9. Diagnosis and treatment of hantavirus infections
Epidemiological information and clinical symptoms are useful for the initial diagnosis of hantavirus infections. Confirmation of hantavirus infections should be based on clinical symptoms, epidemiological information, and detection of the nucleic acids, proteins, and/or antibodies specific to the associated hantavirus.65
No specific antivirals have been approved for HFRS and HCPS/HPS in the USA or Europe.5 However, some antivirals, including ribavirin, fapilavir, and lactoferrin, have displayed varying efficacy in the treatment of hantavirus infections.91
Prophylactic administration of ribavirin and fapilavir in early infection or post-exposure has shown some efficacy.92 Both ribavirin and fapilavir have shown anti-hantavirus activity in vivo and in vitro.5,91 Ribavirin has proven effective in the early treatment of HFRS with some limitations, including toxicity to humans and animals at high doses and the potential to cause hemolytic anemia.92 Fapilavir is superior to ribavirin without the side effect associated with anemia.77 Fapilavir was evaluated in an ANDV/SNV-infected hamster model, where oral administration twice daily at 100 mg/kg significantly reduced the viral RNA load in the blood and the antigen load in the lung. Oral administration of fapilavir before the onset of viremia prevented HCPS, whereas delayed administration had no protective effect.91
Antibodies include monoclonal and polyclonal antibodies.91 Monoclonal antibodies that are effective against hantaviruses have been demonstrated in hamster models and suckling mouse models.91 Monoclonal antibodies have been proven effective for treatment of HCPS/HPS induced by ANDV infection in hamster models.93 Polyclonal antibodies produced by DNA-vaccinated bovines have also displayed protective effects in animal models.65
Supportive treatment can be used to maintain fluid and electrolyte balance in HFRS patients, while blood transfusions can control bleeding and improve clotting in DIC cases. For HCPS/HPS patients, oxygen supplementation is usually required.5