Food Protection Trends - August 2010 - 488

FIGURE 5. Mortality by region, 2008

Deaths linked to the outbreak reports were less common in this region than in the others. Deaths were reported in 14% of the outbreak reports, and half of these deaths were linked to Salmonella (Fig. 5).

Africa
Africa reported the largest number of outbreaks among the three geographical regions included in this study, with a total of 128 reported in 2008. The region is unique in many ways, such as seasonality, vehicle, size of the outbreaks and number of illnesses and deaths associated with outbreaks. Because of its less developed public health sector, the role of the media in outbreak reporting becomes more relevant and important for assessing the public health impacts of contaminated food or water. The largest number of outbreaks was reported in the first quarter (51), followed by the fourth (38), second (25) and third (14). In 2008, waterborne disease outbreaks that were diagnosed as cholera were more frequent, larger, and more severe in the end of the fourth and beginning of the first quarters, during the rainy season (Fig. 1). Unlike the outbreaks in the other two regions included in this study, only a small percentage of reported outbreaks in Africa were specifically linked to food consumption. In the first quarter, water was identified as the

dominant vehicle (more than 50%), while in the other quarters, most reports did not identify a vehicle (Fig. 2). Vibrio cholerae was the most frequently reported pathogen in this region, identified in 71% to 86% of the reports, depending on the quarter. Contaminated food and water were the likely vehicles of exposure, though the exact route was frequently unspecified and probably not known. The lack of a specified vehicle may indicate that the surveillance system in this region was relatively ineffective in determining causation (Table 1). A government-issued warning or recall was mentioned in 20% of the reports (Fig. 3). The size of the outbreaks reported from Africa was larger than in any of the other regions included in this study. In the first two quarters of the year, onethird of reported outbreaks had 101– 1,000 illnesses. In the third quarter, 43% of the reported outbreaks had 11–100 illnesses, while outbreaks of 101–1,000 persons were reported in 14%. The final quarter (Oct., Nov., Dec.) had a unique distribution: 29% of the outbreaks were in the 11–100 range, 18% in the 101– 1,000 range, and 24% over 1001 (Fig. 4). In the final quarter of 2008, a very large cholera outbreak began in Zimbabwe and spread to surrounding countries as refugees crossed borders. Five other countries (Botswana, Mozambique, Malawi, South Africa and Zambia) reported outbreaks linked to the one that origi-

nated in Zimbabwe (17). These outbreaks were counted as six separate outbreaks in that quarter, because of the number of countries involved, with morbidity estimates ranging from 8 to over 26,000. The death rate associated with outbreaks in Africa was comparatively high. Mortality was reported in 70% of the outbreak reports, with mortality of 1–10 persons in 41% of outbreaks. In the final quarter, the number of outbreaks with mortality of over 100 persons rose to 42% (Fig. 5). Note: The researchers analyzed outbreak reports collected in the first quarter of 2009 in both English and French for the African region and found that most outbreaks were reported in both languages. This resulted in part from the involvement of the WHO and other international non-governmental organizations that work extensively in the African region and publish their reports in multiple languages. For example, in March 2009, only two reports were carried in French exclusively and not accessed by our regular methods of information gathering.

Western Pacific
A total of 118 reports from the Western Pacific region in 2008 were analyzed. This region includes economically developed and developing countries. There was consistent reporting in English from Australia, New Zealand and a number of Asian nations in the region, including Japan and the Philippines. Reported outbreaks did not show a seasonal trend in this region, which is not surprising because the region covers countries on both sides of the equator. Outbreak reports in the four quarters ranged from 33 to 27. The percent of cholera outbreaks increased over each successive quarter, from 9% in the first quarter to 19% in the second, 20% in the third, and 25% in the fourth (Fig. 1). Food, the most common vehicle of the reported outbreaks, was implicated in the majority of reports from the Western Pacific region in each of the quarters. The next most reported vehicle was “unspecified” in three of the quarters (Fig. 2). No specific pathogen dominated the reports. Reports used less specific terms, such as “contamination” and “gastroenteritis,” with greater regularity. “Gastro-

488 FOOD PROTECTION TRENDS | AUGUST 2010

Food Protection Trends - August 2010

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