Although the number of total cases has continued to increase, this is because of “enhanced surveillance and ongoing investigations,” the WHO said; some of the cases were not actually infected, upon inspection.
The epidemic remains active in 12 districts, and among the total cases reported, 61% are said to be the pneumonic plague, according to the UN office.
This is faster-spreading and more transmittable than bubonic plague, noted Tarik Jasarevic, a spokesman for the WHO; “compared with past outbreaks, this year there is a higher portion of pneumonic plague cases.”
Since plague is endemic (or regularly found) in Madagascar, its “spread to non-endemic areas which were not used to handling plague cases, including densely populated cities,” may have caused a more severe outbreak, according to Jasarevic.
The unusual spread of pneumonic plague in this outbreak was due to one infected person who traveled to find care early in the outbreak, infecting people along the way. These individuals infected others, leading to several chains of transmission, added Nyka Alexander, a representative of the WHO Health Emergencies Programme.
Ongoing efforts to control the spread of bubonic and pneumonic plague include seeking out and treating new cases, identifying the method of disease contact, disease follow-up and antibiotic treatment, rodent and flea control, and “safe and dignified burials,” the WHO said in a statement.
Low risk of international spread
Extensive screening measures, informed travelers, short incubation periods of pneumonic plague, and increasing operational readiness of surrounding countries and islands has kept the risk of international spread low, said the WHO.
“The risk of international spread is low, because generally, people with plague are too sick to travel,” said Dr. Charlotte Ndiaye, a WHO representative in Madagascar.
Her organization is working closely with airport authorities to ensure that sanitary measures such as temperature checks and medical teams are in place at airports and ports to prevent the spread of infection outside the country. The group is also working closely with neighboring countries.
Travel and trade restrictions have not been advised, but travelers arriving in Madagascar should be informed about the outbreak and the necessary protection measures. These include avoiding crowded areas; avoiding contact with dead animals, infected tissues and materials; avoiding close contact with other patients; using repellent to prevent bug bites; and knowing where to seek medical treatment, according to the WHO.
It’s “important to recognize that, unlike Ebola, plague is easily treated with antibiotics,” said Daniel Bausch, director of the UK Public Health Rapid Support Team, “with very good outcomes, as long as detected and treated early.”
Treatment and prevention
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.
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 — coughing or sneezing. The incubation period is short, and an infected person may die within 12 to 24 hours.
Symptoms of the plague include fever, chills, painful and inflamed lymph nodes, or shortness of breath with coughing and/or blood-tainted sputum arise. It is important to seek medical attention immediately if any of these arise, Jasarevic said.
Both forms of the plague can be treated with antibiotics, making early detection a priority.