MERS-CoV transmitted from animal-to-human vs MERS-CoV transmitted from human-to-human: Comparison of virulence and therapeutic outcomes in a Saudi hospital

Purpose: To examine virulence (seventy of disease and/or symptoms) and response to therapy (medications, supportive measures) between confirmed cases of MERS-CoV animal-to-human transmission compared with cases resulting from human-to-human transmission. Methods: The records for laboratory-confirmed MERS-CoV infections that were diagnosed at King Fahad Hofuf Hospital (Al-Ahsa, Saudi Arabia) from April 1, 2012 to November 30, 2016 were reviewed retrospectively. Results: There were 107 laboratory-confirmed MERS-CoV cases. Transmission of the virus from animal-to-human was less common (21.4 vs 78.6 %). The human-to-human transmission group had a higher mortality rate (53.57 vs 39.13 %). Patients in this group also had higher APACHEE II (11.2 vs 23, p = 0.043), SOFA scores (10.9 vs 12.55, p = 0.076), and higher rates of sepsis (17.39 vs 26.19%, p = 0.582) and septic shock (13.04 vs 20.23 %, p = 0.555). The infections were more severe in the human-to-human transmission group; patients had increased rates of intensive care unit (ICU) admission (43.47 vs 51.19 %), decreased time from symptom onset until ICU admission, and greater need for mechanical ventilation (8 days vs 4 days, p = 0.041, and 6 days vs 4 days, respectively), longer time to respond to antiviral treatment and resolve the infection (5 days vs 11 days and 7 days vs 13 days, respectively) and a shorter time from the beginning of symptoms until death (11 days vs 5 days, p = 0.048). Conclusion: MERS-CoV transmitted from human-to-human was more virulent, resulted in higher case-mortality rates and required more ICU treatment.