Salmonella in the Caribbean case study was undertaken by the Caribbean Epidemiology Centre (CAREC). Salmonella bacterial infections are very common food borne infections that cause acute gastroenteritis, often resulting in outbreaks (Centres for disease control and prevention (CDC), 2014).
In the case study, salmonellosis was characterized in terms of location, most affected gender, and seasonality in Trinidad and Tobago. The occurrence of salmonellosis was examined through descriptive epidemiology of the cases. The annual incidence rates of confirmed laboratory salmonella infections cases were calculated from 1988 to 1997.For example in 1997; there were 109 reported salmonellosis cases. The annual incidence rate per 100,000 populations was obtained by dividing number of cases (109) by estimated population per year (1,265,000) to get 8.6 cases per 100,000 populations. This laboratory confirmed salmonella infections did not give a true burden of salmonellosis that is cases not detected and those detected but unreported in 1997.A line graph showing laboratory confirmed slamonellosis by year of diagnosis was plotted and indicated a continuing increase in salmonella infections between 1988 and 1997.This was due to improved disease surveillance systems and high laboratory specimen testing. Multiple line graphs was plotted to show the various serotype of salmonellosis and year of diagnosis. From 1995 to 1997, there was an increase in salmonella enteritidis infections to a total of 227 laboratory confirmed cases. There were 75 sporadic cases yearly except for one that was point source outbreak .This affected 48% male and 52 % females with the highest incidence rates being among those below four years. This was because children with gastroenteritis are most likely taken to hospital for laboratory specimen investigations and due to their high risk for exposure. Moreover, these cases were more in December and January from 1995 to 1997 despite the climate being warm throughout. Identification of the source of the infections was needed. Therefore risk factors were explored through conducting a case control study. 45 case patients, those with laboratory confirmed enteritidis and 92 controls were asked about exposures to likely salmonella sources in food, beverages, animal contact, water sources and history of travel in 3 days. To measure association, odds ratio for exposure to potential salmonella sources was calculated with p value of 0.05.differnnces in exposure to likely salmonella sources was noted between the cases and controls . Results showed eating shell eggs, dishes containing raw eggs and underlying illnesses as risk factors with an odds ratio of more than 1.0 and significantly associated with the infections. Protective factors with odds ratio of less than 1.0 included buying refrigerated eggs and refrigerating the at home. Foods containing eggs were mostly taken during holidays thus explain the reasons for increase in salmonella enteritidis in December and January.
Delegate your assignment to our experts and they will do the rest.
The case control study carried out had selection, recall and information bias. The section of the controls is not representative of the population that gave the cases that’s the selection of 45 cases compared to 92 controls. Recall bias especially on the foods eaten and information bias when getting the information from the parent or guardian for those aged below for years. The finding of the association between raw egg/ egg shell consumption and salmonella enteritidis may not be generalized for other population that do not consume eggs. The study began in March 1998 to May 1999.This long duration would likely result to high participant attrition thus affecting the accuracy of the study finding.
I have learned that bio statistical methods helps one to handle a public health concern. This is by quantifying the disease burden and identifying the source of infections or risk factors through case control studies so that one can put in place various control and preventive measures.
References
Centres for disease control and prevention (CDC). (2014). Salmonella in the Caribbean. Retrieved from http://www.cdc.gov/training/SIC_CaseStudy/page2.htm
