Tuberculosis notification from 1987 to 1999 for the public health area of the community of Valencia (Spain)

OBJECTIVE: Undernotification of tuberculosis (TB) is common worldwide but h as hardly been studied in Spain. The objective of this study was to determi ne how many cases of TB are reported in our health care area. MATERIAL AND METHOD: Between 1987 and 1999 we carried out a direct study of the incidence and reporting of TB cases in our area (106,632 inhabitants o n the census). Cases were taken from mandatory notification, pathology and bacteriology files and were then reviewed. RESULTS: Of the 410 TB cases diagnosed, 378 were residents of the area (ann ual incidence: 27/100,000 inhabitants), 223 of whom were reported (54%). Fo rty-eight patients were under 15 years of age. Sixty-seven percent of the p ediatric cases and 53% of the adult cases were reported (n.s.). Of the 78 c ases with HIV co-infection, only 32%,were reported, in contrast with 60% of MV-negative cases (p < 0.001). Of the 300 cases with pulmonary involvement , 56% were reported, versus 50% of those with exclusively extrapulmonary in volvement (n.s.). For the 149 with positive Ziehl-Neelsen stain, 61% were r eported, in contrast with 51% of those who were smear negative (ns.). Diagn osis was based on clinical signs in 65 cases (16%), 51% of which were repor ted, versus 55% of those in which diagnosis was based on bacteriology or hi stology consistent with TB (n.s.). Overall undernotification tended to decr ease during the study period (r = -0.73, p < 0.005). Undernotification also tended to decrease for patients with pulmonary involvement (r = -0.83, p < 0.0001) and for those with positive Ziehl-Neelsen staining of sputum (r = -0.79, p < 0.001). Likewise, undernotification also decreased for HIV negat ive patients (r = -0.74, p < 0.02) but not significantly so for HIV positiv e patients r = 0.44, n.s.). CONCLUSIONS: Direct quantification of cases revealed a significant degree o f undernotification. that is tending to decrease. Undernotification is grea test for HIV-positive patients and is not changing. No differences were see n for smear positive and smear negative patients, by pulmonary or extra-pul monary involvement, for clinical versus laboratory diagnosis, or for patien ts who were younger or older than 15 years of age. Reporting should be impr oved so that measures to decrease the incidence of TB can be taken.