Cholera Outbreak - Haiti, September 2022-January 2023.

On September 30, 2022, after >3 years with no confirmed cholera cases (1), the Directorate of Epidemiology, Laboratories and Research (DELR) of the Haitian Ministry of Public Health and Population (Ministère de la Santé Publique et de la Population [MSPP]) was notified of two patients with acute, watery diarrhea in the metropolitan area of Port-au-Prince. Within 2 days, Haiti's National Public Health Laboratory confirmed the bacterium Vibrio cholerae O1 in specimens from the two patients with suspected cholera infection, and an outbreak investigation began immediately. As of January 3, 2023, >20,000 suspected cholera cases had been reported throughout the country, and 79% of patients have been hospitalized. The moving 14-day case fatality ratio (CFR) was 3.0%. Cholera, which is transmitted through ingestion of water or food contaminated with fecal matter, can cause acute, severe, watery diarrhea that can rapidly lead to dehydration, shock, and death if not treated promptly (2). Haiti is currently facing ongoing worsening of gang violence, population displacement, social unrest, and insecurity, particularly in the metropolitan area of Port-au-Prince, including Belair, Bas-Delmas, Centre-Ville, Martissant, Cité Soleil, Croix-des Bouquets, and Tabarre, creating an environment that has facilitated the current resurgence of cholera (3). This report describes the initial investigation, ongoing outbreak, and public health response to cholera in Haiti. Cholera outbreak responses require a multipronged, multisectoral approach including surveillance; case management; access to safe water, sanitation, and hygiene (WASH) services; targeted oral cholera vaccine (OCV) campaigns; risk communication; and community engagement. This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy.

Leveraging PEPFAR-Supported Health Information Systems for COVID-19 Pandemic Response.

Since 2003, the US President's Emergency Plan for AIDS Relief (PEPFAR) has supported implementation and maintenance of health information systems for HIV/AIDS and related diseases, such as tuberculosis, in numerous countries. As the COVID-19 pandemic emerged, several countries conducted rapid assessments and enhanced existing PEPFAR-funded HIV and national health information systems to support COVID-19 surveillance data collection, analysis, visualization, and reporting needs. We describe efforts at the US Centers for Disease Control and Prevention (CDC) headquarters in Atlanta, Georgia, USA, and CDC country offices that enhanced existing health information systems in support COVID-19 pandemic response. We describe CDC activities in Haiti as an illustration of efforts in PEPFAR countries. We also describe how investments used to establish and maintain standards-based health information systems in resource-constrained settings can have positive effects on health systems beyond their original scope.

Nasopharyngeal Carriage of Streptococcus pneumoniae Among Young Children in Haiti Before Pneumococcal Conjugate Vaccine Introduction.

BACKGROUND: Streptococcus pneumoniae, or pneumococcus, is a leading cause of morbidity and mortality in children worldwide. Pneumococcal conjugate vaccines (PCV) reduce carriage in the nasopharynx, preventing disease. We conducted a pneumococcal carriage study to estimate the prevalence of pneumococcal colonization, identify risk factors for colonization, and describe antimicrobial susceptibility patterns among pneumococci colonizing young children in Port-au-Prince, Haiti, before introduction of 13-valent PCV (PCV13). METHODS: We conducted a cross-sectional study of children aged 6-24 months at an immunization clinic in Port-au-Prince between September 2015 and January 2016. Consenting parents were interviewed about factors associated with pneumococcal carriage; nasopharyngeal swabs were collected from each child and cultured for pneumococcus after broth enrichment. Pneumococcal isolates were serotyped and underwent antimicrobial susceptibility testing. We compared frequency of demographic, clinical, and environmental factors among pneumococcus-colonized children (carriers) to those who were not colonized (noncarriers) using unadjusted bivariate analysis and multivariate logistic regression. RESULTS: Pneumococcus was isolated from 308 of the 685 (45.0%) children enrolled. Overall, 157 isolates (50.8%) were PCV13 vaccine-type serotypes; most common were 6A (13.3%), 19F (12.6%), 6B (9.7%), and 23F (6.1%). Vaccine-type isolates were significantly more likely to be nonsusceptible to ≥1 antimicrobial (63.1% vs 45.4%, P = .002). On bivariate analysis, carriers were significantly more likely than noncarriers to live in a household without electricity or running water, to share a bedroom with ≥3 people, to have a mother or father who did not complete secondary education, and to have respiratory symptoms in the 24 hours before enrollment (P < .05 for all comparisons). On multivariable analysis, completion of the pentavalent vaccination series (targeting diphtheria, pertussis, tetanus, hepatitis B, and Haemophilus influenzae type b) remained significantly more common among noncarriers. CONCLUSIONS: Nearly a quarter of healthy children surveyed in Haiti were colonized with vaccine-type pneumococcal serotypes. This baseline carriage study will enable estimation of vaccine impact following nationwide introduction of PCV13.

Transmission of Zika Virus - Haiti, October 12, 2015-September 10, 2016.

Zika virus disease is caused by infection with a flavivirus with broad geographic distribution and is most frequently transmitted by the bite of an infected mosquito. The disease was first identified in the World Health Organization's Region of the Americas in 2015 and was followed by a surge in reported cases of congenital microcephaly in Brazil; Zika virus disease rapidly spread to the rest of the region and the Caribbean (1), including Haiti. Infection with the virus is associated with adverse fetal outcomes (1) and rare neurologic complications in adults. The magnitude of public health issues associated with Zika virus led the World Health Organization to declare the Zika virus outbreak a Public Health Emergency of International Concern on February 1, 2016 (2). Because many persons with mild Zika virus disease are asymptomatic and might not seek care, it is difficult to estimate the actual incidence of Zika virus infection. During October 12, 2015-September 10, 2016, the Haitian Ministry of Public Health and Population (Ministère de la Santé Publique et de la Population [MSPP]) detected 3,036 suspected cases of Zika virus infection in the general population, 22 suspected cases of Zika virus disease among pregnant women, 13 suspected cases of Guillain-Barré syndrome (GBS), and 29 suspected cases of Zika-associated congenital microcephaly. Nineteen (0.6%) patients with suspected Zika virus disease, residing in Ouest (10 patients), Artibonite (six), and Centre (three) administrative departments,* have been confirmed by laboratory testing, including two among pregnant women and 17 in the general population. Ongoing laboratory-enhanced surveillance to monitor Zika virus disease in Haiti is important to understanding the outbreak and ensuring effective response activities.

Association between chlorine-treated drinking water, the gut microbiome, and enteric pathogen burden in young children in Haiti: An observational study.

OBJECTIVE: The effects of sanitation and hygiene interventions on the gut microbiome and enteric pathogen burden are not well understood. We measured the association between free chlorine residue (FCR) levels in drinking water, microbiome composition, and stool enteric pathogens in infants and young children in Haiti. METHODS: FCR levels were measured in household drinking water and enteric pathogen burden was evaluated using multiplex RT-PCR of stool among 131 children from one month to five years of age living in Mirebalais, Haiti. Microbiome profiling was performed using metagenomic sequencing. RESULTS: Most individuals lived in households with undetectable FCR measured in the drinking water (112/131, 86%). Detection of enteric pathogen DNA in stool was common and did not correlate with household water FCR. The infant microbiome in households with detectable FCR demonstrated reduced richness (fewer total number of species, P = 0.04 Kruskall-Wallis test) and less diversity by Inverse Simpson measures (P = 0.05) than households with undetectable FCR. Infants in households with a detectable FCR were more likely to have abundant Bifidobacterium. Using in vitro susceptibility testing, we found that some Bifidobacterium species were resistant to chlorine. CONCLUSIONS: FCR in household drinking water did not correlate with enteric pathogen burden in our study.

Inferring the proportion of undetected cholera infections from serological and clinical surveillance in an immunologically naive population.

Most infections with pandemic Vibrio cholerae are thought to result in subclinical disease and are not captured by surveillance. Previous estimates of the ratio of infections to clinical cases have varied widely (2 to 100). Understanding cholera epidemiology and immunity relies on the ability to translate between numbers of clinical cases and the underlying number of infections in the population. We estimated the infection incidence during the first months of an outbreak in a cholera-naive population using a Bayesian vibriocidal antibody titer decay model combining measurements from a representative serosurvey and clinical surveillance data. 3,880 suspected cases were reported in Grande Saline, Haiti, between 20 October 2010 and 6 April 2011 (clinical attack rate 18.4%). We found that more than 52.6% (95% Credible Interval (CrI) 49.4-55.7) of the population ≥2 years showed serologic evidence of infection, with a lower infection rate among children aged 2-4 years (35.5%; 95%CrI 24.2-51.6) compared with people ≥5 years (53.1%; 95%CrI 49.4-56.4). This estimated infection rate, nearly three times the clinical attack rate, with underdetection mainly seen in those ≥5 years, has likely impacted subsequent outbreak dynamics. Our findings show how seroincidence estimates improve understanding of links between cholera burden, transmission dynamics and immunity.

Investigation of Four Cases of Stevens-Johnson Syndrome among Participants in a Mass Drug Administration Campaign with Sulfadoxine-Pyrimethamine and Primaquine in Haiti, 2020.

In 2018, a mass drug administration (MDA) campaign for malaria elimination was piloted in Haiti. The pilot treated 36,338 people with sulfadoxine-pyrimethamine (SP) and primaquine; no severe adverse events were detected. In 2020, another MDA campaign using the same medications was implemented to mitigate an upsurge in malaria cases during the COVID-19 pandemic. Four cases of Stevens-Johnson syndrome (SJS) were identified among the 42,249 people who took the medications. Three of these individuals required hospitalization; all survived. In addition to SP ingestion, an investigation of potential causes for increased SJS cases identified that all four cases had human leukocyte antigens A*29 and/or B*44:03, another known risk factor for SJS. Additionally, three of the four case individuals had antibodies to SARS-CoV-2, and the fourth may have been exposed around the same time. These findings raise the possibility that recent SARS-CoV-2 infection may have contributed to the increased risk for SJS associated with SP exposure during the 2020 campaign.

Diversity of rotavirus strains circulating in Haiti before and after introduction of monovalent vaccine.

Background: Haiti introduced a monovalent human group A rotavirus (RVA) vaccine (Rotarix) into its routine infant immunization program in April 2014. The goal of the surveillance program was to characterize RVA strains circulating in Haiti before and after RVA vaccine introduction. Methods: Stool samples were collected from children <5 years old presenting with acute gastroenteritis at 16 hospitals in Haiti. RVA antigen enzyme immunoassay (EIA) testing was performed, and G and P genotypes were determined for positive specimens. In this study, genotype data for samples collected from May 2012 through April 2014 (the pre-vaccine introduction era) and May 2014 through July 2019 (post-vaccine introduction era) were analyzed. Results: A total of 809 specimens were tested by the Centers for Disease Control and Prevention. During the pre-vaccine introduction era (May 2012 through April 2014), G12P[8] was the predominant genotype, detected in 88-94% of specimens. There was a high prevalence of the equine-like G3P[8] genotype among Haitian children with RVA after vaccine introduction. Conclusions: The predominance of equine-like G3P[8] in three of five RVA seasons post-vaccine introduction suggests possible vaccine-specific selection pressure in Haiti. These temporal variations in RVA genotype predominance will require continued monitoring in Haiti as the vaccination program continues.

Epidemiology and risk factors related to severity of clinical manifestations of COVID-19 in outpatients: A retrospective study in Haiti.

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%), and myalgia (45.8%). The odds of having moderate-to-severe disease were highest among persons with hypertension (aOR = 1.72, 95% Confidence Interval [CI] (1.34, 2.20), chronic pulmonary disease (aOR = 3.93, 95% CI (1.93, 8.17)) and tuberculosis (aOR = 3.44, 95% CI (1.35, 9.14)) compared to persons without those conditions. The odds of having moderate-to-severe disease increased with age but was also seen among children aged 0-4 years (OR: 1.73, 95% CI (0.93, 3.08)), when using 30-39 years old as the reference group. All of the older age groups, 50-64 years, 65-74 years, 75-84 years, and 85+ years, had significantly higher odds of having moderate-to-severe COVID-19 compared with ages 30-39 years. Diabetes was associated with elevated odds of moderate-to-severe disease in bivariate analysis (OR = 2.17, 95% CI (1.58,2.98) but, this association did not hold in multivariable analyses (aOR = 1.22,95%CI (0.86,1.72)). CONCLUSION: These findings from a resource-constrained country highlight the importance of surveillance systems to track emerging infections and their risk factors. In addition to co-morbidities described elsewhere, tuberculosis was a risk factor for moderate-to-severe COVID-19 disease.

Effectiveness of monovalent rotavirus vaccine against hospitalizations due to all rotavirus and equine-like G3P[8] genotypes in Haiti 2014-2019.

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 at 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% CI: 44, 80) effective against hospitalizations due to any strain of rotavirus and 64% (95% CI: 33, 81) effective against hospitalizations due to the equine-like G3P[8] genotype. CONCLUSIONS: These findings are comparable to other countries in the Americas region. To the best of our knowledge, this is the first VE estimate both against the equine-like G3P[8] genotype and from a Caribbean country. Overall, these results support rotavirus vaccine use and demonstrate the importance of complete vaccination.

Impact of Monovalent Rotavirus Vaccine on Rotavirus Hospitalizations among Children Younger Than 5 Years of Age in the Ouest and Artibonite Departments, Haiti, 2013 to 2019.

Rotavirus is responsible for 26% of diarrheal deaths in Latin America and the Caribbean. Haiti introduced the monovalent rotavirus vaccine in April 2014. The objective of this analysis is to describe the impact of the rotavirus vaccine on hospitalizations among Haitian children younger than 5 years old during the first 5 years after introduction. This analysis includes all children with diarrhea who were enrolled as part of a sentinel surveillance system at two hospitals from May 2013 to April 2019. We compare the proportion of rotavirus-positive specimens in each post-vaccine introduction year to the pre-vaccine period. To account for the potential dilution of the proportion of rotavirus-positive specimens from a waning cholera outbreak, we also analyzed annual trends in the absolute number of positive stools, fit a two-component finite-mixture model to the negative specimens, and fit a negative binomial time series model to the pre-vaccine rotavirus-positive specimens to predict the number of rotavirus diarrhea hospital admissions in the absence of rotavirus vaccination. The overall percentage of rotavirus-positive specimens declined by 22% the first year after introduction, increased by 17% the second year, and declined by 33% to 50% the subsequent 3 years. All sensitivity analyses confirmed an overall decline. We observed a clear annual rotavirus seasonality before and after vaccine introduction, with the greatest activity in December through April, and a biennial pattern, with high sharp peaks and flatter longer periods of increased rotavirus activity in alternating years, consistent with suboptimal vaccination coverage. Overall, our study shows evidence that the introduction of the rotavirus vaccine reduced the burden of severe rotavirus diarrhea.

Increase in Reported Cholera Cases in Haiti Following Hurricane Matthew: An Interrupted Time Series Model.

Matthew, a category 4 hurricane, struck Haiti on October 4, 2016, causing widespread flooding and damage to buildings and crops, and resulted in many deaths. The damage caused by Matthew raised concerns of increased cholera transmission particularly in Sud and Grand'Anse departments, regions which were hit most heavily by the storm. To evaluate the change in reported cholera cases following Hurricane Matthew on reported cholera cases, we used interrupted time series regression models of daily reported cholera cases, controlling for the impact of both rainfall, following a 4-week lag, and seasonality, from 2013 through 2016. Our results indicate a significant increase in reported cholera cases after Matthew, suggesting that the storm resulted in an immediate surge in suspect cases, and a decline in reported cholera cases in the 46-day post-storm period, after controlling for rainfall and seasonality. Regression models stratified by the department indicate that the impact of the hurricane was regional, with larger surges in the two most highly storm-affected departments: Sud and Grand'Anse. These models were able to provide input to the Ministry of Health in Haiti on the national and regional impact of Hurricane Matthew and, with further development, could provide the flexibility of use in other emergency situations. This article highlights the need for continued cholera prevention and control efforts, particularly in the wake of natural disasters such as hurricanes, and the continued need for intensive cholera surveillance nationally.

Cost Evaluation of a Government-Conducted Oral Cholera Vaccination Campaign-Haiti, 2013.

The devastating 2010 cholera epidemic in Haiti prompted the government to introduce oral cholera vaccine (OCV) in two high-risk areas of Haiti. We evaluated the direct costs associated with the government's first vaccine campaign implemented in August-September 2013. We analyzed data for major cost categories and assessed the efficiency of available campaign resources to vaccinate the target population. For a target population of 107,906 persons, campaign costs totaled $624,000 and 215,295 OCV doses were dispensed. The total vaccine and operational cost was $2.90 per dose; vaccine alone cost $1.85 per dose, vaccine delivery and administration $0.70 per dose, and vaccine storage and transport $0.35 per dose. Resources were greater than needed-our analyses suggested that approximately 2.5-6 times as many persons could have been vaccinated during this campaign without increasing the resources allocated for vaccine delivery and administration. These results can inform future OCV campaigns in Haiti.

Building and Rebuilding: The National Public Health Laboratory Systems and Services Before and After the Earthquake and Cholera Epidemic, Haiti, 2009-2015.

Before the 2010 devastating earthquake and cholera outbreak, Haiti's public health laboratory systems were weak and services were limited. There was no national laboratory strategic plan and only minimal coordination across the laboratory network. Laboratory capacity was further weakened by the destruction of over 25 laboratories and testing sites at the departmental and peripheral levels and the loss of life among the laboratory health-care workers. However, since 2010, tremendous progress has been made in building stronger laboratory infrastructure and training a qualified public health laboratory workforce across the country, allowing for decentralization of access to quality-assured services. Major achievements include development and implementation of a national laboratory strategic plan with a formalized and strengthened laboratory network; introduction of automation of testing to ensure better quality of results and diversify the menu of tests to effectively respond to outbreaks; expansion of molecular testing for tuberculosis, human immunodeficiency virus, malaria, diarrheal and respiratory diseases; establishment of laboratory-based surveillance of epidemic-prone diseases; and improvement of the overall quality of testing. Nonetheless, the progress and gains made remain fragile and require the full ownership and continuous investment from the Haitian government to sustain these successes and achievements.

Strengthening National Disease Surveillance and Response-Haiti, 2010-2015.

Haiti's health system has faced many challenges over the years, with competing health priorities in the context of chronic financial and human resource limitations. As a result, the existing notifiable disease surveillance system was unable to provide the most basic epidemiologic data for public health decision-making and action. In the wake of the January 2010 earthquake, the Haitian Ministry of Public Health and Population collaborated with the U.S. Centers for Disease Control and Prevention, the Pan American Health Organization, and other local and international partners to implement a functional national surveillance system. More than 7 years later, it is important to take the opportunity to reflect on progress made on surveillance and response in Haiti, including disease detection, reporting, outbreak investigation, and response. The national epidemiologic surveillance network that started with 51 sites in 2010 has been expanded to 357 sites as of December 2015. Disease outbreaks identified via the surveillance system, or other surveillance approaches, are investigated by epidemiologists trained by the Ministry of Health's Field Epidemiology Training Program. Other related surveillance modules have been developed on the same model and electronic platform, allowing the country to document the impact of interventions, track progress, and monitor health problems. Sustainability remains the greatest challenge since most of the funding for surveillance come from external sources.

Evaluation of Knowledge and Practices Regarding Cholera, Water Treatment, Hygiene, and Sanitation Before and After an Oral Cholera Vaccination Campaign-Haiti, 2013-2014.

In 2013, the Government of Haiti implemented its first oral cholera vaccine (OCV) campaign in Petite Anse, an urban setting, and Cerca Carvajal, a rural commune. We conducted and compared responses to two independent cross-sectional knowledge and practices household surveys pre- (N = 297) and post- (N = 302) OCV campaign in Petite Anse. No significant differences in knowledge about causes, symptoms, and prevention of cholera were noted. Compared with precampaign respondents, fewer postcampaign respondents reported treating (66% versus 27%, P < 0.001) and covering (96% versus 89%, P = 0.02) their drinking water. Compared with precampaign, postcampaign survey household observations showed increased availability of soap (16.2% versus 34.5%, P = 0.001) and handwashing stations (14.7% versus 30.1%, P = 0.01), but no significant changes in handwashing practices were reported. Although there was no change in knowledge, significant decreases in water treatment practices necessary for cholera and other diarrheal diseases prevention were noted in the postcampaign survey. Future OCV campaigns in Haiti should be used as an opportunity to emphasize the importance of maintaining good water, sanitation, and hygiene practices, and include a comprehensive, integrated approach for cholera control.

Hospitalizations and Deaths Because of Respiratory and Diarrheal Diseases Among Haitian Children Under Five Years of Age, 2011-2013.

BACKGROUND: Respiratory and diarrheal diseases are leading causes of morbidity and mortality among children younger than 5 years in developing countries. Data on the burden of these diseases in Haiti are scarce. METHODS: We conducted a retrospective review of hospital admission registries during January 1, 2011-December 31, 2013 for children younger than 5 years in 6 hospitals in Haiti. We recorded the number of all-cause, respiratory and diarrheal disease admissions and deaths by epidemiologic week and age. RESULTS: A total of 31,565 hospital admissions and 1763 deaths were recorded among children aged <5 years during the study period. Respiratory diseases accounted for 9183 (29%) hospitalizations and 301 (17%) deaths. Children aged 6-23 months had the highest percentage of hospitalizations attributable to respiratory diseases (38%), whereas children aged 36-47 months had the highest proportion of deaths attributable to respiratory diseases (37%). Respiratory disease hospitalizations followed a bimodal seasonal pattern, with peaks during May-June and October-December. Diarrheal diseases accounted for 8063 (26%) hospitalizations and 224 (13%) deaths. Children aged 6-11 months had the highest percentage of diarrhea-associated hospitalizations (39%) and deaths (29%). Diarrheal disease admissions peaked in January-April before the rainy season. CONCLUSIONS: Respiratory and diarrheal diseases contributed to more than half of hospitalizations and almost a third of deaths in children younger than 5 years in Haiti. These data are essential to assess the impact of pneumococcal and rotavirus vaccines and other interventions in Haiti.

Hospitalizations and deaths caused by diarrhea in children five years old and younger at four hospitals in Haiti, 2010-2012.

Worldwide, diarrhea is a major contributor to morbidity and mortality in children; however, there are few data on the burden of diarrheal disease in Haiti. We conducted a retrospective review of hospital discharge registries from 2010 to 2012 in the pediatric wards of four Haitian hospitals and recorded the number of all-cause hospitalizations and deaths as well as diarrheal hospitalizations and deaths by age (≤ 2 and 3-5 years) and epidemiological week. Diarrhea was associated with 3,582 (33.7%) of 10,621 hospitalizations and 62 (11.5%) of 540 in-hospital deaths in children ≤ 5 years old. Of these children, 88.5% and 96.8%, respectively, were among children ≤ 2 years old. The highest proportions of diarrhea-associated hospitalizations occurred from January to April. At four Haitian hospitals over a 3-year period, during which time a major epidemic of cholera occurred, diarrheal disease in children ≤ 5 years was a major contributor to pediatric hospitalizations and mortality.

Dengue virus infections among Haitian and expatriate non-governmental organization workers--Léogane and Port-au-Prince, Haiti, 2012.

In October 2012, the Haitian Ministry of Health and the US CDC were notified of 25 recent dengue cases, confirmed by rapid diagnostic tests (RDTs), among non-governmental organization (NGO) workers. We conducted a serosurvey among NGO workers in Léogane and Port-au-Prince to determine the extent of and risk factors for dengue virus infection. Of the total 776 staff from targeted NGOs in Léogane and Port-au-Prince, 173 (22%; 52 expatriates and 121 Haitians) participated. Anti-dengue virus (DENV) IgM antibody was detected in 8 (15%) expatriates and 9 (7%) Haitians, and DENV non-structural protein 1 in one expatriate. Anti-DENV IgG antibody was detected in 162 (94%) participants (79% of expatriates; 100% of Haitians), and confirmed by microneutralization testing as DENV-specific in 17/34 (50%) expatriates and 42/42 (100%) Haitians. Of 254 pupae collected from 68 containers, 65% were Aedes aegypti; 27% were Ae. albopictus. Few NGO workers reported undertaking mosquito-avoidance action. Our findings underscore the risk of dengue in expatriate workers in Haiti and Haitians themselves.

Laboratory-confirmed cholera and rotavirus among patients with acute diarrhea in four hospitals in Haiti, 2012-2013.

An outbreak of cholera began in Haiti in October of 2010. To understand the progression of epidemic cholera in Haiti, in April of 2012, we initiated laboratory-enhanced surveillance for diarrheal disease in four Haitian hospitals in three departments. At each site, we sampled up to 10 hospitalized patients each week with acute watery diarrhea. We tested 1,616 specimens collected from April 2, 2012 to March 28, 2013; 1,030 (63.7%) specimens yielded Vibrio cholerae, 13 (0.8%) specimens yielded Shigella, 6 (0.4%) specimens yielded Salmonella, and 63 (3.9%) specimens tested positive for rotavirus. Additionally, 13.5% of children < 5 years old tested positive for rotavirus. Of 1,030 V. cholerae isolates, 1,020 (99.0%) isolates were serotype Ogawa, 9 (0.9%) isolates were serotype Inaba, and 1 isolate was non-toxigenic V. cholerae O139. During 1 year of surveillance, toxigenic cholera continued to be the main cause of acute diarrhea in hospitalized patients, and rotavirus was an important cause of diarrhea-related hospitalizations in children.