Prevalence of anti-tuberculosis drug resistance in an HIV/AIDS reference hospital in Rio de Janeiro, Brazil

SETTING

A reference hospital for tuberculosis (TB) and human immunodeficiency virus/acquired immune-deficiency syndrome (HIV/AIDS) with a TB control programme in Rio de Janeiro, Brazil.

OBJECTIVE

To estimate the prevalence of resistance to anti-tuberculosis drugs and to identify associated factors.

DESIGN

In a cross-sectional study, clinical and laboratory data were collected retrospectively from 2001 to 2005. Patients with isolation of Mycobacterium tuberculosis and available drug susceptibility tests were considered eligible. Data on demographic characteristics, risk factors for resistance, HIV serology and past TB history were collected and analysed by chi(2) Mann-Whitney test and Poisson regression.

RESULTS

We analysed 350 treatments, of which 62 were for patients with previous TB. HIV status was positive in 31.2% of cases. Resistance was found in 15.7% and multidrug resistance (MDR) in 4.3% of cases. Previous treatment (P < 0.001) and relapse within 2 years were associated with resistance (P < 0.03). Pulmonary cavities were associated with MDR (P < 0.001). Homelessness was associated with any resistance in newly diagnosed patients (P < 0.01). Working in a hospital was not associated with resistance.

CONCLUSION

Suspicion of drug-resistant disease is necessary in patients with a history of previous TB in hospitals in Rio de Janeiro. The implementation of an effective hospital TB control programme can prevent transmission even in high TB prevalence settings.

International Study of Asthma and Allergies in Childhood (ISAAC): prevalence of asthma and asthma-related symptoms among Brazilian schoolchildren

We have studied the prevalence of asthma and its symptoms using a standard written questionnaire (WQ) designed for the International Study of Asthma and Allergies in Children (ISAAC). The WQ (questions 1 through 8 related to asthma) was applied to 13,604 children aged 6-7 years from six Brazilian cities: Porto Alegre (South, N = 2,976), Curitiba (South, N = 1,664), São Paulo (Southeast, N = 3,005), Uberlândia (Southeast, N = 3,002), Itabira (Southeast, N = 1,551) and Recife (Northeast, N = 1,406). At the age of 13-14 years the WQ was applied to 20,554 schoolchildren living in Porto Alegre (South, N = 3,198), Curitiba (South, N = 3,008), São Paulo (Southeast, N = 3,008), Uberlândia (Southeast, N = 3,001), Itabira (Southeast, N = 2,134), Salvador (Northeast, N = 3,119) and Recife (Northeast, N = 3,086). The parents of the younger children answered the WQ, whereas the adolescents answered the questionnaire themselves. The response rates were 72% and 93% for the 6-7-year-old children and for the 13-14-year-old children, respectively. There was a slight predominance of male children in the population studied. In the group of 6-7-year-olds, the prevalence of physician diagnosed asthma was 7.3% for boys and 4.9% for girls: in the group of 13-14-year-olds the rates were 9.8% and 10.2%, respectively. Asthma severity was similar for both age groups, and wheezing following exercise was more frequent among the adolescents. In keeping with studies from other parts of the world, comparison between reported symptoms and diagnosed asthma revealed a significantly lower frequency of diagnosed asthma, suggesting that in the study population, asthma is underdiagnosed.

Breastfeeding and asthma among Brazilian children

We examined the association of breastfeeding and the presence of chronic respiratory symptoms among 5,182 Brazilian schoolchildren 7-14 years of age who were participants in the International Study on Asthma and Allergies in Childhood (ISAAC). The prevalence of medically diagnosed asthma and current wheeze were respectively 4.6% (95% confidence interval [CI] 4.0%-5.2%) and 11.9% (95% CI 11.0%-12.8%). Ninety percent of the mothers in our study population had breastfed their child. After adjusting for potential confounding factors, we found that children who had not been breastfed were more likely to have a medical diagnosis of asthma (odds ration [OR] = 1 .51, 95% CI 1.00-2.51), experience current wheeze (OR = 1.29, 95% CI 0.96-1.74), and wheeze after exercise (OR = 1.51, 95% CI 1.01-2.27) than children who had been breastfed for more than 6 months. This effect was only present among children with no family history of asthma (OR = 1.54, 95% CI 0.90-2.42 for medical diagnosis of asthma; OR = 1.27, 95% CI 0.93-1.75 for current wheezing; and OR = 1.74, 95% CI 1.12-2.6 for wheeze after exercise). We conclude that the low prevalence of asthma and wheeze observed in our population may be partly related to the high level of breastfeeding.

Prevalence of asthma and other childhood allergies in Brazilian schoolchildren

We determined the prevalence of asthma, rhinitis, and eczema among Brazilian children using the standardized protocol of the International Study on Asthma and Allergies in Childhood (ISAAC) to facilitate the comparison of our results with other studies using the ISAAC methodology. We conducted a cross-sectional study from June to October 1994 to determine the prevalence of asthma, rhinitis, and eczema in 5182 school children aged 7-8 years and 13-14 years residing in the Brazilian towns of Santa Maria and Itabira (iron-mining cities located in Minas Gerais). Parents completed questionnaires at their child's school in the presence of trained interviewers. The cumulative prevalence of doctor-diagnosed asthma was 4.6% for all ages with no significant difference between the age groups. In general, there was a higher prevalence of symptoms in the younger age group than the older. The prevalence of wheezing in the previous 12 months was 14.3% (7-8 years old) and 9.3% (13-14 years old) (p < 0.01), of chronic cough in the previous 12 months was 25.6% (7-8 years old) and 22.1% (13-14 years old) (p < 0.01), and of nighttime cough in the previous 12 months was 22.3% (7-8 years old) and 19.4% (13-14 years old) (p < 0.05). Overall the prevalences of asthma and wheezing symptoms in the previous 12 months were higher for boys than girls (5.2% vs. 3.9% for asthma, p < 0.01, and 13.2% vs. 10.6% for wheezing, p < 0.01, respectively). These results suggest that asthma-related respiratory illnesses affect a substantial part of the childhood population in Itabira and Santa Maria, Minas Gerais. Some factors such as male gender and younger age may be associated with an increase risk for chronic respiratory symptoms. Prevalences of asthma and allergic diseases in these Brazilian cities on the basis of self-reporting of symptoms and of one's medical history may more accurately portray the true prevalence of asthma than the use of medical records.