Risk factors for tuberculosis among health care workers in South India: a nested case-control study

OBJECTIVE

The epidemiology of tuberculosis (TB) among health care workers (HCWs) in India remains under-researched. This study is a nested case-control design assessing the risk factors for acquiring TB among HCWs in India.

STUDY DESIGN AND SETTINGS

It is a nested case-control study conducted at a tertiary teaching hospital in India. Cases (n = 101) were HCWs with active TB. Controls (n = 101) were HCWs who did not have TB, randomly selected from the 6,003 subjects employed at the facility. Cases and controls were compared with respect to clinical and demographic variables.

RESULTS

The cases and controls were of similar age. Logistic regression analysis showed that body mass index (BMI) <19 kg/m(2) (odds ratio [OR]: 2.96, 95% confidence interval [CI]: 1.49-5.87), having frequent contact with patients (OR: 2.83, 95% CI: 1.47-5.45) and being employed in medical wards (OR: 12.37, 95% CI: 1.38-110.17) or microbiology laboratories (OR: 5.65, 95% CI: 1.74-18.36) were independently associated with increased risk of acquiring TB.

CONCLUSION

HCWs with frequent patient contact and those with BMI <19 kg/m(2) were at high risk of acquiring active TB. Nosocomial transmission of TB was pronounced in locations, such as medical wards and microbiology laboratories. Surveillance of high-risk HCWs and appropriate infrastructure modifications may be important to prevent interpersonal TB transmission in health care facilities.

Acute acalculous cholecystitis: a rare complication of typhoid fever

Acute acalculous cholecystitis is a very rare complication of typhoid fever, and may be due to multi-drug resistant and virulent forms of Salmonella infection. It is particularly rare in adults. A 21-year-old woman, presenting with fever, vomiting, diarrhoea and abdominal pain, was found to have acute acalculous cholecystitis due to typhoid fever on basis of ultrasonographical findings and a positive Widal's test for Salmonella typhi. She was treated with antibiotics and made a full recovery.

Evaluation of serological tests for the diagnosis of tuberculosis

To evaluate the use of antibody detection kits in the diagnosis of pulmonary tuberculosis in an endemic area, serum samples from cases (sputum smear positive for AFB) and controls (healthy young adults) were collected and tested using five different kits. Sensitivity, specificity and predictive values were calculated using smear positivity as gold standard. Sensitivity of tests varied from 46% to 68% and the specificity from 68% to 100%. None of the kits evaluated can be used as a single screening test for tuberculosis. However kits with good specificity may be used in conjunction with conventional methods for diagnosis.

Should health care workers in the tropics be immunized against varicella?

In tropical regions, chickenpox affects both adults and children. Therefore, healthcare workers in the tropics are vulnerable to hospital-acquired varicella infection and they may transmit infection to susceptible hospitalized individuals. Although the varicella vaccine is safe and effective, its cost is a deterrent to its use in routine immunization programmes. In order to assess whether vaccination of susceptible healthcare workers to prevent hospital-acquired transmission may be justified, we have documented the frequency of varicella among healthcare workers in our hospital. There were 96 admissions for varicella during the 1993-1997 period; staff and student nurses accounted for 76%. The peak season of admission was from February to April. The attack rate in staff and student nurses was 0.78 and 1.54 per 100 person-years, respectively. While community outbreaks of varicella occur in this region once in 4-5 years, hospital outbreaks of varicella occurred every year. This poses the risk of transmission to hospitalized patients, with serious consequences among immunocompromized individuals. Therefore, we recommend systematic selective vaccination of susceptible healthcare workers to break this cycle of annual varicella outbreaks among hospital personnel.

Profile of hospital admissions following acute poisoning--experiences from a major teaching hospital in south India

This study was conducted to determine the incidence of hospital admissions following acute poisoning, nature of agents involved and change in pattern of poisoning over a 5-year period. Data from hospital records of all admissions to emergency department following acute poisoning collected prospectively were analysed for the period January 1993 to January 1998. A steady increase in deliberate poisoning using pesticides, particularly among young adults, was noted. Kerosene (paraffin) was the commonest poison in children and plant poisons were also common. There were 52 deaths (3.3%) among the 1584 admissions. The majority of deaths were due to pesticides. Poisoning and mortality followed ingestion of readily-available and commonly used agents. Measures to increase public education, counselling and awareness could prevent a number of these admissions.