Improving natural ventilation in hospital waiting and consulting rooms to reduce nosocomial tuberculosis transmission risk in a low resource setting.

Background: TB transmission in healthcare facilities is an important public health problem, especially in the often-overcrowded settings of HIV treatment scale-up. The problem is compounded by the emergence of drug resistant TB. Natural ventilation is a low-cost environmental control measure for TB infection control where climate permits that is suited to many different areas in healthcare facilities.

Simulation of risk of tuberculosis infection in healthcare workers in hospitals of an intermediate incidence country.

We simulated the frequency of tuberculosis infection in healthcare workers in order to classify the risk of TB transmission for nine hospitals in Medellín, Colombia. We used a risk assessment approach to estimate the average number of infections in three risk groups of a cohort of 1082 workers exposed to potentially infectious patients over 10- and 20-day periods. The risk level of the hospitals was classified according to TB prevalence: two of the hospitals were ranked as being of very high priority, six as high priority and one as low priority.

Evaluation of bleach-sedimentation for sterilising and concentrating Mycobacterium tuberculosis in sputum specimens.

Background: Bleach-sedimentation may improve microscopy for diagnosing tuberculosis by sterilising sputum and concentrating Mycobacterium tuberculosis. We studied gravity bleach-sedimentation effects on safety, sensitivity, speed and reliability of smear-microscopy.

Methods: This blinded, controlled study used sputum specimens (n = 72) from tuberculosis patients.

Tuberculosis in household contacts of multidrug-resistant tuberculosis patients.

Setting: The burden of tuberculosis (TB) disease among household contacts of multidrug-resistant TB (MDR-TB) patients is poorly understood and might represent a target for transmission-interrupting interventions.

Design: This retrospective cohort study, conducted in Lima, Peru, from June to September 2008, estimated the incidence of TB disease among household contacts of MDR-TB patients in 358 households.

Results: Of 2112 household contacts in 80 households (22% of households), 108 (5%) developed TB disease during the study, giving an incidence rate of 2360 per 100 000 contact follow-up years for each of the first 3 years after exposure.

Tuberculosis transmission risk and infection control in a hospital emergency department in Lima, Peru.

Background: Overcrowded emergency departments (EDs) are used by undiagnosed tuberculosis (TB) patients. TB infection control measures are seldom prioritized, making EDs potential foci of unrecognised nosocomial transmission.

Objective: To quantify TB infection risk among health care workers in an ED in a high TB-burden setting, Lima, Peru, and to evaluate TB infection control measures.