An international team of researchers studied 23 cases at four hospitals in Saudi Arabia, which included 15 fatalities, a mortality rate of 65 percent, the New England Journal of Medicine reported.
So far Saudi Arabian authorities have confirmed 49 cases of MERS, including 32 deaths from the mysterious virus.
Since the first recorded case in Saudi Arabia in April last year, the World Health Organization has reported 64 cases of MERS (Middle East Respiratory Syndrome), with 39 fatalities, a mortality rate of 59 percent.
MERS is part of the same family of coronaviruses as SARS (Severe Acute Respiratory Syndrome), which has killed nearly 800 people worldwide since 2003.
The higher mortality rate of victims in medical establishments is a cause for concern, the researchers wrote.
"The rapid transmission and high attack rate in the dialysis unit raises substantial concerns about the risk of health care-associated transmission of this virus," the study said.
Of the 23 cases studied, 21 resulted from direct person-to-person transmission.
"Person-to-person transmission of MERS-CoV can occur in health care settings and may be associated with considerable morbidity. Surveillance and infection control measures are critical to a global health response," the study said.
The researchers traced the route of infection at the four hospitals where the cases had been found, finding links between family members visiting patients as well as hospital staff.
MERS sufferers exhibit similar symptoms to people infected with SARS, starting with a low-grade fever and a mild cough which may persist for several days before the development of pneumonia. Some individuals also develop gastrointestinal problems, another SARS hallmark.
The average incubation period for MERS is four days, with 95 percent of infected people developing symptoms within 10 days, researchers said.
In addition to Saudi Arabia, isolated cases of MERS have been found in Great Britain, Italy, Tunisia and France.