Usually the death of a crow does not merit a front page news story. But the crow found down July 12 in Dixon, in Solano County, succumbed to West Nile virus and this fact garnered the poor bird much attention. With summer upon us, it is once again West Nile virus season. Clinicians throughout PHC’s network need to have their antennas raised to watch for this problem.

We do not intend this post to be a comprehensive review of the diagnosis and treatment of West Nile Virus. Instead, we just want to refresh your memory on a few issues:

• West Nile viral infections are spread to humans by mosquito bites.
• Though West Nile viral infections in humans are often asymptomatic, they can at times make people very ill.
• The principal manifestations of West Nile infections in humans are fever, malaise, headaches, and myalgias. A maculopapular rash can appear on the torso and arms in up to half the cases.
• Though the illness is often self-limited, resolving in a week to 10 days, it can occasionally cause very severe problems, including meningo-encephalitis.
• The diagnosis can be made by sending serum for West Nile viral IgM antibodies in patients with suggestive symptoms.
• Treatment is principally supportive. Those patients who become seriously ill are best treated as inpatients, and occasionally anti-viral medication is needed.

As we all learned in our medical training, prevention is always to be preferred when possible. Our mothers also taught us this when they advised that a stitch in time saves nine (though truth be told, I was never quite clear what that meant). A few key points on prevention of West Nile infections which we can pass on to our patients:

• Mosquitos like to go out foraging at sunset, so people should be especially careful in the hours around the time the sun goes down.
• Wearing DEET-based insect repellant can be helpful.
• Wearing long-sleeved shirts, pants, and socks can lessen the opportunity for mosquitos to enjoy you as a snack.
• Make sure windows are screened.
• Eliminate any sources of standing water around your house.

If any questions arise regarding the possibility that a patient you are seeing may have West Nile virus, your friendly local infectious disease specialist or county public health officer should be able to provide help.

Richard Fleming, MD