Hantavirus Pulmonary Syndrome in Pregnancy

Lung tissues from 73 rodents (Apodemus agrarius coreae) gave specific immunofluorescent reactions when they reacted with sera from patients convalescing from Korean hemorrhagic fever. Similar staaining was observed in the lungs of A. agrarius inoculated with acute-phase sera obtained from two patients with this disease. The unidentified agent was successfully propagated in adult A. agrarius through eight passages representing a cumulative dilution of greater than 10(-17). Experimentally inoculated rodents developed specific fluorescent antigen in the lung, kidney, liver, parotid glands, and bladder. Organs, especially lungs, were positive beginning 10 days and continuing through 69 days after inoculation. The agent could not be cultivated in several types of cell cultures nor in laboratory animals. No fluorescence was observed when infected A. agrarius lung tissues were reacted with antisera to Marburg virus, Ebola virus, and serval arenaviruses. Diagnostic increases in immunofluorescent antibodies occurred in 113 of 116 severe and 11 of 34 milder cases of clinically suspected Korean hemorrhagic fever. Antibodies were present during the first week of symptoms, reached a peak at the end of the second week, and persisted for up to 14 years. Convalescent-phase sera from four persons suffering a similar disease in the Soviet Union were also positive for antibodies.

In May 1993 an outbreak of severe respiratory illness occurred in the southwestern United States. A previously unknown hantavirus was identified as the cause. In Asia hantaviruses are associated with hemorrhagic fever and renal disease. They have not been known as a cause of human disease in North America. We analyzed clinical, laboratory, and autopsy data on the first 17 persons with confirmed infection from this newly recognized strain of hantavirus. The mean age of the patients was 32.2 years (range, 13 to 64); 61 percent were women, 72 percent were Native American, 22 percent white, and 6 percent Hispanic. The most common prodromal symptoms were fever and myalgia (100 percent), cough or dyspnea (76 percent), gastrointestinal symptoms (76 percent), and headache (71 percent). The most common physical findings were tachypnea (100 percent), tachycardia (94 percent), and hypotension (50 percent). The laboratory findings included leukocytosis (median peak cell count, 26,000 per cubic millimeter), often with myeloid precursors, an increased hematocrit, thrombocytopenia (median lowest platelet count, 64,000 per cubic millimeter), prolonged prothrombin and partial-thromboplastin times, an elevated serum lactate dehydrogenase concentration, decreased serum protein concentrations, and proteinuria. Rapidly progressive acute pulmonary edema developed in 15 of the 17 patients (88 percent), and 13 patients, all of whom had profound hypotension, died (case fatality rate, 76 percent). Increases in the hematocrit and partial-thromboplastin time were predictive of death. Infection with a newly described hantavirus causes the hantavirus pulmonary syndrome, which is characterized by a brief prodromal illness followed by rapidly progressive, noncardiogenic pulmonary edema.