Mikio Minamitani

HIGH INCIDENCE OF BREAKTHROUGH VARICELLA OBSERVED IN HEALTHY JAPANESE CHILDREN IMMUNIZED WITH LIVE ATTENUATED VARICELLA VACCINE (OKA STRAIN)

In order to know the rate of occurrence of varicella among vaccinees (breakthrough varicella: BV), questionnaire postcards were sent to 593 healthy children who had received varicella vaccine (Oka strain) from March 1987 to December 1989. The questionnaire survey was repeated once a year until January 1996. The annual attack rate from the 1st to 3rd questionnaire was approximately 12%; however, from the 5th to 8th one it was 1–4%. To February 1996, the cumulative attack rate was 157/459 (34.2%). This rate was comparable to that among vaccinees who had confirmed seroconversion; namely, 51/132 (38.6%). These rates are much higher than those reported by other authors. All BV cases were clinically mild; even subjects who had received the vaccine 7 years prior to the disease showed mild symptoms. The high incidence may be partly explained by the regional epidemiology of varicella. The decrease in annual incidence with time after vaccination may be due to the following reasons: some vaccinees remained free from BV owing to reinforcement of their immunity from subclinical infection of varicella‐zoster virus (VZV) and others from diminution of opportunity for exposure to VZV with increasing age. Varicella vaccine seems to be effective in modifying the symptoms of varicella, but not potent enough in protecting from VZV infection.

Presence of multiple HIV type 1 subtypes among mothers and children in Japan.

We collected blood samples from 70 HIV-1-infected pregnant women and 76 babies born to HIV-1-infected women in Japan, from 1989 to 1999. To analyze the genetic diversity of HIV-1 among mothers and children, we sequenced the C2-V3 regions of HIV-1 gp120. Phylogenetic tree analysis of these regions revealed that multiple HIV-1 subtypes, A, B, D, E, and G, were circulating among mothers and children in Japan. Thus, the genetic heterogeneity of HIV-1 among mothers and children in Japan is steadily increasing, although the number of cases remains small. Perhaps the longest term survivor, an 11-year-old child with a vertical HIV-1 subtype G infection in Japan, is one of our subjects.

成人水痘入院症例の検討: 臨床像, 重症度, 感染経路および合併症

Varicella has been thought to be one of the representative infectious disease in childhood, but recently we are under the impression that adults contracting varicella are increasing in number. On the other hand, they say that varicella generally causes a serious illness in adult patients. So we investigated signs and symptoms of varicella, source of infection, occupations of adult patients, except those who were immunologically compromised, by means of medical records, to know the characteristics of varicella in adulthood. According to the varicella severity score proposed by Nagai et al., varicella in the hospitalized adult patient was found to be much severer than that in children. The most remarkable symptoms, were high fever and sore throat, and these were the main reason of hospitalization in most of our patients. Although severity scores were very high in admitted adult patients with varicella, their clinical courses were not serious, and most of them recovered with only supportive therapy. These patients rarely suffered from complications, like pneumonia. If adult patients with varicella hospitalized in the early stage and received supportive care, they could recover without any complications. In most cases of adult varicella the source of infection was unknown. In the case of married persons, however, many of them were infected through their child. When adults contract varicella, not only the patients themselves suffer from high fever and sore throat, but also they act as the source of infection, if they are medical care workers. Furthermore, in public, the contraction of varicella results a socioeconomic loss from suspension of business caused by the illness. Prophylaxis with varicella vaccine, therefore, should be considered, when there are people who have never contracted varicella, whether or not they are medical staff.

Vertical infection of human immunodeficiency virus as an imported infectious disease

Abstract Background and methods: In Japan, 26 children who vertically acquired human immunodeficiency virus (HIV) infection had been reported as at February 1997. Little information was published about their epidemiological backgrounds and the rate of perinatal HIV transmission in Japan remains unknown. To learn the epidemiological features of perinatal HIV infection in Japan, we examined the medical records of five perinatally infected children.

The Present State of Bacterial Diarrheal Diseases in Japan and Their Chemotherapy

Acute diarrhea is one of the most frequently encountered diseases, next only to respiratory infection, in the routine medical care at the pediatric department. And most cases of this disease are caused by digestive tract infections. As the causes of digestive tract infections, Shigella, Salmonella, Vibrio and enteropathogenic E. coli have long been recognized for tfieir pathogenicity and have been regarded as the typical pathogens. It has become clear today, however, that most of the infantile acute diarrheal cases are due to viruses, the frequency of bacterial digestive tract infection in infants being much lower than in adult patients. While Table 1 shows the pathogenic organisms for acute diarrhea, the rate of isolation of pathogens from the feces of the infantile acute diarrhea patients ranges between 10-30% and there are not a few reports [ 1-61 which have put it at less than 10%. Since culture of the rotavirus became easier [ 6 ] , its importance as a cause of diarrhea has been brought to light. At the same time, other pathogenic viruses have been studied, and it has been confirmed today that viruses are playing a leading part in the causation of diarrhea.

Application of a Live Varicella Vaccine to the Immunosuppressive Children and the Incibence of a Case of Herpes Zoster after Vaccination

A live varicella vaccine was applied to 13 susceptible children to varicella virus. Three were receiving steroid therapy, and one of them was treated with both steroid and anticancer drugs. Immunosuppressive therapy and anticancer medication were not suspended before and after vaccination. Serological responses were observed in 11 of 13 vaccinated children by fluorescent antibody to membrane antigen (FAMA) test 6 to 7 weeks after Vaccination. Mild rash appeared as only a clinical reaction in 3 of the vaccinated children. However, 3 and a half months later, a vaccinee with acute myeloblastic leukemia, developed herpes zoster. Our observation suggested a possibility of contracting zoster in immune compromised hosts after vaccination with a live varicella vaccine.