An outbreak of viral gastroenteritis associated with consumption of sandwiches: implications for the control of transmission by food handlers.
(9/11802)
Although food handlers are often implicated as the source of infection in outbreaks of food-borne viral gastroenteritis, little is known about the timing of infectivity in relation to illness. We investigated a gastroenteritis outbreak among employees of a manufacturing company and found an association (RR = 14.1, 95% CI = 2.0-97.3) between disease and eating sandwiches prepared by 6 food handlers, 1 of whom reported gastroenteritis which had subsided 4 days earlier. Norwalk-like viruses were detected by electron microscopy or reverse transcriptase-polymerase chain reaction (RT-PCR) in stool specimens from several company employees, the sick food handler whose specimen was obtained 10 days after resolution of illness, and an asymptomatic food handler. All RT-PCR product sequences were identical, suggesting a common source of infection. These data support observations from recent volunteer studies that current recommendations to exclude food handlers from work for 48-72 h after recovery from illness may not always prevent transmission of Norwalk-like viruses because virus can be shed up to 10 days after illness or while exhibiting no symptoms. (+info)
Arbitrarily primed PCR to type Vibrio spp. pathogenic for shrimp.
(10/11802)
A molecular typing study on Vibrio strains implicated in shrimp disease outbreaks in New Caledonia and Japan was conducted by using AP-PCR (arbitrarily primed PCR). It allowed rapid identification of isolates at the genospecies level and studies of infraspecific population structures of epidemiological interest. Clusters identified within the species Vibrio penaeicida were related to their area of origin, allowing discrimination between Japanese and New Caledonian isolates, as well as between those from two different bays in New Caledonia separated by only 50 km. Other subclusters of New Caledonian V. penaeicida isolates could be identified, but it was not possible to link those differences to accurate epidemiological features. This contribution of AP-PCR to the study of vibriosis in penaeid shrimps demonstrates its high discriminating power and the relevance of the epidemiological information provided. This approach would contribute to better knowledge of the ecology of Vibrio spp. and their implication in shrimp disease in aquaculture. (+info)
Potential advantages of DNA immunization for influenza epidemic and pandemic planning.
(11/11802)
Immunization with purified DNA is a powerful technique for inducing immune responses. The concept of DNA immunization involves insertion of the gene encoding the antigen of choice into a bacterial plasmid and injection of the plasmid into the host where the antigen is expressed and where it induces humoral and cellular immunity. The most effective routes and methods for DNA immunization are bombardment with particles coated with DNA ("gene gun" technique), followed by the intramuscular and intradermal routes. DNA immunization technology has the potential to induce immunity to all antigens that can be completely encoded in DNA, which therefore include all protein, but not carbohydrate, antigens. DNA immunization results in presentation of antigens to the host's immune system in a natural form, like that achieved with live-attenuated vaccines. The DNA immunization strategy has the potential to rapidly provide a new vaccine in the face of an emerging influenza pandemic. (+info)
Evaluation of clinical case definitions of influenza: detailed investigation of patients during the 1995-1996 epidemic in France.
(12/11802)
Using clinical predictors, we evaluated clinical case definitions of influenza during the 1995-1996 outbreak in France. Thirty-five general practitioners collected virological specimens and clinical data. Predictors of influenza virus infection were selected with logistic regression models. The results varied with the influenza virus subtype: temperature of >38.2 degrees C, stiffness or myalgia, rhinorrhea, and cough were predictive of influenza A/H3N2, whereas fatigue, lacrimation or conjunctival injection, and the absence of stiffness or myalgia were predictive of influenza A/H1N1. On the basis of this analysis and data from the literature, 12 clinical case definitions were evaluated for their abilities to diagnose influenza virus infection. They were associated with positive predictive values of 27% to 40% and negative predictive values of 80% to 91%. We conclude that focused studies evaluating clinical case definitions of influenza with use of subsets of patients should accompany population-based disease surveillance for optimal estimates of the disease burden associated with influenza epidemics. (+info)
Observations on animal and human health during the outbreak of Mycobacterium bovis in game farm wapiti in Alberta.
(13/11802)
This report describes and discusses the history, clinical, pathologic, epidemiologic, and human health aspects of an outbreak of Mycobacterium bovis infection in domestic wapiti in Alberta between 1990 and 1993, shortly after legislative changes allowing game farming. The extent and seriousness of the outbreak of M. bovis in wapiti in Alberta was not fully known at its onset. The clinical findings in the first recognized infected wapiti are presented and the postmortem records for the herd in which the animal resided are summarized. Epidemiologic findings from the subsequent field investigation are reviewed, the results of recognition and investigation of human exposure are updated, and recommendations for reduction of human exposure are presented. (+info)
Bacterial pneumonia as a suprainfection in young adults with measles.
(14/11802)
The aim of this study was to report the clinical and laboratory characteristics of bacterial pneumonia related to measles infection, and also to assess any correlation between severity and time of onset. Four hundred and twenty-four previously healthy young males (age 22+/-2.1 yrs) were hospitalized with typical symptoms and signs of measles. One hundred and twelve (26%) developed bacterial pneumonia on admission (n=41), during their hospital stay (n=20) or days after their discharge (n=51): groups A, B and C, respectively. Single lobar consolidation was the most common finding, accounting for 89% of cases. Pleural effusion was uncommon and associated in half of the cases with empyema. A microbiological diagnosis was made in 81 cases. Streptococcus pneumoniae (65 cases) and Klebsiella pneumoniae (9 cases) were the most commonly identified organisms. Patients from group C had significantly higher values of white blood cell count and erythrocyte sedimentation rate, and lower values of arterial oxygen tension (14+/-0.8 x 10(9) x L(-1), 88+/-4 mm and 6.3+/-0.4 kPa (47+/-3 mmHg), respectively) than the other two groups. There were no deaths during the hospitalization period. The mean duration of hospital stay was 13+/-2.4 days and was longer in the presence of K. pneumoniae infection (19+/-1.6 days). Six patients from group C were admitted to the intensive care unit. In conclusion, these data suggest that bacterial pneumonia associated with measles is not unusual in hospitalized adults, and it seems to be more severe when it occurs days after the onset of rash. (+info)
Application of nested polymerase chain reaction to detection of mouse hepatitis virus in fecal specimens during a natural outbreak in an immunodeficient mouse colony.
(15/11802)
The usefulness of RT-PCR for the detection of MHV in tissues and feces of experimentally infected animals has been reported, but it was unclear whether the method was also applicable for the detection of MHV during a natural outbreak. Enterotropic infection is considered to be the most common form of natural infection among various forms of MHV infection. In this paper, RT-nested PCR was performed to detect MHV excreted in the feces during an outbreak in an immunocompromised A/WySnJ mouse colony. The expected bands were amplified after nested PCR from 20 fecal samples out of 37. These results showed that RT-nested PCR could be applicable for the diagnosis for MHV natural infection. (+info)
Transmission of epidemic Vibrio cholerae O1 in rural western Kenya associated with drinking water from Lake Victoria: an environmental reservoir for cholera?
(16/11802)
Sub-Saharan Africa has the highest reported cholera incidence and mortality rates in the world. In 1997, a cholera epidemic occurred in western Kenya. Between June 1997 and March 1998, 14,275 cholera admissions to hospitals in Nyanza Province in western Kenya were reported. There were 547 deaths (case fatality rate = 4%). Of 31 Vibrio cholerae O1 isolates tested, all but one were sensitive to tetracycline. We performed a case-control study among 61 cholera patients and age-, sex-, and clinic-matched controls. Multivariate analysis showed that risk factors for cholera were drinking water from Lake Victoria or from a stream, sharing food with a person with watery diarrhea, and attending funeral feasts. Compared with other diarrheal pathogens, cholera was more common among persons living in a village bordering Lake Victoria. Cholera has become an important public health concern in western Kenya, and may become an endemic pathogen in the region. (+info)