Typhus

Definition

Typhus is a group of diseases caused by rickettsial infection. There are mainly two types of typhus; endemic and epidemic depending upon the type of Rickettsia involved. The bacteria usually spread from an infected person through bite of fleas, lice, mite even ticks. Common symptoms include high fever with chill and rigors with characteristic rashes all over the body.

Anyone can suffer from typhus but people living or traveling to endemic countries, having poor hygiene, living in an overcrowded area are at more risk of suffering from typhus. Without appropriate treatment about 10 to 60% of epidemic typhus patients may die whereas death occurs in only 2% cases of endemic typhus without treatment. Antibiotics are the mainstay of treatment.

Symptoms

Symptoms usually depend upon the type of typhus. Epidemic typhus presents with :

  • High persistent fever with chill and rigor. Fever may be as high as 104◦F.
  • Dry cough with severe headache, generalized body pain and fatigue.
  • Intolerance to bright light (photophobia), rashes which are macular or maculopapular starting on the trunk and then gradually spreading to other body parts, sometimes the rashes may appear as hemorrhagic spots.
  • Joint pain and pain in the lower back.
  • Confusion, hallucination, delusion and disorientation.
  • Painful swelling of glands.

Endemic typhus also present with a similar type of symptoms.

  • Scrub typhus is another type of typhus characteristically presents with aswelling at the site of bite by the mite. With time this small lesion may become enlarged with necrosis of the central portion of the lesion. It is replaced by a black colored-thick (scab). Swelling of lymph nodes may occur all over the body or typically at the site of mite bite.

Epidemic typhus is the most serious type of typhus leading to number of complications like gangrene and subsequent loss of limbs and fingers, neurological problems like disorientation, confusion even coma and impairment of function of multiple organs may ultimately lead to death.

Causes

Typhus is an acute disease caused by infection with Rickettsia, a type of bacteria which lives inside the mites. The infecting arthropod vector carrying the bacteria feeds on human blood and passes stool containing the bacteria. This triggers an itchy sensation in the skin of the person. Scratching leads to abrasions or tiny cut marks on the skin through which the Rickettsia present in the fecal matter enters the human body and spreads infection to different body parts via the  bloodstream.

In some patients after treatment with antibiotics and disappearance of symptoms, the infecting Rickettsia may persist in the body leading to re infection after months or even years. This condition is known as Brill-Zinsser disease. Depending upon the type of Rickettsia, typhus can be of different types namely :

  1. Epidemic typhus:caused by the bacterium R. prowazekii and the disease spreads through bite of body louse.
  2. Endemic typhus caused by R.typhi and the disease spreads through bite of cat or rat flea.
  3. Scrub typhus is caused by O.tsutsugamushi and spreads via bite of human or rodent mites. Usually this disease is included under the spotted fever group.

Treatment

Antibiotics are the mainstay of treatment. Commonly used antibiotics include azithromycin, doxycycline, tetracycline and chloramphenicol. The entire course of antibiotics need to be completed in order to totally eradicate the infection. The typhus vaccine prevents occurrence of the disease.

 

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