AEDES AEGYPTI KNOCKDOWN RESISTANCE MUTATIONS AND DENGUE VIRUS INFECTION IN HAITI.

Haiti is home to approximately 11 million people and has a high incidence of vector-borne disease, including more than 70,000 cases of dengue per year. Vector control is difficult in Haiti and adulticide spray of malathion is the main method of control employed during the outbreak of disease although pyrethroids are used in both bed net campaigns and in widely available aerosol cans for personal use. However, limited pathogen or insecticide resistance surveillance data are available for making operational decisions. In this study, we assessed Aedes aegypti from serial surveillance collections from 3 locations for the presence of dengue virus serotypes 1-3 (DENV1-3) by polymerase chain reaction and assessed, by melt curve analysis, samples from 10 locations in 2 departments for the presence of two mutations (V1016I and F1534C), that in combination, are linked to strong pyrethroid insecticide resistance. Only one of the 32 tested pools was positive for the presence of dengue virus. The two knockdown resistance (kdr) mutations were present in all locations. The 1016I mutation frequency varied from 0.29 to 0.91 and was in all sites lower than the 0.58-1.00 frequency of the 1534C mutation. We also observed that the genotype homozygous for both mutations (IICC), which has been linked to strong pyrethroid resistance, varied from 13 to 86% in each population. Notably, 3 locations - Ti Cousin and Christianville in Ouest department and Camp Coq in Nord department had more than 30% of the tested population without the presence of kdr mutations. These results indicate that the kdr markers of pyrethroid resistance are present in Haiti, at high frequency in several locations and, based on previous studies linking kdr genotypes and phenotypic resistance, that operational interventions with pyrethroids are not likely to be as effective as expected.

Understanding transmission risk and predicting environmental suitability for Mayaro Virus in Central and South America.

Mayaro virus (MAYV) is a mosquito-borne Alphavirus that is widespread in South America. MAYV infection often presents with non-specific febrile symptoms but may progress to debilitating chronic arthritis or arthralgia. Despite the pandemic threat of MAYV, its true distribution remains unknown. The objective of this study was to clarify the geographic distribution of MAYV using an established risk mapping framework. This consisted of generating evidence consensus scores for MAYV presence, modeling the potential distribution of MAYV in select countries across Central and South America, and estimating the population residing in areas suitable for MAYV transmission. We compiled a georeferenced compendium of MAYV occurrence in humans, animals, and arthropods. Based on an established evidence consensus framework, we integrated multiple information sources to assess the total evidence supporting ongoing transmission of MAYV within each country in our study region. We then developed high resolution maps of the disease's estimated distribution using a boosted regression tree approach. Models were developed using nine climatic and environmental covariates that are related to the MAYV transmission cycle. Using the output of our boosted regression tree models, we estimated the total population living in regions suitable for MAYV transmission. The evidence consensus scores revealed high or very high evidence of MAYV transmission in several countries including Brazil (especially the states of Mato Grosso and Goiás), Venezuela, Peru, Trinidad and Tobago, and French Guiana. According to the boosted regression tree models, a substantial region of South America is suitable for MAYV transmission, including north and central Brazil, French Guiana, and Suriname. Some regions (e.g., Guyana) with only moderate evidence of known transmission were identified as highly suitable for MAYV. We estimate that approximately 58.9 million people (95% CI: 21.4-100.4) in Central and South America live in areas that may be suitable for MAYV transmission, including 46.2 million people (95% CI: 17.6-68.9) in Brazil. Our results may assist in prioritizing high-risk areas for vector control, human disease surveillance and ecological studies.

Does prior exposure to larvicides influence dengue virus susceptibility in Aedes aegypti (Diptera: Culicidae)?

Control of mosquito vector populations is primarily intended to reduce the transmission of pathogens they transmit. Use of chemical controls, such as larvicides, can have unforeseen consequences on adult traits if not applied properly. The consequences of under application of larvicides are little studied, specifically the impacts on pathogen infection and transmission by the vectors that survive exposure to larvicides. We compared vector susceptibility of Aedes aegypti (L.) for dengue virus, serotype 1 (DENV-1) previously exposed as larvae to an LC50 of different classes of insecticides as formulated larvicides. Larval exposure to insect growth regulators (methoprene and pyriproxyfen) significantly increased susceptibility to infection of DENV-1 in Ae. aegypti adults but did not alter disseminated infection or transmission. Larval exposure to temephos, spinosad, and Bti did not increase infection, disseminated infection, or transmission of DENV-1. Our findings describe a previously under observed phenomenon, the latent effects of select larvicides on mosquito vector susceptibility for arboviruses. These data suggest that there are unintended consequences of sublethal exposure to select larvicides that can influence susceptibility of Ae. aegypti to DENV infection, and indicates the need for further investigation of sublethal effects of insecticides on other aspects of mosquito biology, especially those parameters relevant to a mosquitoes ability to transmit arboviruses (life span, biting behavior, extrinsic incubation period).

A geopositioned and evidence-graded pan-species compendium of Mayaro virus occurrence.

Mayaro Virus (MAYV) is an emerging health threat in the Americas that can cause febrile illness as well as debilitating arthralgia or arthritis. To better understand the geographic distribution of MAYV risk, we developed a georeferenced database of MAYV occurrence based on peer-reviewed literature and unpublished reports. Here we present this compendium, which includes both point and polygon locations linked to occurrence data documented from its discovery in 1954 until 2022. We describe all methods used to develop the database including data collection, georeferencing, management and quality-control. We also describe a customized grading system used to assess the quality of each study included in our review. The result is a comprehensive, evidence-graded database of confirmed MAYV occurrence in humans, non-human animals, and arthropods to-date, containing 262 geo-positioned occurrences in total. This database - which can be updated over time - may be useful for local spill-over risk assessment, epidemiological modelling to understand key transmission dynamics and drivers of MAYV spread, as well as identification of major surveillance gaps.

Lethal and Sublethal Concentrations of Formulated Larvicides Against Susceptible Aedes aegypti.

Chemical control of vectors depends on the effective application of formulated insecticides. In this study we evaluated formulated larvicides using a larval bioassay against susceptible Aedes aegypti. The estimated larvicide lethal concentrations for 50% mortality (LC50s) were 25.7 µg/liter (Natular 2EC), 3.13 µg/liter (Abate 4E), 0.43 µg/liter (Altosid), 0.03 µg/liter (Nyguard), and 500.6 ITU/liter (VectoBac12AS containing Bacillus thuringiensis israelensis). Sublethal effects were identified and documented from adults that survived exposure to these estimated LC50s (body size and sex proportion). We observed changes in net growth as measured by adult wing lengths. For those larvae exposed to estimated LC50s, the average size of adults was between 0.1% and 10.6% smaller for males and between 1.1% and 13.6% smaller for females compared to controls. Sex proportions varied between larvicides, but some were significantly different from the control, favoring greater survival of females than males.

Analysis of Zika Virus Sequence Data Associated with a School Cohort in Haiti.

Zika virus (ZIKV) infections occurred in epidemic form in the Americas in 2014-2016, with some of the earliest isolates in the region coming from Haiti. We isolated ZIKV from 20 children with acute undifferentiated febrile illness who were part of a cohort of children seen at a school clinic in the Gressier region of Haiti. The virus was also isolated from three pools of Aedes aegypti mosquitoes collected at the same location. On phylogenetic analysis, three distinct ZIKV clades were identified. Strains from all three clades were present in Haiti in 2014, making them among the earliest isolates identified in the Western Hemisphere. Strains from all three clades were also isolated in 2016, indicative of their persistence across the time period of the epidemic. Mosquito isolates were collected in 2016 and included representatives from two of the three clades; in one instance, ZIKV was isolated from a pool of male mosquitoes, suggestive of vertical transmission of the virus. The identification of multiple ZIKV clades in Haiti at the beginning of the epidemic suggests that Haiti served as a nidus for transmission within the Caribbean.

A systematic review and meta-analysis of the potential non-human animal reservoirs and arthropod vectors of the Mayaro virus.

Improving our understanding of Mayaro virus (MAYV) ecology is critical to guide surveillance and risk assessment. We conducted a PRISMA-adherent systematic review of the published and grey literature to identify potential arthropod vectors and non-human animal reservoirs of MAYV. We searched PubMed/MEDLINE, Embase, Web of Science, SciELO and grey-literature sources including PAHO databases and dissertation repositories. Studies were included if they assessed MAYV virological/immunological measured occurrence in field-caught, domestic, or sentinel animals or in field-caught arthropods. We conducted an animal seroprevalence meta-analysis using a random effects model. We compiled granular georeferenced maps of non-human MAYV occurrence and graded the quality of the studies using a customized framework. Overall, 57 studies were eligible out of 1523 screened, published between the years 1961 and 2020. Seventeen studies reported MAYV positivity in wild mammals, birds, or reptiles and five studies reported MAYV positivity in domestic animals. MAYV positivity was reported in 12 orders of wild-caught vertebrates, most frequently in the orders Charadriiformes and Primate. Sixteen studies detected MAYV in wild-caught mosquito genera including Haemagogus, Aedes, Culex, Psorophora, Coquillettidia, and Sabethes. Vertebrate animals or arthropods with MAYV were detected in Brazil, Panama, Peru, French Guiana, Colombia, Trinidad, Venezuela, Argentina, and Paraguay. Among non-human vertebrates, the Primate order had the highest pooled seroprevalence at 13.1% (95% CI: 4.3-25.1%). From the three most studied primate genera we found the highest seroprevalence was in Alouatta (32.2%, 95% CI: 0.0-79.2%), followed by Callithrix (17.8%, 95% CI: 8.6-28.5%), and Cebus/Sapajus (3.7%, 95% CI: 0.0-11.1%). We further found that MAYV occurs in a wide range of vectors beyond Haemagogus spp. The quality of evidence behind these findings was variable and prompts calls for standardization of reporting of arbovirus occurrence. These findings support further risk emergence prediction, guide field surveillance efforts, and prompt further in-vivo studies to better define the ecological drivers of MAYV maintenance and potential for emergence.

Investigations of socioeconomic factors associated with follow-up compliance with malaria treatment in Haiti.

OBJECTIVE: To identify factors affecting compliance with follow-up during treatment in confirmed malaria patients at two health centers in Haiti. METHODS: A prospective observational study of malaria patients undergoing treatment over a six-week period. Patients' return visits (follow-up visits) to the health centers for consultation in accordance with the physicians' requests were recorded and used to determine compliance. Socioeconomic data were obtained from patient enrollment questionnaires and through post-treatment interviews. The management practices and procedures at the health centers to retain patients were also reviewed. Descriptive statistics and Spearman's rank correlation were used to identify significant factors, which were used as variables in a logistic regression model. RESULTS: Sixty-eight percent of the malaria patients completed follow-up, with higher compliance being recorded in the larger, more established health center of Leogane (67%) than Cite Soleil (33%). The patient socioeconomic profiles differed between the two health center locations by level of education, religious diversity, household size, and percentage of married individuals. Crude logistic regression analyses identified health center location (OR = 0.179 [95% CI 0.064, 0.504]) and household size (OR = 1.374 [95% CI 1.056, 1.787]) to be associated with compliance. The adjusted model only identified health center location (OR = 0.226 [95% CI 0.056, 0.918]) as significantly associated with compliance. CONCLUSION: Although patients' household size may be important according to the crude logistic regression analysis, in the adjusted analysis the site location of the health center where patients receive treatment was identified as the only important factor associated with follow-up compliance in malaria patients during treatment in Haiti. This information might be helpful to improve treatment outcomes and contribute to the monitoring of antimalarial resistance in Haiti.

Investigations of socioeconomic factors associated with follow-up compliance with malaria treatment in Haiti

[ABSTRACT]. Objective. To identify factors affecting compliance with follow-up during treatment in confirmed malaria patients at two health centers in Haiti. Methods. A prospective observational study of malaria patients undergoing treatment over a six-week period. Patients’ return visits (follow-up visits) to the health centers for consultation in accordance with the physicians’ requests were recorded and used to determine compliance. Socioeconomic data were obtained from patient enrollment questionnaires and through post-treatment interviews. The management practices and procedures at the health centers to retain patients were also reviewed. Descriptive statistics and Spearman’s rank correlation were used to identify significant factors, which were used as variables in a logistic regression model. Results. Sixty-eight percent of the malaria patients completed follow-up, with higher compliance being recorded in the larger, more established health center of Leogane (67%) than Cite Soleil (33%). The patient socioeconomic profiles differed between the two health center locations by level of education, religious diversity, household size, and percentage of married individuals. Crude logistic regression analyses identified health center location (OR = 0.179 [95% CI 0.064, 0.504]) and household size (OR = 1.374 [95% CI 1.056, 1.787]) to be associated with compliance. The adjusted model only identified health center location (OR = 0.226 [95% CI 0.056, 0.918]) as significantly associated with compliance. Conclusion. Although patients’ household size may be important according to the crude logistic regression analysis, in the adjusted analysis the site location of the health center where patients receive treatment was identified as the only important factor associated with follow-up compliance in malaria patients during treatment in Haiti. This information might be helpful to improve treatment outcomes and contribute to the monitoring of antimalarial resistance in Haiti.

[RESUMEN]. Objetivo. Determinar los factores que afectan el cumplimiento del seguimiento durante el tratamiento de los pacientes con malaria confirmada en dos centros de salud de Haití. Métodos. Se llevó a cabo un estudio observacional prospectivo de los pacientes con malaria que recibían tratamiento a lo largo de un período de seis semanas. Se registraron las consultas subsiguientes de los pacientes a los centros de salud (consultas de seguimiento) de acuerdo con la solicitud de los médicos, que se emplearon para determinar el cumplimiento. Se obtuvieron los datos socioeconómicos de los cuestionarios del registro de pacientes y mediante entrevistas postratamiento. También se examinaron las prácticas y los procedimientos de gestión del centro de salud para promover la retención de los pacientes. Se emplearon estadísticas descriptivas y la correlación de rangos de Spearman para determinar los factores significativos, que se usaron como variables en un modelo de regresión logística. Resultados. El 68% de los enfermos de malaria completaron el seguimiento. El mayor cumplimiento se registró en el centro de salud más grande y de mayor prestigio de Léogâne (67%) en comparación con el centro de Cité Soleil (33%). Los perfiles socioeconómicos de los pacientes difirieron entre las dos ubicaciones del centro de salud en lo concerniente al nivel de escolaridad, diversidad religiosa, tamaño del hogar y porcentaje de personas casadas. Los análisis crudos de regresión logística determinaron que había una asociación entre la ubicación del centro de salud (OR = 0,179 [IC de 95 % 0,064, 0,504]) y el tamaño del hogar (OR = 1,374 [IC de 95 % 1,056, 1,787]) con el cumplimiento. En el modelo ajustado se encontró que solo la ubicación del centro de salud (OR = 0,226 [IC de 95 % 0,056, 0,918]) estaba significativamente relacionada con el cumplimiento. Conclusión. Aunque el tamaño del hogar de los pacientes podría ser importante según el análisis crudo de regresión logística, en el análisis ajustado se determinó que la ubicación del centro de salud en que los pacientes reciben el tratamiento era el único factor importante asociado con el cumplimiento de seguimiento de los pacientes con malaria en tratamiento en Haití. Es posible que esta información sea útil para mejorar los resultados del tratamiento y contribuir al seguimiento de la resistencia a los antimaláricos en Haití.

[RESUMO]. Objetivo. Identificar os fatores que afetam a adesão ao seguimento durante o tratamento da malária em pacientes com diagnóstico confirmado em dois centros de saúde no Haiti. Métodos. Estudo observacional prospectivo de pacientes com malária em tratamento durante um período de seis semanas. Os retornos dos pacientes (consultas de seguimento) aos centros de saúde para consulta, conforme solicitado pelos médicos, foram registrados e usados para determinar a adesão. Os dados socioeconômicos foram obtidos a partir dos cadastros dos pacientes e por meio de entrevistas pós-tratamento. As práticas e procedimentos de gestão para reter pacientes no centro de saúde também foram analisados. Foram utilizadas estatísticas descritivas e correlação de Spearman para identificar fatores significativos, que foram então incluídos como variáveis em um modelo de regressão logística. Resultados. Sessenta e oito por cento dos pacientes com malária concluíram o seguimento. A adesão foi superior no centro de saúde maior e mais estabelecido de Léogâne (67%) do que no de Cité Soleil (33%). Os perfis socioeconômicos dos pacientes nos dois centros de saúde divergiram em relação à escolaridade, diversidade religiosa, tamanho da família e porcentagem de indivíduos casados. As análises de regressão logística brutas identificaram a localização do centro de saúde (OR = 0,179 [IC 95% 0,064; 0,504]) e o número de residentes no domicílio (OR = 1,374 [IC 95% 1,056; 1,787]) como fatores associados à adesão. O modelo ajustado identificou apenas a localização do centro de saúde (OR = 0,226 [IC 95% 0,056; 0,918]) como fator significativamente associado à conformidade. Conclusão. Embora o número de residentes no domicílio dos pacientes possa ser importante de acordo com a análise de regressão logística bruta, na análise ajustada a localização do centro de saúde onde os pacientes receberam tratamento foi identificada como o único fator importante associado à adesão ao seguimento em pacientes com malária durante o tratamento no Haiti. Essas informações podem ser úteis para melhorar os desfechos do tratamento e contribuir para o monitoramento da resistência aos antimaláricos no Haiti.

Genetic Markers of Adaptation of Plasmodium falciparum to Transmission by American Vectors Identified in the Genomes of Parasites from Haiti and South America.

The malaria parasite, Plasmodium falciparum, was introduced into Hispaniola and other regions of the Americas through the slave trade spanning the 16th through the 19th centuries. During this period, more than 12 million Africans were brought across the Atlantic to the Caribbean and other regions of the Americas. Since malaria is holoendemic in West Africa, a substantial percentage of these individuals carried the parasite. St. Domingue on Hispaniola, now modern-day Haiti, was a major port of disembarkation, and malaria is still actively transmitted there. We undertook a detailed study of the phylogenetics of the Haitian parasites and those from Colombia and Peru utilizing whole-genome sequencing. Principal-component and phylogenetic analyses, based upon single nucleotide polymorphisms (SNPs) in protein coding regions, indicate that, despite the potential for millions of introductions from Africa, the Haitian parasites share an ancestral relationship within a well-supported monophyletic clade with parasites from South America, while belonging to a distinct lineage. This result, in stark contrast to the historical record of parasite introductions, is best explained by a severe population bottleneck experienced by the parasites introduced into the Americas. Here, evidence is presented for targeted selection of rare African alleles in genes which are expressed in the mosquito stages of the parasite's life cycle. These genetic markers support the hypothesis that the severe population bottleneck was caused by the required adaptation of the parasite to transmission by new definitive hosts among the Anopheles (Nyssorhynchus) spp. found in the Caribbean and South America.IMPORTANCE Historical data suggest that millions of P. falciparum parasite lineages were introduced into the Americas during the trans-Atlantic slave trade, which would suggest a paraphyletic origin of the extant isolates in the Western Hemisphere. Our analyses of whole-genome variants show that the American parasites belong to a well-supported monophyletic clade. We hypothesize that the required adaptation to American vectors created a severe bottleneck, reducing the effective introduction to a few lineages. In support of this hypothesis, we discovered genes expressed in the mosquito stages of the life cycle that have alleles with multiple, high-frequency or fixed, nonsynonymous mutations in the American populations which are rarely found in African isolates. These alleles appear to be in gene products critical for transmission through the anopheline vector. Thus, these results may inform efforts to develop novel transmission-blocking vaccines by identifying parasite proteins functionally interacting with the vector that are important for successful transmission. Further, to the best of our knowledge, these are the first whole-genome data available from Haitian P. falciparum isolates. Defining the genome of these parasites provides genetic markers useful for mapping parasite populations and monitoring parasite movements/introductions.

Emergence of Madariaga virus as a cause of acute febrile illness in children, Haiti, 2015-2016.

Madariaga virus (MADV), also known as South American eastern equine encephalitis virus, has been identified in animals and humans in South and Central America, but not previously in Hispaniola or the northern Caribbean. MADV was isolated from virus cultures of plasma from an 8-year-old child in a school cohort in the Gressier/Leogane region of Haiti, who was seen in April, 2015, with acute febrile illness (AFI). The virus was subsequently cultured from an additional seven AFI case patients from this same cohort in February, April, and May 2016. Symptoms most closely resembled those seen with confirmed dengue virus infection. Sequence data were available for four isolates: all were within the same clade, with phylogenetic and molecular clock data suggesting recent introduction of the virus into Haiti from Panama sometime in the period from October 2012-January 2015. Our data document the movement of MADV into Haiti, and raise questions about the potential for further spread in the Caribbean or North America.

Seroepidemiology of Burkholderia pseudomallei, Etiologic Agent of Melioidosis, in the Ouest and Sud-Est Departments of Haiti.

Burkholderia pseudomallei, the etiological agent of melioidosis, has been hypothesized to be endemic throughout the Caribbean, including the impoverished nation of Haiti. However, because of the protean clinical manifestations, presence of asymptomatic infections, and limited medical diagnostic capacity, the identification of active melioidosis cases remains challenging. A seroepidemiological study was conducted using a novel enzyme-linked immunosorbent assay (ELISA) to detect antibodies toward B. pseudomallei in the native population. The performance of an indirect ELISA with purified lipopolysaccharide (LPS) from B. pseudomallei was evaluated using serum collected from rhesus macaques exposed to aerosolized B. pseudomallei. After optimization, serum collected from asymptomatic population members (n = 756) was screened for polyvalent (immunoglobulin M [IgM]/ immunoglobulin G [IgG]/ immunoglobulin A) and monoclonal (IgG or IgM) immunoglobulins against B. pseudomallei LPS. The population seroprevalence was 11.5% (95% confidence interval [CI]: 9.2, 13.8) for polyvalent immunoglobulins, 9.8% (95% CI: 7.7, 11.9) for IgG, and 1.7% (95% CI: 0.8, 2.6%) for IgM. The seroprevalence was not significantly different by gender (P = 0.16), but increased significantly (P < 0.001) with age, yielding an estimated annual seroconversion rate of 1.05% (95% CI: 0.81, 1.3). The detection of both recent (IgM+) and previous (IgG+) exposure to B. pseudomallei provides serological evidence that melioidosis is endemic in Haiti.

Spondweni Virus in Field-Caught Culex quinquefasciatus Mosquitoes, Haiti, 2016.

Spondweni virus (SPONV) and Zika virus cause similar diseases in humans. We detected SPONV outside of Africa from a pool of Culex mosquitoes collected in Haiti in 2016. This finding raises questions about the role of SPONV as a human pathogen in Haiti and other Caribbean countries.

A new "American" subgroup of African-lineage Chikungunya virus detected in and isolated from mosquitoes collected in Haiti, 2016.

As part of on-going arboviral surveillance activity in a semi-rural region in Haiti, Chikungunya virus (CHIKV)-positive mosquito pools were identified in 2014 (the peak of the Caribbean Asian-clade epidemic), and again in 2016 by RT-PCR. In 2014, CHIKV was only identified in Aedes aegypti (11 positive pools/124 screened). In contrast, in sampling in 2016, CHIKV was not identified in Ae. aegypti, but, rather, in (a) a female Aedes albopictus pool, and (b) a female Culex quinquefasciatus pool. Genomic sequence analyses indicated that the CHIKV viruses in the 2016 mosquito pools were from the East-Central-South African (ECSA) lineage, rather than the Asian lineage. In phylogenetic studies, these ECSA lineage strains form a new ECSA subgroup (subgroup IIa) together with Brazilian ECSA lineage strains from an isolated human outbreak in 2014, and a mosquito pool in 2016. Additional analyses date the most recent common ancestor of the ECSA IIa subgroup around May 2007, and the 2016 Haitian CHIKV genomes around December 2015. Known CHIKV mutations associated with improved Ae. albopictus vector competence were not identified. Isolation of this newly identified lineage from Ae. albopictus is of concern, as this vector has a broader geographic range than Ae. aegypti, especially in temperate areas of North America, and stresses the importance for continued vector surveillance.

Cross-sectional analysis of the association between bedtime and malaria exposure in the Ouest and Sud-Est Departments of Haiti.

INTRODUCTION: The governments of Haiti and the Dominican Republic have a binational agreement to work towards malaria elimination for the island of Hispaniola by the year 2020. Understanding malaria-related knowledge and behaviors can help inform elimination efforts. This study examined the association between social-behavioral factors, like bedtime and bed net ownership, with malaria seroconversion status among people in the Ouest and Sud-Est departments of Haiti. METHODS: In 2013, cross-sectional survey data (n=377) and blood samples were collected from a convenience sample of individuals within community, clinic and school settings. Logistic regression models were constructed to examine associations between social-behavioral factors and malaria exposure, adjusting for potential confounders. RESULTS: Compared to people going to bed between 6 and 8 pm, those going to bed between 8 and 10 pm were 2.67 (OR, 95% CI: 1.16-6.14) times as likely to have been exposed to malaria. Participants who reported going to bed after 10 pm were 5.96 times as likely to have had previous malaria exposure (OR, 95% CI: 2.26-15.7), compared to 6-8 pm. No significant associations were found between malaria exposure and either insecticide use nor bed net ownership. DISCUSSION: These findings are consistent with suspected feeding behaviors of Anopheles albimanus, which prefers feeding at night and outdoors. Study findings may improve overall understanding of malaria transmission in Haiti and potentially guide future studies conducted in this region.

Field Trial of the CareStart Biosensor Analyzer for the Determination of Glucose-6-Phosphate Dehydrogenase Activity in Haiti.

Throughout many developing and tropical countries around the world, malaria remains a significant threat to human health. One barrier to malaria elimination is the ability to safely administer primaquine chemotherapy for the radical cure of malaria infections in populations with a high prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency. In the current study, a field trial of the world's first quantitative, point-of-care assay for measuring G6PD activity was conducted in Haiti. The performance of the CareStart Biosensor Analyzer was compared with the gold standard spectrophotometric assay and genotyping of the G6PD allele in schoolchildren (N = 343) from the Ouest Department of Haiti. In this population, 19.5% of participants (67/343) had some form of G6PD deficiency (< 60% residual activity) and 9.9% (34/343) had moderate-to-severe G6PD deficiency (< 30% residual activity). Overall, 18.95% of participants had the presence of the A-allele (65/343) with 7.87% (27/343) considered at high risk for drug-induced hemolysis (hemizygous males and homozygous females). Compared with the spectrophotometric assay, the sensitivity and specificity to determine participants with < 60% residual activity were 53.7% and 94.6%, respectively; for participants with 30% residual activity, the sensitivity and specificity were 5.9% and 99.7%, respectively. The biosensor overestimated the activity in deficient individuals and underestimated it in participants with normal G6PD activity, indicating the potential for a systematic measurement error. Thus, we suggest that the current version of the biosensor lacks adequate sensitivity and should be improved prior to its use as a point-of-care diagnostic for G6PD deficiency.

Complete Genomic Sequence of Dengue virus 1, Isolated from Plasma Collected from a Haitian Child in 2014.

An outbreak of dengue fever followed a chikungunya fever outbreak in Haiti in 2014. We detected Dengue virus 1 (DENV-1) in plasma samples collected between May 2014 and February 2015. A representative isolate was fully sequenced, and phylogenetic analyses indicate that it groups within the genotype V South American and Caribbean DENV-1 clades.

Submicroscopic malaria infections in pregnant women from six departments in Haiti.

OBJECTIVES: To describe the epidemiology of malaria in pregnancy in Haiti. METHODS: Cross-sectional study among pregnant women in six departments of Haiti. After obtaining informed consent, whole blood samples and demographic surveys were collected to investigate malaria prevalence, anaemia and socio-behavioural risk factors for infection, respectively. A total of 311 pregnant women were screened for Plasmodium falciparum infection using a rapid diagnostic test (RDT), microscopy and a novel, quantitative reverse transcriptase polymerase chain reaction method (qRT-PCR). RESULTS: Overall, 1.2% (4/311) of pregnant women were tested positive for malaria infection by both microscopy and RDT. However, using the qRT-PCR, 16.4% (51/311) of pregnant women were positive. The prevalence of malaria infection varied with geographical locations ranging between 0% and 46.4%. Additionally, 53% of pregnant women had some form of anaemia; however, no significant association was found between anaemia and submicroscopic malaria infection. The socio-behavioural risk factors identified to be protective of malaria infection were marital status (P < 0.05) and travel within one month prior to screening (P < 0.05). CONCLUSION: This study is the first to document the high prevalence of submicroscopic malaria infections among pregnant women in Haiti and identify social and behavioural risk factors for disease transmission.

Complete Genome Sequences of Chikungunya Viruses Isolated from Plasma Specimens Collected from Haitians in 2014.

Ten chikungunya virus isolates from human plasma collected in Haiti from May to August 2014, in the midst of a chikungunya fever outbreak, were fully sequenced. The resulting genomic sequences are nearly identical, and phylogenetic analyses indicate they belong to the Asian lineage of the virus.

Isolation of Coronavirus NL63 from Blood from Children in Rural Haiti: Phylogenetic Similarities with Recent Isolates from Malaysia.

Human coronavirus (HCoV) NL63 is recognized as a common cause of upper respiratory infections and influenza-like illness. In screening children with acute undifferentiated febrile illness in a school cohort in rural Haiti, we identified HCoV-NL63 in blood samples from four children. Cases clustered over an 11-day period; children did not have respiratory symptoms, but two had gastrointestinal complaints. On phylogenetic analysis, the Haitian HCoV-NL63 strains cluster together in a highly supported monophyletic clade linked most closely with recently reported strains from Malaysia; two respiratory HCoV-NL63 strains identified in north Florida in the same general period form a separate clade, albeit again with close linkages with the Malaysian strains. Our data highlight the variety of presentations that may be seen with HCoV-NL63, and underscore the apparent ease with which CoV strains move among countries, with our data consistent with recurrent introduction of strains into the Caribbean (Haiti and Florida) from Asia.