Friday, November 21, 2014

WHO: Plague Returns To Madagascar

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Location of Island of Madagascar

 

# 9359

 

Bubonic Plague (Yersinia Pestis) is a bacterial infection transmitted by fleas, carried by infected rats.   The infection generally sets up in the lymphatic system, resulting in the tell-tale buboes, or swollen lymph glands in the the groin, armpits, and neck. 

Plague signs

Credit CDC

 

The most common presentation is Bubonic plague, however in rare cases, Pneumonic Plague may develop.  Here the infected person develops a severe pneumonia, with coughing and hemoptysis (expectoration of blood), and may spread the disease from human-to-human.

 

Since plague is fairly easily treated with antibiotics, it isn’t much of a public health menace in the developed world. In areas where treatment isn’t readily available, however, mortality rates run 40%-60% and untreated pneumonic plague is almost always fatal.


Last year, we saw an outbreak in Madagascar that claimed 39 lives (see Bubonic Plague: Forgotten, But Not Gone), and earlier this summer we briefly saw the Chinese city of Yumen sealed off after a plague death was reported there (see Xinhua News: Plague Quarantine Lifted In NW China).  

The United States typically sees 5 or 6 sporadic cases each year as well.

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South central Africa, and the island of Madagascar, are home to more than half the human cases of plague reported each year to the World Health Organization.   Since the early 1990s, Madagascar has reported multiple outbreaks, often with hundreds of cases. After respite over the summer, it appears that plague has returned once more to Madagascar, as reported by the World Health Organization in an update today.

 

Plague – Madagascar

Disease outbreak news
21 November 2014

21 November 2014 - On 4 November 2014, WHO was notified by the Ministry of Health of Madagascar of an outbreak of plague. The first case, a male from Soamahatamana village in the district of Tsiroanomandidy, was identified on 31 August. The patient died on 3 September.

As of 16 November, a total of 119 cases of plague have been confirmed, including 40 deaths. Only 2% of reported cases are of the pneumonic form.

Cases have been reported in 16 districts of seven regions. Antananarivo, the capital and largest city in Madagascar, has also been affected with 2 recorded cases of plague, including 1 death. There is now a risk of a rapid spread of the disease due to the city’s high population density and the weakness of the healthcare system. The situation is further complicated by the high level of resistance to deltamethrin (an insecticide used to control fleas) that has been observed in the country.

Public health response

The national task force has been activated to manage the outbreak. With support from partners – including WHO, the Pasteur Institute of Madagascar, the “Commune urbaine d’Antananarivo” and the Red Cross – the government of Madagascar has put in place effective strategies to control the outbreak. Thanks to financial assistance from the African Development Bank, a 200,000 US dollars response project has been developed. WHO is providing technical expertise and human resources support. Measures for the control and prevention of plague are being thoroughly implemented in the affected districts. Personal protective equipment, insecticides, spray materials and antibiotics have been made available in those areas.

Background

Plague is a bacterial disease caused by Yersinia pestis, which primarily affects wild rodents. It is spread from one rodent to another by fleas. Humans bitten by an infected flea usually develop a bubonic form of plague, which produces the characteristic plague bubo (a swelling of the lymph node). If the bacteria reach the lungs, the patient develops pneumonia (pneumonic plague), which is then transmissible from person to person through infected droplets spread by coughing. If diagnosed early, bubonic plague can be successfully treated with antibiotics. Pneumonic plague, on the other hand, is one of the most deadly infectious diseases; patients can die 24 hours after infection. The mortality rate depends on how soon treatment is started, but is always very high.

WHO recommendations

WHO does not recommend any travel or trade restriction based on the current information available. In urban areas, such as Antananarivo, the surveillance of epidemic risk indicators is highly recommended for the implementation of preventive vector control activities.

 

According to the CDC: Between 1,000 and 2,000 cases each year are reported to the World Health Organization(WHO), though the true number is likely much higher. The last really big plague outbreak was in India  20 years ago, as summarized by the WHO.

During August 26-October 5, 1994, a total of 5150 suspected pneumonic or bubonic plague cases and 53 deaths were reported from eight states of India, primarily in the south-central and southwestern regions.

 

Although there is no vaccine available, with the advent of effective antibiotics, large scale outbreaks of plague are increasingly rare.  Still, the risk of infection is not zero, and so the CDC has some advice on how to avoid this illness by way of this 2-page PDF file.

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