As millions of Muslims make the religious pilgrimage, known as Hajj, to Mecca in Saudi Arabia this October, health officials have warned visitors to the holy site to wear masks in order to prevent the spread of Middle East respiratory syndrome (MERS). In Saudi Arabia, 44 people have died from the highly transmissible coronavirus.

According to the World Health Organization (WHO), 80 people have been infected worldwide. Though the number of MERS cases is much smaller than the roughly 8,000 people infected with SARS and 775 deaths worldwide in 2003-2004, health officials are concerned that the SARS "cousin" virus may spread quickly through close contact between travelers or throughout hospital settings.

Hajj, Arabic for pilgrimage, occurs annually as one of the five pillars of Islam, and must be carried out at least once in a lifetime by every Muslim if he or she is capable. Health officials said it was important to maintain personal hygiene during the pilgrimage, using tissues when sneezing or coughing and taking precautionary vaccinations.

WHO released an update stating that one of the most recent cases of the virus was a 56-year-old woman from the northeastern region of Saudi Arabia, who is a health care worker "with contact of a previously reported laboratory confirmed MERS-CoV case." Half of the total cases have been female health workers.

Cases have been identified in Jordan, Qatar, Saudi Arabia, the United Arab Emirates (UAE), France, Germany, Italy, Tunisia, and the UK.

The coronavirus was first detected in the Arabian peninsula in September 2012. It is part of a large family of viruses, ranging from the common cold to SARS (severe acute respiratory syndrome).

"The clinical syndrome is similar to SARS, with an initial phase of nonspecific fever and mild, nonproductive cough, which may last for several days before progressing to pneumonia," a study published in the New England Journal of Medicine stated.

The same study showed that there was a risk for the virus to be transmitted through hospitals, though it's still unknown how exactly the coronavirus is spread.

The WHO noted that MERS could most likely be passed between people in close contact, though it's still unknown if MERS can infect through super-spreaders, people with the virus who don't show any symptoms of the disease but are able to transmit it to others.

"Health care facilities are reminded of the importance of systematic implementation of infection prevention," WHO stated. "[They] should take appropriate measures to decrease the risk of transmission of the virus to other patients, health care workers and visitors."