The latest case of Rabies infection highlights the importance of prompt diagnosis and the limits of post-exposure prophylaxis (PEP). Researchers from the Virginia Department of Health and the Centers for Disease Control and Prevention (CDC) write in Morbidity and Mortality Weekly Report.

Lead author Julia Murphy that rabies should be considered in differential diagnosis of patients with signs or symptoms of encephalitis or myelitis, including autonomic instability, dysphagia, hydrophobia, paresis, and paresthesia, particularly if a nonspecific prodrome preceded the onset of these signs by 3 to 4 days.

"Progressive worsening of neurologic signs is characteristic of rabies and should be considered as a positive indicator for rabies. Patient history is important to identify a possible exposure to rabies and other encephalitides; however, rabies should never be ruled out based solely on the absence of definite exposure history," Murphy said.

Public Health Investigation

The late recognition of this rabies case in a patient who had been treated at 2 hospitals and lived in a communal household necessitated a public health investigation. Because the patient was assumed to have had communicable rabies 2 weeks before symptom onset, 13 other residents of the commune where she lived were examined, and 4 were advised to initiate PEP.

"The circumstances of this bite were related to the patient’s clinical condition," Murphy said. "It was reported that, as the patient's symptoms worsened and she experienced altered mental status, she bit one of the residents of the commune where she was living." 

A traveler should consider pre-exposure rabies vaccinations

Murphy said that this case highlights the importance of counseling those traveling or working in rabies-endemic countries about steps to take before possible rabies exposure, as well as after. 

"A traveler may also want to consider pre-exposure rabies vaccinations if a prolonged stay is planned or travel will be in remote areas where medical care might be difficult to obtain," Murphy said.

The authors recommend pretravel rabies vaccination for those involved in activities such as camping, hiking, biking, adventure travel, or caving as well as for those undertaking extended visits, such as the yoga tour. The rabies vaccine is highly effective when given prior to symptom onset, but survival is rare once the patient begins to exhibit signs of rabies.

"To date, fewer than 10 documented cases of human survival from clinical rabies have been reported, and only two did not have a history of pre- or post-exposure prophylaxis," Murphy said."If a vaccine is available locally," Murphy said, "it should be initiated regardless of the availability of RIG in that country. If a vaccine is not available, travelers may need to be medically evacuated." 

"Local and state health officials, working in collaboration with the CDC, can offer guidance, clinical consultation and diagnostic support," Murphy continued. "Clinicians who are unsure about reporting procedures in their jurisdictions are encouraged to contact their local health departments. Another great resource for zoonotic disease consultation is a state health department's State Public Health Veterinarian."