BackgroundA massive cholera epidemic struck Haiti on October 2010. As part of the national choler... more BackgroundA massive cholera epidemic struck Haiti on October 2010. As part of the national cholera elimination plan, the Haitian government, UNICEF and other international partners launched a nationwide alert-response strategy from July 2013. This strategy established a coordinated methodology to rapidly target cholera-affected communities with WaSH (water sanitation and hygiene) response interventions conducted by field mobile teams. An innovative red-orange-green alert system was established, based on routine surveillance data, to weekly monitor the epidemic.Methodology/Principal findingsWe used cholera consolidated surveillance databases, alert records and details of 31,306 response interventions notified by WaSH mobile teams to describe and assess the implementation of this approach between July 2013 and June 2017. Response to red and orange alerts was heterogeneous across the country, but significantly improved throughout the study period so that 75% of red and orange alerts we...
Strengths and limitations of the study ► This is the first study assessing the prevalence of Chla... more Strengths and limitations of the study ► This is the first study assessing the prevalence of Chlamydia trachomatis (CT) and Neisseria Gonorrhoeae in key populations in Haiti. ► The lower prevalence of CT among people living with HIV underlined the importance to presumptively test and treat for sexually transmitted infection (STI), regardless of HIV status. ► Periodic risk assessment and testing, with algorithms tailored for MSM should be part of the upcoming guidelines on STI management in Haiti. ► Fear of discrimination and stigmatisation might be a limited factor to reliable answers to the questionnaire beside our best efforts to provide a judgementfree environment for our study.
We evaluated the use of matrix-assisted laser desorption ionization-time of flight mass spectrome... more We evaluated the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MS) for the identification of Vibrio cholerae. MS identified all 42 isolates of V. cholerae O1 and O139 and 7 of 9 non-O1/O139 isolates. MS correctly discriminated between all Aeromonas and V. cholerae isolates. Overall, MS performed as well as or better than biochemical methods.
Background-Hepatitis B vaccine administered shortly after birth is highly effective in preventing... more Background-Hepatitis B vaccine administered shortly after birth is highly effective in preventing mother to child transmission (MTCT) of infection. While hepatitis B vaccine was introduced in Haiti as part of a combined pentavalent vaccine in 2012, a birth dose is not yet included in the immunization schedule. Objectives-Determine the seroprevalence of hepatitis B virus (HBV) infection among pregnant women to evaluate the risk of MTCT.
We obtained 78 human blood samples from areas in Haiti with high transmission of malaria and foun... more We obtained 78 human blood samples from areas in Haiti with high transmission of malaria and found no drug resistance-associated mutations in Plasmodium falciparum chloroquine resistance transporter and Kelch 13 genes. We recommend maintaining chloroquine as the first-line drug for malaria in Haiti. Artemisinin-based therapy can be used as alternative therapy. H aiti is a unique country in the Americas because malaria is caused there mainly by Plasmodium falciparum. Despite chloroquine being used for treatment of malaria since 1955, P. falciparum is generally still susceptible to this drug (1). Thus, chloroquine, plus a single dose of the gametocytocidal drug primaquine, is still the first-line treatment for uncomplicated malaria in Haiti, as indicated by the ministry of health. This regimen began to be challenged 9 years ago after a study reported chloroquine-resistant
The impact of phage predation on bacterial pathogens in the context of human disease is not curre... more The impact of phage predation on bacterial pathogens in the context of human disease is not currently appreciated. Here, we show that predatory interactions of a phage with an important environmentally transmitted pathogen, Vibrio cholerae, can modulate the evolutionary trajectory of this pathogen during the natural course of infection within individual patients. We analyzed geographically and temporally disparate cholera patient stool samples from Haiti and Bangladesh and found that phage predation can drive the genomic diversity of intra-patient V. cholerae populations. Intra-patient phage-sensitive and phage-resistant isolates were isogenic except for mutations conferring phage resistance, and moreover, phage-resistant V. cholerae populations were composed of a heterogeneous mix of many unique mutants. We also observed that phage predation can significantly alter the virulence potential of V. cholerae shed from cholera patients. We provide the first molecular evidence for predatory phage shaping microbial community structure during the natural course of infection in humans.
Background: Rotavirus vaccines are effective in preventing severe rotavirus. Haiti introduced 2-d... more Background: Rotavirus vaccines are effective in preventing severe rotavirus. Haiti introduced 2-dose monovalent (G1P[8]) rotavirus vaccine recommended for infants at 6 and 10 weeks of age in 2014. We calculated the effectiveness of rotavirus vaccine against hospitalization for acute gastroenteritis in Haiti. Methods: We enrolled children 6-59 months old admitted May 2014-September 2019 for acute watery diarrhea any sentinel surveillance hospital. Stool was tested for rotavirus using enzyme immunoassay (EIA) and genotyped with multiplex one-step RT-PCR assay and Sanger sequencing for stratification by genotype. We used a case-negative design where cases were children positive for rotavirus and controls were negative for rotavirus. Only children eligible for vaccination were included and a child was considered vaccinated if vaccine was given ≥14 days before enrollment. We used unconditional logistic regression to calculate odds ratios and calculated 2-dose and 1-dose vaccine effectiveness (VE) as (1 − odds ratio) * 100. Results: We included 129 (19%) positive cases and 543 (81%) negative controls. Among cases, 77 (60%) were positive for equine-like G3P[8]. Two doses of rotavirus vaccine were 66% (95%
Bulletin De La Societe De Pathologie Exotique, Feb 28, 2018
Haiti, like most limited-resources countries in the world, faces numerous neglected infectious di... more Haiti, like most limited-resources countries in the world, faces numerous neglected infectious diseases. They represent a real public health issue with lethal consequences especially in children. We are reviewing here the available literature on four neglected infectious diseases, mansonelliasis, tungiasis, leprosy and anthrax. Filariasis, due to Mansonella ozzardi, has been totally neglected since its discovery in 1920 in Haiti; it persists in coastal homes with a high prevalence in adults when an effective treatment is available. The skin lesions caused by Tunga penetrans have existed since the pre-Columbian period in Haiti. They persist in the most retreated and hard-to-reach areas where the population lives in precarious conditions and in extreme poverty. New available research data show the importance of the problem with very high prevalence rates in some rural communities far away from any healthcare center. Cases of leprosy are recently reemerging as no monitoring program has been in place since 2004. Finally, anthrax is still endemic; small epidemics resurfacing periodically in families in rural areas. Screening of people for these diseases and managing the cases are necessary to improve health and reduce morbidity and mortality in Haiti.
Background Haiti’s first COVID-19 cases were confirmed on March 18, 2020, and subsequently spread... more Background Haiti’s first COVID-19 cases were confirmed on March 18, 2020, and subsequently spread throughout the country. The objective of this study was to describe clinical manifestations of COVID-19 in Haitian outpatients and to identify risk factors for severity of clinical manifestations. Methods We conducted a retrospective study of COVID-19 outpatients diagnosed from March 18-August 4, 2020, using demographic, epidemiological, and clinical data reported to the Ministry of Health (MoH). We used univariate and multivariate analysis, including multivariable logistic regression, to explore the risk factors and specific symptoms related to persons with symptomatic COVID-19 and the severity of symptomatic COVID-19 disease. Results Of 5,389 cases reported to MOH during the study period, 1,754 (32.5%) were asymptomatic. Amongst symptomatic persons 2,747 (75.6%) had mild COVID-19 and 888 (24.4%) had moderate-to-severe disease; the most common symptoms were fever (69.6%), cough (51.9%)...
Serological data can provide estimates of human exposure to both malaria vector and parasite base... more Serological data can provide estimates of human exposure to both malaria vector and parasite based on antibody responses. A multiplex bead-based assay was developed to simultaneously detect IgG to Anopheles albimanus salivary gland extract (SGE) and 23 Plasmodium falciparum antigens among 4185 participants enrolled in Artibonite department, Haiti in 2017. Logistic regression adjusted for participant- and site-level covariates and found children under 5 years and 6–15 years old had 3.7- and 5.4-fold increase in odds, respectively, of high anti-SGE IgG compared to participants >15 years. Seropositivity to P. falciparum CSP, Rh2_2030, and SEA-1 antigens was significantly associated with high IgG response against SGE, and participant enrolment at elevations under 200 m was associated with higher anti-SGE IgG levels. The ability to approximate population exposure to malaria vectors through SGE serology data is very dependent by age categories, and SGE antigens can be easily integrated...
Background An effective laboratory system is an essential component of a public health system car... more Background An effective laboratory system is an essential component of a public health system caring for patients with communicable and non-communicable diseases. Unfortunately, in developing countries this system is often sub-optimal, which negatively impacts health care. This paper describes the current situation of the clinical laboratory sector in Haiti and highlights challenges that exist in Haiti and other developing countries as they try to establish a clinical laboratory system. Method A cross-sectional survey was conducted in 30 laboratories across Haiti from January 19 to February 4, 2016. The laboratories surveyed were public or mixed public-private sector facilities belonging to different levels of the healthcare hierarchy. Labs were visited and directors of the health care institutions, lab managers, and members of their teams were interviewed and National Public Health Laboratory documents and information about the legal framework of the laboratory system was reviewed....
Historical data suggest that millions of P. falciparum parasite lineages were introduced into the... more 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 int...
Accurate malaria diagnosis is foundational for control and elimination, and Haiti relies on HRP2-... more Accurate malaria diagnosis is foundational for control and elimination, and Haiti relies on HRP2-based rapid diagnostic tests (RDTs) identifying Plasmodium falciparum in clinical and community settings. In 2017, one household and two easy-access group (EAG) surveys tested all participants (N=32,506) by conventional and high-sensitivity RDTs (cRDT/hsRDT). A subset of blood samples (n=1,154) were laboratory tested for HRP2 by bead-based immunoassay and for P. falciparum 18S rDNA by PET-PCR. Both RDT types detected low concentrations of HRP2 with sensitivity estimates between 2.6 and 14.6 ng/mL. Compared to the predicate HRP2 laboratory assay,, RDT sensitivity ranged from 86.3% to 96.0% between tests and settings, and specificity from 90.0% to 99.6%. In the household survey, the hsRDT provided a significantly higher number of positive tests, but this represented a very small proportion (<0.2%) of all participants. These data show an hsRDT may have limited utility in a malaria elimin...
Background Global estimates for cholera annually approximate 4 million cases worldwide with 95,00... more Background Global estimates for cholera annually approximate 4 million cases worldwide with 95,000 deaths. Recent outbreaks, including Haiti and Yemen, are reminders that cholera is still a global health concern. Cholera outbreaks can rapidly induce high death tolls by overwhelming the capacity of health facilities, especially in remote areas or areas of civil unrest. Recent studies demonstrated that stool specimens preserved on filter paper facilitate molecular analysis of Vibrio cholerae in resource limited settings. Specimens preserved in a rapid, low-cost, safe and sustainable manner for sequencing provides previously unavailable data about circulating cholera strains. This may ultimately contribute new information to shape public policy response on cholera control and elimination.
20 e journées nationales d'infectiologie / Médecine et maladies infectieuses 49 (2019) S110-S117 ... more 20 e journées nationales d'infectiologie / Médecine et maladies infectieuses 49 (2019) S110-S117 S113 Conclusion Ces résultats concordent avec les expériences publiées de centres pluridisciplinaires. Les liens établis avec les MT facilitent le diagnostic de BL et le parcours de soins. Le nombre de diagnostics différentiels ou associés confirment la complexité du diagnostic de BL sans omettre d'autres diagnostics. Une prise en charge pluridisciplinaire permet un diagnostic plus précis et une prise en charge personnalisée des patients. Déclaration de liens d'intérêts Les auteurs déclarent ne pas avoir de liens d'intérêts.
Background: In October 2010, cholera importation in Haiti triggered an epidemic that rapidly prov... more Background: In October 2010, cholera importation in Haiti triggered an epidemic that rapidly proved to be the world's largest epidemic of the seventh cholera pandemic. To establish effective control and elimination policies, strategies rely on the analysis of cholera dynamics. In this report, we describe the spatio-temporal dynamics of cholera and the associated environmental factors. Methodology/Principal findings: Cholera-associated morbidity and mortality data were prospectively collected at the commune level according to the World Health Organization standard definition. Attack and mortality rates were estimated and mapped to assess epidemic clusters and trends. The relationships between environmental factors were assessed at the commune level using multivariate analysis. The global attack and mortality rates were 488.9 cases/10,000 inhabitants and 6.24 deaths/10,000 inhabitants, respectively. Attack rates displayed a significantly high level of spatial heterogeneity (varying from 64.7 to 3070.9 per 10,000 inhabitants), thereby suggesting disparate outbreak processes. The epidemic course exhibited two principal outbreaks. The first outbreak (October 16, 2010-January 30, 2011) displayed a centrifugal spread of a damping wave that suddenly emerged from Mirebalais. The second outbreak began at the end of May 2011, concomitant with the onset of the rainy season, and displayed a highly fragmented epidemic pattern. Environmental factors (river and rice fields: p,0.003) played a role in disease dynamics exclusively during the early phases of the epidemic. Conclusion: Our findings demonstrate that the epidemic is still evolving, with a changing transmission pattern as time passes. Such an evolution could have hardly been anticipated, especially in a country struck by cholera for the first time. These results argue for the need for control measures involving intense efforts in rapid and exhaustive case tracking.
We investigated the antimicrobial susceptibility of 50 environmental isolates of Vibrio cholerae ... more We investigated the antimicrobial susceptibility of 50 environmental isolates of Vibrio cholerae non-O1/non-O139 collected in surface waters in Haiti in July 2012, during an active cholera outbreak. A panel of 16 antibiotics was tested on the isolates using the disk diffusion method and PCR detection of seven resistance-associated genes (strA/B, sul1/2, ermA/B, and mefA). All isolates were susceptible to amoxicillin-clavulanic acid, cefotaxime, imipenem, ciprofloxacin, norfloxacin, amikacin, and gentamicin. Nearly a quarter (22.0%) of the isolates were susceptible to all 16 antimicrobials tested and only 8.0% of the isolates (n = 4) were multidrug-resistant. The highest proportions of resistant isolates were observed for sulfonamide (70.0%), amoxicillin (12.0%), and trimethoprim-sulfamethoxazole (10.0%). One strain was resistant to erythromycin and one to doxycycline, two antibiotics used to treat cholera in Haiti. Among the 50 isolates, 78% possessed at least two resistance-associated genes, and the genes sul1, ermA, and strB were detected in all four multidrug-resistant isolates. Our results clearly indicate that the autochthonous population of V. cholerae non-O1/non-O139 found in surface waters in Haiti shows antimicrobial patterns different from that of the outbreak strain. The presence in the Haitian aquatic environment of V. cholerae non-O1/non-O139 with reduced susceptibility or resistance to antibiotics used in human medicine may constitute a mild public health threat.
BackgroundA massive cholera epidemic struck Haiti on October 2010. As part of the national choler... more BackgroundA massive cholera epidemic struck Haiti on October 2010. As part of the national cholera elimination plan, the Haitian government, UNICEF and other international partners launched a nationwide alert-response strategy from July 2013. This strategy established a coordinated methodology to rapidly target cholera-affected communities with WaSH (water sanitation and hygiene) response interventions conducted by field mobile teams. An innovative red-orange-green alert system was established, based on routine surveillance data, to weekly monitor the epidemic.Methodology/Principal findingsWe used cholera consolidated surveillance databases, alert records and details of 31,306 response interventions notified by WaSH mobile teams to describe and assess the implementation of this approach between July 2013 and June 2017. Response to red and orange alerts was heterogeneous across the country, but significantly improved throughout the study period so that 75% of red and orange alerts we...
Strengths and limitations of the study ► This is the first study assessing the prevalence of Chla... more Strengths and limitations of the study ► This is the first study assessing the prevalence of Chlamydia trachomatis (CT) and Neisseria Gonorrhoeae in key populations in Haiti. ► The lower prevalence of CT among people living with HIV underlined the importance to presumptively test and treat for sexually transmitted infection (STI), regardless of HIV status. ► Periodic risk assessment and testing, with algorithms tailored for MSM should be part of the upcoming guidelines on STI management in Haiti. ► Fear of discrimination and stigmatisation might be a limited factor to reliable answers to the questionnaire beside our best efforts to provide a judgementfree environment for our study.
We evaluated the use of matrix-assisted laser desorption ionization-time of flight mass spectrome... more We evaluated the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MS) for the identification of Vibrio cholerae. MS identified all 42 isolates of V. cholerae O1 and O139 and 7 of 9 non-O1/O139 isolates. MS correctly discriminated between all Aeromonas and V. cholerae isolates. Overall, MS performed as well as or better than biochemical methods.
Background-Hepatitis B vaccine administered shortly after birth is highly effective in preventing... more Background-Hepatitis B vaccine administered shortly after birth is highly effective in preventing mother to child transmission (MTCT) of infection. While hepatitis B vaccine was introduced in Haiti as part of a combined pentavalent vaccine in 2012, a birth dose is not yet included in the immunization schedule. Objectives-Determine the seroprevalence of hepatitis B virus (HBV) infection among pregnant women to evaluate the risk of MTCT.
We obtained 78 human blood samples from areas in Haiti with high transmission of malaria and foun... more We obtained 78 human blood samples from areas in Haiti with high transmission of malaria and found no drug resistance-associated mutations in Plasmodium falciparum chloroquine resistance transporter and Kelch 13 genes. We recommend maintaining chloroquine as the first-line drug for malaria in Haiti. Artemisinin-based therapy can be used as alternative therapy. H aiti is a unique country in the Americas because malaria is caused there mainly by Plasmodium falciparum. Despite chloroquine being used for treatment of malaria since 1955, P. falciparum is generally still susceptible to this drug (1). Thus, chloroquine, plus a single dose of the gametocytocidal drug primaquine, is still the first-line treatment for uncomplicated malaria in Haiti, as indicated by the ministry of health. This regimen began to be challenged 9 years ago after a study reported chloroquine-resistant
The impact of phage predation on bacterial pathogens in the context of human disease is not curre... more The impact of phage predation on bacterial pathogens in the context of human disease is not currently appreciated. Here, we show that predatory interactions of a phage with an important environmentally transmitted pathogen, Vibrio cholerae, can modulate the evolutionary trajectory of this pathogen during the natural course of infection within individual patients. We analyzed geographically and temporally disparate cholera patient stool samples from Haiti and Bangladesh and found that phage predation can drive the genomic diversity of intra-patient V. cholerae populations. Intra-patient phage-sensitive and phage-resistant isolates were isogenic except for mutations conferring phage resistance, and moreover, phage-resistant V. cholerae populations were composed of a heterogeneous mix of many unique mutants. We also observed that phage predation can significantly alter the virulence potential of V. cholerae shed from cholera patients. We provide the first molecular evidence for predatory phage shaping microbial community structure during the natural course of infection in humans.
Background: Rotavirus vaccines are effective in preventing severe rotavirus. Haiti introduced 2-d... more Background: Rotavirus vaccines are effective in preventing severe rotavirus. Haiti introduced 2-dose monovalent (G1P[8]) rotavirus vaccine recommended for infants at 6 and 10 weeks of age in 2014. We calculated the effectiveness of rotavirus vaccine against hospitalization for acute gastroenteritis in Haiti. Methods: We enrolled children 6-59 months old admitted May 2014-September 2019 for acute watery diarrhea any sentinel surveillance hospital. Stool was tested for rotavirus using enzyme immunoassay (EIA) and genotyped with multiplex one-step RT-PCR assay and Sanger sequencing for stratification by genotype. We used a case-negative design where cases were children positive for rotavirus and controls were negative for rotavirus. Only children eligible for vaccination were included and a child was considered vaccinated if vaccine was given ≥14 days before enrollment. We used unconditional logistic regression to calculate odds ratios and calculated 2-dose and 1-dose vaccine effectiveness (VE) as (1 − odds ratio) * 100. Results: We included 129 (19%) positive cases and 543 (81%) negative controls. Among cases, 77 (60%) were positive for equine-like G3P[8]. Two doses of rotavirus vaccine were 66% (95%
Bulletin De La Societe De Pathologie Exotique, Feb 28, 2018
Haiti, like most limited-resources countries in the world, faces numerous neglected infectious di... more Haiti, like most limited-resources countries in the world, faces numerous neglected infectious diseases. They represent a real public health issue with lethal consequences especially in children. We are reviewing here the available literature on four neglected infectious diseases, mansonelliasis, tungiasis, leprosy and anthrax. Filariasis, due to Mansonella ozzardi, has been totally neglected since its discovery in 1920 in Haiti; it persists in coastal homes with a high prevalence in adults when an effective treatment is available. The skin lesions caused by Tunga penetrans have existed since the pre-Columbian period in Haiti. They persist in the most retreated and hard-to-reach areas where the population lives in precarious conditions and in extreme poverty. New available research data show the importance of the problem with very high prevalence rates in some rural communities far away from any healthcare center. Cases of leprosy are recently reemerging as no monitoring program has been in place since 2004. Finally, anthrax is still endemic; small epidemics resurfacing periodically in families in rural areas. Screening of people for these diseases and managing the cases are necessary to improve health and reduce morbidity and mortality in Haiti.
Background Haiti’s first COVID-19 cases were confirmed on March 18, 2020, and subsequently spread... more Background Haiti’s first COVID-19 cases were confirmed on March 18, 2020, and subsequently spread throughout the country. The objective of this study was to describe clinical manifestations of COVID-19 in Haitian outpatients and to identify risk factors for severity of clinical manifestations. Methods We conducted a retrospective study of COVID-19 outpatients diagnosed from March 18-August 4, 2020, using demographic, epidemiological, and clinical data reported to the Ministry of Health (MoH). We used univariate and multivariate analysis, including multivariable logistic regression, to explore the risk factors and specific symptoms related to persons with symptomatic COVID-19 and the severity of symptomatic COVID-19 disease. Results Of 5,389 cases reported to MOH during the study period, 1,754 (32.5%) were asymptomatic. Amongst symptomatic persons 2,747 (75.6%) had mild COVID-19 and 888 (24.4%) had moderate-to-severe disease; the most common symptoms were fever (69.6%), cough (51.9%)...
Serological data can provide estimates of human exposure to both malaria vector and parasite base... more Serological data can provide estimates of human exposure to both malaria vector and parasite based on antibody responses. A multiplex bead-based assay was developed to simultaneously detect IgG to Anopheles albimanus salivary gland extract (SGE) and 23 Plasmodium falciparum antigens among 4185 participants enrolled in Artibonite department, Haiti in 2017. Logistic regression adjusted for participant- and site-level covariates and found children under 5 years and 6–15 years old had 3.7- and 5.4-fold increase in odds, respectively, of high anti-SGE IgG compared to participants >15 years. Seropositivity to P. falciparum CSP, Rh2_2030, and SEA-1 antigens was significantly associated with high IgG response against SGE, and participant enrolment at elevations under 200 m was associated with higher anti-SGE IgG levels. The ability to approximate population exposure to malaria vectors through SGE serology data is very dependent by age categories, and SGE antigens can be easily integrated...
Background An effective laboratory system is an essential component of a public health system car... more Background An effective laboratory system is an essential component of a public health system caring for patients with communicable and non-communicable diseases. Unfortunately, in developing countries this system is often sub-optimal, which negatively impacts health care. This paper describes the current situation of the clinical laboratory sector in Haiti and highlights challenges that exist in Haiti and other developing countries as they try to establish a clinical laboratory system. Method A cross-sectional survey was conducted in 30 laboratories across Haiti from January 19 to February 4, 2016. The laboratories surveyed were public or mixed public-private sector facilities belonging to different levels of the healthcare hierarchy. Labs were visited and directors of the health care institutions, lab managers, and members of their teams were interviewed and National Public Health Laboratory documents and information about the legal framework of the laboratory system was reviewed....
Historical data suggest that millions of P. falciparum parasite lineages were introduced into the... more 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 int...
Accurate malaria diagnosis is foundational for control and elimination, and Haiti relies on HRP2-... more Accurate malaria diagnosis is foundational for control and elimination, and Haiti relies on HRP2-based rapid diagnostic tests (RDTs) identifying Plasmodium falciparum in clinical and community settings. In 2017, one household and two easy-access group (EAG) surveys tested all participants (N=32,506) by conventional and high-sensitivity RDTs (cRDT/hsRDT). A subset of blood samples (n=1,154) were laboratory tested for HRP2 by bead-based immunoassay and for P. falciparum 18S rDNA by PET-PCR. Both RDT types detected low concentrations of HRP2 with sensitivity estimates between 2.6 and 14.6 ng/mL. Compared to the predicate HRP2 laboratory assay,, RDT sensitivity ranged from 86.3% to 96.0% between tests and settings, and specificity from 90.0% to 99.6%. In the household survey, the hsRDT provided a significantly higher number of positive tests, but this represented a very small proportion (<0.2%) of all participants. These data show an hsRDT may have limited utility in a malaria elimin...
Background Global estimates for cholera annually approximate 4 million cases worldwide with 95,00... more Background Global estimates for cholera annually approximate 4 million cases worldwide with 95,000 deaths. Recent outbreaks, including Haiti and Yemen, are reminders that cholera is still a global health concern. Cholera outbreaks can rapidly induce high death tolls by overwhelming the capacity of health facilities, especially in remote areas or areas of civil unrest. Recent studies demonstrated that stool specimens preserved on filter paper facilitate molecular analysis of Vibrio cholerae in resource limited settings. Specimens preserved in a rapid, low-cost, safe and sustainable manner for sequencing provides previously unavailable data about circulating cholera strains. This may ultimately contribute new information to shape public policy response on cholera control and elimination.
20 e journées nationales d'infectiologie / Médecine et maladies infectieuses 49 (2019) S110-S117 ... more 20 e journées nationales d'infectiologie / Médecine et maladies infectieuses 49 (2019) S110-S117 S113 Conclusion Ces résultats concordent avec les expériences publiées de centres pluridisciplinaires. Les liens établis avec les MT facilitent le diagnostic de BL et le parcours de soins. Le nombre de diagnostics différentiels ou associés confirment la complexité du diagnostic de BL sans omettre d'autres diagnostics. Une prise en charge pluridisciplinaire permet un diagnostic plus précis et une prise en charge personnalisée des patients. Déclaration de liens d'intérêts Les auteurs déclarent ne pas avoir de liens d'intérêts.
Background: In October 2010, cholera importation in Haiti triggered an epidemic that rapidly prov... more Background: In October 2010, cholera importation in Haiti triggered an epidemic that rapidly proved to be the world's largest epidemic of the seventh cholera pandemic. To establish effective control and elimination policies, strategies rely on the analysis of cholera dynamics. In this report, we describe the spatio-temporal dynamics of cholera and the associated environmental factors. Methodology/Principal findings: Cholera-associated morbidity and mortality data were prospectively collected at the commune level according to the World Health Organization standard definition. Attack and mortality rates were estimated and mapped to assess epidemic clusters and trends. The relationships between environmental factors were assessed at the commune level using multivariate analysis. The global attack and mortality rates were 488.9 cases/10,000 inhabitants and 6.24 deaths/10,000 inhabitants, respectively. Attack rates displayed a significantly high level of spatial heterogeneity (varying from 64.7 to 3070.9 per 10,000 inhabitants), thereby suggesting disparate outbreak processes. The epidemic course exhibited two principal outbreaks. The first outbreak (October 16, 2010-January 30, 2011) displayed a centrifugal spread of a damping wave that suddenly emerged from Mirebalais. The second outbreak began at the end of May 2011, concomitant with the onset of the rainy season, and displayed a highly fragmented epidemic pattern. Environmental factors (river and rice fields: p,0.003) played a role in disease dynamics exclusively during the early phases of the epidemic. Conclusion: Our findings demonstrate that the epidemic is still evolving, with a changing transmission pattern as time passes. Such an evolution could have hardly been anticipated, especially in a country struck by cholera for the first time. These results argue for the need for control measures involving intense efforts in rapid and exhaustive case tracking.
We investigated the antimicrobial susceptibility of 50 environmental isolates of Vibrio cholerae ... more We investigated the antimicrobial susceptibility of 50 environmental isolates of Vibrio cholerae non-O1/non-O139 collected in surface waters in Haiti in July 2012, during an active cholera outbreak. A panel of 16 antibiotics was tested on the isolates using the disk diffusion method and PCR detection of seven resistance-associated genes (strA/B, sul1/2, ermA/B, and mefA). All isolates were susceptible to amoxicillin-clavulanic acid, cefotaxime, imipenem, ciprofloxacin, norfloxacin, amikacin, and gentamicin. Nearly a quarter (22.0%) of the isolates were susceptible to all 16 antimicrobials tested and only 8.0% of the isolates (n = 4) were multidrug-resistant. The highest proportions of resistant isolates were observed for sulfonamide (70.0%), amoxicillin (12.0%), and trimethoprim-sulfamethoxazole (10.0%). One strain was resistant to erythromycin and one to doxycycline, two antibiotics used to treat cholera in Haiti. Among the 50 isolates, 78% possessed at least two resistance-associated genes, and the genes sul1, ermA, and strB were detected in all four multidrug-resistant isolates. Our results clearly indicate that the autochthonous population of V. cholerae non-O1/non-O139 found in surface waters in Haiti shows antimicrobial patterns different from that of the outbreak strain. The presence in the Haitian aquatic environment of V. cholerae non-O1/non-O139 with reduced susceptibility or resistance to antibiotics used in human medicine may constitute a mild public health threat.
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Papers by Jacques Boncy