岩切　章・元明　秀成・山本　正悟・岩城　詩子

Infectious Agents (viruses) Surveillance Report in Miyazaki Prefecture, 2003.

Akira IWAKIRI, Hidenari GANMYO, Seigo YAMAMOTO and Utako IWAKI

Abstract
In the surveillance of infectious agents (viruses), of the total 562 samples collected from sentinel clinics and hospitals, 228 viruses were isolated in Miyazaki Prefecture in 2003.

During the 2003/04 Influenza season, 31 Influenza viruses were isolated. Of these isolates, 27 were subtyped as Influenza A (H3) viruses, and 4 were influenza B viruses, respectively. At first, Influenza A (H3) viruses were isolated toward the end of November. Subsequently, epidemics of this subtype occurred. The influenza A (H3) viruses were isolated mainly in this season , and the type B mainly in the last.

Isolation of echovirus 9 (E-9) began in March, reached the peak in June and 33 isolates were obtained. So we examined the epidemiology of E-9 infection in Miyazaki prefecture from 1991 to 2003. The relationship of clinical manifestations and age in E-9 was very clear, mean age of the Exanthema (Ex) was at 1.7±2.8 year and its of the Asepic meningitis (AM) was at 6.1±4.1 year (p<0.001). To investigate the character of E-9, we examined the nucleotide sequences encoded a part of VP1/2A region of the six isolates derived from Ex or AM and compared with other strains. It was showed that they were divided by their isolated years, and RGD motif was found in all. And it was not recognized the specific difference of the VP1/2A (nt 2951-3408) of E-9 as compared with Ex and AM.

Coxsackievirus A9 (CA9) was isolated between the middle of April and the end of August, and 38 isolates were obtained. CA9 isolates were mostly isolated from the patients with Ex, and the age of patients were 0 to 6 year (mean 1.21 year). Two epidemics of Ex causd by CA9 and E-9 occured toward spring to summer of 2003. The epidemics of earlier part was caused by E-9 and the latter part due to CA9.

An outbreak of acute haemorrhagic conjunctivitis (AHC) occured in Miyazaki prefecture. Coxsackievirus A24v (CA24v) were isolated from clinical specimens of AHC patients were successful in RD-18S and Caco-2 cells.

Coxsackievirus A16 (CA16) were mostly isolated from hand, foot and mouth disease (HFMD). HFMD is a common acute viral infection, affecting mostly young children in the summer season, Fig..1 indicates the occurrence of HFMD also from autumn to winter in this season.

Key words : influenza virus, echovirus 9, coxsackievirus A9, coxsackievirus A24v, coxsackievirus A16

はじめに
2003年11月5日に改正感染症法が施行された。主な改正点は、緊急時における感染症対策の強化（国の指示権限の創設・調整機能の役割の明確化）、動物 由来感染症の対策の強化、対象疾患および疾病分類の見直し等である。1類感染症に天然痘（痘瘡） とSARSが追加され、新4類感染症には動物由来感染症が、新５類にはバンコマイシン耐性腸球菌 （VRSA） やRespiratory syncytial (RS) ウイルス感染症等が追加された。これらの感染症発生動向調査事業については、2004年度からシステムの大幅な改正に着手することが計画されている。今後、地方公共団体における調査体制の強化が検討され、ますます感染症発生動向調査事業における病原体検出の重要性が増して来るものと思われる。

2003年のウイルス病原体検索では、562件の検体が病原体定点、協力医療機関から搬入され、228株のウイルスが分離同定、検出された。

今回、分離数の多かったインフルエンザウイルス、エコーウイルス9型、コクサッキーウイルスA9型、コクサッキーウイルスA24型変異株、およびコク サッキーウイルスA16型株について解析を行ったので報告する。なお、インフルエンザウイルスについては流行期間の関係で2003/2004シーズンにつ いて解析を行った。