Last data update: Apr 22, 2024. (Total: 46599 publications since 2009)
Records 1-30 (of 83 Records) |
Query Trace: Barrera R [original query] |
---|
Historical hot spots of Dengue and Zika viruses to guide targeted vector control in San Juan, Puerto Rico (2010-2022)
Barrera R . Am J Trop Med Hyg 2024 Dengue viruses (DENV) continue to cause large outbreaks in tropical countries, while chikungunya and Zika (ZIKV) viruses have added complexity to Aedes-borne disease prevention and control efforts. Because these viruses are transmitted by the same vectors in urban areas, it is useful to understand if sequential outbreaks caused by these viruses have commonalities, such as similar seasonal and spatial patterns, that would help anticipate and perhaps prevent future outbreaks. We explored and analyzed the heterogeneity of confirmed cases of DENV (2010-2014 and 2015-2022) and ZIKV (2016-2017) during outbreaks in the San Juan metropolitan area of Puerto Rico to explore their degree of overlap and prioritize areas for Aedes aegypti control. Deidentified, georeferenced case data were aggregated into grid cells (500 × 500 m) within a geographical information system of the study area and analyzed to calculate the degree of overlap between outbreaks. Spatial autocorrelations using local indicators of spatial associations were conducted to identify significant disease case hot spots and correlations between outbreaks. We found that 75% of cases during the three transmission periods were concentrated in 25% of the total number of grid cells covering the study area. We also found significant clustering of cases during each outbreak, enabling identification of consistent disease hot spots. Our results showed 85% spatial overlap between cases of ZIKV in 2015-2017 and DENV in 2010-2014 and 97% overlap between DENV cases in 2010-2014 and 2015-2022. These results reveal urban areas at greater risk of future arbovirus outbreaks that should be prioritized for vector control. |
El Niño Southern Oscillation (ENSO) effects on local weather, arboviral diseases, and dynamics of managed and unmanaged populations of Aedes aegypti (Diptera: Culicidae) in Puerto Rico
Barrera R , Acevedo V , Amador M , Marzan M , Adams LE , Paz-Bailey G . J Med Entomol 2023 60 (4) 796-807 We investigated the effects of interannual El Niño Southern Oscillation (ENSO) events on local weather, Aedes aegypti populations, and combined cases of dengue (DENV), chikungunya (CHIKV), and Zika (ZIKV) viruses in 2 communities with mass mosquito trapping and 2 communities without mosquito control in southern Puerto Rico (2013-2019). Gravid adult Ae. aegypti populations were monitored weekly using Autocidal Gravid Ovitraps (AGO traps). Managing Ae. aegypti populations was done using 3 AGO traps per home in most homes. There were drought conditions in 2014-2015 concurrent with the emergence of a strong El Niño (2014-2016), wetter conditions during La Niña (2016-2018), a major hurricane (2017), and a weaker El Niño (2018-2019). The main factor explaining differences in Ae. aegypti abundance across sites was mass trapping. Populations of Ae. aegypti reached maximum seasonal values during the wetter and warmer months of the year when arbovirus epidemics occurred. El Niño was significantly associated with severe droughts that did not impact the populations of Ae. aegypti. Arbovirus cases at the municipality level were positively correlated with lagged values (5-12 mo.) of the Oceanic El Niño Index (ONI), droughts, and abundance of Ae. aegypti. The onset of strong El Niño conditions in Puerto Rico may be useful as an early warning signal for arboviral epidemics in areas where the abundance of Ae. aegypti exceeds the mosquito density threshold value. |
Sexual exposures associated with mpox infection: California, November 2022 to June 2023
Snyder RE , Saadeh K , Tang EC , Johnson KA , Holland SN , Quint J , Burghardt NO , Chai SJ , Fernando R , Barrera KG , Hernandez C , McManus K , Lorenz K , Maycott J , McGinley J , Lewnard JA . J Infect Dis 2023 BACKGROUND: Exposures associated with mpox infection remain imperfectly understood. METHODS: We conducted a case-control study enrolling participants who received molecular tests for mpox/orthopoxvirus in California from November 2022 through June 2023. We collected data on behaviors during a 21-day risk period before symptom onset or testing among mpox cases and test-negative controls. RESULTS: Thirteen of 54 (24.1%) cases and 5/117 (4.3%) controls reported sexual exposure to individuals they identified as potential mpox cases ("index contacts"; odds ratio [OR] = 7.7 [95% confidence interval: 2.5-19.3]). Among these participants, 10/13 (76.9%) cases and 2/5 (40.0%) controls reported their index contacts were not experiencing symptoms visible to participants during sex (OR = 14.9 [3.6-101.8]). Only 3/54 cases (5.6%) reported exposure to symptomatic index contacts. Cases reported greater numbers of anal/vaginal sex partners than controls (adjusted OR = 2.2 [1.0-4.8] for 2-3 partners and 3.8 [1.7-8.8] for ≥4 partners). Male cases with penile lesions more commonly reported insertive anal/vaginal sex than those without penile lesions (adjusted OR = 9.3 [1.6-54.8]). Cases with anorectal lesions more commonly reported receptive anal sex than cases without anorectal lesions (adjusted OR = 14.4 [1.0-207.3]). CONCLUSIONS: Sexual exposure to contacts known or suspected to have experienced mpox was associated with increased risk of infection, often when index contacts lacked apparent symptoms. Exposure to greater numbers of sex partners, including those whom participants did not identify as index contacts, was associated with increased risk of infection in a site-specific manner. While participants' assessment of symptoms in partners may be imperfect, these findings suggest individuals without visibly prominent mpox symptoms transmit infection. |
COVID-19 testing of United States-bound agricultural workers in Mexico
Teleaga J , White ZA , Cervantes J , Assael R , Barrera G , Toney S , Marano N , Rodriguez Lainz A , Assael C , Ortega A , Chappelle CG , Bustamante N , Moser K , Posey DL . J Immigr Minor Health 2023 25 (6) 1295-1301 The COVID-19 pandemic presents global health, welfare, and economic concerns. The agricultural workforce has experienced adverse effects, placing the U.S. food supply at risk. Agricultural workers temporarily travel to the United States on H-2A visas to supplement the agricultural workforce. Approximately 300,000 agricultural workers enter the United States with H-2A visas each year; over 90.0% are from Mexico. During February-May 2021, a COVID-19 testing pilot was performed with Clínica Médica Internacional (CMI), a clinic that performs medical examinations for US-bound immigrants, to determine the SARS-CoV-2 infection status of H-2A agricultural workers in Mexico before entry to the US. The CerTest VIASURE Real Time PCR Detection Kit was used. Participants' demographic information, test results, and testing turnaround times were collected. Workers who tested positive for SARS-CoV-2 completed isolation before US entry. During the pilot, 1195 H-2A workers were tested; 15 (1.3%) tested positive. Average reporting time was 31 h after specimen collection. This pilot demonstrated there is interest from H-2A employers and agents in testing the H-2A community before US entry. Testing for SARS-CoV-2 can yield public health benefit, is feasible, and does not delay entry of temporary agricultural workers to the US. |
New tools for Aedes control: Mass trapping
Barrera R . Curr Opin Insect Sci 2022 52 100942 Aedes aegypti, the main vector of dengue, chikungunya, and Zika viruses uses artificial containers around homes to undergo immature development, making household-level detection and control extremely difficult in large urban areas. Mass trapping is an emerging methodology to control container-Aedes species such as Aedes aegypti and Aedes albopictus because effective traps for adult stages of these mosquitoes were developed recently. There are three main approaches to mass-trapping these mosquitoes: 1) Pull (attract/kill), 2) push (repel) - pull (attract/kill), and 3) pull (attract/contaminate/infect) - push (fly away). Effective mass-trapping depends on trap quality (capture efficiency, sturdiness, frequency of servicing), trap density and areal coverage, community involvement, and safety. Recent studies showed that Ae. aegypti populations can be sustainably controlled by mass trapping, although more area-wide studies showing effectiveness at preventing disease are needed for all trapping systems. Cost-effectiveness studies are needed for all emerging Aedes control approaches. |
County-level associations between pregnancy-related mortality ratios and contextual sociospatial indicators
Barrera CM , Kramer MR , Merkt PT , Petersen EE , Brantley MD , Eckhaus L , Beauregard JL , Goodman DA . Obstet Gynecol 2022 139 (5) 855-865 OBJECTIVE: To characterize county-level differences in pregnancy-related mortality as a function of sociospatial indicators. METHODS: We conducted a cross-sectional multilevel analysis of all pregnancy-related deaths and all live births with available ZIP code or county data in the Pregnancy Mortality Surveillance System during 2011-2016 for non-Hispanic Black, Hispanic (all races), and non-Hispanic White women aged 15-44 years. The exposures included 31 conceptually-grounded, county-specific sociospatial indicators that were collected from publicly available data sources and categorized into domains of demographic; general, reproductive, and behavioral health; social capital and support; and socioeconomic contexts. We calculated the absolute difference of county-level pregnancy-related mortality ratios (deaths per 100,000 live births) per 1-unit increase in the median absolute difference between women living in counties with higher compared with lower levels of each sociospatial indicator overall and stratified by race and ethnicity. RESULTS: Pregnancy-related mortality varied across counties and by race and ethnicity. Many sociospatial indicators were associated with county-specific pregnancy-related mortality ratios independent of maternal age, population size, and Census region. Across domains, the most harmful indicators were percentage of low-birth-weight births (absolute ratio difference [RD] 6.44; 95% CI 5.36-7.51), percentage of unemployed adults (RD 4.98; 95% CI 3.91-6.05), and food insecurity (RD 4.92; 95% CI 4.14-5.70). The most protective indicators were higher median household income (RD -2.76; 95% CI -3.28 to -2.24), percentage of college-educated adults (RD -2.28; 95% CI -2.81 to -1.75), and percentage of owner-occupied households (RD -1.66; 95% CI -2.29 to -1.03). The magnitude of these associations varied by race and ethnicity. CONCLUSION: This analysis identified sociospatial indicators of pregnancy-related mortality and showed an association between pregnancy-related deaths and place of residence overall and stratified by race and ethnicity. Understanding county-level context associated with pregnancy-related mortality may be an important step towards building public health evidence to inform action to reduce pregnancy-related mortality at local levels. |
Surveillance and control of culex quinquefasciatus using autocidal gravid ovitraps
Barrera R , Acevedo V , Amador M . J Am Mosq Control Assoc 2022 38 (1) 19-23 We monitored trap captures of Culex quinquefasciatus using an interrupted time-series study to determine if autocidal gravid ovitraps (AGO traps) were useful to control the population of this mosquito species in a community in southern Puerto Rico. Data for this report came from a previous study in which we used mass trapping to control Aedes aegypti, resulting in a significant 79% reduction in numbers of this species. The AGO traps used to monitor and control Ae. aegypti also captured numerous Cx. quinquefasciatus. Culex quinquefasciatus was monitored in surveillance AGO traps from October 2011 to February 2013, followed by a mosquito control intervention from February 2013 to June 2014. Optimal captures of this mosquito occurred on the 2nd wk after the traps were set or serviced, which happened every 8 wk. Changes in collection numbers of Cx. quinquefasciatus were positively correlated with rainfall and showed oscillations every 8 wk, as revealed by sample autocorrelation analyses. Culex quinquefasciatus was attracted to and captured by AGO traps, so mass trapping caused a significant but moderate reduction of the local population (31.2%) in comparison with previous results for Ae. aegypti, possibly resulting from female mosquitoes flying in from outside of the study area and decreased attraction to the traps past the 2nd wk of trap servicing. Because Ae. aegypti and Cx. quinquefasciatus are frequently established in urban areas, mass trapping to control the former has some impact on Cx. quinquefasciatus. Control of the latter could be improved by locating and treating its aquatic habitats within and around the community. |
Cemeteries as sources of Aedes aegypti and other mosquito species in southeastern Puerto Rico
Otero LM , Medina-Martinez G , Seplveda M , Acevedo V , Toro M , Barrera R . Trop Med Int Health 2022 27 (3) 300-309 OBJECTIVE: To investigate the presence and abundance of mosquito species in containers found in different types of cemeteries in Puerto Rico to assess their importance and make control recommendations. METHODS: We conducted surveys of containers with water in 16 cemeteries in southeastern Puerto Rico to: detect the presence of larvae and pupae of Aedes aegypti and other mosquitoes; identify the most common and productive containers and study their variation in relation to the type of cemetery. RESULTS: The most common containers with water were flowerpots, followed in abundance by a variety of discarded containers and open tombs. We found a positive relationship between density of containers with water and rainfall. There was a rich community of mosquito species developing in containers of the inspected cemeteries: nine mosquito species belonging to four genera with Ae. aegypti and Ae. mediovittatus being the most frequent and abundant. We sampled 13 cement type cemeteries, 2 mixed, and only 1 lawn cemetery, consequently we could not draw any conclusion regarding container productivity and cemetery type. CONCLUSIONS: Surveyed cemeteries were important sources of Ae. aegypti and other mosquitoes in flowerpots, discarded containers, and open tombs. We recommend conducting further studies to establish how frequently inspections should occur; and mosquito control by emptying aquatic habitats and larviciding to reduce mosquito productivity and protect workers and visitors from mosquito bites and possible transmission of arboviruses. |
Assessment of community support for Wolbachia-mediated population suppression as a control method for Aedes aegypti mosquitoes in a community cohort in Puerto Rico
Sánchez-González L , Adams LE , Saavedra R , Little EM , Medina NA , Major CG , Bruck M , Miranda J , Rosado-Santiago C , Ryff K , Ortiz M , Brown G , Barrera R , Pérez-Guerra CL , Rivera-Amill V , Paz-Bailey G . PLoS Negl Trop Dis 2021 15 (12) e0009966 Arboviral diseases transmitted by Aedes species mosquitoes pose an increasing public health challenge in tropical regions. Wolbachia-mediated population suppression (Wolbachia suppression) is a vector control method used to reduce Aedes mosquito populations by introducing male mosquitoes infected with Wolbachia, a naturally occurring endosymbiotic bacterium. When Wolbachia-infected male mosquitoes mate with female wild mosquitoes, the resulting eggs will not hatch. Public support is vital to the successful implementation and sustainability of vector control interventions. Communities Organized to Prevent Arboviruses (COPA) is a cohort study to determine the incidence of arboviral disease in Ponce, Puerto Rico and evaluate vector control methods. Focus groups were conducted with residents of COPA communities to gather their opinion on vector control methods; during 2018-2019, adult COPA participants were interviewed regarding their views on Wolbachia suppression; and a follow-up questionnaire was conducted among a subset of participants and non-participants residing in COPA communities. We analyzed factors associated with support for this method. Among 1,528 participants in the baseline survey, median age was 37 years and 63% were female. A total of 1,032 (68%) respondents supported Wolbachia suppression. Respondents with an income of $40,000 or more were 1.34 times as likely [95% CI: 1.03, 1.37] to support Wolbachia suppression than those who earned less than $40,000 annually. Respondents who reported repellant use were 1.19 times as likely to support Wolbachia suppression [95% CI: 1.03, 1.37]. A follow-up survey in 2020 showed that most COPA participants (86%) and non-participants living in COPA communities (84%) supported Wolbachia suppression during and after an educational campaign. The most frequent questions regarding this method were related to its impact on human and animal health, and the environment. Continuous community engagement and education efforts before and during the implementation of novel vector control interventions are necessary to increase and maintain community support. |
Multi-Year Mass-Trapping With Autocidal Gravid Ovitraps has Limited Influence on Insecticide Susceptibility in Aedes aegypti (Diptera: Culicidae) From Puerto Rico.
Hemme RR , Smith EA , Felix G , White BJ , Diaz-Garcia MI , Rodriguez D , Ruiz-Valcarcel J , Acevedo V , Amador M , Barrera R . J Med Entomol 2021 59 (1) 314-319 Mass-trapping has been used to control outbreaks of Aedes aegypti (Linnaeus) (Diptera: Culicidae) in Puerto Rico since 2011. We investigated the effect of multi-year, insecticide-free mass trapping had on the insecticide susceptibility profile of Ae. aegypti. Eggs collected in southern Puerto Rico were used to generate F1 populations that were tested for susceptibility to permethrin, sumethrin, bifenthrin, deltamethrin, and malathion according to CDC bottle bioassays protocols. All populations of Ae. aegypti were resistant to the synthetic pyrethroids and mosquitoes from two locations were partially resistant to malathion. Population genetic analysis, using a double digest restriction sites associated DNA sequencing (ddRADseq) approach, indicated a large amount of migration between study sites effectively homogenizing the mosquito populations. Mass-trapping using noninsecticidal autocidal gravid ovitraps did not restore susceptibility to five active ingredients that are found in commercial insecticides. Migration between communities was high and would have brought outside alleles, including resistant alleles to the treatment communities. Further investigation suggests that household use of commercially available insecticide products may continue to select for resistance in absence of public health space spraying of insecticides. |
Improving the Safety and Acceptability of Autocidal Gravid Ovitraps (AGO Traps)
Acevedo V , Amador M , Barrera R . J Am Mosq Control Assoc 2021 37 (2) 61-67 Gravid traps that collect eggs or adult mosquitoes use color, size, or volume as well as water or plant infusions as attractants. Biorational larvicides have been used to prevent these devices from producing adult mosquitoes within the traps. Results from field assays on the use of several biorational larvicides for various mosquito species have provided mixed results in terms of increased, neutral, or reduced attraction. We investigated the use of Bacillus thuringiensis var. israelensis, spinosad, and novaluron in field assays in Puerto Rico to evaluate the behavioral response of Aedes aegypti and Culex spp. to autocidal gravid ovitraps (AGO traps). The purpose of the study was to increase the safety of these traps by preventing accidental release of adult mosquitoes when traps are opened or damaged. We also investigated whether trap color (blue, green, terracotta) that may be more amenable for use by residents in their properties induced a similar attraction response to the original black trap color. We found that the use of biorational larvicides did not significantly change the behavioral attraction of these mosquito species to AGO traps. For Ae. aegypti, green traps yielded the lowest captures while black, terracotta, and blue produced similar higher yields. Culex spp. in black traps showed significantly higher captures compared with other colors. These results suggest that black, terracotta, or blue AGO traps can be used for the surveillance and control of Ae. aegypti. |
Lower socioeconomic status neighborhoods in Puerto Rico have more diverse mosquito communities and higher Aedes aegypti abundance
Scavo NA , Barrera R , Reyes-Torres LJ , Yee DA . J Urban Ecol 2021 7 (1) Mosquito community dynamics in urban areas are influenced by an array of both social and ecological factors. Human socioeconomic factors (SEF) can be related to mosquito abundance and diversity as urban mosquito development sites are modified by varying human activity, e.g., level of abandoned structures or amount of accumulated trash. The goal of this study was to investigate the relationships among mosquito diversity, populations of Aedes aegypti, and SEF in a tropical urban setting. Mosquitoes were collected using BG Sentinel 2 traps and CDC light traps during three periods between late 2018 and early 2019 in San Juan, Puerto Rico, and were identified to species. SEFs (i.e. median household income, population density, college-level educational attainment, unemployment, health insurance coverage, percentage of households below the poverty line, amount of trash and level of abandoned homes) were measured using foot surveys and U.S. Census data. We found 19 species with the two most abundant species being Culex quinquefasciatus (n = 10 641, 87.6%) and Ae. aegypti (n = 1558, 12.8%). We found a positive association between Ae. aegypti abundance and mosquito diversity, which were both negatively related to SES and ecological factors. Specifically, lower socioeconomic status neighborhoods had both more Ae. aegypti and more diverse communities, due to more favorable development habitat, indicating that control efforts should be focused in these areas. © 2021 The Author(s). |
Microbial Diversity of Adult Aedes aegypti and Water Collected from Different Mosquito Aquatic Habitats in Puerto Rico
Caragata EP , Otero LM , Tikhe CV , Barrera R , Dimopoulos G . Microb Ecol 2021 83 (1) 182-201 Mosquitoes, the major vectors of viruses like dengue, are naturally host to diverse microorganisms, which play an important role in their development, fecundity, immunity, and vector competence. The composition of their microbiota is strongly influenced by the environment, particularly their aquatic larval habitat. In this study, we used 2×300 bp 16s Illumina sequencing to compare the microbial profiles of emerging adult Aedes aegypti mosquitoes and the water collected from common types of aquatic habitat containers in Puerto Rico, which has endemic dengue transmission. We sequenced 141 mosquito and 46 water samples collected from plastic containers, septic tanks, discarded tires, underground trash cans, tree holes, or water meters. We identified 9 bacterial genera that were highly prevalent in the mosquito microbiome, and 77 for the microbiome of the aquatic habitat. The most abundant mosquito-associated bacterial OTUs were from the families Burkholderiaceae, Pseudomonadaceae, Comamonadaceae, and Xanthomonadaceae. Microbial profiles varied greatly between mosquitoes, and there were few major differences explained by container type; however, the microbiome of mosquitoes from plastic containers was more diverse and contained more unique taxa than the other groups. Container water was significantly more diverse than mosquitoes, and our data suggest that mosquitoes filter out many bacteria, with Alphaproteobacteria in particular being far more abundant in water. These findings provide novel insight into the microbiome of mosquitoes in the region and provide a platform to improve our understanding of the fundamental mosquito-microbe interactions. |
Urban-Rural Differences in Pregnancy-Related Deaths, United States, 2011-2016
Merkt PT , Kramer MR , Goodman DA , Brantley MD , Barrera CM , Eckhaus L , Petersen EE . Am J Obstet Gynecol 2021 225 (2) 183 e1-183 e16 BACKGROUND: The U.S. pregnancy-related mortality ratio has not improved over the past decade and includes striking disparities by race/ethnicity and by state. Understanding differences in pregnancy-related mortality across and within urban and rural areas can guide the development of interventions for preventing future pregnancy-related deaths. OBJECTIVE: We sought to compare pregnancy-related mortality across and within urban and rural counties by race/ethnicity and age. STUDY DESIGN: We conducted a descriptive analysis of 3,747 pregnancy-related deaths during 2011-2016 (the most recent available) with available ZIP code or county data in the Pregnancy Mortality Surveillance System, among Hispanic and non-Hispanic White, Black, American Indian/Alaska Native, and Asian/Pacific Islander women ages 15-44 years. We aggregated data by U.S. county and grouped counties per the National Center for Health Statistics Urban-Rural Classification Scheme for Counties. We used R statistical software, epitools, to calculate the pregnancy-related mortality ratio (number of pregnancy-related deaths per 100,000 live births) for each urban-rural grouping, obtain 95% confidence intervals, and perform exact tests of ratio comparisons using the Poisson distribution. RESULTS: Of the total 3,747 pregnancy-related deaths analyzed, 52% occurred in large metro counties and 7% occurred in noncore (rural) counties. Large metro counties had the lowest pregnancy-related mortality ratio (14.8, 95% CI: 14.2-15.5) while noncore counties had the highest (24.1, 95% CI: 21.4-27.1), including for most race/ethnicity and age groups. Pregnancy-related mortality ratio age disparities increased with rurality. Women ages 25-34 years and ages 35-44 years living in noncore counties had pregnancy-related mortality ratios 1.5 and 3 times higher, respectively, than women of the same age groups in large metro counties. Within each urban-rural category, pregnancy-related mortality ratios were higher among non-Hispanic Black women compared to non-Hispanic White women. Non-Hispanic American Indian/Alaska Native pregnancy-related mortality ratios in small metro, micropolitan, and noncore counties were 2-3 times that of non-Hispanic White women in the same areas. CONCLUSION: Although more than half of pregnancy-related deaths occurred in large metro counties, the pregnancy-related mortality ratio rose with increasing rurality. Disparities existed among urban-rural categories, including by age group and by race/ethnicity. Geographic location is an important context for initiatives to prevent future deaths and eliminate disparities. Further research is needed to better understand reasons for the observed urban-rural differences and to guide a multifactorial response to reduce pregnancy-related deaths. |
Factors modulating captures of gravid aedes aegypti females
Barrera R , Amador M , Ruiz-Valcarcel J , Acevedo V . J Am Mosq Control Assoc 2020 36 (2) 66-73 To improve detection and assessment of Aedes aegypti abundance, we investigated whether microhabitat factors of the location of autocidal gravid ovitraps (AGO traps) influenced captures of gravid females in 2 locations in southern Puerto Rico. One location had been under vector control for several years using mass AGO trapping (intervention site), where Ae. aegypti abundance was several times lower than in the other study site without mosquito control (nonintervention site). We observed 10 environmental factors describing trap microhabitat location, and monitored water volume and minimum, maximum, and average temperature in AGO traps. Air temperature, relative humidity, and rainfall were recorded at each site. We conducted a hot-spot analysis of AGO traps to understand whether trap captures were influenced by the local abundance of mosquitoes rather than or in addition to trap microhabitat factors. AGO traps were classified using a 2-step cluster analysis based on attributes of trap microhabitats, water temperature, and water volume. Captures of female Ae. aegypti in each cluster per site were compared between resulting clusters to determine whether trap microhabitat factors defining the clusters were associated with trap captures. Trap captures in both study sites were mostly correlated with captures in nearby traps regardless of trap microhabitat factors, possibly reflecting the influence of the spatial aggregation of mosquitoes coming from nearby aquatic habitats or the concentration of dispersing adults. These results indicated that AGO traps can be located at places that can be easily reached during periodic inspections, such as in front of houses, without much regard to local microhabitat conditions. |
Role of abandoned and vacant houses on Aedes aegypti productivity
Barrera R , Acevedo V , Amador M . Am J Trop Med Hyg 2020 104 (1) 145-150 The control of container Aedes species by house inspections usually achieves insufficient coverage and impact because a percentage of residents are absent and some residents refuse inspections and treatments. In addition, another fraction of the buildings may be uninhabited, such as those for rent or sale, or abandoned. Although the productivity of Aedes aegypti has been investigated in abandoned lots, less is known about the importance of uninhabited buildings. We investigated Ae. aegypti pupal productivity in inhabited, vacant, and abandoned houses and its interaction with socioeconomic levels (SELs). We found pupae in containers of 386 houses (66 abandoned, 62 vacant, and 258 inhabited) in 19 neighborhoods in southern Puerto Rico from May to August 2017. Using a generalized linear model, we found a significant interaction between the status of the house (abandoned, vacant, and inhabited) and SELs (low, medium) on Ae. aegypti pupal abundance. More pupae were found in abandoned and inhabited houses of low SELs. The lowest productivity was found in vacant houses, regardless of the SEL. Most containers producing Ae. aegypti in low-SEL houses were discarded on backyards, whereas in medium SELs, most productivity came from containers in use. Septic tanks producing Ae. aegypti were found only in houses of low SELs, where most emerging mosquitoes came from inhabited houses. We did not find any pupae of Ae. aegypti on roofs. These results indicate that proper yard management could significantly reduce the production of Ae. aegypti and the risk of dengue infections in low-SEL neighborhoods. |
Continuation of mosquito surveillance and control during public health emergencies and natural disasters
Connelly CR , Gerding JA , Jennings SM , Ruiz A , Barrera R , Partridge S , Ben Beard C . MMWR Morb Mortal Wkly Rep 2020 69 (28) 938-940 Mosquitoborne disease outbreaks occur every year in the United States from one or more of the arboviral diseases dengue, West Nile, LaCrosse, Eastern equine encephalitis, and Zika (1). Public opinion communicated through traditional and social media and the Internet, competing public health and resource priorities, and local conditions can impede the ability of vector control organizations to prevent and respond to outbreaks of mosquitoborne disease. The Environmental Protection Agency (EPA) and CDC performed a coordinated review of the concerns and challenges associated with continuation of mosquito surveillance and control during public health emergencies and disasters. This report highlights the first joint recommendation from EPA and CDC. Mosquito surveillance and control should be maintained by state and local mosquito control organizations to the extent that local conditions and resources will allow during public health emergencies and natural disasters. Integrated pest management (IPM) is the best approach for mosquito control (2). IPM uses a combination of methods, including both physical and chemical means of control (3). For chemical means of control, CDC and EPA recommend the use of larvicides and adulticides following the EPA label. It is imperative that public health recommendations be followed to ensure the safety of the pesticide applicator and the public. |
Dispersal of female and male Aedes aegypti from discarded container habitats using a stable isotope mark-capture study design in South Texas
Juarez JG , Garcia-Luna S , Chaves LF , Carbajal E , Valdez E , Avila C , Tang W , Martin E , Barrera R , Hemme RR , Mutebi JP , Vuong N , Roark EB , Maupin CR , Badillo-Vargas IE , Hamer GL . Sci Rep 2020 10 (1) 6803 Aedes aegypti is the main vector of arboviral diseases such as dengue, chikungunya and Zika. A key feature for disease transmission modeling and vector control planning is adult mosquito dispersal. We studied Ae aegypti adult dispersal by conducting a mark-capture study of naturally occurring Ae. aegypti from discarded containers found along a canal that divided two residential communities in Donna, Texas, USA. Stable isotopes were used to enrich containers with either (13)C or (15)N. Adult mosquitoes were collected outdoors in the yards of households throughout the communities with BG Sentinel 2 traps during a 12-week period. Marked mosquito pools with stable isotopes were used to estimate the mean distance travelled using three different approaches (Net, Strip or Circular) and the probability of detecting an isotopically marked adult at different distances from the larval habitat of origin. We consistently observed, using the three approaches that male (Net: 220 m, Strip: 255 m, Circular: 250 m) Ae. aegypti dispersed further in comparison to gravid (Net: 135 m, Strip: 176 m, Circular: 189 m) and unfed females (Net: 192 m, Strip: 213 m, Circular: 198 m). We also observed that marked male capture probability slightly increased with distance, while, for both unfed and gravid females, such probability decreased with distance. Using a unique study design documenting adult dispersal from natural larval habitat, our results suggest that Ae. aegypti adults disperse longer distances than previously reported. These results may help guide local vector control authorities in their fight against Ae. aegypti and the diseases it transmits, suggesting coverage of 200 m for the use of insecticides and innovative vector control tools. |
A 70% reduction in mosquito populations does not require removal of 70% of mosquitoes
Lega J , Brown HE , Barrera R . J Med Entomol 2020 57 (5) 1668-1670 We added a vector control component to our existing abundance model to simulate intensive vector control in Puerto Rico. Removing 20-30% of gravid females in the model matches observed 60-80% reductions. The model's capacity to reproduce vector control increases its utility for planning and evaluation strategies. |
Entomological investigation detects dengue virus type 1 in Aedes (Stegomyia) albopictus (Skuse) during the 2015-16 outbreak in Hawaii
Hasty JM , Felix GE , Amador M , Barrera R , Santiago GS , Nakasone L , Park SY , Okoji S , Honda E , Asuncion B , Save M , Munoz-Jordan JL , Martinez-Conde S , Medina FA , Waterman SH , Petersen LR , Johnston DI , Hemme RR . Am J Trop Med Hyg 2020 102 (4) 869-875 A dengue outbreak occurred on Hawaii Island between September 2015 and March 2016. Entomological investigations were undertaken between December 2015 and February 2016 to determine which Aedes mosquito species were responsible for the outbreak. A total of 3,259 mosquitoes were collected using a combination of CDC autocidal gravid ovitraps, Biogents BG-Sentinel traps, and hand-nets; immature mosquitoes were collected during environmental surveys. The composition of species was Aedes albopictus (58%), Aedes aegypti (25%), Wyeomyia mitchelli (7%), Aedes vexans (5%), Culex quinquefasciatus (4%), and Aedes japonicus (1%). Adult mosquitoes were analyzed by real-time reverse transcription polymerase chain reaction (PCR) for the presence of dengue virus (DENV) RNA. Of the 185 pools of female mosquitoes tested, 15 containing Ae. albopictus were positive for the presence of DENV type 1 RNA. No virus was detected in pools of the remaining species. Phylogenetic analysis showed the virus strain belonged to genotype I and was closely related to strains that were circulating in the Pacific between 2008 and 2014. This is the first report of detection of DENV in Ae. albopictus from Hawaii. |
Comparing vector and human surveillance strategies to detect arbovirus transmission: A simulation study for Zika virus detection in Puerto Rico
Madewell ZJ , Hemme RR , Adams L , Barrera R , Waterman SH , Johansson MA . PLoS Negl Trop Dis 2019 13 (12) e0007988 BACKGROUND: Detecting and monitoring the transmission of arboviruses such as Zika virus (ZIKV), dengue virus, and chikungunya virus is critical for prevention and control activities. Previous work has compared the ability of different human-focused surveillance strategies to detect ZIKV transmission in U.S. counties where no known transmission had occurred, but whether virological surveillance in mosquitoes could represent an effective surveillance system is unclear. OBJECTIVES: We leveraged a unique set of data from human and virological surveillance in Ae. aegypti during the 2016 ZIKV epidemic in Caguas, Puerto Rico, to compare alternative strategies for detecting and monitoring ZIKV activity. METHODS: We developed a simulation model for mosquito and human surveillance strategies and simulated different transmission scenarios with varying infection rates and mosquito trap densities. We then calculated the expected weekly number of detected infections, the probability of detecting transmission, and the number of tests needed and compared the simulations with observed data from Caguas. RESULTS: In simulated high transmission scenarios (1 infection per 1,000 people per week), the models demonstrated that both approaches had estimated probabilities of detection of greater than 78%. In simulated low incidence scenarios, vector surveillance had higher sensitivity than human surveillance and sensitivity increased with more traps, more trapping effort, and testing. In contrast, the actual data from Caguas indicated that human virological surveillance was more sensitive than vector virological surveillance during periods of both high and low transmission. CONCLUSION: In scenarios where human surveillance is not possible or when transmission intensity is very low, virological surveillance in Ae. aegypti may be able to detect and monitor ZIKV epidemic activity. However, surveillance for humans seeking care for Zika-like symptoms likely provides an equivalent or more sensitive indicator of transmission intensity in most circumstances. |
Rapid screening of Aedes aegypti mosquitoes for susceptibility to insecticides as part of Zika emergency response, Puerto Rico
Hemme RR , Vizcaino L , Harris AF , Felix G , Kavanaugh M , Kenney JL , Nazario NM , Godsey MS , Barrera R , Miranda J , Lenhart A . Emerg Infect Dis 2019 25 (10) 1959-1961 In response to the 2016 Zika outbreak, Aedes aegypti mosquitoes from 38 locations across Puerto Rico were screened using Centers for Disease Control and Prevention bottle bioassays for sensitivity to insecticides used for mosquito control. All populations were resistant to pyrethroids. Naled, an organophosphate, was the most effective insecticide, killing all mosquitoes tested. |
Autocidal gravid ovitraps protect humans from chikungunya virus infection by reducing Aedes aegypti mosquito populations
Sharp TM , Lorenzi O , Torres-Velasquez B , Acevedo V , Perez-Padilla J , Rivera A , Munoz-Jordan J , Margolis HS , Waterman SH , Biggerstaff BJ , Paz-Bailey G , Barrera R . PLoS Negl Trop Dis 2019 13 (7) e0007538 BACKGROUND: Public health responses to outbreaks of dengue, chikungunya, and Zika virus have been stymied by the inability to control the primary vector, Aedes aegypti mosquitos. Consequently, the need for novel approaches to Aedes vector control is urgent. Placement of three autocidal gravid ovitraps (AGO traps) in ~85% of homes in a community was previously shown to sustainably reduce the density of female Ae. aegypti by >80%. Following the introduction of chikungunya virus (CHIKV) to Puerto Rico, we conducted a seroprevalence survey to estimate the prevalence of CHIKV infection in communities with and without AGO traps and evaluate their effect on reducing CHIKV transmission. METHODS AND FINDINGS: Multivariate models that calculated adjusted prevalence ratios (aPR) showed that among 175 and 152 residents of communities with and without AGO traps, respectively, an estimated 26.1% and 43.8% had been infected with CHIKV (aPR = 0.50, 95% CI: 0.37-0.91). After stratification by time spent in their community, protection from CHIKV infection was strongest among residents who reported spending many or all weekly daytime hours in their community:10.3% seropositive in communities with AGO traps vs. 48.7% in communities without (PR = 0.21, 95% CI: 0.11-0.41). The age-adjusted rate of fever with arthralgia attributable to CHIKV infection was 58% (95% CI: 46-66%). The monthly number of CHIKV-infected mosquitos and symptomatic residents were diminished in communities with AGO traps compared to those without. CONCLUSIONS: These findings indicate that AGO traps are an effective tool that protects humans from infection with a virus transmitted by Ae. aegypti mosquitos. Future studies should evaluate their protective effectiveness in large, urban communities. |
Emergency declarations for public health issues: Expanding our definition of emergency
Sunshine G , Barrera N , Corcoran AJ , Penn M . J Law Med Ethics 2019 47 95-99 Emergency declarations are a vital legal authority that can activate funds, personnel, and material and change the legal landscape to aid in the response to a public health threat. Traditionally, declarations have been used against immediate and unforeseen threats such as hurricanes, tornadoes, wildfires, and pandemic influenza. Recently, however, states have used emergency declarations to address public health issues that have existed in communities for months and years and have risk factors such as poverty and substance misuse. Leaders in these states have chosen to use emergency powers that are normally reserved for sudden catastrophes to address these enduring public health issues. This article will explore emergency declarations as a legal mechanism for response; describe recent declarations to address hepatitis A and the opioid overdose epidemic; and seek to answer the question of whether it is appropriate to use emergency powers to address public health issues that are not traditionally the basis for an emergency declaration. |
Number of eating occasions and source of foods and drinks among young children in the United States: NHANES, 2009-2014
Barrera CM , Moore LV , Perrine CG , Hamner HC . Nutrients 2019 11 (4) An understanding of the source of children's foods and drinks is needed to identify the best intervention points for programs and policies aimed at improving children's diets. The mean number and type of eating occasions and the relative proportions of foods and drinks consumed from different sources were calculated among children aged 1-4 years (n = 2640) using data from the 2009-2014 National Health and Nutrition Examination Surveys. Children consumed 2.9 meals and 2.4 snacks each day. Among children who received anything from childcare, childcare provided 36.2% of their foods and drinks. The majority of foods and drinks came from stores for all children (53.2% among those receiving anything from childcare and 84.9% among those not). Among children receiving food from childcare, childcare is an important source of foods and drinks. Because most foods and drinks consumed by children come from stores, parents and caregivers may benefit from nutrition education to promote healthful choices when buying foods. |
Impacts of Hurricanes Irma and Maria on Aedes aegypti populations, aquatic habitats, and mosquito infections with dengue, chikungunya, and Zika viruses in Puerto Rico
Barrera R , Felix G , Acevedo V , Amador M , Rodriguez D , Rivera L , Gonzalez O , Nazario N , Ortiz M , Munoz JL , Waterman S , Hemme RR . Am J Trop Med Hyg 2019 100 (6) 1413-1420 Puerto Rico was severely impacted by Hurricanes Irma and Maria in September 2017. The island has been endemic for dengue viruses (DENV) and recently suffered epidemics of chikungunya (CHIKV 2014) and Zika (ZIKV 2016) viruses. Although severe storms tend to increase the number of vector and nuisance mosquitoes, we do not know how they influence Aedes aegypti populations and arboviral transmission. We compared the abundance of female Ae. aegypti in autocidal gravid ovitraps (AGO traps), container habitats, and presence of RNA of DENV, CHIKV, and ZIKV in this vector before and after the hurricanes in Caguas city and in four communities in southern Puerto Rico. Two of these communities were under vector control using mass AGO trapping and the other two nearby communities were not. We also investigated mosquito species composition and relative abundance (females/trap) using BG-2 traps in 59 sites in metropolitan San Juan city after the hurricanes. Mosquitoes sharply increased 5 weeks after Hurricane Maria. Ensuing abundance of Ae. aegypti was higher in Caguas and in one of the southern communities without vector control. Aedes aegypti did not significantly change in the two areas with vector control. The most abundant mosquitoes among the 26 species identified in San Juan were Culex (Melanoconion) spp., Culex quinquefasciatus, Culex nigripalpus, and Ae. aegypti. No arboviruses were detected in Ae. aegypti following the hurricanes, in contrast with observations from the previous year, so that the potential for Aedes-borne arboviral outbreaks following the storms in 2017 was low. |
Association of maternity care practices and policies with in-hospital exclusive breastfeeding in the United States
Barrera CM , Beauregard JL , Nelson JM , Perrine CG . Breastfeed Med 2019 14 (4) 243-248 BACKGROUND: Experiences during the birth hospitalization affect breastfeeding outcomes. In the United States, hospital policies and practices supportive of breastfeeding are routinely assessed through the Maternity Practices in Infant Nutrition and Care (mPINC) survey; however, mPINC does not capture data on breastfeeding outcomes. MATERIALS AND METHODS: Data from the 2015 mPINC survey were linked to 2015 data from the Joint Commission (TJC), a major accreditor of health care systems in the United States (n = 1,305 hospitals). Each hospital participating in mPINC is given a total score, which is the average of seven subscores; all ranging from 0 to 100. TJC has hospital-specific data on the percentage of infants exclusively breastfeeding at hospital discharge. We used linear regression to estimate differences between quartiles of (1) total mPINC score and (2) each mPINC subscore with rates of exclusive breastfeeding at hospital discharge, adjusting for hospital type, teaching status, and number of annual births. We additionally used linear models to test for trend across quartiles of mPINC score. RESULTS: The mean percentage of in-hospital exclusive breastfeeding increased from 39.0% for hospitals in the lowest mPINC total score quartile (<75) to 60.4% for hospitals in the highest mPINC total score quartile (>/=89), an adjusted difference of 21.1 percentage points (95% confidence interval 18.6-23.6). The mean percentage of in-hospital exclusive breastfeeding significantly increased (p < 0.0001) as mPINC scores increased for total mPINC score and for each mPINC subscore. CONCLUSIONS: Higher mPINC scores were associated with higher rates of in-hospital exclusive breastfeeding. Hospitals can make improvements to their maternity care practices and policies to support breastfeeding. |
Entomological investigation of Aedes aegypti in neighborhoods with confirmed human arbovirus infection in Puerto Rico
Felix GE , Barrera R , Vazquez J , Ryff KR , Munoz-Jordan JL , Matias KY , Hemme RR . J Am Mosq Control Assoc 2018 34 (3) 233-236 The exotic arboviruses chikungunya (CHIKV) and Zika (ZIKV) recently caused large outbreaks and continue to circulate in Puerto Rico, prompting entomological investigations at 9 locations with confirmed CHIKV- or ZIKV-infected human cases. Adult mosquitoes were collected using the Centers for Disease Control and Prevention autocidal gravid ovitraps over a 14-day period at each site. Mean female Aedes aegypti captured per trap-week ranged from 13.47 per trap-week to 1.27 per trap-week. Arbovirus-positive pools were detected at 7 of the 9 sampling sites. We investigated vertical transmission by collecting Ae. aegypti eggs in a single location where ZIKV was found in adult mosquitoes. We discuss the relationship between vector density and infection rates and its implications for determining mosquito density thresholds of novel invasive arboviruses such as CHIKV and ZIKV. |
Citywide control of Aedes aegypti (Diptera: Culicidae) during the 2016 Zika epidemic by integrating community awareness, education, source reduction, larvicides, and mass mosquito trapping
Barrera R , Harris A , Hemme RR , Felix G , Nazario N , Munoz-Jordan JL , Rodriguez D , Miranda J , Soto E , Martinez S , Ryff K , Perez C , Acevedo V , Amador M , Waterman SH . J Med Entomol 2019 56 (4) 1033-1046 This investigation was initiated to control Aedes aegypti and Zika virus transmission in Caguas City, Puerto Rico, during the 2016 epidemic using Integrated Vector Management (IVM), which included community awareness and education, source reduction, larviciding, and mass-trapping with autocidal gravid ovitraps (AGO). The epidemic peaked in August to October 2016 and waned after April 2017. There was a preintervention period in October/November 2016 and IVM lasted until August 2017. The area under treatment (23.1 km2) had 61,511 inhabitants and 25,363 buildings. The city was divided into eight even clusters and treated following a cluster randomized stepped-wedge design. We analyzed pools of female Ae. aegypti adults for RNA detection of dengue (DENV), chikungunya (CHIKV), and Zika (ZIKV) viruses using 360 surveillance AGO traps every week. Rainfall, temperature, and relative humidity were monitored in each cluster. Mosquito density significantly changed (generalized linear mixed model; F8, 14,588 = 296; P < 0.001) from 8.0 +/- 0.1 females per trap per week before the intervention to 2.1 +/- 0.04 after the percentage of buildings treated with traps was 60% and to 1.4 +/- 0.04 when coverage was above 80%. Out of a total 12,081 mosquito pools, there were 1 DENV-, 7 CHIKV-, and 49 ZIKV-positive pools from October 2016 to March 2017. Afterward, we found only one positive pool of DENV in July 2017. This investigation demonstrated that it was possible to scale up effective Ae. aegypti control to a medium-size city through IVM that included mass trapping of gravid Ae. aegypti females. |
Fertility treatment use and breastfeeding outcomes
Barrera CM , Kawwass JF , Boulet SL , Nelson JM , Perrine CG . Am J Obstet Gynecol 2018 220 (3) 261 e1-261 e7 BACKGROUND: About 15% of women aged 15-44 in the US experience infertility. Factors associated with infertility and fertility treatments may also be associated with lactation difficulties. Limited data exist examining the impact of infertility or mode of conception on breastfeeding outcomes. OBJECTIVE: The objectives of this study were to report breastfeeding outcomes (initiation and duration at 8 weeks) among women who conceived spontaneously compared to women who conceived using fertility treatments (assisted reproductive technology, intrauterine insemination, or fertility-enhancing drugs). STUDY DESIGN: Maternal-reported data from four states from the 2012-2015 Pregnancy Risk Assessment and Monitoring System (PRAMS) were used to explore use of fertility treatment and breastfeeding initiation and continuation at 8 weeks (n=15,615). Data were weighted to represent all women delivering live births within each state; SAS survey procedures were used to account for PRAMS complex survey design. Stepwise, multivariable logistic regression, adjusted for maternal demographics, parity, plurality, mode of delivery, preterm birth, and maternal pre-pregnancy health conditions, was used to quantify the associations between fertility treatment use and breastfeeding. RESULTS: Mode of conception was not associated with breastfeeding outcomes when comparing women who conceived spontaneously to women who conceived using any fertility treatment. The odds of breastfeeding at 8 weeks were lower among women who conceived using assisted reproductive technology, after adjusting for basic demographic covariates (aOR: 0.71; 95% CI: 0.52-0.97) and additionally adjusting for maternal health conditions (aOR: 0.68; 95% CI: 0.49-0.93), but this difference was no longer significant after adjusting for plurality and preterm birth (aOR: 0.74; 95% CI: 0.54-1.02). CONCLUSIONS: This study suggests that mothers who conceive using assisted reproductive technology may breastfeed for shorter durations than mothers who conceive spontaneously, partially mediated by an increased likelihood of multiples and infants born preterm. Studies are needed to elucidate these associations and to understand the intentions and barriers to breastfeeding among women who conceive with the help of assisted reproductive technology. |
- Page last reviewed:Feb 1, 2024
- Page last updated:Apr 22, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure