January 14, 2023
2 min read
Human rabies breakthrough infections are rare. However, researchers found that when they occur, they can be attributed to deviations from core practices or errors in administration of vaccination or rabies immunoglobulin.
“As CDC was collaborating with the Advisory Committee on Immunization Practices workgroup on updating vaccination recommendation for rabies, we were reviewing the frequency and characteristics of rabies infection after receiving post-exposure prophylaxis (ie, wound cleansing and rabies vaccination),” Erin R. Whitehouse, PhD, MPH, RN, health scientist in the HIV Care & Treatment Branch of CDC’s Division of Global HIV & TB, told Healio.
“In searching the literature, we realized that although there were some published case series, there was no existing systematic review of rabies cases following vaccination,” she said.
Because of this, Whitehouse and colleagues decided to conduct a systematic review to understand the characteristics of people who developed rabies after receiving at least one dose of post-exposure prophylaxis. According to the study, the researchers included 52 articles published between Jan. 1, 1980, and June 1, 2022, which included a total of 122 breakthrough infections.
Of the 122 breakthrough infections, 86 had available data showing a median time from exposure to symptom onset of 20 days (interquartile range = 16-24). Additionally, 115 had data on post-exposure prophylaxis (PEP) use that showed 89 (77%) had received PEP within 2 days of an exposure. Of the 116 patients with data on wound severity available, severe wounds — defined as wounds involving multiple wound sites or bites to the head, face or neck — were common, having been reported in 69% of participants with the available data.
The study also showed that “deviations from core practices” were reported in more than half of cases (56%), whereas other possible causes for breakthrough infections included errors in the administration of rabies immunoglobulin, such as delivery to the wrong site, the wound being sutured before immunoglobulin was administered or not all wounds being penetrated; errors in vaccine administration, such as not completing the vaccine series or receiving the wrong regimen; delays in seeking health care; and comorbidities or immunosuppression.
Erin R. Whitehouse, PhD, MPH, RN
“Rabies infection after receiving post-exposure vaccination is rare given the number of people who receive post-exposure every year and reported failures. However, patients particularly with severe wounds should ensure that they do proper wound care (washing of the wound) and seek care quickly,” Whitehouse said. “While rabies immunoglobulin is a limited resource, it should be prioritized for severe wounds such as those found in this review.”
She added that there are opportunities to improve care provided in the community when a person has an animal bite and also at health care facilities.
“Surveillance for rabies infections, especially when post-exposure vaccination has been given, is critical to preventing further deaths from rabies,” Whitehouse concluded.