Effects of Ufra Disease on Yield Loss of Deepwater Rice in Bangladesh

Abstract

Ufra, caused by the stem nematode, Ditylenchus angustus (Butler, 1913) Filipjev, 1936, is a serious disease of deepwater rice in southern Bangladesh. It was studied between 1977 and 1979 as part of a joint project with the Overseas Development Administration at the Bangladesh Rice Research Institute. Three symptom types are distinguished according to the extent of panicle emergence: Ufra1 (none), Ufra2 (partial) and Ufra3 (complete). All three represent total loss from that panicle. The number of Ufra2 as a percentage of the total number of panicles present in a specified area is selected as a disease index (UfraII). A function relating yield to the level of UfraII is proposed on the basis of selective samples from a field with a well-defined ufra patch. This function is compared with another derived from random samples in different fields along a linear transect through an area where ufra is endemic. Loss of panicle density, i.e. panicles/m², is identified as a major component of yield loss, approximately equal to the loss associated with all three symptom types added together. Although severe and widely distributed throughout the southern part of the deepwater rice region in 1977 and 1978, it was very difficult to find in 1979 when there was a spring drought. Ufra is worse in wet years, in areas which flood early, and where the crop is harvested late. The length of the over-winter decay phase appears to be a critical factor regulating the survival of the pathogen from one season to the next. This suggests an approach for ufra control.     

Investigation of the Concurrent Emergence of Salmonella enteritidis in Humans and Poultry in British Columbia,Canada, 2008–2010

An increase in the rate of human infections with Salmonella enteritidis (SE) occurred between 2007 and 2010 in British Columbia (BC). During the same time period, an increase in SE from poultry‐sourced isolates and increased clinical severity in poultry were also observed in BC. This article describes a multi‐sectoral collaboration during a 3‐year investigation, and the actions taken by public health and animal health professionals. Human cases were interviewed, clusters were investigated, and a case–control study was conducted. Environmental investigations were conducted in food service establishments (FSE). Suspect foods were tested. Laboratory data from poultry‐sourced isolates were analysed. Five hundred and eighty‐four human cases of SE with the same pulsed‐field gel electrophoresis pattern were identified between May 2008 and August 2010. Seventy‐three percentage of cases reported consumption of eggs. The odds of egg consumption were 2.4 times higher for cases than controls. Implicated FSE were found to use ungraded eggs, which had been distributed illegally. Investigation suggested that there were multiple suppliers of these eggs. Collaboration between public health and animal health professionals led to data sharing, improved understanding of SE, engagement with the poultry industry and public communication. Multi‐disciplinary, multi‐sectoral and multi‐pronged investigations are recommended to identify the likely source of illness in large, protracted foodborne outbreaks caused by commonly consumed foods.