Abstracts
OBJECTIVE:
To determine, in a sample of infants, the prevalence of and risk factors for occasional wheezing (OW) and recurrent wheezing-wheezy baby syndrome (WBS).
METHODS:
Parents of infants (12-15 months of age) completed the International Study of Wheezing in Infants questionnaire.
RESULTS:
We included 1,269 infants residing in the city of Blumenau, Brazil. Of those, 715 (56.34%) had a history of wheezing, which was more common among boys. The prevalences of OW and WBS were 27.03% (n = 343) and 29.31% (n = 372), respectively. On average, the first wheezing episode occurred at 5.55 ± 2.87 months of age. Among the 715 infants with a history of wheezing, the first episode occurred within the first six months of life in 479 (66.99%), and 372 (52.03%) had had three or more episodes. Factors associated with wheezing in general were pneumonia; oral corticosteroid use; a cold; attending daycare; having a parent with asthma or allergies; mother working outside the home; male gender; no breastfeeding; and mold. Factors associated with WBS were a cold; physician-diagnosed asthma; ER visits; corticosteroid use; pneumonia; bronchitis; dyspnea; attending daycare; bronchodilator use; having a parent with asthma; no breastfeeding; mother working outside the home; and a dog in the household.
CONCLUSIONS:
The prevalence of wheezing in the studied population was high (56.34%). The etiology was multifactorial, and the risk factors were intrinsic and extrinsic (respiratory tract infections, allergies, attending daycare, and early wheezing). The high prevalence and the intrinsic risk factors indicate the need and the opportunity for epidemiological and genetic studies in this population. In addition, mothers should be encouraged to prolong breastfeeding and to keep infants under six months of age out of daycare.
Asthma; Prevalence; Risk factors
OBJETIVO:
Determinar a prevalência e os fatores de risco para sibilância ocasional (SO) e recorrente - síndrome do lactente sibilante (SLS).
MÉTODOS:
Pais de lactentes (12-15 meses de idade) responderam o questionário escrito Estudio Internacional de Sibilancias en Lactantes.
RESULTADOS:
Foram incluídos 1.269 lactentes residentes na cidade de Blumenau (SC). Desses, 715 (56,34%) apresentavam sibilância, sendo essa mais frequente nos meninos. As prevalências de SO e SLS foram de 27,03% (n = 343) e 29,31% (n = 372), respectivamente. O primeiro episódio de sibilância ocorreu aos 5,55 ± 2,87 meses de idade em média. Em 479/715 (66,99%) lactentes com sibilância, o primeiro episódio ocorreu nos primeiros seis meses de vida, enquanto 372/715 (52,03%) apresentaram três ou mais episódios. Os fatores associados com sibilância foram pneumonia; uso de corticoide oral; resfriado; frequência a creches; pais com asma e/ou alergia; mãe com emprego; gênero masculino; sem aleitamento materno; e mofo. Os fatores associados com SLS foram resfriado; diagnóstico médico de asma; visitas a serviço de emergência; uso de corticoide oral/inalatório; pneumonia, bronquite; dispneia; frequência a creches; uso de broncodilatador; pais com asma; sem aleitamento materno; mãe com emprego; e presença de cachorro na residência.
CONCLUSÕES:
A prevalência de sibilância na população estudada foi elevada, sendo multifatorial e com fatores de risco intrínsecos e extrínsecos (infecções do trato respiratório, alergia nos pais, frequência a creches e idade precoce de chiado). A elevada prevalência e os fatores de risco intrínsecos encontrados indicam a necessidade e a oportunidade para estudos epidemiológicos e genéticos nessa população. Além disso, estratégias para que as mães aumentem o período de amamentação ao seio e evitem que seus filhos frequentem creches antes dos seis primeiros meses de vida devem ser estimuladas.
Asma; Prevalência; Fatores de risco
Introduction
Wheezing in the first year of life can be classified as occasional wheezing (OW) or
recurrent wheezing, the latter being known as wheezy baby syndrome (WBS). Both are
common clinical conditions that are heterogeneous and are caused by numerous diseases
and airway injury, manifesting clinically and biochemically as a variety of
phenotypes.(
11. Martinez FD, Wright AL, Taussig LM, Holberg CJ, Halonen M, Morgan WJ.
Asthma and wheezing in the first six years of life. The Group Health Medical
Associates. N Engl J Med.
1995;332(3):133-8.http://dx.doi.org/10.1056/NEJM199501193320301
http://dx.doi.org/10.1056/NEJM1995011933...
,
22. Chong Neto HJ, Rosário NA, Solé D, Mallol J. Prevalence of recurrent
wheezing in infants. J Pediat (Rio J).
2007;83(4):357-62.http://dx.doi.org/10.1590/S0021-75572007000500012
http://dx.doi.org/10.1590/S0021-75572007...
)
Some children have transient early WBS, whereas others have early respiratory symptoms
that can be the first manifestation of asthma. In recent decades, studies have
investigated the risk factors for WBS and the relationship between WBS and the
development of asthma, issues that are central to asthma prevention.(
11. Martinez FD, Wright AL, Taussig LM, Holberg CJ, Halonen M, Morgan WJ.
Asthma and wheezing in the first six years of life. The Group Health Medical
Associates. N Engl J Med.
1995;332(3):133-8.http://dx.doi.org/10.1056/NEJM199501193320301
http://dx.doi.org/10.1056/NEJM1995011933...
) Most school-age children with a history of asthma and impaired pulmonary
function have a history of OW or WBS in the first year of life.
Studies conducted in Brazil(
22. Chong Neto HJ, Rosário NA, Solé D, Mallol J. Prevalence of recurrent
wheezing in infants. J Pediat (Rio J).
2007;83(4):357-62.http://dx.doi.org/10.1590/S0021-75572007000500012
http://dx.doi.org/10.1590/S0021-75572007...
3. Chong Neto HJ, Rosário NA; Grupo EISL Curitiba (Estudio Internacional
de Sibilancias en Lactantes). Risk factors for wheezing in the first year of life. J
Pediatr (Rio J). 2008;84(6):495-502.
http://dx.doi.org/10.1590/S0021-75572008000700005
http://dx.doi.org/10.1590/S0021-75572008...
4. Dela Bianca AC, Wandalsen GF, Mallol J, Solé D. Prevalence and
severity of wheezing in the first year of life. J Bras Pneumol.
2010;36(4):402-9.http://dx.doi.org/10.1590/S1806-37132010000400003
http://dx.doi.org/10.1590/S1806-37132010...
5. Dela Bianca A, Wandalsen G, Mallol J, Sole D. Risk factors for
wheezing disorders in infants in the first year of life living in São Paulo, Brazil.
J Trop Pediatr. 2012;58(6):501-4. http://dx.doi.org/10.1093/tropej/fms016
http://dx.doi.org/10.1093/tropej/fms016...
6. Moraes LS, Takanoa AO, Mallol J, Solé D. Risk factors associated with
wheezing in infants. J Pediatr (Rio J).
2013;89(6):559-66.http://dx.doi.org/10.1016/j.jped.2013.04.004
http://dx.doi.org/10.1016/j.jped.2013.04...
7. Medeiros D, Silva AR, Rizzo JA, Sarinho E, Mallol J, Sole D.
Prevalence of wheezing and associated risk factors among infants in Recife,
Pernambuco State, Brazil [Article in Portuguese]. Cad Saude Publica.
2011;27(8):1551-9. http://dx.doi.org/10.1590/S0102-311X2011000800010
http://dx.doi.org/10.1590/S0102-311X2011...
-
88. Rosa AM, Jacobson Lda S, Botelho C, Ignotti E. Prevalence of wheezing
and associated factors in children under 5 years of age in Cuiabá, Mato Grosso State,
Brazil [Article in Portuguese]. Cad Saude Publica. 2013;29(9):1816-28.
http://dx.doi.org/10.1590/S0102-311X2013001300021
http://dx.doi.org/10.1590/S0102-311X2013...
) and other countries(
99. Mallol J, Andrade R, Auger F, Rodriguez J, Alvarado R, Figueroa L.
Wheezing during the first year of life in infants from low-income population: a
descriptive study. Allergol Immunopathol (Madr).
2005;33(5):257-63.http://dx.doi.org/10.1157/13080928
http://dx.doi.org/10.1157/13080928...
10. Mallol J, García-Marcos L, Solé D, Brand P; the EISL Study Group.
International prevalence of recurrent wheezing during the first year of life:
variability, treatment patterns and use of health resources. Thorax.
2010;65(11):1004-9.http://dx.doi.org/10.1136/thx.2009.115188
http://dx.doi.org/10.1136/thx.2009.11518...
11. Visser CA, Garcia-Marcos L, Eggink J, Brand PL. Prevalence and risk
factors of wheeze in Dutch infants in their first year of life. Pediatr Pulmonol.
2010; 45(2):149-56. http://dx.doi.org/10.1002/ppul.21161
http://dx.doi.org/10.1002/ppul.21161 ...
-
1212. Venero-Fernándes SL, Suárez-Medina R, Mora-Faife EC, García-García
G, Valle-Infante I, Gómez-Marrero L, et al. Risk factors for wheezing in infants born
in Cuba. QJM. 2013;106(11):1023-9. http://dx.doi.org/10.1093/qjmed/hct143
http://dx.doi.org/10.1093/qjmed/hct143...
) have shown that OW and WBS are common in the first year of life, their
prevalence ranging from 13.0% to 80.3%. Although the prevalence of WBS is high, it has
been reported that WBS disappears after early childhood.(
11. Martinez FD, Wright AL, Taussig LM, Holberg CJ, Halonen M, Morgan WJ.
Asthma and wheezing in the first six years of life. The Group Health Medical
Associates. N Engl J Med.
1995;332(3):133-8.http://dx.doi.org/10.1056/NEJM199501193320301
http://dx.doi.org/10.1056/NEJM1995011933...
) Because the prevalence of wheezing is high, it is necessary to determine
the severity of and risk factors for OW and WBS in the first year of life in Brazil.
OW and WBS in the first year of life are noteworthy for two reasons: (i) individuals
exposed to risk factors for OW or WBS are more likely to develop asthma; (ii) most
patients with WBS have viral exacerbations, without atopy, and do not develop
asthma.(
22. Chong Neto HJ, Rosário NA, Solé D, Mallol J. Prevalence of recurrent
wheezing in infants. J Pediat (Rio J).
2007;83(4):357-62.http://dx.doi.org/10.1590/S0021-75572007000500012
http://dx.doi.org/10.1590/S0021-75572007...
,
1313. Guilbert TW, Morgan WJ, Zeiger RS, Bacharier LB, Boehmer SJ, Krawiec
M, et al. Atopic characteristics of children with recurrent wheezing at high risk for
the development of childhood asthma. J Allergy Clin Immunol.
2004;114(6):1282-7.http://dx.doi.org/10.1016/j.jaci.2004.09.020
http://dx.doi.org/10.1016/j.jaci.2004.09...
)
Prevalence studies of OW and WBS in the first year of life have identified several risk
factors, including a family history of asthma; certain dietary and occupational habits
during pregnancy; passive smoking; lack of breastfeeding; male gender; attending
daycare; certain environmental pollutants (cigarette smoke and sensitization to
aeroallergens, including dust mite aeroallergens, cockroach aeroallergens, and animal
dander); pneumonia or viral respiratory infections caused by respiratory syncytial virus
or rhinovirus; and use of antibiotics or paracetamol.(
22. Chong Neto HJ, Rosário NA, Solé D, Mallol J. Prevalence of recurrent
wheezing in infants. J Pediat (Rio J).
2007;83(4):357-62.http://dx.doi.org/10.1590/S0021-75572007000500012
http://dx.doi.org/10.1590/S0021-75572007...
3. Chong Neto HJ, Rosário NA; Grupo EISL Curitiba (Estudio Internacional
de Sibilancias en Lactantes). Risk factors for wheezing in the first year of life. J
Pediatr (Rio J). 2008;84(6):495-502.
http://dx.doi.org/10.1590/S0021-75572008000700005
http://dx.doi.org/10.1590/S0021-75572008...
4. Dela Bianca AC, Wandalsen GF, Mallol J, Solé D. Prevalence and
severity of wheezing in the first year of life. J Bras Pneumol.
2010;36(4):402-9.http://dx.doi.org/10.1590/S1806-37132010000400003
http://dx.doi.org/10.1590/S1806-37132010...
5. Dela Bianca A, Wandalsen G, Mallol J, Sole D. Risk factors for
wheezing disorders in infants in the first year of life living in São Paulo, Brazil.
J Trop Pediatr. 2012;58(6):501-4. http://dx.doi.org/10.1093/tropej/fms016
http://dx.doi.org/10.1093/tropej/fms016...
6. Moraes LS, Takanoa AO, Mallol J, Solé D. Risk factors associated with
wheezing in infants. J Pediatr (Rio J).
2013;89(6):559-66.http://dx.doi.org/10.1016/j.jped.2013.04.004
http://dx.doi.org/10.1016/j.jped.2013.04...
7. Medeiros D, Silva AR, Rizzo JA, Sarinho E, Mallol J, Sole D.
Prevalence of wheezing and associated risk factors among infants in Recife,
Pernambuco State, Brazil [Article in Portuguese]. Cad Saude Publica.
2011;27(8):1551-9. http://dx.doi.org/10.1590/S0102-311X2011000800010
http://dx.doi.org/10.1590/S0102-311X2011...
8. Rosa AM, Jacobson Lda S, Botelho C, Ignotti E. Prevalence of wheezing
and associated factors in children under 5 years of age in Cuiabá, Mato Grosso State,
Brazil [Article in Portuguese]. Cad Saude Publica. 2013;29(9):1816-28.
http://dx.doi.org/10.1590/S0102-311X2013001300021
http://dx.doi.org/10.1590/S0102-311X2013...
9. Mallol J, Andrade R, Auger F, Rodriguez J, Alvarado R, Figueroa L.
Wheezing during the first year of life in infants from low-income population: a
descriptive study. Allergol Immunopathol (Madr).
2005;33(5):257-63.http://dx.doi.org/10.1157/13080928
http://dx.doi.org/10.1157/13080928...
10. Mallol J, García-Marcos L, Solé D, Brand P; the EISL Study Group.
International prevalence of recurrent wheezing during the first year of life:
variability, treatment patterns and use of health resources. Thorax.
2010;65(11):1004-9.http://dx.doi.org/10.1136/thx.2009.115188
http://dx.doi.org/10.1136/thx.2009.11518...
11. Visser CA, Garcia-Marcos L, Eggink J, Brand PL. Prevalence and risk
factors of wheeze in Dutch infants in their first year of life. Pediatr Pulmonol.
2010; 45(2):149-56. http://dx.doi.org/10.1002/ppul.21161
http://dx.doi.org/10.1002/ppul.21161 ...
-
1212. Venero-Fernándes SL, Suárez-Medina R, Mora-Faife EC, García-García
G, Valle-Infante I, Gómez-Marrero L, et al. Risk factors for wheezing in infants born
in Cuba. QJM. 2013;106(11):1023-9. http://dx.doi.org/10.1093/qjmed/hct143
http://dx.doi.org/10.1093/qjmed/hct143...
)
The Estudio Internacional de Sibilancias en Lactantes (EISL,
International Study of Wheezing in Infants) questionnaire was created in 2005 in order
to evaluate the prevalence, severity, and characteristics of wheezing in the first year
of life in Latin America and Europe.(
1010. Mallol J, García-Marcos L, Solé D, Brand P; the EISL Study Group.
International prevalence of recurrent wheezing during the first year of life:
variability, treatment patterns and use of health resources. Thorax.
2010;65(11):1004-9.http://dx.doi.org/10.1136/thx.2009.115188
http://dx.doi.org/10.1136/thx.2009.11518...
)
The EISL questionnaire was used in an international multicenter study involving Latin
American countries, Spain, and the Netherlands, having been standardized and validated
for use in all of the aforementioned countries, including Brazil.(
66. Moraes LS, Takanoa AO, Mallol J, Solé D. Risk factors associated with
wheezing in infants. J Pediatr (Rio J).
2013;89(6):559-66.http://dx.doi.org/10.1016/j.jped.2013.04.004
http://dx.doi.org/10.1016/j.jped.2013.04...
,
1010. Mallol J, García-Marcos L, Solé D, Brand P; the EISL Study Group.
International prevalence of recurrent wheezing during the first year of life:
variability, treatment patterns and use of health resources. Thorax.
2010;65(11):1004-9.http://dx.doi.org/10.1136/thx.2009.115188
http://dx.doi.org/10.1136/thx.2009.11518...
,
1414. Mallol J, García-Marcos L, Aguirre V, Martinez-Torres A,
Perez-Fernández V, Gallardo A, et al. The International Study of Wheezing in infants:
questionnaire validation. Int Arch Allergy Immunol.
2007;144(1):44-50.http://dx.doi.org/10.1159/000102613
http://dx.doi.org/10.1159/000102613...
15. Bianca AC, Wandalsen GF, Miyagi K, Camargo L, Cezarin D, Mallol J,
et al. International Study of Wheezing in Infants (EISL): validation of written
questionnaire for children aged below 3 years. J Investig Allergol Clin Immunol.
2009;19(1):35-42.
-
1616. Garcia-Marcos L, Mallol J, Solé D, Brand PL, Sanchez-Bahillo M,
Sanchez-Solis M; et al. Latitude modifies the effect size of factors related to
recurrent wheeze in the first year of life. Respir Med.
2013;107(5):665-72.http://dx.doi.org/10.1016/j.rmed.2013.01.015
http://dx.doi.org/10.1016/j.rmed.2013.01...
)
The objective of the present study was to determine the prevalence of and risk factors for OW and WBS in the first year of life in a sample of infants in the city of Blumenau, Brazil.
Methods
A prospective cross-sectional study was conducted at 43 health care clinics in the city
of Blumenau, the EISL questionnaire being used.(
99. Mallol J, Andrade R, Auger F, Rodriguez J, Alvarado R, Figueroa L.
Wheezing during the first year of life in infants from low-income population: a
descriptive study. Allergol Immunopathol (Madr).
2005;33(5):257-63.http://dx.doi.org/10.1157/13080928
http://dx.doi.org/10.1157/13080928...
10. Mallol J, García-Marcos L, Solé D, Brand P; the EISL Study Group.
International prevalence of recurrent wheezing during the first year of life:
variability, treatment patterns and use of health resources. Thorax.
2010;65(11):1004-9.http://dx.doi.org/10.1136/thx.2009.115188
http://dx.doi.org/10.1136/thx.2009.11518...
11. Visser CA, Garcia-Marcos L, Eggink J, Brand PL. Prevalence and risk
factors of wheeze in Dutch infants in their first year of life. Pediatr Pulmonol.
2010; 45(2):149-56. http://dx.doi.org/10.1002/ppul.21161
http://dx.doi.org/10.1002/ppul.21161 ...
-
1212. Venero-Fernándes SL, Suárez-Medina R, Mora-Faife EC, García-García
G, Valle-Infante I, Gómez-Marrero L, et al. Risk factors for wheezing in infants born
in Cuba. QJM. 2013;106(11):1023-9. http://dx.doi.org/10.1093/qjmed/hct143
http://dx.doi.org/10.1093/qjmed/hct143...
)
In order to calculate the sample size, we used the method used in the EISL,(
1414. Mallol J, García-Marcos L, Aguirre V, Martinez-Torres A,
Perez-Fernández V, Gallardo A, et al. The International Study of Wheezing in infants:
questionnaire validation. Int Arch Allergy Immunol.
2007;144(1):44-50.http://dx.doi.org/10.1159/000102613
http://dx.doi.org/10.1159/000102613...
) considering that the prevalence of wheezing was 25-30%. Taking into account
a power of 95% and an α of 0.01, we calculated that 1,100 infants were required.
The EISL questionnaire consists of 50 questions regarding wheezing, risk factors,
demographic characteristics, and environmental characteristics, having previously been
translated into Brazilian Portuguese and validated for use in the Brazilian
population.(
22. Chong Neto HJ, Rosário NA, Solé D, Mallol J. Prevalence of recurrent
wheezing in infants. J Pediat (Rio J).
2007;83(4):357-62.http://dx.doi.org/10.1590/S0021-75572007000500012
http://dx.doi.org/10.1590/S0021-75572007...
)
The EISL questionnaire was administered by the principal investigator and previously
trained health care clinic staff and was completed by the caregivers of the infants
(age, 12-15 months), in accordance with the method proposed and used in the original
study,(
1414. Mallol J, García-Marcos L, Aguirre V, Martinez-Torres A,
Perez-Fernández V, Gallardo A, et al. The International Study of Wheezing in infants:
questionnaire validation. Int Arch Allergy Immunol.
2007;144(1):44-50.http://dx.doi.org/10.1159/000102613
http://dx.doi.org/10.1159/000102613...
) during visits for routine immunization or routine child care visits to the
health care clinics over a period of 18 months.
All of the infants whose legal guardians gave written informed consent were included in the present study. The study was approved by the Research Ethics Committee of the Fundação Universidade Regional de Blumenau, located in the city of Blumenau (Protocol no. 039/08).
Infants who had previously been diagnosed with genetic disease, neuropathy, myopathy, heart disease, primary or secondary malnutrition, cystic fibrosis, or somatic malformations were excluded, as were those with limited life expectancy. The infants were divided into three groups: the WBS group, comprising infants who had had three or more episodes of wheezing; the OW group, comprising infants who had had fewer than three episodes of wheezing; and the nonwheezing group, comprising infants who had never wheezed.
The data obtained by the EISL questionnaire were coded, entered into a Microsoft Excel(r) 2007 database, and statistically analyzed with the use of the Statistical Package for the Social Sciences, version 18.0 (SPSS Inc., Chicago, IL, USA), for Windows. Bivariate and multivariate logistic regression analyses were used in order to compare risk factors between wheezing and nonwheezing infants, as well as between the OW and WBS groups. The results are presented as OR and 95% CI. The variables that showed significant values for the studied association were described. Values of α < 0.05 were considered statistically significant.
Results
Caregivers of 1,269 infants 12-15 months of age were interviewed. Of those infants, 1,211 (95.43%) were White. In addition, 715 (56.34%) had had episodes of wheezing. Of those 715 infants, 343 (27.03%) had OW and 372 (29.31%) had WBS.
The EISL questionnaire was completed by mothers, fathers, and others in 1,073 (84.55%), 106 (8.35%), and 90 (7.09%), respectively. The age distribution was as follows: 12 months, in 549 (43.26%); 13 months, in 295 (23.25%); 14 months, in 331 (26.08%); and 15 months, in 94 (7.41%).
The risk factors identified and showing positive ORs are described in the figures and tables. Figure 1A and Table 1 show the bivariate analysis for the presence of wheezing in the study population. Figure 1B and Table 1 show the multivariate analysis for the presence of wheezing in the study population. Figures 1A/B and Table 1 show data for the sample as a whole, comparisons being made between wheezing infants (the OW and WBS groups taken together) and nonwheezing infants. Table 1 shows the distribution of risk factors for wheezing, together with their respective ORs and 95% CIs, among the infants studied.
Factors associated with wheezing in the first 12 months of life (wheezing infants, n = 715; nonwheezing infants, n = 554; total, n = 1,269). In A, bivariate logistic regression analysis; in B, multivariate logistic regression analysis.
Factors associated with wheezing in the first year of life (wheezing infants, n = 715; nonwheezing infants, n = 554; total, n = 1,269).
The multivariate analysis showed that certain risk factors remained. Figures 2A and 2B show the bivariate and multivariate analyses of risk factors for WBS, respectively. A comparison was made between the OW and WBS groups. Table 2 shows the distribution of risk factors for recurrent wheezing, together with their respective ORs and 95% CIs, among the infants studied.
Factors associated with wheezing in the first year of life (wheezing infants, n = 715; nonwheezing infants, n = 554; total, n = 1,269).
Factors associated with recurrent wheezing in the first year of life (occasional wheezing, n = 343; persistent wheezing, n = 232; total, n = 715).
Discussion
The present study was the first to determine the prevalence of and risk factors for
wheezing in infants in the state of Santa Catarina, Brazil. In comparison with other
studies conducted in Brazil and using the EISL questionnaire, ours showed the highest
prevalence of wheezing in the first year of life. The prevalence of wheezing in infants
was found to be 43% in the city of Recife,(
77. Medeiros D, Silva AR, Rizzo JA, Sarinho E, Mallol J, Sole D.
Prevalence of wheezing and associated risk factors among infants in Recife,
Pernambuco State, Brazil [Article in Portuguese]. Cad Saude Publica.
2011;27(8):1551-9. http://dx.doi.org/10.1590/S0102-311X2011000800010
http://dx.doi.org/10.1590/S0102-311X2011...
) 43.2% in the city of Cuiabá,(
88. Rosa AM, Jacobson Lda S, Botelho C, Ignotti E. Prevalence of wheezing
and associated factors in children under 5 years of age in Cuiabá, Mato Grosso State,
Brazil [Article in Portuguese]. Cad Saude Publica. 2013;29(9):1816-28.
http://dx.doi.org/10.1590/S0102-311X2013001300021
http://dx.doi.org/10.1590/S0102-311X2013...
) 45.4% in the city of Curitiba,(
33. Chong Neto HJ, Rosário NA; Grupo EISL Curitiba (Estudio Internacional
de Sibilancias en Lactantes). Risk factors for wheezing in the first year of life. J
Pediatr (Rio J). 2008;84(6):495-502.
http://dx.doi.org/10.1590/S0021-75572008000700005
http://dx.doi.org/10.1590/S0021-75572008...
) and 46% in the city of São Paulo.(
44. Dela Bianca AC, Wandalsen GF, Mallol J, Solé D. Prevalence and
severity of wheezing in the first year of life. J Bras Pneumol.
2010;36(4):402-9.http://dx.doi.org/10.1590/S1806-37132010000400003
http://dx.doi.org/10.1590/S1806-37132010...
) The prevalence rates of OW and WBS were as follows: 22,7% and 22.6%,
respectively, in Curitiba(
22. Chong Neto HJ, Rosário NA, Solé D, Mallol J. Prevalence of recurrent
wheezing in infants. J Pediat (Rio J).
2007;83(4):357-62.http://dx.doi.org/10.1590/S0021-75572007000500012
http://dx.doi.org/10.1590/S0021-75572007...
); 19,4% and 26.6%, respectively, in São Paulo(
55. Dela Bianca A, Wandalsen G, Mallol J, Sole D. Risk factors for
wheezing disorders in infants in the first year of life living in São Paulo, Brazil.
J Trop Pediatr. 2012;58(6):501-4. http://dx.doi.org/10.1093/tropej/fms016
http://dx.doi.org/10.1093/tropej/fms016...
); 54.1% and 45,9%, respectively, in Cuiabá(
66. Moraes LS, Takanoa AO, Mallol J, Solé D. Risk factors associated with
wheezing in infants. J Pediatr (Rio J).
2013;89(6):559-66.http://dx.doi.org/10.1016/j.jped.2013.04.004
http://dx.doi.org/10.1016/j.jped.2013.04...
); and 61% and 20%, respectively, in Porto Alegre.(
1717. Lima JA, Fischer GB, Sarria EE, Mattiello R, Solé D. Prevalence of
and risk factors for wheezing in the first year of life. J Bras Pneumol.
2010;36(5):525-31.
) In the present study, they were 27,00% and 29.31%, respectively. In Latin
America, Europe, and the Netherlands, the prevalence rates of wheezing in infants were
found to be 21.4%, 15.0%, and 14.5%, respectively,(
1010. Mallol J, García-Marcos L, Solé D, Brand P; the EISL Study Group.
International prevalence of recurrent wheezing during the first year of life:
variability, treatment patterns and use of health resources. Thorax.
2010;65(11):1004-9.http://dx.doi.org/10.1136/thx.2009.115188
http://dx.doi.org/10.1136/thx.2009.11518...
,
1111. Visser CA, Garcia-Marcos L, Eggink J, Brand PL. Prevalence and risk
factors of wheeze in Dutch infants in their first year of life. Pediatr Pulmonol.
2010; 45(2):149-56. http://dx.doi.org/10.1002/ppul.21161
http://dx.doi.org/10.1002/ppul.21161 ...
) being lower than the prevalence rate found in the present study.
Social, economic, and environmental characteristics, as well as climate and latitude,
have been reported as reasons for the differences in prevalence rates across
studies.(
1010. Mallol J, García-Marcos L, Solé D, Brand P; the EISL Study Group.
International prevalence of recurrent wheezing during the first year of life:
variability, treatment patterns and use of health resources. Thorax.
2010;65(11):1004-9.http://dx.doi.org/10.1136/thx.2009.115188
http://dx.doi.org/10.1136/thx.2009.11518...
,
1616. Garcia-Marcos L, Mallol J, Solé D, Brand PL, Sanchez-Bahillo M,
Sanchez-Solis M; et al. Latitude modifies the effect size of factors related to
recurrent wheeze in the first year of life. Respir Med.
2013;107(5):665-72.http://dx.doi.org/10.1016/j.rmed.2013.01.015
http://dx.doi.org/10.1016/j.rmed.2013.01...
)
In the present study, the risk factors for OW and WBS were similar to those reported in
other studies conducted in Brazil.(
22. Chong Neto HJ, Rosário NA, Solé D, Mallol J. Prevalence of recurrent
wheezing in infants. J Pediat (Rio J).
2007;83(4):357-62.http://dx.doi.org/10.1590/S0021-75572007000500012
http://dx.doi.org/10.1590/S0021-75572007...
3. Chong Neto HJ, Rosário NA; Grupo EISL Curitiba (Estudio Internacional
de Sibilancias en Lactantes). Risk factors for wheezing in the first year of life. J
Pediatr (Rio J). 2008;84(6):495-502.
http://dx.doi.org/10.1590/S0021-75572008000700005
http://dx.doi.org/10.1590/S0021-75572008...
4. Dela Bianca AC, Wandalsen GF, Mallol J, Solé D. Prevalence and
severity of wheezing in the first year of life. J Bras Pneumol.
2010;36(4):402-9.http://dx.doi.org/10.1590/S1806-37132010000400003
http://dx.doi.org/10.1590/S1806-37132010...
5. Dela Bianca A, Wandalsen G, Mallol J, Sole D. Risk factors for
wheezing disorders in infants in the first year of life living in São Paulo, Brazil.
J Trop Pediatr. 2012;58(6):501-4. http://dx.doi.org/10.1093/tropej/fms016
http://dx.doi.org/10.1093/tropej/fms016...
6. Moraes LS, Takanoa AO, Mallol J, Solé D. Risk factors associated with
wheezing in infants. J Pediatr (Rio J).
2013;89(6):559-66.http://dx.doi.org/10.1016/j.jped.2013.04.004
http://dx.doi.org/10.1016/j.jped.2013.04...
-
77. Medeiros D, Silva AR, Rizzo JA, Sarinho E, Mallol J, Sole D.
Prevalence of wheezing and associated risk factors among infants in Recife,
Pernambuco State, Brazil [Article in Portuguese]. Cad Saude Publica.
2011;27(8):1551-9. http://dx.doi.org/10.1590/S0102-311X2011000800010
http://dx.doi.org/10.1590/S0102-311X2011...
) Our study showed an association of WBS with upper and lower airway
infections. It is known that infants have many episodes of viral infection,(
1818. Busse WW, Lemanske RF Jr, Gern JE. Role of viral respiratory
infections in asthma and asthma exacerbations. Lancet.
2010;376(9743):826-34.http://dx.doi.org/10.1016/S0140-6736(10)61380-3
http://dx.doi.org/10.1016/S0140-6736(10)...
19. Wu P, Dupont WD, Griffin MR, Carroll KN, Mitchel EF, Gebretsadik T,
et al. Evidence of a causal role of winter virus infection during infancy in early
childhood asthma. Am J Respir Crit Care Med.
2008;178(11):1123-9.http://dx.doi.org/10.1164/rccm.200804-579OC
http://dx.doi.org/10.1164/rccm.200804-57...
20. Jackson DJ, Gangnon RE, Evans MD, Roberg KA, Anderson EL, Pappas TE,
et al. Wheezing rhinovirus illnesses in early life predict asthma development in
high-risk children. Am J Respir Crit Care Med.
2008;178(7):667-72.http://dx.doi.org/10.1164/rccm.200802-309OC
http://dx.doi.org/10.1164/rccm.200802-30...
-
2121. Kusel MM, de Klerk NH, Kebadze T, Vohma V, Holt PG, Johnston SL, et
al. Early-life respiratory viral infections, atopic sensitization, and risk of
subsequent development of persistent asthma. J Allergy Clin Immunol.
2007;119(5):1105-10.http://dx.doi.org/10.1016/j.jaci.2006.12.669
http://dx.doi.org/10.1016/j.jaci.2006.12...
) and that OW and WBS are associated with many viruses. For most children,
episodes of wheezing associated with respiratory infections decrease with age; however,
for some, wheezing attacks early in life can mark the beginning of asthma.(
1818. Busse WW, Lemanske RF Jr, Gern JE. Role of viral respiratory
infections in asthma and asthma exacerbations. Lancet.
2010;376(9743):826-34.http://dx.doi.org/10.1016/S0140-6736(10)61380-3
http://dx.doi.org/10.1016/S0140-6736(10)...
19. Wu P, Dupont WD, Griffin MR, Carroll KN, Mitchel EF, Gebretsadik T,
et al. Evidence of a causal role of winter virus infection during infancy in early
childhood asthma. Am J Respir Crit Care Med.
2008;178(11):1123-9.http://dx.doi.org/10.1164/rccm.200804-579OC
http://dx.doi.org/10.1164/rccm.200804-57...
20. Jackson DJ, Gangnon RE, Evans MD, Roberg KA, Anderson EL, Pappas TE,
et al. Wheezing rhinovirus illnesses in early life predict asthma development in
high-risk children. Am J Respir Crit Care Med.
2008;178(7):667-72.http://dx.doi.org/10.1164/rccm.200802-309OC
http://dx.doi.org/10.1164/rccm.200802-30...
-
2121. Kusel MM, de Klerk NH, Kebadze T, Vohma V, Holt PG, Johnston SL, et
al. Early-life respiratory viral infections, atopic sensitization, and risk of
subsequent development of persistent asthma. J Allergy Clin Immunol.
2007;119(5):1105-10.http://dx.doi.org/10.1016/j.jaci.2006.12.669
http://dx.doi.org/10.1016/j.jaci.2006.12...
)
Viral respiratory infections can have serious adverse effects in patients with asthma
and account for nearly 80% of all episodes of asthma exacerbation in children and in
adults. Whether respiratory infections determine the progression of WBS or the severity
of the disease remains unclear. It has been established that some viruses induce asthma,
whereas others confer protection against it.(
2020. Jackson DJ, Gangnon RE, Evans MD, Roberg KA, Anderson EL, Pappas TE,
et al. Wheezing rhinovirus illnesses in early life predict asthma development in
high-risk children. Am J Respir Crit Care Med.
2008;178(7):667-72.http://dx.doi.org/10.1164/rccm.200802-309OC
http://dx.doi.org/10.1164/rccm.200802-30...
) Follow-up studies have shown that the timing of birth in relation to the
winter virus peak is associated with an increased risk of developing WBS and
asthma.(
1818. Busse WW, Lemanske RF Jr, Gern JE. Role of viral respiratory
infections in asthma and asthma exacerbations. Lancet.
2010;376(9743):826-34.http://dx.doi.org/10.1016/S0140-6736(10)61380-3
http://dx.doi.org/10.1016/S0140-6736(10)...
19. Wu P, Dupont WD, Griffin MR, Carroll KN, Mitchel EF, Gebretsadik T,
et al. Evidence of a causal role of winter virus infection during infancy in early
childhood asthma. Am J Respir Crit Care Med.
2008;178(11):1123-9.http://dx.doi.org/10.1164/rccm.200804-579OC
http://dx.doi.org/10.1164/rccm.200804-57...
20. Jackson DJ, Gangnon RE, Evans MD, Roberg KA, Anderson EL, Pappas TE,
et al. Wheezing rhinovirus illnesses in early life predict asthma development in
high-risk children. Am J Respir Crit Care Med.
2008;178(7):667-72.http://dx.doi.org/10.1164/rccm.200802-309OC
http://dx.doi.org/10.1164/rccm.200802-30...
-
2121. Kusel MM, de Klerk NH, Kebadze T, Vohma V, Holt PG, Johnston SL, et
al. Early-life respiratory viral infections, atopic sensitization, and risk of
subsequent development of persistent asthma. J Allergy Clin Immunol.
2007;119(5):1105-10.http://dx.doi.org/10.1016/j.jaci.2006.12.669
http://dx.doi.org/10.1016/j.jaci.2006.12...
) Such studies suggest that children who are at an increased risk of
developing acute viral bronchiolitis are also more likely to develop WBS and
asthma.(
1717. Lima JA, Fischer GB, Sarria EE, Mattiello R, Solé D. Prevalence of
and risk factors for wheezing in the first year of life. J Bras Pneumol.
2010;36(5):525-31.
18. Busse WW, Lemanske RF Jr, Gern JE. Role of viral respiratory
infections in asthma and asthma exacerbations. Lancet.
2010;376(9743):826-34.http://dx.doi.org/10.1016/S0140-6736(10)61380-3
http://dx.doi.org/10.1016/S0140-6736(10)...
19. Wu P, Dupont WD, Griffin MR, Carroll KN, Mitchel EF, Gebretsadik T,
et al. Evidence of a causal role of winter virus infection during infancy in early
childhood asthma. Am J Respir Crit Care Med.
2008;178(11):1123-9.http://dx.doi.org/10.1164/rccm.200804-579OC
http://dx.doi.org/10.1164/rccm.200804-57...
20. Jackson DJ, Gangnon RE, Evans MD, Roberg KA, Anderson EL, Pappas TE,
et al. Wheezing rhinovirus illnesses in early life predict asthma development in
high-risk children. Am J Respir Crit Care Med.
2008;178(7):667-72.http://dx.doi.org/10.1164/rccm.200802-309OC
http://dx.doi.org/10.1164/rccm.200802-30...
-
2121. Kusel MM, de Klerk NH, Kebadze T, Vohma V, Holt PG, Johnston SL, et
al. Early-life respiratory viral infections, atopic sensitization, and risk of
subsequent development of persistent asthma. J Allergy Clin Immunol.
2007;119(5):1105-10.http://dx.doi.org/10.1016/j.jaci.2006.12.669
http://dx.doi.org/10.1016/j.jaci.2006.12...
)
In our study, the risk of OW and WBS was found to be higher in the infants who attended
daycare than in those who did not. Parents and physicians know that attending daycare in
the first two years of life is a risk factor for recurrent respiratory infections. This
has been extensively studied. In contrast, conflicting results indicate that the risk of
developing asthma is higher(
2222. Sun Y, Sundell J. Early daycare attendance increase the risk for
respiratory infections and asthma of children. J Asthma.
2011;48(8):790-6.http://dx.doi.org/10.3109/02770903.2011.604884
http://dx.doi.org/10.3109/02770903.2011....
,
2323. Caudri D, Wijga A, Scholtens S, Kerkhof M , Gerritsen J, Ruskamp JM,
et al. Early daycare is associated with an increase in airway symptoms in early
childhood but is no protection against asthma or atopy at 8 years. Am J Respir Crit
Care Med. 2009;180(6):491-8. http://dx.doi.org/10.1164/rccm.200903-0327OC
http://dx.doi.org/10.1164/rccm.200903-03...
) or lower(
2424. Ball TM, Castro-Rodriguez JA, Griffith KA, Holberg CJ, Martinez FD,
Wright AL. Siblings, day-care attendance, and the risk of asthma and wheezing during
childhood. N Engl J Med.
2000;343(8):538-43.http://dx.doi.org/10.1056/NEJM200008243430803
http://dx.doi.org/10.1056/NEJM2000082434...
,
2525. Gaffin JM, Spergel JM, Boguniewicz M, Eichenfield LF, Paller AS,
Fowler JF Jr, et al. Effect of cat and daycare exposures on the risk of asthma in
children with atopic dermatitis. Allergy Asthma Proc.
2012;33(3):282-8.http://dx.doi.org/10.2500/aap.2012.33.3572
http://dx.doi.org/10.2500/aap.2012.33.35...
) in infants who attend daycare or have older siblings than in those who do
not. Therefore, attending daycare as a risk factor for WBS is intriguing because it
appears to have contrasting effects. On the one hand, if attending daycare is associated
with the presence of recurrent wheezing, the long-term prognosis of such patients is
probably good. On the other hand, if attending daycare is a risk factor for severe
wheezing, this implies an increased risk of developing asthma. Therefore, long-term
studies involving virus isolation are needed in order to clarify the role of attending
daycare as a risk factor for persistent wheezing.(
1111. Visser CA, Garcia-Marcos L, Eggink J, Brand PL. Prevalence and risk
factors of wheeze in Dutch infants in their first year of life. Pediatr Pulmonol.
2010; 45(2):149-56. http://dx.doi.org/10.1002/ppul.21161
http://dx.doi.org/10.1002/ppul.21161 ...
)
Our data indicate that male infants are more likely to wheeze than are female infants.
This has been verified in other studies, and it is known that, in comparison with girls,
boys have narrower airways, greater sensitization to aeroallergens, and higher IgE
levels early in life.(
2626. Sherrill DL, Stein R, Halonen M, Holberg CJ, Wright A, Martinez FD.
Total serum IgE and its association with asthma symptoms and allergic sensitization
among children. J Allergy Clin Immunol.
1999;104(1):28-36.http://dx.doi.org/10.1016/S0091-6749(99)70110-7
http://dx.doi.org/10.1016/S0091-6749(99)...
) However, although the prevalence of recurrent wheezing is higher in boys,
it decreases as they grow older and reach adolescence.(
11. Martinez FD, Wright AL, Taussig LM, Holberg CJ, Halonen M, Morgan WJ.
Asthma and wheezing in the first six years of life. The Group Health Medical
Associates. N Engl J Med.
1995;332(3):133-8.http://dx.doi.org/10.1056/NEJM199501193320301
http://dx.doi.org/10.1056/NEJM1995011933...
,
2727. van Merode T, Maas T, Twellaar M, Kester A, van Schayck CP.
Gender-specific differences in the prevention of asthma-like symptoms in high-risk
infants. Pediatr Allergy Immunol.
2007;18(3):196-200.http://dx.doi.org/10.1111/j.1399-3038.2006.00513.x
http://dx.doi.org/10.1111/j.1399-3038.20...
)
Although we did not evaluate the severity of wheezing in the present study, an
increasing number of studies have shown the importance of breastfeeding, especially in
protecting against severe wheezing episodes in infants. A study evaluating 12,474
children with bronchiolitis, 1,588 of whom required hospitalization, showed that infants
whose mothers had not initiated breastfeeding in the maternity ward were at an increased
risk of hospitalization for viral bronchiolitis.(
2828. Koehoorn M, Karr CJ, Demers PA, Lencar C, Tamburic L, Brauer M.
Descriptive epidemiological features of bronchiolitis in a population-based
cohort.Pediatrics. 2008;122(6):1196-203. http://dx.doi.org/10.1542/peds.2007-2231
http://dx.doi.org/10.1542/peds.2007-2231...
)
One group of authors studied a group of infants hospitalized for acute viral bronchiolitis and noted that the duration of breastfeeding was inversely related to the duration of oxygen use and hospitalization, having reported that, for each month of breastfeeding, there was an 11-h reduction in the duration of oxygen use. ( 2929. Dornelles CT, Piva JP, Marostica PJ. Nutritional status, breastfeeding, and evolution of Infants with acute viral bronchiolitis. J Health Popul Nutr. 2007;25(3):336-43. ) Therefore, mothers should be encouraged to prolong breastfeeding and to keep infants under 6 months of age out of daycare.
Another group of authors(
3030. Dotterud CK, Storrø O, Simpson MR, Johnsen R, Øien T. The impact of
pre- and postnatal exposures on allergy related diseases in childhood: a controlled
multicentre intervention study in primary health care. BMC Public Health.
2013;13:123.http://dx.doi.org/10.1186/1471-2458-13-123
http://dx.doi.org/10.1186/1471-2458-13-1...
) found that reduced tobacco exposure and increased intake of oily fish
during pregnancy and early childhood can be effective in reducing the incidence of
asthma at two years of age. The differential impact on boys and girls suggests that the
pathophysiology of asthma depends on the gender of the children.
One of the risk factors for WBS and asthma in children is a family history of atopy and allergies. In our study, we found that the infants whose parents had asthma and allergies were more likely to have episodes of OW and WBS than were those whose parents had no family history of asthma or allergies. This finding suggests that genetic factors play an important role in OW and WBS.
One limitation of the present study is that we did not address risk factors that might be specific to the study population. However, this provides an opportunity for studies investigating daycare attendance and the presence/absence of older siblings.
In conclusion, the prevalence rate of wheezing in infants in the city of Blumenau was 56.34%, of which 27.31% and 29.31% of OW and WBS, respectively. The etiology was multifactorial, and the risk factors were intrinsic and extrinsic, including respiratory tract infections, having a parent with allergies, attending daycare, and early wheezing. The high prevalence of WBS and the intrinsic risk factors indicate the need and the opportunity for epidemiological and genetic studies in this population.
References
-
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» http://dx.doi.org/10.1056/NEJM199501193320301 -
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» http://dx.doi.org/10.1590/S0021-75572007000500012 -
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» http://dx.doi.org/10.1590/S0021-75572008000700005 -
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» http://dx.doi.org/10.1016/j.rmed.2013.01.015 -
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-
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» http://dx.doi.org/10.1016/S0140-6736(10)61380-3 -
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» http://dx.doi.org/10.1164/rccm.200804-579OC -
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Financial support: None
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*
Study carried out in the Department of Pediatrics, State University at Campinas School of Medical Sciences, Campinas, Brazil
Publication Dates
-
Publication in this collection
Nov-Dec 2014
History
-
Received
24 Feb 2014 -
Accepted
24 Sept 2014