OC Reports First West Nile Virus Case – What You Need to Know

An Orange County man tested positive recently for West Nile virus (WNV) infection, becoming the county’s first human WNV infection in 2015. The man has CHOC Children's Infectious Diseasenow recovered.

As of August 12, there are 36 human cases of WNV reported in California. Last year, there were 280 reported human infections of WNV and nine WNV related deaths in Orange County. The disease is recurring every year during the summer months and into the fall, according to county health officials.

For answers on how to protect your family from this virus, check out the following Q&A with Dr. Jasjit Singh, pediatric infectious disease specialist at CHOC Children’s.

Q: What is West Nile virus and who is at risk for infection?

A: West Nile virus is transmitted by the bite of an infected mosquito. Serious illness can occur in people of any age. However, most cases of human infection occur in the elderly and in those with impaired immune systems.

Q: What are the symptoms?

A: The vast majority of WNV infections (~80%) are asymptomatic. Most symptomatic patients will have fever, sometimes accompanied by other nonspecific signs such as headache, nausea, vomiting or rash. Less than 1% of infected individuals will develop a neurologic disease, such as meningitis, encephalitis (inflammation of the brain) or acute flaccid paralysis.

Q: What is the treatment?

A: No vaccine or specific antiviral treatments for West Nile virus infection are available. Over-the-counter pain relievers can be used to reduce fever and relieve some symptoms, however. In severe cases, particularly those with neurologic involvement, patients often need to be hospitalized.

Q: How can families protect themselves from this virus?


  • Eliminate standing water on your property, which can serve as a breeding area for mosquitoes.
  • Install door and window screens, to prevent mosquitoes from entering the home.
  • When possible, avoid being outdoors between dusk and dawn when mosquitoes are most active.
  • When outdoors, if possible, wear long pants and long sleeves and use an insect repellent during the summer and fall. Look for repellents containing DEET, picardin or oil of lemon eucalyptus, which often provide longer-lasting protection.

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Who Needs a Flu Vaccine?

Practically everyone. This year’s seasonal flu vaccine is recommended for everybody 6 months and older. That includes healthy kids, as well as those with medical conditions. And it also includes you, Mom, especially if you are pregnant. Did you know the flu vaccine will protect you and your baby now — and your baby for the first few months of life?

CHOC Children’s infectious diseases specialist Jasjit Singh, M.D., has some helpful answers to questions we’re frequently asked about the seasonal flu vaccine.

Q. Why does a healthy child need a flu vaccine?
A. A child’s health status does not automatically prevent some of the serious complications associated with the flu. Children under 1 year of age who get the seasonal flu have extremely high rates of hospitalization. And in the last few years, half of the pediatric deaths from influenza have occurred in previously healthy children. This year’s flu vaccine protects against two new influenza strains, plus the H1N1 virus.

Q. My baby is younger than 6 months — how can I protect him during flu season?
A. Make sure that everyone in your home — siblings and grandparents, too — and daycare providers get a flu vaccine. This reduces the likelihood of your baby coming into contact with the virus. Also important: Wash your hands and use respiratory etiquette during flu season. There are many other respiratory viruses out there besides the seasonal flu, and the flu vaccine cannot protect against all of them.

Q. I’ve been hearing about “herd immunity” — what is that exactly?
A. Herd immunity protects the youngest, most vulnerable members of our community who cannot get the flu vaccine. When more members of the community are immunized, there is less chance of an influenza outbreak.
Also, some children have weak immune systems and remain vulnerable even after getting the flu vaccine. Their protection depends on herd immunity, as well.

Q. I’ve heard there is a nasal mist alternative to the shot.
A. The traditional flu shot is approved for children 6 months and older. The intranasal flu vaccine is an option for healthy kids 2 and older.

Earlier is better, but it’s not too late to get a flu vaccine. Contact your pediatrician.

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