TB - 1
VOLUME 20, NUMBER 1 , National medical Journal of india Protecting healthcare workers from tuberculosis in the era of extensively drugresistant tuberculosis .
MADHUKAR PAI Department of Epidemiology Epidemiology,, Biostatistics andOccupational Health McGill University Montreal Quebec Canada madhukar [email protected] [email protected]
What is the situation in India, a country that has more TB patients than any other country, and accounts for one-fifth of the world’s incident TB cases? A recent review of several Indian studies showed that nosocomial transmission of TB is an important but poorly documented problem in India. 7 The prevalence of LTBI and annual risk of TB infection appears to be high (about 5% per year, much higher than the national average of about 1.5% 8) even among young HCWs and medical and nursing trainees. 9,10 For example, based on available data, in a hypothetical Indian hospital with 1000 HCWs, about 500 (50%) will have LTBI, and about 25 (5%) of the uninfected HCWs will be newly infected every year.7 The rate of active disease appears to be exceedingly high in subgroups such as interns, residents and nurses.11 The incidence rates of TB disease and infection are higher than the national averages, suggesting an increased risk of acquiring TB in the hospital setting.7 For example, the estimated incidence of TB among medical residents was 10-fold higher than the incidence for the country.11 Interestingly, most Indian studies have shown that the predominant clinical presentation of TB in HCWs is extrapulmonary (mostly pleural). 11-13 This may indicate progression to disease from newly acquired primary infection rather than reactivation of latent TB. Lastly, although limited, there is some evidence from molecular epidemiological studies that nosocomial transmission of TB among hospitalized patients may be occurring in urban hospitals. 14 In summary, there is growing evidence that TB is an important occupational problem among HCWs in poor countries. The available evidence clearly underscores the need to design and implement simple, effective and affordable TB infection control programmes in healthcare facilities in developing countries. The need for implementing interventions is made more urgent because of a new threat identified recently—extensively drug-resistant tuberculosis (XDR-TB).15 XDR-TB is defined as TB resistant to at least isoniazid and rifampicin (which is the definition of MDR-TB) in addition to any fluoroquinolones, and to at least one of three injectable second-line anti-TB drugs (i.e. kanamycin, amikacin and capreomycin). 15 Because XDR-TB is resistant to several first- and second-line drugs, treatment options are severely limited, and mortality rates are extremely high. 15
Lung India. 2009 Apr-Jun; 26(2): 33–34. PMCID: PMC2860410 doi: 10.4103/0970-2113.48893
Tuberculosis transmission at healthcare facilities in India Ashutosh N. A Aggarwal ggarwal Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India. E-mail: [email protected]
Copyright © Lung India
We recently published our experience regarding the risk and incidence of active tuberculosis among resident doctors at our institute.4 The study had two groups. The first included 538 resident doctors already working at our institute, of whom 470 were interviewed. The second included 235 resident doctors freshly admitted to the institute over a one-year period, of whom 231 were prospectively followed up. Tuberculosis was diagnosed based on history, radiology, laboratory workup, and response to treatment. In the first group, nine doctors had tuberculosis while working in hospital, amounting to 11.2 new cases per 1000 person-years of exposure. Six of them had extrapulmonary disease. Seven worked in medical and two in surgical specialties and none had any comorbidity or other risk factors. In the second group, four doctors (two junior and two senior residents) developed active tuberculosis in the first year of their work at our institute, amounting to an overall incidence of 17.3 per 1000. Three of them had extrapulmonary disease, and the fourth had sputum positive pulmonary disease. Again none had anydisease comorbidity other risk factors. Thesewith dataincidence suggestedfigures high rates of active amongorphysicians in training, much higher than those in general population. A notable point was that most had extrapulmonary disease (and were therefore diagnosed on clinical rather than microbiological criteria), and it is possible that they suffered from primary rather than reactivation disease. It was however not clear if infection was acquired during or before stay at our institute. Around the same time, a ten-year review of hospital records was published from Vellore.5 Data on 125 healthcare workers who received treatment for tuberculosis during 1992–2001 were collected. Incidence of pulmonary tuberculosis varied from 0.37–1.57 per 1000, and that of extrapulmonary
tuberculosis varied from 0.34–1.57 per 1000, in different years. Overall incidence of sputum positive disease was thus quite similar to general population, whereas that of extrapulmonary tuberculosis was higher than general population. The maximum cases were diagnosed among nursing staff and students. Certain groups of healthcare workers had higher incidence in certain years, suggesting focal outbreaks, although this could not be verified from this retrospective analysis. There is also some information on latent tuberculosis among healthcare workers. A cross-sectional prevalence study was conducted at Sevagram on 726 healthcare workers with no prior history of tuberculosis. 6 The cohort comprised mainly of medical students (31%), nursing students (17%), and nurses (22%). Both tuberculin skin testing and an ELISA-based gammainterferon release assay were used. Fifty percent healthcare workers were found latently infected (positive by either of the two tests). Nurses, nursing students, orderlies, and laboratory staff showed higher prevalence of infection, and advancing age and employment duration were identified as risk factors. However, these prevalence figures are likely to be an underestimate due to nonparticipation by the vast majority of senior physicians at the hospital. All these healthcare workers were kept under follow up and a repeat survey of 216 medical and nursing students of this cohort was conducted after a gap of 18 months.7 Both tuberculin skin testing and gamma-interferon release assay were again performed in an attempt to estimate annual risk of infection. Data from 147 valid follow-ups with both tests were reported. Eleven (7.5%) healthcare workers had conversion on one or both tests; this corresponds to annual risk of infection of approximately 5%. If average community based annual risk of infection in India is considered about 1.5%, the 3.5% excess risk among healthcare workers may be attributable to nosocomial exposure.
Nosocomial Tuberculosis Tuberculosis in India Madhukar Pai,*† Shriprakash Kalantri,† Ashutosh Nath Aggarwal,‡ Dick Menzies,§ and Henry M. Blumberg¶ Emerging Infectious Diseases • www.cdc.gov/eid www.cdc.gov/eid • Vol. 12, No. 9, September 2006
Journal of Hospital Infection Volume 57, Issue 4, 4, August 2004, Pages 339–342
Tuberculosis among healthcare workers in a tertiary-care hospital in South India K.G Gopinatha, S Siddiqueb, H Kirubakaranb, A Shanmugamc, E Mathaia, , , G.M Chandya The object of this study was to document the incidence of tuberculosis among HCWs in the Christia Chri stian n Medi Medical cal Coll College ege (CMC (CMC), ), Vello ellore, re, Indi Indiaa duri during ng a 10-y 10-year ear peri period od (Jan (January uary 199 1992– 2– December 2001). Data were collected from records maintained in the staff and students health services of CMC. A total of 125 cases were diagnosed during the period of study. The overall incidence of sputum positive cases was similar to that observed in the general population, during most years. However, it appears that focal outbreaks occur with transmission between HCWs. The chance of developing extra-pulmonary tuberculosis was higher in HCWs compared with the general population.
Indian Journal of Tuberculosis New Delhi, April 2009 No. 2 NOSOCOMIAL TUBERCULOSIS IN THE ERA OF DRUG RESISTANT TUBERCULOSIS [Indian J Tuberc 2009; 56:59-61] A recent review of several Indian studies showed that nosocomial transmission of TB is an importantt but poorly documented importan documented problem in India1. The prevalence of LTBI LTBI and annual risk of TB infection appears to be high (about 5% per year, much higher than the national average of about 1.5%) among young HCWs and medical and nursing trainees suggesting an increased risk for acquiring TB in the hospital setting. The rate of LTBI is 50% and active disease appears to be exceedingly high in sub-groups such as interns, residents and nurses7. The predominance of extra-pulmonary (mostly pleural) disease among healthcare workers8 may indicate progression to disease from newly acquired primary infection rather than reactivation of latent TB