What is Argentine hemorrhagic fever?
Argentine hemorrhagic fever is an acute viral disease related to zoonoses with natural foci. It is characterized by fever, exanthema, and different severity of thrombohemorrhagic syndrome.
Causes of Argentine hemorrhagic fever
The causative agent of Argentine hemorrhagic fever – Junin virus (after the name of the city where the first cases of the disease are registered) refers to arenaviruses, which include the pathogens of Lassa fever and Bolivian hemorrhagic fever. The virus is pathogenic for newborn white mice and hamsters. Cultured in chicken embryos and in a culture of transplantable cells.
The reservoir and source of infection are rodents Calomis laucha, Calomis musculinus. Viruses were also isolated from gamasid mites. The incidence is characterized by seasonality – from February to June, the peak of incidence in May. Mostly villagers get sick. Infection occurs by airborne dust, inhaling dust infected by rodents. Infection can occur through food infected with the urine of rodents. Epidemic outbreaks were observed annually, the number of cases ranged from 100 to 3500 people.
Pathogenesis during Argentine hemorrhagic fever
Many issues of pathogenesis are not well understood. Gates of infection are the mucous membranes of the respiratory organs and the digestive tract, possibly through microtrauma of the skin. At the site of the gate infection of primary affect is not observed. Characterized by the dissemination of the virus and the defeat of a number of organs and systems. The development of the thrombohemorrhagic syndrome plays a major role in the pathogenesis.
Symptoms of Argentine hemorrhagic fever
The incubation period lasts from 7 to 16 days. The disease begins gradually. Body temperature rises, sometimes with chills, weakness, headache, muscle pain, nausea, vomiting, anorexia. Fever increases and reaches 39-40 ° C. On examination, revealed hyperemia of the face, neck, vascular injection of the sclera. There may be a slight swelling of the lymph nodes. On the 3-5th day of illness, the patient’s condition worsens, there are signs of dehydration (BP drops to 50-100 mmHg), and oliguria increases. In more severe forms, pronounced manifestations of thrombohemorrhagic syndrome develop: hematemesis, melena, gingival bleeding, nosebleeds, hematuria. Changes in the nervous system are possible – excitement, delirious state, stupor. On the 7-10th day, shock and gastrointestinal bleeding may occur. In fatal cases, the cause of death is usually pulmonary edema.
Diagnosis of Argentine hemorrhagic fever
Take into account the epidemiological data (stay in an endemic area, incidence, etc.) and characteristic clinical symptoms. Work on the specific interpretation of the diagnosis can only be carried out in laboratories, specially equipped to work with especially dangerous viruses. It should be borne in mind that antibodies appear no earlier than 10-20 days from the onset of the disease. Need to differentiate from other hemorrhagic fevers.
Treatment of Argentine hemorrhagic fever
It has been shown that the introduction of immune plasma significantly reduces mortality (from 16% to 1%) in an experiment on monkeys, the effectiveness of ribavirin (virazole) was shown. Pathogenetic therapy is carried out (rehydration, hemodialysis, etc.).
Prognosis: Mortality usually ranges from 3 to 15%.
Prevention of Argentine hemorrhagic fever
Specific prevention is not developed. The destruction of rodents living in houses.