Analysis of three family clusters of severe fever with thrombocytopenia syndrome by exposure risk matrix / 预防医学

ABSTRACT

Objective@#To analyze three events of severe fever with thrombocytopenia syndrome （SFTS） among family members by exposure risk matrix, so as to provide reference for SFTS prevention and control.@*Methods @#The field investigation and clinical data of seven confirmed cases with SFTS reported in Linhai from 2014 to 2016 were collected. Exposure risk matrix was used to list the risk of exposure two weeks before the onset, such as the environment, duration of activity and protection, and evaluate the possible routes of transmission. @*Results@#The first event involved three sisters. Two of them had plucked tea together on a hill, and the possibility of infection through tick bites were 60% and 75%, respectively. Another sister was more likely to be infected by ticks in her residence after visiting her sister （no physical contact with the sick sister）, with a possibility of 74%. The second event involved two cases （mother and son）. They were more likely to be infected by ticks in the current residential area, and the possibility were 100% and 80%, respectively. The third event involved two cases （husband and wife）. The wife had 60% possibility of being infected by the ticks on the hill she picked arbutus, and 40% by the ticks in her residence. The husband was most likely to be infected through contacting with body fluids or blood of his wife （44%）, then through the ticks on the hill he picked arbutus （33%）. @*Conclusion@#Among seven cases with SFTS reported in Linhai from 2014 to 2016, six cases have more than 50% possibility of being infected by tick bites; one case has higher possibility of being infected by contacting with body fluids or blood of a patient, but tick bites could not be ruled out.