Therapeutic effect of clarithromycin for respiratory-tract infections in children caused by Chlamydia pneumoniae. Research Group of Sapporo for Pediatric Chlamydial Infections.

Children infected with Chlamydia pneumoniae sometimes experience lower respiratory tract infections such as pneumonia and bronchitis. Although numerous anti-microbial compounds have been reported to be active against the organism, most of them have not been in a clinical trial in infants and children with C. pneumoniae infection. Clarithromycin has been shown to express anti-chlamydial effects in vitro. In this study, we evaluated the clinical anti-C. pneumoniae properties of clarithromycin in children with mainly lower respiratory tract infection. We administered clarithromycin orally to 21 infants and children at a dose of 10-15 mg/kg/day divided into two or three doses for 4-21 days. Clinical symptoms, roentgenographic and laboratory abnormal findings improved. The overall clinical efficacy rate was 85.7% (18 of 21 cases). Administration of clarithromycin was considered to be a suitable treatment for improving lower respiratory infections in infants and children caused by C. pneumoniae.

Mitral regurgitation with gross deformity of a mitral leaflet due to Kawasaki disease.

A 4-year-old girl had two episodes of Kawasaki disease which resulted in severe mitral regurgitation. She had not had any coronary arterial lesion during the acute phase of the illness, nor any myocardial ischemia. Severe destruction of the mitral leaflet was documented by two-dimensional echocardiography. It is suggested that this lesion was due to severe carditis and valvulitis which developed during the acute phase of the illness.

Terminal deletion of chromosome 10q and its clinical features.

A male case with terminal deletion of chromosome 10q has growth retardation, craniofacial dysmorphism, congenital heart disease and other minor anomalies. The karyotypic formula is 46, XY, del (10), (q26.1----qter) by a high resolution G-banding staining. There are few differences in clinical features between our case and the previously reported cases.

Microtiter solid-phase radioimmunoassay for detection of human calicivirus in stools.

A microtiter solid-phase radioimmunoassay (RIA) was developed for detection of human calicivirus in stool specimens. Seventy-eight stool specimens were tested by RIA. All 17 specimens positive for human calicivirus by electron microscopy (EM) were also positive by RIA. In addition, of 21 specimens obtained from an outbreak of caliciviral gastroenteritis, 11 were positive by RIA but negative by EM. Of 20 specimens positive for rotavirus by EM and 20 nondiarrheic specimens with no virus, 2 and 1, respectively, were positive by RIA but were subsequently shown to be falsely positive by a blocking test. There was no cross-reaction between human and feline caliciviruses. Thus, the test was more sensitive than EM and, with an appropriate blocking test, was specific for human calicivirus. It might be especially useful for screening large numbers of stool specimens.

The polypeptide of a human calicivirus.

Viral particles morphologically resembling animals caliciviruses in the faeces of a patient with acute gastroenteritis were purified, radiolabeled with [125I], and analyzed by SDS-PAGE. A single major structural protein with a mol. mass 62,000 daltons was identified by immunoprecipitation technique. The finding is consistent with human calicivirus-like particles associated with gastroenteritis being a member of the family Caliciviridae.

The 33- to 39-nm virus-like particles, tentatively designed as Sapporo agent, associated with an outbreak of acute gastroenteritis.

An outbreak of nonbacterial gastroenteritis occurred in an orphanage in December 1979. Of 54 residents, 43 were affected with acute gastroenteritis. Diarrhea was the commonest symptom. The 33- to 39-nm virus-like particles, tentatively designated as Sapporo agent, were detected in 17 (48.6%) of the patients' 35 fecal specimens. Morphologically, it was difficult to distinguish the Sapporo agent from other agents without geometrical pattern of the surface. Antigenically, the Sapporo agent related to the Otofuke agent detected in an outbreak of the institution for mentally retarded adults and also to the SRV ;76 detected in familial cases of infectious gastroenteritis. The Sapporo agent might belong to a new group of those gastroenteritis viruses which were larger in size than the Norwalk virus group.

Prevalence of antibody to human calicivirus in general population of northern Japan.

Serum specimens from children and adults living in Saporo, Japan, were tested for antibody against human calicivirus by immune electron microscopy (IEM), using virus-rich faecal extracts as the source of antigen. Of 83 serum specimens tested, 49 (59%) were positive for calicivirus antibody. Age-related prevalence of antibody to calicivirus was as follows: 23% (3/13) in the 0-5-month-old group, 30% (6/20) in the 6-23-month-old group, 65% (13/20) in the 2-5-year-old group, and 90% in school children (18/20) and adults (9/10). As for IEM antibody ratings scored from 0 to 4, almost all positive sera from older infants and preschool children scored 3 to 4. Antibody scores were rather more scattered in school children. The results indicated that caliciviral infection is prevalent in younger children in this part of Japan.

Fecal shedding of virus in relation to the days of illness in infantile gastroenteritis due to calicivirus.

Fecal shedding of virus in relation to the days of illness was studied by electron microscopic examinations of stool specimens collected during two consecutive outbreaks of gastroenteritis associated with calicivirus in an orphanage in the city of Sapporo, Japan. Of 61 stool specimens examined, 29 (48%) were found to contain typical calicivirus particles. Although caliciviruses were found in none of the seven stools obtained by chance before the onset of illness, they were found in 18 (95%) of 19 stool specimens collected within four days after the onset of illness. Seven (50%) of 14 specimens collected during the next five days were virus-positive, and the viruses were rarely detected in the stools collected thereafter. Thus correlation between viral shedding and the days of illness was clearly demonstrated. This finding should provide additional evidence for the etiologic role of calicivirus in acute infantile gastroenteritis.

Small round virus-like particles associated with acute gastroenteritis in Japanese children.

Nine patients with acute gastroenteritis shed small round virus-like particles in the faeces, and seven of them developed serum antibody against those particles as judged by immune electron microscopy. The small round virus-like particle was measured at 29-32 nm in diameter and showed a fine spiky structure on the surface. The buoyant density of the small round virus-like particles was determined to be 1.37-1.40 gm/cm3 in cesium chloride density gradient. The small round virus-like particle differed morphologically from astrovirus and calicivirus, and was antigenically dissimilar to Norwalk agent and W agent. These observations suggest that the small round virus-like particle is one of the new gastroenteritis viruses or may be a new serotype of them. Attempts to cultivate the small round virus-like particles were unsuccesful.

Recurrent attack of rotavirus gastroenteritis after adenovirus-induced diarrhoea.

A 14-month-old baby boy suffered a second attack of rotavirus gastroenteritis within one month of the initial one. The second attack followed a diarrhoeal episode associated with adenovirus. Gastrointestinal symptoms in the second attack were more severe than those of the first. The adenovirus-associated enteritis was mild compared with the illness in both episodes of rotavirus infection.

An out-break of acute gastroenteritis due to rotavirus in an infant home.

In December 1976, an outbreak of acute infectious diarrhea occurred among infants who resided in an infant home in the city of Sapporo. Rotavirus infection was proved in 42 (90%) of 47 infants by serologic and/or electron microscopic examinations. Out of 42 infected infants 38(90%) were clinically affected; diarrhea with or without vomiting in 27 (64%), vomiting without diarrhea in 6 (14%) and only febrile episode in 5 (12%). The remaining 4(10%) infants showed no symptoms. Clinical manifestations seemed to differ depending on age. Diarrhea without vomiting was more common in the patients younger than 6 months of age, and vomiting or fever was more common in the groups of older age. Possible reasons for such an age dependency were discussed on the basis of complement-fixation tests using human and calf strains of rotavirus.

A morphological study of human rotavirus.

Human rotavirus has a characteristic icosahedral structure which has a honeycomb-like appearance on the surface of the smooth particles and 42 polygonal capsomeres in the rough particles.

An outbreak of gastroenteritis associated with calicivirus in an infant home.

In October 1977 an outbreak of acute infectious diarrhea occurred in an infant home in the city of Sapporo, Japan. Of 34 residents aged two to 20 months, 26 (77%) suffered from diarrhea. In ten of these patients the diarrhea was accompanied by vomiting. Electron microscopic examinations revealed typical calicivirus particles in eight faecal specimens, seven of which were from the group of 26 affected patients (28%) and one of which was from the group of eight infants without symptoms (13%). Immune electron microscopy tests for antibody responses against one of the isolated strains of calicivirus were carried out on 27 paired pre- and post-outbreak sera. Seroconversions were demonstrated in 18 of 19 (95%) affected infants and in six of eight (75%) unaffected infants. One patient with lack of antibody response was the youngest child--two months old. Periodic surveys on enteric viruses circulating in the home revealed that calicivirus was specifically associated with the outbreak of gastroenteritis. These observations provide further evidence for the causative role of calicivirus in acute gastroenteritis in children.