Hantavirus Cardiopulmonary Syndrome Due to Imported Andes Hantavirus Infection in Switzerland: A Multidisciplinary Challenge, Two Cases and a Literature Review

Abstract

Two travellers returning from South America were diagnosed with Andes hantavirus infection, the only member of the Hantaviridae family known to be transmitted from person to person. We describe the clinical course and therapeutic and infection control measures. While both patients showed high viral load (VL) and shedding over several months, 1 patient recovered within 1 week from severe respiratory illness that required noninvasive ventilation, whereas the second patient developed severe hantavirus cardiopulmonary syndrome that required extracorporeal membrane oxygenation for 27 days. The clinical course in the latter patient was complicated by severe disseminated intravascular coagulopathy with diffuse hemorrhage that necessitated mass transfusions, as well as by multiple organ failure, including the need for renal replacement therapy. Results of VL in blood, respiratory secretions, and semen for the first 9 months of follow-up are reported. To our knowledge, these are the first cases of Andes hantavirus infection detected in Europe.

Figure 1.

Evolution of hemoglobin and thrombocyte values and corresponding transfusion needs for patient 2. Abbreviation: Hb, hemoglobin.

Figure 2.

Chest radiography, day 3, and chest computed tomography scan with contrast enhancement, day 11, of patient 2.

Figure 3.

Course of Andes hantavirus RNA and anti-Andes hantavirus immunoglobulin (Ig) G/IgM antibodies for patient 1 (A) and patient 2 (B). RNA levels were assessed using in-house quantitative real-time polymerase chain reaction (qRT-PCR); measurements where a pronounced qRT-PCR inhibition was observed are marked with as asterisk (*). Serological parameters were assessed qualitatively by IgM/IgG immunoblot assay (IBA) (Euroline Hantavirus profile global, Euroimmun) and semiquantitatively by enzyme-linked immunosorbent assay (ELISA; Hantavirus Profile global, Euroimmun) by determining test-sample-to-calibrator ratio with a ratio of ≥1.1 rated positive (borderline ratio ≥0.8 to <1.1); for IgG, a ratio of 8 corresponds to 260 RU/mL, a ratio of 5 to 160 RU/mL, and a ratio of 0.8 to 16 RU/mL. Comment on patient 1: viral load on day 1 was from a serum sample, and from day 4 onward from EDTA blood. On day 3, high Andes hantavirus (ANDV) viral load (8.07 × 10⁵ GE/mL) in whole blood contrasted with a substantially lower load in serum (2.82 × 10⁴ GE/ml) from the same day. Comment on patient 2: She tested negative for ANDV by RT-PCR in serum and for specific antibodies 1 week before onset of symptoms. Two days after admission, a high virus load was found in whole blood (1.07 × 10⁶ GE/mL) and Hantavirus-specific IgM (ratio 2.5) and IgG antibodies (ratio 8.73) were detected by ELISA and IBA.