Influencia del hábito tabáquico familiar en la hospitalización infantil por enfermedades respiratorias en los dos primeros años de vida

Risk factors for severe bronchiolitis caused by respiratory virus infections among Mexican children in an emergency department

Severe bronchiolitis is the most common reason for hospitalization among children younger than 2 years. This study analyzed the prevalence of community-acquired respiratory virus infection and the risk factors for hospitalization of Mexican children with severe bronchiolitis treated in an Emergency department.This retrospective study included 134 children 2 years or younger with severe viral bronchiolitis, and 134 healthy age-matched controls. The study period was September 2012 to January 2015. We determined the viral etiology and coinfections with multiple viruses and compared the risk factors detected in children with severe viral bronchiolitis with those in the control group.A total of 153 respiratory viruses in these 134 patients, single or mixed infections, were identified: respiratory syncytial virus (RSV) type A or B was the most frequently detected (23.6% and 17.6%, respectively), followed by rhinovirus (RV; 16.3%) and parainfluenza virus (PIV) type 3 (12.4%). Coinfections of 2 respiratory viruses were found in 14.2% of cases; all cases had either RSV type A or B with another virus, the most common being parainfluenza virus or rhinovirus. Exposure to cigarette smoking was independently associated with hospitalization for severe bronchiolitis (OR, 3.5; 95% CI, 1.99-6.18; P = .0001), and having completed the vaccination schedule for their age was a protective factor against adverse outcome (OR, 0.55; 95% CI, 0.35-0.87; P = .010).RSV is a common infection among young children with severe bronchiolitis; thus, developing a vaccine against RSV is essential. Campaigns to reinforce the importance of avoiding childhood exposure to cigarette smoke are also needed.

[Consensus conference on acute bronchiolitis (II): epidemiology of acute bronchiolitis. Review of the scientific evidence]

A review of the evidence on epidemiology, risk factors, etiology and clinical-etiological profile of acute bronchiolitis is presented. The frequency estimates are very heterogeneous; in the population under two years the frequency of admission for bronchiolitis is between 1 and 3.5%, primary care consultations between 4 and 20% and emergency visits between 1 and 2%. The frequency of admissions for respiratory infection by respiratory syncytial virus in the risk population is: in premature infants < or =32 weeks of gestation between 4.4 and 18%, in patients with bronchopulmonary dysplasia between 7.3 and 42%, and in infants with congenital heart disease between 1.6 and 9.8%. The main risk factors are: prematurity, chronic lung disease or bronchopulmonary dysplasia, congenital heart disease and age less than 3-6 months at onset of the epidemic. Other factors are: older siblings or day care attendance, male gender, exposure to smoking, breastfeeding for less than 1-2 months and variables associated with lower socioeconomic status. Respiratory syncytial virus is the dominant etiological agent, constituting just over half the cases (median 56%; interval 27% to 73%). Other viruses implicated, in descending order of frequency, are rhinovirus, adenovirus, metapneumovirus, influenza viruses, parainfluenza, enterovirus and bocavirus. In studies with genomic detection techniques, between 20 and 25% of cases the virus involved is not identified and between 9% and 27% of cases have viral co-infection. Although respiratory syncytial virus bronchiolitis shows more wheezing and retractions, longer duration of respiratory symptoms and oxygen therapy and are associated with lower use of antibiotics. This pattern is associated with the younger age of the patients and does not help us to predict the etiology. In general, the etiological identification is not useful for the management of patients. However, in young infants (<3 months) with febrile bronchiolitis in the hospital environment, conservative management may help these patients and avoid diagnostic and therapeutic procedures.

Full breastfeeding and hospitalization as a result of infections in the first year of life

OBJECTIVE

Our objective was to assess the effect of breastfeeding on the probability of hospitalization as a result of infectious processes during the first year of life

METHODS

We followed 1385 infants from birth to age 1 year between 1996 and 1999. Recruitment and data collection were done at the 6-month well-infant visit under the National Child Health Program. Full breastfeeding, hospital admission, and other relevant variables related to the delivery, infant, mother, health services system, and sociologic aspects were recorded. The statistical analysis included Kaplan-Meier test, Cox regression to obtain the hazard ratio, and the adjusted attributable risk.

RESULTS

Full breastfeeding at discharge after delivery and at 3, 4, and 6 months of age were 85%, 52%, 41%, and 15%, respectively; 78 hospital admissions as a result of infections were recorded (38 respiratory tract, 16 gastrointestinal tract). Mean age at admission was 4.1 months. After estimating the attributable risk, it was found that 30% of hospital admissions would have been avoided for each additional month of full breastfeeding. Seemingly, 100% of full breastfeeding among 4-month-old infants would avoid 56% of hospital admissions in infants who are younger than 1 year.

CONCLUSIONS

On the basis of the present data, we conclude that full breastfeeding would lower the risk for hospital admission as a result of infections among infants who are younger than 1 year within an industrialized country.

[Pre and postnatal tobacco exposure and bronchiolitis]

OBJECTIVES

To determine the influence of pre- and postnatal tobacco exposure in the development of bronchiolitis.

PATIENTS AND METHODS

A questionnaire was given to the parents of children hospitalized between August 2001 and August 2002. It included items on parental smoking habits and maternal smoking during pregnancy. Clinical, analytical and radiological criteria were used to diagnose bronchiolitis.

RESULTS

Of 450 children, 123 (27.3 %) were diagnosed with bronchiolitis. The control group was composed of 327 children. A total of 61.6 % of the children had at least one parent who smoked and 32.9 % of these children developed bronchiolitis; 39.1 % had non-smoking parents and 18.2 % were hospitalized with bronchiolitis (OR 2.20 [1.39-3.47]). Of the entire group of children studied, 35.3 % had mothers who smoked and 37.7 % of these children had bronchiolitis compared with 21.4 % of children whose mothers were non-smokers (OR 2.22 [1.45-3.39]). A total of 49.6 % had fathers who smoked, and 32.3 % of these children were diagnosed with bronchiolitis compared with 22 % of children whose fathers were non-smokers (OR 1.65 [1.10-2.57]). Forty-four percent of children whose mothers smoked during pregnancy were hospitalized with bronchiolitis compared with only 20.9 % of non-exposed children (OR 2.96 [1.90-4.62]). The large number of mothers who smoked during pregnancy (27.8 %) was notable. Multivariant analysis with logistic regression was performed and the only variable that remained statistically significant was smoking during pregnancy (p < 0.00001; OR 3.27 [1.39-7.71]).

CONCLUSIONS

Maternal smoking during pregnancy seems to be the main risk factor for the subsequent development of bronchiolitis

Tabaco, lactancia y sibilantes en los primeros tres años

BACKGROUND

Wheezing lower respiratory tract diseases are frequent and troublesome in young children. However, the only avoidable risk factors for them are tobacco smoke exposure and feeding practices.

OBJECTIVE

To measure the influence of these avoidable factors on the risk of wheeze in the first 3 years of life.

METHODS

We performed a population study including all the children born between January 1998 and November 2002 who were attended in the same primary health center in Palencia (Spain) from birth. Information on family history, pregnancy, delivery, and smoking was obtained soon after birth. Feeding practices were recorded on monthly visits. Wheezing episodes in the first 3 years of life were identified by a pediatrician.

RESULTS

Two hundred thirty-four children were included and 43 had at least one episode of wheezing. The results were adjusted by sex, prematurity, a family history of allergy, having older siblings, maternal age, and month of birth. No association was found between wheezing and exclusive breast feeding for 3 months (hazard ratio [HR] 5 0.83, 95 % CI: 0.42-1.64), or with postnatal exposure to tobacco smoke (HR 5 1.2, 95 % CI: 0.45-2.34). Tobacco smoke exposure during pregnancy was associated with a higher risk of wheezing: HR 5 2.54 (95 % CI: 1.18-5.48).

CONCLUSIONS

Prenatal exposure to tobacco smoke is the main modifiable risk factor for wheezing diseases in the first 3 years of life.