Microbiological criteria in non-tuberculous mycobacteria pulmonary disease: a tool for diagnosis and epidemiology

SETTING

The value of microbiological criteria in diagnosing non-tuberculous mycobacteria pulmonary disease (NTM-PD) and monitoring its epidemiology is unknown.

OBJECTIVES

To correlate the rate of NTM-PD based on microbiological criteria (American Thoracic Society/Infectious Diseases Society of America [ATS/IDSA] or stricter microbiological criteria) compared with the full ATS/IDSA criteria, to assess the positive predictive value (PPV) of different microbiological criteria in predicting NTM-PD, and to evaluate the clinical relevance of different NTM species.

DESIGN

Retrospective study of all patients with pulmonary NTM isolates in Croatia during an 8-year period. NTM species were divided into low, intermediate and high clinical relevance groups for additional analyses.

RESULTS

Good correlation between both microbiological and full ATS/IDSA criteria was observed. The PPV of stricter and ATS/IDSA microbiological criteria was respectively 93.3% and 59.8%. The usefulness of microbiological criteria varied between groups. ATS/IDSA microbiological criteria had a PPV of 89.8% in the high relevance group, while in the intermediate relevance group, the PPV of stricter and ATS/IDSA microbiological criteria was respectively 94.3% and 63.4%.

CONCLUSIONS

Microbiological criteria are useful in detecting NTM-PD, allowing laboratory-based monitoring. Stricter criteria should be used for species of low clinical relevance, and less stringent criteria for species of high relevance in the local setting.

Passive smoking and respiratory allergies in adolescents

OBJECTIVE

The aim of our study was to investigate impact of active and passive smoking on total and specific serum IgE levels and on incidence of developing allergic diseases (i.e. asthma, rhinitis) in a group of Croatian adolescents.

METHODS

Our study consisted of random sample of one hundred fifty-five (155) voluntary pupils (80 males and 75 females), with mean age of 16.72 +/- 1.25 years, from one high school in the city of Varazdin (north-west part of Croatia). Their smoking habits were examined by interview administered by a single trained survey worker while diagnosis of allergic disease (i.e. asthma and allergic rhinits) had to be previously confirmed by physician. Total and specific serum IgE levels were determined using enzyme-linked immunosorbent assay (ELISA) method in Central Laboratory of Clinic for lung diseases Jordanovac, Zagreb (Croatia).

RESULTS

Statistically significant higher prevalence of allergic diseases was found in the group of passive smokers as opposed to nonsmokers (chi2=9.29, p=0.002) as well as in active smokers compared to nonsmokers (chi2=4.45, p=0.034). Also, total IgE (IU/ml) was significantly higher in passive smokers when compared to non-smokers (t=13.039, p<0.01), and in passive smokers as opposed to active smokers as well (t=4.960, p<0.01), while difference in its level between active smokers and non-smokers was not statistically significant. The level of specific IgE to Dermatophagoides pteronyssinus between active smokers, passive smokers and non-smokers resulted to be not statistically significant.

CONCLUSIONS

Results of the study indicate that clinical manifestations of allergic diseases are more frequent in smokers (both active and passive) than in nonsmokers. Our investigation leads us to a presumption of a possibly more harmful effect of passive than active smoking in the adolescent high school population. Statistically highest IgE level in passive smokers as opposed to non-smokers or smokers could be attributed to longer duration of exposure to tobacco smoke in passive smokers and tobacco's potential cumulative effect on allergic senzitisa-tion, although investigations with more precised and detailed mesures including higher number of participants are warranted.