# Is encephalitis contagious? Canonical page: https://clinicsjo.com/en/faq/is-encephalitis-contagious Language: en Category: infectious Publisher: ClinicsJo Published: 2026-09-13T08:09:51.560Z Content updated: 2026-09-13T08:09:51.560Z Translation (ar): https://clinicsjo.com/ar/faq/is-encephalitis-contagious Encephalitis is an inflammation of the brain, and it can have various causes, some infectious and some non-infectious. In general, encephalitis itself is not considered a contagious disease that easily spreads from person to person like the cold or flu. However, some of the viruses or bacteria that cause encephalitis can be contagious and may be transmitted between individuals or through vectors like insects, which can lead to an infection that may later develop into encephalitis. For example, viruses are the most common cause of infectious encephalitis. These viruses can include herpes viruses (such as herpes simplex and Epstein-Barr virus), enteroviruses which often cause mild illnesses or respiratory infections, and viruses transmitted by mosquito or tick bites, such as West Nile virus and tick-borne encephalitis virus [\[1\]](). In these cases, the virus is contagious, not the resulting encephalitis directly. Some of these viruses can be transmitted through contact with saliva, nasal secretions, feces, or throat and respiratory secretions, meaning people living in the same house or in daycare centers or classrooms with an infected person may be exposed to the infection [\[2\]](). ## Types of Infectious and Non-Infectious Encephalitis Encephalitis can be categorized into two main types: infectious encephalitis and autoimmune encephalitis [\[1\]](). While infectious encephalitis is caused by pathogens like viruses or bacteria invading the brain, autoimmune encephalitis occurs when the body’s immune system mistakenly attacks healthy brain cells [\[2\]](). The latter type is not contagious at all. - **Infectious Encephalitis:** Usually caused by viruses, but can also be caused by bacteria, fungi, and parasites, though less commonly [\[1\]](). Viruses transmitted by mosquitoes and ticks, such as Eastern equine encephalitis virus and Powassan virus, do not spread directly from person to person; they require a vector (mosquito or tick) [\[1\]](). However, other viruses, such as herpes simplex virus, can spread from person to person through direct contact and may then cause encephalitis in some individuals [\[2\]](). - **Autoimmune Encephalitis:** In this type, the immune system attacks healthy brain cells. This can be caused by certain conditions like certain cancers, benign tumors, or even certain infections that trigger a faulty immune response [\[1\]](). This type of encephalitis cannot be transmitted between people. ## Symptoms and Signs Requiring Urgent Medical Intervention Symptoms of encephalitis vary greatly depending on severity. Many people may show no symptoms, while others may suffer from mild flu-like symptoms such as fever, fatigue, headache, and body aches [\[1\]](). However, if encephalitis becomes more severe, it may cause symptoms that require immediate medical attention: - Severe headache [\[1\]]() - Stiff neck [\[1\]]() - Vomiting [\[1\]]() - Seizures [\[1\]]() - Behavioral changes [\[1\]]() - Extreme drowsiness or loss of consciousness [\[1\]]() - Muscle weakness or partial paralysis in the arms and legs [\[1\]]() - Coma [\[1\]]() - Speech or hearing problems [\[2\]]() - Hallucinations [\[2\]]() For infants, encephalitis can be dangerous, and their symptoms may include fever, lethargy (weakness or drowsiness), poor feeding, vomiting, body stiffness, irritability or unusual crying, as well as a bulging fontanelle (the soft spot on the top of the head) [\[1\]](). If any of these symptoms appear in you or your child, it is essential to seek immediate medical care [\[1\]](). ## Diagnosis and Medical Intervention To diagnose encephalitis, a healthcare provider will perform a physical exam, take a medical history, and may order imaging tests such as a CT or MRI of the brain, an EEG to measure brain activity, as well as blood and cerebrospinal fluid tests [\[1\]](). Cerebrospinal fluid is usually collected via a lumbar puncture (spinal tap), a procedure that involves inserting a needle into the lower spine to collect a sample of the fluid surrounding the brain and spinal cord [\[3\]](). Treatment depends on the cause and may include antiviral medications, antibiotics, or corticosteroids [\[1\]](). In some cases, there may be no specific medicine to treat a particular type of encephalitis, but rest, nutrition, and fluids can help the body fight the infection and alleviate symptoms [\[1\]](). Some patients may require physical, occupational, and speech therapy after the disease is controlled [\[1\]](). ## Prevention of Encephalitis Steps can be taken to help prevent encephalitis caused by infection: - **Good Hygiene:** Regularly washing hands with soap and water [\[1\]](). - **Avoid Sharing Personal Items:** Do not share food, drinks, utensils, or cups with others [\[1\]](). - **Vaccinations:** Get recommended vaccines for viruses that can cause encephalitis [\[1\]](). - **Avoid Mosquito and Tick Bites:** Use insect repellent and wear clothing that covers arms, legs, and feet when in areas where mosquitoes and ticks are present [\[1\]](). You can learn more about the causes, symptoms, and emergency treatments for encephalitis by visiting our comprehensive article on [Encephalitis: Causes, Symptoms, and Urgent Medical Intervention (Arabic)](). ## Medical references - [Encephalitis]() - [Encephalitis]() - [Cerebral spinal fluid (CSF) collection]() General health education; not a substitute for individualized clinical assessment. Citation URL: https://clinicsjo.com/en/faq/is-encephalitis-contagious#answer