A newly released report reveals that over a year ago a man was bitten by a vampire bat on July 15, 2010 at home in Mexico. Instead of worrying too much about it, he opted to cross the United States border seeking work in Louisiana. One day later after securing a job, he began feeling extensive pain in his shoulder, numbness and a lazy left eye. He eventually died on August 21 of the same year.
The nineteen year old migrant farm worker from Mexico became the first person in the United States to ever die from a vampire bat bite, according to the Centers for Disease Control and Prevention (CDC).
Health officials pointed out that the man’s roughly two-week incubation period was far shorter than the median of 85 days reported in other human rabies bite cases in the United States.
Another learning from this incident is that vampire bats may be migrating north. Vampire bats have traditionally only been found in Latin America. The CDC suggested that the bats might now be moving north because of changes in the climate.
The report states:
“Expansion of vampire bats into the United States likely would lead to increased bat exposures to both humans and animals (including domestic livestock and wildlife species) and substantially alter rabies virus dynamics and ecology in the southern United States.”
The patient’s physical examination at the referral hospital revealed hyperesthesia of the left shoulder, weakness of the left hand, generalized areflexia, and drooping of the left upper eyelid. A lumbar puncture produced cerebrospinal fluid (CSF) with a mildly elevated white blood cell count of 8 cells/mm3 (normal: 0–5 cells/mm3) with 67% lymphocytes and 12% neutrophils, a normal glucose, and no organisms on staining. The patient was admitted to the intensive-care unit for suspected Miller-Fisher variant of acute inflammatory demyelinating polyneuropathy (also referred to as Guillain-Barré syndrome), with viral encephalitis and early meningitis among the alternative diagnoses considered.
The next day, the patient developed a fever of 101.1°F (38.4°C) and signs of respiratory distress that prompted elective intubation. Computerized tomography and magnetic resonance imaging of the head revealed only a developing sinusitis. During the next several days, the patient became gradually less responsive to external stimuli, developed fixed and dilated pupils, and began having episodes of bradycardia and hypothermia.
Further evaluation included a repeat lumbar puncture revealing an elevation of the white blood cell count to 87 cells/mm3 with 97% lymphocytes and an elevated protein of 233 mg/dL (normal: 15–45 mg/dL). An electroencephalogram was consistent with encephalitis. Bacterial, viral, and fungal cultures of blood and CSF were negative.
Although no history of animal exposures was known at that time, a diagnosis of rabies was suspected based on the clinical history and available data. The Louisiana Office of Public Health was informed of the potential case of rabies, and infection control precautions were instituted on August 13, the 11th hospital day.
On August 20, rabies virus specific immunoglobulin G and immunoglobulin M detected in the patient’s CSF and serum confirmed the diagnosis of rabies. After discussion with the family about the patient’s prognosis and a subsequent electroencephalogram showing severe cortical impairment, the patient was extubated on August 21 in accordance with the family’s wishes and died shortly thereafter.
Written by Sy Kraft