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After floods, Kerala to combat deadly Rat-Bite Fever. What is this Rat Fever?

Rat Bite Fever

According to the Directorate of Health Services (DHS), between August 1 and September 2, 10 people were confirmed to have died from rat fever, a bacterial disease that spreads through water or soil contaminated by infected animals.

Suspected cases: 719

Confirmed cases: 302

Suspected deaths: 46

Confirmed deaths: 10

What is Rat-Bite Fever?

Rat bite fever is a zoonotic disease, that is it is transmitted from animals to people It is caused by bacteria and transmitted by rodents.

Well, it is of two types:

Streptobacillus, caused by streptobacillus moniliformis

Spirillosis, caused by spirillum minus.

In the United States, the most common form of the illness is caused by Streptobacillus moniliformis. The latter is commonly found in Asia. And hence the one that has hit Kerala is Spirillosis, transmitted by the Gram-negative coiled rod bacterium. While the illness carries a mortality rate of 13 percent if left untreated, its symptoms are nonspecific, which may prevent an early diagnosis. This condition is also known as a spirillary fever, streptobacillus, streptobacillary fever, or sudoku, depending on the region of the world where it is diagnosed and which bacterium is responsible.

You thought Rat Fever is something new!

History of the Disease

Rat-bite fever was first described in India more than 2,300 years ago. It was first reported in the U.S. in 1839. In North America, Streptobacillus moniliformis has been known to infect laboratory technicians and the poor. Since rats have become popular pets, children now account for more than 50 percent of cases in the U.S.

How does Rat Fever Spread?

Spirillum minus and Streptobacillus moniliformis are both transmissible from rats or mice to people, but not from person to person, so someone who has this disease is not at risk of passing it on to someone else. Several people get a rat-bite fever when they come in contact with urine or mucociliary secretions either from the eyes, nose or mouth of an infected animal. Rat bite fever mostly occurs through a bite, but in some cases, it may occur quickly through contact with such secretions. It may occur through consumption of contaminated water or food by rat’s urine or feces. The primary source of infection is a rat. Other animals that may cause this disease include squirrels, gerbils or weasels. Furthermore, pets like cats or dogs can transmit this disease to humans if they are in contact with these infected animals.

Signs and Symptoms

Streptobacillary RBF Symptoms

• Fever

• Vomiting

• Headache

• Muscle pain

• Joint pain

• Rash

Symptoms usually occur 3-10 days after exposure to an infected rodent, but can be delayed as long as 3 weeks. By this time, any associated bite or scratch wound has usually healed. Within 2-4 days after fever onset, a maculopapular rash may appear on the hands and feet. This rash is identified by flat, reddened areas with small bumps. One or more joints may then become swollen, red, or painful. redd

Spirillary RBF (also known as Sodoku) Symptoms

Symptoms can vary and often include:

• Fever (that may occur repeatedly)
• Development of an ulcer at the bite wound (when applicable)
• Swelling near the wound
• Swollen lymph nodes
• Rash (occurs following partial healing of the wound)

These symptoms usually occur 7-21 days after exposure to an infected rodent.

How can you know and be sure it is it?

Rat bite fever diagnosis is made by detecting the bacteria either in blood, skin, joints fluid or lymph nodes. Diagnosis of rat bite fever caused by Streptobacillus is made by collecting a blood sample or a fluid sample from a joint, which is then cultured to permit their growth. Microscopic Examination allows the identification of Streptobacillus moniliformis bacteria. It appears as a gram-negative, pleomorphic bacillus in chains or clumps with irregular lateral swellings. Diagnosis of rat-bite fever caused by Spirillum minus is confirmed by a blood sample or tissue sample from the site of the wound by culture or by direct visualization. PCR can also be used to identify the bacteria.

What can you do if you or a closed one gets a Rat Fever?

If you have any symptoms of rat-bite fever after exposure to rats or other rodents, please immediately contact your health care provider. Be sure to tell your provider of your exposure to rodents. If you have RBF, your doctor can give you antibiotics that are highly effective at curing the disease. d Penicillin is the antibiotic most often used. If you are allergic to penicillin, Tetracycline or erythromycin are given an alternative.

However, Without treatment, RBF can be serious or potentially fatal. Severe illnesses can include:

• Infections involving the heart (endocarditis, myocarditis, or pericarditis)

• Infections involving the brain (meningitis)

• Infections involving the lungs (pneumonia)

• Abscesses in internal organs

The following measures of prevention can be followed to minimize the risk of its spread:

• Minimize the contact with rodents.

• Proper washing of face and hands should be done if in contact.

• Clean the scratches and apply antiseptics.

• There are no available vaccines in the market for this disease.

• Mostly Animal handlers, sanitation, sewer workers and laboratory handlers are exposed to this disease so they should be advised for special precautions.

• Avoid touching rodents whether alive or dead.

• Pets should not be permitted to feed on rodents.

• People residing in areas with sanitation issues and overcrowding are more prone to catch the Rat-bite fever. It is a difficult task for people residing in rat-infested buildings to shift from such places.

• Streptobacillary type of fever can occur quickly after consumption of contaminated milk or dirty water, so it’s advised to drink pasteurized and milk and drink properly boiled water.