An investigation of Hepatitis A outbreak in Village 6 Ban Maeplu, Maeousu Subdistrict, Tha Song Yang District, Tak Province, Thailand, 24–26 April 2014

Abstract

Background: On 2014 April 22nd, the division of Epidemiology, Department of Disease Control was notified from Tak Provincial Health Office about three suspected Hepatitis A infection cases in Maeousu Subdistrict, Tha Song Yang district, Tak province. Then we conducted an outbreak investigation to confirm the diagnosis and the outbreak, to identify the source of infection, to know the immunity level in the communities and to recommend the control measures.
Methods: The descriptive study was conducted. By reviewing medical records and finding the active case in the community using the case definitions developed by Division of Epidemiology. We conducted serological survey in order to compare the infected rate as well as the immunity rate between ‘area no. 6 of Mae-Plu village, Maeousu Subdistrict, Tha Song Yang district’ and ‘Mueng district, Tak province’. We collected the specimens for laboratory testing by the criteria. The environmental survey was also conducted. The water samples from various site were collected for RT-PCR.
Results: During April-May 2014, the outbreak of Hepatitis A virus was occurred in village 6 Ban Maeplu, Maeousu Subdistrict, Tha Song Yang district, Tak province. We found totally 5 patients and 7 asymptomatic cases who lived in the same house and had closely contacted with each other. The risk for disease exposure were such as Handle the glass to draw water from the container directly, Using the shared glass, Drinking unboiled water, Closely contact with each other and Improper personal hygiene. For serological survey, age group 0-6 and 7-14 years of Mueng district showed no immunity to Hepatitis A virus while village 6 Ban Maeplu showed 21.43 and 57.14 percent of immunity rate, respectively. The statistical analysis showed the difference between two communities significantly in age group 0-14 and 15-24 years. For water samples testing, we could not found any genetic material of Hepatitis A virus. The source of the outbreak could not be identified but the most suspect source was the water from the canal behind the village. The environmental survey also showed the sanitation was inappropriate.
Recommendation: Give health education to the community in order to change the health behavior in the proper way. Improve the sanitation of the village by fallowing the standard criteria. Conduct the surveillance for Hepatitis A virus in the village for at least 2 months.