[Evaluation of the flu call center and medical system data on pandemic (H1N1) 2009 influenza. Comparison of cases in Kobe city and Ibaraki prefecture].

OBJECTIVES: To make recommendations on the revision of the Pandemic Influenza National Action Plan and Guidelines, we reviewed the data from the flu call center and medical institutions in Kobe city and compared them with data from Ibaraki prefecture.

METHODS: The overall duration of study from May 2009 to December 2009 was divided into 4 periods; we analyzed details of the calls received by the call center and examined the correlation between them and cases who were seen at medical institutions in Kobe. We used a mathematical model to approximate the cumulative growth curve of the number of calls received by the call center and the number of cases attending fever clinics in Kobe. We compared the above data with data from Ibaraki because the total number of confirmed cases of pandemic (H1N1) 2009 influenza was similar: Kobe identified the first confirmed case of the influenza in Japan, while Ibaraki reported their first case 1 month later.

RESULTS: Following the report of the initial domestic case, the Kobe call center received 30,067 calls in a month. A "delayed sigmoid curve" fitted well for both the rise in the number of calls at the call center and of cases attending the fever clinics. "Feeling sick despite no overseas travel history" was the most common reason for call. More than 2,000 calls/day were received, and the responses to such calls were instructions to consult a general medical institution (40%), instructions to refer to a fever clinic (8%), guidance on home care or how to manage underlying disorders, and listening to callers' anxieties and complaints. The numbers of calls decreased towards the end ofJuly; the number of calls increased again when outbreaks were reported in schools and a death due to influenza was confirmed. After November, on an average, 500 calls/day were received; most were complaints regarding vaccination. Unlike Kobe, Ibaraki did not experience a surge in the number of calls to the call center or consultations to fever clinics within a short period of time.

CONCLUSION: The outbreak of pandemic (H1N1) 2009 influenza showed different call patterns and medical consultations in different regions. The time of disease outbreak and the availability of medical resources differ among regions; hence, each municipality should act practically and flexibly according to the situation in their locality.