The village of Mandritsara, where 20 people recently died from bubonic plague. (Flickr / Peter Stephens)

To most, the plague is a thing of the past — a relic from the Middle Ages, when the disease known as the Black Death wiped out a third of Europe's population. Yet despite being wiped out across much of the globe, it's still very much a reality in parts of Madagascar, where one of the worst outbreaks in recent memory has left dozens dead.

Last week, government officials announced that 39 people have died this fall from pneumonic plague — a rare and extremely deadly strain of the illness that affects the respiratory system. According to Madagascar’s health ministry, pneumonic plague can kill a patient within three days of infection, leaving little time for antibiotics to take effect.

The announcement came just days after experts at the Pasteur Institute of Madagascar confirmed that bubonic plague killed 20 people in the northwest town of Mandritsara, and two months after the International Committee of the Red Cross (ICRC) warned that Madagascar was at risk of a plague epidemic.

"There is an epidemic in Madagascar."

"There is an epidemic in Madagascar which is currently affecting five districts" out of 112, the ministry said in a statement on Thursday. "Eighty-six people have been inflicted by the plague, of which 39 have died."

Patients infected with bubonic plague typically suffer from flu-like symptoms, gangrene, and swollen lymph nodes. The disease spreads through the bites of infected rodent fleas, which primarily use black rats as their hosts. Bubonic plague can be treated with antibiotics, reducing mortality rates from 60 percent to 15 percent, but the pneumonic form — which typically starts as bubonic plague before spreading to the lungs — is far more dangerous. If left untreated, mortality rates approach 100 percent, and can remain high if a patient doesn’t receive antibiotics within 24 hours of infection. It also spreads through air droplets, meaning that unlike the bubonic plague, it can be transmitted from human to human.

Plague is rare across most of the globe today, due in large part to better sanitation and the development of new drugs. But it remains persistent in parts of Asia and Africa — which account for an estimated 90 percent of the world's cases — and especially in Madagascar, a low-income island nation of more than 22 million people. Since 2009, an average of 500 cases have been reported every year in Madagascar, according to data from the ICRC. Last year, the country saw 256 plague cases that resulted in 60 deaths, more than anywhere else in the world.

Infection rates typically rise during Madagascar's hot and rainy season, which lasts from October to April, when fleas begin breeding and transmission increases. The disease predominantly affects the rural highlands of Madagascar's central and northern regions, where poverty rates are high and sanitation is poor, though it's been known to spread within crowded prisons, as well.

"we can't destroy all the rodents on the planet."

Dr. Christophe Rogier, director of the Pasteur Institute of Madagascar, says there's no shortage of antibiotics in the country, but getting them to the remote highlands — many of which are inaccessible by car — remains an enormous challenge.

"These epidemics generally occur in very remote and rural areas," Rogier says. "The housing is not very safe, and there are a lot of rats and rodents." In a recent case, it took Rogier and his team more than two days to reach remote villages, delaying urgently needed treatment for patients with pneumonic plague.

There are social and cultural factors to consider, as well. In the most recent outbreak, many villagers thought it was the work of a spirit or curse rather than plague, and therefore didn’t seek medical treatment until it was too late. Poverty and illiteracy rates remain high in these areas, and when patients do seek help, it's often in the form of witch doctors or other traditional healers.

Rogier says it's difficult to say how this year's outbreak compares with those of the past, though he acknowledges that ongoing political turmoil has worsened conditions on the ground. Tensions have been high in the country since 2009, when current president Andry Rajoelina seized power in a military-backed coup. The crisis led to a suspension of international aid, which has put extra strain on Madagascar's public health facilities while exacerbating poverty levels. The country will hold presidential run-off and legislative elections on Friday, though there are concerns that the process may be rigged, further muddying an already unclear future.

"what happened in the Middle Ages could happen again."

The Pasteur Institute of Madagascar, together with the WHO and the public health ministry, have been working for years to combat plague by administering bedside diagnostic tests, distributing antibiotics, and using pesticides to control flea populations. Rogier says this month's outbreak is now considered to be under control, noting that no new cases have been reported in four of the five districts, though he and other experts acknowledge that complete eradication remains impossible. "The human disease can't be eradicated, since we can't destroy all the rodents on the planet," Dr. Eric Bertherat, a plague expert at the WHO, said in an email.

Awareness campaigns and ongoing monitoring are therefore crucial going forward, experts say, but efforts have been hampered by a relative dearth of international funding. Plague isn't nearly as common as malaria, dengue fever, or other tropical diseases, and as a result, research and control campaigns aren't as well-funded. Yet Rogier argues that despite its scarcity, future plague outbreaks could have potentially devastating impacts, especially considering the fragile state of Madagascar's economy and public health system.

"If we imagine that there is a preliminary case in the capital or in big cities, there will be hundreds and thousands of cases, and surely hundreds and thousands of deaths," he says. "In actuality, what happened in the Middle Ages could happen again."