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Transcript of Typhoid Fever - Web view Typhoid fever is also called enteric fever in some cultures. Typhoid fever

Yrsinia pestis: The Bacteria That Causes the Bubonic Plague

The bacteria that causes the bubonic plague is usually spread through the bite of an infected rodent or flea. This bacteria is called Yersinia pestis and infects 1,000 to 3,000 people each year. Within two to six days of exposure to the bacteria that causes the bubonic plague, symptoms may develop, including headache, chills, fever, and swollen lymph glands.


Yersinia pestis bacteria causes about 1,000 to 3,000 plague cases each year, mostly in Africa, Asia, and South America. Between 10 to 20 cases occur annually in southwest areas of the United States.

Yersinia pestis is found most commonly in rats, but is occasionally found in other animals. Some of these animals include:

· Fleas, * Mice * Prairie dogs * Wood rats

· Chipmunks * Lice * Cats *Dogs * Squirrels.

How Is the Bacteria That Causes the Bubonic Plague Transmitted?

Usually, the bacteria that causes the bubonic plague is contracted when someone is bitten by an infected flea or rodent. In rare cases, it is possible for a piece of contaminated clothing or other material used by an infected person to transmit bacteria through a cut or other opening in your skin and infect you. Bubonic plague is rarely spread from person to person.

Yersinia pestis bacteria begin to multiply once they reach the lymph nodes. (The lymph or lymphatic system is a major component of your body's immune system. The organs within the lymphatic system are the tonsils, adenoids, spleen, and thymus.)

Within two to six days of exposure to the bacteria that causes the bubonic plague, symptoms may develop including :

Swollen, tender lymph glands (called buboes, hence the name bubonic. Turn black = “black death” ).

The Black Death was one of the most devastating pandemics in human history, peaking in Europe between 1348 and 1350, and killing between 75 million and 200 million people.[1][2][3] Although there were several competing theories as to the etiology of the Black Death, recent analysis of DNA from victims in northern and southern Europe indicates that the pathogen responsible was the Yersinia pestis bacterium probably causing several forms of plague.[4][5]

The Black Death is thought to have started in China or central Asia.[6] It then travelled along the Silk Road and reached the Crimea by 1346. From there, it was probably carried by Oriental rat fleas living on the black rats that were regular passengers on merchant ships. Spreading throughout the Mediterranean and Europe, the Black Death is estimated to have killed 30 to 60 percent of Europe's population.[7] All in all, the plague reduced the world population from an estimated 450 million to a number between 350 and 375 million in the 14th century.

The aftermath of the plague created a series of religious, social and economic upheavals, which had profound effects on the course of European history. It took 150 years for Europe's population to recover. The plague reoccurred occasionally in Europe until the 19th century.

Mycobacterium tuberculosis the bacteria which causes tuberculosis

Tuberculosis, ( TB ) is a lethal, infectious disease caused by Mycobacterium tuberculosis.[1] The bacteria which causes tuberculosis was first isolated in 1882 by a German physician named Robert Koch who received the Nobel Prize for this discovery.

Tuberculosis typically attacks the lungs, but can also affect other parts of the body. It is spread through the air when people who have an active TB infection cough, sneeze, or otherwise transmit respiratory fluids through the air.

The classic symptoms of active TB infection are a chronic cough with blood-tinged sputum, fever, night sweats, and weight loss. Many years ago, this disease was referred to as "consumption" because without effective treatment, these patients often lose weight and would “waste away” as if being consumed.. Today, of course, tuberculosis usually can be treated successfully with antibiotics. , if left untreated, kills more than 50% of those so infected. TB is thought to be the all time leading killer of human beings by a single pathogen.

One third of the world's population is thought to have been infected with M. tuberculosis,[3] with new infections occurring at a rate of about one per second.[3] In 2007, there were an estimated 13.7 million chronic active cases globally,[4] while in 2010, there were an estimated 8.8 million new cases and 1.5 million associated deaths, mostly occurring.

Treatment is difficult and requires administration of multiple antibiotics over a long period of time. Social contacts are also screened. In times past.. people with TB were quarantined . This means they were not allowed to be in contact with anyone else. Today Antibiotic resistance is a growing problem

How does a person get TB?

A person can become infected with tuberculosis bacteria when he or she inhales minute particles of infected lung droplets called sputum from the air. The bacteria get into the air when someone who has a tuberculosis lung infection coughs, sneezes, shouts, or spits (which is common in some cultures). People who are nearby can then possibly breathe the bacteria into their lungs. You don't get TB by just touching the clothes or shaking the hands of someone who is infected. Tuberculosis is spread (transmitted) primarily from person to person by breathing infected air during close contact.

Mycobacterium leprae the bacteria which causes Leprosy

· Leprosy is a slowly developing, progressive disease that damages the skin and nervous system.

· Leprosy is caused by an infection with Mycobacterium leprae or M. lepromatosis bacteria.

· Early symptoms begin in cooler areas of the body and include loss of sensation.

· Signs of leprosy are painless ulcers, skin lesions, and eye damage (dryness, reduced blinking). Later, large ulcerations, loss of fingers and toes, skin nodules, and facial disfigurement may develop.

· The infection is thought to be spread person to person by nasal secretions or droplets. Leprosy can be transmitted to humans from chimpanzees, and nine-banded armadillos…. by droplets or direct contact.

· Susceptibility to getting leprosy may be due to certain human genes.

· Antibiotics are used in the treatment of leprosy.

What is leprosy?

Leprosy is a disease caused by the bacteria Mycobacterium leprae, which causes damage to the skin and the nervous system. The disease develops slowly (from six months to 40 years!) and results in skin lesions and deformities, most often affecting the cooler places on the body (for example, eyes, nose, earlobes, hands, feet, ) The skin lesions and deformities can be very disfiguring and are the reason that infected individuals historically were considered outcasts in many cultures.

Most human leprosy is transmitted from another human. , However, three other species can transfer M. leprae to humans: 1. chimpanzees, 2. mangabey monkeys, and 3. nine-banded armadillos.

Streptococcus pyogenes “FLESH EATING BACTERIA” causes Necrotizing Fasciitis

What is necrotizing fasciitis?

Necrotizing fasciitis is a term that describes a disease condition of rapidly spreading infection, under the skin. The infection is usually located in connective tissue around muscles, nerves and blood vessels. These types of connective tissue are called “FASCIA” That is why the disease is called necrotizing FASCIITIS”. The infection results in dead and damaged tissue. . The disease can occur in almost any part of the body.

Over 70% of cases are recorded in patients with one of the following clinical situations: a depressed immune system…, diabetes,… alcoholism/drug abuse…../smoking, malignant tumors., … but also, rarely occurs in healthy people[7]

The infection begins locally at a site of trauma, which may be severe (such as the result of surgery), minor, or even non-apparent. Patients usually complain of intense pain that may seem excessive given the external appearance of the skin. With progression of the disease, often within hours, tissue becomes swollen. Diarrhea and vomiting are also common symptoms.

In the early stages, signs of inflammation may not be apparent if the bacteria are deep within the tissue. If they are not deep, signs of inflammation, such as redness and swollen or hot skin, develop very quickly. Skin color may progress to violet, and blisters may form, with subsequent necrosis (death) of the subcutaneous tissues.

Furthermore, patients with necrotizing fasciitis typically have a fever and appear very ill. Mortality rates have been noted as high as 73 percent if left untreated.[8] Without surgery and medical assistance, such as antibiotics, the infection will rapidly progress and will eventually lead to death.[9]

Micrograph of necrotizing fasciitis, showing necrosis (center of image) of the dense connective tissue, i.e. fascia, interposed between fat lobules (top-right and bottom-left of image). H&E stain.

"Flesh-eating bacteria" is not an accurate term. The bacteria do not actually "eat" the tissue. They cause the destruction of skin and muscle by releasing toxins

SALMONELLA typhi: The bacteria which causes typhoid fever.

1. Typhoid Fever

· Typhoid fever is also called enteric fever in some cultures. Typhoid fever is caused by the species salmonella typhi. The infection is spread from ingesting contaminated water or food that contains fecal matter of an infected person. S. typhi resists destruction from the host's immune system, but it is usually cleared without medication. If the condition pers