Plague – Yersinia Pestis Disease

Yersinia Pestis Disease or Plague is a highly contagious bacterial disease caused by enterobacteria yersinia pestis. Plague was once a worldwide pandemic disease that killed millions of people. However, nowadays, it is still active in sub tropical and tropical warm areas.

Enterobacteria yersinia pestis circulates in fleas that feed on the blood of rodents in a cycle involving both of them. In tropical and subtropical areas Yersinia pestis circulates in a cycle involving rodents and their fleas to maintain their existence. [1]

Why it was called Yersinia pestis?

Alexandre Yersin, a scientist of france named it Pasteurella pestis in honor of the Pasteur Institute France where he worked, but it was renamed to yersinia pestis in his honor in 1967.[9]

No need for Plague immunization unless you live in high risk zones.[4]

Mode of transmission of Plague

1. By direct contact (direct touch/droplet inhalation) – sexual contact, or even by touching a contaminated soil
2. Fecal oral transmission through contaminated food and water
3. Airborne transmission through air droplets, by respiration of contaminated air droplets via coughing or sneezing
4. Through infected animals

Forms of plague

• Bubonic plague in lymph nodes
• Septicemic plague in blood vessels
• Pneumonic plague in lungs
• Pharyngeal plague
• Meningeal plague

Nowadays Plague is treatable with early detection; yet, plague is still endemic in some parts of the world. according to WHO and CDC outbreaks of ‘bubonic plague’ occurred annually in the coastal city of Mahajanga, Madagascar.[3][6]

In the U.S. 15 cases of bubonic plague were reported back in 2015.[2][7]

Bubonic plague is the most common form of plague, the infection develops fast once Yersinia is in the body, the bacteria penetrates the lymphatic system, which is a tissue drainage system. In norm the lymphatic system drains the interstitial fluids (tissue and cellular fluids) and returns excess amounts of fluid to the bloodstream thus balancing the blood pressure and defending the body against infections. However, Y. pestis a gram-negative bacteria secretes several endotoxins, one of which is known to cause a dangerous beta-adrenergic blockade, which results in chronic heart failure.[1][9]

Yersinia pestis spreads through the lymphatic tunnels and all the way until it reaches a lymph node, where it stimulates severe hemorrhagic inflammatory reactions, forcing the lymph nodes to swell and expand ‘swollen lymph nodes’.

The expansion of lymph nodes is the reason for the formation of “bubons from bubo” associated with this disease.

Septicemic plague is a life threatening bacterial infection of the blood, which arises from the lymphatic tunnels, from where infection penetrates the bloodstream causing sepsis, a generalized blood infection accompanied by intravascular coagulation “DIC”, which will lead into ischemic necrosis of all tiny tissues where toxin clots are stuck. Septicemic plague is deadly, all patients die within few hours from the onset of symptoms.

Symptoms of Septicemic plague

Most symptoms of Septicemic plague are caused by micro clots, of those symptoms:

• Bleeding into the skin and other organs causing reddish -black patchy rash
• Patients are known to cough blood (hemoptysis), or vomit blood (hematemesis).[1]
• Bumps or skin lesions, which appear like insect bites, having a reddish color, and white core.

Pneumonic plague usually develops within few hours, and up-till 4 days following a droplet contamination, the onset of symptoms shows after the incubation period, and as a rule the diseases starts as a regular flu with fever, headache, weakness. However, the disease progress rapidly and the patient’s condition regress, the clinical picture presents with hemoptysis (a tuberculosis like coughing with blood), or hematemesis (vomiting blood), the disease is highly contagious and fatal, especially if untreated properly, if untreated Pneumonic plague has a 100% fatality rate in humans, deaths due to ‘Pneumonic plague’ occur within a couple of days following the onset of symptoms.[11]

This form of plague is considered deadly because its indistinguishable from several other illnesses such as Acute Respiratory Diseases,  Acute respiratory distress syndrome (ARDS) and Chronic Obstructive Pulmonary Disease (COPD), which may trick doctors and lead to death.

Laboratory diagnosis of plague and the identification of prominent virulence markers of Y. pestis strains.

How to identify yersinia pestis?

Diagnosis is made by taking samples from the patient. Samples may be obtained through lymph node aspirates from buboes, blood, throat swabs or sputum, and submitting them for laboratory testing, which involves detection of Y. pestis using procedures such as real-time PCR or Multiplex-PCR.

How do you cure plague and what antibiotics are used to treat plague?

The drug of choice is streptomycin up to 3.0g daily. however, for localized forms of plague, dosage adjusted appropriately up to 4.0g daily.

Combination antibiotic therapy is used for the treatment of generalized forms. Combinations of streptomycin and tetracycline are often used to treat generalized forms of plague.

The course of treatment of patients with plague ranges from 7-10 days for all forms.

Plague history timeline

Plague hunted the lives of nearly 200 million people in Europe and the Mediterranean basin alone, especially in the 14^th century where it spread from central Asia to south Russia and from there to Constantinople, France before it spread all over west Europe.[10]

14th Century P. Epidemy

It is known that the world lost half of its population in the medieval era because of Plague, and it took Europe a couple hundred years to recover from this disaster, though the old continent has never fully revived.

Other names to plague: Black Death, Zombie disease, life hunter, Yersinia pestis disease, the ottoman fever.

References

1. emc.healthyorthodoxmedicine.com
2. cdc.gov/mmwr/preview/mmwrhtml/mm6433a6.htm
3. cnn.com/2015/10/22/health/plague-cases-2015-cdc/
4. cdc.gov/outbreaks/
5. medscape.com/viewarticle/432069
6. who.int/mediacentre/factsheets/fs267/en/
7. livescience.com/51974-plague-united-states-2015.html
8. ibtimes.com/bubonic-plague-us-disease-still-present-colorado-madagascar-1729792
9. en.wikipedia.org/wiki/Plague_(disease)
10. historytoday.com/ole-j-benedictow/black-death-greatest-catastrophe-ever
11. en.wikipedia.org/wiki/List_of_human_disease_case_fatality_rates

Verified by: Dr.Diab (October 8, 2017)

Citation: Dr.Diab. (October 8, 2017). Yersinia Pestis Disease – Plague. Medcoi Journal of Medicine, 17(2). urn:medcoi:article15714.