Powassan virus: Difference between revisions
From IDWiki
(→) |
No edit summary |
||
| (One intermediate revision by the same user not shown) | |||
| Line 11: | Line 11: | ||
* Transmitted by a number of ''Ixodes'' and ''Dermacentor'' ticks |
* Transmitted by a number of ''Ixodes'' and ''Dermacentor'' ticks |
||
** ''[[Ixodes cookei]]'', ''[[Ixodes scapularis]]'', ''[[Ixodes marxi]]'', ''[[Ixodes spinipalpus]]'', ''[[Dermacentor andersoni]]'', and ''[[Dermacentor variabilis]]'' |
** ''[[Ixodes cookei]]'', ''[[Ixodes scapularis]]'', ''[[Ixodes marxi]]'', ''[[Ixodes spinipalpus]]'', ''[[Dermacentor andersoni]]'', and ''[[Dermacentor variabilis]]'' |
||
* Transmission only requires 15 minutes of tick attachment |
|||
== Clinical Manifestations == |
== Clinical Manifestations == |
||
| Line 18: | Line 19: | ||
== Diagnosis == |
== Diagnosis == |
||
* |
* Serology with hemagglutination assay (HI) for IgM + IgG |
||
**Fourfold or greater increase or decrease in titre between the acute phase and convalescent phase serum is considered to be diagnostic |
|||
**Cross-reacts with other flaviviruses, including [[dengue]] |
|||
*Molecular testing available at NML |
*Molecular testing available at NML |
||
Latest revision as of 16:26, 8 July 2023
- Tick-borne viral infection that can cause encephalitis
- Closely related to deer tick virus
- Named for Pawassan, Ontario, but endemic in Eurasia and North America
Background
Microbiology
- Single-stranded positive-sense RNA virus in the genus Flavivirus, family Flaviviridae
- Two genotypes: lineage 1 and lineage 2
Epidemiology
- Transmitted by a number of Ixodes and Dermacentor ticks
- Transmission only requires 15 minutes of tick attachment
Clinical Manifestations
- Incubation period 1 to 3 weeks
- Fever, headache, confusion, weakness, encephalopathy, focal neurological deficits, and vomiting
- Progresses to severe encephalitis
Diagnosis
- Serology with hemagglutination assay (HI) for IgM + IgG
- Fourfold or greater increase or decrease in titre between the acute phase and convalescent phase serum is considered to be diagnostic
- Cross-reacts with other flaviviruses, including dengue
- Molecular testing available at NML
Management
- Supportive
Prognosis
- Mortality is 10%, with survivors having permanent neurologic sequelae
