An unusually widespread outbreak of the plague is menacing Madagascar.
At least 24 people have died and more than 130 have been infected with plague across the country, according to the World Health Organization.
Plague is endemic to the country, but "contrary to past outbreaks, this one is affecting larger urban areas and ports, which increases the risk of person-to-person transmission," WHO spokesman Tarik Jasarevic said.
Among the reported cases, almost 60 were the more common bubonic plague, including seven deaths. More than 70 -- including 17 deaths -- are suspected to be pneumonic plague, which is more severe.
Ten cities were reporting pneumonic cases as of September 30, including the capital, Antananarivo, increasing chances of the disease spreading.
Plague is caused by infection with the bacterium Yersinia pestis and is typically spread through the bite of infected fleas, frequently carried by rats, causing bubonic plague. Symptoms include painful, swollen lymph nodes, called bubos, as well as fever, chills and coughing.
Pneumonic plague is more virulent or damaging and is an advanced form characterized by a severe lung infection. The infection can be transmitted from person to person via airborne droplets. The incubation period is short, and an infected person may die within 12 to 24 hours.
An unusual outbreak
An estimated 400 cases of plague are reported in Madagascar every year, mostly the bubonic variety, but the current outbreak has affected more areas and started earlier than usual.
It's also unusual for large urban areas to be affected, as they have been this year, the WHO states.
Outbreaks typically occur during the rainy season as "the rains drive the rodents out," said Daniel Bausch, director of the UK Public Health Rapid Support Team. Launched in 2016, this team consists of clinicians, scientists and academics deployed to tackle outbreaks of disease around the world within 48 hours.
Bausch is sending two of his team members to Madagascar this week to collaborate with the WHO, which is assembling a team of experts to help the Madagascar Ministry of Public Health.
"The thing that is unusual is that this is the beginning of the season," Bausch said. "Usually, after six months, you have around 200 cases. Now, we have (more than) 130 in just the first month of the season."
It's also unusual that more than half of the cases reported are of pneumonic plague, he said.
The outbreak began after the death of a man in the central highlands of the country -- a plague-endemic area -- after which the Ministry of Public Health began investigating and tracing his contacts, according to the WHO.
In late September, a man from the Seychelles, in Madagascar to take part in the Indian Ocean Club Championship basketball tournament, died in a hospital from pneumonic plague. Health officials are urgently tracing individuals who had contact with the man and have started an investigation into the case.
Treatment and prevention
The government has mobilized resources to spray schools and other public places to fight fleas and rodents and curb the spread of infection.
People have also been lining up at pharmacies in the capital -- some wearing face masks -- to get medications or protection from infection.
If treated quickly, plague can be cured with common antibiotics, but authorities have warned people not to self-medicate. Rapid diagnosis is the essential element in curing plague, particularly the pneumonic strain.
Some public events have been banned, and children have been asked to stay home.
"People associate plague as one of those fearful diseases, but it's a concern if not treated," Bausch said. It's now important to ensure means "to control the rodents and identify and treat people early."