INT J TUBERC LUNG DIS 14(1):5 © 2010 The Union
EDITORIAL
Hospital-based surveillance for DR-TB: necessary but not sufficient IN THIS MONTH’S Journal, Brito and colleagues describe a survey quantifying drug-resistant tuberculosis (DR-TB) in six hospitals that together care for approximately half of the TB cases in Rio de Janeiro State during a one-year period.1 Their study is to be commended for contributing to the awareness and understanding of DR-TB in Brazil. In Brazil, which ranks fourteenth in the list of high-burden countries for TB, there were an estimated 1019 multidrugresistant tuberculosis (MDR-TB) cases among the estimated 70 143 new pulmonary TB cases reported countrywide in 2007.2 Hospitals play an important role in case finding, early detection, reduced transmission, and entry into appropriate care for persons with MDR-TB. The authors note the importance of careful monitoring for anti-tuberculosis drug resistance.1 The World Health Organization (WHO) recommends that drug resistance surveys be performed regularly in high-burden countries, not only to determine the level of DR-TB, but also to strengthen laboratory capacity.3 In the context of monitoring for drug resistance; however, this paper raises other important issues: 1) universal availability of drug susceptibility testing (DST), needed for rapid and accurate diagnosis of drug resistance, is often lacking in high-burden countries; 2) laboratory quality assurance systems, both internal and external, are needed to maintain proficiency and ensure correct diagnoses; and 3) an accurate history of previous TB treatment (especially rifamycins) is important and necessary. Of note, the WHO also recommends that all persons with TB with a history of previous TB treatment undergo sputum culture and DST, a policy that was well followed in this study. The authors note that inadequate infection control measures were implemented in the study hospitals. Infection control measures are needed if nosocomial DR-TB is to be controlled.4 The WHO recommends consideration of infection control measures when constructing or renovating buildings where TB patients are cared for, and also that a national infection control plan be developed. One issue not actively discussed in this paper is that health care workers (HCWs) must also be protected from DR-TB. HCWs have an increased risk of TB and latent tuberculosis infection (LTBI) compared to the general population, and their level of risk is associated with age and length of employment in the health care industry.5 Furthermore, the risk of DR-TB transmission is not limited to the hospital, but is present in other settings such as congregate living facilities, prisons, and out-patient treatment centers. The authors’ findings, although important, do not prove that nosocomial TB transmission occurred;
transmission may also have occurred in the community or in other out-patient treatment settings. To determine whether nosocomial transmission occurred, the following steps should be taken: 1) an epidemiologic investigation should be performed to evaluate contacts of known cases for LTBI or TB; 2) TB genotyping should be undertaken to augment the epidemiologic investigation and confirm transmission patterns; 3) infection control practices in the hospital setting should be evaluated; and 4) whether ineffective treatment regimens led to delay in diagnosis and subsequent community transmission should be evaluated. These are essential next steps to develop effective measures to prevent the development and transmission of MDR-TB. In conclusion, a multi-pronged approach is needed to monitor the prevalence of DR-TB in communities, and to prevent nosocomial transmission of DR-TB. Periodic drug resistance surveys and international laboratory quality assurance standards should be implemented to monitor the presence of DR-TB. A focus on infection control practices in both in- and outpatient health facility settings, and prevention of TB transmission to HCWs, are needed to prevent nosocomial spread of DR-TB. Suzanne F. Beavers, MD* Timothy H. Holtz, MD, MPH† Denise O. Garrett, MD, MS* *Epidemiology Team, Surveillance, Epidemiology, and Outbreak Investigations Branch † Program Strengthening/Epidemiology International Research and Programs Branch Division of Tuberculosis Elimination Centers for Disease Control and Prevention Atlanta, Georgia, USA e-mail:
[email protected] disclaimer
The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the US Centers for Disease Control and Prevention.
References 1 Brito R C, Mello F C Q, Andrade M K, et al. Drug-resistant tuberculosis in six hospitals of Rio de Janeiro, Brazil. Int J Tuberc Lung Dis 2010; 14: 24–33. 2 World Health Organization. Global tuberculosis control 2009 —epidemiology, strategy, financing. WHO/HTM/TB/2009/411. Geneva, Switzerland: WHO, 2009. 3 World Health Organization. Guidelines for surveillance of drug resistance in tuberculosis. WHO/HTM/TB/2009.422. Geneva, Switzerland: WHO, 2009. 4 World Health Organization. WHO policy on TB infection control in health-care facilities, congregate settings, and households. WHO/HTM/TB/2009.419. Geneva, Switzerland: WHO, 2009. 5 Joshi R, Reingold A L, Menzies D, Pai M. Tuberculosis among health-care workers in low- and middle-income countries: a systematic review. PLoS Med 2006; 3: 2376–2391.
