Andréa Gobetti Vieira Coelho

Características da tuberculose pulmonar em área hiperendêmica: município de Santos (SP)

OBJECTIVE To characterize the profile of patients with pulmonary tuberculosis (PTB) in the city of Santos, Brazil, according to biological, environmental and institutional factors. METHODS Descriptive study, using the TB surveillance database, including patients with PTB, aged 15 years or older, residing in the city of Santos and whose treatment was initiated between 2000 and 2004. RESULTS We identified 2,176 cases, of which 481 presented a history of TB. Of those 481 patients, 29.3% were cured, and 70.7% abandoned treatment. In 61.6% of the cases, the diagnosis was confirmed by sputum smear microscopy, whereas it was confirmed based on clinical and radiological criteria in 33.8%; 69.0% were male; and 69.5% were between 20 and 49 years of age. There were 732 hospitalizations, and the mean length of hospital stay was 32 days (first hospitalization). The prevalence of alcoholism, diabetes and TB/HIV coinfection was, respectively, 11.7%, 8.2% and 16.2%. The prevalence of TB/HIV coinfection decreased from 20.7% to 12.9% during the study period. The treatment outcome was cure, abandonment, death from TB and death attributed to TB/HIV coinfection in 71.0%, 12.1%, 3.9% and 2.5%, respectively. The directly observed treatment, short-course (DOTS) was adopted in 63.4% of cases, and there were no significant differences between DOTS and the conventional treatment approach in terms of outcomes (p > 0.05). The mean annual incidence of PTB was 127.9/100,000 population (range: 72.8-272.92/100,000 population, varying by region). The mean annual mortality rate for PTB was 6.9/100,000 population. CONCLUSIONS In areas hyperendemic for TB, DOTS should be prioritized for groups at greater risk of treatment abandonment or death, and the investigation of TB contacts should be intensified.

Estudo descritivo da freqüência de micobactérias não tuberculosas na Baixada Santista (SP)

OBJECTIVE The present study aims at describing the frequency of nontuberculous mycobacteria (NTM) species identified through laboratory testing of samples collected from non-sterile sites (sputum), as well as its frequency in HIV-infected and non-HIV-infected individuals in the Baixada Santista region of the state of São Paulo, Brazil, in the period from 2000 to 2005. METHODS Retrospective analysis of sputum smear microscopy results and culture was conducted based on the records on file at the Instituto Adolfo Lutz-Santos, the regional tuberculosis laboratory. RESULTS We analyzed 194 NTM strains isolated from 125 individuals, of whom 73 (58.4%) were HIV-negative and 52 (41.6%) were HIV-positive. Thirteen different species were identified: Mycobacterium kansasii; M. avium complex; M. fortuitum; M. peregrinum; M. gordonae; M. terrae; M. nonchromogenicum; M. intracellulare; M. flavescens; M. bohemicum; M. chelonae; M. shimoidei; and M. lentiflavum. In 19.2% of the cases, the bacteriological diagnosis was confirmed by isolation of the same species in at least two consecutive samples. CONCLUSIONS Our results show the importance of including systematic identification of NTM in the laboratory routine, and that its integration into the clinical routine could improve the characterization of the disease, thereby informing the planning of effective control measures in specific populations, such as individuals presenting tuberculosis/HIV co-infection.

Avaliação do crescimento em cordas na identificação presuntiva do complexo Mycobacterium tuberculosis

OBJECTIVE: Virulent strains of the Mycobacterium tuberculosis complex, under certain appropriate conditions, grow as characteristic ropes, bundles or serpentine cords known as cord factor or growth in cords. The objective of the present study was to evaluate cord factor detection as a method of achieving presumptive identification of the M. tuberculosis complex, comparing it to conventional typing tests. METHODS: A total of 743 strains were analyzed from January of 2002 to December of 2005 in the Mycobacteria Sector of the Adolfo Lutz Institute, located in the city of Santos, Brazil. Samples were obtained from clinical specimens collected from patients with respiratory symptoms treated at basic health clinics in the greater metropolitan area of Santos. Ziehl-Neelsen-stained smears were prepared, 301 (40.5%) in MB/BacT broth and 442 (59.5%) on solid media, either Lowenstein-Jensen or Ogawa-Kudoh. RESULTS: The sensitivity, specificity, positive predictive value and negative predictive value obtained during the performance comparison of the two methods (cord factor detection and conventional typing) using both isolation media were, respectively, 98.5, 88, 97 and 93%. The method was more sensitive on solid medium (100%), and the difference in sensitivity between the two media types was only 2.7%. CONCLUSIONS: Taking into consideration the results obtained, we conclude that, in laboratories with a high incidence of M. tuberculosis complex isolation and limited economic resources, cord factor detection is a fast and valid criterion for identifying these mycobacteria using liquid or solid medium. It also enables subsequent conclusive identification tests, as well as additional sensitivity tests when necessary.

A study of multidrug-resistant tuberculosis in risk groups in the city of Santos, São Paulo, Brazil

Monitoring the extent of and trends in multidrug-resistant tuberculosis (MDR-TB) is a priority of the Brazilian National Tuberculosis Control Programme. The current study aimed to estimate the incidence of MDR-TB, describe the profile of TB drug resistance in risk groups and examine whether screening for MDR-TB adhered to the recommended guidelines. A descriptive study that examined diagnosed cases of pulmonary TB was conducted in the city of Santos, Brazil, between 2000-2004. Of the 2,176 pulmonary TB cases studied, 671 (30.8%) met the criteria for drug sensitivity testing and, of these cases, 31.7% (213/671) were tested. Among the tested cases, 9.4% were resistant to one anti-TB drug and 15% were MDR. MDR was observed in 11.6% of 86 new TB cases and 17.3% of 127 previously treated cases. The average annual incidence of MDR-TB was 1.9 per 100,000 inhabitants-years. The extent of known MDR-TB in the city of Santos is high, though likely to be underestimated. Our study therefore indicates an inadequate adherence to the guidelines for MDR-TB screening and suggests the necessity of alternative strategies of MDR-TB surveillance.

Estudo comparativo entre um sistema de sonda genética e métodos clássicos na identificação das micobactérias

OBJECTIVE The emergence of tuberculosis/HIV co-infection and the increase in the number of cases of infection with nontuberculous mycobacteria (NTM) require rapid laboratory test results in the isolation and identification of mycobacteria. The objective of this study was to evaluate the identification of mycobacteria by means of gene probes in comparison with that obtained using classical biochemical methods. METHODS Between 2002 and 2004, 178 mycobacterial cultures, all testing positive for acid-fast bacilli, were analyzed. Samples were obtained from clinical specimens of patients with respiratory symptoms or with clinical suspicion of pulmonary tuberculosis/mycobacteriosis who were treated in the greater metropolitan area of Santos. RESULTS The gene probe identified 137 samples (77%) as Mycobacterium tuberculosis complex and 41 (23%) as NTM. Discordant results between the methods (3%) were obtained only in the year of implementation (2002). When comparing the methods, the sensitivity, specificity, positive predictive value and negative predictive value of the gene probe method were 98%, 93%, 98% and 93%, respectively. CONCLUSIONS Despite the cost, the identification of mycobacteria using the molecular technique is faster: maximum 3 h vs. 28-30 days for classical methods. The use of gene probes is a validated molecular technique. It is fast, easy to use and readily available on the market. It has high specificity and sensitivity, which justifies its implementation and routine use in referral laboratories, since it facilitates the diagnosis providing agile clinical interventions.

Laboratory identification of mycobacteria in respiratory samples from HIV-positive patients suspected of tuberculosis.

The records (2000 to 2004) of the Microbiology Laboratory of the Adolfo Lutz Institute in Santos, Brazil, were retrospectively analyzed regarding patients infected with the human immunodeficiency virus (HIV) and suspected of pulmonary tuberculosis. 1,321 samples for diagnosis purposes were selected, corresponding to 880 suspected tuberculosis cases in 693 patients. There were 134 smear-positive samples and mycobacteria growth occurred in 188 cultures, corresponding to 161 confirmed cases. Mycobacterium tuberculosis was identified in 126 (78.3%) and non-tuberculous mycobacteria in 39 (24.2%). In four cases, both Mycobacterium tuberculosis and non-tuberculous mycobacteria were simultaneously recovered from different samples. The profile of sensitivity to anti-tuberculosis drugs revealed 18 (14.3%) cases of resistance to at least one drug. These results reinforce the need to carrying out the complete laboratorial routine (sputum smear microscopy, culture and susceptibility to antituberculous drugs) for respiratory samples from human immunodeficiency virus-positive patients with suspected tuberculosis in order to direct appropriate therapy.

Epidemiological and laboratorial profile of patients with isolation of nontuberculous mycobacteria

Background: An increase in NTM diseases in the international scenario has been observed in recent years. Aims: To analyze the epidemiological and laboratory profiles of patients with isolation of nontuberculous mycobacteria (NTM) over one decade. A retrospective analysis of records of a mycobacterial reference laboratory found 135 cases with isolation of NTM. Methods: Clinical and epidemiological data were collected from the records of government health clinics and from the State notification system (TBWEB). The cases were geocoded by location based on the street address in the Mercator Transverse Universal projection, Datum SAD/69 and MapInfo software. Results: Most patients were male (66.7%), older than 50 years (40%) and had only completed elementary schooling (38.5%). Associated health problems were found in 71.8% of the subjects, with 43.7% being HIV positive and 25.9% having had tuberculosis in the past. Hospitals were the most able institutions to diagnose cases (45.2%). Sputum was the most common material tested (63.0%) with the bacilloscopy being positive in 33.3% of cases. The most common mycobacteria species in the region were Mycobacterium avium and M. abscessus/M. massiliense/M. bolletii. When the regional reference municipality was analyzed, M. avium and M. fortuitum were the most common species isolated in the urban area. Conclusions: In the study region, mycobacteriosis most affected adult males with low schooling. Most patients presented comorbidities in particular co-infection with the HIV virus. M. avium is the most prevalent species in the region with the M. abscessus/M. massiliense/M. bolletii species being the main cause of nosocomial infections.