Overview of mouse bite disease - Sodoku

The following article is the most basic knowledge about mouse bite disease - also called Sodoku disease, invite you to watch.

What is mouse bite?

Mouse bite fever is a rare disease, known for its characteristic appearance depending on the region of the world. Although most patients exhibit mild symptoms and respond well to common antibiotics, it can lead to severe complications with a death rate as high as 13% if left untreated. . Many cases with a history of non-mouse bites and symptoms characterized by fever, rash and joint pain are often difficult to diagnose and mistaken for other diseases. Emphasizing the standards of epidemiology and clinical manifestations helps support the diagnosis and treatment of diseases.

Clinical and epidemiological

Just because the mouse bite, this patient had to be hospitalized for 4 days before the fever ended.(Photo: Tu Anh (Dan Tri).

Rat bite is an animal-borne disease transmitted by humans through bites or scratches of animals belonging to rodents, especially rats, or some pets (such as dogs, cats .). According to the pathogenic and clinical causes we distinguish:

1. Sodoku disease, described by Japanese authors, is caused by Spirillum minus.
2. Haverhill fever, described by American author, caused by Streptobacillus moniliformis.

Sodoku disease (mouse rash disease caused by Spirillum)

Sodoku is the Japanese compound of two words So is mouse, doku is poisoned. From the blood of patients suffering from human disease, the bacteria were isolated, named Spirillum minus in 1924. Bacteria are short-lived Gram-negative bacteria with 2 or 3 turns and cannot grow in human culture. create.

Epidemiology

Spirillum minus often causes mouse bite fever in Asia and some scattered cases are reported in Africa, Australia, Europe and America. Spirillum minus is found in the tongue muscles of healthy mice, house mice, cats and dogs. The disease is transmitted by people randomly, directly through a bite or scratch, or indirectly through contact or ingestion of urine-contaminated foods by a bacterial infection. 25% of rats tested had S. minus.

Clinical manifestations

The incubation period of Sodoku is usually from 5 to 4 weeks, sudden onset with high fever (39-40 degrees C), chills and characterized by fever intermittent fever. Individual fevers recurrence are separated by fever-free periods commonly found in spirillum.

The recurrence of a fever may occur several times over 1 to 3 months. At the same time manifesting skin syndrome such as pruritic rash, dystrophy, tend to be interconnected, concentrated in the scalp, face and upper body. In the bitten area, skin lesions may go away on their own, but in most cases it can become an area of ​​swelling, redness and necrosis.

During the period of the disease, patients may show joint pain, which may develop into arthritis. In some patients may manifest neurological symptoms: headache, hallucinations, delirium leading to coma. Possible complications such as endocarditis, meningitis, infarction, hepatitis, pleurisy, epididymitis, anemia. If left untreated, the fever will last 1-2 months, causing a 6-10% death rate.

Diagnosis and manifestations of mouse bite disease

Rat bite is a disease transmitted by humans to humans.

Rat fever caused by Spirillum is often diagnosed by the isolation of bacteria in the blood, lymph nodes, bites and skin lesions. Spirillum minus can be detected through a black background microscope or in contrast phase, or Giemsa staining, Wright dyeing or silver staining. Minus Spirillum bacteria are short, twisted, Gram negative (0.2-0.5µm wide and 3-5µm long), have flagella on both ends. There is currently no success in cultivating bacteria in artificial environments. If bacteria, blood or ooze cannot be detected in the wound, inject into mice to diagnose by isolating S. minus.

Haverhill fever (mouse bite caused by Streptobacillus moniliformis)

Rat fever is caused by treptobacillus moniliformis S known as Haverhill fever, Haverhill fever is described in India 2000 years ago and it is more popular than Sodoku disease. In 1926, Streptobacillus moniliformis was identified as the cause of disease in the town of Haverhill in Massachusetts.

Epidemiology

Streptobacillus moniliformis is a Gram-negative, aerophilic, non-mobile bacilli, without shell, a polymorphic bacilli. They are usually spherical, oval, rhombic, stick-shaped, in some cases, bacteria rolled into cubes. They are found in the nose of the mouse. The disease appears scattered in some poor families.

Haverhill fever is popular everywhere in the world, often in the US and European countries. Human transmission occurs directly through a mouse bite or scratch or occurs indirectly through ingesting unprocessed food contaminated with or contaminated with urine from infected mice, or possibly Indirect transmission through contact between unprotected hands and mice and sick animals in the laboratory. Streptobacillus moniliformis enters the body through healthy skin.

Clinical manifestations

Incubation period of 3-10 days. Sudden symptoms of infection with high fever syndrome (39-40 degrees C), chills, headache. When Streptobacillus moniliformis enters the gastrointestinal tract, the patient will experience gastrointestinal symptoms such as vomiting or nausea. Muscle and joint pain may appear with pain characteristics moving from one joint to another.

During the course of the disease, the infection syndrome appears persistent. Symptoms of skin may indicate purpura that appears on the palms, legs, and nose. Half of the patients exhibited rheumatism or an infection of the joints asymmetrically, concentrated in large joints. It is described that the diseased joints due to discrete, unrelated Streptobacillus moniliformis. The fever will recede after 3-5 days even if no antibiotic treatment and inflammatory joints disappear within 10 to 14 days.

Possible complications: endocarditis, myocardial infarction, pericarditis, pneumonia, meningitis, anemia.

Diagnose

In humans, rat fever caused by Streptobacillus moniliformis is diagnosed by transplanting blood, joint fluid, and fluid from the wound. Depending on the culture medium, bacteria can grow alone or in chains.

Streptobacillus moniliformis is difficult to grow and must be cultured in 20% plasma, blood or ascites. The laboratory must be suspected by a diagnostic notice, the bacteria do not grow well in normal environments. The method of infection for rodents is also used for diagnosis. The diagnosis with human serum does not mean much. PCR reactions are not used to diagnose in humans because the price is too expensive.

Treatment and prevention of mouse fever

Treatment

The incidence of more than 25% of untreated patients. The treatment of rodent fever is associated with the care of the mouse bite. The wound care includes wound cleaning and tetanus vaccination. Rats and rodents are not infected with rabies virus and there has been no report of transmission of rabies virus to humans from this group of animals.

The wound care includes wound cleaning and tetanus vaccination.

In the study of invitro, Streptobacillus moniliformis is sensitive to penicillin, ampicillin, azithromycin and doxycycline, and resistant to polymyxin B, gentamycin, ciprofloxacin, levofloxacin. Erythromycin is sensitive in the study but when applied in clinical practice, it failed.

Recommendations

Adults

1. Intravenous penicillin (2 million units every 4 hours) for 5-7 days, continue treatment if clinically improved with ampicillin (500mg / 4 times / day) orally for 7 days.
2. If the patient is allergic to penicillin, tetracylin can be used (500mg 4 times / day) or doxycylin 100mgx2 times / day.

Children

1. Intravenous penicillin (20,000-50,000 units / kg / day divided 6 times / day), maximum dose of 1.2 million units / day. For patients with no indication for admission to penicillin V treatment (25mg / kg / day orally 3-4 times / day). Treatment lasts 7-10 days.
2. For patients with penicillin allergy, severe clinical disease, can be treated with doxycylin. Although tetracyclines have side effects that cause discoloration in children, this side effect is very small for short-term doses. For children weighing more than 45kg, doses can be used as adults. Younger children take a dose of 2-4mg / kg divided 2 times / day.
3. Streptomycin can be used to treat both adults and children, although there are some barriers to using this drug such as drug toxicity, family requirements or some pharmacies without this drug.

Prevention

The clinical course of fast and dangerous mouse bite. Disease prevention depends on recognizing the risks and possible symptoms of the disease of people who are exposed to mice.

The dose of penicillin for 3 days (2g / day for adults; 25,000 to 50,000 units / kg / day for children) is recommended when bitten by mice, although the effectiveness of antibiotic prophylaxis has not been checked. proof.

Preventing diseases includes killing rats in the city, destroying unpasteurized milk and potentially contaminated water, using gloves when handling animals and cleaning their pens.

Summary and recommendations

1. Rat bite disease is a difficult to diagnose disease, caused by whole-body disease caused by Spirillum minus and Streptobacillus moniliformis. Streptobacillus moniliformis causes most cases in the United States, Spirillum minus often causes illness in Asia, although they are present worldwide.
2. People often get sick through bites or scratches of infected or infected mice, contact with infected or gastrointestinal mice through food or water contaminated with rat waste.
3. Symptoms of rabies fever appear suddenly with symptoms of high fever, muscle pain, joint pain, nausea, headache and then a rash on the face and nose. Polyarthritis can occur in about half of patients. Possible complications include meningitis, myocarditis, pneumonia and multiple organ failure.
4. Diagnosis through isolation of bacteria (with Spirillum minus) or culture (with Streptobacillus moniliformis) blood or joint fluid, inflammatory fluid. Cultivation is often difficult, usually over 21 days. There are no diagnostic serological tests to date.
5. Intravenous penicillin is the first choice. Empirical treatment in patients with a history of exposure and clinical symptoms before the assertion of the test is due to a long time of determination.
6. The dose of penicillin taken for 3 days (2g / day for adults and 25,000 - 50,000 units for children) is recommended for people with exposure, although the evidence is unclear.

Suffering from sodoku because of a mouse bite