Combating Cholera Caused by Climate Change in Bangladesh (C₅)

Since John Snow discovered that the Broad Street pump was responsible for the London cholera outbreak in 1855, scholars have searched for associations between contaminated drinking water and cholera cases. While other studies have shown the role of hygiene, sanitation, population density and food in the spread of cholera, the main focus remains on primary transmission through drinking water.

However, the possible association between cholera and water quantity is still unknown. Given current climate change projections of more severe droughts and floods, water stress in expected to increase in Bangladesh. Therefore, it is essential to understand what kind of an effect water stress will have on cholera prevalence.

The idea for this study originates in Pakistan where Jensen et al. showed that diarrhea prevalence is significantly more related to water quantity than water quality. Furthermore, E. coli counts (water quality indicator for fecal contamination) in drinking and domestic water have an insignificant association to diarrheal prevalence unless a household is using approximately 100 liters per person per day – a quantity similar to the average in developed nations.

Water conditions in Bangladesh:

Bangladesh is expected to be one of the countries most affected by climate change due to multiple climate related hazards: increasing sea level, as well as increased inlands floods, droughts and cyclones.

The country already suffers from annual floods and droughts that affect up to 70% of the country and cause countrywide water stress. This situation of biannual water stress is expected to be even further intensified by India’s political decisions to dam and hereby control the water flow of the three major rivers feeding into the country.

For Bangladesh’s 160 million people, of whom many are surviving for less than a dollar per day, the household water availability is not only a human right in itself but also a crucial element in combating life threatening infectious diseases. One such disease is cholera – one of the most studied deadly diseases that is native to Bangladesh.

Cholera:

Cholera is a life-threatening diarrheal disease. The Vibrio cholerae (V. cholerae) bacteria that causes cholera will survive whenever the human environment is degraded by poverty and overcrowding and when population is displaced by disasters and conflicts. The complex patterns of human behavior and its interaction with ecological and biological characteristics of V. cholerae that foster the transmission of the disease will continue to make cholera a global public health challenge for the twenty-first century.

Burden: Bangladesh is expected to be one of the countries most affected by climate change, which is expected to cause various water stress scenarios across the country. Cholera, a deadly water-borne and fecal-oral disease, is endemic in Bangladesh.

Knowledge gap: It is unknown how water stress affects cholera prevalence and how climate change may affect cholera prevalence in terms of water stress. This study intends to investigate the associations between water quantity, water quality and cholera.

Study site: Arichpur is a 1.2 km2 urban community located 15 km north of Dhaka, Bangladesh in the Tongi sub-district. Arichpur has approximately 129,000 individuals and 29,000 households where many nuclear families share one room, and 10-15 families share a stove, toilet, and water source. Some households are also made up of a single room that is shared by migrant workers.

Relevance: Tongi has a reportedly high cholera incidence. Cholera identification prevalence in Tongi is currently under investigation by a pilot study entitled, “Investigation the transmission of cholera in Arichpur, Tongi: A pilot study.” This study will run alongside the current study but focuses on the association between water stress and cholera.

Hypothesis: Our hypothesis is that water availability is more important than water quality in cholera prevalence, which will result in climate change having an even greater impact on cholera prevalence than current models predict through its impact on water availability and subsequently human behavior.

Overall objective:

To analyze the risk attributable to water stress on cholera prevalence in a low-income urban community in Bangladesh.

Objectives:

1. To analyze water stress in terms water access, storage and use for personal and domestic purposes under seasonal climate variability

2. To analyze the association of domestic water use with cholera infections

3. To examine seasonal changes in patterns of water use, perceptions on water use, food practices and environmental, domestic and personal hygiene adaptations

4. To determine the variability in microbiological contamination of domestic contamination hotspots identified as being important for cholera transmission objective 3

5. To analyze the association between domestic water quality and cholera infections

6. To predict the effect of climate change on water availability and quality in the household under different climactic and political scenarios

Because Bangladesh is expected to be one of the countries most affected by climate change, it is important to understand the various outcomes of the projected changes in climate.

Water availability will certainly be affected by projected climate change, yet the effects of this in terms of household responses and cholera have not yet been studied. Furthermore, cholera transmission routes are still poorly understood and the true burden of the disease is unknown.

Most studies rely on clinic and hospital-based surveillance, which miss the more frequent mild and moderate infections. These mildly and moderately symptomatic cholera infections are thought to play an important role in the spread of the disease.

By investigating the unknown characteristics of cholera and outcomes of climate change, interventions and policy can be more effectively targeted for cholera prevention and control and control in Bangladesh. 

This study will measure the incidence of cholera infections at the household-level within a cohort of 400 people over the course of two years, adding to a better understand of the burden of the disease in urban Bangladesh. 

Furthermore, it will analyze the associations between cholera, water stress, -quality and -hygiene and sanitation behaviors in order to make projections on how future water stress scenarios could influence the incidence of cholera in Bangladesh.

The overall aim of the Choleraphone is to establish a novel method for identification of diarrhoea cases in a study population in Bangladesh through a mobile telephone reporting system.

The specific objectives of this project are to:

• Conduct a literature review of related Mobile health technologies and mobile sampling methods.
• Design the mobile reporting system and to implement it in households of the cohort households.
• Evaluate the sensitivity and specificity of the method through interviews with a randomly selected subset of households in the cohort.

Project description:

The distribution and magnitude of cholera in non-hospitalized cases in Bangladesh is still largely unknown. The Choleraphone will develop a novel method for household surveillance of cholera in Bangladesh through a mobile telephone reporting system of diarrhoea cases.

This system addresses the problem of diarrheal recall, which is optimal within 48 hours. Previous diarrhoea studies have shown that recall periods longer than 48 hours are prone to recall bias. However, limitations of funding and manpower make 48 hour sampling impossible in many settings.

Choleraphone attempts to tackle this issue by providing a mobile phone to each participant in the cohort. Participants will be trained on how to identify diarrhoea and how to report it the day it occurs by calling the project’s medical officer using their Choleraphones. A recorded refresher lesson and reminders on reporting will be given to participants via the Choleraphone at regular intervals. This way we hope to greatly decrease the recall bias for diarrhoeal cases through innovative mobile surveillance.

Previous studies have shown that the Bangladeshi population is very positive about the usage of mobile phones, especially because of the ability to convey emergency warning messages. Based on current work in the project area, it is assumed that at least one person in every family has a mobile phone.

Peer-reviewed studies have also shown promising results in Mobile health (a term used for the practice of medicine and public health, supported by mobile devices), reducing transmission delays and error rates in disease surveillance, as well as saving time compared to conventional paper-based reporting systems. However, Mobile health has never been applied in studies concerning diarrhoea or cholera in Bangladesh or elsewhere.

Research Plan:

1. Preparation for field study and project implementation at the University of Copenhagen
2. January 2014 – December 2015: Field study and project implementation in Bangladesh (International Centre for Diarrhoeal Disease Research, Bangladesh, University of Dhaka, B)
3. Data processing and writing of findings in Denmark

Examining the potential effects of Climate Change on cholera and its implications to Human Security in Bangladesh

Project description:

A PhD study using mixed methods approaches to study the impacts of floods on hygiene and sanitation, and health indicators (diarrhoea and Cholera), with analysis' of security aspects of these impacts on human livelihood.

Person in charge of project:

Stephen Lawrence Grant

Partner Institutions:

Centre for Advanced Security Theory (CAST), Department of Political Sciences, University of Copenhagen

Environment and Population Research Centre (EPRC), Bangladesh

Research team:

• Stephen Lawrence Grant
• Peter Kjær Mackie Jensen
• Ole Wæver, CAST
• Bilqis Hoque (EPRC)

Project timeline:

2010-2018

Principle Investigators:

Dr. Peter Kjær Mackie Jensen (Denmark)

Dr. Emily Gurley (Bangladesh)

Partner Institutions:

• Bangladesh University of Engineering and Technology (BUET)
• University of Dhaka (DU)
• International Centre for Diarrheal Disease Research (icddr,b)

Research team:

• Dr. Emily Gurley (icddr,b)
• Professor Anowara Begum (DU)
• Professor Sirajul Islam Khan (DU)
• Jannataul Ferdous (DU)
• Zenat Zebin Hossain (DU)
• Professor Akm Saiful Islam (BUET)
• Rebeca Sultana (icddr,b and JNU)
• Associate Professor Peter Kjær Mackie Jensen (University of Copenhagen)
• Charlotte Tamason (University of Copenhagen)
• Leela Charlotte Sengupta (University of Copenhagen)

Sponsor:

Combating cholera caused by climate change is sponsored by Danida, Council for Development Research, Ministry of Foreign Affairs of Denmark