EHP Library Hygiene Bulletin

In this issue:

• New Reports/Newsletters
  • EHP: Prevention of Diarrhea through Improvement of Hygiene Behaviors: the SAFE Pilot Project Experience
  • IRC: Sustainability of Changes in Hygiene Behaviour newsletter, July 2002.
• Abstracts of Recent Studies
  • Identifying Environmental Risk factors for Endemic Cholera: a Raster GIS approach.
  • Disease Transmission Models for Public Health Decision Making: Analysis of Epidemic and Endemic Conditions Caused by Waterborne Pathogens
  • Epidemic and Endemic Cholera Trends over a 33-Year Period in Bangladesh.
  • Cholera in Brazil during 1991-1998: socioeconomic characterization of affected areas
• Cholera Outbreak Update
  • Burundi
  • Democratic Republic of the Congo

New Reports/Newsletters       

• EHP: Prevention of Diarrhea through Improvement of Hygiene Behaviors: the SAFE Pilot Project Experience. (Click on title to view report) 

The Sanitation and Family Education pilot project implemented by CARE/Bangladesh with technical assistance from the International Centre for Diarrheal Disease Research, Bangladesh (ICDDR,B), focused on the “software” aspects of water, sanitation and hygiene, in particular, hygiene promotion for diarrhea prevention. The SAFE results clearly showed the importance of hygiene promotion to achieve health outcomes.

• New from IRC: Sustainability of changes in hygiene behavior newsletter, July 2002. (click on title to view newsletter)This is the second newsletter informing about IRC’s multi-country research into the sustainability of changes in hygiene behaviour. It provides an overview of some preliminary findings of the study. 

Abstracts of Recent Studies

Health Place 2002 Sep;8(3):201-10

Identifying environmental risk factors for endemic cholera: a raster GIS approach.

Ali M, Emch M, Donnay JP, Yunus M, Sack RB.

The bacteria that cause cholera are known to be normal inhabitants of surface water, however, the environmental risk factors for different biotypes of cholera are not well understood. This study identifies environmental risk factors for cholera in an endemic area of Bangladesh using a geographic information systems (GIS) approach. The study data were collected from a longitudinal health and demographic surveillance system and the data were integrated within a geographic information system database of the research area. Two study periods were chosen because they had different dominant biotypes of the disease. From 1992 to 1996 El Tor cholera was dominant and from 1983 to 1987 classical cholera was dominant. The study found the same three risk factors for the two biotypes of cholera including proximity to surface water, high population density, and poor educational level. The GIS database was used to measure the risk factors and spatial filtering techniques were employed. These robust spatial methods are offered as an example for future epidemiological research efforts that define environmental risk factors for infectious diseases.

Environmental Health Perspectives Volume 110, Number 8, August 2002 

Disease Transmission Models for Public Health Decision Making: Analysis of Epidemic and Endemic Conditions Caused by Waterborne Pathogens
(send an email to obtain the complete article as a pdf file)
Joseph N. S. Eisenberg,1,2 M. Alan Brookhart,2 Glenn Rice,3 Mary Brown,3 and John M. Colford, Jr.1,2 

1Center for Occupational and Environmental Health and 2School of Public Health, University of California, Berkeley, California, USA; 3U.S. Environmental Protection Agency, Office of Research and Development /National Center for Environmental Assessment, Cincinnati, Ohio, USA 

Developing effective policy for environmental health issues requires integrating large collections of information that are diverse, highly variable, and uncertain. Despite these uncertainties in the science, decisions must be made. These decisions often have been based on risk assessment. We argue that two important features of risk assessment are to identify research needs and to provide information for decision making. One type of information that a model can provide is the sensitivity of making one decision over another on factors that drive public health risk. To achieve this goal, a risk assessment framework must be based on a description of the exposure and disease processes. Regarding exposure to waterborne pathogens, the appropriate framework is one that explicitly models the disease transmission pathways of pathogens. This approach provides a crucial link between science and policy. Two studies–a Giardia risk assessment case study and an analysis of the 1993 Milwaukee, Wisconsin, Cryptosporidium outbreak–illustrate the role that models can play in policy making. 

    J Infect Dis 2002 Jul 15;186(2):246-51 

Epidemic and Endemic Cholera Trends over a 33-Year Period in Bangladesh.

Longini Jr IM, Yunus M, Zaman K, Siddique AK, Sack RB, Nizam A.

Department of Biostatistics, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, USA. 
[email protected]

      Despite nearly 200 years of study, the mechanisms contributing to the maintenance of endemic cholera and the causes of periodic epidemics remain poorly understood. To investigate these patterns, cholera data collected over 33 years (1966-1998) in Matlab, Bangladesh, were analyzed. Time-lagged autocorrelations were stratified by Vibrio cholerae serogroup, serotype, and biotype. Both classical and El Tor biotypes alternated and persisted between 1966 and 1988; the classical biotype disappeared by 1988, and the O139 serogroup first appeared in 1993. Both the Ogawa and Inaba serotypes circulated the entire time. The autocorrelations revealed that both Inaba and Ogawa epidemics were followed 12 months later by epidemics of the same serotype. Ogawa epidemics, however, were also followed by further Ogawa epidemics only 6 months later. Thus, epidemics of Inaba may selectively confer short-term population-level immunity for a longer period than those of Ogawa. These observations suggest that the Inaba antigen should be maximized in cholera vaccine designs.

J Health Popul Nutr 2002 Mar;20(1):85-92 

Cholera in Brazil during 1991-1998: socioeconomic characterization of affected areas.

Waldman EA, Antunes JL, Nichiata LY, Takahashi RF, Cacavallo RC.

School of Public Health, University of Sao Paulo, SP, Brazil. [email protected]

      The paper describes the trends in, and spatial patterns of, the incidence of cholera in Brazil from 1991 to 1998. During this period, 161,432 cases and 1,296 deaths from cholera were reported. The poorest (North and Northeast) regions of the country had the highest morbidity and mortality rates. The remaining regions had self-limited outbreaks. Seventy-eight percent of affected municipalities had populations of fewer than 30,000, and about 65% of them lived in rural areas.

The affected municipalities of the North and Northeast regions had consistent indications of deprivation: average Human Development Index was 0.41, infant mortality rate 90.3%, average life expectancy 59.4 years, and adult illiteracy rate 46.5%. The epidemiological profile of the disease in Brazil highlights intra- and inter-regional socioeconomic differentials in the country and indicates the importance of planning and implementing public-health interventions and specific policies aimed at reducing health inequalities.

Cholera Update – August 2, 2002

Source: http://www.promedmail.org ProMED-mail is a program of the
International Society for Infectious Diseases

Cholera in Africa: [1] Burundi; [2] Democratic Republic of the Congo

[1] Burundi
Date: Tue, 30 Jul 2002 From: Pablo Nart <[email protected]>
Source:The Monitor (Uganda) 29 Jul 2002 [edited]


A total of 6 out of 454 people known to be infected with cholera in Burundi have died since the disease broke out in the central African country in mid-June 2002, the health ministry said on Fri 27 Jul 2002. Jean Rirangira, the country’s general director of public health, said the worst-hit regions were those north and northeast of the capital Bujumbura, where 356 cases and 3 deaths have been recorded since 17 Jul 2002. He said that the northwestern Cibitoke province had registered 70 cases and 3 deaths, while neighboring Bubanza province has registered 28 cases of cholera.

“The big problem in Burundi is access to potable water,” Rirangira said, adding that officials had set up 2 treatment centers in central and rural Bujumbura. “They’re working 24 hours a day,” he said. “They distribute potable water or chlorine to disinfect the water.”

The disease invaded west Africa in 1970, more than a century after it was last seen in the region, according to the UN World Health Organization.  The disease quickly spread, and eventually became endemic to most of the African continent.

******
[2] Democratic Republic of the Congo
Date: Mon, 29 Jul 2002 From: Pablo Nart <[email protected]>
Source: Allafrica.com, 25 Jul 2002 [edited]

The United Nations Children’s Fund (UNICEF) has mobilised 10 metric tons of emergency relief supplies worth US $64 000 to fight a cholera outbreak in Kalemie, in the north of Katanga Province, southeastern Democratic Republic of the Congo (DRC), according to a UNICEF press release issued on Wed 24 Jul 2002.

The supplies included 4000 liters of serum, 1000 kg of chlorine, 40 000 packets of oral rehydration salts, and 200 units of plastic sheeting, which had been delivered to Kalemie and immediately distributed. The International Rescue Committee, UNICEF’s principal partner in caring for victims of this epidemic, had meanwhile benefited from the construction of an auxiliary shelter and 70 beds, UNICEF said.

The cholera treatment center of Kalemie General Hospital has reported 360 cases of cholera among children aged 5 years and under since the outbreak of the epidemic at the start of July 2002. According to UNICEF, the mortality rate of children aged 5 years and under due to cholera in Kalemie has risen from 1 per cent to 3.6 per cent.

The outbreak began when the city’s water supply system failed, forcing its estimated 120 000 residents to collect water from nearby Lake Tanganyika and local rivers. Relief agencies had installed water reservoirs in several neighborhoods of the city, and water treatment teams had been posted to locations along rivers and the lake from which residents had been drawing water, UNICEF said.

Also working with ICRC are Save the Children, Medecins Sans Frontieres, the Italian NGO ALISEI, & MONUC, the UN peacekeeping mission in the DRC The CDC notes that a person may get cholera by drinking water or eating food contaminated with the cholera bacterium. In an epidemic, the source of the contamination is usually the feces of an infected person. The disease can spread rapidly in areas with inadequate treatment of sewage and drinking water. The cholera bacterium may also live in the environment in brackish rivers and coastal waters. The disease is unlikely to spread directly from one person to another: therefore, casual contact with an infected person is not a risk for becoming ill.