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.     

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.     

2006至2009年复旦大学附属儿科医院呼吸道感染患儿5种常见细菌构成比和耐药性分析

目的 了解复旦大学附属儿科医院4年中呼吸道感染患儿呼吸道标本中化脓性链球菌、肺炎链球菌、金黄色葡萄球菌、流感嗜血杆菌和卡他莫拉菌耐药率变化。方法 以2006至2009年在复旦大学附属儿科医院诊断为呼吸道感染的患儿为研究对象,采集咽拭子或痰标本行细菌培养。细菌鉴定采用NCCLS/CLSI 2006至2009年标准及英国BSAC标准。采用琼脂扩散法（KB）对5种常见细菌进行药物敏感实验,结果参照CLSI 2006至2009年标准,肺炎链球菌青霉素药物敏感实验采用E-test检测。结果 2006至2009年呼吸道标本中共分离到细菌3 169株,其中化脓性链球菌1 225株、肺炎链球菌341株、金黄色葡萄球菌297株、流感嗜血杆菌248株、卡他莫拉菌237株。①化脓性链球菌在上呼吸道细菌中构成比为74.5％~78.8％,流感嗜血杆菌和卡他莫拉菌在上下呼吸道细菌中的构成比有逐年上升趋势（P<0.05）。②2006至2009年,化脓性链球菌对红霉素耐药率为86.8％～94.7％,未发现青霉素耐药株;青霉素不敏感肺炎链球菌比例为1.4％~20.8％,4年间差异有统计学意义（P=0.007）,肺炎链球菌对红霉素耐药率为91.1％~97.9％;金黄色葡萄球菌对红霉素耐药率为50.0％~54.9％,耐甲氧西林金黄色葡萄球菌比例为7.7％~11.4％;上述3种细菌对万古霉素均敏感。流感嗜血杆菌和卡他莫拉菌β-内酰胺酶阳性率分别为17.0％~31.3％和83.1％~100％,流感嗜血杆菌对头孢呋辛耐药率较低,卡他莫拉菌对环丙沙星和阿莫西林/克拉维酸高度敏感。结论 化脓性链球菌和肺炎链球菌对青霉素高度敏感。化脓性链球菌、肺炎链球菌及金黄色葡萄球菌对红霉素高度耐药。产酶的流感嗜血杆菌对第2代头孢菌素高度敏感,卡他莫拉菌对喹诺酮类和酶抑制剂复合制剂高度敏感。     

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).     

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.     

Bacteriologic and clinical efficacy of high dose amoxicillin/clavulanate in children with acute otitis media.

OBJECTIVES: To determine the bacteriologic and clinical efficacy of high dose amoxicillin/clavulanate (90/6.4 mg/kg/day) against common bacterial pathogens causing acute otitis media (AOM), including penicillin-resistant Streptococcus pneumoniae (PRSP). METHODS: In this open label multicenter study, 521 infants and children with AOM [mean age, 18.6 months; age < 24 months, n = 375 (72%)] were treated with amoxicillin/clavulanate 90/6.4 mg/kg/day in two divided doses for 10 days. Bilateral otitis media, previous episodes of AOM, antibiotic treatment within 3 months and day-care attendance were recorded in 60.1, 35.7, 50.2 and 38.2% of the children, respectively. Tympanocentesis was performed before the first dose and repeated on Days 4 to 6 for all children with S. pneumoniae at 22 centers and for all children with any pathogen at 3 centers. Clinical response was assessed at end of therapy. RESULTS: Pathogens were isolated from 355 (68%) of 521 enrolled children; 180 children underwent repeat tympanocentesis and were bacteriologically evaluable. Baseline pathogens were S. pneumoniae (n = 122 enrolled/93 bacteriologically evaluable), Haemophilus influenzae (n = 160/51), both (n = 37/32) and others (n = 36/4). Pathogens were eradicated from 172 (96%) of 180 bacteriologically evaluable children. Overall 122 (98%) of 125 isolates of S. pneumoniae were eradicated, including 31 (91%) of 34 PRSP isolates (penicillin MICs 2 to 4 micrograms/ml). Seventy-eight (94%) of 83 isolates of H. influenzae were eradicated. Symptoms and otoscopic signs of acute inflammation were completely resolved or improved on Days 12 to 15 in 263 (89%) of 295 clinically evaluable children with bacteriologically documented AOM. CONCLUSIONS: On the basis of bacteriologic outcome on Days 4 to 6 and clinical outcome on Days 12 to 15, we found that high dose amoxicillin/clavulanate (90/6.4 mg/kg/day) was highly efficacious in children with AOM, including those most likely to fail treatment, namely children < 24 months of age and those with infectious caused by PRSP.     

Antibiotic-resistant bacteria in pediatric chronic sinusitis

BACKGROUND: Limited information exists on emerging bacterial resistance patterns in pediatric chronic sinusitis. METHODS: A retrospective review (1995 to 1998) of the aerobic microbiology of chronic sinusitis in children at a tertiary care children's hospital was conducted. One hundred nineteen children (mean age, 4.9 years) with maxillary sinusitis of >8 weeks duration and no known immunodeficiency or cystic fibrosis who underwent antral irrigation were included. RESULTS: One hundred sixty-one of 240 (67%) aerobic cultures were positive, yielding 274 isolates. Eighty-eight positive cultures were polymicrobial. The most frequent isolates were nontypable Haemophilus influenzae (24%), Streptococcus pneumoniae (19%), Moraxella catarrhalis (17%), coagulase-negative Staphylococcus (6%), alpha-streptococci (6%), diphtheroids (5%), Staphylococcus aureus (3%) and Neisseria spp. (3%). Rates of nonsusceptibility of Streptococcus pneumoniae were 64% for penicillin (24% high grade resistance), 40% for cefotaxime, 18% for clindamycin and 0% for vancomycin. Rates of nonsusceptibility of S. pneumoniae did not change significantly during the study period. Thirty-nine percent of H. influenzae isolates were beta-lactamase-positive and 44% were nonsusceptible to ampicillin (41% high grade resistance). Beta-lactamase positivity of H. influenzae decreased during the study period (P = 0.06). All M. catarrhalis isolates tested were beta-lactamase-positive. CONCLUSION: This study indicates that the aerobic pathogens in pediatric chronic sinusitis include bacteria typical of acute sinusitis as well as organisms more characteristic of chronic disease. Moreover it highlights the significant role of antibiotic-resistant aerobes, including multiply resistant S. pneumoniae, in pediatric chronic sinusitis.     

头孢地尼对儿科呼吸道常见致病菌体外抗菌活性的研究

目的探讨头孢地尼对小儿呼吸道常见致病菌的体外抗菌活性。方法E-test法测定头孢地尼对肺炎链球菌等7种细菌共380株的最低抑菌浓度(MIC),并与头孢克洛作对比研究。结果青霉素敏感肺炎链球菌(PSSP)对头孢地尼和头孢克洛均敏感,青霉素耐药肺炎链球菌(PRSP)均耐药,青霉素中介肺炎链球菌(PISP)对头孢地尼敏感率72．0％,头孢克洛为58．0％。不产β内酰胺酶的流感嗜血杆菌(HI)对两者均敏感,但对产β内酰胺酶HI,头孢地尼敏感率85．0％、头孢克洛70．0％,MIC90值头孢地尼(1．5mg/L)明显低于头孢克洛(256．0mg/L)。卡他莫拉菌(MC)、A组链球菌(GAS)和甲氧西林敏感的金黄色葡萄球菌(MSSA),以及不产超广谱B内酰胺酶(ESBLs)的大肠埃希菌(E．coli)、肺炎克雷伯菌(k.pn),对头孢地尼抗菌活性均优于头孢克洛。对产ESBLs的菌株,两者均无抗菌活性。结论头孢地尼对PSSP、PISP、HI、GAS、MC、MSSA以及ESBLs(-)k.pn和E．coli均有强大的体外抗菌活性。     

儿童社区获得性肺炎病原微生物分布特点分析

目的：了解儿童社区获得性肺炎（CAP）病原微生物分布规律,为临床诊断和合理用药提供依据。方法：1560例年龄在1个月至9岁间的CAP患儿于入院2 h内、抗感染药物治疗前分别采集呼吸道分泌物和静脉血进行多病原联合检测。免疫荧光法检测鼻咽拭子标本中呼吸道病毒抗原,痰液用于行细菌培养,ELISA法检测静脉血中肺炎支原体及肺炎衣原体IgM。结果：在1560例CAP患儿中,痰培养细菌579株,其中革兰阳性菌213株（36.8%）,革兰阴性菌366株（63.2%）;检出前5位的细菌包括流感嗜血杆菌（7.50%）、肺炎链球菌（6.73%）、金黄色葡萄球菌（6.35%）、卡他莫拉菌（5.19%）和大肠埃希氏菌（3.46%）,前5位细菌中产酶菌占检出全部细菌的3.3%。其他病原体感染中,呼吸道合胞病毒感染率最高,为12.88%,其次为肺炎支原体（7.88%）和肺炎衣原体（8.91%）。混合感染严重,其中呼吸道合胞病毒与流感嗜血杆菌混合感染最为常见。多数病原微生物在1岁以下患儿中的感染率高于1岁以上患儿。结论：流感嗜血杆菌、呼吸道合胞病毒、肺炎支原体、肺炎衣原体为儿童CAP的主要病原体,多数病原微生物在1岁以下患儿中感染率高于1岁以上患儿,多种病原菌混合感染率高。     

Intermediate resistance of Streptococcus pneumoniae to penicillin in children in day-care centers.

This study was performed to determine the prevalence, serotypes and antibiotic susceptibility patterns of penicillin-resistant Streptococcus pneumoniae in children younger than 3 years of age in day-care centers in Houston, TX. Nasopharyngeal cultures were obtained on two occasions, in March and May, 1989, from 140 children in 4 day-care centers. All penicillin-resistant S. pneumoniae organisms isolated in this study had minimum inhibitory concentrations to penicillin of between 0.1 and 0.5 microgram/ml and were thus intermediately resistant. No highly resistant S. pneumoniae (minimum inhibitory concentration > or = 1.0 microgram/ml) was isolated in this study. Nasal carriage of S. pneumoniae occurred in 39% of children; carriage of intermediately resistant S. pneumoniae occurred in 4% of children. Of the 39% of children who carried S. pneumoniae, 11% carried intermediately resistant strains. In one day-care center with a prior history of intermediately resistant S. pneumoniae (Center 1), the prevalence of intermediate penicillin resistance was significantly (P = 0.047) higher than in the other three centers. Among children surveyed twice 15% of Center 1 children carried an intermediately penicillin-resistant strain at least once, whereas in the other centers 3% of children carried an intermediately resistant strain at least once. Sixty-two percent of intermediately penicillin-resistant strains were resistant to multiple antibiotics and all were serotype 14. Intermediately penicillin-resistant S. pneumoniae isolates were prevalent among young children in day-care centers in Houston and may persist in some day-care centers and become endemic.     

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。     

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.     

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。     

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。     

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.     

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]     

Diversity and sharing of Haemophilus influenzae strains colonizing healthy children attending day-care centers

BACKGROUND: Children attending day-care centers (DCCs) are at risk for Haemophilus influenzae nasopharyngeal colonization and acute otitis media. The degree to which a given strain circulates within a day-care center and the heterogeneity of strains among DCCs in a geographic area are not well-characterized. This study describes the prevalence rates of H. influenzae colonization in a large number of children attending day-care centers and examines the genetic diversity of colonizing strains and the degree of sharing among children. METHODS: Throat cultures were collected from 198 healthy children <3 years old attending 16 day-care centers in Michigan. All H. influenzae isolates were genetically typed by enterobacterial repetitive intergenic consensus PCR as the initial screening technique to identify unique strains within each child. Pulsed field gel electrophoresis was used subsequently to examine the genetic diversity of strains between children. RESULTS: There were 127 (64%) children colonized with H. influenzae. Wide variation in rates of colonization was identified among day-care centers (0 to 95%). A total of 179 genetically unique H. influenzae strains were isolated, and 47 children (37%) were colonized with 2 or more genetically distinct H. influenzae organisms. Evidence of sharing of the same strain in different children was found in 13 of 15 colonized DCCs and 23% of genotypically unique strains were shared. CONCLUSION: The degree of sharing of H. influenzae among children in this study suggests transmission of these potentially pathogenic microorganisms in day-care centers.     

Streptococcus pneumoniae and Haemophilus influenzae at the initial stage of influenza

Background:  Streptococcus pneumoniae and Haemophilus influenzae infections in children with influenza have been noted because of the severity of co-infection. In Japan, vaccination against S. pneumoniae and H. influenzae infections has been listed in the vaccine program in 2008, but the characteristics of the two organisms, colonizing at the initial stage of influenza infection, have not been investigated in detail.
Methods:  Nasopharyngeal swabs from children with influenza (flu⁺) ( n = 236; mean age, 6.2 years) were examined for bacterial pathogens, including S. pneumoniae and H. influenzae . They were then examined for serotypes, drug susceptibilities, and resistance genes (or gene mutations). As a reference, children with upper respiratory tract infection (URTI⁺, flu^-; n = 189; mean age, 6.2 years) were also examined.
Results:  S. pneumoniae , β-streptococci (groups A, B, and G), methicillin-susceptible and -resistant S. aureus , Moraxella catarrhalis , and H. influenzae were isolated. For S. pneumoniae , nine serotypes were detected with prevalent types of 3, 6, 19 and 23. Penicillin resistance was detected in types 19 and 23, while resistance to macrolide and clindamycin was found in various types. For H. influenzae , only b serotype was detected, with marked ampicillin resistance. The majority was non-typeable. Very similar results were obtained even in URTI⁺ (flu^-) cases.
Conclusion:  Multiple drug-resistant S. pneumoniae with major serotypes, for example, 19 and 23 and H. influenzae with serotype b were already present at the initial stage of influenza infection, similar to URTI⁺ flu^- cases. They could be prevented by current vaccines, but drug-resistant non-typeable H. influenzae is troubling.     

5岁以下儿童门诊呼吸道感染常见病原携带及抗生素耐药的流行病学特征调查

目的　了解 5岁以下儿童呼吸道感染肺炎链球菌 (SP)、流感嗜血杆菌 (HI)、卡他莫拉菌 (M .Cat)携带株的流行病学特征、耐药情况及其影响因素。方法　对 2 0 0 0年 1月至 2 0 0 3年 5月在北京儿童医院内科门诊就诊的≤ 5岁呼吸道感染儿童进行随机选择问卷调查 ;采鼻咽拭子标本 ;培养、分离、鉴定SP、HI,其中对 2 0 0 2年 1月至 2 0 0 3年 5月的标本同时进行了M .Cat的分离 ;用E test、K B法检测SP、HI对抗生素的敏感性 ,用琼脂扩散法检测M .Cat的药物敏感性 ;评价年龄、居住地、入托、抗生素使用、诊断对病原携带及其耐药株的影响。结果　本文≤ 5岁儿童呼吸道感染SP、HI、M .Cat的携带率分别为 2 8 6%、2 8 3%、1 5 8%。SP青霉素耐药率为 2 3 3% ,HI氨苄青霉素的耐药率为 1 0 2 % ,M .Cat对氨苄青霉素的耐药率高达 90 3%。影响病原携带、抗生素耐药的主要因素有年龄、入托、抗生素使用。结论　≤ 5岁儿童呼吸道感染携带病原菌株耐药率快速上升 ,抗生素使耐药菌株携带率增高 ,因而合理使用抗生素非常重要。