West Nile Virus

West Nile virus (WNV) infection is a mosquito-borne zoonosis. The virus is transmitted among birds via the bite of infected mosquitoes and incidentally, humans and other mammals may become infected.

Humans get West Nile from the bite of an infected mosquito. Usually, the West Nile virus causes mild, flu-like symptoms. The virus can cause life-threatening illnesses, such as encephalitis, meningitis, or meningoencephalitis.

West Nile virus (WNV), a single-stranded RNA virus belonging to the family of Flaviviridae, is an arbovirus transmitted to humans predominantly by mosquito bites.

It exhibits a wide range of clinical findings ranging from asymptomatic presentation to severe several neurological disorders. WNV has afflicted several countries around the globe including Pakistan. News of yet another outbreak in the country by WNV is circulating again. Concerned authorities should act vigilantly before the endemic takes over completely and bring down the already bereaving healthcare of Pakistan.

Prevalence of WNV in Pakistan:

Pakistan has been under its pounce with WNV RNA detected in 33.3% of the population. Another report found seropositivity for the virus in 65% of the samples collected. Serological testing and detection of WNV in the local population of Pakistan dates to as early as 1982, while the most recent outbreak was recorded in 2015–16. Currently, reports of the WNV outbreak are circulating again. According to an infectious diseases specialist from a renowned hospital in the country, the clinical presentation of patients in the hospital along with a massive number of crows’ and birds’ death, highly suggests that the country is facing an outbreak of WNV once again.

However, due to the lack of testing facilities, there is a long way to a confirmatory conclusion. There can be multiple reasons for the potential outbreak, however, previous literature cites that lack of adequate testing centres, poor sanitation, inadequate lifestyles, absent surveillance system, flooding, geopolitical instability, and easy access to neighbouring countries via the construction of highways have made Pakistan, more prone to arboviral infection, primarily Crimean-Congo haemorrhagic fever virus (CCHFV), WNV, Chikungunya virus (CHIKV), and Dengue viruses (DENV).

Vaccination Against West Nile virus:

Currently, there is no licensed WNV vaccine for people. In 2005, the U.S. Department of Agriculture licensed a DNA vaccine to prevent WNV in horses, and since then, at least four other types of WNV vaccines have been approved for use in horses. Treatment includes supportive therapies at hospital.

References

– Waseem, S., Shaikh, T. G., Ahmed, S. H., Usama, R. M., Asghar, M. S., & Tahir, M. J. (2022). West Nile virus outbreak in Pakistan: Another potential public health threat in the pipeline?. Annals of Medicine and Surgery, 77, 103663.

Turner, J., 2020. West Nile Virus in Horses | New Mexico State University. [online] Pubs.nmsu.edu. Available at: <https://pubs.nmsu.edu/_b/B719/index.html> [Accessed 11 August 2022].