Preventing California Encephalitis

California encephalitis (CE) is a viral infection impacting the brain with potential neurological complications, leading to inflammation.⁴ This infection is commonly seen in children but rarely in adults and is transmitted by various factors such as Mosquito-borne transmission by Aedes and Culex species as vectors causing viral infections like pediatric encephalitis, with a focus on herpes simplex encephalitis (HSE).^4,5,6 This rare yet serious illness can result in neurologic disability and death.³

Recent data highlights the reemergence of St. Louis encephalitis virus (SLEV), a causative agent for CE.⁹ Although the risk is relatively low, preventive measures are crucial. This article explores simple and practical ways for everyone to incorporate daily life practices to minimize the risk of California encephalitis infection.

Understanding California encephalitis

This viral infection affecting the central nervous system remains a significant public health concern and has historically been observed in California leading to outbreaks and cases.^2,8 California encephalitis, caused by California group arboviruses (airborne virus) manifests as a severe neurological syndrome with substantial morbidity and mortality, particularly affecting children.²

Causative viruses

• California encephalitis is caused by various viruses, including the La Crosse virus being endemic to the Midwestern United States and tick-borne encephalitis viruses⁴
• Other causative viruses encompass enteroviruses, herpes simplex virus, West Nile virus, and California serogroup viruses like La Crosse virus, Jamestown Canyon virus, and Snowshoe Hare virus^2,5,8,10
• SLEV, a flavivirus, is the primary causative agent, transmitted through the bite of infected mosquitoes, particularly of the Culex species^.8 These Mosquitoes acquire SLEV from infected birds and transmit it to humans acting as an amplifying host⁸
• A newly recognized phenotype, Acute Fulminant Cerebral Edema (AFCE), associated with encephalitis, exhibits a high mortality rate, especially in children⁷

Modes of transmission

• Transmission occurs primarily through mosquito bites or ticks, with activities like camping and hiking thereby increasing exposure risk⁴
• Direct contact with infected people or contaminated surfaces can lead to infections with human-derived viruses⁴
• Mosquitoes act as vectors, carrying viruses from infected hosts to humans during blood-feeding, emphasizing the importance of preventive measures against mosquito bites^3,8,2

 This virus causes inflammation of the brain leading to symptoms such as:

Symptoms to be aware of

Mild

• fever, headaches, nausea, vomiting, seizures, altered consciousness, and focal neurological signs⁶
• confusion, disorientation, and muscle weakness¹⁰ 
• Psychiatric symptoms such as fear, anxiety, hallucinations, and personality changes are common, alongside movement disorders, speech difficulties, and cognitive impairment (difficulties in mental processes such as thinking, memory, problem-solving, and perception)¹
• Patients may also experience flu-like symptoms and the severity can vary among individuals, however, in some cases, it progresses rapidly³

Severe

Neurological complications:

• Neurological complications may arise, including dystonia, spasticity, epilepsy, ataxia, and neurocognitive and behavioural problems⁶
• Progression of these symptoms can lead to complications like paralysis, and coma, and impact the central nervous system, significantly affecting the individual's quality of life⁸
• Long-term management and support may be required for these complications⁶
• Personality changes in children emphasise the need for early detection and management⁵

Diagnostic procedures to assess CE

• Blood Tests and serological tests help confirm the diagnosis and identify the specific virus causing the infection¹²
• Viral Culture¹²
• Cerebrospinal Fluid Analysis¹²
• Neuroimaging, such as magnetic resonance imaging (MRI) or computed tomography (CT) scans¹²
• Polymerase Chain Reaction (PCR) Tests¹²
• Electroencephalogram (EEG)¹²

Advice on when to consult medical assistance

When experiencing symptoms like fever, headache, and neurological abnormalities, consult a physician immediately, who will conduct a thorough medical evaluation to assess the possibility of CE.⁷

Preventive measures of CE

Mosquito bites are the primary mode of transmission, necessitating preventive strategies like avoiding mosquito bites and staying informed are crucial for reducing the risk factors.¹⁰

Tips to reduce mosquito-borne transmission

Mosquito repellent

• It is important to use mosquito repellents containing DEET, picaridin, or oil of lemon eucalyptus to protect against mosquito bites
• Apply the repellent on exposed skin and clothing to create a barrier against mosquitoes⁹

Wearing protective clothing

• Wear long-sleeved shirts, long pants, socks, and closed shoes to minimize skin exposure and reduce the risk of mosquito bites
• When engaging in outdoor activities, ensure that clothing covers as much skin as possible to prevent mosquito bites⁹

Avoiding peak mosquito activity

• Recognize times of increased mosquito activity, such as dawn and dusk, when mosquitoes are most active
• Limit outdoor activities during peak mosquito activity times to lower the chances of being bitten⁹

Window and door screens

• Ensure that windows and doors have proper screens to keep mosquitoes out of living spaces
• Repair or replace damaged screens to maintain effective protection against mosquito entry⁹

Environmental management 

• Remove sources of standing water, which serve as breeding grounds for mosquitoes¹¹
• Regularly empty and clean water-collecting containers to prevent mosquitoes from laying eggs and multiplying¹¹
• Community efforts: advocate for community-wide mosquito control measures, such as insecticide spraying and reducing the mosquito population, to prevent the spread of California encephalitis at a broader level¹¹

Travel precautions

• Use bed nets treated with insect repellent when traveling to areas with a high risk of mosquito-borne diseases⁹
• Choose accommodations with proper screening on windows and doors to prevent mosquito entry⁹

Homemade remedies 

Citrus repellent spray

Ingredients: Citrus peels (lemon, orange, or grapefruit), boiling water, and witch hazel or vodka.

Steps:

• Collect citrus peels and place them in a bowl
• Pour boiling water over the peels and let them steep overnight
• Strain the liquid and mix it with an equal amount of witch hazel or vodka
• Transfer the mixture to a spray bottle and apply to exposed skin

Lavender and eucalyptus oil blend

Ingredients: Lavender oil, eucalyptus oil, and a carrier oil (such as coconut or olive oil).

Steps:

• Mix 10-15 drops each of lavender and eucalyptus oil with a carrier oil
• Apply the blend to your skin before heading outdoors

Neem oil repellent

Ingredients: Neem oil, coconut oil, or another carrier oil.

Steps:

• Mix neem oil with a carrier oil (neem oil has a strong odour, so diluting it helps)
• Apply the mixture to exposed skin

Apple cider vinegar spray

Ingredients: Apple cider vinegar, water, and essential oils (optional).

Steps:

• Mix equal parts water and apple cider vinegar
• Add a few drops of essential oils for additional fragrance
• Apply the mixture to your skin or clothing

Herb garden protection

• Plant mosquito-repelling herbs like citronella, basil, mint, and rosemary around your home
• Crush the leaves and rub them on your skin for added protection

Remember to do a patch test before using any homemade remedy to ensure you don't have an adverse reaction. While these remedies can be effective, it's essential to reapply them more frequently compared to commercial repellents. Additionally, for areas with a high risk of mosquito-borne diseases, using professionally formulated mosquito repellents may be recommended for more robust protection.

Treatment

The treatment of California encephalitis involves supportive care to manage symptoms and complications. There is no specific antiviral therapy available for most cases of viral encephalitis, including California encephalitis.³ Patients may require hospitalization for close monitoring and supportive measures such as intravenous fluids, anticonvulsant medications for seizures, and respiratory support if needed.³

In severe cases, patients may need intensive care management to address neurological complications and prevent further deterioration.³ Early detection and prompt initiation of supportive treatment are essential in improving outcomes for individuals with California encephalitis.

Further research

Additional research is essential to further investigate the development of vaccines designed to combat California encephalitis viruses. Immunization stands out as an enduring solution, acting to impede the spread of the disease and protect vulnerable groups, such as children and the elderly, who may be more prone to severe complications.

FAQs

How can you protect yourself from encephalitis?

Protect yourself from encephalitis by using mosquito repellent, wearing protective clothing, and avoiding peak mosquito activity. Install screens, eliminate standing water, and stay informed about outbreaks. Seek medical attention promptly for symptoms.

How is California encephalitis transmitted?

California encephalitis is primarily transmitted through the bites of infected mosquitoes. When mosquitoes carrying the California encephalitis virus bite a human, the virus can be transmitted into the bloodstream, leading to infection and the potential development of encephalitis.

What is the mortality rate of California encephalitis?

Most cases of LAC virus-induced acute CNS disease occur in children under 15, affecting males more than females. The mortality in acute CNS disease is around 1%. Mortality rates for California encephalitis vary; it is generally low, but severe cases can pose a risk, influenced by factors such as overall health, timely medical intervention, and virus strain. Seeking prompt medical attention is crucial.

Who is most likely to get encephalitis?

Encephalitis can affect anyone, but young children, the elderly, individuals with weakened immune systems, and outdoor enthusiasts are more susceptible. Vaccination, hygiene, and preventive measures reduce risks. Prompt medical attention is crucial.

What triggers encephalitis?

Encephalitis can be triggered by various factors, including viral infections (commonly herpes simplex virus), bacterial infections, autoimmune disorders, and certain environmental factors. Identifying and treating the underlying cause is essential for effective management.

What are the warning signs of encephalitis?

Encephalitis manifests with symptoms such as sudden high fever, severe headaches, altered mental state, seizures, neck stiffness, sensitivity to light, nausea, and vomiting. Prompt medical attention is essential when these warning signs appear to ensure accurate diagnosis and timely treatment.

Can COVID-19 trigger encephalitis?

Yes, COVID-19 can potentially trigger encephalitis. Reports have indicated cases of encephalitis associated with COVID-19, although such cases are rare. The exact mechanisms and prevalence are still being studied, highlighting the importance of ongoing research in understanding COVID-19-related neurological complications.

What is the life expectancy of someone with encephalitis?

The life expectancy of someone with encephalitis varies widely based on several factors, including the underlying cause, the severity of the infection, and the promptness of medical intervention. In many cases, with timely and appropriate treatment, individuals can recover fully.

However, severe cases, especially those leading to significant neurological complications, may have a more guarded prognosis. It's crucial to seek medical attention promptly for accurate diagnosis and appropriate management to optimize outcomes. The prognosis is highly individual, and discussions about life expectancy should be tailored to the specific circumstances of the affected person.

Can the brain recover from encephalitis?

The brain has the potential to recover from encephalitis, but the extent of recovery varies. Timely and appropriate medical treatment is crucial to minimize damage. Some individuals may fully recover, while others may experience residual effects such as cognitive deficits, memory issues, or behavioural changes.

Rehabilitation and supportive care play vital roles in optimizing recovery and managing long-term effects. The degree of recovery depends on factors such as the severity of the encephalitis, the specific areas of the brain affected, and the individual's overall health. Regular follow-up with healthcare professionals is essential to monitor progress and address ongoing needs.

Can stress cause encephalitis?

Stress itself is not a direct cause of encephalitis. Encephalitis is typically caused by infections, including viral, bacterial, or other pathogens. Stress, however, can impact the immune system, potentially making individuals more susceptible to infections. It is crucial to manage stress for overall health, but encephalitis is generally triggered by infectious agents rather than stress alone.

Summary

California encephalitis (CE) is a viral brain infection primarily affecting children, transmitted mainly through mosquito bites, particularly by Aedes and Culex species. Symptoms range from mild flu-like signs, such as fever and headache, to severe neurological complications like seizures and paralysis. Diagnosis involves blood tests, cerebrospinal fluid analysis, imaging, and PCR tests, while treatment focuses on supportive care, as no specific antiviral exists.

Preventive measures include using mosquito repellents, wearing protective clothing, avoiding peak mosquito activity, and eliminating standing water. Ongoing research aims to develop vaccines to prevent CE and protect vulnerable populations.