First MERS Autopsy Reveals the Virus' Organ Target
The findings differed from those in animal models, bringing to light new information on the virus.
Of the 1,500 patients who have been diagnosed with the Middle East Respiratory Syndrome (MERS), around one-third of them of died from the illness. The first autopsy report from one of those people has finally become available.
MERS-CoV first appeared in humans in 2012 after a patient was diagnosed in Saudi Arabia. Since then, the viral respiratory illness has made its way to several countries, including the United States. Unfortunately, a significant amount of patients succumb to the condition.
The first autopsy comes from a 45-year-old male who quickly went from symptoms of a fever, runny nose, and cough to death between April 2 and April 10, 2014. He worked in the storage room at a paramedic station and did not care for patients or have exposure to camels (a suspected transmission route). The patient was treated at a hospital in the United Arab Emirates and was given 100 mg of the steroid hydrocortisone every eight hours on his last day. The autopsy was performed 10 days after his death and it has been described in The American Journal of Pathology.
MERS-CoV is new to humans and as such, researchers do not exactly know how the virus infects patients. Individuals at an increased risk of sickness include those who travel to the Arabian Peninsula, are exposed to camels, and are in close contact with someone with confirmed MERS-CoV.
Often times, patients with MERS-CoV show signs of acute kidney failure. The autopsy results, however, did not show evidence of the virus in the patient’s kidneys.
“This suggests that the acute renal failure in this patient was not caused by direct renal infection, but likely by other factors such as hypotension,” lead investigator Sherif R. Zaki, MD, PhD, chief of the Infectious Diseases Pathology Branch at the Centers for Disease Control and Prevention in Atlanta, said in a news release.
It appears that MERS-CoV’s main organ target were the lungs. The researchers found anti-MERS-CoV antibodies in the pneumocytes and epithelial syncytial cells in the lungs, as well as in the bronchial submucosal glands.
“Infection of bronchial submucosal glands is a likely source of viral shedding in respiratory secretions leading to human-to-human transmission,” Zaki explained. The findings differed from those found in animal models, which shows the importance of human pathology.
David H. Walker, MD, director of the University of Texas Medical Branch (Galveston) Center for Biodefense and Emerging Infectious Diseases, says that the long interval between first diagnosis and first autopsy was a missed opportunity. It has been noted, however, that autopsies in the United States have dropped significantly over the past few years. Insight on MERS-CoV was gained through multiple animal models, but obviously, animal models do not have all of the same features as humans.
“Until the truth-testing of a large series of autopsies is reported, judgment will favor those models supported by the observations in a single postmortem examination,” said Walker, who was not affiliated with the study.
The takeaway on this new research is that although this autopsy provides great insight into MERS-CoV, more than one autopsy is needed to fully understand its pathology.