The prevalence of latent tuberculosis (TB) infection (LTBI) and the incidence of active tuberculosis in healthcare workers (HCWs) in a Portuguese hospital were examined.This cross-sectional study comprises 4,735 hospital workers screened between May 2005 and September 2008. Tuberculin skin test (TST) and interferon-c release assay (IGRA) were used simultaneously in 1,219 HCWs (25.7%). Radiographs were taken in symptomatic HCWs or in testpositive HCWs. The tests were repeated annually or bi-annually depending on risk assessment.IGRA was positive in 32.6% and TST in 74.2% of the HCWs. Years spent in healthcare were a risk factor for a positive IGRA, but not for a positive TST. Repeated bacillus Calmette-Guérin vaccination increased the probability of TST+/IGRA-discordance (35.4% versus 54.4%, respectively). In those tested three times with TST during the study period (n559), the mean diameter of TST increased from 5 to 7 to 10 mm. Within 3 yrs, 31 HCWs were diagnosed with active TB (annual incidence rate 191 out of 100,000 people). In eight HCWs with active TB, TST and IGRA were performed at the time of diagnosis and each test was positive.TB burden in HCWs in Portugal is high. With IGRA, the number of radiographs needed to exclude active TB could have been reduced by about half without missing a case of active TB. Therefore IGRA should be introduced into TB screening programmes.

We investigated the levels of mite allergens (Der p 1, Der f 1, Der 2, and Lep d 1) in dust samples from the homes of 59 patients with asthma, 36 sensitized to house‐dust mites (HDM) and 23 to grass pollen (controls), living in Porto, northern Portugal. The relationship between exposure and sensitization to HDM and the influence of housing conditions on mite‐allergen levels were also evaluated. Der p 1 (median 9.2 μg/g) and Der 2 (4.6 μg/g) were the main allergens, while Der f 1 and Lep d 1 levels were always <1 μg/g dust and undetectable in 11% and 47% of samples, respectively. All HDM‐sensitized asthmatics were exposed to Der p 1 levels >2 μg/g and their homes contained significantly higher levels of Der p 1 (median 12.5 vs 6.4 μg/g; P=0.008) and Der 2 (6.2 vs 3.0 μg/g; f=0.004) when compared to the control group. A significant correlation was observed between the exposure to Der p 1 and the wheal area at skin testing with the Dermatophagoides pteronyssinus (Dp) extract (P=0.01) as well as with serum specific IgE levels to Dp (P=0.03). Patients with higher levels of serum specific IgE (≥17.5 HRU/ml) were also more frequently exposed to Der p 1 levels ≥10 μg/g (P=0.002). Old homes, presence of carpets, and signs of dampness were conditions associated with significantly higher levels of mite allergens. In conclusion, we found high levels of Der p 1 and Der 2 particularly in the homes of HDM‐sensitized patients and we confirm the relationship between exposure and sensitization to HDM, assessed by both in vivo and in vitro methods. In addition to a favorable outdoor climate, we found in our region housing conditions propitious to mite growth, suggesting that specific geographic characteristics must also be taken into account for the correct planning of mite‐avoidance measures.

Objective: to analyze component resolved diagnosis to Dermatophagoides pteronyssinus (Der p) in patients with respiratory allergy and its relationship with clinical severity in different geographical areas. Methods: 217patients (mean age 25.85±12.7 years; 51.16% females) were included, selected from 13 centers in Portugal (5 from North, n=65). All had allergic rhinitis, with or without asthma, and had positive skin prick tests to at least one dust mite.Specific IgE (sIgE) to Der p, Dermatophagoides farinae, Lepidoglyphus destructor, Der p1, Der p 2, Der p 10 and Der p 23 were determined by ImmunoCAP. Statistical analysis(Mann Whitney U test) compared patients with rhinitis vs rhinitis and asthma; mild vsmoderate-to-severe rhinitis; North vs South. Results: Prevalence of sensitization was 98.2% to Der p, and 72.4%, 89.4%, 9.7% and 77% to Der p 1, Der p 2, Der p 10 and Der p 23, respectively. Corresponding median sIgE levelswere 8.56, 17.7, 0.01 and 3.95 kU A /L. sIgE to all allergens was higher in patients with moderate-to-severe rhinitis and rhinitis with asthma but not statistically significant (NSS). sIgE to Der p 2 was significantly higher in the South when compared with the North (p=0.0496). Conclusions: sensitization to Der p is the most common in Portugal. Der p 2 had the highest prevalence and median sIgE levels. All sIgE to molecular components were higher in more symptomatic patients (NSS). sIgE to Der p 2 was higher in the South, which may be related to the warmer temperature and/or the larger sample size.

SCIT is a safe treatment when administered by trained staff. The WAO 2010 classification might be useful for retrospectively classifying the severity of reactions, although its usefulness in treatment decision needs further research.

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