West Nile fever continues to spread: this is the situation now in Israel

The outbreak of West Nile fever continues to claim victims: the Ministry of Health updates that so far 48 people have been diagnosed with West Nile fever, of which 36 people have been hospitalized, five of whom are on ventilators. A total of four people who were diagnosed with the virus died, and a suspicion that another person suspected of having the virus died was investigated.

West Nile fever disease is caused by infection with a virus that resides in the wild among birds. The course of the disease begins with mosquitoes that bite birds and transmit the virus to them, which continues to live in the birds’ bodies. In the next step, the mosquitoes bite again, and transmit the virus to animals and humans.
This is a mild disease for the most part, but it can also cause severe morbidity and mortality. The infection usually passes without symptoms. In some cases, a flu-like illness appears which goes away on its own. Symptoms include fever, headache, weakness, joint and muscle pain, conjunctivitis, rash and sometimes nausea and diarrhea.

In about 1% of cases the disease becomes severe, with neurological signs corresponding to meningitis, acute encephalitis or acute flaccid paralysis. The incubation period is usually 7 to 14 days, and in exceptional cases three to 21 days. The disease does not pass from person to person. At high risk are patients with chronic diseases that suppress the immune system, cancer patients with poor immune systems, infants and the elderly. According to the medical literature, the virus is transmitted in nature only by infected mosquitoes, and there is no evidence to suggest infection from an animal to humans. There is no vaccine for humans against the virus. Currently, a vaccine exists only for protection in horses.

There is no specific treatment for the disease. Today, attempts are being made to administer an intravenous infusion of antibodies called IVIG and the drug interferon, thinking that they will strengthen the immune system’s ability to eliminate the virus spreading in the body. Meanwhile, the patients receive fluids, antibiotics to prevent secondary infection and, when necessary, are ventilated. The main way of coping is to prevent mosquito bites through the use of mosquito repellents, window nets and appropriate clothing and reporting to the authorities about mosquito clusters or water reservoirs.

What are the warning signs that require a visit to the emergency room after a mosquito bite?
• Prolonged fever over a week.
• Multiple vomiting with every attempt to drink.
• Failure to urinate for more than 10 hours.
• Rapid breathing (over 20 per minute in an adult, over 40 per minute in a child).
• Decreased state of consciousness.
• Aversion to light.
• Headaches that are unusual in intensity or that wake you up from sleep.