Risk Factors of a Chikungunya Outbreak in Bali, Indonesia 2022
- Vector-borne
Background
On January 2022, authorities in Tabanan district reported a case of joint pain with paraplegy, and other cases with fever, rash and joint pain. The health center took blood samples from 15 cases, five of which were confirmed as Chikungunya infection. We conducted an epidemiological investigation to find additional cases and assess risk factors to the outbreak.
Methods
A field investigation were performed in Tabanan district during Jan-Feb 2022 to look for additional cases. No lab examination was conducted for potential additional cases. A case-control (1:1) study was conducted. Cases (42) were defined as those who confirmed by laboratory and those with symptoms (fever or joint pain and rash), controls (42) were who did not have any symptoms in the same village and were matched based on gender and age. Data were collected using questionnaires. Data were analyzed by uni, bi, and multivariate logistic regression.
Results
Cases were found in 3 of 8 sub-villages. The overall AR in one month was 0,70% with a peak in the 2nd week. AR of males (0,73%) was higher than females (0,66%), AR of adult age (1,32%) was higher than non-adults (1,07%). The main symptoms were fever (97,6%), joint pain (88,1%), headache (73,8%) and rash (54,8%). Factors associated with cases were: Not using mosquito repellent, did not eliminate mosquito habitats, habit of hanging clothes and presence of mosquito larvae in environment had a p-value<0,05. Logistic regression analysis using Backward method found: did not eliminate mosquito habitats (OR=5,39, 95%CI=1.415-20,533), not using mosquito repellent (OR=5,61, 95%CI=1.581-19,870) and found mosquito larvae (OR=10,98, 95%CI=2.930-41.143) were significant as risk factors for the outbreak.
Conclusion
The Chikungunya outbreak was caused by behavioral and environmental factors. Elimination of mosquito habits in and around the house through the synergies of the community, government, and health workers must be improved.
On January 2022, authorities in Tabanan district reported a case of joint pain with paraplegy, and other cases with fever, rash and joint pain. The health center took blood samples from 15 cases, five of which were confirmed as Chikungunya infection. We conducted an epidemiological investigation to find additional cases and assess risk factors to the outbreak.
Methods
A field investigation were performed in Tabanan district during Jan-Feb 2022 to look for additional cases. No lab examination was conducted for potential additional cases. A case-control (1:1) study was conducted. Cases (42) were defined as those who confirmed by laboratory and those with symptoms (fever or joint pain and rash), controls (42) were who did not have any symptoms in the same village and were matched based on gender and age. Data were collected using questionnaires. Data were analyzed by uni, bi, and multivariate logistic regression.
Results
Cases were found in 3 of 8 sub-villages. The overall AR in one month was 0,70% with a peak in the 2nd week. AR of males (0,73%) was higher than females (0,66%), AR of adult age (1,32%) was higher than non-adults (1,07%). The main symptoms were fever (97,6%), joint pain (88,1%), headache (73,8%) and rash (54,8%). Factors associated with cases were: Not using mosquito repellent, did not eliminate mosquito habitats, habit of hanging clothes and presence of mosquito larvae in environment had a p-value<0,05. Logistic regression analysis using Backward method found: did not eliminate mosquito habitats (OR=5,39, 95%CI=1.415-20,533), not using mosquito repellent (OR=5,61, 95%CI=1.581-19,870) and found mosquito larvae (OR=10,98, 95%CI=2.930-41.143) were significant as risk factors for the outbreak.
Conclusion
The Chikungunya outbreak was caused by behavioral and environmental factors. Elimination of mosquito habits in and around the house through the synergies of the community, government, and health workers must be improved.