[Veterinarian-authored] Cats, Ticks, and SFTS: Transmission, Symptoms, Human Risk, and Prevention

Recently, news outlets have been reporting on SFTS, a disease transmitted by ticks. It not only infects dogs and cats but also humans, and has a high mortality rate. In this article, we will explain SFTS.

What is SFTS? A viral infection that can infect both humans and cats.

What is SFTS (Severe Fever with Thrombocytopenia Syndrome)?

SFTS stands for "Severe Fever with Thrombocytopenia Syndrome," and is also known as Severe Fever with Thrombocytopenia Syndrome.

The first human case was reported in China in 2011, and in Japan in 2013. In dogs and cats, cases of SFTS were confirmed in 2017, and the number of cases has been increasing since then.

The virus is transmitted by ticks.

SFTS is caused by a virus and is transmitted by ticks. It was originally thought that animals were infected without symptoms (asymptomatic infection).It has been found that cats can also be infected by tick bites.

It is a zoonotic disease, and there have been cases of transmission from cats to humans.

SFTS is an infectious disease transmitted by ticks, and it is believed that cats can become infected by tick bites. Humans are also known to be infected by ticks in the same way.

The scary thing about SFTS is that it can be transmitted through contact with the blood or body fluids of an infected cat. Human-to-human transmission has also been reported.

Cases have been reported in Japan.

The first human case was reported in China in 2011, and it was confirmed in Japan in 2013. Cases in cats were reported in 2017 and have been increasing every year. While cases have been confirmed in a wide area of western Japan, they are gradually being confirmed in eastern Japan as well. As of 2024, 977 cases have been confirmed nationwide.

Main symptoms when cats are infected with SFTS

High fever, vomiting, diarrhea, lethargy, etc.

In cats, symptoms include decreased vitality and appetite, fever above 39°C, leukopenia, thrombocytopenia, jaundice, vomiting, and diarrhea. The mortality rate is also high, over 60%, and the condition deteriorates rapidly, often leading to death within a few days of onset.

No specific treatment, supportive care is the mainstay of treatment.

Currently, there is no specific treatment, and only supportive care is available. Subcutaneous or intravenous fluids are administered, and antibiotics are used to prevent secondary infections. If vomiting occurs, antiemetics are used.

High mortality rate, early intervention required.

SFTS in cats progresses rapidly, with death often occurring within about 5 days of onset. The mortality rate is also high, exceeding 60%. There is a risk of transmission to humans and other animals if they come into contact with the bodily fluids of an infected cat or are bitten by one. Therefore, isolation is necessary. While early treatment does not necessarily lead to improvement, early intervention is necessary to prevent the spread of infection.

Can SFTS be transmitted from cats to humans?

Risk of infection through bites, scratches, body fluids, and blood

There have been cases of infection through contact with infected cats. It is believed that infection can occur through being bitten or scratched by an infected cat, or by touching its vomit, excrement, or blood. In fact, in a case in Mie Prefecture, it was observed that a veterinarian who examined an infected cat did not have any tick bites, and it is thought that the infection occurred during the examination. In other cases, infection occurred after being bitten by an infected cat.

Caution is required when in contact with infected cats (veterinarians also warned)

Contact with infected cats increases the risk of infection. Therefore, infected cats need to be isolated. Never touch an infected cat with bare hands. If any procedure is necessary, the National Institute of Infectious Diseases has issued guidelines to wear a mask, goggles, and gloves.

Since infections have occurred among veterinary staff at animal hospitals, infection prevention measures have been presented for veterinary staff to wear face shields, goggles, gowns, and masks when examining patients.

What you can do to prevent SFTS

Administer tick preventative medication to cats regularly (recommended year-round)

Ticks inhabit grassy areas and become active from early spring to autumn when the average temperature exceeds 14℃. Ticks transfer to animals and people when they approach. Since SFTS is transmitted by tick bites, it is necessary to prevent ticks from biting. This is where tick preventative medication comes in.

If tick preventative medicine is administered regularly, ticks can be killed before they bite, even if they attach to the skin. Ticks become active when the average temperature is above 14℃, but in recent years, due to global warming and improved living environments, winters have become warmer. As a result, the risk of tick infection is high all year round. Not only outdoor cats but also indoor-only cats have been confirmed to be infected with ticks. Year-round tick control is required.

Outdoor cats are particularly at high risk.

Outdoor cats often enter grassy areas. Ticks inhabit grassy areas and wait for opportunities to transfer to cats. There is no doubt that outdoor cats are very likely to pick up ticks.

Owners should also wear long sleeves and long pants when entering fields and grassy areas to prevent bites.

There is no doubt that ticks lurk in fields and grassy areas. The Ministry of Health, Labour and Welfare's website states that to prevent tick bites, you should wear long sleeves and long pants to avoid exposing your skin.

It is also a good idea to use tick repellents.

If an infection is suspected, take the cat to the vet immediately and minimize human contact.

If a cat is infected with SFTS and develops symptoms, the progression is very rapid. Cats often die within about 5 days of developing symptoms. Therefore, if you notice anything unusual, take your cat to the vet immediately. In addition, it is known that SFTS can be transmitted from infected cats to humans.

If your cat shows symptoms suspected of SFTS, or if you need to handle a sick stray cat, wear gloves, an apron, and a mask, and try to have as few people as possible handle the cat. Do not hug the cat, and minimize contact.

FAQs: Is an indoor cat safe from SFTS? Is there a vaccine?

Even indoor-only cats may not be completely safe from ticks carried in on human clothing.

Even indoor cats can get ticks. Since ticks live outdoors, they can be brought indoors on people's clothes, shoes, or bags, and then bite the cat. Therefore, it cannot be said that there is no risk.

Vaccine currently undeveloped.

A vaccine for the SFTS virus has not yet been developed, and a cure has not been established. While treatments are being considered for humans, they have not yet been applied to cats. Therefore, it is important to avoid tick bites.

Risk management for multi-cat households and households with dogs

If you have multiple cats or dogs, assume the risk is even higher. Dogs go for walks outside, where they can pick up ticks in grassy areas. From there, the dog can become infected, and there is a possibility of transmitting ticks or bodily fluids to cohabiting animals. Also, if you have multiple cats and one of them goes outside and gets bitten by a tick, there is a very high chance that the other cats will also become infected. You need to be even more aware of the risks.

Summary

SFTS not only infects cats but also humans, and has a very high mortality rate. The mortality rate in cats, in particular, is as high as 60%. To avoid contracting SFTS, it is important to prevent tick bites. In addition to keeping cats strictly indoors, both outdoor and indoor cats should receive regular tick prevention. And if you suspect any symptoms, visit an animal hospital wearing gloves.

▼Here are the cautionary materials distributed at the animal hospital where the author is the director.