Sunday, March 07, 2010

Abortive Rabies

Via ProMED-mail: the CDC reports on a rabies case from last year in which the victim was intermittently symptomatic ("severe frontal headache, photophobia, emesis, neck pain, dizziness, and paresthesia of face and forearms") for two and a half weeks before rabies vaccine and immune globulin were administered. She soon appeared to recover without intensive care.

This is the first reported case in which certain clinical and serologic findings indicate abortive human rabies and in which, despite an extensive medical investigation, no alternate etiology for the illness was determined. The patient's positive serologic results offer evidence of rabies virus infection; IFA and Western blot assays indicated the presence of antibodies capable of binding to rabies virus antigens before the patient received rabies PEP. Rabies virus can crossreact serologically with other members of the Lyssavirus genus, distributed in Australia, Eurasia, and Africa (5) or, theoretically, with as yet uncharacterized rhabdoviruses. However, this patient had no history of foreign travel and no evidence of infection with KCV, the only other rhabdovirus associated with bats in North America.
Certain other clinical and laboratory findings also support a diagnosis of abortive rabies in the patient described in this report. First, the onset of acute encephalopathy approximately 2 months after exposure to bats is compatible with documented incubation periods after rabies virus exposure. Second, central nervous system (CNS) findings (e.g., fever, photophobia, emesis, neck pain, dizziness, paresthesia, limitation of visual field, and altered behavior with agitation and combativeness) are compatible with clinical aspects of rabies. Although this patient did not have classic symptoms such as laryngeal spasms (manifested as hydrophobia) or autonomic instability, the lack of such symptoms has been documented in other rabies patients (1,2,6). Finally, despite an extensive medical workup, no alternate infectious etiology was identified for the patient's neurologic symptoms, increased intracranial pressure, and CSF pleocytosis.

I should note that, after her apparent recovery, the patient returned to the hospital two more times complaining of headaches, and afterwards went missing. ("The current clinical status of the patient or [sic] her boyfriend is unknown.") Judging from the reporting state, the patient was probably in the country illegally. PlagueBlog would not jump to the conclusion that she is still here, or still alive.