Özgöray: “Mosquito Control” Key to Preventing West Nile Virus Spread

Özgöray, President of the Veterinary Doctors’ Union, appeared as a guest on “Gündem,” a programme hosted and presented by Ulaş Barış on Kıbrıs Postası TV.

Speaking on the spread of West Nile Virus, its transmission routes and methods of combating the disease, Özgöray said the virus had been detected in more than 10 people in South Cyprus and four people in North Cyprus. He noted that the first officially recorded case in the TRNC was identified in 2016.

Most patients overcome the virus without symptoms, Özgöray said, while the risk is higher among older people and those with weakened immune systems. He stressed that preventing the spread of the virus requires “suppressing the mosquito population.”

Rather than relying primarily on spraying chemicals into the air, he said, mosquito control should focus on stagnant water where mosquitoes breed and on eliminating them during the larval stage. He also called on households to remove standing water and check the covers of water tanks.

“THE VIRUS WAS FIRST DISCOVERED IN 1937”

Providing information about West Nile Virus, which has been detected in more than 10 people in South Cyprus and four in North Cyprus, Özgöray said the virus was first discovered in Uganda’s West Nile region in 1937 and took its name from the area.

He said the virus had become a threat across all Mediterranean countries since the 2000s.

“THE FIRST OFFICIAL CASE IN THE TRNC WAS DETECTED IN 2016”

Özgöray said the first official case in the TRNC was identified in 2016.

“There were probably cases in the early 2000s, of course, but they were not detected,” he said.

Explaining the transmission cycle, Özgöray said the virus passes first from birds to mosquitoes and then from mosquitoes to humans. Under normal circumstances, he said, the virus circulates between mosquitoes and birds, while humans and horses are the two species that acquire the virus “accidentally.”

For this reason, he said, humans and horses are considered “dead-end hosts.”

“THE ‘BROWN’ MOSQUITOES THAT SPREAD THE DISEASE IN THE TRNC”

Özgöray said the mosquitoes responsible for transmitting the disease in Cyprus did not come from Uganda’s West Nile region, noting that all subspecies of the Culex genus can transmit the virus.

In North Cyprus, he said, the disease is transmitted by “brown” mosquitoes. He explained that the mosquitoes become capable of transmitting the virus to humans following changes that occur in their salivary glands.

West Nile Virus can also cause death among birds, Özgöray said, adding that sudden bird deaths can be considered one of the first signs that the virus has arrived in an area.

“THE MORTALITY RATE IS 1%”

Özgöray also responded to a question from Ulaş Barış about the mortality rate after Barış recalled that 5.7% of cases recorded in Turkey between 2010 and 2024 had resulted in death.

He said 80% of patients experience the virus asymptomatically, while 16% develop flu-like symptoms. He listed headaches, runny noses and fever among the possible symptoms, adding that neurological symptoms occur in around 3% of cases.

Özgöray said the generally accepted mortality rate for the disease is around 1%, although the rate is higher among older people and those with weakened immune systems.

He recalled that West Nile Virus had caused two or three deaths in North Cyprus in the past, adding that one of the deaths had occurred among relatives of his wife.

“WE NEED TO SUPPRESS THE MOSQUITO POPULATION TO PREVENT THE SPREAD OF THE VIRUS”

Özgöray said scientific research in Greece indicated that 80% of the virus’s movement between countries occurs through migratory birds. This means that preventing the virus from reaching new countries is not possible, he said, stressing instead that efforts should focus on “suppressing the mosquito population.”

He also said it would be incorrect to assume that no mosquito control was taking place simply because municipal spraying vehicles were not visible on the streets.

The real focus of mosquito control should be stagnant water, Özgöray said.

He explained that mosquitoes can be targeted while they are still in the larval stage, stressing: “Once you let the mosquito fly, mosquito control becomes extremely difficult.”

The chances of chemicals sprayed into the air reaching mosquitoes are low, he said, while treating mosquito larvae can achieve a mortality rate of between 99% and 100%.

“ALL SOURCES OF STANDING WATER AROUND HOMES CAN BE ELIMINATED”

Özgöray said all sources of standing water around homes could be eliminated, noting that one simple measure was to avoid leaving water in buckets.

He also warned that if the lid of a water tank is damaged, mosquitoes can enter and lay their eggs inside.

Culex mosquitoes favour large bodies of stagnant water such as tanks, ornamental ponds and unused swimming pools, Özgöray said, stressing that thousands or even tens of thousands of mosquitoes can breed in such locations.

He said there is generally no major mosquito problem in dams and lakes because of the fish living there, but added that control measures are still necessary in areas that fish cannot reach.