Jessica E. Teng

Use of Oral Cholera Vaccine in Haiti: A Rural Demonstration Project

A cholera epidemic has claimed the lives of more than 8,000 Haitians and sickened 650,000 since the outbreak began in October 2010. Early intervention in the epidemic focused on case-finding, treatment, and water and sanitation interventions for prevention of transmission. Use of oral cholera vaccine (OCV) as part of a complementary set of control activities was considered but initially rejected by policymakers. In December 2011, the Minister of Health of Haiti called for a demonstration of the acceptability and feasibility of the use of OCV in urban and rural Haiti. This paper describes the collaborative activity that offered OCV to one region of the Artibonite Department of rural Haiti in addition to other ongoing treatment and control measures. Despite logistics and cold chain challenges, 45,417 persons were successfully vaccinated with OCV in the region, and 90.8% of these persons completed their second dose.

Evolutionary consequences of intra-patient phage predation on microbial populations

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. DOI: http://dx.doi.org/10.7554/eLife.03497.001

Effectiveness of reactive oral cholera vaccination in rural Haiti: a case-control study and bias-indicator analysis

BACKGROUND Between April and June, 2012, a reactive cholera vaccination campaign was done in Haiti with an oral inactivated bivalent whole-cell vaccine. We aimed to assess the effectiveness of the vaccine in a case-control study and to assess the likelihood of bias in that study in a bias-indicator study. METHODS Residents of Bocozel or Grand Saline who were eligible for the vaccination campaign (ie, age ≥12 months, not pregnant, and living in the region at the time of the vaccine campaign) were included. In the primary case-control study, cases had acute watery diarrhoea, sought treatment at one of three participating cholera treatment units, and had a stool sample positive for cholera by culture. For each case, four control individuals who did not seek treatment for acute watery diarrhoea were matched by location of residence, enrolment time (within 2 weeks of the case), and age (1-4 years, 5-15 years, and >15 years). Cases in the bias-indicator study were individuals with acute watery diarrhoea with a negative stool sample for cholera. Controls were selected in the same manner as in the primary case-control study. Trained staff used standard laboratory procedures to do rapid tests and stool cultures from study cases. Participants were interviewed to collect data on sociodemographic characteristics, risk factors for cholera, and self-reported vaccination. Data were analysed by conditional logistic regression, adjusting for matching factors. FINDINGS From Oct 24, 2012, to March 9, 2014, 114 eligible individuals presented with acute watery diarrhoea and were enrolled, 25 of whom were subsequently excluded. 47 participants were analysed as cases in the vaccine effectiveness case-control study and 42 as cases in the bias-indicator study. 33 (70%) of 47 cholera cases self-reported vaccination versus 167 (89%) of 188 controls (vaccine effectiveness 63%, 95% CI 8-85). 27 (57%) of 47 cases had certified vaccination versus 147 (78%) of 188 controls (vaccine effectiveness 58%, 13-80). Neither self-reported nor verified vaccination was significantly associated with non-cholera diarrhoea (vaccine effectiveness 18%, 95% CI -208 to 78 by self-report and -21%, -238 to 57 by verified vaccination). INTERPRETATION Bivalent whole-cell oral cholera vaccine effectively protected against cholera in Haiti from 4 months to 24 months after vaccination. Vaccination is an important component of efforts to control cholera epidemics. FUNDING National Institutes of Health, Delivering Oral Vaccines Effectively project, and Department of Global Health and Social Medicine at Harvard Medical School.

Immunogenicity of a Killed Bivalent (O1 and O139) Whole Cell Oral Cholera Vaccine, Shanchol, in Haiti

Background Studies of the immunogenicity of the killed bivalent whole cell oral cholera vaccine, Shanchol, have been performed in historically cholera-endemic areas of Asia. There is a need to assess the immunogenicity of the vaccine in Haiti and other populations without historical exposure to Vibrio cholerae. Methodology/Principal Findings We measured immune responses after administration of Shanchol, in 25 adults, 51 older children (6–17 years), and 47 younger children (1–5 years) in Haiti, where cholera was introduced in 2010. A≥4-fold increase in vibriocidal antibody titer against V. cholerae O1 Ogawa was observed in 91% of adults, 74% of older children, and 73% of younger children after two doses of Shanchol; similar responses were observed against the Inaba serotype. A≥2-fold increase in serum O-antigen specific polysaccharide IgA antibody levels against V. cholerae O1 Ogawa was observed in 59% of adults, 45% of older children, and 61% of younger children; similar responses were observed against the Inaba serotype. We compared immune responses in Haitian individuals with age- and blood group-matched individuals from Bangladesh, a historically cholera-endemic area. The geometric mean vibriocidal titers after the first dose of vaccine were lower in Haitian than in Bangladeshi vaccinees. However, the mean vibriocidal titers did not differ between the two groups after the second dose of the vaccine. Conclusions/Significance A killed bivalent whole cell oral cholera vaccine, Shanchol, is highly immunogenic in Haitian adults and children. A two-dose regimen may be important in Haiti, and other populations lacking previous repeated exposures to V. cholerae.

Cholera Vaccination Campaign Contributes to Improved Knowledge Regarding Cholera and Improved Practice Relevant to Waterborne Disease in Rural Haiti

Background Haitis cholera epidemic has been devastating partly due to underlying weak infrastructure and limited clean water and sanitation. A comprehensive approach to cholera control is crucial, yet some have argued that oral cholera vaccination (OCV) might result in reduced hygiene practice among recipients. We evaluated the impact of an OCV campaign on knowledge and health practice in rural Haiti. Methodology/Principal Findings We administered baseline surveys on knowledge and practice relevant to cholera and waterborne disease to every 10th household during a census in rural Haiti in February 2012 (N = 811). An OCV campaign occurred from May–June 2012 after which we administered identical surveys to 518 households randomly chosen from the same region in September 2012. We compared responses pre- and post-OCV campaign. Post-vaccination, there was improved knowledge with significant increase in percentage of respondents with ≥3 correct responses on cholera transmission mechanisms (odds ratio[OR] 1.91; 95% confidence interval[CI] 1.52–2.40), preventive methods (OR 1.83; 95% CI 1.46–2.30), and water treatment modalities (OR 2.75; 95% CI 2.16–3.50). Relative to pre-vaccination, participants were more likely post-OCV to report always treating water (OR 1.62; 95% CI 1.28–2.05). Respondents were also more likely to report hand washing with soap and water >4 times daily post-vaccine (OR 1.30; 95% CI 1.03–1.64). Knowledge of treating water as a cholera prevention measure was associated with practice of always treating water (OR 1.47; 95% CI 1.14–1.89). Post-vaccination, knowledge was associated with frequent hand washing (OR 2.47; 95% CI 1.35–4.51). Conclusion An OCV campaign in rural Haiti was associated with significant improvement in cholera knowledge and practices related to waterborne disease. OCV can be part of comprehensive cholera control and reinforce, not detract from, other control efforts in Haiti.

A Randomized Trial of Ready-to-Use Supplementary Food Versus Corn-Soy Blend Plus as Food Rations for HIV-Infected Adults on Antiretroviral Therapy in Rural Haiti

BACKGROUND The epidemics of food insecurity, malnutrition, and human immunodeficiency virus (HIV) frequently overlap. HIV treatment programs increasingly provide nutrient-dense ready-to-use supplementary foods (RUSFs) to patients living with HIV and food insecurity, but in the absence of wasting, it is not known if RUSF confers benefit above less costly food commodities. METHODS We performed a randomized trial in rural Haiti comparing an RUSF with less costly corn-soy blend plus (CSB+) as a monthly supplement to patients with HIV infection who were on antiretroviral therapy (ART) <24 months prior to study start. We compared 6- and 12-month outcomes by ration type in terms of immunologic response, body mass index (BMI), adherence to ART, general health quality of life, household food insecurity, and household wealth. RESULTS A cohort of 524 patients with HIV receiving ART was randomized and followed over time. Median CD4 cell count at baseline was 339 cells/µL (interquartile range [IQR], 197-475 cells/µL) for the CSB+ group, and 341 cells/µL (IQR, 213-464/µL) for the RUSF group. Measured outcomes improved from baseline over time, but there were no statistically significant differences in change for BMI, household wealth index, hunger, general health perception score, or adherence to ART by ration type at 6 or 12 months. The RUSF group had higher CD4 count at 12 months, but this was also not statistically significant. CONCLUSIONS In 12 months of follow-up, there was no statistically significant difference in outcomes between those receiving RUSF-based compared with CSB+-based rations in a cohort of HIV-infected adults on ART in rural Haiti.

Using Mobile Health (mHealth) and Geospatial Mapping Technology in a Mass Campaign for Reactive Oral Cholera Vaccination in Rural Haiti

Background In mass vaccination campaigns, large volumes of data must be managed efficiently and accurately. In a reactive oral cholera vaccination (OCV) campaign in rural Haiti during an ongoing epidemic, we used a mobile health (mHealth) system to manage data on 50,000 participants in two isolated communities. Methods Data were collected using 7-inch tablets. Teams pre-registered and distributed vaccine cards with unique barcodes to vaccine-eligible residents during a census in February 2012. First stored on devices, data were uploaded nightly via Wi-fi to a web-hosted database. During the vaccination campaign between April and June 2012, residents presented their cards at vaccination posts and their barcodes were scanned. Vaccinee data from the census were pre-loaded on tablets to autopopulate the electronic form. Nightly analysis of the days community coverage informed the following days vaccination strategy. We generated case-finding reports allowing us to identify those who had not yet been vaccinated. Results During 40 days of vaccination, we collected approximately 1.9 million pieces of data. A total of 45,417 people received at least one OCV dose; of those, 90.8% were documented to have received 2 doses. Though mHealth required up-front financial investment and training, it reduced the need for paper registries and manual data entry, which would have been costly, time-consuming, and is known to increase error. Using Global Positioning System coordinates, we mapped vaccine posts, population size, and vaccine coverage to understand the reach of the campaign. The hardware and software were usable by high school-educated staff. Conclusion The use of mHealth technology in an OCV campaign in rural Haiti allowed timely creation of an electronic registry with population-level census data, and a targeted vaccination strategy in a dispersed rural population receiving a two-dose vaccine regimen. The use of mHealth should be strongly considered in mass vaccination campaigns in future initiatives.

Immunogenicity of the Bivalent Oral Cholera Vaccine Shanchol in Haitian Adults With HIV Infection

We evaluated immune responses following bivalent oral cholera vaccination (Shanchol [Shantha Biotechnics]; BivWC) in a cohort of 25 human immunodeficiency virus (HIV)-infected adults in Haiti. Compared with adults without HIV infection, vaccination in HIV-infected individuals resulted in lower vibriocidal responses against Vibrio cholerae O1, and there was a positive relationship between the CD4(+) T-cell count and vibriocidal responses following vaccination. Nevertheless, seroconversion occurred at a rate of 65% against the Ogawa serotype and 74% against the Inaba serotype in adults with HIV infection. These results suggest that the vaccine retains substantial immunogenicity in adults with HIV infection and may benefit this population by protecting against cholera.

Antibody Secreting Cell Responses following Vaccination with Bivalent Oral Cholera Vaccine among Haitian Adults.

Background The bivalent whole-cell (BivWC) oral cholera vaccine (Shanchol) is effective in preventing cholera. However, evaluations of immune responses following vaccination with BivWC have been limited. To determine whether BivWC induces significant mucosal immune responses, we measured V. cholerae O1 antigen-specific antibody secreting cell (ASC) responses following vaccination. Methodology/Principal Findings We enrolled 24 Haitian adults in this study, and administered doses of oral BivWC vaccine 14 days apart (day 0 and day 14). We drew blood at baseline, and 7 days following each vaccine dose (day 7 and 21). Peripheral blood mononuclear cells (PBMCs) were isolated, and ASCs were enumerated using an ELISPOT assay. Significant increases in Ogawa (6.9 cells per million PBMCs) and Inaba (9.5 cells per million PBMCs) OSP-specific IgA ASCs were detected 7 days following the first dose (P < 0.001), but not the second dose. The magnitude of V. cholerae-specific ASC responses did not appear to be associated with recent exposure to cholera. ASC responses measured against the whole lipolysaccharide (LPS) antigen and the OSP moiety of LPS were equivalent, suggesting that all or nearly all of the LPS response targets the OSP moiety. Conclusions/Significance Immunization with the BivWC oral cholera vaccine induced ASC responses among a cohort of healthy adults in Haiti after a single dose. The second dose of vaccine resulted in minimal ASC responses over baseline, suggesting that the current dosing schedule may not be optimal for boosting mucosal immune responses to V. cholerae antigens for adults in a cholera-endemic area.

Acceptability and use of ready-to-use supplementary food compared to corn–soy blend as a targeted ration in an HIV program in rural Haiti: a qualitative study

Ready-to-use supplementary food (RUSF) is increasingly used as a component of food rations for adults with HIV. We undertook a qualitative study to evaluate the acceptability and use of peanut-based RUSF compared to corn–soy blend (CSB) among adults living with HIV in rural Haiti who had been enrolled in a prospective, randomized trial comparing the impact of those rations. A total of 13 focus groups were conducted with 84 participants—42 selected from the RUSF arm of the study, and 42 from the CSB arm—using a guide with pre-designated core topics and open-ended questions. We found that RUSF was highly acceptable in terms of taste, preparation, and packaging. Both types of food ration were widely shared inside and outside households, especially with children. However, while CSB was without exception stored with the communal household food supply, RUSF was frequently separated from the household food supply and was more often reserved for consumption by individuals with HIV. RUSF was a highly acceptable food ration that, compared to CSB, was more often reserved for use by the individual with HIV. Qualitative examination of the perceptions, use, and sharing of food rations is critical to understanding and improving the efficacy of food assistance for food-insecure people living with HIV.BackgroundReady-to-use supplementary food (RUSF) is increasingly used as a component of food rations for adults with HIV.MethodsWe undertook a qualitative study to evaluate the acceptability and use of peanut-based RUSF compared to corn–soy blend (CSB) among adults living with HIV in rural Haiti who had been enrolled in a prospective, randomized trial comparing the impact of those rations. A total of 13 focus groups were conducted with 84 participants—42 selected from the RUSF arm of the study, and 42 from the CSB arm—using a guide with pre-designated core topics and open-ended questions.ResultsWe found that RUSF was highly acceptable in terms of taste, preparation, and packaging. Both types of food ration were widely shared inside and outside households, especially with children. However, while CSB was without exception stored with the communal household food supply, RUSF was frequently separated from the household food supply and was more often reserved for consumption by individuals with HIV.ConclusionsRUSF was a highly acceptable food ration that, compared to CSB, was more often reserved for use by the individual with HIV. Qualitative examination of the perceptions, use, and sharing of food rations is critical to understanding and improving the efficacy of food assistance for food-insecure people living with HIV.