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Published on: February 23, 2014
Nosocomial transmission of opportunistic infections
1San Francisco General Hospital, CA 94110, USA.
Abstract:
Immunocompromised patients are at high risk for opportunistic infections. Traditionally, these infections were thought to arise from endogenous reactivation of previously acquired latent infections, and nosocomial transmission therefore was deemed to be so unlikely that no special infection control interventions were needed to prevent transmission in healthcare settings. However, new data have challenged this view and suggest that some opportunistic pathogens are transmissible from one immunosuppressed patient to another. Epidemiological investigations, molecular genotyping, animal studies, and air-sampling experiments lend support to the hypothesis that reinfection with opportunistic pathogens does occur, that airborne transmission is possible, and that nosocomial spread is a plausible explanation for case clusters. Taken together, these observations support the view that some opportunistic infections are exogenous in origin and that additional epidemiological investigations are needed to define the true risk of nosocomial spread and need for isolation.
Insights
Opportunistic infections in immunocompromised patients may spread between individuals, challenging traditional views. New evidence suggests airborne transmission and nosocomial spread are plausible, necessitating further research into infection control.
Area of Science:
- Infectious Diseases
- Epidemiology
- Healthcare-Associated Infections
Background:
- Immunocompromised patients face high risks for opportunistic infections.
- Historically, these infections were attributed to endogenous reactivation, with low perceived risk of nosocomial transmission.
- Traditional infection control measures did not prioritize preventing transmission of these pathogens in healthcare settings.
Purpose of the Study:
- To challenge the traditional view of opportunistic infections arising solely from endogenous reactivation.
- To investigate the potential for nosocomial transmission of opportunistic pathogens among immunocompromised patients.
- To evaluate the plausibility of airborne transmission and exogenous reinfection.
Main Methods:
- Review of epidemiological data and case clusters.
- Molecular genotyping to trace pathogen origins.
- Animal studies to model transmission dynamics.
- Air-sampling experiments to assess airborne viability.
Main Results:
- Emerging data suggest opportunistic pathogens can be transmitted between immunosuppressed patients.
- Evidence supports the possibility of airborne transmission of opportunistic pathogens.
- Nosocomial spread is a plausible explanation for observed clusters of opportunistic infections.
Conclusions:
- Opportunistic infections may be exogenous in origin, acquired through patient-to-patient transmission.
- Airborne transmission is a potential route for the spread of opportunistic pathogens in healthcare settings.
- Further epidemiological studies are required to accurately define the risk of nosocomial spread and the need for specific isolation precautions.
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