Adapting and Evaluating a Rapid, Low-Cost Method to Enumerate Flies in the Household Setting.

Diarrhea is a leading cause of death among children under 5 years of age worldwide. Flies are important vectors of diarrheal pathogens in settings lacking networked sanitation services. There is no standardized method for measuring fly density in households; many methods are cumbersome and unvalidated. We adapted a rapid, low-cost fly enumeration technique previously developed for industrial settings, the Scudder fly grill, for field use in household settings. We evaluated its performance in comparison to a sticky tape fly trapping method at latrine and food preparation areas among households in rural Kenya. The grill method was more sensitive; it detected the presence of any flies at 80% (433/543) of sampling locations versus 64% (348/543) of locations by the sticky tape. We found poor concordance between the two methods, suggesting that standardizing protocols is important for comparison of fly densities between studies. Fly species identification was feasible with both methods; however, the sticky tape trap allowed for more nuanced identification. Both methods detected a greater presence of bottle flies near latrines compared with food preparation areas (P < 0.01). The grill method detected more flies at the food preparation area compared with near the latrine (P = 0.014) while the sticky tape method detected no difference. We recommend the Scudder grill as a sensitive fly enumeration tool that is rapid and low cost to implement.

Venturi atomizers as potential sources of patient cross-infection.

Venturi-principle atomizers, which rely on compressed air to aerosolize medications, are commonly used in clinical practice to apply topical anesthetics and vasoconstrictors to the mucous membranes of the nose and throat. Unfortunately, the mechanism by which these devices operate leads to aspiration of external contaminants back into the device at the end of the spray cycle. This "flaw" in design may make Venturi-principle atomizers unsafe for clinical practice because of the risk of patient cross-infection. This article reviews the mechanism of action of Venturi-principle atomizers, presents the scientific literature regarding their potential for cross-infection of patients, and discusses alternative device options.