Social class based on occupation is associated with hospitalization for A(H1N1)pdm09 infection. Comparison between hospitalized and ambulatory cases.
This study aimed to analyse the existence of an association between social class (categorized by type of occupation) and the occurrence of A(H1N1)pmd09 infection and hospitalization for two seasons (2009-2010 and 2010-2011). This multicentre study compared ambulatory A(H1N1)pmd09 confirmed cases with ambulatory controls to measure risk of infection, and with hospitalized A(H1N1)pmd09 confirmed cases to asses hospitalization risk. Study variables were: age, marital status, tobacco and alcohol use, pregnancy, chronic obstructive pulmonary disease, chronic respiratory failure, cardiovascular disease, diabetes, chronic liver disease, body mass index >40, systemic corticosteroid treatment and influenza vaccination status. Occupation was registered literally and coded into manual and non-manual worker occupational social class groups. A conditional logistic regression analysis was performed. There were 720 hospitalized cases, 996 ambulatory cases and 1062 ambulatory controls included in the study. No relationship between occupational social class and A(H1N1)pmd09 infection was found [adjusted odds ratio (aOR) 0·97, 95% confidence interval (CI) 0·74-1·27], but an association (aOR 1·53, 95% CI 1·01-2·31) between occupational class and hospitalization for A(H1N1)pmd09 was observed. Influenza vaccination was a protective factor for A(H1N1)pmd09 infection (aOR 0·41, 95% CI 0·23-0·73) but not for hospitalization. We conclude that manual workers have the highest risk of hospitalization when infected by influenza than other occupations but they do not have a different probability of being infected by influenza.
Universitat de Lleida,Departament de Cirurgia,Lleida,Spain.
J
J
Pujol
Universitat de Lleida,Departament de Cirurgia,Lleida,Spain.
P
P
Godoy
CIBER Epidemiología y Salud Pública (CIBERESP),Madrid,Spain.
N
N
Soldevila
CIBER Epidemiología y Salud Pública (CIBERESP),Madrid,Spain.
J
J
Castilla
CIBER Epidemiología y Salud Pública (CIBERESP),Madrid,Spain.
F
http://orcid.org/0000-0002-0879-5798
F
González-Candelas
CIBER Epidemiología y Salud Pública (CIBERESP),Madrid,Spain.
J M
JM
Mayoral
CIBER Epidemiología y Salud Pública (CIBERESP),Madrid,Spain.
J
J
Astray
Unidad de Investigación,Hospital Galdakao-Usansolo,Bizkaia,REDISSEC,Spain.
S
S
Garcia
CIBER Epidemiología y Salud Pública (CIBERESP),Madrid,Spain.
V
V
Martin
CIBER Epidemiología y Salud Pública (CIBERESP),Madrid,Spain.
S
S
Tamames
CIBER Epidemiología y Salud Pública (CIBERESP),Madrid,Spain.
M
M
Delgado
Departament de Salut Pública,Universitat de Barcelona,Barcelona,Spain.
A
A
Domínguez
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000502:physiology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D009790:Occupations; D015995:Prevalence; D012307:Risk Factors; D012621:Seasons; D012923:Social Class; D013030:Spain / Q000453:epidemiology; D055815:Young Adult
Influenza A; outbreaks; public health; public health emerging infections; vaccination (immunization)