Genetic and epidemiological description of an outbreak of circulating vaccine-derived polio-virus type 2 (cVDPV2) in Angola, 2019-2020.

After six years without any detection of poliomyelitis cases, Angola reported a case of circulating vaccine-derived poliovirus type 2 (cVDPV2) with paralysis onset date of 27 March 2019. Ultimately, 141 cVDPV2 polio cases were reported in all 18 provinces in 2019-2020, with particularly large hotspots in the south-central provinces of Luanda, Cuanza Sul, and Huambo. Most cases were reported from August to December 2019, with a peak of 15 cases in October 2019. These cases were classified into five distinct genetic emergences (emergence groups) and have ties with cases identified in 2017-2018 in the Democratic Republic of Congo. From June 2019 to July 2020, the Angola Ministry of Health and partners conducted 30 supplementary immunization activity (SIA) rounds as part of 10 campaign groups, using monovalent OPV type 2 (mOPV2). There were Sabin 2 vaccine strain detections in the environmental (sewage) samples taken after mOPV2 SIAs in each province. Following the initial response, additional cVDPV2 polio cases occurred in other provinces. However, the national surveillance system did not detect any new cVDPV2 polio cases after 9 February 2020. While reporting subpar indicator performance in epidemiological surveillance, the laboratory and environmental data as of May 2021 strongly suggest that Angola successfully interrupted transmission of cVDPV2 early in 2020. Additionally, the COVID-19 pandemic did not allow a formal Outbreak Response Assessment (OBRA). Improving the sensitivity of the surveillance system and the completeness of AFP case investigations will be vital to promptly detect and interrupt viral transmission if a new case or sewage isolate are identified in Angola or central Africa.

Immunity to poliovirus in Afghanistan: A household sampling method for serological assessment based on geographical information systems.

Afghanistan continues to experience challenges affecting polio eradication. Mass polio vaccination campaigns, which aim to protect children under the age of 5, are a key eradication strategy. To date, the polio program in Afghanistan has only employed facility-based seroprevalence surveys, which can be subject to sampling bias. We describe the feasibility in implementing a cross-sectional household poliovirus seroprevalence survey based on geographical information systems (GIS) in three districts. Digital maps with randomly selected predetermined starting points were provided to teams, with a total target of 1,632 households. Teams were instructed to navigate to predetermined starting points and enrol the closest household within 60 m. To assess effectiveness of these methods, we calculated percentages for total households enrolled with valid geocoordinates collected within the designated boundary, and whether the Euclidean distance of households were within 60 m of a predetermined starting point. A normalized difference vegetation index (NDVI) image ratio was conducted to further investigate variability in team performances. The study enrolled a total of 78% of the target sample with 52% of all households within 60 m of a pre-selected point and 79% within the designated cluster boundary. Success varied considerably between the four target areas ranging from 42% enrolment of the target sample in one place to 90% enrolment of the target sample in another. Interviews with the field teams revealed that differences in security status and amount of non-residential land cover were key barriers to higher enrolment rates. Our findings indicate household poliovirus seroprevalence surveys using GIS-based sampling can be effectively implemented in polio endemic countries to capture representative samples. We also proposed ways to achieve higher success rates if these methods are to be used in the future, particularly in areas with concerns of insecurity or spatially dispersed residential units.

Social Vulnerability and Rurality Associated With Higher Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection-Induced Seroprevalence: A Nationwide Blood Donor Study-United States, July 2020-June 2021.

BACKGROUND: Most studies on health disparities during the coronavirus disease 2019 (COVID-19) pandemic focused on reported cases and deaths, which are influenced by testing availability and access to care. This study aimed to examine severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody seroprevalence in the United States and its associations with race/ethnicity, rurality, and social vulnerability over time. METHODS: This repeated cross-sectional study used data from blood donations in 50 states and Washington, DC, from July 2020 through June 2021. Donor zip codes were matched to counties and linked with Social Vulnerability Index (SVI) and urban-rural classification. SARS-CoV-2 antibody seroprevalences induced by infection and infection-vaccination combined were estimated. Association of infection-induced seropositivity with demographics, rurality, SVI, and its 4 themes were quantified using multivariate regression models. RESULTS: Weighted seroprevalence differed significantly by race/ethnicity and rurality, and increased with increasing social vulnerability. During the study period, infection-induced seroprevalence increased from 1.6% to 27.2% and 3.7% to 20.0% in rural and urban counties, respectively, while rural counties had lower combined infection- and vaccination-induced seroprevalence (80.0% vs 88.1%) in June 2021. Infection-induced seropositivity was associated with being Hispanic, non-Hispanic Black, and living in rural or more socially vulnerable counties, after adjusting for demographic and geographic covariates. CONCLUSIONS: The findings demonstrated increasing SARS-CoV-2 seroprevalence in the United States across all geographic, demographic, and social sectors. The study illustrated disparities by race-ethnicity, rurality, and social vulnerability. The findings identified areas for targeted vaccination strategies and can inform efforts to reduce inequities and prepare for future outbreaks.

Multifaceted Public Health Response to a COVID-19 Outbreak Among Meat-Processing Workers, Utah, March-June 2020.

OBJECTIVE: To identify potential strategies to mitigate COVID-19 transmission in a Utah meat-processing facility and surrounding community. DESIGN/SETTING: During March-June 2020, 502 workers at a Utah meat-processing facility (facility A) tested positive for SARS-CoV-2. Using merged data from the state disease surveillance system and facility A, we analyzed the relationship between SARS-CoV-2 positivity and worker demographics, work section, and geospatial data on worker residence. We analyzed worker survey responses to questions regarding COVID-19 knowledge, beliefs, and behaviors at work and home. PARTICIPANTS: (1) Facility A workers (n = 1373) with specimen collection dates and SARS-CoV-2 RT-PCR test results; (2) residential addresses of all persons (workers and nonworkers) with a SARS-CoV-2 diagnostic test (n = 1036), living within the 3 counties included in the health department catchment area; and (3) facility A workers (n = 64) who agreed to participate in the knowledge, attitudes, and practices survey. MAIN OUTCOME MEASURES: New cases over time, COVID-19 attack rates, worker characteristics by SARS-CoV-2 test results, geospatially clustered cases, space-time proximity of cases among workers and nonworkers; frequency of quantitative responses, crude prevalence ratios, and counts and frequency of coded responses to open-ended questions from the COVID-19 knowledge, attitudes, and practices survey. RESULTS: Statistically significant differences in race (P = .01), linguistic group (P < .001), and work section (P < .001) were found between workers with positive and negative SARS-CoV-2 test results. Geographically, only 6% of cases were within statistically significant spatiotemporal case clusters. Workers reported using handwashing (57%) and social distancing (21%) as mitigation strategies outside work but reported apprehension with taking COVID-19-associated sick leave. CONCLUSIONS: Mitigating COVID-19 outbreaks among workers in congregate settings requires a multifaceted public health response that is tailored to the workforce. IMPLICATIONS FOR POLICY AND PRACTICE: Tailored, multifaceted mitigation strategies are crucial for reducing COVID-19-associated health disparities among disproportionately affected populations.

Spatial analysis of genetic clusters and epidemiologic factors related to wild poliovirus type 1 persistence in Afghanistan and Pakistan.

Following the certification of the World Health Organization Region of Africa as free of serotype 1 wild poliovirus (WPV1) in 2020, Afghanistan and Pakistan represent the last remaining WPV1 reservoirs. As efforts continue in these countries to progress to eradication, there is an opportunity for a deeper understanding of the spatiotemporal characteristics and epidemiological risk factors associated with continual WPV1 circulation in the region. Using poliovirus surveillance data from 2017-2019, we used pairwise comparisons of VP1 nucleotide sequences to illustrate the spatiotemporal WPV1 dispersal to identify key sources and destinations of potentially infected, highly mobile populations. We then predicted the odds of WPV1 detection at the district level using a generalized linear model with structural indicators of health, security, environment, and population demographics. We identified evidence of widespread population mobility based on WPV1 dispersal within and between the countries, and evidence indicating five districts in Afghanistan (Arghandab, Batikot, Bermel, Muhamandara and Nawzad) and four districts in Pakistan (Charsada, Dera Ismail Khan, Killa Abdullah and Khyber) act as cross-border WPV1 circulation reservoirs. We found that the probability of detecting WPV1 in a district increases with each armed conflict event (OR = 1·024, +- 0·008), level of food insecurity (OR = 1·531, +-0·179), and mean degrees Celsius during the months of greatest precipitation (OR = 1·079, +- 0·019). Our results highlight the multidisciplinary complexities contributing to the continued transmission of WPV1 in Afghanistan and Pakistan. We discuss the implications of our results, stressing the value of coordination during this final chapter of the wild polio virus eradication initiative.

The role of heterogenous environmental conditions in shaping the spatiotemporal distribution of competing Aedes mosquitoes in Panama: implications for the landscape of arboviral disease transmission.

Monitoring the invasion process of the Asian tiger mosquito Aedes albopictus and its interaction with the contender Aedes aegypti, is critical to prevent and control the arthropod-borne viruses (i.e., Arboviruses) they transmit to humans. Generally, the superior ecological competitor Ae. albopictus displaces Ae. aegypti from most geographic areas, with the combining factors of biology and environment influencing the competitive outcome. Nonetheless, detailed studies asserting displacement come largely from sub-tropical areas, with relatively less effort being made in tropical environments, including no comprehensive research about Aedes biological interactions in Mesoamerica. Here, we examine contemporary and historical mosquito surveillance data to assess the role of shifting abiotic conditions in shaping the spatiotemporal distribution of competing Aedes species in the Republic of Panama. In accordance with prior studies, we show that Ae. albopictus has displaced Ae. aegypti under suboptimal wet tropical climate conditions and more vegetated environments within the southwestern Azuero Peninsula. Conversely, in the eastern Azuero Peninsula, Ae. aegypti persists with Ae. albopictus under optimal niche conditions in a dry and more seasonal tropical climate. While species displacement was stable over the course of two years, the presence of both species generally appears to fluctuate in tandem in areas of coexistence. Aedes albopictus was always more frequently found and abundant regardless of location and climatic season. The heterogenous environmental conditions of Panama shape the competitive outcome and micro-geographic distribution of Aedes mosquitoes, with potential consequences for the transmission dynamics of urban and sylvatic zoonotic diseases. SUPPLEMENTARY INFORMATION: The online version of this article (10.1007/s10530-021-02482-y).

Examining Wing Length-Abundance Relationships and Pyrethroid Resistance Mutations among Aedes albopictus in a Rapidly Growing Urban Area with Implications for Mosquito Surveillance and Control.

Aedes albopictus is a cosmopolitan mosquito species capable of transmitting arboviruses such as dengue, chikungunya, and Zika. To control this and similar species, public and private entities often rely on pyrethroid insecticides. In this study, we screened Ae. albopictus collected from June to August 2017 in Mecklenburg County, a rapidly growing urban area of North Carolina, for mutations conferring pyrethroid resistance and examined spatiotemporal patterns of specimen size as measured by wing length, hypothesizing that size variation could be closely linked to local abundance, making this easily measured trait a useful surveillance proxy. The genetic screening results indicated that pyrethroid resistance alleles are not present in this population, meaning that this population is likely to be susceptible to this commonly used insecticide class. We detected no significant associations between size and abundance-related factors, indicating that wing-size is not a useful proxy for abundance, and thus not useful to surveillance in this capacity. However, mosquitoes collected in June were significantly larger than July or August, which may result from meteorological conditions, suggesting that short-term weather cues may modulate morphological traits, which could then affect local fecundity and virus transmission dynamics, as previously reported.

Geographic Associations Between Social Factors and SARS-CoV-2 Testing Early in the COVID-19 Pandemic, February-June 2020, Massachusetts.

OBJECTIVES: Widespread SARS-CoV-2 testing is critical to identify infected people and implement public health action to interrupt transmission. With SARS-CoV-2 testing supplies and laboratory capacity now widely available in the United States, understanding the spatial heterogeneity of associations between social determinants and the use of SARS-CoV-2 testing is essential to improve testing availability in populations disproportionately affected by SARS-CoV-2. METHODS: We assessed positive and negative results of SARS-CoV-2 molecular tests conducted from February 1 through June 17, 2020, from the Massachusetts Virtual Epidemiologic Network, an integrated web-based surveillance and case management system in Massachusetts. Using geographically weighted regression and Moran's I spatial autocorrelation tests, we quantified the associations between SARS-CoV-2 testing rates and 11 metrics of the Social Vulnerability Index in all 351 towns in Massachusetts. RESULTS: Median SARS-CoV-2 testing rates decreased with increasing percentages of residents with limited English proficiency (median relative risk [interquartile range] = 0.96 [0.95-0.99]), residents aged ≥65 (0.97 [0.87-0.98]), residents without health insurance (0.96 [0.95-1.04], and people residing in crowded housing conditions (0.89 [0.80-0.94]). These associations differed spatially across Massachusetts, and localized models improved the explainable variation in SARS-CoV-2 testing rates by 8% to 12%. CONCLUSION: Indicators of social vulnerability are associated with variations in SARS-CoV-2 testing rates. Accounting for the spatial heterogeneity in these associations may improve the ability to explain and address the SARS-CoV-2 pandemic at substate levels.

Black men who have sex with men living in states with HIV criminalization laws report high stigma, 23 U.S. cities, 2017.

OBJECTIVES: To examine the association between HIV laws, perceived community stigma, and behaviors and to compare differences between and within Black and White men who have sex with men (MSM). DESIGN/METHODS: National HIV Behavioral Surveillance conducted interviews and HIV testing with MSM in 23 U.S. cities in 2017 using venue-based sampling methods. We used weighted cross-sectional data to compare MSM living in states with versus without HIV laws using Rao-Scott chi-square tests. We modeled the association between stigma and state HIV laws within racial groups to obtain adjusted prevalence ratios (aPR) and 95% confidence intervals (CIs). RESULTS: Among 7392 MSM, 56% lived in a state with HIV laws. In law states, Black MSM were more likely than White MSM to report their community would discriminate against persons with HIV (PWH) (59 versus 34%), not support the rights of PWH (20 versus 9%), not be friends with PWH (19 versus 10%), believe PWH 'got what they deserved' (27 versus 16%), and be intolerant of MSM (14 versus 5%). Adjusted for confounders, Black MSM in HIV law states were more likely to think their community would discriminate against PWH (aPR, 1.14; 95% CI, 1.02-1.29; P = 0.02) and be intolerant toward MSM (aPR, 2.02; 95% CI, 1.43-2.86; P < 0.001) than Black MSM in states without such laws. CONCLUSIONS: HIV laws were related to higher stigma, but only for Black MSM. Future research regarding HIV-related laws should account for racial/ethnic disparities. Modernizing laws can delegitimize stigma and promote focusing on effective HIV prevention strategies.

COVID-19 Vaccination Coverage Among Adults - United States, December 14, 2020-May 22, 2021.

The U.S. COVID-19 vaccination program launched on December 14, 2020. The Advisory Committee on Immunization Practices recommended prioritizing COVID-19 vaccination for specific groups of the U.S. population who were at highest risk for COVID-19 hospitalization and death, including adults aged ≥75 years*; implementation varied by state, and eligibility was gradually expanded to persons aged ≥65 years beginning in January 2021. By April 19, 2021, eligibility was expanded to all adults aged ≥18 years nationwide.† To assess patterns of COVID-19 vaccination coverage among U.S. adults, CDC analyzed data submitted on vaccinations administered during December 14, 2020-May 22, 2021, by age, sex, and community-level characteristics. By May 22, 2021, 57.0% of persons aged ≥18 years had received ≥1 COVID-19 vaccine dose; coverage was highest among persons aged ≥65 years (80.0%) and lowest among persons aged 18-29 years (38.3%). During the week beginning February 7, 2021, vaccination initiation among adults aged ≥65 years peaked at 8.2%, whereas weekly initiation among other age groups peaked later and at lower levels. During April 19-May 22, 2021, the period following expanded eligibility to all adults, weekly initiation remained <4.0% and decreased for all age groups, including persons aged 18-29 years (3.6% to 1.9%) and 30-49 years (3.5% to 1.7%); based on the current rate of weekly initiation (as of May 22), younger persons will not reach the same levels of coverage as older persons by the end of August. Across all age groups, coverage (≥1 dose) was lower among men compared with women, except among adults aged ≥65 years, and lower among persons living in counties that were less urban, had higher social vulnerabilities, or had higher percentages of social determinants of poor health. Continued efforts to improve vaccination confidence and alleviate barriers to vaccination initiation, especially among adults aged 18-49 years, could improve vaccination coverage.

Demographic and Social Factors Associated with COVID-19 Vaccination Initiation Among Adults Aged ≥65 Years - United States, December 14, 2020-April 10, 2021.

Compared with other age groups, older adults (defined here as persons aged ≥65 years) are at higher risk for COVID-19-associated morbidity and mortality and have therefore been prioritized for COVID-19 vaccination (1,2). Ensuring access to vaccines for older adults has been a focus of federal, state, and local response efforts, and CDC has been monitoring vaccination coverage to identify and address disparities among subpopulations of older adults (2). Vaccine administration data submitted to CDC were analyzed to determine the prevalence of COVID-19 vaccination initiation among adults aged ≥65 years by demographic characteristics and overall. Characteristics of counties with low vaccination initiation rates were quantified using indicators of social vulnerability data from the 2019 American Community Survey.* During December 14, 2020-April 10, 2021, nationwide, a total of 42,736,710 (79.1%) older adults had initiated vaccination. The initiation rate was higher among men than among women and varied by state. On average, counties with low vaccination initiation rates (<50% of older adults having received at least 1 vaccine dose), compared with those with high rates (≥75%), had higher percentages of older adults without a computer, living in poverty, without Internet access, and living alone. CDC, state, and local jurisdictions in partnerships with communities should continue to identify and implement strategies to improve access to COVID-19 vaccination for older adults, such as assistance with scheduling vaccination appointments and transportation to vaccination sites, or vaccination at home if needed for persons who are homebound.† Monitoring demographic and social factors affecting COVID-19 vaccine access for older adults and prioritizing efforts to ensure equitable access to COVID-19 vaccine are needed to ensure high coverage among this group.

County-Level COVID-19 Vaccination Coverage and Social Vulnerability - United States, December 14, 2020-March 1, 2021.

The U.S. COVID-19 vaccination program began in December 2020, and ensuring equitable COVID-19 vaccine access remains a national priority.* COVID-19 has disproportionately affected racial/ethnic minority groups and those who are economically and socially disadvantaged (1,2). Thus, achieving not just vaccine equality (i.e., similar allocation of vaccine supply proportional to its population across jurisdictions) but equity (i.e., preferential access and administra-tion to those who have been most affected by COVID-19 disease) is an important goal. The CDC social vulnerability index (SVI) uses 15 indicators grouped into four themes that comprise an overall SVI measure, resulting in 20 metrics, each of which has national and state-specific county rankings. The 20 metric-specific rankings were each divided into lowest to highest tertiles to categorize counties as low, moderate, or high social vulnerability counties. These tertiles were combined with vaccine administration data for 49,264,338 U.S. residents in 49 states and the District of Columbia (DC) who received at least one COVID-19 vaccine dose during December 14, 2020-March 1, 2021. Nationally, for the overall SVI measure, vaccination coverage was higher (15.8%) in low social vulnerability counties than in high social vulnerability counties (13.9%), with the largest coverage disparity in the socioeconomic status theme (2.5 percentage points higher coverage in low than in high vulnerability counties). Wide state variations in equity across SVI metrics were found. Whereas in the majority of states, vaccination coverage was higher in low vulnerability counties, some states had equitable coverage at the county level. CDC, state, and local jurisdictions should continue to monitor vaccination coverage by SVI metrics to focus public health interventions to achieve equitable coverage with COVID-19 vaccine.

Health Care Coverage and Preexposure Prophylaxis (PrEP) Use Among Men Who Have Sex With Men Living in 22 US Cities With vs Without Medicaid Expansion, 2017.

Objectives. To compare health care coverage and utilization between men who have sex with men (MSM) in Medicaid expansion versus nonexpansion states.Methods. We used cross-sectional weighted data from the National HIV Behavioral Surveillance system, which used venue-based methods to interview and test MSM in 22 US cities from June through December, 2017 (n = 8857). We compared MSM in Medicaid expansion versus nonexpansion states by using the Rao-Scott χ2 test stratified by HIV status. We used multivariable logistic regression to model the relationship between Medicaid expansion, coverage, and preexposure prophylaxis (PrEP) use.Results. MSM in expansion states were more likely to have insurance (87.9% vs 71.6%), have Medicaid (21.3% vs 3.8%), discuss PrEP with a provider (58.8% vs 44.3%), or use PrEP (31.1% vs 17.5%).Conclusions. Medicaid expansion is associated with higher coverage and care, including PrEP.Public Health Implications. States may consider expanding Medicaid to help end the HIV epidemic.

Assessing self-reported discrimination among men who have sex with men (MSM).

OBJECTIVES: To determine the prevalence of four forms of sexual identity discrimination among MSM in 23 US metropolitan statistical areas, examine racial/ethnic and socioeconomic disparities in each form of discrimination. METHODS: We examined interview data collected during 2017 for National HIV Behavioral Surveillance (n = 10 029 respondents) and used generalized linear models to assess the association between the prevalence of reported discrimination during the previous 12 months and selected sociodemographic groups. RESULTS: Overall, 34% of participants reported experiencing verbal discrimination; 16%, discrimination in a workplace, school, or a healthcare setting; and 8%, physical assault. MSM who had reported experiencing discrimination were most likely to be young, had achieved lower education, and had lower incomes. High prevalence of reported discrimination was associated with young age, lower education, lower household income, sexual identity disclosure, and lower perceived community tolerance of gay or bisexual persons. CONCLUSION: MSM discrimination affects different groups and occurs in multiple settings. Addressing discrimination should be an integral aspect of multifaceted efforts to improve MSM health.

Using Search Engine Data to Explore Interest in PrEP and HIV Testing in the United States.

We used Google search data from January 1, 2014 to January 1, 2019 to explore public awareness of pre-exposure prophylaxis (PrEP) and HIV testing in the United States. Using two search strings, one for PrEP and one for HIV testing, we compared search volume to state HIV prevalence and new HIV diagnoses. We also used Google News to identify news events related to short-term spikes in search volume. Controlling for poverty, education, and internet access, a one-unit increase in a state's HIV prevalence rate was associated with a 3% increase in PrEP search volume (aPR = 1.03 [1.034, 1.037], P < 0.0001) and HIV testing search volume (aPR = 1.03 [1.030, 1.032], P < 0.0001). Short-term search volume spikes also coincided with celebrity news and pharmaceutical company advertising. We demonstrate that search engine data can be a powerful tool for understanding HIV knowledge-seeking and can provide key insight to the events that drive public interest about HIV online.

RESUMEN: Usamos datos de búsqueda de Google desde el 1 de enero de 2014 hasta el 1 de enero de 2019 para explorar la conciencia pública sobre la profilaxis previa a la exposición (PrEP) y las pruebas del VIH en los Estados Unidos. Utilizando dos cadenas de búsqueda, una para PrEP y otra para pruebas de VIH, comparamos el volumen de búsqueda con la prevalencia del VIH estatal y los nuevos diagnósticos de VIH. También usamos Google News para identificar eventos de noticias relacionados con picos a corto plazo en el volumen de búsqueda. Al controlar la pobreza, la educación y el acceso a Internet, un aumento de una unidad en la tasa de prevalencia del VIH de un estado se asoció con un aumento del 3% en el volumen de búsqueda de PrEP (aPR = 1.03 [1.034, 1.037], P <0.0001) y la búsqueda de pruebas de VIH volumen (aPR = 1.03 [1.030, 1.032], P <0.0001). Los picos de volumen de búsqueda a corto plazo también coincidieron con noticias de celebridades y publicidad de compañías farmacéuticas. Demostramos que los datos de los motores de búsqueda pueden ser una herramienta poderosa para comprender la búsqueda de conocimientos sobre el VIH y pueden proporcionar información clave sobre los eventos que generan el interés público sobre el VIH en línea.

Distance matters: The association of proximity to syringe services programs with sharing of syringes and injecting equipment - 17 U.S. cities, 2015.

BACKGROUND: Syringe services programs (SSPs) have effectively limited the spread of HIV and hepatitis C (HCV) among people who inject drugs (PWID). Access to SSPs has been shown to reduce injection risk behaviors but the relationship between distance to an SSP and likelihood of sharing injection equipment is not well known. METHODS: We analyzed a sample of 8,392 PWID from 17 U.S. cities recruited through the National HIV Behavioral Surveillance (NHBS) system in 2015. Adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) were estimated from log-linked Poisson regression to explore associations between injecting equipment sharing in the past 12 months and distance to the nearest SSP. RESULTS: Regardless of SSP use, respondents who lived in zip codes further than the city-specific mean distance to nearest SSP were more likely to report sharing behavior. Among PWID who had not reported using an SSP in the previous 12 months, distributive sharing (aPR=1.13 95% CI=1.05, 1.21), receptive sharing (aPR=1.15, 95% CI=1.06, 1.24), and injection equipment sharing (aPR=1.08, 95% CI=1.03, 1.13) were more prevalent among residents who resided further than the average distance to the nearest SSP. CONCLUSIONS: Greater distance to an SSP was associated with increased sharing behaviors. Improved access to an SSP and subsequent decreases in sharing behaviors could reduce transmission of HIV and HCV among PWID. Accessibility should be taken into account when planning provision of SSPs.

Do socioeconomic factors drive Aedes mosquito vectors and their arboviral diseases? A systematic review of dengue, chikungunya, yellow fever, and Zika Virus.

As the threat of arboviral diseases continues to escalate worldwide, the question of, "What types of human communities are at the greatest risk of infection?" persists as a key gap in the existing knowledge of arboviral diseases transmission dynamics. Here, we comprehensively review the existing literature on the socioeconomic drivers of the most common Aedes mosquito-borne diseases and Aedes mosquito presence/abundance. We reviewed a total of 182 studies on dengue viruses (DENV), chikungunya virus (CHIKV), yellow fever virus (YFVV), Zika virus (ZIKV), and presence of Aedes mosquito vectors. In general, associations between socioeconomic conditions and both Aedes-borne diseases and Aedes mosquitoes are highly variable and often location-specific. Although 50% to 60% of studies found greater presence or prevalence of disease or vectors in areas with lower socioeconomic status, approximately half of the remaining studies found either positive or null associations. We discuss the possible causes of this lack of conclusiveness as well as the implications it holds for future research and prevention efforts.

Detecting space-time clusters of dengue fever in Panama after adjusting for vector surveillance data.

Long term surveillance of vectors and arboviruses is an integral aspect of disease prevention and control systems in countries affected by increasing risk. Yet, little effort has been made to adjust space-time risk estimation by integrating disease case counts with vector surveillance data, which may result in inaccurate risk projection when several vector species are present, and when little is known about their likely role in local transmission. Here, we integrate 13 years of dengue case surveillance and associated Aedes occurrence data across 462 localities in 63 districts to estimate the risk of infection in the Republic of Panama. Our exploratory space-time modelling approach detected the presence of five clusters, which varied by duration, relative risk, and spatial extent after incorporating vector species as covariates. The Ae. aegypti model contained the highest number of districts with more dengue cases than would be expected given baseline population levels, followed by the model accounting for both Ae. aegypti and Ae. albopictus. This implies that arbovirus case surveillance coupled with entomological surveillance can affect cluster detection and risk estimation, potentially improving efforts to understand outbreak dynamics at national scales.

High infestation of invasive Aedes mosquitoes in used tires along the local transport network of Panama.

BACKGROUND: The long-distance dispersal of the invasive disease vectors Aedes aegypti and Aedes albopictus has introduced arthropod-borne viruses into new geographical regions, causing a significant medical and economic burden. The used-tire industry is an effective means of Aedes dispersal, yet studies to determine Aedes occurrence and the factors influencing their distribution along local transport networks are lacking. To assess infestation along the primary transport network of Panama we documented all existing garages that trade used tires on the highway and surveyed a subset for Ae. aegypti and Ae. albopictus. We also assess the ability of a mass spectrometry approach to classify mosquito eggs by comparing our findings to those based on traditional larval surveillance. RESULTS: Both Aedes species had a high infestation rate in garages trading used tires along the highways, providing a conduit for rapid dispersal across Panama. However, generalized linear models revealed that the presence of Ae. aegypti is associated with an increase in road density by a log-odds of 0.44 (0.73 ± 0.16; P = 0.002), while the presence of Ae. albopictus is associated with a decrease in road density by a log-odds of 0.36 (0.09 ± 0.63; P = 0.008). Identification of mosquito eggs by mass spectrometry depicted similar occurrence patterns for both Aedes species as that obtained with traditional rearing methods. CONCLUSIONS: Garages trading used tires along highways should be targeted for the surveillance and control of Aedes-mosquitoes and the diseases they transmit. The identification of mosquito eggs using mass spectrometry allows for the rapid evaluation of Aedes presence, affording time and cost advantages over traditional vector surveillance; this is of importance for disease risk assessment.

Aedes Mosquito Infestation in Socioeconomically Contrasting Neighborhoods of Panama City.

The global expansion and proliferation of Aedes aegypti and Aedes albopictus represents a growing public health threat due to their capacity to transmit a variety of arboviruses to humans, including dengue, chikungunya, and Zika. Particularly important in urban regions, where these species have evolved to breed in man-made containers and feed nearly exclusively on human hosts, the threat of vector-borne disease has risen in recent decades due to the growth of cities, progression of climate change, and increase in globalization. While the dynamics of Aedes populations in urban settings have been well studied in relation to ecological features of the landscape, relatively less is known about the relationship between neighborhood socioeconomic status and Aedes infestation. Here, we compare infestation levels of both A. aegypti and A. albopictus in four socioeconomically contrasting neighborhoods of urban Panama City, Panama. Our results indicate that infestation levels for both Aedes species vary between neighborhoods of contrasting socioeconomic status, being higher in neighborhoods having lower percentage of residents with bachelor degrees and lower monthly household income. Additionally, we find that proximity between socioeconomically contrasting neighborhoods can predict infestation levels by species, with A. aegypti increasing and A. albopictus decreasing with proximity between neighborhoods. These findings hold key implications for the control and prevention of dengue, chikungunya, and Zika in Panama, a region with ongoing arbovirus outbreaks and high economic inequity.