An epidemic of pneumococcal disease in an overcrowded, inadequately ventilated jail.

States that correctional facilities in the US can be susceptible to outbreaks of respiratory infections due to overpopulation. Risk factors for pneumococcal disease were assessed in a case-control and a cohort study. The jail studied had a capacity of 3500 inmates but housed 6700. Median living area was 34 ft2. Fewer cases of disease were identified among inmates with 80 ft2 per person or more. CO2 levels were over the acceptable level.

Effectiveness of in-room air filtration and dilution ventilation for tuberculosis infection control.

The effectiveness of in-room air filtration systems was experimentally evaluated, specifically portable air filters (PAFs) and ceiling-mounted air filters, in conjunction with dilution ventilation, in order to control TB exposure in high-risk environments. A test aerosol was continuously generated and released into a full-sized room. Time-averaged airborne particle concentrations were measured at several points. The effectiveness was determined by a comparison of particle concentrations with and without device operation. Increasing rate of air flow did not always increase effectiveness.

The relative efficacy of respirators and room ventilation in preventing occupational tuberculosis.

The study described attempted to assess the relative efficacy of personal respiratory protection when infectious aerosol concentration increases or room ventilation rates decrease. A variable for respirator leakage was added to the Wells-Riley mathematical model of airborne transmission of disease. States that infection risk decreases exponentially with increasing room ventilation or personal respiratory protection. As room ventilation rates increase, or concentrations of infectious aerosols decrease, the relative efficacy of personal respiratory protection decreases.