Nobuyasu Ishikawa

NASOPHARYNGEAL COLONIZATION WITH HAEMOPHILUS INFLUENZAE TYPE B AMONG INFANTS AND CHILDREN IN JAPAN

Healthy carriers of Haemophilus influenzae type b (Hib) play an important role in the spread of invasive Hib disease. The aim of the present study was to estimate Hib colonization among infants and children in Japan. Specimens from throat and nasopharyngeal cultures were obtained by thorough swabbing of both tonsils and the posterior pharynx. Specimens were inoculated on Hib antiserum agar. This was prepared with Levinthal base and Hib antiserum. Conventional methods were used concomitantly. Four of 474 infants from 1–48 months of age (0.84%) had Hib cultured from their nasopharynx. The carriage rate in 1–12 month old infants was 0.62% (2/322 cases), and that in 13–48 month old children was 1.32% (2/152 cases). Five of 167 (3.0%) 13‐year‐old children, and five of 154 (3.2%) 9‐year‐old children were asymptomatic carriers. Thirty‐five of 104 household contacts of a patient with invasive Hib disease (33.6%) had Hib colonization. The carriage rate in healthy Japanese children may not be different from that in the USA prior to the availability of the conjugate Hib vaccine. The Hib carriage rate in household contacts of patients with invasive Hib disease was higher than in healthy children (P < 0.005). Our results suggest the possibility of an outbreak of invasive Hib disease in Japan.

The Importance of Disinfection Therapy Using Povidone-Iodine Solution in Atopic Dermatitis

The combination of the local disinfection therapy against Staphylococcus aureus with the conventional therapy for atopic dermatitis has been widely used, and the improvement in skin lesions has been reported to be associated with a remarkable decrease in IgE levels and reagin antibody titers. We have already reported that affected organs were not only the skin but also the gastrointestinal tract in a case with atopic dermatitis. In the present study, the duodenal tissues were examined by biopsy in 32 patients with atopic dermatitis, and mild or chronic duodenitis was observed in all samples. Toxins were examined by PCR from 180 Staphylococcus aureus strains obtained from our patients. The detection rate of toxins was 82.8%. In many patients, antitoxin IgE antibody titers corresponding to their types of toxin and IgE levels were decreased in a parallel manner as time passed. We found 1 patient who complained of paresthesia in all four limbs, and her neurological and radiological examinations showed moderate cervical spondylosis. Neurological examinations revealed some abnormalities in 43 out of 50 patients with atopic dermatitis, such as hyperreflexia of the legs. Cervical MRI was carried out randomly and showed abnormal findings in 21 of 25 patients, in whom 18 duodenal tissues were examined by biopsies.

The Importance of Bacterial Superantigens Produced by Staphylococcus aureus in the Treatment of Atopic Dermatitis Using Povidone-Iodine

Atopic dermatitis (AD) is frequently associated with intestinal and cervical lesions. Staphylococcus aureus produces many kinds of toxins, the bacterial superantigens. The detection rate of toxins was 80.1% from 196 S. aureus strains. Neurological examinations revealed abnormalities in 59 out of 81 AD patients. Cervical magnetic resonance imaging (MRI) was performed in 46 patients randomly and showed abnormal findings in 38 of these patients. In 23 patients who underwent MRI and duodenal biopsy, 3 were found to be normal neurologically and 2 patients showed normal duodenal tissue. However, 18 patients had abnormal findings both on neurological examination and in duodenal tissue. Serial duodenal biopsy tests were performed in 10 AD patients. In 5 patients, the findings of chronic duodenitis disappeared after the therapy with povidone-iodine. These data indicate that the therapy was effective not only for the skin lesions, but improved gastrointestinal tract lesions and cervical myelopathy, by eradicating bacterial superantigens.

Characteristics of β-Lactamase-Producing and Amoxicillin-Clavulanate-Resistant Strains of Haemophilus influenzae Isolated from Pediatric Patients

A total of 1246 clinical isolates ofHaemophilus influenzae from pediatric patients were recovered in Chiba Municipal Hospital. We studied the characteristics of these strains with regard to β-lactamase production and in vitro activities of antimicrobial agents between January 1995 and June 1997. Two hundred and ten strains (16.8%) of these isolates produced β-lactamase. Eight β-lactamase-positive isolates were resistant to amoxicillin-clavulanate (MICs, ≥12 μg/mL). Most of these were isolated from respiratory tracts. These strains were mainly cultured from boys less than 3 years old with chronic respiratory disease. Two strains were serotype b and 6 strains were not typeable. Some of these strains were eradicated without antibiotic treatment. Although the clinical impact of β-lactamase-producing and amoxicillin-clavulanate-resistantHaemophilus influenzae remains low, the number of infections caused by these strains may increase in the near future. We must monitor this tendency.

Intractable wheezing in infants with nasopharyngeal reflux

Two infants with intractable wheezing and moist cough were referred to Chiba Municipal Kaihin Hospital. Their symptoms were persistent even after the usual treatment for respiratory disease. No definite etiological agents were detected. They usually gagged while feeding and barium swallow tests revealed nasopharyngeal reflux and cricopharyngeal incoordination. One of the patients had remarkably high titers of IgE and IgE RAST of cows milk before she received treatment with thickened formula. She also had peripheral eosinophilia and nasal eosinophilia. These findings were thought to be caused by nasopharyngeal reflux. Four months after therapy commenced, those titers and symptoms were greatly reduced. The clinical and roentgenographic findings in these infants, and their response to therapy, strongly support a causal relationship between nasopharyngeal reflux and wheezing. Therefore, nasopharyngeal reflux should be considered when a baby has intractable wheezing, even when there is no developmental problem.

Recent Chemotherapy for Child Pneunomia and Empyema

Recent progress in chemotherapy has contributed to the remarkable decrease in mortality from pneumonia in infancy and childhood; however, wide use of antimicrobials has resulted in incapability of etiologic diagnosis. Appropriate chemotherapy for pneumonia should be initiated based on the relative frequency of causative organisms related to age groups, and their antimicrobial susceptibility. Therapeutic development should be reevaluated by the pathogens isolated prior to antimicrobial administration.