Abu Dhabi, United Arab Emirates (CNN) -- Saudi health officials are stepping up efforts to fight the Middle East respiratory symptom coronavirus, or MERS-CoV, after a recent spike in cases.
Saudi Arabia confirmed more than 50 cases of the virus in the past week, at least seven of which were fatal. The Saudi Health Ministry says 13 new cases were reported Monday alone, bringing the total to 257.
It is not clear why there was a sudden increase, said Dr. Abdullah Al-Asiri, assistant undersecretary at the Saudi Ministry of Health and a member of the Scientific Committee of Infectious Diseases.
"We have faced an increase in the number of cases around the same time last year at the end of winter," the Saudi Press Agency quotes him as saying.
Last week, reports on social media said health care workers had refused to treat MERS-CoV patients. The government has since issued a statement saying ambulance services that refused would be suspended from work and investigated.
Saudi officials have also called on the World Health Organization and a group of medical experts to meet at the end of this month to discuss the status of the virus.
In a prepared statement, Ministry of Health spokesman Khalid Marghalani said a drug company would be arriving in Saudi Arabia to discuss the production of a vaccine to fight the virus.
MERS-CoV was discovered in September 2012. The World Health Organization reported Sunday that 250 cases have been confirmed globally with 93 deaths worldwide.
A new cluster of the virus was reported in the United Arab Emirates this week, as were the first cases in Greece and Malaysia.
MERS-CoV comes from the same group of viruses as the common cold and attacks the respiratory system, the U.S.-based Centers for Disease Control and Prevention says. Symptoms, which include fever, cough and shortness of breath, can lead to pneumonia and kidney failure.
Although many of the cases have occurred on the Arabian Peninsula, people have died of the infection elsewhere, including in European countries and Tunisia in North Africa. However, all of the people involved contracted the disease in the Middle East before being diagnosed. Limited human-to-human transmission of the disease has also occurred in other countries.
Health officials do not know exactly how the virus spreads, and they stress hygiene, such as diligent hand-washing, to limit its spread.
The WHO has not recommended any MERS-related travel restrictions but says member countries should monitor any unusual respiratory infection patterns in travelers to the Arabian Peninsula.
After the spike in cases, Dr. Abdullah bin Abdulaziz Al-Rabiah stepped down as minister of health, state media reported Monday.