World Health Organization Estimates of the Relative Contributions of Food to the Burden of Disease Due to Selected Foodborne Hazards: A Structured Expert Elicitation

Background The Foodborne Disease Burden Epidemiology Reference Group (FERG) was established in 2007 by the World Health Organization (WHO) to estimate the global burden of foodborne diseases (FBDs). This estimation is complicated because most of the hazards causing FBD are not transmitted solely by food; most have several potential exposure routes consisting of transmission from animals, by humans, and via environmental routes including water. This paper describes an expert elicitation study conducted by the FERG Source Attribution Task Force to estimate the relative contribution of food to the global burden of diseases commonly transmitted through the consumption of food. Methods and Findings We applied structured expert judgment using Cooke’s Classical Model to obtain estimates for 14 subregions for the relative contributions of different transmission pathways for eleven diarrheal diseases, seven other infectious diseases and one chemical (lead). Experts were identified through international networks followed by social network sampling. Final selection of experts was based on their experience including international working experience. Enrolled experts were scored on their ability to judge uncertainty accurately and informatively using a series of subject-matter specific ‘seed’ questions whose answers are unknown to the experts at the time they are interviewed. Trained facilitators elicited the 5th, and 50th and 95th percentile responses to seed questions through telephone interviews. Cooke’s Classical Model uses responses to the seed questions to weigh and aggregate expert responses. After this interview, the experts were asked to provide 5th, 50th, and 95th percentile estimates for the ‘target’ questions regarding disease transmission routes. A total of 72 experts were enrolled in the study. Ten panels were global, meaning that the experts should provide estimates for all 14 subregions, whereas the nine panels were subregional, with experts providing estimates for one or more subregions, depending on their experience in the region. The size of the 19 hazard-specific panels ranged from 6 to 15 persons with several experts serving on more than one panel. Pathogens with animal reservoirs (e.g. non-typhoidal Salmonella spp. and Toxoplasma gondii) were in general assessed by the experts to have a higher proportion of illnesses attributable to food than pathogens with mainly a human reservoir, where human-to-human transmission (e.g. Shigella spp. and Norovirus) or waterborne transmission (e.g. Salmonella Typhi and Vibrio cholerae) were judged to dominate. For many pathogens, the foodborne route was assessed relatively more important in developed subregions than in developing subregions. The main exposure routes for lead varied across subregions, with the foodborne route being assessed most important only in two subregions of the European region. Conclusions For the first time, we present worldwide estimates of the proportion of specific diseases attributable to food and other major transmission routes. These findings are essential for global burden of FBD estimates. While gaps exist, we believe the estimates presented here are the best current source of guidance to support decision makers when allocating resources for control and intervention, and for future research initiatives.

Under-5 years mortality rate Access to improved water and Sanitation Among all WHO sub-regions, what was the largest regional percentage point increase from 2000 to 2009 in the proportion of regional vegetable supply (tonnes) that was imported rather than produced domestically?
Please express your answer in absolute terms.

Questions about change in access to improved water or improved sanitation
Background for questions 3.1. and 3.2: The World Health Organization and United Nations Childrens Fund, Joint Measurement Programme (JMP) has published estimates of percent of national population with access to improved sanitatidon for most countries in the world since 1990. Access to improved sanitation facilities is defined as "the percentage of national population with at least adequate access to excreta disposal facilities that can effectively prevent human, animal, and insect contact with excreta. Improved facilities range from simple but protected pit latrines to flush toilets with a sewerage connection. To be effective, facilities must be correctly constructed and properly maintained." ( Based on the JMP data, for each of the above sub-regions, one could calculate the average national percentage point increase from 1990 to 2010 in each sub-region in access to improved sanitations. For example, one could calculate the average national increase in the percentage of population with access to sanitation among nations in the WHO Africa D (AFR D) region.
Think of the sub-region listed above that had the largest average national increase from 1990 to 2010 in the percentage of national population with access to sanitation. What was this increase?
Please express your answer in positive percentage points.

Background:
The World Health Organization and United Nations Childrens Fund, Joint Measurement Programme (JMP) has published estimates of percent of national population with access to improved drinking water for most countries in the world since 1990. Access to improved drinking water is defined as the "percentage of the population with reasonable access to an adequate amount of water from an improved source, such as a household connection, public standpipe, borehole, protected well or spring, and rainwater collection. Reasonable access is defined as the availability of at least 20 liters a person a day from a source within one kilometer of the dwelling." ( ). Under this programme, laying flocks must be sampled for these pathogens every 15 th week during the production period and results of these tests must be reported to EFSA annually. These results are included in the EFSA/ECDC annual report, "Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks". The following questions refer to these annual EFSA/ECDC reports.
What will be the percent positive among these samples of laying flocks for all reporting EU member states in 2012?  (2003), Ghana (2003) and Mali (2006) and parasitology survey data collected by the Schistosomiasis Control Initiative from school-aged children in Burkina Faso (2007), Ghana (2008), andMali (2007). They used this to estimate the population attributable fraction of hookworm due to living in a home with a soil floor in West Africa, i.e., the percent of hookworm disease that is caused by living in a home with a dirt floor. What was their estimate, as a percentage? Do you know the answer to this question with substantial certainty because you are worked on this study? ___________ (2005) conducted a systematic review and meta-analysis to compare the evidence of relative effectiveness of improvements in drinking water, sanitation facilities, and hygiene practices in less developed countries in reducing diarrheal illness. The study included only published studies that reported diarrheal illness not associated with an outbreak as the health outcome. Metaanalysis was used to estimate the relative risk of diarrheal illness with and without each of these interventions and in combination.

Background: Fewtrell et al
Hygiene interventions were defined as "those that included hygiene and health education and the encouragement of specific behaviours, such as handwashing." (p. 43). "Sanitation interventions were those that provided some means of excreta disposal, usually latrines (either public or household). Water supply inteventions included the provision of a new or improved water supply, or improved distribution (such as the installation of a hand pump or household connection). This could be at the public level or household level. Water quality interventions were related to the provision of water treatment for the removal of microbial contaminants, either at the source or at the household level. Multiple inteventions were those which introduced water, sanitation and hygiene or health education) elements to the study population.
Fewtrell et al (2005) include a meta-analysis of 5 studies was used to estimate the relative risk of diarrheal illness with and without multiple interventions. What was the estimated relative risk?
Remember relative risk is between 0 and 1.  ) 3. In 2010, the UN Environmental Programme published a final review of scientific information on lead.
In this review they reported mean blood lead levels for children in a number of countries.
What did the UNEP Final Review of Scientific Information on Lead report in 2010 as the mean blood lead level for children in Nigeria?
Please express your answer as positive micrograms per deciliter (µg/dL).