By the bioMérieux Connection Editors
While plague in Madagascar is not unusual, the 2017 Madagascar plague outbreak was one of the most severe in recent history. As serious as this public health threat is, the World Health Organization (WHO) and the Centers of Disease Control and Prevention (CDC) are trying to calm the hysteria being fueled by exaggerated claims in popular media, such as:
According to the WHO’s “Plague – Madagascar” website for Emergency Preparedness, from August 1 to November 10 of 2017, Madagascar witnessed 2,119 confirmed, probable and suspected cases of plague.
- These cases have resulted in 171 deaths, which is an 8 percent fatality rate
- Of the 2,119 confirmed and suspected cases, 1,618 (76%) have been classified as pneumonic plague. Of the 171 fatalities, 72 deaths have been clinically classified as pneumonic plague
- The WHO reports that of the 2,119 confirmed and suspected cases, 324 cases (15%) were bubonic plague
- Only a single case was confirmed to be septicemic plague
- 176 cases (8%) are unspecified cases of the plague
According to the Centers of Disease Control and Prevention, the plague occurs semi-annually in Madagascar, but this outbreak was unusual because of the high rate of plague pneumonia cases that have occurred.
- Plague is a bacterial infection caused by the Gram-negative bacteria Yersinia pestis
- It is typically spread through bites by infected fleas
- Bubonic plague occurs when the Y. pestis infection is acquired by flea bite. Bubonic plague causes symptoms of high fever and swollen and tender lymph nodes that usually occur 2–6 days after the flea bite
- Septicemic plague occurs when Y. pestis enters the blood stream
- Plague pneumonia occurs if Bubonic plague is not treated and the infection spreads to the lungs
- According to the CDC, plague pneumonia (or “pneumonic plague”) is the only form that can be directly transmitted from one person to another
- In rare but serious cases, a person with severe plague pneumonia can spread the infection directly to others by coughing up droplets that contain the plague bacteria
- These bacteria-containing droplets can cause pneumonic plague in another person if breathed in
- Symptoms of plague pneumonia typically appear 2–4 days after inhaling plague bacteria
- If antibiotics are prescribed quickly, plague can be treated effectively
- Neither WHO nor CDC have confirmed that the 2017 Madagascar plague is antibiotic resistant or multi-drug resistant, as has been widely reported
- The WHO has cultured 25 isolates of Y. pestis from the current outbreak and all are sensitive to antibiotics
Plague Outlook for 2018
According to WHO, since the beginning of the outbreak, a total of 7,122 contacts were identified. Of these, 6,729 (95%) completed their 7-day follow up and a course of prophylactic antibiotics. Only nine of the nearly 7,000 contacts developed symptoms and became suspected cases of plague.
The WHO reports that the number of new cases and hospitalizations of patients due to plague is declining in Madagascar. The last confirmed bubonic case was reported on October 24, 2017, and the last confirmed pneumonic case was reported on October 28, 2017.
Since plague is endemic to parts of Madagascar, WHO expects more cases to be reported until the end of the typical plague season in April 2018
According to WHO, 82 healthcare workers in Madagascar “have had illness compatible with plague, none of whom have died.”
Opinions expressed in this article are not necessarily those of bioMérieux, Inc.