grade squamous intraepithelial lesion on cytology, 36 were diagnosed with CIN2 lesions, 7 with CIN3 and 2 were confirmed with invasive carcinoma. CONCLUSION: improvements in delivery of screening can be made with few additional resources in the absence of an organized system. We promoted linkages between detection and diagnosis through enhancement of teamwork and functional coordination, which improved follow-up rates. We restored links between screening and reading processes through minor adjustments, which improved the turnaround time of samples. Trained outreach workers created new links between community and health services, identifying women who had never been screened before in their lives and facilitating their access to regular clinic services.