Team:Moscow City/EHV

There is currently no vaccine that fully protects against all the effects of herpes viruses. The methods were invented a long time ago and are outdated. Moreover, from the nervous form, it does not exist at all.

Individual care

Like individual drinkers, feeders, care products, transport

Balanced nutrition

Boost immune system

Isolation

The only reliable way to prevent an outbreak is to spread the virus. Everything that the sick horse touched must be cleaned.

Let’s start with detection

1. What about the detection?
2. Pcr, antibody or CRISPR-Cas methods will provide fruitful results. Why?

The fact that this is a herpes virus disease is difficult to distinguish by symptoms.
● First, do not confuse it with the symptoms of other diseases: allergies, flu, arthritis, horse fatigue.
● Secondly, EHV is characterized by the manifestation of clinical signs already at a late stage, in which case treatment should begin promptly and correctly.
● Therefore, timely diagnosis and treatment are important for the survival of horses.

What diseases does the herpes virus cause?

The clinical signs depend on the type of virus. There are 5 of them in total, but 1 and 4 pose the greatest threat. They lead to disruption of the work of three organ systems at once [6].

How does it spread?

Equine herpesvirus is the most contagious equine virus. The presence of just one carrier horse is enough to infect up to 80% of the rest-this has been repeatedly reported to us by the owners of large stables.

It is transmitted in many ways:

through shared drinkers, feeders, buckets, and horse-hauling vehicles.
puddles and ponds
discharge from the nose and mouth that spreads in the wind or remains on the person's clothing.
direct contact of horses through sneezing or snorting
spreading from mother to fetus
from an aborted fetus)

Affected horses should be identified in advance and isolated as soon as possible.
The only viable way to prevent the spread that has already begun is complete premature isolation. Everything that could get the saliva or other fluids of the horse should be disinfected[7].

Why prevention is not enough?

EHV is feared. When they hear that has appeared in a neighboring stable, horse owners immediately try to minimize all contact with this stable and carry out preventive measures on their own: vitamins, a closer analysis of the horse's health. There were cases when they refused to come to rhinopneumonia calls, fearing to spread them to other locals.

The issue of vaccines is ambiguous.

There is currently no vaccine that fully protects against all the effects of herpes viruses. Moreover, from the nervous form, it does not exist at all.
A vaccinated horse will tolerate diseases more easily, but there is a high risk of becoming a carrier and still having an outbreak.
We talked to Russian veterinarians. Opinions about vaccines are very divided.
In Russia, the vaccine against the abortive form of EHV-1 was invented by K. P. Yurov. This is a promising vaccine, but it also does not give complete protection [8].

The creation of a vaccine is the next stage in the development of our project.

Why is it even essential to perform diagnostics using PCR, antibody, or Crispr-Cas methods?

The fact that this is a herpes virus disease is difficult to distinguish by symptoms.

First, do not confuse it with the symptoms of other diseases: allergies, flu, arthritis, horse fatigue.
Secondly, nervous forms of the virus are characterized by the manifestation of clinical signs already at a late stage, in which case treatment should begin promptly and correctly.
The appearance of a nervous form in at least one horse can be stale for 50% of horses[9] .
Therefore, timely diagnosis and treatment are important for the survival of horses.

Why is it even essential to perform diagnostics using PCR, antibody, or Crispr-Cas methods?

Three days or month (the average time from calling a doctor to getting a result) can be crucial for a horse.

Especially for cases of the nervous form: the symptoms do not appear at first, and then the horse's condition worsens sharply. Even experienced veterinarians can not always accurately diagnose the nervous form of the disease. More often, it is already determined as the cause of death at the autopsy of the animal.

How are tests done now?

Call a doctor -> inform your local vet clinics about the virus threat and get a referral for a test. The stable is quarantined. Suspected horses are isolated -> take a nasal swab or blood sample - > send it to the lab - > wait for the result - > extend the quarantine to the stable if the result is positive.

1 - Outbreaks connected with EHV in Valencia https://inside.fei.org/fei/ehv-1
2 - the USA https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8231618/
3 - Major 2009 Outbreak in Normandy and Europe https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6832873/
4 - Poland https://bmcvetres.biomedcentral.com/articles/10.1186/s12917-020-02586-y
5 - EHV-1 and EHV-4 in the UK https://www.gov.gg/CHttpHandler.ashx?id=123053&p=0
6 - EHV-1 A Constant Threat to the Horse Industry doi: 10.3389/fmicb.2019.02668
7 - EHV FAQ https://www.bhs.org.uk/advice-and-information/horse-health-and-sickness/equine-herpes-virus
8 - Laboratory control results of inactivated vaccine immunogenicity against rhinopneumonia and salmonella equine abortion https://doi.org/10.3103/S106836741605013X
9 -- Characterization of high virulent strains of equine rhinopneumonitis virus https://doi.org/10.1088/1755-1315/548/4/042041