Lassa fever

Lassa fever: symptoms, diagnosis and treatment

Lassa fever is an acute viral disease that belongs to the group of zoonoses and is characterized by severe disease and high mortality. This disease has a natural focal nature and can affect many human organs and systems, including the respiratory system, kidneys, central nervous system and myocardium.

Etiology and pathogenesis

Lassa fever is caused by an arenavirus, which can be transmitted to humans through contact with the polymammated rat, which is a reservoir of infection in nature. Infection can occur through alimentary and airborne droplets, through microtraumas of the skin, as well as through airborne dust.

Characterized by hematogenous dissemination of the virus and damage to many organs and systems. The fragility of blood vessels increases, profound disorders of hemostasis occur and DIC syndrome develops. Hemorrhages are most pronounced in the intestines, liver, myocardium, lungs, and brain.

Symptoms and course

The incubation period for Lassa fever lasts from 3 to 21 days, most often 5-8 days. The disease begins relatively gradually and the severity of fever and symptoms of intoxication increases every day.

In the initial period, patients note general weakness, weakness, general malaise, moderate muscle pain and headache. Body temperature increases and after 3-5 days reaches 39-40 °C. Fever may last up to 3 weeks. Symptoms of intoxication also increase, such as asthenia, muscle pain and disturbances of consciousness.

In the initial period, in the majority of patients (80%), a characteristic lesion of the pharynx appears - on the arches of the tonsils and the soft palate there are foci of necrotic changes of a yellowish-grayish color, surrounded by a zone of bright hyperemia. Their number then increases, they can merge, and the plaques can resemble fibrinous plaques.

On the 5th day of illness, pain in the epigastric region, nausea, vomiting, and copious loose, watery stools may appear. Sometimes dehydration develops. In severe forms of the disease, in the 2nd week the symptoms of intoxication sharply increase, pneumonia, pulmonary edema, myocarditis, swelling of the face and neck, and hemorrhagic syndrome occur.

During this period, death is possible in 15-20% of patients.

Diagnostics

Diagnosis of Lassa fever includes clinical and laboratory approaches. It is clinically important to identify characteristic symptoms and a history of contact with the pathogen.

Laboratory diagnostics include:

1. Isolation of the virus from the patient’s blood, urine, saliva, semen and other biological materials;
2. Serological methods - determination of antibodies to the virus in patient blood;
3. PCR diagnostics - detection of viral RNA in patient biological materials.

Treatment

Treatment of Lassa fever is carried out in an infectious diseases department and includes symptomatic therapy and specific antiviral treatment. Symptomatic therapy includes: hydration, correction of hemostasis disorders, treatment of pneumonia, myocarditis and other complications.

For specific antiviral treatment, the drugs ribavirin and interferon are used. The effectiveness of their use depends on the stage of the disease and the time of treatment. It is important to ensure effective infection control measures to prevent the spread of disease in the population.

**Lassa fever** is a serious disease that is transmitted through mosquito or rodent bites, as well as from an infected person to a healthy person. This is a viral disease that causes severe **fever** and sometimes hemorrhages (excessive bleeding). Fever can be fatal in 5% of cases.

The source of the disease is a human carrier of the lassa virus. It is usually not contagious to healthy people, but in rare cases it can become a source of infection. The disease is transmitted through mosquitoes and rodents. There may also be cases of transmission of infection by airborne droplets, for example, when coughing

Lassa fever is an infectious disease caused by a virus called Lassa virus. It is transmitted through the blood and can cause serious complications, including bleeding, kidney failure and death. In some cases, lassi fever is defined as a syndrome, since it is not an independent disease, but only a symptom that can be caused by other, more serious diseases.

Lassa virus was first discovered in West Africa in 1962. It got its name in honor of the city of Las Vegas, which became the site of the first case of human infection. It was subsequently discovered that the virus is transmitted through mosquito bites, as well as through contact with infected animals or body fluids.

Symptoms of lassi fever can vary from person to person, but typically include fever, headache, fatigue, rash, cough, irritability and decreased appetite. In more severe