Epidemiology of hospitalised paediatric community-acquired pneumonia and bacterial pneumonia following the introduction of 13-valent pneumococcal conjugate vaccine in the national immunisation programme in Japan.

Studies on community-acquired pneumonia (CAP) and pneumococcal pneumonia (PP) related to the 13-valent pneumococcal conjugate vaccine (PCV13) introduction in Asia are scarce. This study aimed to investigate the epidemiological and microbiological determinants of hospitalised CAP and PP after PCV13 was introduced in Japan. This observational hospital-based surveillance study included children aged ⩽15 years, admitted to hospitals in and around Chiba City, Japan. Participants had bacterial pneumonia based on a positive blood or sputum culture for bacterial pathogens. Serotype and antibiotic-susceptibility testing of Streptococcus pneumoniae and Haemophilus influenzae isolates from patients with bacterial pneumonia were assessed. The CAP hospitalisation rate per 1000 child-years was 17.7, 14.3 and 9.7 in children aged <5 years and 1.18, 2.64 and 0.69 in children aged 5-15 years in 2008, 2012 and 2018, respectively. There was a 45% and 41% reduction in CAP hospitalisation rates, between the pre-PCV7 and PCV13 periods, respectively. Significant reductions occurred in the proportion of CAP due to PP and PCV13 serotypes. Conversely, no change occurred in the proportion of CAP caused by H. influenzae. The incidence of hospitalised CAP in children aged ⩽15 years was significantly reduced after the introduction of PCV13 in Japan. Continuous surveillance is necessary to detect emerging PP serotypes.

The impact of heptavalent pneumococcal conjugate vaccine on the incidence of childhood community-acquired pneumonia and bacteriologically confirmed pneumococcal pneumonia in Japan.

Heptavalent pneumococcal conjugate vaccine (PCV7) was introduced to Japan in 2010. We investigated the impact of PCV7 on childhood community-acquired pneumonia (CAP) and pneumococcal pneumonia (PP). Children aged <5 years living in Chiba city, Japan, who were admitted to hospitals were enrolled to estimate the incidence of CAP based on the mid-year population. PP was determined by the presence of Streptococcus pneumoniae in cultured blood and/or sputum samples of CAP patients. The incidence of CAP and S. pneumoniae isolated from PP patients was compared before (April 2008-March 2009) and after (April 2012-March 2013) the introduction of PCV7 immunization. The annual incidence of CAP was reduced [incidence rate ratio 0·81, 95% confidence interval (CI) 0·73-0·90]. When comparing post-vaccine with pre-vaccine periods, the odds ratio for PP incidence was 0·60 (95% CI 0·39-0·93, P = 0·024). PCV7-covered serotypes markedly decreased (66·6% in pre-vaccine vs. 15·6% in post-vaccine, P < 0·01), and serotypes 6C, 15A, 15C and 19A increased. Multidrug-resistant international clones in the pre-vaccine period (Spain6B-2/ST90, Taiwan19F-14/ST236) decreased, while Sweden15A-25/ST63 was the dominant clone in the post-vaccine period. A significant reduction in the incidence of both CAP hospitalizations and culture-confirmed PP of vaccine serotypes was observed at 2 years after PCV7 vaccination.

Incidence of childhood pneumonia and serotype and sequence-type distribution in Streptococcus pneumoniae isolates in Japan.

The 7-valent pneumococcal conjugate vaccine (PCV7) is reported to decrease the incidence of community-acquired pneumonia (CAP) in children. To determine the annual incidence of CAP before the introduction of PCV7, we counted the number of children hospitalized with CAP between 2008 and 2009 in Chiba City, Japan. We investigated serotype and multilocus sequence typing (MLST) for Streptococcus pneumoniae isolates in CAP cases. The annual incidence of hospitalized CAP in children aged <5 years was 17.6 episodes/1000 child-years. In 626 episodes, S. pneumoniae was dominant in 14.7% and 0.8% of sputum and blood samples, respectively. The most common serotypes were 6B, 23F and 19F. The coverage rates of PCV7 were 66.7% and 80% in sputum samples and blood samples, respectively. MLST analysis revealed 37 sequence types. Furthermore, 54.1% of the sputum isolates and 40% of the blood isolate were related to international multidrug-resistant clones.

PCR-based capsular serotype determination of Haemophilus influenzae strains recovered from Japanese paediatric patients with invasive infection.

The serotypes of 53 isolates of Haemophilus influenzae from children with invasive infections were determined by a conventional slide agglutination test (SAT) and a recently proposed PCR-based method for serotyping H. influenzae. The PCR assay identified 47 (88.7%) type b isolates, one (1.9%) type e isolate and five (9.4%) non-typeable isolates. The only discrepancy between the methods was an isolate that was non-typeable by SAT, but was identified as serotype e by PCR. Of 41 isolates from patients with meningitis, 39 (95.1%) were type b. Of the five non-typeable isolates, three (60%) were from the blood of patients with septicaemic pneumonia and two (40%) were from the cerebrospinal fluid of patients with meningitis. None of the non-typeable isolates appeared to be a capsule-deficient mutant of an encapsulated H. influenzae strain. Overall, the study confirmed the usefulness of this PCR method for the serotyping of invasive H. influenzae isolates.

Vaccine-modified measles in previously immunized children in Accra, Ghana: clinical, virological and serological parameters.

Despite rapidly increasing measles immunization coverage, epidemics of measles occurred from January to March 2000 in some parts of Accra, the capital of Ghana. 44 cases of acute measles were diagnosed at three health facilities during the outbreaks, which we examined clinically and serologically. The peak incidence occurred among 6-12-year-olds, clinical symptoms were milder than the typical symptoms of measles, and fever was significantly less common. None of the cases developed complications and all recovered completely. Thirty-eight (86.4%) were tested serologically; IgM antibodies were detected in 73.7% and IgG antibodies in 84.2% during the acute phase. Milder symptoms in a significant number of cases with measles IgG antibodies suggest that these are vaccine-modified measles, attributable to waning antibodies and low circulation of wild type virus in an area of high vaccine coverage. Serological confirmation will be required for accurate diagnosis, if measles is to be eradicated or kept under control. It also seems likely that multiple dose immunization schedules will be needed in the future to maintain protective antibody levels and to protect children against measles in Ghana. This will eliminate the frequent outbreaks of measles involving immunized children.

[Clinical analysis of patients with bacterial meningitis in childhood and reevaluation of rapid antigen detection methods].

Twenty-eight cases of bacterial meningitis during the recent ten years were analyzed retrospectively, and the following results were obtained. 1. Pathogens were as follows; H. influenzae 13 (46.4%), S. pneumoniae 8 (28.6%), S. agalactiae 4 (14.3%), E. coli 2 (7.1%), and L. monocytogenes 1 case (3.6%). 2. Twelve out of the thirteen H. influenzae cases were caused by serotype b (Hib), and 2 strains were beta-lactamase producer. Fifty percent of the S. pneumoniae cases were caused by penicillin-resistant strains. And all these resistant strains belonged to serotype 19 or 23. 3. Underlying diseases related to the onset of meningitis were found in 46% of the cases, and these consisted of CNS shunt operated 5, asplenia or polysplenia 2, Mondini's anomaly 1, sacral dermal sinus 1, and neonate 4 cases. 4. Prognosis of these cases were three deaths, four with neurologic sequelae, and twenty-one complete recoveries. 5. On admission, 85% (17/20) of the cases were diagnosed correctly by the rapid antigen detection. Sensitivity and specificity of the rapid antigen detection by using latex particle agglutination is 90% and 100% in the Hib cases, and 83% and 100% in the S. pneumoniae cases respectively. Moreover, the bacteriologically unknown 2 cases caused by parenteral partial treatment were also diagnosed by the detection of antigen in concentrated urine.

Detection of influenza virus RNA by reverse transcription-PCR and proinflammatory cytokines in influenza-virus-associated encephalopathy.

Eleven children with acute encephalopathy associated with an influenza virus infection were treated during the 1997-1998 influenza season. Reverse transcription-polymerase chain reaction (RT-PCR) assay was used to detect the viral genome in peripheral blood and cerebrospinal fluid (CSF) samples. The results were compared with those of control influenza patients without neurological complications. Viral RNA was detected only in the peripheral blood mononuclear cells of one patient with influenza-virus-associated encephalopathy (1 of 9; 11%) and in the CSF of another patient (1 of 11;9%). RT-PCR was negative in the blood of all the controls, but the percentage of RT-PCR-positive samples in the two groups was not significantly different. Cytokines and soluble cytokine receptors in plasma and CSF were then quantified using an enzyme-linked immunosorbent assay. The CSF concentrations of soluble tumor necrosis factor receptor-1 were elevated in two patients and interleukin-6 (IL-6) was elevated in one patient with influenza-virus-associated encephalopathy. On the other hand, the plasma concentrations of IL-6 were elevated in four of nine patients. The number of encephalopathy patients who had elevated plasma concentrations of IL-6 100 pg/ml was significantly higher than that of controls (P= .01). In conclusion, the infrequent detection of the viral genome in the CSF and blood showed that direct invasion of the virus into the central nervous system was an uncommon event. Proinflammatory cytokines and soluble cytokine receptors may mediate the disease. The high plasma concentration of IL-6 could be an indicator of the progression to encephalopathy.

New successful treatment with disinfectant for atopic dermatitis.

For the treatment of atopic dermatitis, a variety of therapies are used including folk medicine. At present, there is no single treatment which is effective to cure the symptoms of atopic dermatitis completely in all patients. We are drawing attention to the high isolation rate of Staphylococcus aureus when starting disinfectant treatment combined with topical steroid therapies for the purpose of killing S. aureus. As a result, we examined many patients in whom almost a complete remission was obtained even after short periods of therapy, though it had been difficult to obtain improvement by conventional treatments. In many patients, IgE values and reagin antibody titer decrease dramatically soon after starting treatment. As a disinfectant, 10% povidone-iodine solution was used. We investigated also the effect of iodine contained in the povidone-iodine solution on the thyroid gland.

[The etiology of acute lower respiratory tract infections in infants].

The etiology of acute lower respiratory tract infections (ALRI) was studied in pediatric inpatients under 2 years of age admitted to Chiba Municipal Hospital between June 1994 and March 1995. Eighty-seven patients, 99 episodes were investigated for bacterial infection with the use of blood culture and washed sputum culture, for viral infection with the use of virus isolation, antigen detection and antibody assays, for Mycoplasma pneumoniae infection with the use of antibody assay and for Chlamydia infection with the use of antigen detection. Pathogens were identified in 71 (71%) of the 99 episodes. Evidence of bacterial infection was detected in 43 episodes (43%), viral infection in 37 episodes (37%), Mycoplasma pneumoniae infection in 4 episodes (4%) and Chlamydia infection 3 episodes (3%). The major bacterial pathogens were H. influenzae, M. (B) catarrhalis and S. pneumoniae. RS virus and influenza virus epidemics occurred during the winter. A mixed bacterial and viral infection was documented in 13 episodes (13%). RS virus infection was common in infants up to 6 months old. Mixed bacterial and influenza virus infections were common in 1 or more year old children. Virus isolation was useful for the grasp of the viral epidemic. Bacterial associated infections were common in children under 2 years of age with ALRI. Washed sputum culture and sputum gram stains' were useful for the treatment of infant ALRI.

Intradural spinal meningioma in a 5-year-old female.

The case of a 5-year-old female with an intradural spinal meningioma is presented. She showed slowly progressive muscle weakness of the lower extremities commencing at 3 years. Spinal magnetic resonance imaging (MRI) demonstrated an intradural mass extending from the eleventh thoracic vertebra to the fifth lumbar vertebra, which was excised totally by means of laminoplasty. The surgical procedure brought a gradual improvement in her gait. This case is unusual because of the tumor's location (lumbar) and origin (cauda equina), and because of the onset at a relatively young age.

[Etiology of pediatric inpatients with pneumonia--analysis of clinical symptoms, physical examination and simple laboratory findings].

In pediatric patients with community-acquired pneumonia, most of the patients have received antibiotics before admission. In this study, we tried to determine whether we could identify the etiology of pneumonia by clinical and laboratory findings on admission. The etiology of acute pneumonia was studied in 596 pediatric inpatients. A pathogen was identified in 384 (64.4%) episodes of pneumonia. These 384 episodes were divided into six groups as follows; I: pneumonia with blood culture positive or pneumonia with bacterial antigen positive in urine, II: pneumonia with dominant bacterial pathogens in washed sputum. III: Mycoplasma pneumonia, IV: viral pneumonia, V: bacterial (I, II) + viral pneumonia, VI: bacterial (I, II) + Mycoplasma pneumonia. These groups were analyzed by clinical symptoms, physical examination and simple laboratory findings on admission. Patients with Mycoplasma pneumonia have increased blood sedimentation rate, high value of positive C-reactive protein and normal white blood cell count. It was difficult to distinguish bacterial pneumonia from viral pneumonia only based upon clinical symptoms, physical examination and simple laboratory findings.

[Etiology of pediatric inpatients with pneumonia].

The etiology of acute pneumonia was studied in 596 pediatric inpatients at Chiba Municipal Kaihin Hospital between January 1990 and December 1991. A pathogen was identified in 389 (64.4%) episodes of pneumonia. Evidence of bacterial infection was present in 167 (28.8%) episodes, viral infection in 178 (29.9%) and Mycoplasma pneumoniae infection in 89 (14.9%). The major bacterial pathogens were H. influenzae 117 (19.6%), S. pneumoniae 51 (8.6%), M (B). catarrhalis 24 (4.0%). RS virus was the most common respiratory virus. The peak age of the patients was 7 months to 2 years old. For bacterial pneumonia, the highest rates occurred in infants. Mycoplasma pneumonia produced the highest rates in school-age children. Mycoplasma pneumonia was prevalent at two distinct times, the first emerging in the spring of 1990 and emerging again in the autumn of 1991. RS virus and influenza virus epidemics occur during the winter. Most of the parainfluenza virus have been observed during the early summer season.