A poster presented at IDWeek was a systematic review of 35 studies that found rare transmission of viral hemorrhagic fever to health care personnel in high-income countries and highlighted the need for standardized exposure definitions to guide response.
A systematic review presented as a poster at IDWeek in Washington, DC, held from October 21 to 24, found that transmission of viral hemorrhagic fevers to health care personnel in high-income countries was rare. Across 35 studies, presenting author Loukas Kakoullis, MD, PhD, MPH, Infectious Disease Fellow at Massachusetts General Hospital & Brigham and Women's Hospital in Boston, Massachusetts, and his fellow researchers reported 1,607 health care personnel exposures and 37 infections, an infection proportion of 2.3%. Among laboratory personnel, 296 exposures were reported, with no infections.
The poster, “Healthcare-Associated High-Consequence Viral Hemorrhagic Fever Exposure Events and Outcomes in High-Income Countries: A Systematic Review,” examined occupational exposures and associated infection outcomes. Alongside its findings on transmission, the review identified a need for more consistent descriptions of exposure events to support risk assessment and response.
“Standardized reporting of exposure definitions in the literature is needed to guide risk stratification and response,” the researchers stated.
Examining Exposures Before Disease Recognition
The researchers described viral hemorrhagic fevers as a risk to health care personnel. Delayed recognition can contribute to exposures, as can failure to isolate patients and inadequate use of personal protective equipment (PPE). The review sought to characterize these exposures in high-income countries and determine the associated infection outcomes.
Following PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines, the team searched MEDLINE through PubMed, Web of Science, and Embase. Eligible cases involved viral hemorrhagic fever diagnosed after admission that prompted an investigation. The researchers used the World Bank classification to identify high-income countries. Their outcomes included exposures among health care and laboratory personnel, with attention to exposure types, control measures, and subsequent infections.
The search identified 7,719 records from databases or registers and 4 references from other sources. After duplicates were removed, 5,890 records remained for screening. The final review included 35 studies.
The median exposure time before disease recognition and implementation of viral hemorrhagic fever precautions was 3 days. Source origins included Africa in 15 reports and Asia in 10. Europe accounted for 5, South America for 4, and North America for 1. Reporting locations differed, with 17 reports from Europe, 9 from North America, 8 from Asia, and 1 from South America.
Exposure Circumstances Varied
Lassa virus was the most frequently reported virus, appearing in 8 studies. Crimean-Congo hemorrhagic fever virus appeared in 7. Severe fever with thrombocytopenia syndrome virus and Ebola virus each appeared in 6 cases, while Andes virus appeared in 4 cases. Marburg virus appeared in 2, and Hantaan virus and Sabiá virus each appeared in 1.
Direct contact with body fluids was reported in 80% of studies, making it the most frequently documented exposure category. Physical contact without body fluids appeared in 69%. These percentages describe the proportion of studies reporting each circumstance, rather than the proportion of individual personnel exposed.
PPE use was another prominent finding. Some, but not all, required PPE was used in 49% of studies, while 37% reported no PPE use. Handling laboratory specimens appeared in 43% of studies, and indirect contact with body fluids appeared in 31%.
Intubation, whether performed by the exposed person or occurring in their presence, was reported in 23% of studies. Handling contaminated waste also appeared in 23%. Mucosal exposure was reported in 20%, and performing cardiopulmonary resuscitation appeared in 17%. Surgery was reported in 6%, while sharps injuries appeared in 3%.
Contact Tracing Was the Most Frequently Reported Intervention
Contact tracing was documented in 89% of studies. Monitoring exposed contacts appeared in 83%, and testing contacts appeared in 80%. Isolation wards were used in 57% of studies, while PPE use after case identification was reported in 46%.
Specialized sample management was reported in 34% of studies. Specialized waste management was reported in 23%, and quarantine of exposed contacts appeared in 20%. Staff cohorting was reported in 6%. For exposure management, ribavirin prophylaxis was reported in 20% of studies, while ribavirin treatment was reported in 6%.
The poster’s central finding was clear: “Transmission of viral hemorrhagic fevers to health care personnel in high-income settings is rare.” However, its call for standardized exposure definitions remains an important part of that conclusion. More consistent reporting would help guide the categorization of exposures and teams' responses, while preserving the distinctions between exposure circumstances and resulting infections.
