Hospitalization of Jewish and Bedouin infants in southern Israel for bronchiolitis caused by respiratory syncytial virus

Incidence and risk factors of hospitalisations for respiratory syncytial virus among children aged less than two years

The study aim was to examine the incidence and risk factors of respiratory syncytial virus (RSV) bronchiolitis hospitalisations and disease severity among infants. We compared demographic and health characteristics of children aged 0–23 hospitalised for RSV bronchiolitis (cases, n = 1227) during 2008–2018 and control children (n = 554) of the same age admitted for non-respiratory disease. RSV antigen was detected in nasal swabs by immunochromatography. Multiple logistic regression models were applied. The average annual incidence of hospitalisation for RSV bronchiolitis was 12.6 per 1000 and 1.7 per 1000 (P < 0.001) among infants and toddlers, respectively, with winter seasonality (November–March). The risk of hospitalisation for RSV bronchiolitis increased among children aged 0–5 months (OR 7.66; 95% CI 5.61–10.45) and 6–11 months (OR 12.88, 95% CI 8.48–19.55), compared to those aged 12–23 months. Additional risk factors were living in low vs. higher socio-economic status towns (OR 1.49; 95% CI 1.14–1.95), having chronic medical conditions (OR 2.75; 95% CI 1.61–4.70), birth month (October–January vs. June–September) (OR 2.19; 95% CI 1.60–2.99) and history of stay in neonatal intensive care unit at birth (OR 2.37; 95% CI 1.27–4.41). Male children and those who had pneumonia were more likely to have severe RSV bronchiolitis. In conclusion, the burden of hospitalisations for RSV bronchiolitis is high, especially in young infants. Effective preventive measures such as RSV active vaccines can reduce the risk of hospitalisations for RSV bronchiolitis among these vulnerable groups.

Unnecessary antibiotic treatment of children hospitalised with respiratory syncytial virus (RSV) bronchiolitis: risk factors and prescription patterns

OBJECTIVES

Respiratory syncytial virus (RSV) is a leading cause of respiratory tract infections, especially in young children. Antibiotics are often unnecessarily prescribed for the treatment of RSV. Such treatments affect antibiotic resistance in future bacterial infections of treated patients and the general population. This study aimed to understand risk factors for and patterns of unnecessary antibiotic prescription in children with RSV.

METHODS

In a single-centre, retrospective study in Israel, we obtained data for children aged ≤2 years (n = 1016) hospitalised for RSV bronchiolitis during 2008-2018 and ascertained not to have bacterial co-infections. Antibiotic misuse was defined as prescription of antibiotics during hospitalisation of the study population. Demographic and clinical variables were assessed as predictors of unnecessary antibiotic treatment in a multivariable logistic regression model.

RESULTS

The unnecessary antibiotic treatment rate of children infected with RSV and ascertained not to have a bacterial co-infection was estimated at 33.4% (95% CI 30.5-36.4%). An increased likelihood of antibiotic misuse was associated with drawing bacterial cultures and with variables indicative of a severe patient status such as lower oxygen saturation, higher body temperature, tachypnoea and prior recent emergency room visit. Older age and female sex were also associated with an increased likelihood of unnecessary antibiotic treatment.

CONCLUSIONS

Unnecessary antibiotic treatment in RSV patients was very common and may be largely attributed to physicians' perception of patients' severity. Improving prescription guidelines, implementing antibiotic stewardship programmes and utilising decision support systems may help achieve a better balance between prescribing and withholding antibiotic treatment.

Characterization of children younger than 5 Years of age with severe community-acquired alveolar pneumonia (CAAP) requiring Pediatric Intensive Care Unit (PICU) admission

BACKGROUND

The purpose of this study was to determine factors characterizing children admitted to the Pediatric Intensive Care Unit (PICU) with community-acquired alveolar pneumonia (CAAP) to help clinicians assess disease severity upon initial assessment in the emergency department.

METHODS

We prospectively collected demographic, clinical, and laboratory data of children <5 years with radiologically confirmed CAAP referred to the Soroka University Medical Center during 2001-2011. Three groups of children were compared: 1) those hospitalized in the PICU (PICU-CAAP); 2) those treated in the emergency department and discharged (ED-CAAP); and 3) those hospitalized in a pediatric ward (Hosp-CAAP).

RESULTS

Of 9722 CAAP episodes, 367 (3.8%) were PICU-CAAP, 5552 (57.1%) Hosp-CAAP and 3803 (39.1%) ED-CAAP. In a univariate analysis, respiratory syncytial virus (RSV) was detected more commonly among PICU-CAAP than in Hosp-CAAP (P = 0.02) and ED-CAAP patients (P < 0.001). In a multivariate analysis, several factors were associated with PICU hospitalization versus ED-CAAP and Hosp-CAAP: Younger age (ORs: 1.04, [95%CI: 1.02-1.05] and 0.97 [0.96-0.98], respectively); prematurity (ORs: 2.16 [1.28-3.64] and 1.61 [1.15-2.26], respectively), lower O₂ saturation (ORs: 1.32 [1.25-1.41] and 0.94[0.92-0.96]), higher respiratory rate (ORs: 1.06 [1.04-1.07] and 1.00 [1-1.01], respectively).

CONCLUSION

Children admitted to PICU were younger, had more respiratory syncytial virus (RSV) detection, were premature, had lower O₂ saturation, and had a higher respiratory rate than those admitted to the general ward or those visiting the emergency department and subsequently discharged.

Quantification and Characterization of Antimicrobial Resistance in Greywater Discharged to the Environment

In disenfranchised communities, untreated greywater (wastewater without sewage) is often environmentally discharged, resulting in potential human exposure to antimicrobial-resistant bacteria (ARB), including extended-spectrum beta-lactamase (ESBL) producers. We sought to examine the abundance of ARB, specifically ESBLs, and antimicrobial resistance genes (ARGs) in greywater from off-grid, pastoral Bedouin villages in Southern Israel. Greywater samples (n = 21) collected from five villages were analyzed to enumerate fecal coliforms and Escherichia coli. ESBL producers were recovered on CHROMagar ESBL and confirmed by VITEK®2 (bioMerieux, Marcy l’Etoile, France) for identification and antimicrobial susceptibility testing. Total genomic DNA was extracted from greywater samples and quantitative PCR (qPCR) was used to determine relative abundance (gene copies/16S rRNA gene) of class 1 integron-integrase intI1, blaTEM, blaCTX-M-32, sul1, and qnrS. The mean count of presumptive ESBL-producing isolates was 4.5 × 106 CFU/100 mL. Of 81 presumptive isolates, 15 ESBL producers were recovered. Phenotypically, 86.7% of ESBL producers were multi-drug resistant. Results from qPCR revealed a high abundance of intI1 (1.4 × 10−1 gene copies/16S rRNA), sul1 (5.2 × 10−2 gene copies/16S rRNA), and qnrS (1.7 × 10−2 gene copies/16S rRNA) followed by blaTEM (3.5 × 10−3 gene copies/16S rRNA) and blaCTX-M-32 (2.2 × 10−5 gene copies/16S rRNA). Results from our study indicate that greywater can be a source of ARB, including ESBL producers, in settings characterized by low sanitary conditions and inadequate wastewater management.

Comparisons between ethnic groups in hospitalizations for respiratory syncytial virus bronchiolitis in Israel

BACKGROUND

Ethnic disparities have been shown in respiratory syncytial virus (RSV) bronchiolitis. However, it is unclear whether such differences are related to access to care. We compared demographic and clinical characteristics of Arab and Jewish children hospitalized for RSV bronchiolitis in Israel, a country with universal health insurance.

METHODS

We reviewed the medical records of all children (n = 309) aged less than 24 months who were hospitalized with RSV between 2008 and 2011 in one medical center in Israel. Demographic, clinical, laboratory and radiological data were collected. The RSV antigen was identified using immunochromatography.

RESULTS

The annual incidence of RSV hospitalization was 5.4/1000 and 6.8/1000 among Arab and Jewish children, respectively. Arab patients were significantly younger and had significantly younger parents; most lived in low socioeconomic status towns (93.7% vs. 13.3%; p<0.001) and had more siblings (median 2 vs. 1; p = 0.01) compared to Jewish patients. Disease severity did not differ between the two ethnic groups (p = 0.3). The main predictors of severe illness were having pneumonia (adjusted odds ratio [OR] 3.86; 95% confidence intervals [CI] 1.87-7.97) and history of respiratory diseases (adjusted OR 3.89; 95% CI 1.22-12.38).

CONCLUSIONS

The incidence of hospitalizations for RSV bronchiolitis tended to be higher among Jewish than Arab children, possibly due to differences in health care utilization patterns. Differences between the Jewish and Arab patients in demographic factors likely mirror differences between the groups in the general population. Pneumonia, and not ethnicity, affected the severity of RSV bronchiolitis.

Air Pollution and Hospitalization for Bronchiolitis among Young Children

RATIONAL

Several studies have found higher risks for childhood respiratory illness, associated with exposure to particulate matter (PM) less than 10 μm in diameter (PM₁₀) and PM_2.5 and gaseous pollution.

OBJECTIVES

We analyzed the association between air pollution and hospitalizations due to bronchiolitis, an obstructive pulmonary disorder, commonly caused by respiratory syncytial virus infant infection.

METHODS

Data were obtained from a local tertiary medical center providing services for a population of 700,000 comprising two ethnic groups: predominantly urban Jews and rural Bedouin Arabs. The latter group includes 30% residing in unrecognized villages in a temporary dwelling. We included all infants (0-2 yr) hospitalized with bronchiolitis between 2003 and 2013. Daily PM estimates were obtained from a satellite-based model incorporating daily remote sensing data and assigned to the family residence locality. Other air pollutants and meteorological parameters were obtained from a local monitoring site. We used case-crossover models with adjustment for temperature.

RESULTS

We identified 4,069 bronchiolitis hospitalizations (3,889 children), with 55.3% being Bedouin Arabs, of whom 16.8% resided in temporary dwellings. An increase in interquartile range of average weekly air pollutants was associated with an increased odds of bronchiolitis (odds ratio [95% confidence interval]): PM₁₀ (1.06 [1.02-1.09]), PM_2.5 (1.04 [1.02-1.06]) and nitrogen dioxide (1.36 [1.12-1.65]). Higher effect-estimates for PM were observed among Bedouin Arabs residing in temporary dwellings (1.14 [1.01-1.30] and 1.07 [1.01-1.15]) compared with Jewish individuals (1.05 [0.99-1.11] and 1.03 [1.01-1.07]) and other Bedouin Arabs (1.05 [1.01-1.10] and 1.03 [1.01-1.07]), and among males (1.11 [1.06-1.16] and 1.06 [1.03-1.09]) compared with females (0.99 [0.94-1.05] and 1.01 [0.97-1.04]).

CONCLUSIONS

High PM levels were positively associated with bronchiolitis. The stronger associations among Bedouin Arabs may be related to higher pollution infiltration and exposure in residents of temporary dwellings.

Differential impact of pneumococcal conjugate vaccines on bacteremic pneumonia versus other invasive pneumococcal disease

BACKGROUND

Bacteremic pneumonia (BP) accounts for ~35% of invasive pneumococcal disease (IPD) in young children. Our aims were to compare age, seasonal and serotype distribution of BP versus non-BP IPD and to determine whether the impact of the sequential 7/13-valent pneumococcal conjugate vaccine (PCV7/PCV13) introduction on disease incidence differed between BP and non-BP IPD in children <5 years of age.

METHODS

A nationwide, prospective, population-based, active surveillance (July 2004-June 2013) was conducted. All IPD episodes were included. PCV7 was introduced to the Israeli National Immunization Plan in July 2009 and has been replaced by PCV13 since November 2010.

RESULTS

In all, 983 (36.8%) BP and 1687 (63.2%) non-BP IPD episodes were recorded. A higher proportion of BP than that of non-BP IPD episodes (42.0% vs. 20.7%; P < 0.001) occurred in children >24 months old. Seasonality differed between BP and non-BP IPD, with yearly earlier peaks of non-BP IPD. The proportion of the 5 additional PCV13 serotypes (1, 3, 5, 7F and 19A) was higher in children with BP versus non-BP IPD (39.6% vs. 23.6%; P < 0.01). Shortly after PCV7 introduction, non-BP IPD rate was significantly reduced but that of BP was not. However, PCV13 introduction resulted in rapid reduction of BP rate, with a further reduction of non-BP IPD.

CONCLUSION

The differences in age distribution, seasonality and serotype distribution between BP and non-BP IPD suggest that the pathogenesis of these 2 entities is not identical and resulted in different impact rate dynamics after PCV7 and PCV13 introduction.

Early impact of sequential introduction of 7-valent and 13-valent pneumococcal conjugate vaccine on IPD in Israeli children <5 years: an active prospective nationwide surveillance

BACKGROUND

The 7-valent pneumococcal conjugated vaccine (PCV7) was introduced to the Israeli national immunization plan (NIP) in July 2009 (administered at age 2, 4 and 12 months), with a fast reduction of invasive pneumococcal disease (IPD) caused by PCV7 serotypes. Starting in November 2010, PCV13 gradually replaced PCV7.

AIM

To report the impact of PCV7/PCV13 sequential introduction on IPD in Israeli children <5 years.

METHODS

An ongoing nationwide, prospective, population-based, active surveillance. All IPD episodes (Streptococcus pneumoniae isolated from blood and/or cerebrospinal fluid) from July 2004 through June 2013 were included.

RESULTS

Overall, 2670 IPD episodes were recorded. Incidence of IPD caused by PCV7+6A serotypes during the PCV13 period vs. pre-PCV period decreased by 95% (Incidence Rate Ratio [IRR]=0.05; 95% CI=0.03-0.09). This reduction was observed in a two-step manner: 90% in the PCV7-period and further 5% in the PCV13-period. The rates of IPD caused by the 5 additional PCV13-serotypes (1, 3, 5, 7F, 19A; 5VT) increased initially by 47%, but subsequently decreased by 79%, resulting in an overall 70% reduction during the entire study period (IRR=0.30; 0.21-0.44). A two-fold increase in non-PCV13 serotypes IPD was observed (IRR=2.43; 1.73-3.66). In total, a 63% reduction of all-serotype IPD episodes was observed in children <5 years (69% and 48% in children <2 and 2-4 years old, respectively).

CONCLUSIONS

After initiation of PCV NIP, a rapid and substantial 2-step IPD reduction was observed in children <5 years. The serotype-specific rate reduction reflected the sequential introduction of PCV7/PCV13.

Rapid reduction in invasive pneumococcal disease after introduction of PCV7 into the National Immunization Plan in Israel

BACKGROUND

The 7-valent conjugated vaccine (PCV7) was introduced into the Israeli National Immunization Program (NIP) in July 2009 (2, 4, 12 months schedule; 2 dose catch-up in second year of life). Nationwide active prospective surveillance on invasive pneumococcal disease (IPD) has been conducted in children since 1989. In the current study, IPD epidemiology in children <5 years during the 20 years before and 18 months after PCV7 NIP initiation, is reported.

METHODS

All 27 centers performing blood/cerebrospinal fluid (CSF) cultures in children reported monthly IPD cases. Capture-recapture approach was used for completeness.

RESULTS

During 1989-2010, 6022 IPD cases were reported in children <5 years; PCV7 serotypes (7VST) caused ∼50% of all episodes. In 2009 and 2010, 7VST IPD incidences <5 years of age (per 100,000) were 15.9 and 5.4, respectively (a 43% and 81% decrease, respectively) compared to 2003-2007 (mean incidence 27.8). Serotype 6A dynamics resembled those of 7VST. The respective overall IPD incidence decreases were 23% and 42%. The incidence dynamics of serotypes 1, 3, 5, 7F and 19A IPD were characterized by considerable fluctuations over the study period without any upwards or downwards trend in any of the age groups. The overall incidence of serotypes not included in the 13-valent pneumococcal conjugate vaccine (PCV13) did not vary significantly during the study period. By the end of 2010, 72% of the remaining IPD was caused by pneumococcal serotypes included in PCV13.

CONCLUSIONS

An active prospective long-term surveillance, showed a rapid and sharp decline in IPD in children <5 years following initiation of NIP with PCV7. No serotype replacement has been observed so far. The transition from PCV7 to PCV13 initiated in October 2010 may lead to a further substantial decrease in IPD. Follow-up is needed to better determine the long-term PCV effects.

Viral etiology of severe pneumonia among Kenyan infants and children

CONTEXT

Pneumonia is the leading cause of childhood death in sub-Saharan Africa. Comparative estimates of the contribution of causative pathogens to the burden of disease are essential for targeted vaccine development.

OBJECTIVE

To determine the viral etiology of severe pneumonia among infants and children at a rural Kenyan hospital using comprehensive and sensitive molecular diagnostic techniques.

DESIGN, SETTING, AND PARTICIPANTS

Prospective observational and case-control study during 2007 in a rural Kenyan district hospital. Participants were children aged 1 day to 12 years, residing in a systematically enumerated catchment area, and who either were admitted to Kilifi District Hospital meeting World Health Organization clinical criteria for severe pneumonia or very severe pneumonia; (2) presented with mild upper respiratory tract infection but were not admitted; or (3) were well infants and children attending for immunization.

MAIN OUTCOME MEASURES

The presence of respiratory viruses and the odds ratio for admission with severe disease.

RESULTS

Of 922 eligible admitted patients, 759 were sampled (82% [median age, 9 months]). One or more respiratory viruses were detected in 425 of the 759 sampled (56% [95% confidence interval {CI}, 52%-60%]). Respiratory syncytial virus (RSV) was detected in 260 participants (34% [95% CI, 31%-38%]) and other respiratory viruses were detected in 219 participants (29%; 95% CI, 26%-32%), the most common being Human coronavirus 229E (n = 51 [6.7%]), influenza type A (n = 44 [5.8%]), Parainfluenza type 3 (n = 29 [3.8%]), Human adenovirus (n = 29 [3.8%]), and Human metapneumovirus (n = 23 [3.0%]). Compared with well control participants, detection of RSV was associated with severe disease (5% [corrected] in control participants; adjusted odds ratio, 6.11 [95% CI, 1.65-22.6]) while collectively, other respiratory viruses were not associated with severe disease (23% in control participants; adjusted odds ratio, 1.27 [95% CI, 0.64-2.52]).

CONCLUSION

In a sample of Kenyan infants and children admitted with severe pneumonia to a rural hospital, RSV was the predominant viral pathogen.

Community-acquired bloodstream infections in children > one month old in southern Israel (1992–2001): Epidemiological, clinical and microbiological aspects

We studied the epidemiology, microbiology, clinical picture and outcome of community-acquired bloodstream infections (CABI) in children in southern Israel during 1992-2001. Information was collected prospectively by daily surveillance. CABI was diagnosed when a positive blood culture was reported in a patient discharged from the emergency room or during <48 h since admission if hospitalized. There were 1439 CABI episodes in 1396 children aged 1 month to 14 y. CABI incidence was 100/100,000 children with no increase during the study period. Risk of CABI was 3.8 times higher in a Bedouin than in a Jewish child. 1561 bacteria (793, 50%, gram-positive and 768, 49% gram-negative organisms, respectively) and 13 fungi were recovered. Most frequent gram-positive organisms were Streptococcus pneumoniae (509 isolates, 32% of all isolates, 64% of all gram-positive), Staphylococcus aureus (137, 9%, 17%) and Streptococcus pyogenes (46, 3%, 6%). Enterobacteriaceae spp. were the most frequent gram-negative pathogens (279, 18%, 36%), followed by Brucella (205, 13%, 27%). S. pneumoniae was the most common pathogen in children <12 months and 1-5 y age; Brucella was the most frequent pathogen in children >5 y of age. Coverage of 7-valent pneumococcal conjugated vaccine for CABI was 38.5%. 38 (2.7%) patients died; 16 cases were caused by S. pneumoniae.

Potential contribution by nontypable Haemophilus influenzae in protracted and recurrent acute otitis media

BACKGROUND

Characterization of acute otitis media (AOM) caused by nontypable Haemophilus influenzae (NTHi) is important, particularly in view of the efforts to develop vaccines against NTHi. To characterize NTHi AOM a large database of culture-positive AOM cases was analyzed.

METHODS

All culture-positive AOM episodes (NTHi, Streptococcus pneumoniae, Moraxella catarrhalis, and Streptococcus pyogenes) in children <5 years old from 1999 through 2006, processed in our center were included. One isolate was counted per episode (< or = 30 days). Demographic and clinical data were retrieved from charts or by telephone interviews. Multivariable regression analysis models were used.

RESULTS

Twelve thousand eight hundred twenty-three (8145 culture-positive) episodes were included. NTHi was recovered in 4928 episodes; S. pneumoniae in 4399 episodes, M. catarrhalis in 499, and S. pyogenes in 447 episodes. Independent risk factors for NTHi AOM (in culture-positive episodes) were: winter (odds ratio [OR]: 1.2, 95% confidence interval [CI]: 1.05-1.33, P = 0.006); bilateral AOM (OR: 1.26, 95% CI: 1.12-1.42, P < 0.001); >3 previous AOM episodes (OR: 1.27, 95% CI: 1.11-1.47, P = 0.001); and antibiotic consumption in previous month (OR: 1.3, 95% CI: 1.15-1.46, P < 0.001). ORs for these variables remained significant when the analysis was conducted on single-pathogen AOM only. For both NTHi and S. pneumoniae, risk factors for mixed episodes were older age and bilateral AOM.

CONCLUSION

NTHi AOM is characterized by higher occurrence in winter, bilaterality, recurrence, and previous antibiotic treatment compared with that caused by S. pneumoniae. These findings are in agreement with data associating NTHi with protracted or recurrent morbidity. The finding that S. pneumoniae and NTHi mixed episodes are more likely to occur in older children and in bilateral AOM suggests that interaction between these 2 pathogens contributes to chronicity or complexity of AOM.

Serotype coverage of invasive and mucosal pneumococcal disease in Israeli children younger than 3 years by various pneumococcal conjugate vaccines

BACKGROUND

: Since the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in the United States, the need for additional serotype coverage has become clear. Our objective was to assess the potential serotype coverage of PCV7 and of the 2 experimental conjugate vaccines, 10-valent (PCV10) and 13-valent (PCV13), against invasive pneumococcal disease (IPD), acute otitis media (AOM), acute conjunctivitis (AC), and pneumococcal carriage in southern Israel, where PCV7 had not yet been introduced at the time of the study.

METHODS

: Data on isolates were obtained prospectively from children <36 months during 2000-2004. The potential coverage of the PCVs was calculated and analyzed separately for antibiotic-resistant strains.

RESULTS

: A total of 5497 isolates were collected: 189 from blood or cerebrospinal fluid, 3197 from middle ear fluid, 348 from the conjunctiva, and 1763 from the nasopharynx of healthy children. The serotype coverage of PCV7 for IPD, AOM, AC, and carriage was 44%, 54%, 37%, and 46%, respectively. Serotypes included in PCV7 caused 47 IPD cases per 100,000 children <3 years (54 per 100,000 if serotype 6A is included). PCV10 extended mainly the coverage of IPD, while addition of serotypes 6A and 19A to PCV13 increased the coverage substantially in all entities (84%, 79%, 54%, and 67% in IPD, AOM, AC, and carriage, respectively). PCV13 could prevent >90% of penicillin-, macrolide-, and multidrug-resistant strains associated with IPD and AOM.

CONCLUSIONS

: PCV7 can substantially decrease pneumococcal disease and carriage in Israel, but PCV10 and PCV13 have a significant added benefit. Moreover, PCV13 has an important potential added benefit over PCV7 and PCV10 in reducing disease by drug-resistant Streptococcus pneumoniae.

The association between antibiotic use in the community and nasopharyngeal carriage of antibiotic-resistant Streptococcus pneumoniae in Bedouin children

BACKGROUND

The objective of the study was to evaluate whether the increase in antibiotic-resistant Streptococcus pneumoniae carriage was associated with antibiotic use in the community in children in Southern Israel.

METHODS

All the prescriptions given to Bedouin children <5 years old enlisted in 2 sentinel primary pediatric clinics treating approximately 20% of the Bedouin pediatric population of this age range were recorded, from 1998 to 2005. Nasopharyngeal pneumococcal isolates obtained during the same period from healthy children <5 years old were collected and antibiotic susceptibility was determined.

RESULTS

A total of 1488 of 1927 (77.7%) cultures were positive for S. pneumoniae. The proportion of S. pneumoniae with penicillin minimal inhibitory concentration > or = 1.0 microg/mL increased from 8% to 21% (P < 0.01); resistance to clindamycin from 9% to 22%; resistance to erythromycin from 13% to 30%; resistance to tetracycline from 13% to 31%; and multidrug resistance from 16% to 30%. The total annual antibiotic prescription rates decreased by 19%, from 3867 to 3191 prescriptions per 1000 children (P < 0.001). This was mainly the result of a reduction in amoxicillin +/- clavulanate prescriptions (from 3046 to 2582; P < 0.001). Oral cephalosporin, erythromycin and penicillin prescription rates decreased significantly as well (P < 0.001) whereas azithromycin prescription rates increased significantly (P < 0.001).

CONCLUSIONS

We suggest that the increased carriage of S. pneumoniae resistant to multiple antibiotics is possibly associated to the increased azithromycin consumption. Reduction of total antibiotic use may not be sufficient as long as antibiotics with high potential to promote multidrug resistance, given their pharmacokinetics and pharmacodynamics characteristics, are widely used.

Intussusception in children in Southern Israel: disparity between 2 populations

BACKGROUND

Intussusception has been associated with 1 rotavirus vaccine. Our objective was to determine intussusception rates in children in southern Israel during a 15-year period before the introduction of new rotavirus vaccines.

METHODS

All children born at the Soroka Medical Center are hospitalized in that center, enabling population-based studies. Two populations reside in Southern Israel: the Jewish population (comparable to a Western population) and the Bedouin population (comparable to a developing population). Retrospectively, all children <5 years of age admitted with ICD-9 code for intussusception were recorded as well as their demographic and clinical data.

RESULTS

During 1990-2004, 316 patients with intussusception [241 (76%) Jewish children and 75 (24%) Bedouin children] were recorded. None died. The mean annual rates for children <5 years (per 100,000) were 49.3 +/- 17.4 and 18.9 +/- 9.6 for Jewish and Bedouin children, respectively (P < 0.001), with a significant increase in intussusception rates during the study period in Bedouin (P = 0.022), but not in Jewish children (P = 0.38). Mean annual intussusception rates per 100,000 for children <12 months were 199.6 +/- 5.2 and 66.8 +/- 44.1 for Jews and Bedouin infants, respectively (P < 0.001). In Bedouin children, a significantly higher number of cases were observed from March to May, whereas no seasonality pattern was noted in Jewish children. Negative correlation between intussusception and gastroenteritis was found in Bedouin infants during the summer months, whereas no such correlation was found in Jewish infants.

CONCLUSIONS

Pre-rotavirus vaccination intussusception rate is high especially among Jewish infants in Southern Israel. Intussusception rates increased significantly during the study period in Bedouin infants.

Rapid detection and clinical features of infants and young children with acute lower respiratory tract infection due to respiratory syncytial virus

During December to the end of February of 2003 and 2004, a total of 282 nasopharyngeal aspirates were obtained from infants and young children admitted to the Buraidah Maternity and Pediatric Hospital, Al-Qassim, Saudi Arabia, and clinically diagnosed as suffering from acute lower respiratory tract infections. The aspirates were tested for the presence of respiratory syncytial virus using direct fluorescein-labeled monoclonal antibody assay. Of the 282 specimens, 128 (45.4%) were found to be positive for respiratory syncytial virus. The most positive specimens came from patients less than one year old (51.3%), and were associated with bronchopneumonia (56.7%) or bronchiolits (55.4%). Coughing (100%) and tachpnea (98%) were significantly more frequent in infants with respiratory syncytial virus infection, followed by wheezing, crepitation and retraction, each representing 66%. Three deaths were reported. The availability of a rapid viral diagnostic assay will be an important tool for physicians to make more accurate treatment decisions and therefore reduce unnecessary antibiotic usage and hospital stay for the patients.

Risk factors for hospitalization due to respiratory syncytial virus infection among infants in the Basque Country, Spain

This study analysed the role of several risk factors for hospitalization due to community-acquired, respiratory syncytial virus (RSV) infection. The risk factors detected in infants hospitalized for RSV infection in the first 24 months of life were compared with those in the general infant population in our region. There were 361 episodes of hospitalization in 357 infants. Eighty per cent of the infants did not present underlying conditions for severe RSV infection and only 10 (3%) were candidates for palivizumab prophylaxis. In multivariate analysis, birthweight of <2500 g was independently associated with hospitalization for RSV infection and was the most commonly detected medical risk factor. Other risk factors were maternal age at delivery <25 years, birth in the second half of the year, prematurity, suburban residence and congenital heart disease. In conclusion, together with well-known risk factors, we found that low birthweight was an independent factor for severe RSV infection.

Identification of an H-2D(b)-restricted CD8+ cytotoxic T lymphocyte epitope in the matrix protein of respiratory syncytial virus

Cytotoxic T lymphocytes (CTL) play a significant role in the clearance of respiratory syncytial virus (RSV) infection in humans and mice. Identification of class I MHC-restricted CTL epitopes is critical in elucidating mechanisms of CTL responses against viral infections. However, only four H-2d-restricted epitopes have been reported in mice. Because of the diversity of transgenic and knockout mice available to study immune responses, new epitopes in additional strains of mice must be identified. We therefore attempted to discover novel CTL epitopes in C57Bl/6 mice. Our efforts revealed a new H-2D(b)-restricted CTL epitope from the RSV M protein, corresponding to aa 187-195 (NAITNAKII). Also, M187-195-specific CTLs were activated with kinetics similar to the immunodominant BALB/c epitope, M2 82-90. This is the first RSV-specific CTL epitope described in a strain of mice other than BALB/c. Furthermore, identification of this H-2b-restricted CTL epitope provides access to genetically modified H-2b mice for more detailed studies of CTL mechanisms in RSV infection.

Community prescribing and resistant Streptococcus pneumoniae

We investigated the association between prescribing antimicrobial agents and antimicrobial resistance of Streptococcus pneumoniae among children with acute otitis media in southern Israel. During a 6-year period, all prescriptions of a sample of ≈20% of Jewish and Bedouin children <5 years of age were recorded and all pneumococcal isolates from middle ear fluid were collected. Although antimicrobial drug use was significantly higher in Bedouin children, the proportion of S. pneumoniae isolates with penicillin MIC ≥1.0 μg/mL was significantly higher in Jewish children. In both populations, antimicrobial prescriptions were markedly reduced over time, especially for penicillins and erythromycin. In contrast, azithromycin prescriptions increased from 1998 to 2001 with a parallel increase in macrolide and multidrug resistance. Penicillin resistance was associated with macrolide resistance. These findings strongly suggest that azithromycin affects increased antimicrobial resistance, including multidrug resistance, in S. pneumoniae.

Anemia as a risk factor for infectious diseases in infants and toddlers: results from a prospective study

Anemia due to iron deficiency is the most prevalent form of micronutrient malnutrition in the world, however, the causal relationship between anemia and infection remains unclear. We examined prospectively, the association between anemia and infection among Bedouin infants. We recruited 293 families and newborns from the Bedouin population, which is ongoing major lifestyle changes, during the periods of 1989-1992 and 1994-1997 and followed them to age 18 months. The number of diarrhea and respiratory disease episodes as well as total days of diarrhea were ascertained weekly. Hemoglobin levels were obtained at age 6 months. Additional data on feeding practices, environmental, household and demographic characteristics were obtained throughout the 18 months. Diarrhea before 6 months of age was found to be a risk factor for diarrhea after that age. After controlling for early morbidity < 6 months, anemia (Hb < 11 g/dl) at 6 months was an independent risk factor for diarrhea and respiratory illness from 7 to 18 months of age. This associations remained significant even after controlling, in addition, for environmental and socio-economic factors. In the multivariable models, anemia at age 6 months increased the risk for diarrhea after that age by 2.9-fold (95% confidence interval 1.6 - 5.3; p = 0.001) and that of respiratory disease by 2-fold (1.1 - 3.7; p = 0.03). Our findings suggest that anemia may increase the rates of infections in toddlers. The possibility that reducing anemia in infants may be a preventive measure to lower disease burden from infectious disease in this and other vulnerable populations should be tested in further studies.

Accuracy of acute otitis media diagnosis in community and hospital settings

AIM

To evaluate the accuracy rates of acute otitis media (AOM) diagnosis in the community by analyzing the initial AOM diagnosis (according to information from the referral letters to the Pediatric Emergency Department [PED]) among children with AOM diagnosis confirmed by tympanocentesis at PED.

METHODS

A descriptive, retrospective study conducted during the year 2000, including 590 children aged 0-48 mo diagnosed with AOM at PED. AOM was confirmed by tympanocentesis. We defined: (1) simple AOM as < 3 or < 4 episodes during the last 6 or 12 mo, respectively; (2) complicated AOM as > or = 3 or > or = 4 episodes during the last 6 or 12 mo, respectively, and/or not improving with antibiotics.

RESULTS

571 (96.8%) were < 24 mo of age; 355 (60%) were Arab Bedouins and 235 (40%) Jews. Seventy-three pediatricians, 57 general practitioners and 27 family practitioners provided referral letters. Information on disease severity was available in 471/590 (79.8%) patients, of whom 320 (68%) had simple and 151 (32%) complicated AOM. Three hundred and sixty-five (62%) of 590 patients were accurately diagnosed by referring physicians, more frequently in patients with complicated than simple AOM (p < 0.001). Diagnostic accuracy was similar among physician specialties (p = 0.33) and ethnic groups (p = 0.11). Multivariable logistic regression analysis showed that complicated AOM, adjusted for age, sex, ethnic origin, and physician specialty, was the only predictive factor for accurate AOM diagnosis (odds ratio 4.0, p < 0.001).

CONCLUSIONS

Inaccurate diagnosis of AOM in community settings is common, occurring more frequently in simple than in complicated AOM, and is unrelated to physician specialty and children's ethnicity.

Relative importance of nasopharyngeal versus oropharyngeal sampling for isolation of Streptococcus pneumoniae and Haemophilus influenzae from healthy and sick individuals varies with age

Streptococcus pneumoniae and Haemophilus influenzae carriage is a useful index for measuring the emergence of resistance and outcome in vaccination trials. We performed a study to determine which sampling site, nasopharynx (NP) or oropharynx (OP), yields the highest rate of S. pneumoniae and H. influenzae isolation at different ages. Both NP and OP cultures were obtained from 216 children aged <60 months and their mothers. The total S. pneumoniae carriage rate was 68% among children and 15% among mothers (P < 0.001). Using NP alone for the isolation of S. pneumoniae would have missed 2, 2, and 42% and using OP alone would have missed 77, 66, and 45% of S. pneumoniae in children aged 0 to 23 months, 24 to 59 months, and mothers, respectively. Using NP cultures alone for H. influenzae would have missed 23, 24, and 81% of the isolates, respectively. The respective figures for H. influenzae isolation from OP alone are 38, 29, and 9%. In children, S. pneumoniae was carried mainly in the NP while H. influenzae was equally carried in the NP and OP. In mothers, S. pneumoniae was carried equally in the NP and OP while H. influenzae was carried significantly more often in the OP. In children, H. influenzae colonization increased during illness, mainly in the NP. Culturing only one site significantly reduced the recovery of H. influenzae at all ages. NP cultures for S. pneumoniae detected close to 100% of isolates in children but only 58% of isolates in mothers.

Compliance with prophylaxis for respiratory syncytial virus infection in a home setting

BACKGROUND

Respiratory syncytial virus (RSV) is the most common respiratory pathogen in infancy and childhood.

OBJECTIVE

To compare the compliance and biologic efficacy of a home health care agency dosing-compliance program to treatment provided in a physician's office setting during a single RSV season (November to May). METHODS.: AAP guidelines were used to identify neonates who were eligible for RSV prophylaxis before discharge from a neonatal intensive care unit setting. Parents were asked to choose to receive the recommended treatment for their child either in their pediatrician's office setting or through a sequence of periodic nursing visits to their home. All home health care records were reviewed for demographics, number of doses received and hospitalization rate. Pediatricians office records were surveyed by telephone interview of their office staff and parents. Compliance data were calculated based on actual monthly injections given during the RSV season.

RESULTS

We followed prospectively 1446 infants who received palivizumab during a single RSV season (November 1, 2000 through April 30, 2001). Of these infants 67% (969 of 1446) received their monthly injections in the home setting where 98% of the doses were given on schedule. In contrast 477 infants (33%) received their injections in a pediatrician's office (parent's choice) with a compliance of only 89% for completion of all recommended doses (P < 0.001 vs. home setting). There were 9 RSV hospitalizations (0.93%) in the home setting group and 8 RSV hospitalizations (3.57%) in the office setting (P < 0.001). More parents indicated that the in-home prophylaxis program was more convenient than was true for those receiving treatment in the physician's office setting (P < 0.01).

CONCLUSIONS

Better compliance with home injections was associated with a decrease in the hospitalization rate for RSV with a higher degree of parental satisfaction.

Respiratory syncytial virus vaccine: Is it coming?

Respiratory syncytial virus (RSV) is recognized as an important cause of childhood morbidity and mortality. Vaccine development has been challenging in young infants and has required the advent of molecular technologies to optimize the safety profile, while maintaining immunogenicity of live-attenuated vaccines. Protein-based vaccines have been evaluated in clinical trials and are promising candidates for RSV-primed populations or for maternal vaccination to provide early life protection. This review provides a summary of the need for an RSV vaccine, as well as the challenges and progress in the vaccine's development.

Environmental and demographic risk factors for respiratory syncytial virus lower respiratory tract disease

OBJECTIVE

To critically review the literature examining risk factors for development of severe respiratory syncytial virus lower respiratory tract infection (RSV LRI).

STUDY DESIGN

A literature review was performed with the use of a MedLine search strategy. Clinical evidence of putative risk factors was rated by means of the US Preventive Services Task Force recommendations, and the quality of the data was critically assessed. Nonmedical risk factors examined included race/ethnicity, age of acquisition of RSV, sex, birth during the first half of the RSV season, breast-feeding, malnutrition, maternal education, socioeconomic status, crowding/siblings, day care, and tobacco smoke exposure.

RESULTS

There was sufficient evidence available to conclude that (1) male sex, (2) age <6 months, (3) birth during the first half of the RSV season, (4) crowding/siblings, and (5) day care exposure are significant risk factors for severe RSV LRI. There was insufficient evidence to evaluate the effect of race/ethnicity on severe RSV LRI. The evidence for tobacco smoke exposure is mixed. Low maternal education (as a proxy for lower socioeconomic status), lack of breast-feeding, and malnutrition did not appear to increase the risk of severe RSV LRI or RSV hospitalization.

CONCLUSIONS

Male sex, young age, birth in the first half of the RSV season, day care attendance, and crowding/siblings are independent risk factors for the development of severe RSV LRI.

Epidemiology of respiratory syncytial virus bronchiolitis in hospitalized infants in Greece

New therapies have been introduced for the prophylaxis and treatment of respiratory syncytial virus (RSV) infection in recent years. The aim of the study was to determine the epidemiological and clinical characteristics of infants hospitalized with bronchiolitis in our area. All patients under 1 year of age admitted with acute bronchiolitis during four consecutive RSV seasons from February 1, 1997 to June 30, 2000 were enrolled in the study. The records of patients admitted during the first season were reviewed retrospectively while the rest were followed prospectively. A total of 636 infants with bronchiolitis were admitted and RSV infection was documented in 61% of those tested. Admission to intensive care unit (ICU) was required for 6.2% of them and was more common in premature infants (26%) (p < 0.001). Case fatality rate was 0.7% (overall 0.3%). RSV bronchiolitis accounted for about 12% of all infant admissions during the 5 months of the yearly outbreak. Patients with documented RSV infection had a more severe illness with a higher ICU admission rate (6 vs. 1%, p = 0.008) and longer duration of hospitalization (mean 6.3 vs. 5.3 days, p < 0.001) compared to those who tested negative. Although none of the patients had a positive blood culture on admission a considerable number of them (210/636, 33%) were treated with antibiotics. RSV infection has a significant impact on infant morbidity in our settings which is more serious among those born prematurely. Documentation of RSV infection may be a marker of more severe illness in infants hospitalized with bronchiolitis. Antibiotic use has to be restricted since the occurrence of a serious bacteraemic illness on admission is a very rare event.

Impact of palivizumab prophylaxis on respiratory syncytial virus hospitalizations in high risk Alaska Native infants

BACKGROUND

Alaska Native children experience extremely high rates of hospitalization for respiratory syncytial virus (RSV) infection. We evaluated the effect of palivizumab prophylaxis on the incidence of RSV hospitalizations in high risk Alaska Native children.

METHODS

We analyzed two retrospective cohorts. The first analysis, of southwest Alaska Native children hospitalized with acute respiratory infections during 1993 to 1996 and 1998 to 2001, compared RSV hospitalization rates among premature and nonpremature infants born before (1993 to 1996) and after (1998 to 2001) palivizumab use. The second analysis, of Alaska Native infants with a history of prematurity or lung disease during 1998 through 2001, compared RSV hospitalization among children receiving palivizumab during protected periods (within 32 days after a dose of palivizumab) and unprotected periods.

RESULTS

First RSV hospitalizations in premature infants from southwest Alaska meeting criteria for palivizumab prophylaxis decreased from 439 per 1000 births before to 150 per 1000 births after palivizumab (relative rate, 0.34; 95% confidence interval, 0.17 to 0.68), whereas the rate in nonpremature infants remained stable (148 per 1000 births compared with 142 per 1000). Among high risk Alaska Native children during 1998 through 2001, the rate of first RSV hospitalization was 0.55 per 1000 protected days and 1.07 per 1000 unprotected days (relative rate, 0.52; 95% confidence interval, 0.28 to 0.93).

CONCLUSIONS

Palivizumab reduced RSV hospitalizations in high risk infants in a region with high rates of RSV hospitalization.

Respiratory syncytial virus epidemics: the ups and downs of a seasonal virus

Respiratory syncytial virus (RSV) is the most common pathogen causing lower respiratory tract infections in infants worldwide. Lower respiratory tract infections caused by RSV occur epidemically, and the appearance of epidemics seems to vary with latitude, altitude and climate. This study uses a review of the literature on RSV seasonality to investigate whether a global pattern in RSV epidemics can be found. A comparison of morbidity and mortality caused by RSV in developed vs. developing countries is also presented. The seasons in which RSV epidemics occur typically depend on geographic location and altitude. During these seasons the epidemics tend to appear in clusters. Although the appearance pattern of these epidemics varies from one continent to another, they usually begin in coastal areas. RSV is the cause of one-fifth of lower respiratory infections worldwide. Generally RSV mortality is low, with a median value of zero. However, RSV mortality in developing countries is significantly higher than RSV mortality in developed countries.

Respiratory syncytial virus prophylaxis: cost-effective analysis in Argentina

INTRODUCTION

Respiratory syncytial virus is a major cause of bronchiolitis during the first year of life. Preterm infants and patients with bronchopulmonary dysplasia (BPD) have a higher risk of hospitalization. The objective of this study was to assess the risk of hospitalization and to evaluate the cost effectiveness of palivizumab use in our at risk population.

METHODS

The study design was based on the hypothetical use of palivizumab in a cohort of patients. The cost effectiveness analysis included costs of palivizumab, the drug prescription and hospitalization. The effectiveness measure was the hospitalization rate decrease according to the result of the IMpact study: a 55% reduction in the need for hospitalization attributable to RSV. The years 1998 and 1999 were analyzed. Evaluable patients had follow-up at the High Risk Clinic and fulfilled the American Academy of Pediatrics criteria for palivizumab prophylaxis.

RESULTS

Forty-two patients, 24 with BPD and 18 preterm infants without BPD, were evaluated. Ten patients required hospitalization because of respiratory syncytial virus; one of them died. Hospitalization cost was $184,777. The total palivizumab administration cost would have been $185,064. With a 55% decrease of hospitalization rate, the cost per hospitalization averted would have been $15,358, and the number needed to treat would have been 7.9. A sensitivity analysis showed that the cost per hospitalization averted could range between $2,171 and $48,630 according to the hospitalization rate.

CONCLUSIONS

Because new effective but expensive treatments like palivizumab are available, this cost effective analysis can be an important tool in decisions about resource distribution.

Risk factors for severe respiratory syncytial virus infection among Alaska native children

OBJECTIVE

The incidence of hospitalization for respiratory syncytial virus (RSV) infection among Alaska Native children is much higher than among non-Native populations in the United States. We conducted this study to better understand factors associated with hospitalization attributable to RSV infection in this high-risk population.

DESIGN

Case-control study, including collection of cord blood for RSV-neutralizing antibody measurement.

SETTING

Remote region of southwest Alaska served by 1 regional hospital and 2 referral hospitals.

SUBJECTS

Case-patients identified through surveillance for RSV infection and matched control subjects without acute respiratory infection hospitalization.

RESULTS

Breastfeeding was associated with a lower risk of RSV hospitalization (odds ratio: 0.34), whereas underlying medical conditions (primarily prematurity) were associated with increased risk (odds ratio: 6.25). Environmental factors associated with a higher risk of hospitalization included household crowding (4 or more children in the household and crowding index > or =2). The level of maternal RSV-neutralizing antibody was not associated with the risk of hospitalization.

CONCLUSIONS

In this region with extremely high risk of RSV hospitalization, several measures, such as encouraging breastfeeding and reducing household crowding, could reduce the risk of hospitalization attributable to RSV.

A decade (1989-1998) of pediatric invasive pneumococcal disease in 2 populations residing in 1 geographic location: implications for vaccine choice

During 1 decade (1989-1998), data on invasive pneumococcal disease were collected prospectively to assess the burden of disease among Jewish and Bedouin children in southern Israel and the potential reduction in illness that can be achieved by using conjugate vaccines. Data on 513 children <15 years old with bacteriologically proven invasive pneumococcal disease were obtained. Among Jewish and Bedouin children <5 years old, incidence rates were 45 and 139 cases per 100,000 child-years of observation, respectively. Jewish and Bedouin children differed in clinical manifestations, seasonal patterns of disease, serotype distribution, and antibiotic susceptibility rates. The potential coverage by 7-, 9-, and 11-valent conjugate vaccines is 41%, 67%, and 71%, respectively, for Jewish children and 22%, 63%, and 65%, respectively, for Bedouin children. The 9- and 11-valent pneumococcal conjugate vaccines have the potential to substantially decrease invasive pneumococcal disease in southern Israel.

Enhanced detection of respiratory syncytial virus by shell vial in children hospitalised with respiratory illnesses in northern Jordan

During the period between November 1997 and May 1998, a total of 350 nasopharyngeal aspirates were obtained from children admitted to the Respiratory Disease Unit at Princess Rahma Hospital, northern Jordan, and diagnosed clinically as suffering from respiratory tract infections. Nasopharyngeal aspirates were investigated for the presence of respiratory syncycial virus (RSV) by using shell vial (SV) culture assay, conventional culture assay, and direct immunofluorescence assay. Out of 350 nasopharyngeal aspirates, 101(28.9%) were found positive by any of SV, conventional culture, and immunofluorescence; 91 (90.1%) by SV, 87(86.1%) by culture, and 83(82.2%) by immunofluorescence. The maximum number of virus isolations was noted in children below the age of 1 year and was associated with bronchiolitis. SV assay showed the highest sensitivity (94.3%) and specificity (96.9%) for detecting RSV from nasopharyngeal aspirates. These results emphasise the importance of SV culture assay for diagnosis of RSV, although immunofluorescence is a valuable, rapid diagnostic assay.

Bronchiolitis-associated hospitalizations among American Indian and Alaska Native children

BACKGROUND

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract illness among infants and young children. Respiratory system diseases account for a large proportion of hospitalizations in American Indian and Alaska Native (AI/AN) children; however, aggregate estimates of RSV-associated hospitalizations among AI/AN children have not been made.

METHODS

We used Indian Health Service hospitalization data from 1990 through 1995 to describe hospitalizations associated with bronchiolitis, the most characteristic clinical manifestation of RSV infection, among AI/AN children <5 years old.

RESULTS

The overall bronchiolitis-associated hospitalization rate among AI/AN infants < 1 year old was considerably higher (61.8 per 1,000) than the 1995 estimated bronchiolitis hospitalization rate among all US infants (34.2 per 1,000). Hospitalization rates were higher among male infants (72.2 per 1,000) than among females infants (51.1 per 1,000). The highest infant hospitalization rate was noted in the Navajo Area (96.3 per 1,000). Hospitalizations peaked annually in January or February, consistent with national peaks for RSV detection. Bronchiolitis hospitalizations accounted for an increasing proportion of hospitalizations for lower respiratory tract illnesses.

CONCLUSIONS

Bronchiolitis-associated hospitalization rates are substantially greater for AI/AN infants than those for all US infants. This difference may reflect an increased likelihood of severe RSV-associated disease or a decreased threshold for hospitalization among AI/AN infants with bronchiolitis compared with all US infants. AI/AN children would receive considerable benefit from lower respiratory tract illness prevention programs, including an RSV vaccine, if and when one becomes available.

Maternal immunization against viral disease

The protective effect of maternal antibody against many viral diseases has been recognized. The use of maternal immunization has been considered as a means to augment this protection in the young infant against disease. Advantages of maternal immunization include the fact that young infants are most susceptible to infections but least responsive to vaccines, that pregnant women are accessible to medical care and respond well to vaccines, that IgG antibodies cross the placenta well during the third trimester, and that immunization of the pregnant woman has the potential to benefit both the mother and the infant. Disadvantages include the potential inhibition of an infant's response to active immunization or natural infection and liability issues with pharmaceutical companies and physicians. Immunization of pregnant women with viral vaccines for poliovirus, influenza viruses, and rubella has been described and maternal vaccination with these vaccines has been found to be safe for both the mother and the fetus. An open-label study of post-partum women immunized with the purified fusion protein of RSV (PFP-2, Wyeth-Lederle Pediatrics and Vaccines, Inc., Pearl River, NY) demonstrated that the vaccine was non-reactogenic and immunogenic; RSV-specific antibody was detected in breast milk. Immunization of pregnant women with purified protein or subunit vaccines could be considered against neonatal viral pathogens, such as respiratory syncytial virus, parainfluenza viruses, herpes group viruses, and human immunodeficiency virus. Further studies are needed to define the safety and efficacy of maternal immunization.

Respiratory syncytial virus infection in tropical and developing countries

Little is known about the epidemiology of respiratory syncytial virus (RSV) infection in tropical and developing countries; the data currently available have been reviewed. In most studies, RSV was found to be the predominant viral cause of acute lower respiratory tract infections (ALRI) in childhood, being responsible for 27-96% of hospitalised cases (mean 65%) in which a virus was found. RSV infection is seasonal in most countries; outbreaks occur most frequently in the cold season in areas with temperate and Mediterranean climates and in the wet season in tropical countries with seasonal rainfall. The situation on islands and in areas of the inner tropics with perennial high rainfall is less clear-cut. The age group mainly affected by RSV in developing countries is children under 6 months of age (mean 39% of hospital patients with RSV). RSV-ALRI is slightly more common in boys than in girls. Very little information is available about the mortality of children infected with RSV, the frequency of bacterial co-infection, or the incidence of further wheezing after RSV. Further studies on RSV should address these questions in more detail. RSV is an important pathogen ill young children in tropical and developing countries and a frequent cause of hospital admission. Prevention of RSV infection by vaccination would have a significant impact on the incidence of ALRI in children in developing countries.

The clinical spectrum of respiratory syncytial virus disease in The Gambia

BACKGROUND

Respiratory syncytial virus (RSV) is a well-recognized cause of lower respiratory tract infections in early childhood in industrialized countries, but less is known about RSV infection in developing countries.

METHODS

Four outbreaks of RSV infection that occurred between 1993 and 1996 in The Gambia, West Africa, were studied. RSV was sought by immunofluorescent staining of nasopharyngeal aspirate samples among young children who presented with respiratory infections at three hospitals in the Western Region of the country.

RESULTS

Five hundred seventy-four children with RSV infection were identified. The median ages of children seen in 1993 through 1996 were 3, 7, 8 and 5 months, respectively. Sixty-two percent of children <6 months old were boys. Thirteen children (2.4%) had conditions considered to increase the risk of severe RSV infection. On physical examination crepitations were heard in 80% of the children admitted to hospital, whereas wheezes were heard in only 39%. Eighty (16%) children received oxygen because of hypoxemia. Nine of 255 blood cultures (3.5%) were positive: 4 Streptococcus pneumoniae; 2 Haemophilus influenzae type b; 2 Staphylococcus aureus; and 1 Enterobacter agglomerans. Thirteen children died (2.4%). During the 4 study years 90, 25, 75 and 95% of isolates typed were RSV Subgroup A, respectively.

CONCLUSIONS

RSV is a significant cause of lower respiratory tract infection in young children in The Gambia, causing epidemics of bronchiolitis. It poses a significant burden on the health system, especially through the demand for supplementary oxygen. The clinical spectrum of RSV disease in The Gambia is similar to that seen in developed countries; concomitant bacterial infections are uncommon.

Hospitalizations for infectious diseases in Jewish and Bedouin children in southern Israel

Two different population groups reside in the Negev region of southern Israel and have equal, and free from financial barrier, access to tertiary care at a single regional hospital. The Jewish population has a largely urban and industrialized lifestyle, while the Moslem Bedouins are in transition from their traditional nomadic life to settlement. To examine the differences in morbidity patterns reflected in hospitalizations, the computerized hospitalization records of children <15 years of age, for 1989-1991 were used (n=15,947). Rates of hospitalizations for infectious diseases were significantly higher for Bedouins in comparison to Jews (250 and 121/10,000 child years, respectively, odds ratio (OR): 2.1, 95% confidence interval (CI): 2.0-2.2, p < 0.001). Rates of hospitalization per 10,000 child years in Bedouins and Jews for diarrhea were 114 and 32 (OR: 3.7, 95% CI: 3.3-4.0, p < 0.001), respectively, and for pneumonia 55 and 19 (OR: 2.9, 95% CI: 2.6-3.3, p < 0.001), respectively. In infants the differences were even more pronounced, especially for diarrheal diseases. In Bedouin children infectious diseases were associated with longer hospital stay, more pediatric Intensive Care hospitalizations (OR: 2.7, 95% CI: 1.7-4.5,p < 0.001), and higher in-hospital mortality (OR: 5.7, 95% CI: 2.8-12.2, p < 0.001). Thus, Bedouin children are at higher risks of hospitalizations for infectious diseases in early childhood, as compared to Jewish children. This may reflect the differences in lifestyle, environmental and social conditions of the two populations.

A prospective study of neonatal sepsis and meningitis in southern Israel

OBJECTIVE

To study the epidemiology of neonatal sepsis and meningitis in the Negev area of southern Israel.

DESIGN

A prospective 8-year study conducted at the neonatal intensive care unit and pediatric wards of the Soroka University Medical Center.

RESULTS

Two hundred twenty-nine cases of hospital and community-acquired neonatal sepsis occurred during the study period. Thirty-two patients (14%) were meningitis. During this period 70,709 births (59% Jews and 41% Bedouins) were recorded; thus the rates of neonatal sepsis and meningitis were 3.2 and 0.5/1000 live births, respectively. One hundred seventeen (4/1000 live births) cases were recorded in Bedouins and 112 (2.6/1000 live births) in Jewish neonates (P < 0.001). Twenty-six percent of all sepsis cases occurred within < 24 h from birth, 25% from Days 2 to 7 of life and 49% between Days 8 and 28. A total of 251 organisms that were considered true pathogens were isolated. Fifty-seven of all isolates were Gram-negative organisms (mainly Klebsiella pneumoniae (20%) and Escherichia coli (16%)). Gram-positive organisms were isolated in 41% of cases. Although E. coli was the most frequently recovered Gram-negative pathogen in community-acquired late onset sepsis, Klebsiella and Enterobacter spp. represented the most commonly isolated Gram-negative organisms in nosocomial late onset sepsis. All Staphylococcus aureus isolates recovered in late onset sepsis were nosocomial. The incidence of Streptococcus agalactiae was 3 times higher in early onset sepsis than in late onset sepsis. All cases of Streptococcus pneumoniae sepsis occurred in Bedouins.

CONCLUSIONS

Neonatal sepsis and meningitis rates in southern Israel are similar to those reported in Western Europe and the United States. The incidence of neonatal sepsis is significantly higher for Bedouins than for Jewish neonates. The distribution of the main pathogens is different in southern Israel and although Gram-negative enteric organisms are predominant, S. agalactiae plays a relatively minor role in the etiology of sepsis during the first month of life. In southern Israel the etiology of community-acquired late onset sepsis is different from that of nosocomial late onset sepsis.

Oral versus nebulized albuterol in the management of bronchiolitis in Egypt

The efficacy of albuterol in the management of infants with first-time wheezing is controversial. This double-blind, placebo-controlled trial involved 128 Egyptian infants with first-time wheezing (mean age 5.9 months) who were randomly separated into four equivalent therapy groups: nebulized albuterol, nebulized saline solution, orally administered albuterol, and orally administered placebo. The nebulized therapy groups received two treatments 30 minutes apart; the oral therapy groups received one treatment. In addition, 41 infants with recurrent wheezing comprised an open-label control group who received two albuterol nebulizations. Chest radiographs, leukocyte counts, blood culture specimens, and nasal aspirate for viral antigen detection were obtained to confirm the clinical diagnosis of viral bronchiolitis. Respiratory and heart rates, clinical score, and oxygen saturation were recorded at baseline and 30 and 60 minutes after treatment. There was no difference among the four randomized groups in any of the outcomes except for an increase in heart rate of 10 beats/min in the nebulized albuterol group compared with a decrease in heart rate of 8 beats/min in the oral placebo group. No differences in the need for additional treatment were observed. Nebulized albuterol significantly improved the clinical score and reduced the respiratory rate of those with recurrent wheezing relative to those in the randomized groups. We conclude that nebulized albuterol is effective in the treatment of infants with recurrent wheezing, but there was no demonstrable efficacy of orally administered or nebulized albuterol in relieving the respiratory distress of infants with bronchiolitis in Egypt.