After a fourth person was diagnosed with the plague yesterday, the government has ramped up efforts to contain the deadly disease. Authorities are checking all people leaving the province for signs of a fever, one of the key symptoms of the plague. A program to exterminate rats and fleas, which carry the disease, was also launched in Inner Mongolia after the fourth victim was diagnosed there yesterday.
The victim was an unidentified farmer from Ulanqab in south Inner Mongolia and was said to be in a stable condition.
Those who had come into contact with the herder were quarantined, officials said.
Authorities have launched a public awareness campaign in a further effort to stop the spread of disease.
Three other cases have been confirmed in the Xilingol League province.
One man was treated for the bubonic plague after he ate a wild rabbit, while the first two patients were diagnosed with the more fatal and contagious pneumonic strain.
The couple who were first diagnosed with the pneumonic strain on November 12, were later transferred to Beijing.
They said their home was infested with rats.
According to the World Health Organisation (WHO) the pneumonic plague can be fatal if left untreated and is extremely contagious.
From 2010 to 2015, 3248 cases were reported worldwide, including 584 deaths.
Pneumonic plague is also referred to as lung-based plague, as it is a severe lung infection.
WHO warn the disease can be transmitted via droplets to other humans and if not diagnosed and treated early, it can be fatal.
But the international health organisation say that recovery rates are high if detected and treated in time, usually within 24 hours of the onset of symptoms.
Typical symptoms include the sudden onset of fever, chills, head and body aches, vomiting and nausea.
The second strain of the plague is called the bubonic plague, which is the most common form.
The bubonic plague is caused by the bite of an infected flea, causing the lymph node to become inflamed, tense and painful.
At advanced stages of the infection the inflamed lymph nodes can turn into open sores filled with pus.
Bubonic plague can then spread to the lungs and advance to pneumonic plague.
The plague is caused by the bacteria Yersinia pestis, which is usually found in small mammals and their fleas.
Humans can become infected by the bite of infected flea, unprotected contact with infectious bodily fluids or contaminated materials, or through contact with another infected patient.