FIV Incidence and Facts

Subacute stage

It decreases

CD4+ lymphocytes

CD8+ lymphocytopenia

Terminal stage

PCR diagnostics

No

Prevent secondary infections

Chronic stage

Maintenance of a transient state

FIV incidence is higher in feral cats compared to domestic cats

25%

Sexually intact males

Via a bite and attaches to a receptor on the cell membrane

Replication of the viral RNA

Lymphocytes

It causes a decline in CD4+ cells within the blood

Because they have differing receptors

CD134

FIV replicates extensively within the host cell

Directly from an FIV infection there will be no signs. But secondary infections could cause: Weight loss, Pyrexia, Neurological disease, Oral infections, Enteritis, Respiratory infection, dermatitis

Supportive care and treatment of secondary signs to the infection

PCR diagnostics

No

Help eliminate the reliance on the CD134 receptor hence very difficult to produce a vaccine for.

Terminal stage

Inversion of the ratio

Allows the viral load to increase and brings about the development of diseases caused by secondary infection, neoplasia, and neurological disorders

FIV enters the host cell via a bite and attaches to a receptor on the cell membrane. It then releases viral genes and enzymes into the cell, leading to replication of the viral RNA via reverse transcriptase. The DNA is incorporated into the host nucleus and becomes part of the cell using the host cell machinery. This results in the assembly of viral components in the nucleus, which are then translated into complete viral particles. These particles are released into the host to infect other cells.

FIV preferentially infects lymphocytes, specifically CD4+ T cells. During the acute phase of the infection, the pathogen directly infects and replicates within these cells, leading to a progressive decline of CD4+ cells in the blood. The virus causes a cytopathic effect on the CD4+ cells, resulting in immunosuppression and increased susceptibility to secondary infections.

The development of antiviral drugs for FIV is challenging because the virus undergoes extensive replication and assembly within the host cell, making it difficult to specifically target the viral components. Additionally, FIV exhibits high genetic variability, which can lead to the emergence of drug-resistant strains. Due to these factors, antiviral drugs for FIV often target common viral proteins to increase their effectiveness.

CD134 is the binding site for FIV on the host cell. The virus attaches to CD134 and enters the cell, initiating the replication and assembly process. CD134 plays a crucial role in the initial infection and spread of FIV within the host.

On average, FIV incidence is higher in feral cats, with an average of 4% incidence compared to 1% in domestic cats. In Italy, the incidence in feral cats is even higher, at 25%. This difference is likely due to the increased risk of fighting behavior in sexually intact male feral cats, which leads to a higher prevalence of FIV transmission through bite wounds.

The cytopathic effect of FIV on CD4+ cells refers to the damage caused by the virus to these cells. FIV attacks CD4+ cells over CD8+ cells because they have different receptors. The viral replication within CD4+ cells leads to their destruction, resulting in immunosuppression and the progressive decline of CD4+ cells in the blood.

The main purpose of supportive care in FIV-infected cats is to manage the symptoms and complications associated with the disease. Supportive care includes providing adequate nutrition, managing secondary infections, and addressing any other medical or behavioral issues that may arise. It aims to improve the cat's overall quality of life and minimize the impact of FIV on their health.