Nosocomial transmission and infection control aspects of parasitic and ectoparasitic diseases. Part III. Ectoparasites/summary and conclusions.

As a rule, both the standard of hygiene and sanitation prevalent in hospitals in the United States and the rarity of parasitic diseases compared to viral, bacterial, and fungal infections, reduce the hazard of nosocomial acquisition of parasites to relatively trivial levels. However, abetted by the resultant low index of suspicion on the part of clinical staff, certain parasitic microorganisms may at times cause significant morbidity and even mortality in both normal and immunocompromised patients, as summarized in this review. Also, the nosocomial acquisition of parasites may be somewhat underappreciated because the incubation period for clinical illness may be days to weeks and thus a hospital-acquired infection may not be recognized as such, particularly if the parasite is endemic locally. Parasitic diseases have been a much more significant problem in certain special facilities, such as custodial institutions for the mentally ill or retarded, where crowding, poor environmental sanitation, and low levels of personal hygiene have in the past allowed the rapid dissemination and endemic occurrence of a large variety of parasitic infections. It is likely that nosocomial transmission of parasites may be an even greater problem in some hospitals in the tropics, where strict hygienic standards are costly or otherwise more difficult to maintain, and where often an increased proportion of the patient population harbors one or more parasites. However, the exact magnitude of the problem in tropical hospitals is also more difficult to determine because nosocomial acquisition of a parasitic infection may not be distinguished easily versus exogenous infection or reactivation of latent infection.(ABSTRACT TRUNCATED AT 250 WORDS)