Rat Bite Fever – Symptoms, Causes, and Treatments

Rats are a common nuisance around the world. They’re not like Remi from Ratatouille cooking up a fine five-course meal or Stuart from Stuart little running around and having a merry time with the family.

On the contrary, their chewing and burrowing can cause damage to property and vegetation. And let’s not forget that they also transmit harmful infections to humans, and Rat Bite Fever is one such disease.

This article explains  the diseases that can result from a rat bite, how to treat the wound, and any issues.

What is Rat Bite Fever (RBF)?

Streptobacillus moniliformis or Spirillum minus bacteria causes Rat Bite Fever, a severe infection. Rat bites, contact with rat urine and excrement, and contaminated foods and drinks are all ways for these diseases to spread to humans.

“Annually, over 2 million animal bites occur in the United States, and rats are responsible for around 1% of bites,” researchers write in a study published by PubMed Central.

Rat Bite Fever (RBF) is more likely to develop in children under five who live in poverty.

People who work with rats in pet stores and labs are also in danger, and the probability of infection from a bite is about 10%.

Rat bite infections

Infection is common after a rat bite. If any of these symptoms appear in the hours and days following a bite, the wound may be infected and shows signs of

• Redness
• Swelling
• Heat
• Pus at the wound site

When should you see a doctor?

If a rat has bitten you, see your doctor right away, and you may require tetanus vaccinations or sutures.

 Because of the potential of scarring and loss of function, wounds on the face or hands should always be checked by a doctor.

RBF, if left untreated, can lead to serious, even life-threatening complications. If you have any strange symptoms after being bitten by a rat, seek medical help.

S. moniliformis is diagnosed by obtaining a sample of blood or tissue for testing. The findings are typically received within three days, though this can vary.

A doctor collects a tissue sample for testing to identify S. minus. A stain is applied to the tissue before placing it on a glass slide. This slide is examined by a laboratory technician, who can identify the bacteria based on their size, shape, and colour.

Types of Rat Bite Fever?

The significant risk with rat bites is that you will contract Rat Bite Fever, a bacterial infection (RBF). If a human is bitten or scratched by an infected rat, they can get the disease.

According to the Centre for disease control and prevention, it’s also possible to get the disease by petting or handling an infected animal.

The following are the two bacteria that cause RBF:

• Streptobacillus moniliformis (S. moniliformis) (In the United States, it’s the most common.)
• Spirillum minus (Spirillum minus) (In Asia, it’s most common)

The signs and symptoms of infection caused by each bacteria vary slightly. The good news is that an antibiotic can effectively treat rat-bite fever, and Rat Bite Fever can be lethal if left untreated.

Streptobacillus Rat Bite Fever

According to the Center for Disease Control and Prevention, S. moniliformis infections can lead to abscesses, which are pockets of infected fluid in your belly or other parts of your body. The infection could also cause liver hepatitis, meningitis, pneumonia, nephritis, and kidney ailment.

Approximately 10% of those infected with S. moniliformis die due to the infection.

Spirillum Rat Bite Fever

It causes a purple or reddish rash that can be fatal if the infection spreads to the heart, brain, lungs, or other internal organs.

Haverhill Fever

Haverhill fever is another type of Rat Bite Fever. People can get this infection if they eat contaminated food or drink contaminated fluids. Severe vomiting and a sore throat are possible symptoms.

First aid for a rat bite or scratch

Following a rat bite, you can and should take the following steps

Take basic precautions

If you aren’t the patient, use standard precautions and, if available, wear personal protection equipment when assisting the individual who has been bitten.

Clean the wound

Stop the bleeding and clean the area with warm water and soap. Clean the wound from the inside out. Then, make sure to rinse away all of the soap, or else it will irritate your skin later.

Dress the wound

Apply a clean, dry dressing to the wound. Before covering the wound, apply antibiotic ointment to it.

Remove unnecessary accessories

If the wound is on a finger, remove any rings from it if it swells.

Ask a doctor

After the bite, try to catch the rodent. Doctors will be able to analyse it later to see if the animal has an infection.

Symptoms of Rat Bite Fever

The symptoms of RBF vary based on the bacterial infection that has caused it, and RBF can have early symptoms similar to those of other medical conditions.

According to PubMed Central, the incubation time for S. moniliformis is 3–20 days. Before the symptoms of spirillary RBF develop, the bite may begin to heal, and it may take 1–3 weeks for symptoms to appear.

Streptobacillus Rat Bite Fever

Keep an eye out for the following signs and symptoms, and get medical assistance immediately

• Fever
• Headaches
• Vomiting
• Back and joint pain
• Rash on the hands and feet, often with inflamed joints.

Rat Bite Fever symptoms typically present three to ten days after exposure or bite, but they might appear three weeks later. A rash emerges two to four days after the fever has passed.

Don’t assume you’re safe just because the bite or scratch appears to be getting better. The illness may still be present in your body, and a fever may not occur until the wound has healed.

According to the Center for Disease Control and Prevention, S. moniliformis infections can lead to abscesses, which are pockets of infected fluid in your belly or other parts of your body. The condition could also cause liver hepatitis, meningitis, pneumonia, nephritis, and kidney ailment.

Spirillary Rat Bite Fever

The symptoms usually appear one to three weeks following exposure to an infected rat. They differ from streptobacillus RBF in that they can include

• Fever that may disappear and return
• There is irritation and a possibility of an ulcer at the bite wound.
• Lymph nodes swollen
• Swelling at the wound’s site

Causes of Rat Bite Fever

RBF can be divided into two categories. The most prevalent type in North America is streptobacillary RBF, caused by S. moniliformis infection.

Spirillary RBF, also known as sodoku, is the other form. S. minus bacteria cause it, which is the most common kind in Asia.

After one of these bacteria enters the body through an open wound or the mucous membranes of the eyes, nose, or mouth, a person develops RBF.

Bacteria cause RBF. It can spread if someone gets

• Bitten by infected rodents or scratched by infected rodents
• Infected rodents’ saliva, urine, or faeces come into touch with contaminated surfaces.
• Contaminated foods or beverages

Even though RBF has been reported worldwide, it remains a relatively uncommon condition.

However, a person’s risk of RBF may be increased if they

• As part of their job, they have to deal with rats
• Rats and other rodents are kept as pets
• Reside in an infested building or area

RBF is not passed from person to person.

Treatments for Rat Bite Fever

You should always consult a doctor for RBF. RBF, if left untreated, can lead to severe complications and even death. Your doctor will prescribe antibiotics, and they will most likely include

• Amoxicillin
• Penicillin
• Erythromycin
• Doxycycline

Patients with a severe rat-bite fever that affects the heart may be prescribed high-dose penicillin and antibiotics gentamicin or streptomycin.

Risk Factors of Rat Bite Fever

Exposure to rats or other rodents is the most significant risk factor for Rat Bite Fever. Rat Bite Fever is not contagious and does not spread from person to person, and it can only be contracted from an infected animal.

Rat Bite Fever is more common in the following people

• People who keep rats or other rodents as pets.
• Those who keep rats or other rodents to feed them to other animals
• People who operate in settings where rats or other rodents are present, such as research laboratories or pet stores
• People live in places where there are large concentrations of wild rats or mice.
• Older adults
• Pregnant women
• Immune-compromised individuals
• It is more common in young children than adults. This is because their immune systems are still in the early stages of development.

Prevention of Rat Bite Fever

Avoiding direct contact with rats, places with rodent infestations and other areas where rodents may be present reduces your chance of contracting RBF and other rodent infections.

If you have rats as pets at home or breed them as feed for other animals

• After coming into contact with rats or mice, wash your hands with soap and water.
• Assist children in washing their hands. Handwashing thoroughly lowers the likelihood of disease transmission to humans.
• Small mammal bites and scratches should be prevented since they can become infectious.
• Even though they appear friendly, small mammals should be approached with caution, especially those sleeping.
• To keep your pets healthy and prevent infectious infections, see your veterinarian regularly for examination and treatment.

If you work at a pet store with rats

• Wear protective clothing such as gloves and masks.
• After handling rodents, avoid touching your mouth and face.
• After handling rats, their cages, bedding, urine, or droppings, wash your hands with soap and warm water for at least 20 seconds.

If you’re working with rats in a lab or for animal research

• Make sure you wear the required lab gear, including gloves, and take the necessary safety precautions.
• After handling rodents, avoid touching your mouth and face.
• Hands should be washed with soap and warm water for at least 20 seconds after handling rodents.

What happens if you don’t treat a rat bite?

If left untreated, rat bites can lead to significant health problems. Inflammation of the heart muscle, valves, arteries, and veins leads to necrosis, myocarditis, endocarditis, pneumonia, systemic vasculitis, pericarditis, polyarteritis nodosa, hepatitis nephritis, meningitis, localised abscesses, and amnionitis, are some of the conditions that can occur.

If left untreated, however, the mortality rate is only 10%.

Conclusion

S. moniliformis and S. minus bacteria cause RBF. Humans are exposed to these bacteria through rodent bites and contaminated food or drinks.

Fever, joint pain, and nausea are common nonspecific symptoms of RBF. RBF, if left untreated, can develop into severe consequences such as endocarditis or inflammation of the heart’s membrane.

Antibiotics are used to treat RBF. Even if they’re no longer sick, people must finish their antibiotic course, and this can aid in the prevention of recurrent infections as well as drug resistance.

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