Typhus: Introduction, types, Causes, Symptoms, Diagnosis and Treatment

achaurasiya

7 years ago

Introduction of Typhus

Typhus is a disease caused by bacteria called Rickettsia. Fleas, mites, lice, or ticks transmit it when they bite us. When arthropods carrying around Rickettsia bite, they transmit the bacteria that causes typhus. Scratching the bite further opens the skin and allows the bacteria greater access to the bloodstream. Once in the bloodstream, the bacteria continue to reproduce and grow.

Types

It is of three types

endemic
epidemic
and scrub typhus: It is fully dependent on which species of Rickettsia you are infected with and the involvement of arthropods. Its outbreaks mainly occur in developing countries or in regions of poverty, poor sanitation, and close human contact. Untreated typhus can lead to serious complications, and it’s potentially fatal. It’s important to see your physician if you suspect that you may have typhus.

Cause

Typhus is not transmitted from person to person like a cold or the flu. There are three different types of typhus, and each type is caused by a different type of bacterium and transmitted by a different type of arthropod.

Epidemic/louse-borne typhus

This type is caused by Rickettsia prowazekii and carried by the body louse, and possibly by ticks as well. It is worldwide but is typically found in areas of high population and poor sanitation, where conditions promote lice infestation.

Endemic typhus

Also known as murine typhus, this type is caused by Rickettsia typhi and is carried by the rat or cat flea. It can also be found worldwide.

Scrub typhus

This type is caused by Orientia tsutsugamushi and carried by mites in their larval stage when they are chiggers. It is more commonly found in Asia, Australia, Papua New Guinea, and the Pacific Islands. The louse, flea, tick, or mite becomes a carrier of the bacteria when they feed on the blood of an infected person (epidemic type) or an infected rodent (any of the three typhus forms mentioned above). If you come in contact with these bacterium-carrying arthropods (for example, by sleeping on bed sheets infested with lice), you can become infected in a couple of ways. The bacteria, in addition to being transmitted through your skin by their bites, can also be transmitted through their feces. If you scratch the skin over an area where lice or mites have been feeding, the bacteria in their feces can enter your bloodstream through the tiny wounds on your skin.

Symptoms

Common to all types:

headache
fever
chills
rash

Symptoms of epidemic typhus

usually appear suddenly and include:

severe headache
high fever (above 102.2°F)
rash that begins on the back or chest and spreads
confusion
stupor and seeming out of touch with reality
low blood pressure (hypotension)
eye sensitivity to bright lights
severe muscle pain

The symptoms of endemic typhus

last for 10 to 12 days and are very similar to the symptoms of this type but are usually less severe. They include:

dry cough
nausea and vomiting
diarrhea
Symptoms seen in people with scrub typhus include:
swollen lymph nodes
tiredness
red lesion or sore on the skin at the site of the bite
cough
rash

The incubation period for the disease is five to 14 days, on average. This means that symptoms won’t usually appear for up to five to 14 days after you are bitten. Travelers who get typhus while traveling abroad may not experience symptoms until they are back home. This is why it is important to tell your physician (doctor)about any recent trips if you have any of the above symptoms.

Your responsibility towards Diagnosis:

tell your doctor if you:

are living in a crowded environment

have traveled abroad know of a this infection

the outbreak in your community recently

Diagnosis is difficult because symptoms are common to other infectious diseases, like:

dengue
malaria
brucellosis

Lab Diagnosis

skin biopsy
Western blot
Serological test-This Scrub Typhus Detect™ IgM Rapid Test is a qualitative, membrane-based immunoassay for the detection of IgM to members of O. tsutsugamushi in human serum, plasma, or blood. The membrane is pre-coated with a mixture of novel recombinants (representing several geographical isolates) on the test line region and appropriate control antigen on the control line region. During testing, the sample reacts with the dye conjugate (anti-human IgM colloidal gold conjugate) which has been pre-coated in the test device. The mixture then migrates upward on the membrane chromatographically by capillary action to react with ST-derived recombinant antigens on the membrane and generates a red band or line. The presence of this red line indicates a positive result, while its absence indicates a negative result. Independent of the presence or absence of antibodies to scrub typhus antigens, a red line or band at the control line region will always appear when the sera-gold migrates to the immobilized control region. The presence of this red band verifies for sufficient sample volume and proper flow of reagents.

Procedure of Rapid Test

Open the pouch
Put 10 µl of serum or whole blood at the sample pad ( in the area beneath the arrow) of the strip.
Placed the test strip in a test tube or a plastic well (holds 150–
200 μL of liquid).
After that put three drops of chase buffer.
Read the result for up to 15 minutes.

Observation

Observe for pink or red line or band.

Result and interpretation of Scrub typhus Rapid Test

Only on the band at control region: Test negative
Both bands at the control and test region: Test positive
No band or band only at test region: Test invalid ( repeat the test with new strip)
Our test is positive as shown above picture.

Treatment

Choice of drugs

Doxycycline
Chloramphenicol (for pregnant or breastfeeding)
Ciprofloxacin (used for adults who are unable to take doxycycline)