Upper respiratory tract bacterial carriage in Aboriginal and non-Aboriginal children in a semi-arid area of Western Australia

BACKGROUND: Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis are associated with otitis media (OM). Indigenous children experience particularly high rates of OM. Few studies worldwide have described upper respiratory tract (URT) carriage in Indigenous and non-Indigenous children living in the same area. AIM: The aim of this study was to describe URT bacterial carriage in Aboriginal and non-Aboriginal children in the Kalgoorlie-Boulder area, Western Australia, as part of an investigation into causal pathways to OM. METHODS: Five hundred four and 1045 nasopharyngeal aspirates were collected from 100 Aboriginal and 180 non-Aboriginal children, respectively, followed from birth to age 2 years. Standard procedures were used to identify bacteria. RESULTS: Overall carriage rates of S. pneumoniae, M. catarrhalis and H. influenzae in Aboriginal children were 49%, 50% and 41%, respectively, and 25%, 25% and 11% in non-Aboriginal children. By age 2 months S. pneumoniae and M. catarrhalis had been isolated from 37% and 36% of Aboriginal children and from 11% and 12% of non-Aboriginal children, respectively. From age 3 months onward, carriage rates in Aboriginal children were 51% to 67% for S. pneumoniae and M. catarrhalis and 42% to 62% for H. influenzae; corresponding figures for non-Aboriginal children were 26% to 37% for S. pneumoniae and M. catarrhalis and 11% to 18% for H. influenzae. Non-Aboriginal children had higher carriage rates in winter than in summer, but season had little effect in Aboriginal children. Staphylococcus aureus carriage was highest under age 1 month (55% Aboriginal, 61% non-Aboriginal) and was always higher in non-Aboriginal than Aboriginal children. CONCLUSIONS: Interventions are needed to reduce high transmission and carriage rates, particularly in Aboriginal communities, to avoid the serious consequences of OM.     

Risk factors for carriage of respiratory pathogens in the nasopharynx of healthy children. Ascanius Project Collaborative Group.

OBJECTIVES: To assess risk factors for nasopharyngeal carriage of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis in a large sample of healthy children. METHODS: In this point prevalence survey nasopharyngeal specimens were obtained from 1723 healthy children, ages 1 to 7 years, attending day-care centers or schools in 18 Italian cities. Written questionnaires for obtaining information about the demographics and medical history of the children were completed by the parents in the presence of a pediatrician. RESULTS: The overall carrier rate of respiratory pathogens was 17.9% (S. pneumoniae, 3.5%; H. influenzae, 11.9%; M. catarrhalis, 4.1%). Only 5% of S. pneumoniae strains were penicillin-resistant whereas approximately 40% were erythromycin-resistant. Beta-lactamase production was found in 5.8% of H. influenzae and 88.7% of M. catarrhalis isolates. By multivariate analysis age (< or = 3 years), having older siblings, a history of prolonged full-time day-care attendance and living in a rural area significantly influenced the odds of carrying nasopharyngeal respiratory pathogens, particularly in children ages 1 to 5 years. Sex, breastfeeding, passive smoking and recent upper respiratory tract infections were not significant variables. Antibiotic treatment in the previous 3 months did not affect nasopharyngeal carriage, whereas repeated treatments with a macrolide were associated with carriage of S. pneumoniae. CONCLUSIONS: Our results suggest that there is a strong and long term relationship between exposure to large numbers of children in the first years of life and nasopharyngeal carriage of all respiratory pathogens. In addition antimicrobial restrictive guidelines should be tailored to local microbiologic sceneries.     

健康儿童鼻咽部常见致病微生物携带状况及临床意义

目的：了解健康儿童鼻咽部常见致病微生物携带状况，探讨小儿呼吸道感染病原诊断中鼻咽分泌物检测的临床价值及依据。方法：对2294名健康儿童及患儿取咽拭子或抽吸鼻咽分泌物进行检测。其中1906名儿童之咽拭子标本用聚合酶链反应（PCR）法检测肺炎支原体（MP）；307名儿童取咽拭子行细菌培养，81名儿童取鼻咽分泌物（NPS）进行呼吸道合胞病毒（RSV）及腺病毒（ADV）分离。同期对患儿也进行了相应病原检测。结果：1906名健康儿童中肺炎支原体阳性者28名，占1．47％，而544例急性下呼吸道感染者中阳性者107例，占19．67％，P＜0．001，健康儿童中肺炎链球菌，流感嗜血杆菌，金黄色葡萄球菌，表皮葡萄球菌，A组乙型溶血性链球菌（GAS）的平均带菌阳性率分别为18．6％，6．5％，2．3％，2．0％，2．0％，未发现脑膜炎双球菌；34例急性扁桃炎患儿GAS阳性者26例，占76．5％，P＜0．001。81名健康婴幼儿呼吸道合胞病毒携带者3例，占3．7％，呼吸道3，7型腺病毒携带者1例占1．2％，而136例下呼吸道感染患儿RSV中阳性者51例，占37．5％，P＜0．001。结论：健康儿童鼻咽部肺炎支原体，腺病毒，呼吸道合胞病毒，A组乙型溶血性链球菌及脑膜炎双球菌的携带者均很少，检测阳性者，有重要诊断意义，肺炎链球菌及流感嗜血杆菌等在健康人中的检出率较高，不能代表呼吸道感染的病原菌，但应密切结合临床分析，给予必要的重视。     

Incidences of nasopharyngeal colonization of respiratory bacterial pathogens in Japanese children attending day-care centers

BACKGROUND: In Japan, many younger children attending day-care centers tend to frequently experience acute respiratory infections and prolonged otitis media. OBJECTIVES: To evaluate the carriage rate of respiratory bacterial pathogens in children attending day-care centers in our district. METHODS: Nasopharyngeal cultures of 156 healthy children between the ages of 1 month and 5 years were conducted at two day-care centers in Japan, in April 1999. The carriage rates of four major pathogens (Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Staphylococcus aureus) and the antibiotic susceptibilities of the isolates were examined. RESULTS: Streptococcus pneumoniae, H. influenzae, M. catarrhalis and S. aureus were detected in 94 (60.3%), 83 (53.2%), 54 (34.6%) and 28 (17.9%) children, respectively. A total of 141 (90.4%) children carried at least one pathogen among these four pathogens and 87 (55.8%) children carried more than one pathogen. Fifty-seven of the 94 (60.6%) S. pneumoniae isolates were penicillin-intermediately or highly resistant strains of S. pneumoniae (PISP/PRSP). Beta-lactamase producing H. influenzae was not detected. Twelve of the 28 (42.9%) S. aureus isolates were methicillin-resistant. The incidence of colonization by PISP/PRSP in children younger than 3 years (43/69, 62.3%) was significantly higher than that in children aged 3-5 years (14/87, 16.1%) (P < 0.0001). CONCLUSIONS: We conclude that the rates of colonization by respiratory bacterial pathogens, especially by antibiotic-resistant strains, were high in children attending day-care centers in our district, suggesting their horizontal spread among children in day-care centers. Considering that the majority of children attending day- care centers carried one or more of the bacterial pathogens, the judicious use of antimicrobials will be required to prevent the increase of antibiotic-resistant rates among the colonizing pathogens.     

Colonisation of Haemophilus influenzae and Streptococcus pneumoniae in the upper respiratory tract of neonates in Papua New Guinea: primary acquisition, duration of carriage, and relationship to carriage in mothers

In order to determine the age of acquisition and duration of carriage of the first strains of Haemophilus influenzae and Streptococcus pneumoniae in the upper respiratory tract of Papua New Guinea children, 25 babies were recruited at, or shortly after birth. Nasal secretions from mothers and children were cultured at 1- to 2-weekly intervals. H. influenzae and S. pneumoniae were acquired within the neonatal period by 60% of the infants, and all were colonised by both organisms within the first 3 months of life. Carriage periods for H. influenzae ranged from 6 to 221 days (mean, 74 days), and for S. pneumoniae from 5 to 290 days (mean, 96 days). Penicillin resistance was detected in 36% of the first acquired strains of pneumococci. Mothers, generally either did not carry H. influenzae or S. pneumoniae, or harboured types different to those first acquired by their infants. However, one-third of mothers subsequently became colonised with H. influenzae and S. pneumoniae types similar to those carried by their babies.     

Changes in nasopharyngeal flora during otitis media of childhood

The nasopharyngeal flora of healthy children were compared with flora in children with otitis media caused by nontypable Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis. Forty healthy children were followed prospectively and compared with 70 children with 43 episodes of nontypable H. influenzae, 21 episodes of S. pneumoniae and 28 episodes of M. catarrhalis otitis media. Carriage of nontypable H. influenzae (95% vs. 65%, P less than 0.001), S. pneumoniae (91% vs. 52%, P less than 0.005) and M. catarrhalis (86% vs. 52%, P less than 0.001) increased significantly during episodes of otitis media compared with healthy periods. The quantity of nontypable H. influenzae, S. pneumoniae and M. catarrhalis in nasopharyngeal secretions also increased during active infection compared with healthy periods: 3.0 vs. 2.0, P less than 0.005; 3.2 vs. 2.1, P less than 0.001; and 3.3 vs. 2.5, P less than 0.01, respectively. At the same time, nonpathogens of the resident flora, in particular viridans streptococci, declined in carriage: 65% vs. 22%, P less than 0.001. These data suggest that respiratory pathogens become relatively more important in the microenvironment of the nasopharynx during episodes of otitis media. Furthermore the absence of a middle ear pathogen in a nasopharyngeal culture strongly suggests that the pathogen is not present in the middle ear space (negative predictive value greater than 0.96).     

Differences in nasopharyngeal bacterial flora in children with nonsevere recurrent acute otitis media and chronic otitis media with effusion: implications for management

BACKGROUND: The interactions between nasopharyngeal flora and the individual entities covered by the broad term otitis media have not been completely elucidated. We investigated in infants and children ages 6 months to 7 years with nonsevere recurrent acute otitis media (rAOM) or with chronic otitis media with effusion (cOME): (1) the nasopharyngeal carriage rate and bacterial density of respiratory pathogens and alpha-hemolytic streptococci in comparison with healthy children; (2) the resistance pattern of respiratory pathogens; and (3) the relationship between the type of nasopharyngeal colonization and long term outcome. METHODS: Nasopharyngeal cultures were obtained from 85 children with rAOM,113 children with cOME and 55 controls. A semiquantitative analysis was used in the reading of cultures. A 12-week follow-up without treatment was planned. RESULTS: The carrier rate of respiratory pathogens was significantly greater in cOME (70%) than in rAOM (45%) (P = 0.0006) or controls (31%) (P < 0.0001). Similarly colonization density was significantly greater in cOME than in rAOM. The carriage rate and the colonization density of alpha-hemolytic streptococci were significantly lower in rAOM than in cOME or controls. The incidence of resistant (R) strains was greater in rAOM (Streptococcus pneumoniae penicillin-R, 24%; macrolide-R, 64%; Haemophilus influenzae amoxicillin-R, 24%) compared with cOME (S. pneumoniae penicillin-R,18%; macrolide-R, 44%; H. influenzae amoxicillin-R, 5%) or controls (S. pneumoniae penicillin-R, 8%; macrolide-R, 23%; H. influenzae amoxicillin-R, 10%). During the follow-up period persistence of OME and occurrence of AOM were greater among carriers of respiratory pathogens at baseline. CONCLUSIONS: There are substantial differences in nasopharyngeal flora between children with nonsevere rAOM and children with cOME. The results of nasopharyngeal cultures should be taken into account to avoid treatment with drugs that are ineffective and likely to select resistant organisms.     

Streptococcus pneumoniae and noncapsular Haemophilus influenzae nasal carriage and hand contamination in children: a comparison of two populations at risk of otitis media

BACKGROUND: Australian Indigenous children living in remote areas have rates of tympanic membrane perforation as high as 60%, almost 100 times the prevalence in urban child care settings (<1%). Relative rates of pneumococcal nasal carriage do not reflect this difference in disease risk. METHODS: Cross-sectional comparison of nasal carriage and hand contamination in children younger than 4 years of age from urban child-care centers and Indigenous children 3-7 years of age from a remote community. Almost identical methods of nasal swab collection, transport and culture were used. Data on pneumococcal antimicrobial susceptibility patterns and serotypes are also reported. RESULTS: For Indigenous children compared with children in child care, the relative risk of nasal carriage of either pneumococcus or noncapsular Haemophilus influenzae was <2-fold [relative risk, 1.7; 95% confidence interval (CI), 1.5, 1.9], the risk of simultaneous nasal carriage was almost 3-fold (78% versus 28%; relative risk, 2.9; 95% CI 2.3, 3.5), and the risk of pneumococcal hand contamination was 8-fold higher (37% versus 4%; relative risk, 8.4; 95% CI 4.6, 15.2). For simultaneous hand contamination, the risk was 23-fold (8% versus 0.3%; relative risk, 23.1; 95% CI 2.9, 185.4). Remote Indigenous children also had a more diverse serotype distribution (25 versus 14 serotypes identified). CONCLUSIONS: Simultaneous nasal carriage of Streptococcus pneumoniae and H. influenzae and hand contamination are simple indicators of risk for use in studies of otitis media in populations at risk for tympanic membrane perforation.     

Clinical and bacterial characteristics of acute bacterial conjunctivitis in children in the antibiotic resistance era

BACKGROUND: Acute conjunctivitis is the most common eye disorder in young children. Bacteria are responsible for 54-73% of all cases. The goals of the study were to identify the rates of Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis in cases of bacterial conjunctivitis in children and to define antibiotic resistance rates. METHODS: During a 2-year study period, conjunctival swabs of children 2-36 months old were collected prospectively. Nontypable H. influenzae, S. pneumoniae and M. catarrhalis were defined as the study pathogens. Analyzed variables included demography, clinical presentation, bacteriologic results and susceptibility patterns. RESULTS: There were 428 patients enrolled. Of all cultures, 55% (237 of 428) yielded at least 1 of the study pathogens. H. influenzae and S. pneumoniae were isolated from 29 and 20% of cultures, respectively. beta-Lactamase production was found in 29% of H. influenzae isolates, and penicillin nonsusceptibility was observed in 60% of S. pneumoniae isolates. The most common S. pneumoniae serotypes were: 19F (14%); 6A and 14 (11% each). Nontypable S. pneumoniae was found in 12%. The 7-valent pneumococcal conjugate vaccine (PCV-7) could potentially cover 44% of all isolates. Conjunctivitis-otitis syndrome was found in 32% of patients, of whom 82% of cultures yielded H. influenzae. CONCLUSIONS: Antibiotic resistance rates are alarmingly high. Conjunctivitis-otitis syndrome, predominantly caused by H. influenzae, is quite common. The potential coverage of the PCV-7 in conjunctivitis is relatively lower than that reported in other pneumococcal infections. Our findings should alert physicians on the choice of appropriate antibiotic treatment, on the frequent copresence of acute otitis media and on the potential role of conjunctivitis in the spread of antibiotic-resistant pathogens.     

小儿下呼吸道感染的细菌病原学分析

目的：下呼吸道感染是造成儿童住院的最常见疾病之一。在发展中国家,病原菌以细菌感染相对多见,而病原菌的分布特点则常因年代不同而发生变迁。该研究的目的是了解本地区小儿下呼吸道感染常见病原菌及其对常用抗生素的耐药性,为临床药物治疗提供有价值的参考。方法：对2001年8月至2002年7月住院的所有下呼吸道感染患儿,常规进行深部痰培养,并用纸片扩散法、Etest法和Vitek系统进行药敏试验。结果：下呼吸道感染儿共4238例,其中1181例分离到1种或1种以上致病菌,阳性率为27.9%,最常见的病原菌为肺炎链球菌、流感嗜血杆菌、肺炎克雷伯菌、大肠埃希菌和金黄色葡萄球菌,分离率分别为5.2%,5.1%,5.1%,4.0%和2.1%。女性患儿肺炎链球菌的分离率显著高于男性(χ2=4.63,P<0.05),而肺炎克雷伯菌和金黄色葡萄球菌在男性中的分离率均高于女性(χ2=5.71,4.57,P<0.05)。年龄分布显示,1~3岁是肺炎链球菌和流感嗜血杆菌的好发年龄段,而肺炎克雷伯菌、大肠埃希菌、金黄色葡萄球菌和阴沟肠杆菌以及非常见菌感染则在1岁以内的婴儿中多见。季节分布上,12月份至3月份是大多数细菌感染分布较集中的时段。药敏结果显示青霉素不敏感肺炎链球菌、耐氨苄西林流感嗜血杆菌、耐苯唑西林金黄色葡萄球菌和产ESBL肺炎克雷伯菌、大肠埃希菌的比率分别为55.0%,16.5%,41.2%,42.6%和4.5%。结论：肺炎链球菌、流感嗜血杆菌、肺炎克雷伯菌、大肠埃希菌和金黄色葡萄球菌是小儿下呼吸道感染常见致病菌,但在不同年龄的感染率存在明显差异,治疗上应根据药敏结果选择敏感抗生素。     

Meningitis in Hong Kong children, with special reference to the infrequency of haemophilus and meningococcal infection

Objective: To study the epidemiologic and aetiologic features of meningitis in children in Hong Kong.
Methodology: A retrospective study of 85 children resident in the New Territory East region of Hong Kong admitted to a teaching Hospital because of meningitis during a 9 year period.
Results: Mycobacterium tuberculosis was the most common aetiological agent accounting for 13 cases (15.3%). Other bacteria accounted for 41 cases (48%); among these one fifth were caused by Haemophilus influenzae type b. The overall admission rates for tuberculous meningitis in Chinese children were 0.76/100 000 (95% CI 0.25-1.78) and 0.42/100 000 (CI 0.19-0.8) per year, respectively, for under 5 year olds and under 15 year olds. The overall annual incidence rates of bacterial meningitis other than tuberculous were 5.2/100 000 (CI 3.72-7.43) and 1.6/100 000 (CI 1.14-2.29) for Chinese children under 5 years and under 15 years, respectively. The annual incidence of H. influenzae meningitis in Chinese children under 5 years old was low at 1.1/100 000 (0.43-2.2). All five cases of meningococcal meningitis were in Vietnamese children (under 5 years of age incidence: 13.0/100 000 per year, CI 4.2-30.3). There were no cases of meningococcal meningitis in Chinese children during the 9 year period.
Conclusion: M. tuberculosis was the most common aetiological agent of meningitis in Hong Kong children. The incidence of haemophilus or meningococcal meningitis was very low.     

学龄前儿童肺炎链球菌和卡他莫拉菌携带状态及影响因素分析北大核心CSCD

目的了解学龄前儿童肺炎链球菌和卡他莫拉菌的携带状态及影响因素。方法采用分层整群抽样方法抽取广东省佛山市顺德区7所幼儿园中共2031名健康儿童为研究对象,对所有儿童进行鼻拭子采样并分离鉴定肺炎链球菌和卡他莫拉菌。分析儿童肺炎链球菌和卡他莫拉菌的不同携带状态与其人口学特征、医院/社区相关因素的关系。结果学龄前儿童鼻腔肺炎链球菌携带率为21.81%,卡他莫拉菌携带率为52.44%,肺炎链球菌和卡他莫拉菌的共携带率为14.87%。对应分析表明,低年龄班、外市户籍、现居住农村、居住面积小、有呼吸道感染史且无抗生素使用史、有过敏性皮肤病、无医院相关暴露史与儿童肺炎链球菌和卡他莫拉菌的共携带显著相关(P<0.05)。结论学龄前儿童存在肺炎链球菌和卡他莫拉菌的共携带现象;年龄小、不良的居住环境、有呼吸道感染史且无抗生素使用史、有过敏性皮肤病、无医院相关暴露史是学龄前儿童肺炎链球菌和卡他莫拉菌共携带的重要危险因素。[中国当代儿科杂志,2022,24(8):874-880]     

Acquisition of Streptococcus pneumoniae and nonspecific morbidity in infants and their families: a cohort study

BACKGROUND: Most children are believed to acquire Streptococcus pneumoniae asymptomatically, with only a few developing overt S. pneumoniae disease. This study investigates the relationship between acquisition of S. pneumoniae and mild nonspecific infection leading to general practitioner (GP) consultation. METHODS: A prospective birth cohort study of 213 infants assessed at home 9 times during 24 weeks by nasopharyngeal swab and parental interview was conducted. RESULTS: All positive S. pneumoniae swabs (including acquisition and carriage) were significantly associated with GP consultations for infection by the study infant compared with infants with negative swabs [odds ratio (OR), 1.6; 95% confidence interval (CI) 1.1-2.2; P = 0.005]. There was a stronger association with S. pneumoniae acquisition alone (OR 2.1; 95% CI 1.3-3.4; P = 0.001) than with carriage only (OR 1.4; 95% CI 0.9-2.0; P = 0.1). Multivariate analysis confirmed that S. pneumoniae acquisition by the study subject was independently associated with GP consultations: adjusted hazard ratio, 1.8 (95% CI 1.1-2.9); P = 0.02. A similar and independent association was found between S. pneumoniae acquisition by the study subject, and GP consultations for infection by the family (adjusted hazard ratio, 1.8; 95% CI 1.1-2.8; P = 0.01). CONCLUSION: Acquisition of S. pneumoniae by the study infant was significantly associated with GP consultations for infection by the infant or family.     

Severity and frequency of sequelae of bacterial meningitis in Alaska Native infants. Correlation with a scoring system for severity of sequelae.

OBJECTIVES--To (1) determine the frequency and severity of sequelae of Haemophilus influenzae type b and Streptococcus pneumoniae meningitis in Alaska Native children, (2) compare morbidity and mortality of H influenzae b and S pneumoniae meningitis, and (3) evaluate the applicability of the Herson-Todd prognostic score (HTPS) to both H influenzae b and S pneumoniae meningitis in this population. DESIGN--A retrospective study of all cases of H influenzae b and S pneumoniae meningitis in Alaska Native children younger than age 5 years. Data on meningitis sequelae, obtained from medical charts and records of the Infant Learning Program, were collected, and incidence of sequelae tabulated. Data obtained on admission to the hospital were used to calculate HTPS. SETTING--Indian Health Service facility for the Yukon-Kuskokwin Delta region of southwest Alaska. STUDY SUBJECTS--51 of 63 Alaska Native children with H influenzae b meningitis and 13 of the same 63 Alaska Native children with S pneumoniae meningitis occurring between 1980 and 1988. One child was infected with both organisms, producing a total of 64 cases for study. SELECTION PROCEDURES--Cases were identified by surveillance for these diseases between January 1, 1980, and December 31, 1988, maintained by the Arctic Investigations Program, Centers for Disease Control. MEASUREMENTS AND RESULTS--Sequelae of bacterial meningitis caused by H influenzae b were equal to or exceeded rates of sequelae described in other children in the United States. After H influenzae b meningitis, motor abnormalities (29%) and hydrocephalus (7%) occurred two to four times more often in Alaska Native children than in children in other parts of the United States. Differences in severity of H influenzae b sequelae could not be accounted for by microbiologic markers of the H influenzae b strain, including ampicillin sensitivity, biotype, outer membrane protein type, or electropherotype. Numbers of cases of S pneumoniae meningitis were too small for statistically valid comparison, but sequelae of S pneumoniae meningitis occurred in roughly equal proportion as sequelae of H influenzae b meningitis. The HTPS was applied to Alaska Native children with H influenzae b meningitis and was found to be very accurate in predicting children with major sequelae. Analysis of the prognostic factors used in deriving the HTPS revealed a unique set of predictors for sequelae in Alaska Native children: seizures at admission, glucose levels in cerebrospinal fluid of less than 1.1 mmol/L; and male gender, with a significant predictive interaction between male gender and age less than 6 months at admission. CONCLUSIONS--Alaska Native children suffer greater neurologic morbidity as a result of H influenzae b meningitis than do their non-Native counterparts. The HTPS was a good predictor of major sequelae in Alaska Native children with H influenzae b or S pneumoniae meningitis and could be useful in determining which patients need referral to a tertiary care center.     

Seasonal distribution of otitis media pathogens among Costa Rican children

BACKGROUND: Otitis media is an important cause of pediatric consultation, and knowledge of yearly pathogen distribution might improve antimicrobial selection. OBJECTIVES: To determine the seasonal pathogen and antimicrobial resistance distribution among Costa Rican children with otitis media. METHODS: Between 1999 and 2004, 952 children with otitis media, aged 3-144 months who participated in various clinical trials, were analyzed. Data obtained from this period were compared against historical data collected between 1992 and 1997. RESULTS: Five hundred sixteen (52%) children had a baseline middle ear fluid pathogen isolated. The most common pathogens were Streptococcus pneumoniae 252 (49%), Haemophilus influenzae 190 (37%), S. pyogenes 38 (7%), and Moraxella catarrhalis 36 (7%). The overall proportion of H. influenzae (24-37%; P = 0.01) and the production of beta-lactamase producing H. influenzae (2.6-7%; P = 0.02) increased from 1992-1997 to 1999-2004. There was a nonstatistically significant trend for a higher frequency of S. pneumoniae and H. influenzae isolates detected during the rainy season than during the dry season: S. pneumoniae 58% versus 42% but not significant (P = 0.1) and H. influenzae 68% versus 32% (P = 0.06), respectively. During the rainy season, penicillin-nonsusceptible S. pneumoniae was identified more frequently (38.5%) than during the dry season (18%) (P = 0.003; odds ratio: 2.94; 95% confidence interval: 1.4-6.45). Penicillin-nonsusceptible S. pneumoniae decreased from 46.5% (1999-2001) to 16% (2002-2003) and this was associated with a significant decline of a circulating 19F penicillin-resistant S. pneumoniae serotype (from 89% to 26%), respectively. CONCLUSIONS: S. pneumoniae and H. influenzae are the 2 most common pathogens producing otitis media in Costa Rican children. An increase in the number of H. influenzae and M. catarrhalis was observed in recent years. Penicillin-nonsusceptible S. pneumoniae isolates were more commonly observed during the rainy season, in which increased morbidity with respiratory pathogens is observed.     

Nasopharyngeal carriage of penicillin-resistant Streptococcus pneumoniae in healthy children

Streptococcus pneumoniae carriage is a risk factor for the development of respiratory system infections and the spread of penicillin-resistant strains. The aim of this study was to investigate nasopharyngeal carriage of S. pneumoniae in healthy children and resistance to penicillin and other antimicrobials and to assess related risk factors. Nasopharyngeal specimens collected from healthy children less than six years of age, visiting a Mother and Child Health Center for health control, were investigated microbiologically between February-March 2004. Carriage rate was 37.2% (n=112/301); 33.9% intermediate and 5.4% high penicillin resistance were detected. According to multivariate analysis, carriage rate was inversely related to number of rooms (OR:0.574) and child age (OR:0.978), while penicillin resistance was correlated well with antibiotic use in the last two months (OR:2.193). Decreased sensitivity plus resistance to other antimicrobials were: trimethoprim-sulfamethoxazole (TMP-SMX) 45.6%; erythromycin 16.1%, tetracycline 16.1%; clindamycin 9.8%, and ofloxacin 3.6% in pneumococcal isolates, which increased significantly (p<0.05) to 72.7%, 31.8%, 27.3%, 20.5%, and 6.8%, respectively, in penicillin non-sensitive S. pneumoniae (PNSSP) except for ofloxacin. Overall multidrug resistance was 17.9%, while PNSSP exhibited a resistance rate of 38.6%. In conclusion, S. pneumoniae carriage rates determined in healthy children were high and PNSSP strains also showed increased resistance to other antimicrobials.     

The descriptive epidemiology of Streptococcus pneumoniae and Haemophilus influenzae nasopharyngeal carriage in children and adults in Kilifi district, Kenya

BACKGROUND: Transmission and nasopharyngeal colonization are necessary steps en route to invasive pneumococcal or Haemophilus influenzae disease but their patterns vary geographically. In East Africa we do not know how these pathogens are transmitted between population subgroups nor which serotypes circulate commonly. METHODS: We did 2 cross-sectional nasopharyngeal swab surveys selecting subjects randomly from a population register to estimate prevalence and risk-factors for carriage in 2004. H. influenzae type b vaccine was introduced in 2001. RESULTS: Of 450 individuals sampled in the dry season, 414 were resampled during the rainy season. Among subjects 0-4, 5-9, and 10-85 years old pneumococcal carriage prevalence was 57%, 41%, and 6.4%, respectively. H. influenzae prevalence was 26%, 24%, and 3.0%, respectively. Prevalence of H. influenzae type b in children <5 years was 1.7%. Significant risk factors for pneumococcal carriage were rainy season (odds ratio [OR]: 1.65), coryza (OR: 2.29), and coculture of noncapsulate H. influenzae (OR: 7.46). Coryza was also a risk factor for H. influenzae carriage (OR: 1.90). Of 128 H. influenzae isolates, 113 were noncapsulate. Among 279 isolates of Streptococcus pneumoniae, 40 serotypes were represented and the distribution of serotypes varied significantly with age; 7-valent vaccine-types, vaccine-related types, and nonvaccine types comprised 47%, 19%, and 34% of strains from children aged <5 years. Among older persons they comprised 25%, 28%, and 47%, respectively (P = 0.005). CONCLUSIONS: The study shows that pneumococcal carriage is common up to 9 years of age and that the majority of serotypes carried at all ages are not covered specifically by the 7-valent pneumococcal conjugate vaccine.     

2000至2006年复旦大学附属儿科医院呼吸道感染患儿4种常见细菌分离率及耐药趋势

摘要 目的 了解复旦大学附属儿科医院2000至2006年呼吸道感染患儿流感嗜血杆菌、肺炎链球菌、化脓性链球菌和卡他莫拉菌的分离率及耐药趋势。方法 对29 416例呼吸道感染患儿进行4种致病菌分离率及耐药趋势回顾，细菌分离培养采用常规方法，药敏试验采用KB琼脂扩散法。结果 化脓性链球菌年分离率为10.7%～25.4%，占咽拭子致病菌首位，呈逐年上升趋势（P=0.01）。流感嗜血杆菌、肺炎链球菌及卡他莫拉菌在下呼吸道感染患儿痰液中年分离率分别为1.7%～8.9%、1.1%～5.9%和0.7%～4.7%，3种致病菌分离率变化不明显（P＞0.05），其中流感嗜血杆菌年分离率明显高于卡他莫拉菌（P=0.026）。痰液标本中未分离到化脓性链球菌。流感嗜血杆菌对氨苄西林耐药率为15.0%～.30.0%，上升趋势不显著（P=0.4），对头孢克罗耐药率为2.5%～11.2%，增加趋势明显（P=0.005）。青霉素高度耐药肺炎链球菌为4.2%～27.3%，低度耐药株为35.0%～61.2%，两者增加趋势显著（P<0.05）。化脓性链球菌对青霉素仍高度敏感，红霉素耐药率高达85%以上。卡他莫菌β-内酰胺类阳性率在95%左右。结论 化脓性链球菌是上呼吸道细菌感染的首要致病菌，分离率呈上升趋势，绝大多数已对红霉素耐药。流感嗜血杆菌、肺炎链球菌和卡他莫拉菌在下呼吸道感染患儿痰液标本中分离率变化不明显，其中流感嗜血杆菌对头孢克罗及肺炎链球菌对青霉素的耐药率呈明显增加趋势。     

Influence of child care on nasopharyngeal carriage of Streptococcus pneumoniae and Haemophilus influenzae

BACKGROUND: Children cared for by a child minder (CM) should be less exposed to upper respiratory tract infections than those in group day care (GDC) and therefore to antibiotic treatment. Thus fewer CM children should carry resistant bacteria. To test this hypothesis nasopharyngeal carriage of Streptococcus pneumoniae (SP) and Haemophilus influenzae (HI) and exposure to recent antibiotic treatment were investigated among children in both types of care settings in the Alpes Maritimes (France) between November 1999 and March 2000. METHODS AND POPULATION: A two stage cluster sample of children attending group day care or cared for by a child minder was selected. Nasopharyngeal samples were cultured for SP and HI. Penicillin susceptibility was tested by disk diffusion and E-test and beta-lactamase production. RESULTS: We sampled 235 children in the CM group and 298 in the GDC group who were ages 6 to 36 months. Age and sex distribution were similar in both groups. S. pneumoniae was isolated in 80 children in the CM group (34.0%) and in 163 (54.7%) children in GDC (P < 10-6). Proportions of non-penicillin susceptible (NPSP) were 52.5 and 55.8%, respectively (P = 0.6). H. influenzae was present in 37.2% of children in GDC vs. 23.8% in the CM group (P < 0.001). Proportions of beta-lactamase-positive HI (HIBL+) were 40.2% vs. 46.4%, respectively (P = 0.4). Antibiotic exposure during the previous 3 months occurred in 41.3% of children in GDC and in 47.4% in the CM group (P = 0.16). There was no association between antibiotic use and carriage of NPSP or HIBL+ strains. CONCLUSION: SP and HI carriage rates were significantly lower among children in the CM group than in GDC. The proportion of NPSP and HIBL+ was similar in both groups, and comparable patterns of antibiotic use were observed. Continued efforts must concentrate on parental education and enforcement of recommendations for management of pediatric upper respiratory tract infections.     

Antibiotic resistance in Streptococcus pneumoniae isolated from children

OBJECTIVE: To determine the level of antibiotic resistance in pneumoniae (S. pneumoniae) isolated from nasal swabs of healthy children. METHOD: Cross-sectional community survey. SETTING: Survey was undertaken in general practice settings in Canberra during March and April 1998. SUBJECTS: Four hundred and sixty-one children under 3 years of age enrolled in general practice trial of clinical practice guidelines for antibiotic use. OUTCOME MEASURES: Resistance to penicillin, erythromycin, co-trimoxazole, tetracycline, chloramphenicol and cefotaxime among the isolates of S. pneumoniae. RESULTS: A total of 461 nasal swabs were collected and S. pneumoniae was isolated from 171 (37.1%). Penicillin resistance was found in 12.3% of these isolates, with high level resistance in 0.6%. Resistance rates were higher for cotrimoxazole (44.4%) and erythromycin (18.1%) than for penicillin. Multidrug resistance was found in 19% of these isolates. There was a significant association between the attendance at a day care centre and carriage of pneumococcus (53% vs 32%, odds ratio (OR) 2.4, 95% confidence interval (CI) 1.5-3.7, P < 0.001). Children who attended day care centers and had received antibiotics during the 4 months prior to swab collection were three times more likely to carry an antibiotic-resistant isolate than children who had neither attended a day care centre nor received antibiotics (68% vs 40%, OR 3.1, 95% CI 1.2-8.4, P = 0.02). CONCLUSION: The level of antibiotic resistance in pneumococci from healthy children was of concern. Carriage of pneumococcus was significantly higher in children who attended a day care centre. Resistance was significantly correlated with antibiotic use in combination with day-care attendance. These findings warrant more judicious use of antibiotics in children.