Juvenile household contacts aged 15 or younger of patients with pulmonary TB in the greater metropolitan area of Vitória, Brazil: a cohort study.
OBJECTIVE
To compare clinical, radiological and laboratory aspects of household contacts, aged 15 or younger, of patients presenting a positive culture for Mycobacterium tuberculosis.


METHODS
This was a cohort study comparing children and adolescents (< or = 15 years of age) who were household contacts of TB cases presenting positive sputum smear and positive culture results (exposed group, n = 100) or negative sputum smear and positive culture results (unexposed group, n = 55). All of the contacts were evaluated via the TB control program of a university hospital in the city of Vitória, Brazil, between July of 2003 and December of 2006.


RESULTS
Of the 155 minors evaluated, 87 (56.1%) were female and 68 (43.9%) were male. Of those 155, 28 (18%) were aged 5 or younger, 62 (40%) were aged 5-9, and 65 (42%) were aged 10-15. Symptoms of the disease were found in 17 (17%) of the 100 contacts in the exposed group and in 9 (16%) of the 55 in the unexposed group (p = 0.86). Chest X-rays showed alterations in 20 (21%) and 2 (4%) of the contacts in the exposed and unexposed groups, respectively (RR = 6.9; p = 0.004). In the exposed and unexposed groups, respectively, 35 (38%) and 10 (18%) of the contacts presented positive results in the tuberculin skin test (RR = 2.8; p = 0.01). Of the 100 contacts in the exposed group, 5 (5%) were diagnosed with TB, which was not diagnosed in any of those in the unexposed group (p = 0.08).


CONCLUSIONS
Although no significant difference was found between the two groups regarding the incidence of TB, it is of note that there is a greater risk of becoming infected with M. tuberculosis if the bacterial load of the index case is high.
Maciel
Ethel Leonor Noia
EL
Infectious Diseases Center, Health Sciences Center, Federal University of Espírito Santo, Vitória, Brazil. emaciel@ndi.ufes.br
Vieira
Luiza Werner Heringer
LW
Molina
Lucília Pereira Dutra
LP
Alves
Rosana
R
Prado
Thiago Nascimento do
TN
Dietze
Reynaldo
R
D000293:Adolescent; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D016358:Contact Tracing; D005191:Family Characteristics; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009169:Mycobacterium tuberculosis; D011859:Radiography; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000000981:diagnostic imaging / Q000517:prevention & control / Q000635:transmission*; D014505:Urban Population