Feline rhinotracheitis virus (Feline herpesvirus type 1 -- FHV-1)

Test code: S0105 - Ultrasensitive qualitative detection of Feline herpesvirus type 1 (FHV-1) by real time polymerase chain reaction

S0105 is included on P0020 - Feline Respiratory Panel

Feline rhinotracheitis virus (also known as feline herpesvirus type 1 or FHV-1) causes an acute respiratory illness of cats known as rhinotracheitis. The virus has a worldwide distribution and affects both domestic and wild cats.

Infected cats develop respiratory symptoms -- sneezing, nasal discharge, rhinitis (inflammation of the nose), and conjunctivitis (inflammation of the membrane lining the eyelid). The virus also affects the reproductive tract and can cause complications during pregnancy. Rhinotracheitis is part of the feline upper respiratory infection complex, which is a group of viral and bacterial infections (e.g., calicivirus, chlamydiosis) that cause sneezing and discharge from the eyes and nose. Cats often have two or more of these upper respiratory infections at the same time, and FHV-1 is one of the most common.

FHV-1 can be shed through the discharge from an infected cat's eyes, nose and mouth, and direct contact with these secretions is a common mode of transmission. Several days of close contact may be necessary for infection to occur. Another common mode of transmission is contact with contaminated objects that an infected cat has touched or sneezed on, such as cages, food and water bowls, litter trays and the pet owner's clothing and hands.

The major problem with this infection is that many infected cats never completely get rid of the FHV-1 virus and become latent carriers. Although they may not show symptoms, their neurons harbor the virus; they can intermittently spread the infection and are a major source of new infections.

Diagnosis of FHV-1 infection is difficult by traditional means because clinical symptoms of FHV-1 are nearly indistinguishable from the other major feline respiratory pathogens, feline calicivirus and Chlamydia psittaci. Because of the time-consuming and expensive nature of most previous diagnostic methods, inaccurate empirical diagnoses were often made, and these have often resulted in inappropriate treatment of the disease. Traditional diagnostic techniques include isolation of FHV-1 from nasal exudates, conjunctival or oropharyngeal swabs following inoculation of cell cultures, and fluorescent antibody on smear preparations of affected tissues. The commonly used serological testing requires acute and convalescent phase samples taken 1 to 2 weeks apart. The disadvantages of serological testing include the difficulty in taking sufficient quantities of blood from affected kittens, the length of time required to reach a diagnosis and the low antibody titer in convalescent cats and latent carriers.

Molecular detection by PCR avoids many of the disadvantages of these other methods; PCR detection of FHV-1is rapid, highly sensitive and very specific.

Utilities:

• Confirm the disease causing agent
• Shorten the time required to confirm a clinical diagnosis of Feline herpesvirus type 1 infection
• Ensure that animal groups are free of FHV1
• Early prevention of spread of FHV1 between animals
• Minimize human exposure to FHV1
• Safety monitoring of biological products that derive from susceptible animals

Specimen requirement: Nasopharyngeal, conjunctival or oral swab, or 0.5 ml whole blood in EDTA (purple top) or ACD (yellow top) tube, shipped overnight at room temperature.

For specimen types other than those listed here, please call to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Qualitative real time PCR

Normal range: Nondetected