Imported Human Rabies Cases

In the U.S., human rabies is rare, thanks mostly to the availability of rabies vaccination and the elimination of dog rabies. But in many other countries around the world, dog rabies is very common and people are at greater risk. When a person travels or immigrates from an area of higher risk (like Mexico) to an area of lower risk (like the United States), they may encounter obstacles in getting diagnosed correctly if they have rabies. A recent human rabies case from California demonstrates the challenges that can arise when attempting to administer care to a person from another country.

The patient returned to the home of an aunt. The next day, he collapsed, and when paramedics arrived, the patient was not breathing, unresponsive, and could not be resuscitated. After the boy’s death, the ED physician began to consider rabies as the cause of his illness for two primary reasons: he presented several rabies symptoms (hydrophobia, aggressive behavior, and depression) and came from a region of Mexico where dog rabies is very common. An investigation was initiated to confirm the physician’s suspicion. After interviewing family members, talking with Mexican health authorities, and conducting lab tests, much was learned:

• There were several stories about how he was exposed to rabies — one that implicated a dog bite and another a fox bite the patient had received approximately 3-4 months prior to leaving Mexico.
• The rabies virus variant responsible for the patient’s infection was characterized as a bat rabies virus variant which had not been previously identified in the U.S. or in Mexico.
• This case represented the first case of imported rabies in the United States not attributable to a dog rabies virus variant

What might this mean for rabies prevention and control between lower and higher risk countries? Well, a few things pop to mind as being critically important:

• Sharing information between countries about persons affected as well as variants of the virus can be helpful in identifying new variants of a disease and implementing control measures and prevention education in both countries
• Establishing collaborative efforts, especially along border regions, among entities that have a stake in human and animal health is key too. Having procedures for sharing cases of disease among people and animals can lead to faster identification of cases and outbreaks as well as to prevention and control measures.

For more information, please see the MMWR article from July 10, 2009

• Imported Human Rabies – California, 2008