Plague disease , history of plague ,symptoms , prevention ,treatment and vaccination of plague.

 PLAGUE

Rats and their fleas are primarily affected by the bubonic plague (Xenopsylla cheopis). When a human gets bitten by an infected flea, they become infected. The bacteria grow inside the flea's stomach by building a mucilaginous clog at the gizzard's entrance, which prevents the flea from getting food and makes it starve. The flea, which never stops being hungry, then bites repeatedly to feed.

History

The bacterium that causes plague was discovered in 1894 by two bacteriologists working in Hong Kong, Shibasaburo Kitasato of Japan and Alexandre Yersin of France. Although both researchers published their findings, Kitasato's ambiguous and inconsistent remarks eventually led to the primary discovery of the organism being credited to Yersin. In honour of the Pasteur Institute in Paris, where Yersin worked, he gave it the name Pasteurella pestis. To honour Alexandre Yersin, it was called Yersinia pestis in 1967.

Paul-Louis Simond, a French scientist working in China to combat the pandemic, discovered that the rat-flea was the disease's vector in 1898.

Pathology

Man is bitten by an infected flea, which then contaminates the wound with blood vomit that has plague bacteria in it. When phagocytosed, Yersinia pestis can still survive inside a macrophage because they can proliferate inside of cells. Bacteria enter lymphatic system after entering body. One of the poisons released by plague germs is known to result in serious beta-adrenergic blockage. The disease-associated "bubo" is caused by the way Y. pestis moves through the lymphatic system of the infected person until it reaches a lymph node, where it triggers severe hemorrhagic inflammation that causes the lymph nodes to enlarge.

The bloodstream is where lymphatics ultimately empty into, which allows the plague bacteria to enter and spread to any organ of the body. In septicemic plague, blood capillaries in the skin and other organs burst, leaving skin covered in dark patches. On the skin, there are red, bite-like pimples. Septicemic plague is always lethal if left untreated, although early antibiotic therapy lowers the fatality rate to between 4 and 15%. Often, those who contract this type of plague pass away on the same day that their first symptoms manifest.

The pneumonic plague attacks the lungs, where it then spreads from person to person by respiratory droplets spat forth. Pneumonic plague typically has an incubation period of two to four days, however it can occasionally just last a few hours. The earliest signs and symptoms of headache, weakness, and hemoptysis-producing cough are similar to those of other respiratory disorders. The infection can be lethal without identification or treatment in one to six days, with a death rate of 50 to 90%.

Symptoms

An incubation period of 3 to 7 days is frequently followed by the onset of flu-like symptoms in infected individuals. The quick onset of symptoms such as fever, chills, weakness, nausea, vomiting, and head and body aches is usual for patients. Depending on the route of infection, the clinical plague infection might present in one of three ways: bubonic, septicaemic, or pneumonic.

 The most prevalent type of plague brought on by a flea bite is bubonic plague. From the bite site, the plague bacillus enters the skin and moves through the lymphatic system to the closest lymph node. The plague germs then multiply in great numbers in the lymph node, causing inflammation. The swollen lymph node is known as a "bubo," which is extremely painful and can develop into an open sore when the infection is advanced. In most cases, the bubonic plague symptoms start to show two to eight days following the flea bite. The bubo is often enlarged and 1 to 10 cm in diameter in the armpit, neck, or groyne. Warm and unpleasant to the touch It may be so painful that you are unable to move the body part that is being impacted. Although more than one bubo can form, most frequently only one area of your body is affected by a bubo.

When an infection spreads via the bloodstream without a visible "bubo," it is called septicaemic plague. Flea bites and direct contact with infectious materials through skin crevices can result in septicaemic plague.

The most severe and uncommon type of plague, pneumonic plague, develops as a result of a subsequent spread from an initial bubonic form's advanced infection. Primary pneumonic plague can spread from person to person without the help of fleas by way of inhalation of infectious droplets sprayed into the air by coughing patients. The fatality rate for untreated pneumonic plague is extremely high.

PREVENTION

People who live and work in places where the plague is a serious threat should adopt the following safety measures:

• Eliminate rodent-friendly food sources and hiding spots near residences, workplaces, and popular recreation areas like campgrounds and picnic areas. Get rid of the clutter, pet food, rock piles, and brush.

• During plague epidemics in wild animals, health officials should use appropriate and approved pesticides to exterminate fleas.

• Pets like cats and dogs should receive routine flea treatment.

• Animals that are sick or dead should be avoided, and the health department should be informed. When skinning an animal, hunters and trappers should put on rubber gloves.

• When outdoors in places where exposure to fleas is a possibility, use insect repellents.Antibiotic preventive therapy is advised for:

• Individuals who are bitten by fleas or who come into contact with bodily fluids or tissues from a plague-infected animal.

• Residents of a home where a patient has the bubonic plague, as they can come into contact with infected fleas.

• Individuals in close proximity to a person or animal who may have plague pneumonia. Travelers should take the following extra measures when visiting areas where the plague is a problem
• Avoid coming into contact with sick rats' fleas. After a significant number of plague-infected rats have perished, the danger of getting bitten by infected fleas is very high. Therefore, stay away from areas where rats are a problem.
• Apply bug repellents to your legs and ankles if you absolutely must visit to such places. Apply repellents and insecticides on exterior bedding and clothing as well.
• If there is a high possibility of exposure, use preventative antibiotics.

TREATMENT

The first plague antibiotic was created and tested by Vladimir Havkin, a medical professional of Russian and Jewish descent who practised in India. The conventional therapies are:

30 mg/kg of body weight of streptomycin taken twice daily for seven days

Chloramphenicol is administered as a single dose of 25–30 mg/kg followed by four doses of 12.5–15 mg/kg daily.

Tetracycline is taken as a 2 g single dose, followed by 500 mg four times each day for seven to ten days. Children should not use the medication.

Gentamicin 2.5 mg/kg twice day for seven days.

It has also been demonstrated that doxycycline 100 mg (for adults) or 2.2 mg/kg of body weight (for children), taken orally twice day, is efficacious.

VACCINATION

Although once widely utilized, plague vaccines have not shown to be helpful at preventing the disease. In cases of an outbreak, vaccinations are not advised for protection. Only high-risk groups, such as laboratory workers who are continually exposed to the possibility of contamination, are advised to get vaccinated as a preventive step.

For adults in the high-risk group, a formalin-inactivated vaccine is available, but severe inflammatory reactions frequently occur. After the initial intramuscular injection, boosters are administered at 3, 5, and 6 months, respectively. Then, three additional booster doses are administered at 6-month intervals, followed by doses spaced 1-2 years apart.

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