Introduction
Infections have been a great cause of human disease and death for a very long time. Even with scientific advancements and technological research, eradicating infectious agents seems impossible. One such important infectious agent causing human havoc is the West Nile virus. Having been identified first in Uganda in 1939, this virus causes disease manifestations that can result in severe illness.
How Does West Nile Virus Infection Affect Humans?
West Nile virus belongs to the flavivirus group and causes diseases in birds. However, through a vector like a mosquito, this infection spreads to human beings.
Humans get infected with this virus through the bite of a vector. In this case, the vector is the mosquito, and the common mosquitoes involved are the Culex species. Culex pipiens and Culex quinquefasciatus are the common culprits in the causation of West Nile virus infection in humans. These mosquitoes carry the virus from infected birds and transmit it to human beings while biting.
After entering the human body, the virus reaches the individual's bloodstream, multiplying by replicating in the body. The first sites affected by the virus are the skin and lymph nodes. The human body's immune system tries to respond to the antigen as a first reaction to a foreign antigen (West Nile virus). This can cause symptoms like fever, headache, malaise, or fatigue. Even without any kind of medical intervention, this resolves.
In advanced cases, severe complications can be associated with West Nile virus infection. The complication is mainly because the virus can surpass the blood-brain barrier. This can lead to neuroinvasive diseases like inflammation of meninges (meningitis) or the brain itself (encephalitis). When such an important organ is affected, it can cause severe symptoms like persistent headache, stiffness of the neck, seizures, disorientation or a state of confusion, tremors, seizures, paralysis, or coma.
All such manifestations indicate that the ability of a human immune system to combat such viral infectious agents is very important for the causation and spread of infection.
How to Diagnose West Nile Virus Infection?
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Medical history with clinical examination is the first step in diagnosing West Nile virus infection. On eliciting signs and symptoms of West Nile virus infection like fever, malaise, neck stiffness, or disorientation, patients should give a history of mosquito bites to confirm the diagnosis. So, clinical signs and evaluation are important, especially to pinpoint neurological manifestations.
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Once there is a suspicion that the person could be infected with West Nile virus, the patient would be subjected to laboratory investigations for confirmation. Laboratory investigations detect and identify antibodies produced against the West Nile virus.
Serological Investigations:
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To detect antibodies against the virus, the affected individuals' serum or cerebrospinal fluid will be collected to identify IgM antibodies. This process will be done after eight to 21 days of getting infected or initiating symptoms.
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The MAC-ELISA (IgM antibody capture enzyme-linked immunosorbent assay) is the preferred method to identify the IgM antibodies.
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For IgG antibodies, immunoglobulin G ELISA is employed. A count greater than 1.5 IV in the sample specimen indicates a present infection.
Molecular Investigations:
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Even when no antibodies are present, West Nile viral particles in the human body can be used to detect the infection.
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This can be detected from the suspected individual's whole blood, serum, or urine sample.
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A polymerase chain reaction helps detect the West Nile virus RNA particle.
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This procedure is done three to five days after symptoms start.
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This helps in early detection and treatment of West Nile virus infection.
Radiographic Investigations:
Radiographic investigations become essential only in cases of neurological manifestations. This involves subjecting the patient to CT and MRI scans to identify and assess the extent of involvement of the spine and brain. This also helps in treating encephalitis and meningitis accurately.
West Nile virus infection is a kind of infection that could mimic various other conditions like dengue fever, Zika virus infection, or influenza. Thus, doctors may prescribe various tests to pinpoint the causative infectious agent.
How to Treat West Nile Virus Infection?
Symptoms will be treated as no specific curative agent for the infection exists. Non-steroidal anti-inflammatory agents will be prescribed first to reduce the severity of symptoms. In cases of neurological invasion and manifestations, hospitalization may be necessary to control seizures and prevent coma.
How to Prevent West Nile Virus Infection?
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Mosquitos are the chief culprits in the causation. So, preventing mosquito bites is the first step to preventing West Nile virus infection. Any source, like stagnant water or clogged gutters that could serve as a source for mosquito breeding should be eliminated immediately.
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Use repellents that help protect the skin. Insect repellents with Picaridin or eucalyptus oil can be helpful.
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Once the pathophysiology is well-known, preventing West Nile virus infection becomes easy. West Nile virus is a kind of infection that is not transmitted by direct human contact. However, it can be transmitted through donated organs or transfused blood. Hence, any donated organ and blood should be screened thoroughly.
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The most important tool is a vaccine to prevent any kind of infection. Research should be emphasized on developing vaccines against the West Nile virus.
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Monitoring mosquito populations and their infection rates helps identify high-risk areas and guide targeted control measures. This comes as a procedure of vector surveillance and control.
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Also, tracking human cases and their geographical distribution aids in understanding the spread of the virus and implementing preventive strategies.
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Every society should know the seriousness of letting mosquitoes breed, irrespective of its economic strata. People should be taught how diseases such as mosquitoes could spread as a community. This can help the horizontal and vertical transmission of knowledge of the West Nile virus. This will play a major role in preventing West Nile virus infection.
Conclusion
West Nile virus infection has been a cause of sporadic outbreaks in various regions over a very long time. Diagnosing the presence of West Nile virus early is important to prevent neuroinvasive diseases. Also, preventive measures should be implemented early to stop any outbreak or pandemic.
