Purpose - An outbreak of food poisoning had occurred in Health Institute A on 1st June 2010 which involved twenty four staffs. Six of them were hospitalized and eighteen received outpatient treatment. A case control study was done to describe the epidemiological characteristics of the outbreak and to determine the source of infection.
Design/methodology/approach - Food samples, rectal swab from cases, environmental and hand swab from the food handlers were also taken and sent for microbiological analysis.
Finding- The outbreak was explosive, and the prominent clinical features were abdominal pain (62.2%), fever (51.4%), and diarrhea (56.8%). The onset time was between 9-24 hours and the median incubation period was at 15 hours. The possible source of the outbreak was durian gravy (OR= 14.00,95%CI: 2.72-92.55, p<0.001, food attack rate: 100%) and rotijala (OR= 6.69, 95%CI: LB5-24.23, p<0.001, food attack rate: 95%), The microbiological investigation revealed that various microorganisms including Salmonella spp, The food was supplied by the same food supplier from Caterer B since 2006 and the assessment of the kitchen showed that the cleanliness rate was only 54,3% with positive results of Coliform in all utensils and areas investigated in the kitchen.
Conclusion- In conclusion, the most probable causative organism based on signs and symptoms, epidemiological analysis and microbiological results was Salmonella spp. from contaminated food seryed during the ceremony. Education on food safety and food hygiene especially personal hygiene and hand washing should be emphasized continuously for prevention of future outbreak,
The following domiciliary cockroaches were collected from restaurants in five zones of Kuala Lumpur Federal Territory, Malaysia using 1L glass beaker traps baited with ground mouse-pellets: Periplaneta americana (Linnaeus) (n = 820), Periplaneta brunnea Burmeister (n = 46), Blattella germanica (Linnaeus) (n = 12504), Supella longipalpa (Fabricius) (n = 321), Symploce pallens Stephens (n = 29) and Neostylopyga rhombifolia (Stoll) (n = 5). The following bacteria were isolated from 10 cockroach specimens: Enterobacter cloacae, Klebsiella pneumoniae ssp. pneumoniae, Klebsiella pneumoniae ssp. rhinoscleromatis and Serratia liquefaciens from 5 B. germanica; Acinetobacter calcoaceticus var. anitratus, Citrobacter diversus/amalonaticus, Escherichia vulneris and K.p. pneumoniae from 3 P. brunnea; and Citrobacter freundii, Enterobacter agglomerans 4, Escherichia adecarboxylate, E. vulneris, K. p. pneumonia, K. p. rhinoscleromatis and Proteus vulgeris from 2 P. americana.
The resistance status towards permethrin among the laboratory strain, the permethrin-selected strain and four field strains of Culex quinquefasciatus collected in Kuala Lumpur, Malaysia was determined using three standard laboratory methods: WHO larval bioassay, WHO adult bioassay and biochemical microplate assay. Cx. quinquefasciatus permethrin-selected strain larvae were the least susceptible to permethrin with a resistance ratio of 47.28-folds, whereas all field strain larvae of the same species were tolerant to permethrin with resistance ratios of more than 3-folds. In contrast, in adult stage, the permethrin exposed permethrin-selected strain (resistance ratio = 1.27) was found to be more susceptible to permethrin than all permethrin-exposed field strains (resistance ratios = 2.23-2.48). Complete mortalities for all strains of Cx. quinquefasciatus adults proved the effectiveness of the synergist; piperonyl butoxide (PBO). For the biochemical microplate assay, the reduction of the mean optical density of elevated oxidase activity of three field strains upon exposure to PBO confirmed the association between oxidase activity and permethrin tolerance. On the other hand, irregular patterns of the mean optical density of elevated oxidase activity in the laboratory strain, permethrin-selected strain and Jalan Fletcher strain illustrated the gene variation within these mosquito colonies as well as the involvement of other enzyme activities in the permethrin resistance occurred.