Risk Factors for Self-Reported Cholera Within HIV-Affected Households in Rural Haiti

Food insecurity and risk of cholera: A cross-sectional study and exploratory analysis of potential mediators

BACKGROUND

Food insecurity has been independently associated with developing cholera and there is an inverse relationship between national food security and annual cholera incidence. However, the factors that mediate the risk of cholera among food insecure households remain largely unexplored.

METHODOLOGY AND PRINCIPAL FINDINGS

In a cross-sectional survey of rural households in Haiti, we explored the role of food behaviors (i.e., dietary choices and food-handling practices) as mediators of cholera risk among food-insecure families. We generated a series of multivariable regression models to test hypothesized associations between the severity of food insecurity (measured by the Household Hunger Scale), hygiene and food behaviors, and history of severe, medically-attended cholera. Moderate household hunger (Adjusted Odds Ratio [AOR] 1.47, 95% Confidence Interval (CI) 1.05-2.04; p = 0.021) and severe hunger (AOR 2.45, 95% CI 1.45-4.15; p = 0.001) were positively associated with a history of severe, medically-attended cholera compared with little to no household hunger. Household hunger was positively associated with three behaviors: antacid use, consumption of leftover non-reheated food, and eating food and beverages prepared outside of the home (i.e., at a restaurant or from a vendor). Consumption of outside food items and antacid use were positively associated with a history of cholera.

CONCLUSION

Our findings suggest that food behaviors may mediate the association between food insecurity and cholera and contribute to an understanding of how interventions could be designed to target food insecurity as part of cholera prevention and control.

The inverse relationship between national food security and annual cholera incidence: a 30-country analysis

Introduction

Individual and household-level evidence suggests a relationship between food insecurity and cholera risk. The relationship between national food security and the size of cholera outbreaks is unknown.

Methods

We analysed the relationship between national food security and annual cholera incidence rate from 2012 to 2015 across 30 countries. We used components of the Global Food Security Index (GFSI) as measures of food security. We included countries with available GFSI reporting cases of cholera during the study period, excluding high-income countries. We developed multivariable zero-inflated negative binomial models with annual cholera incidence rate as the outcome, GFSI components as the exposure of interest, fixed effects for country and year, and time-varying effects related to water, sanitation, and hygiene, oral cholera vaccine deployment, healthcare expenditure, conflict and extreme weather.

Results

The 30 countries reported 550 106 total cases of cholera from 2012 to 2015, with a median annual incidence rate of 3.1 cases per 100 000 people (IQR 0.3–9.9). We found independent inverse relationships between cholera and Overall GFSI (incidence rate ratio (IRR) 0.57, 95% CI 0.43 to 0.78), GFSI-Availability (IRR 0.81, 95% CI 0.70 to 0.95) and GFSI-Affordability (IRR 0.76, 95% CI 0.62 to 0.92).

Conclusions

We identified a strong inverse relationship between national food security and annual incidence rate of cholera. In the context of prior evidence at the individual and household levels, this suggests that there is a linkage between food insecurity and cholera at the national level that should be further considered in assessing cholera risk in vulnerable regions and in designing cholera control interventions.

Health Considerations for HIV-Infected International Travelers

PURPOSE OF THE REVIEW

International travel continues to steadily increase, including leisure travel, travel to one's country of origin to visit friends and relatives, travel for service work, and business travel. Travelers with HIV may have an increased risk for travel-associated infections. The pre-travel medical consultation is an important means of assessing one's risk for travel-related health issues. The aim of this review is to provide an update on key health considerations for the HIV-infected traveler.

RECENT FINDINGS

Like all travelers, the HIV-infected traveler should adhere to behavioral precautions, including safety measures with food and water consumption, safe sexual practices, and arthropod bite avoidance. HIV is a risk factor for venous thromboembolism and patients should be educated regarding this risk. Most pre-travel vaccines are safe and immunogenic in HIV-infected individuals, though live vaccines should be avoided in patients with low CD4 counts. Malaria chemoprophylaxis is strongly recommended in patients with HIV traveling to endemic areas and no significant interactions exist between the commonly used prophylactic anti-malarial agents and anti-retroviral therapy (ART). Travelers with HIV, particularly those who are not on ART or who have low CD4 cell counts, may have increased risk for tuberculosis, malaria, enteric infections, visceral leishmaniasis, American trypanosomiasis, and endemic mycoses such as histoplasmosis, talaromycosis, and coccidioidomycosis. The immune status of the HIV-infected traveler should be assessed prior to travel along with the duration, itinerary, and activities planned during travel in order to carefully consider individual risk for travel-related health issues.

Food insecurity and self-reported cholera in Haitian households: An analysis of the 2012 Demographic and Health Survey

Background

Both cholera and food insecurity tend to occur in impoverished communities where poor access to food, inadequate sanitation, and an unsafe water supply often coexist. The relationship between the two, however, has not been well-characterized.

Methods

We performed a secondary analysis of household-level data from the 2012 Demographic and Health Survey in Haiti, a nationally and sub-nationally representative cross-sectional household survey conducted every five years. We used multivariable logistic regression to evaluate the relationship between household food security (as measured by the Household Hunger Scale) and (1) reported history of cholera since 2010 by any person in the household and (2) reported death by any person in the household from cholera (among households reporting at least one case). We performed a complete case analysis because there were <1% missing data for all variables.

Results

There were 13,181 households in the survey, 2,104 of which reported at least one household member with history of cholera. After adjustment for potential confounders, both moderate hunger in the household [Adjusted Odds Ratio (AOR) 1.51, 95% Confidence Interval (CI) 1.30–1.76; p <.0001] and severe hunger in the household (AOR 1.73, 95% CI 1.45–2.08; p <.0001) were significantly associated with reported history of cholera in the household. Severe hunger in the household (AOR 1.85, 95% CI 1.05–3.26; p = 0.03), but not moderate hunger in the household, was independently associated with reported death from cholera in households with at least one case of cholera.

Conclusions

In this study we identified an independent relationship between household food insecurity and both reported history of cholera and death from cholera in a general population. The directionality of this relationship is uncertain and should be further explored in future prospective research.

In this study, we identified an independent relationship between household food insecurity, defined as a persistent lack of access to food in adequate quantity or quality and measured using the Household Hunger Scale, and reported history of cholera and death from cholera in a general population. We performed a secondary analysis of household-level data from the 2012 Demographic and Health Survey (DHS) in Haiti, a nationally and sub-nationally representative cross-sectional household survey conducted every five years. The 2012 survey was conducted during the height of the cholera epidemic, with 453,536 suspected cases and 3,835 deaths in Haiti from 2011–2012. We used multivariable logistic regression to control for measured confounders. The underlying mechanisms and directionality of the association between food insecurity and reported history of cholera are uncertain and should be explored in future prospective research. A better understanding of the relationship between food insecurity and cholera could inform both future cholera outbreak prediction and response, particularly in settings where poor food access and cholera risk factors are known to co-exist.

A Metagenomic Approach to Evaluating Surface Water Quality in Haiti

The cholera epidemic that occurred in Haiti post-earthquake in 2010 has resulted in over 9000 deaths during the past eight years. Currently, morbidity and mortality rates for cholera have declined, but cholera cases still occur on a daily basis. One continuing issue is an inability to accurately predict and identify when cholera outbreaks might occur. To explore this surveillance gap, a metagenomic approach employing environmental samples was taken. In this study, surface water samples were collected at two time points from several sites near the original epicenter of the cholera outbreak in the Central Plateau of Haiti. These samples underwent whole genome sequencing and subsequent metagenomic analysis to characterize the microbial community of bacteria, fungi, protists, and viruses, and to identify antibiotic resistance and virulence associated genes. Replicates from sites were analyzed by principle components analysis, and distinct genomic profiles were obtained for each site. Cholera toxin converting phage was detected at one site, and Shiga toxin converting phages at several sites. Members of the Acinetobacter family were frequently detected in samples, including members implicated in waterborne diseases. These results indicate a metagenomic approach to evaluating water samples can be useful for source tracking and the surveillance of pathogens such as Vibrio cholerae over time, as well as for monitoring virulence factors such as cholera toxin.