Mechanical carrier of bacterial enteric pathogens by Chrysomya megacephala (Diptera: Calliphoridae) in Chiang Mai, Thailand
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Published on: February 13, 2015
K Sukontason1, M Bunchoo, B Khantawa
1Department of Parasitology, Faculty of Medicine, Chiang Mai University, Thailand. klikitvo@suandok01.medicine.cmu.ac.th
Abstract:
Chrysomya megacephala was studied regarding its mechanically bacterial carrier in urban areas of Chiang Mai, northern Thailand. Fifty-six adult flies were randomly collected using sweep insect net during April-May, 1999 from 3 fresh food markets and examined for bacteriological isolation. Among them, 49 flies (87.5%) were bacterial carriers. The total 22 bacterial species and 8 groups were isolated. Three species previously reported as the bacterial enteric pathogens causing diarrheal disease were isolated from 5 flies, ie Aeromonas hydrophila, Edwardsiella tarda and Vibrio cholerae non-01, with their prevalence rates in flies being 3.579, 1.79% and 3.57%, respectively. Five possible bacteria enteric pathogens, ie Aermononas sobria, Citrobacter freundii, Escherichia coli, Providencia alcalifaciens and Pseudomonas aeruginosa, were isolated from 21 flies with the prevalence rates in flies being 5.34%, 3.57%, 26.79%, 7.14% and 1.79%, respectively. The bacterial load isolated from all 3 pathogenic species was entirely found more than 10 colony per fly, indicating the high chance for disease transmission via this fly species. C. megacephala may play the possible and/or important role of bacterial enteric pathogens transmission, thereby promoting the public health personnel for sanitation improvement in fresh food markets and fly control management in these particular areas.
Insights
The study found that Chrysomya megacephala flies in Chiang Mai act as significant mechanical vectors for enteric pathogens. High bacterial loads indicate a substantial risk of disease transmission in fresh food markets.
Area of Science:
- Medical Entomology
- Public Health
- Bacteriology
Background:
- Urban environments, particularly fresh food markets, are susceptible to disease transmission.
- Flies are known mechanical vectors for various pathogens.
- Chrysomya megacephala is a common fly species in urban areas.
Purpose of the Study:
- To investigate the role of Chrysomya megacephala as a mechanical vector of bacterial enteric pathogens.
- To determine the prevalence of specific enteric pathogens carried by these flies in Chiang Mai, Thailand.
Main Methods:
- Fifty-six adult Chrysomya megacephala flies were collected from three fresh food markets.
- Flies were examined for bacteriological isolation to identify carried bacterial species.
- Prevalence rates and bacterial loads of isolated pathogens were determined.
Main Results:
- 87.5% of collected flies (49 out of 56) were identified as bacterial carriers.
- 22 bacterial species and 8 groups were isolated, including known enteric pathogens like Aeromonas hydrophila, Edwardsiella tarda, and Vibrio cholerae non-01.
- Significant prevalence rates for potential enteric pathogens such as Escherichia coli (26.79%) and high bacterial loads (>10 colonies/fly) were observed.
Conclusions:
- Chrysomya megacephala plays a significant role in the transmission of bacterial enteric pathogens in urban settings.
- Findings highlight the need for improved sanitation in fresh food markets and effective fly control measures.
- Public health interventions should consider fly control as a strategy to mitigate disease transmission risks.
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