RESUMO
The 2010 cholera epidemic in Haiti was thought to have ended in 2019, and the Prime Minister of Haiti declared the country cholera-free in February 2022. On September 25, 2022, cholera cases were again identified in Port-au-Prince. We compared genomic data from 42 clinical Vibrio cholerae strains from 2022 with data from 327 other strains from Haiti and 1,824 strains collected worldwide. The 2022 isolates were homogeneous and closely related to clinical and environmental strains circulating in Haiti during 2012-2019. Bayesian hypothesis testing indicated that the 2022 clinical isolates shared their most recent common ancestor with an environmental lineage circulating in Haiti in July 2018. Our findings strongly suggest that toxigenic V. cholerae O1 can persist for years in aquatic environmental reservoirs and ignite new outbreaks. These results highlight the urgent need for improved public health infrastructure and possible periodic vaccination campaigns to maintain population immunity against V. cholerae.
Assuntos
Cólera , Vibrio cholerae , Humanos , Vibrio cholerae/genética , Haiti/epidemiologia , Teorema de Bayes , Cólera/epidemiologia , Surtos de DoençasRESUMO
Toxigenic Vibrio cholerae O1 serotype Ogawa was introduced involuntarily into Haiti in October 2010, and virtually all of the clinical strains isolated during the first 5 years of the epidemic were Ogawa. Inaba strains were identified intermittently prior to 2015, with diverse mutations resulting in a common phenotype. In 2015, the percentage of clinical infections due to the Inaba serotype began to rapidly increase, with Inaba supplanting Ogawa as the dominant serotype during the subsequent 4 years. We investigated the molecular basis of the serotype switch and confirmed that all Inaba strains had the same level of mRNA expression of the wbeT genes, as well as the same translation levels for the truncated WbeT proteins in the V. cholerae Inaba isolates. Neither wbeT gene expression levels, differential mutations, or truncation size of the WbeT proteins appeared to be responsible for the successful Inaba switch in 2015. Our phylodynamic analysis demonstrated that the V. cholerae Inaba strains in Haiti evolved directly from Ogawa strains and that a significant increase of diversifying selection at the population level occurred at the time of the Ogawa-Inaba switch. We conclude that the emergence of the Inaba serotype was driven by diversifying selection, independent of the mutational pattern in the wbeT gene. IMPORTANCE Our phylodynamic analysis demonstrated that Vibrio cholerae Inaba strains in Haiti evolved directly from Ogawa strains. Our results support the hypothesis that after an initial Ogawa-dominated epidemic wave, V. cholerae Inaba was able to become the dominant strain thanks to a selective advantage driven by ongoing diversifying selection, independently from the mutational pattern in the wbeT gene.
Assuntos
Cólera , Vibrio cholerae O1 , Humanos , Vibrio cholerae O1/genética , Sorogrupo , Cólera/epidemiologia , Haiti/epidemiologia , SorotipagemRESUMO
We isolated a novel coronavirus from a medical team member presenting with fever and malaise after travel to Haiti. The virus showed 99.4% similarity with a recombinant canine coronavirus recently identified in a pneumonia patient in Malaysia, suggesting that infection with this virus and/or recombinant variants occurs in multiple locations.
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COVID-19 , Coronavirus Canino , Animais , Cães , Haiti , Humanos , SARS-CoV-2/genética , ViagemRESUMO
After an initial wave of coronavirus disease 2019 (COVID-19) in Haiti in summer 2020 (primarily lineage B.1), seropositivity for anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) was ~40%. Variant P.1 (gamma) was introduced in February 2021, with an initially limited introduction followed by exponential local dissemination within this unvaccinated population with prior exposure to earlier SARS-CoV-2 lineages.
Assuntos
COVID-19 , SARS-CoV-2 , Teste para COVID-19 , Haiti/epidemiologia , Humanos , SARS-CoV-2/genéticaRESUMO
Coronaviruses have caused three major epidemics since 2003, including the ongoing SARS-CoV-2 pandemic. In each case, the emergence of coronavirus in our species has been associated with zoonotic transmissions from animal reservoirs1,2, underscoring how prone such pathogens are to spill over and adapt to new species. Among the four recognized genera of the family Coronaviridae, human infections reported so far have been limited to alphacoronaviruses and betacoronaviruses3-5. Here we identify porcine deltacoronavirus strains in plasma samples of three Haitian children with acute undifferentiated febrile illness. Genomic and evolutionary analyses reveal that human infections were the result of at least two independent zoonoses of distinct viral lineages that acquired the same mutational signature in the genes encoding Nsp15 and the spike glycoprotein. In particular, structural analysis predicts that one of the changes in the spike S1 subunit, which contains the receptor-binding domain, may affect the flexibility of the protein and its binding to the host cell receptor. Our findings highlight the potential for evolutionary change and adaptation leading to human infections by coronaviruses outside of the previously recognized human-associated coronavirus groups, particularly in settings where there may be close human-animal contact.
Assuntos
Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Deltacoronavirus/isolamento & purificação , Suínos/virologia , Zoonoses Virais/epidemiologia , Zoonoses Virais/virologia , Sequência de Aminoácidos , Animais , Teorema de Bayes , Criança , Chlorocebus aethiops , Sequência Conservada , Infecções por Coronavirus/sangue , Deltacoronavirus/classificação , Deltacoronavirus/genética , Deltacoronavirus/patogenicidade , Feminino , Haiti/epidemiologia , Humanos , Masculino , Modelos Moleculares , Mutação , Filogenia , Células Vero , Zoonoses Virais/sangueRESUMO
Coronaviruses have caused three major epidemics since 2003, including the ongoing SARS-CoV-2 pandemic. In each case, coronavirus emergence in our species has been associated with zoonotic transmissions from animal reservoirs 1,2 , underscoring how prone such pathogens are to spill over and adapt to new species. Among the four recognized genera of the family Coronaviridae - Alphacoronavirus, Betacoronavirus, Deltacoronavirus, Gammacoronavirus , - human infections reported to date have been limited to alpha- and betacoronaviruses 3 . We identify, for the first time, porcine deltacoronavirus (PDCoV) strains in plasma samples of three Haitian children with acute undifferentiated febrile illness. Genomic and evolutionary analyses reveal that human infections were the result of at least two independent zoonoses of distinct viral lineages that acquired the same mutational signature in the nsp15 and the spike glycoprotein genes by convergent evolution. In particular, structural analysis predicts that one of the changes in the Spike S1 subunit, which contains the receptor-binding domain, may affect protein's flexibility and binding to the host cell receptor. Our findings not only underscore the ability of deltacoronaviruses to adapt and potentially lead to human-to-human transmission, but also raise questions about the role of such transmissions in development of pre-existing immunity to other coronaviruses, such as SARS-CoV-2.
RESUMO
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.
Assuntos
Adaptação Fisiológica/genética , Anopheles/parasitologia , Variação Genética , Filogenia , Plasmodium falciparum/genética , Animais , Marcadores Genéticos , Haiti , Malária Falciparum/parasitologia , Mosquitos Vetores/parasitologia , Mutação , Plasmodium falciparum/classificação , Plasmodium falciparum/fisiologia , América do Sul , Estados Unidos , Sequenciamento Completo do GenomaRESUMO
While data are limited, there is increasing evidence that infections by dengue viruses are endemic in Haiti. In 2014, an outbreak caused by dengue virus 4 (DENV-4) followed a chikungunya fever outbreak. We present here the complete genome sequence of one isolate grouped within the genotype II South America and Caribbean DENV-4 clades.
RESUMO
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.
RESUMO
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.
Assuntos
Malária Falciparum/epidemiologia , Plasmodium falciparum , Complicações Infecciosas na Gravidez/epidemiologia , Adolescente , Adulto , Anemia/complicações , Estudos Transversais , Feminino , Haiti/epidemiologia , Humanos , Malária Falciparum/parasitologia , Malária Falciparum/transmissão , Estado Civil , Microscopia , Gravidez , Complicações Infecciosas na Gravidez/parasitologia , Prevalência , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Risco , Viagem , Adulto JovemRESUMO
BACKGROUND: Public health measures are poised for transition from malaria control to malaria elimination on the island of Hispaniola. Assessment of the reservoir of asymptomatic infections from which acute malaria cases may derive is critical to plan and evaluate elimination efforts. Current field technology is ill suited for detecting sub-microscopic infections, thus highly sensitive survey methods capable of detecting virtually all infections are needed. In this study the prevalence of infection with Plasmodium falciparum was determined in patients seeking medical care primarily for non-febrile conditions in six departments in Haiti using a newly designed qRT-PCR-based assay. METHODS: Three different methods of parasite detection were compared to assess their utility in approximating the prevalence of P. falciparum infections in the population: malaria rapid diagnostic test (RDT) designed to detect histidine-rich protein 2 (HRP2), thick smear microscopy, and a quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay based upon the small sub-unit ribosomal RNA. The limit of detection of the qRT-PCR assay utilized was 0.0003 parasite/µL of blood. Venous blood was obtained from a total of 563 subjects from six departments in Haiti, all of whom were seeking medical attention without complaints consistent with malaria. Each subject was questioned for knowledge and behaviour using demographic and epidemiological survey to identify risk factors for disease transmission. RESULTS: Among the 563 samples tested, ten and 16 were found positive for malaria by RDT and microscopy, respectively. Using the qRT-PCR test to assess the infection status of these subjects, an additional 92 were identified for a total of 108. Based upon the qRT-PCR assay results, a wide variation in prevalence of infection in asymptomatic subjects was seen between geographic locations ranging from 4-41%. The prevalence of infection was highest in the Grand Anse, Nord and Sud-Est Departments, and demographic data from questionnaires provide evidence for focal disease transmission. CONCLUSIONS: The qRT-PCR assay is sufficiently sensitive to identify an unexpectedly large number of asymptomatic, submicroscopic infections. Identifying and clearing these infections presents a significant challenge to both control and elimination efforts, but the qRT-PCR assay offers a reliable method to identify them.
Assuntos
Infecções Assintomáticas/epidemiologia , Testes Diagnósticos de Rotina/métodos , Malária Falciparum/diagnóstico , Malária Falciparum/epidemiologia , Plasmodium falciparum/isolamento & purificação , Adulto , Estudos Transversais , Feminino , Haiti/epidemiologia , Humanos , Imunoensaio , Microscopia , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , População Rural , Adulto JovemRESUMO
Haiti and the Dominican Republic, which share the island of Hispaniola, are the last locations in the Caribbean where malaria still persists. Malaria is an important public health concern in Haiti with 17,094 reported cases in 2014. Further, on January 12, 2010, a record earthquake devastated densely populated areas in Haiti including many healthcare and laboratory facilities. Weakened infrastructure provided fertile reservoirs for uncontrolled transmission of infectious pathogens. This situation results in unique challenges for malaria epidemiology and elimination efforts. To help Haiti achieve its malaria elimination goals by year 2020, the Laboratoire National de Santé Publique and Henry Ford Health System, in close collaboration with the Direction d'Épidémiologie, de Laboratoire et de Recherches and the Programme National de Contrôle de la Malaria, hosted a scientific meeting on "Elimination Strategies for Malaria in Haiti" on January 29-30, 2015 at the National Laboratory in Port-au-Prince, Haiti. The meeting brought together laboratory personnel, researchers, clinicians, academics, public health professionals, and other stakeholders to discuss main stakes and perspectives on malaria elimination. Several themes and recommendations emerged during discussions at this meeting. First, more information and research on malaria transmission in Haiti are needed including information from active surveillance of cases and vectors. Second, many healthcare personnel need additional training and critical resources on how to properly identify malaria cases so as to improve accurate and timely case reporting. Third, it is necessary to continue studies genotyping strains of Plasmodium falciparum in different sites with active transmission to evaluate for drug resistance and impacts on health. Fourth, elimination strategies outlined in this report will continue to incorporate use of primaquine in addition to chloroquine and active surveillance of cases. Elimination of malaria in Haiti will require collaborative multidisciplinary approaches, sound strategic planning, and strong ownership of strategies by the Haiti Ministère de la Santé Publique et de la Population.