Yutaka Arimoto

Protection Against Pertussis by Acellular Pertussis Vaccines (Takeda, Japan): Household Contact Studies in Kawasaki City, Japan

To evaluate the vaccine efficacy of an acellular pertussis vaccine which has been in clinical use in Japan since 1981, a retrospective study was performed by a questionnaire survey of secondary pertussis attacks through family contact in 146 children with pertussis diagnosed in the period from January 1981 through May 1988. In this study, acellular vaccine made by Takeda Pharmaceutical Company, which contains a high level of FHA (filamentous hemag‐glutinin), a low level of PT (pertussis toxin) and a small amount of agglutinogen, was evaluated. Secondary pertussis attacks through family contact were found in 17 of 29 siblings (58.6%) not immunized with pertussis vaccine. On the other hand, 27 siblings immunized with Takedas acellular vaccine were exposed to pertussis through family contact and a secondary attack was seen in only one of them (3.7%). The present study revealed an efficacy rate of 93.7% for Takedas acellular pertussis vaccine.

Relation between serum hepatitis C virus‐RNA levels and efficacy of interferon‐β therapy

We performed two courses of interferon‐β (IFN‐β) to a child with chronic hepatitis C. A complete response was not obtained by the first interferon treatment, however, the results of the second treatment differed from those of the first. Hepatitis C virus (HCV)‐RNA remained negative and both aspartate aminotransferase and alanine aminotransferase levels remained normal after completion of the second course. From these results we estimated that HCV‐RNA levels before IFN therapy could be significantly associated with the efficacy of this treatment. The serum level of HCV‐RNA was 106 copies/50 μL before the first treatment, but was 103 copies/50 μL before the second course.

静岡県東部地域における平成7年手足口病患児のCoxsackie Virus A16のVP4領域の塩基配列についての検討

In 1995 an investigation was made for VP4 regions of coxsackie virus A16 (CA16) RNA sequence from hand-foot-mouth disease patients in eastern district of Shizuoka Prefecture. Subjects were seven patients who were diagnosed as hand-foot-mouth disease due to CA16 at the Ohashi Pediatric Clinic in Susono City. Throat swabs of patients were extracted to RNA. Extracted RNA were assayed by reverse transcription polymerase chain reaction that primers corresponded to VP4 resion of enteroviruses. PCR products were marked by dye-deoxy terminator methods and assayed by direct sequence methods. RNA sequences were classified into two types. Type 1 were three cases, and type 2 were four. The homology was 90.8% between type 1 and type 2. All cases of sixty-nine amino acids were the same as prototype strain. We concluded that the two type strains of CA16 were prevalented in eastern district of Shizuoka Prefecture in 1995. It was at the same time and was widely noted in the eastern district.