top of page
Ayşe Defne Orhan

West Nile Virus Spreads Rapidly Worldwide: a New Outbreak Coming?

West Nile virus continues to spread to countries all over the world, raising concerns.

In Seville, Spain, protests took place as 61 cases of West Nile virus have been registered, leading to 5 deaths this summer, which is the second most recorded cases in a year, after 2020. Notably, all of the cases were reported from the Lower Guadalquivir Valley area near Seville since it provides an ideal habitat for the propagation of mosquitoes with large rice fields and marches. Protesters urge authorities to take action against the disease, demanding the government cooperate with local authorities to combat the disease. According to Jordi Figuerola, of the Spanish National Research Council (CSIC), mild winter and wet spring accelerated the spread of the disease, and the circulation of the West Nile virus will likely keep increasing.


Furthermore, Greece’s public health authority, the Hellenic National Public Health Organization (EODY), issued a warning on Monday about the West Nile virus, with the statement “The circulation of the virus is particularly intense during the current 2024 transmission season, with the number of recorded cases is higher compared to the previous five years for the same time period,” advising citizens to take preventive actions against mosquitoes including wearing insect repellents, mosquito nets, and avoiding stagnant water bodies, breeding grounds for mosquitoes, particularly between dusk and dawn.


Similarly, Israel witnessed the West Nile virus outbreak with over 800 cases in 2024, the biggest number of cases reached in more than two decades. To better exemplify, there were 49, 35, and 38 cases of West Nile diagnosed respectively in 2023, 2022, and 2021, in Israel, as Health Ministry data demonstrate. While 61 people died from the virus since June 2024, The Environmental Protection Ministry has required all authorities to further extend their monitoring and pest control measures. The Ministry also stated that the virus outbreak began earlier than usual as the cases started to emerge as early as June, because the virus in fact has been typically carried the most in August and September. The early outbreak is possibly due to climate change.

The virus that was first spotted in New York in August 1999 has since spread to most states, 38 to be exact, of the US and the 377 human cases were confirmed this year as of September 3, 2024. For example, 27 cases of West Nile have been reported in Mississippi, in 2024 alone, and the virus killed 2 people. Likewise, in New Jersey, 2 people died from the virus.


Former director of the National Institute of Allergy and Infectious Diseases, Dr Antony Fauci has also been infected with the West Nile virus lately and is now recovering at home after 6 days of being hospitalized. He is expected to recover fully as the spokesperson stated.


In Europe, as of September 5, 2024, 15 countries have reported West Nile virus including Albania, Austria, Bulgaria, Croatia, France, Germany, Greece, Hungary, Italy, Kosovo, North Macedonia, Romania, Serbia, Spain, and Türkiye, in 2024.

Türkiye’s Ministry of Health announced that 6 people were diagnosed with West Nile virus in 2024, whose treatments continue. The Ministry remarked that the virus has been present in Türkiye since 2010. However, the estimated number of infected individuals has recently risen to 3000, raising concerns.


As Professor Dr. Ahmet Özbek from Altınbaş University told Hürriyet, Türkiye, a country that is characterized by a Mediterranean climate has become vulnerable to vector-borne diseases, especially ones transmitted through mosquitoes, such as West Nile, dengue fever, Zika, and malaria as a result of climate change and elevated temperatures. Importantly, not only does Türkiye get directly affected by climate change and global warming with the escalated risk of tropical disease, but the whole world faces a similar threat since heat facilitates the life cycle of organisms carrying the pathogens, thus easing the transmission and spread of the diseases, yielding, new potential global outbreaks.


According to a study published in Nature Communications, climate change and overpopulation increase the risk of people being exposed to the West Nile virus than before.


What is West Nile Virus?

West Nile Virus belongs to the flavivirus genus and the Japanese encephalitis antigenic complex of the family Flaviviridae. The virus was first identified in a woman in the West Nile district of Uganda in 1937. Plus, it was discovered in birds (crows and columbiformes) in the Nile Delta region once again in 1953.

The most common transmission to humans is primarily through the bite of infected mosquitoes that have gotten the virus when they feed on the infected bird. Hence, West Nile virus is maintained in the environment between mosquitoes and birds, as birds are the natural hosts and mosquitoes are the vectors transmitting the virus. Notably, humans are the dead-end hosts, meaning they do not further spread the virus. A very small proportion of spread has occurred via organ transplantation, blood transfusions, and breast milk. There is only one reported case of mother-to-child transmission according to WHO; therefore, human-to-human transmission is very rare. Nonetheless, as a precaution, people diagnosed with West Nile virus should not donate blood or bone marrow for 120 days following infection.


The majority of infected people do not show any symptoms, considering about 1 in 5 people develop symptoms including fever, headache, body aches, vomiting, diarrhea, or rash, and about 1 in 150 patients develop a severe illness with symptoms including headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, paralysis, and neurological infections such as meningitis or encephalitis, that can be fatal. People over 50 are at a higher risk.

Cases of West Nile arise during mosquito season, which is from summer until fall. There are currently no vaccines to prevent or medications to treat the disease; thus, it is crucially important to reduce the exposure to mosquitoes and prevent mosquito bites. Experts recommend wearing covering clothes, using repellents, and window screens, and using insecticide-treated bed nets while staying away from and removing standing water sources where mosquitoes can easily breed.


Time will show whether West Nile will evolve into an outbreak. Regardless of whether it does or not, it is crucial to learn more about this prevalent disease that seems to become even more common every day. Especially, people should accustom themselves with the prevention techniques as West Nile cases rise worldwide.


Comments


bottom of page