The Tohoku Journal of Experimental Medicine. Vol. 71, No. 1, 1959 Outbreaks of Aseptic Meningitis Caused by HVJ (Influenza D) Tooru By Nakao From the Department of Pediatrics, Aomori Prefectural Central Hospital ; Pediatrician-in-Chief: Dr. T. Na k a o and Morihide Yamada From the Department of Bacteriology, Faculty of Medicine, Hokkaido University, Sapporo; Director : Prof. M. Tam a d a (Received for publication, July 30, 1959) Due to the advance of virology, it has been shown that aseptic menin gitis can be caused by various viruses. In Aomori City and its neighborhood, outbreaks of aseptic meningitis have been seen every year since 1954 in children mostly during summer. In 1954 and 1955, we were able to isolate viruses from cerebrospinal fluid, blood and throat washings from patients with aseptic meninigtis. In 1952, Sano1) and Kuroya2) isolated a new virus from the lungs of newborn pneumonitis. This virus was later named HVJ (Hemaggluti natining Virus of Japan), Sendai Virus or Influenza D.3) The virus we had isolated from the above-mentioned cases of aseptic meningitis was identified as HVJ. In the present paper we shall report mainly clinical observation of 125 cases of aseptic menigitis due to HVJ that we experienced in the Aomori area from 1954 to 1956. Clinical Features Incidence. As is given in Table I, aseptic meningitis occurred in the season from June to October, but in 1955 and 1956 the outbreak was seen all the year round. Age and Sex. As is given in Table U, most patients were under ten years, and there were more males than females. Symptoms and Signs The onset was abrupt in all the cases. Symptoms and signs were summarized in Table V. Fever, nausea, vomiting and headache were outstanding symptoms. Fever was always present except in a case. Dura- 61
62 T. Nakao and M. Yamada TABLE T Seasonal Incidence of Aseptic Meningitis in 125 Cases from 1954 to 1956 TABLE U Age and Sex of 125 Cases of Aseptic Meningitis TABLE V Symptoms and Signs of 125 Cases of Aseptic Meningitis tion of fever was short in most cases as will be seen from Table W. Laboratory Findings Cerebrospinal fluid In an early stage of illness, lumbar puncture was performed. Fluid was clear or slightly turbid. Pressure was high in most cases. Pleocytosis
Outbreaks of Aseptic Meningitis Caused by HVJ (Influenza D) 63 TABLE W Duration of Fever in 125 Cases of Aseptic Meningitis TABLE X Cell Counts of Cerebrospinal Fluid in 125 Cases of Aseptic Meningitis was seen in all the cases as is given in Table V, and mononuclear cells predominanted. Globulin reactions were negative or slightly positive. Sugar levels were within normal ranges. After several days from the onset of disease clinical symptoms began to subside, nevertheless pleocytosis remained to persist for from two to four weeks. Blood picture Red cell counts and hemoglobin levels were within normal ranges. White cell counts were either normal or slightly increased, eosinophiles were either decreased or disappeared in early stage of illness. Red sedi mentation rates were slightly accelerated in early stage.
64 T. Nakao and M. Yamads Course Prognosis was good and no unfavourable sequels were seen, but in 1955, only a case, a boy of 2 years and 5 months, died of complicated en cephalitis. Virus study. Details of the virological investigation will be reported in a coming issue of this Journal4). In early stage of illness viruses were isolated from cerebrospinal fluid, blood and throat washings of the patients. In 1954, ten strains from four patients were isolated both by nasal instillation of materials to mouse and by chicken embryo inoculation. In 1955, five strains from three patients were isolated only by means of inoculation of materials to embryonated eggs. These strains were serologically identified as HVJ. In most cases hemagglutination and complement fixation titers became much higher in the reconvalescent of disease than in the acute (cf. Table mothers Y). Non-manifest infections were demonstrated in some of the patients' serologically. TABLE Y Hemagglutination Titers of Sera from Patients with Aseptic Meningitis As has been stated above, one of our own cases was fatal. In this case, the viruses which were isolated on the 8th day of disease from his cerebrospinal fluid and blood and on the 7th day from his cerebrospinal fluid were identified as HVJ. SUMMARY AND CONCLUSIONS Clinical observation of 125 cases with aseptic meningitis in Aomori City and its neighborhood was described. From cerebrospinal fluid, blood and throat washings of patients, viruses were isolated, which were identi fied as HVJ (Influenza D). Clinical features and laboratory findings of these cases were not es sentially different from those of meningitis cases caused by other kinds of virus.
Outbreaks of Aseptic Meningitis Caused by HVJ (Influenza D) 65 References 1) Sano, Niitsu, Nakagawa and Ando, Yokohama Medical Bull, 1953, 4, 199. 2) Kuroya, Ishida and Shiratori, ibid., 1953, 4, 217. 3) Jensen, Mirucse and Ackermann, J. Immunol, 1955, 75, 71. 4) Yamada, Sagae, Arie, Ochi, Nakao and Ichihashi, Aseptic Meningitis of Infants and Children Caused by " Hemagglutinating Virus of Japan " (HVJ). To be published in this Journal.