[Dengue fever in three sanitary districts in the city of Belo Horizonte, Brazil: a population-based seroepidemiological survey, 2006 to 2007].
OBJECTIVE
To determine the seroprevalence of dengue fever serotypes in three sanitary districts in the city of Belo Horizonte and investigate the association of seroprevalence with contextual and individual variables.


METHODS
The survey was conducted in the sanitary districts of Venda Nova, Leste and Centro-Oeste between June 2006 and March 2007. All residents aged 1 year or older were eligible for the study. Participants answered a questionnaire and had a 5 mL blood sample collected to determine the presence of anti-dengue types 1, 2, and 3 virus antibodies by seroneutralization. The questionnaire covered demographic aspects, socioeconomic status, physical characteristics of the home, residential mobility between cities, previous history of signs and symptoms associated with dengue fever, and knowledge concerning dengue fever prevention measures, among others.


RESULTS
Seroprevalence was 11.9% (95%CI: 9.7-14.6) among the 709 individuals included in the study, and it was not associated with sex, age, family income, and having moved to another town in the past 10 years. Seropositivity was associated with type of construction (apartment or house/shanty, with apartment being a protection factor) and with an elevated health vulnerability index where the dwelling was located.


CONCLUSIONS
In this study, seroprevalence was lower than in previous studies carried out in mid-size and large Brazilian cities. This suggests that Belo Horizonte has employed efficient control measures. However, heterogeneity within the city was observed in terms of dengue fever transmission, which was largely associated with contextual indicators of vulnerability. The number of susceptibles is still high, and the control of dengue fever remains a difficult public health issue.
Prefeitura Municipal de Belo Horizonte, Secretaria Municipal de Saúde, Belo Horizonte, MG, Brasil, 30170-122.
José Eduardo Marques
JE
Pessanha
Waleska Teixeira
WT
Caiaffa
Erna Gessien
EG
Kroon
Fernando Augusto
FA
Proietti
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003715:Dengue / Q000453:epidemiology* / Q000635:transmission; D003716:Dengue Virus / Q000145:classification / Q000276:immunology / Q000302:isolation & purification; D005260:Female; D006801:Humans; D007182:Income; D007223:Infant; D008297:Male; D008875:Middle Aged; D012111:Residence Characteristics; D016036:Seroepidemiologic Studies; D012703:Serotyping; D012959:Socioeconomic Factors; D014504:Urban Health; D055815:Young Adult
D000914:Antibodies, Viral