Occurrence of Escherichia coli O157 in a river used for fresh produce irrigation in Nigeria

Concerns about the persistence of Escherichia coli O157 in irrigation waters and its transmission to fresh produce makes investigation of irrigation waters imperative. The prevalence of this pathogen and seasonal levels of water quality parameters in Kubanni River were studied, using standard methods, over a 10-month period. Detection rate for E. coli O157 confirmed by slide agglutination was 2.1%. Faecal coliform counts (FCC) exceeded acceptable limits and was significantly higher in the dry season than during the rainy season (p<0.05). Remarkably, nitrate level was significantly higher in the rainy season than dry season (p<0.05). A significant (p<0.05) correlation was established between FCC and each of nitrate (r = 0.25), biochemical oxygen demand (r = 0.51) and electrical conductivity (r = 0.55). It was concluded that the Kubanni River represents a potential public health risk, being unfit for fresh produce irrigation. Perhaps, this is the first report on the isolation of E. coli O157 from water sources in Nigeria

Intestinal parasitosis and shigellosis among diarrheal patients in Gondar teaching hospital, northwest Ethiopia

<p>Abstract</p> <p>Background</p> <p>Diarrheal diseases are the major causes of morbidity and mortality in developing world. Understanding the etiologic agents of diarrheal diseases and their association with socio-demographic characteristics of patients would help to design better preventive measures. Thus, this study was aimed to determine the prevalence of intestinal parasites and enteropathogenic bacteria in diarrheic patients.</p> <p>Methods</p> <p>A cross-sectional study involving 384 consecutive diarrheal patients who visited Gondar teaching hospital, Gondar, Ethiopia from October 2006 to March 2007 was conducted. Stool specimens were collected and examined for intestinal parasites and enteropathogenic bacteria following standard parasitological and microbiological procedures.</p> <p><b><it>Results</it></b></p> <p>Intestinal parasites were diagnosed in 36.5% of the patients. The most frequently encountered protozoan parasite was <it>Entamoeba histolytica/dispar </it>(7.3%) followed by <it>Giardia lamblia </it>(5.0%), C<it>ryptosporidium parvum </it>(1.8%) and <it>Isospora belli </it>(1.3%). The dominant helminthic parasite identified was <it>Ascaris lumbricoides </it>(5.5%) followed by <it>Strongyloides stercoralis </it>and <it>Schistosoma mansoni </it>(3.1% each), hookworm infection (1.8%), and <it>Hymenolepis </it>species (1.3%). Multiple infections of intestinal parasites were also observed in 6.3% of the patients. Among the enteropathogenic bacteria <it>Shigella </it>and <it>Salmonella </it>species were isolated from 15.6% and 1.6%, respectively, of the patients. <it>Escherichia coli O57:H7 </it>was not found in any of the stool samples tested. Eighty eight percent and 83.3% of the <it>Shigella </it>and <it>Salmonella </it>isolates were resistant to one or more commonly used antibiotics, respectively.</p> <p>Intestinal parasitosis was higher in patients who live in rural area, in patients who were washing their hands after visiting toilet either irregularly with soap and without soap or not at all, in patients who used well and spring water for household consumption, and in patients who had nausea (<it>P </it>< 0.05). Statistically significant associations were also observed between Shigella infections and patients who were using well and spring water for household consumption, and patients who had dysentery and mucoid stool (<it>P </it>< 0.05).</p> <p>Conclusions</p> <p>The high prevalence of intestinal parasites and <it>Shigella </it>species in diarrheic patients calls for institution of appropriate public health intervention measures to reduce morbidity and mortality associated with these diseases. The rational use of antibiotics should also be practiced.</p

Surface water chemistry and nitrate pollution in Shimabara, Nagasaki, Japan

Groundwater is a finite resource that is threatened by pollution all over the world. Shimabara City, Nagasaki, Japan, uses groundwater for its main water supply. During recent years, the city has experienced severe nitrate pollution in its groundwater. For better understanding of origin and impact of the pollution, chemical effects and surface?groundwater interactions need to be examined. For this purpose, we developed a methodology that builds on joint geochemical analyses and advanced statistical treatment. Water samples were collected at 42 sampling points in Shimabara including a part of Unzen City. Spatial distribution of water chemistry constituents was assessed by describing Stiff and Piper diagrams using major ions concentrations. The nitrate (NO3 + NO2?N) concentration in 45% of water samples exceeded permissible Japanese drinking level of 10 mg L? 1. Most of the samples showed Ca?HCO3 or Ca?(NO3 + SO4) water types. Some samples were classified into characteristic water types such as Na?Cl, (Na + K)?HCO3, (Na + K)?(SO4 + NO3), and Ca?Cl. Thus, results indicated salt water intrusion from the sea and anthropogenic pollution. At the upstream of Nishi River, although water chemistry was characterized as Ca?HCO3, ion concentrations were higher than those of other rivers. This is probably an effect of disinfection in livestock farming using slaked lime. Positive correlation between NO3 ? and SO4 2?, Mg2+, Ca2+, Na+, K+, and Cl? (r = 0.32?0.64) is evidence that nitrate pollution sources are chemical fertilizers and livestock waste. Principal component analysis showed that chemistry of water samples can be explained by three main components (PCs). PC1 depicts general ion concentration. PC2 and PC3 share influence from chemical fertilizer and livestock waste. Cluster analyses grouped water samples into four main clusters. One of these is the general river chemistry mainly affected by PC1. The others reflect anthropogenic activities and are identified by the combination of the three PCs