ABSTRACT
<p><b>OBJECTIVE</b>To document the investigation and control of an outbreak of gastroenteritis in City G, South China, and provide a reference for preventing future outbreaks.</p><p><b>METHODS</b>An ambispective cohort study was designed. Attack rate (AR) and relative risks (RR) were calculated to identify the causes of gastroenteritis. Investigations using questionnaires included personal interviews with patients and doctors, reviews of medical records, laboratory examinations of fecal specimens and continuous hygiene monitoring of water samples from the waterworks.</p><p><b>RESULTS</b>Overall, 427/71534 (AR=5.97%) cases were identified between October 31 and November 12 2010. Geographic distribution was highly localized, with 80% of cases occurring in the areas supplied by waterworks-A. Consumption of water provided solely by waterworks-A was found to be associated with illness (RR=8.20, 95 CI%:6.12-10.99) compared with that from waterworks-B. Microbiological analyses confirmed the presence of Norovirus in six of eight fecal samples from symptomatic patients, two water samples from waterworks-A and two sewage samples. After taking effective measures, the hygienic indices of waterworks-A met health criteria again on November 9 and no cases were reported 3 days later.</p><p><b>CONCLUSION</b>The outbreak reported here was caused by drinking tap water contaminated with sewage at the source. Early identification of possible contamination sources and awareness of changes that might negatively impact water quality are important preventive measures to protect public health.</p>
Subject(s)
Adolescent , Adult , Aged , Child , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Young Adult , Disease Outbreaks , Gastroenteritis , Epidemiology , Water PollutionABSTRACT
OBJECTIVE To study the distribution and drug resistance of coagulase negative Staphylococcus(CNS)that leads to nosocomial infection.METHODS Nosocomial CNS was identified and then drug resistance test was performed by K-B method.Nitrocefin method and the Congo red method were utilized to detect ?-lactamase and the slime,respectively.RESULTS Of all 162 CNS strains isolated,there were 102 strains of MRCNS and 60 strains of MSCNS including 83 S.epidermidis strains,accounting for 51.2%.Among all the MRCNS and MSCNS strains above,the positive rates of the ?-lactamase were 100.0% and 5.0%,respectively,and the positive rates of the slime were 17.6% and 1.7%,respectively.The resistance rates of MRCNS to 12 types of antibiotics were higher than those of MSCNS(P