Coltivirus - Classification, Transmission, Morphology, Genome, Lab diagnosis, Colorado tick fever

Classification of Coltivirus

The Coltivirus is phenotypically classified as:

Realm: Riboviria

Kingdom: Orthornavirae

Phylum: Duplornaviricota

Class: Resentoviricetes

Order: Reovirales

Family: Reoviridae

Subfamily: Spinareovirinae

Genus: Coltivirus

There are five species in this Coltivirus genera:

• Colorado tick fever coltivirus

• Eyach coltivirus

• Kundal coltivirus

• Tai Forest coltivirus

• Tarumizu coltivirus

Transmission of Coltivirus

Coltivirus is transmitted via tick bite. It is associated with diseases such as:

• Colorado tick fever

• Salman river virus

• Beijing virus

• Gansu virus

• Eyach virus

Morphology of Coltivirus

Morphologically, Coltivirus has icosahedral symmetry, is non-enveloped, and contains 12 segments of dsRNA.

Genome of Coltivirus

The genome of Coltivirus has a size of 70-80 nm in diameter and has two layered capsids (VP2 and VP5- outer layered).

The VP2 and VP5 are attached to VP7. It has an inner layer (core particle) with 260 trimers of VP7 arranged in a ring-like structure. VP7 is associated with a sub-core-shell composed of 120 copies of VP3 while VP3 surrounds transcriptase complex (VP1, VP4, and VP6) and genomic RNA segments.

Clinical Manifestation of Coltivirus

A major clinical manifestation of Coltivirus is the Colorado tick fever virus.

Colorado tick fever virus

Colorado tick fever virus is an acute viral fever transmitted by the bite of a wood tick. The Coltivirus replicates in erythroid precursor cells without severely damaging them and is present in mature RBC for RBC’s life (120 days).

The incubation period is around 3-6 days and it causes non-specific febrile illness. The sudden onset of fever, chills, headache, malaise, nausea, and vomiting are the symptoms of the Colorado tick fever virus.

The fever is biphasic- two episodes of fever. Complications are rare but include hepatitis, pericarditis, encephalitis, aseptic meningitis, atypical pneumonia, epididymo- orchitis. Single infections produce life-long immunity and are self-limiting in nature.

Lab diagnosis of Coltivirus

The laboratory diagnosis of Coltivirus begins with the collection of samples/specimens.

Sample

The common samples/specimens collected include:

• blood

• CSF

Isolation/Culture

Like most viruses, the culture and isolation of Coltivirus can be done via animal inoculation, as well as cell lines.

Serodiagnosis

The serodiagnosis of Coltivirus can be performed by the following methods:

• IFA (Indirect Fluorescent Antibody) Assay

• EIA (Enzyme Immuno Assay)

• Neutralization test

• A 4-fold rise in acute and convalescent sera

Treatment of Coltivirus

No treatment has been available for Coltivirus infection.