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Spring-summer encephalitis:essential data |
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Viral weapon acting on humans |
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Synopsis, Diagnosis, Symptoms,
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Safety Precautions for Spring-Summer Encephalitis Casualties |
Standard Precautions defined by the 1996 CDC guidelines should be adopted for handling patients.Tick control should be practiced.Biosafety level 4 practices should be adopted for handling of samples. |
| Causative organism: (Systematic name in 1997) | Russian spring-summer encephalitis virus |
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| ICTV Acronym | RSSEV |
| Alternative disease names: |
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| Virus classification: | A member of the Tick-borne encephalitis virus complex of the Flaviviridae. Click here for a detailed description of Flaviviruses |
| Vector involvement: | The virus is carried by hard-bodied or Ixodid ticks including Ixodes persulcatus, I. ricinus and I. cookei. |
| Epidemiology of natural outbreaks: | The virus uses ticks and small mammals as a reservoir. Its natural range is Russia and the former Soviet Union, and eastern and central Europe. Each of the tick vectors has a well-defined period of activity through the year and natural outbreaks should coincide with periods of tick activity. |
The disease first appears as a mild influenza-like fever accompanied by leuko- and thrombocytopenia that clears up within a few days. About 30% of patients go on to develop more severe symptoms with meningitis and meningoencephalitis the most significant developments.
Serological methods may be complicated by cross-reaction of antibodies or antisera with other flaviviruses.
Differential DiagnosisOther disease or conditions that need to be eliminated |
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| Other infectious diseases | Other problems |
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Symptoms and effects.
After an incubation period of 4-14 days, the patient develops typical flu-like symptoms (headache, fever) that clear up in about a week. After a remission of a few days to a few weeks, about a quarter of patients develop severe symptoms including meningitis or meningoencephalitis. In severe cases, no more than a quarter of cases, a partial paralysis (paresis) may be seen. This disease is very similar to tick-borne encephalitis, but it is much more sever with a fatality rate of 25%.
Medical and Physical Countermeasures.
Vaccination (Immunoprophylaxis)
A vaccine of killed virus that is effective against tick-borne encephalitis that also offers protection to this disease is available in Europe and is an investigative new drug in the United States.
Specific Therapy
No specific therapies are available.
Supportive care
The virus is killed by many disinfectants, including 1% sodium hypochlorite, 2% glutaraldehyde, formaldehyde, and 70% ethanol. It is killed by heating at 60°C for 10 minutes.
Agent Properties and Potential Uses
The virus is widespread in Russia and Eastern Europe where it is normally spread by the bite of ticks of the genus Ixodes. In addition, it can be spread through contaminated milk.
The virus is dependent upon its tick host for survival and tick control using repellents and insecticides such as permethrin should be able to blunt an attack once it is identified.
Terrorist Acquisition and Attempted Use.
| Disease | ICD-9-CM | ICD-10 |
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| Tick-borne encephalitis | 063 | A84 |
| Far Eastern encephalitis | 063.0 | A84.0 |
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