Filenews 5 September 2023
The Medical and Public Health Services of the Ministry of Health inform the public that they are aware of the existence of the first case of West Nile Virus (WNV) for 2023.
In Cyprus, sporadic cases occur from time to time, mainly during the summer months. Specifically, according to data maintained by the Epidemiological Surveillance and Control of Infectious Diseases Unit, in 2016 one case was declared, in 2018 one case and in 2019, 24 cases.
It is recalled that IDN is transmitted mainly by the bite of infected "common" mosquitoes. People who are infected are thought not to transmit the virus further to other people. IDD is not transmitted from person to person, it is not transmitted through normal social, sexual or other contact. It is also not transmitted from hospitalized patients to medical and nursing staff.
After the mosquito bite, it usually takes 2-14 days (incubation time) until the onset of symptoms.
In the majority of cases, people infected with the virus show no symptoms or have mild symptoms, while very few people (less than 1%) develop severe disease affecting the nervous system (encephalitis, meningitis or paralysis). Older people (over 50 years old) as well as people with immunosuppression and chronic underlying diseases are more at risk of becoming seriously ill.
West Nile Virus is transmitted:
1. From infected mosquitoes. IDN is transmitted by the bite of an infected mosquito. Mosquitoes become infected when in contact with infected birds. Infected mosquitoes can transmit the virus to humans and animals by being bitten.
2. With transfusions, transplants and rarely from mother to foetus. In a very small number of cases, IDN can also spread directly from an infected person through blood transfusions, organ transplants, breastfeeding, and during pregnancy from mother to baby (vertical transmission). The Epidemiological Investigation Unit and the Infectious Diseases Unit of the Health Services in cooperation with the Health Services carry out an epidemiological investigation of each reported case, and additional measures are taken to combat mosquitoes where appropriate.
The measures include the following:
• Strengthening surveillance of suspicious incidents
• Epidemiological investigation of each case separately
• Frequent communication and exchange of information with the laboratories performing the relevant diagnostic tests
• Measures for the safety of blood and blood transfusion
• Intensification of mosquito control measures by the Health Services
• Communication with public health bodies abroad, such as the European Centre for Disease Prevention and Control where cases are reported on a weekly basis
PSOs continue to take all necessary measures and urge the public to follow the preventive personal and protective measures.
Individual prevention and protection measures at home
• Use of appropriate clothes, long sleeves and trousers mainly, from afternoon to morning
• In case the problem is very severe, insect repellent can be used outdoors. Insect repellents containing DEET, picaridin, IR3535 or eucalyptus essential oils last longer. Use is always according to the manufacturer's instructions
• Pregnant and lactating women should follow their doctor's instructions, while insect repellents with DEET are contraindicated in infants under two months of age and should be used according to the manufacturer's instructions. Insect repellents with eucalyptus essential oils are contraindicated in children younger than three years
• Installation of mosquito nets (mosquito nets) that prevent mosquito nets from passing through windows and doors
• Use of mosquito nets in areas with high mosquito density or in cases where the use of other protective means is contraindicated (such as the use of insect repellents with DEET, in infants younger than 2 months)
• Removal of stagnant water from basins, jars, pots, old tires, gutters and other parts of the garden, so that mosquitoes do not have access to stagnant water, which is a hatching point for their eggs
• Use of fans or air conditioners: Cool air reduces mosquito activity but does not kill them. The use of fans (especially ceiling fans) makes it difficult for insects to approach
• Mowing grass, shrubs and foliage (places where adult mosquitoes find shelter)
• Watering should preferably be done during the morning hours
• Use of yellow lamps for outdoor lighting (attract mosquitoes to a lesser extent)
• Use of insecticides containing pyrethroids (e.g. permethrin). They are commercially available in the following forms: aerosols, tablets, evaporative solution, spirals ("snakes"), etc. Insecticides should not be applied to the skin. In all cases, the manufacturer's instructions for use should be followed
• Replacement of broken water pipes that leak and removal correction of old tires that accumulate water
• Cover with screens of the ventilation ducts of the cesspools
• If there is a pool or fountain in the house, then the cleaning filters are activated daily to remove mosquito eggs and larvae
The PSOs stress that there is no cause for concern, due to the fact that the virus is not transmitted from person to person. However, the Ministry of Health is vigilant and takes all appropriate measures.
In case of a suspected case of West Nile virus infection, the Infectious Diseases Surveillance and Control Unit should be informed at: 22605759, 22605652, Fax: 22771496, e-mail: Cycomnet@cytanet.com.cy.
How does West Nile virus infection manifest itself?
No symptoms in most people: 80% of people infected do not show symptoms of the virus.
Mild disease: 20% of those infected may develop a mild form of the disease with symptoms such as fever, fatigue, headache, muscle and joint pain, gastrointestinal symptoms such as vomiting, diarrhea, anorexia, abdominal pain, rash and, rarely, swollen lymph nodes. The disease passes on its own, usually in 3-10 days.
Severe symptoms in few people.
About 1 in 150 people (less than 1%) infected with IDD will develop severe disease affecting the central nervous system (meningitis, encephalitis or acute flaccid paralysis). Symptoms may include high fever, headache, neck stiffness, consciousness level disorders (apathy, lethargy, confusion or coma), neurological symptoms (unsteadiness, gait disturbances, tremors, convulsions, paralysis, visual disturbances). These symptoms can last for several weeks, and neurological manifestations can be permanent.
