Japanese encephalitis is a relatively harmless viral disease transmitted by mosquitoes. It occurs mainly in the Far East, where about 40,000 cases are recorded each year. How is Japanese encephalitis manifested and how is it treated?

Japanese encephalitisis an infectious disease typical of the Far East and Southeast Asia. It was first described in the 1870s. The epidemics of Japanese encephalitis appear every 10 years, and the largest one broke out in 1924 and caused over 6,000 deaths. illnesses. In 1998, two people died from the disease in northern Australia. Cases occur in India, Nepal, Sri Lanka, Papua New Guinea and Pakistan, as well as in China, Japan, Cambodia and Malaysia.

Japanese encephalitis is caused by a neurotrophic virus belonging to theFlaviviridaefamily (which also includes dengue, yellow fever, West Nile fever, or our native tick-borne encephalitis) to arboviruses carried by mosquitoes of the genusCulexandAedese.g.Aedes japonicus . Every year from 30,000 to 50,000 are ill. people, mostly children under the age of 15 and mainly from rural areas - the disease is rather absent in cities. Tourists are also at risk, and here without age restrictions. The incubation period of the disease ranges from 6 to 16 days.

Symptoms of Japanese encephalitis

In the vast majority of cases - over 95% - Japanese encephalitis is asymptomatic or mild, flu-like symptoms, such as:

  • depressed mood
  • fever
  • headache
  • gastrointestinal disorders - especially in children
  • poly-like syndrome
  • pain when urinating (dysuria)
  • nausea
  • vomiting
  • pronunciation problems

After about 10 days, the fever subsides and the disease regresses.

In a few percent of patients the symptoms are severe, affecting the central nervous system, such as encephalitis, meningeal symptoms, paresis, disturbance of consciousness. Approx. 30% of these cases end with serious complications such as:

  • ataxia, dystonia (clumsiness, movementsinvoluntary flexing the body)
  • muscle weakness
  • parkinsonism (mask face, tremors, extremely increased muscle tension)
  • dementia or mental disorders
  • and even death - which is influenced by a number of factors, such as other diseases of the patient or even age.

Diagnosis and treatment of Japanese encephalitis

The diagnosis of this disease is based on a history and blood tests for the presence of specific IgM and IgG antibodies , with the concentration of IgM antibodies to the Japanese encephalitis virus increasing at the beginning of the disease and after a week they are detectable in over 65% of patients. The detection of IgM antibodies or a 4-fold increase in the concentration of IgG antibodies indicates a recent infection with the Japanese encephalitis virus. In addition, it also checks whether there is leukocytosis.

The doctor may also order an MRI of the head, which shows bilateral involvement of the thalamus and the brain stem in the sick person. Treatment of Japanese encephalitis is actually symptomatic only, although it usually wears off on its own without any intervention. The patient is given antipyretic and anti-inflammatory drugs, and appropriate hydration and rest are recommended. However, there is a vaccine against the disease, which is taken in three doses, and that should be considered by those traveling to areas with Japanese encephalitis. Avoiding mosquito bites as much as possible helps to protect yourself from getting sick. There should be mosquito nets in the windows, you need to remember about appropriate clothing (long sleeves, legs, and repellants.

Important

Japanese encephalitis cannot be caught by humans, but there is a risk of the disease passing on to the fetus, and then even miscarriage. The main hosts and carriers of this pathogen are birds (e.g. herons), as well as reptiles and bats. Humans become infected primarily from pigs and horses - via mosquitoes. Vaccinating pets significantly reduces the number of cases.

Category:

Infectious diseases