BEIJING-- China increased its alert against the Middle East Respiratory Syndrome (MERS) over the past week, as the country's first patient in, a South Korean national, recovers in the hospital.

China is on high alert for MERS following an outbreak that swept the Republic of Korea (ROK) over the past few weeks.

With the approach of the annual pilgrimage of Chinese citizens to Saudi Arabia, where the MERS virus was first discovered, the risk of imported cases cannot be ruled out due to the frequent people exchanges, a circular issued by China's top health authorities said on Friday.

Medical institutions should strengthen monitoring of fever and pneumonia cases with unidentified causes in order to detect, diagnose and isolate MERS patients as soon as possible, said the document.

Provincial capitals and port cities should select hospitals for MERS cases and emergency medical centers should have ambulances meeting requirements for respiratory infectious disease prevention, it added.

The country has updated and improved its 2014 edition of a guideline for diagnosis and treatment of MERS cases.

China's quarantine and inspection, health and tourism authorities renewed a joint circular to prevent MERS cases from entering the country last Tuesday.

The circular requires those from countries or regions with MERS outbreaks to report actively to quarantine and inspection authorities if they are experiencing fever, coughing or having breathing difficulties.

Customs and quarantine inspection departments in China have strengthened coordination and prevention efforts.

At a temperature monitoring area in the Entry-Exit Inspection and Quarantine Bureau of Zhuhai City in Guangdong Province, an information board with instructions in Chinese and English was erected to tell those with the above symptoms to report their conditions to authorities.

The bureau has drilled its personnel on MERS knowledge and prevention.

China's civil aviation regulator has also ordered all airline companies to strengthen prevention and control of MERS for flights between China and the ROK on Friday.

Airline companies operating flights between the two countries should increase flight crew's awareness of the disease, intensify disinfection of airplanes and act quickly in treatment of suspected MERS cases, said a statement of the Civil Aviation Administration of China.

Some domestic airlines in China have decided to suspend some flights to the ROK.

Sichuan Airlines said it will suspend its direct flights to Jeju, one of the ROK's leading destinations for Chinese tourists, for one month, after the final flight on Friday.

Despite no official travel warning from the government, Chinese travelers are feeling jittery over visits to the ROK due to the MERS epidemic.

Chinese travel agencies predict a 70-percent drop or more in summer travel to the ROK as fearful tourists urgently book alternative destinations.

Judging from the current situation, the possibility of isolated MERS cases in China cannot be ruled out, but an epidemic is not likely, said Jin Qi, director of the Institute of Pathogen Biology of the Chinese Academy of Medical Sciences.

"Having gone through SARS, China now has a high awareness of potential epidemics and its monitoring and testing technologies are significantly improved," he said, adding China can handle an outbreak of communicable diseases.

A deadly Severe Acute Respiratory Syndrome (SARS) epidemic spread across China in 2003. It was a watershed event in the country's public health history that prompted huge preparation efforts for disease outbreaks and changes in transparency of information.

ROK MERS PATIENT IN CHINA RECOVERING

The first MERS patient in China, a 44-year-old ROK national, has tested negative twice after finishing treatment a week ago, said Deng Xilong, a doctor with Guangzhou No. 8 People's Hospital.

"Generally, two negative results means the patient can be discharged from hospital. We still have insufficient understanding of the virus. To ensure no risk at all, we need to continue our observation," said Deng, who joined the treatment of the ROK patient in the Central Hospital of Huizhou City, Guangdong.

The patient tested positive for MERS while in Guangdong Province on May 29. He was displaying symptoms as early as May 21 in his country. Despite doctors' advice for him to cancel his travel plans, he flew to Hong Kong on May 26, entering Huizhou City via Shenzhen.

All 75 people in Guangdong who had been in close contact with him were released from quarantine on Thursday.

MERS infections in the ROK increased to 145 Sunday since the first case was reported on May 20, with 14 fatalities.

The World Health Organization on Saturday strongly advised South Korea to ban all people suspected of being infected with MERS or having contact with the MERS infectees from going abroad.

The number of total death cases from MERS has risen to 453 in Saudi Arabia, which has reported 1030 MERS infections since the outbreak of the deadly disease in 2012.

There is still no cure or vaccine for MERS, while current treatment has largely been supportive care.