State Epidemiologist Kristy Bradley chatted with readers and answered questions about West Nile virus Wednesday. Read the entire chat recap here.
Topics discussed include: how to protect infants from mosquito bites and becoming infected, the number of West Nile cases reported in Oklahoma, development of a vaccine for the virus, when you might start to see symptoms and what age groups are at risk of becoming infected with the disease.
On Oklahoma West Nile cases:
Yesterday the State Health Department reported a total of 55 cases of West Nile disease confirmed so far this year and one related death. This is a much higher number than we've seen in previous years -- during 2008-11 combined, Oklahoma only had a total of 21 cases. We are on track for 2012 to be the most severe WNV season of record.
Because of the relatively high numbers of WNV cases that are being reported by hospitals, doctors and laboratories, we also have a number of case reports under investigation. The State Health Department will be updating our case statistics every Tuesday and Thursday on our website.
On developing a vaccine for the virus:
It has always been frustrating to me that we have had a very effective WNV vaccine to protect horses since 2003, but we don't have one to protect people! Two companies were in the process of developing a human WNV vaccine a few years ago, but since there have been no further progress on either of these vaccines, I fear that the companies determined it wasn't a profitable venture.
On how to protect infants:
There are mosquito repellent products that are labeled for use in small children. These are usually have very low concentrations of DEET in them. During stroller time, you may want to consider placing a mosquito net to shield your baby.
As a follow up to the question about protecting infants from mosquito bites, I want to add that although that is important, most children seem to have very mild illness associated with West Nile virus infection.
On age groups at risk:
Adults, especially those over 40-50 years of age are at greatest risk of developing the severe neurologic illness associated with West Nile virus infection.
Persons over the age of 50 are at greatest risk of getting the very severe illness associated with WNV. We also tend to see a higher risk of the West Nile encephalitis or meningitis in persons with diabetes, hypertension, or medical conditions that suppress the immune system.
On West Nile symptoms:
If a person was bitten by a mosquito infected with WNV, signs and symptoms of illness may show up within 2-14 days of the mosquito bite. Keep in mind, though, that many persons may have no symptoms of illness or only a very brief period of fatigue or headache.