Prevalence of leptospira infection in rodents from Bangladesh
Krijger, Inge M. ; Ahmed, Ahmed A.A. ; Goris, Marga G.A. ; Groot Koerkamp, Peter W.G. ; Meerburg, Bastiaan G. - \ 2019
International Journal of Environmental Research and Public Health 16 (2019)12. - ISSN 1661-7827
Food safety - Leptospirosis - Reservoir - Rodents - Zoonosis
Worldwide, Leptospira infection poses an increasing public health problem. In 2008, leptospirosis was recognised as a re-emerging zoonosis of global importance with South-East Asia being one of the most significant centres of the disease. Rodents are thought to be the most important host for a variety of Leptospira serovars. Because Bangladesh offers a suitable humid climate for the survival of these pathogenic bacteria, the presence of rodents could be a serious risk for human infection, especially in peri-urban areas or locations where food is stored. In order to gain more understanding of the multi-host epidemiology, a prevalence study was conducted in Comilla, Bangladesh to determine the presence of pathogenic Leptospira species in rodents. Real-time Polymerase Chain Reaction (qPCR) and sequencing showed that 13.1% (61/465) of the trapped rodents were infected with pathogenic Leptospira. Sequencing of the qPCR products identified the presence of three species: Leptospira interrogans, Leptospira borgpetersenii, and Leptospira kirschneri. Rodents of the genus, Bandicota, were significantly more likely to be positive than those of the genus, Rattus and Mus. Our results confirm the importance of rodents as hosts of pathogenic Leptospira and indicate that human exposure to pathogenic Leptospira may be considerable, also in places where food (rice) is stored for longer times. This study emphasizes the need to improve rodent management at such locations and to further quantify the public health impacts of this neglected emerging zoonosis in Bangladesh.
Assessing the impact of human interventions on floods and low flows in the Wei River Basin in China using the LISFLOOD model
Gai, Lingtong ; Nunes, João P. ; Baartman, Jantiene E.M. ; Zhang, Hongming ; Wang, Fei ; Roo, Ad de; Ritsema, Coen J. ; Geissen, Violette - \ 2019
Science of the Total Environment 653 (2019). - ISSN 0048-9697 - p. 1077 - 1094.
Flood return period - Hydrological model - Land use - LISFLOOD - Reservoir - Water diversion
Floods are extreme hydroclimatic events that threaten societies and ecosystems. The effects of these events are greatly influenced by the changes that humans have imposed on the environment. The LISFLOOD model is a physically based rainfall-runoff model that simulates the hydrological processes in a catchment. Using globally available land cover, soil, and vegetation as well as meteorological and geographical datasets as input, the LISFLOOD model has the potential to be applied worldwide, even for regions where data are lacking. This study first calibrated and validated the LISFLOOD model in the Wei River Basin in China (432,000 km2) for the years between 2000 and 2010 at 0.05° resolution with a monthly Nash-Sutcliffe model efficiency coefficient of 0.79 at the Huaxian station located at the catchment outlet. The outlets of 17 tributaries draining into the main river were then identified in order to assess the contribution of each tributary to the total runoff occurring as a result of flooding. Four categories of scenarios focusing on human interventions in the basin were created and evaluated: 1) Business as usual, 2) Additional reservoirs constructed in different catchments, 3) Land use as in 1980, and 4) Water diversion plan with a pipeline injection of a fixed daily inflow from an adjacent catchment. The results of the scenarios are presented for three strategically important cities located on the floodplain. In general, the construction of the reservoirs could have an effect on reducing peak flows and decreasing the flood return periods while increasing the low flows. The water diversion plan scenarios increased the low flow by 41 times averaged for the three cities. In conclusion, the LISFLOOD model is a sophisticated model for land and water management planning on the catchment scale for reducing the effects of flood and drought.
Campylobacter epidemiology-sources and routes of transmission for human infection
Newell, Diane G. ; Mughini-Gras, Lapo ; Kalupahana, R.S. ; Wagenaar, Jaap A. - \ 2017
In: Campylobacter: Features, Detection, and Prevention of Foodborne Disease / Klein, Günter, Elsevier Inc. Academic Press - ISBN 9780128036235 - p. 85 - 110.
Campylobacter - Environment - Epidemiology - Outbreak - Reservoir - Source attribution - Subtyping - Transmission route
The identification of the sources and routes of transmission of Campylobacter jejuni/coli is essential to the prevention and control of human campylobacteriosis. However, this has proved a significant challenge over the past 35 years because these organisms were so unlike other enteric bacteria, especially Escherichia coli and Salmonella spp. Our current understanding of Campylobacter epidemiology is derived from a range of approaches, including epidemiological studies, and microbiological subtyping. These approaches indicate that poultry is the primary reservoir for campylobacters causing human disease. However, although campylobacteriosis is generally considered a foodborne disease primarily acquired through the handling and consumption of poultry meat, discrepancies between source attribution data from case-control studies and those based on subtyping strongly suggest that transmission routes through environmental exposure may be as, if not more, important.