Typhus, also known as typhus fever, are infectious diseases caused by the bacteria Rickettsia typhi and Rickettsia prowazekii.
The condition occurs when the bacteria is transferred to humans via vectors such as fleas or lice that acquired it from animals like rats, opossums, cats, and raccoons.
Scratching the bite of the bite on the skin gives the bacteria greater access to the bloodstream, where they continue to reproduce and grow.
The three different types of typhus are:
- Epidemic typhus
- Endemic typhus
- Scrub typhus
Each kind of typhus is dependent on the vector that carries it.
Typhus outbreaks typically occur in developing countries or areas of extreme poverty, close human contact, and poor sanitation.
Endemic typhus is common in tropical and subtropical regions of the world. While scrub typhus usually occurs in Japan, Southeast Asia, and Northern Australia.
Typhus can have severe complications that could be fatal if left untreated. There is no vaccine available to treat the disease. Treatment is by the use of antibiotics.
History of Typhus
One of the first authentic descriptions was the late 15th century during the Spanish siege of Granada, which led to the death of thousands of people. The disease was described to have symptoms such as sores, rashes, and hallucinations.
Over time, the disease was termed goal fever or jail fever. The English authorities in 1759 estimated that about 23% of prisoners in English jails died of jail fever annually.
The disease was named typhus is 1760, a derivative of the Greek word for smoke or stupor, owing to how the disease causes delirium in infected people. Over the centuries, typhus endemics raged all over Europe due to poor living conditions caused by wars.
In the early 19th century, there were over 100,000 deaths in Ireland, while in the United States, typhus outbreaks were recorded in Baltimore, Concord, Washington D.C and Philadelphia.
The cause epidemic typhus was discovered by a Brazilian doctor, Henrique de Rocha Lima, while researching the disease in Germany. The disease was notably worse during and after World War, causing over 3 million deaths.
Although a vaccine was developed before the second world war to combat the disease, typhus epidemics continued to spread, especially in the concentration camps during the Holocaust.
Dichlorodiphenyltrichloroethane (DDT) was eventually used to kill lice at the end of the second world war, and only a few epidemics, usually in the Middle East, Asia, Eastern Europe, and Africa, have occurred since then.
Endemic typhus, on the other hand, still seems to be on the increase, although it is now recognized and correctly diagnosed in the US.
For instance, there were 53 diagnosed cases of endemic (murine) typhus in Travis County, Texas. Also, the disease was reported in Galveston County, Texas, in 2018.
Types of Typhus
There are three different kinds of typhus, and each is caused by a different bacterium and transferred by a different vector.
This type of typhus caused by the bacterium, Rickettsia prowazekii, and transmitted by the body louse and possibly by ticks as well. Epidemic typhus can be found all over the world, including in the United States. It is, however, typically found in areas with a high population and poor sanitation.
Also commonly known as murine typhus, this type is caused by bacterium Rickettsia typhi and is carried by cat fleas and rat fleas. Endemic typhus is a global disease and can be found amongst people who are in close contact with rats.
Areas, where endemic typhus have been seen recently, are some areas of Texas and southern California, both in the United States
Scrub typhus is caused by Orientia tsutsugamushi, a bacterium carried by larval mites, also known as chiggers. This type of typhus is typically found in the Pacific Islands, Australia, Asia, and Papua New Guinea. It is also known as tsutsugamushi disease.
Fleas, lice, mites, and ticks become vectors of the bacteria when they feed on an infected rodent or an infected person.
Close contact with any of these bacterium-carrying arthropods can lead to the development of typhus in a number of ways. Not only can the disease be contracted through the skin from their bites, it can also be transmitted through their fecal matter.
Scratching the area of the skin with their bites can cause the bacteria in their feces to enter your bloodstream through the tiny wounds on the skin.
Signs and Symptoms of Typhus
Symptoms of typhus that are common among all three types include;
Symptoms of epidemic typhus include;
- Low blood pressure
- Severe headache
- High fever
- Rash beginning from the chest or back and spreads
- Severe muscle pain
- Visual sensitivity to bright lights
The symptoms of epidemic typhus usually appear without notice. Symptoms of endemic typhus include. They include;
- Nausea and vomiting
- Dry cough
These symptoms typically last for 10 to 12 days, and are they are similar to the symptoms of epidemic typhus but are generally less severe.
Symptoms of scrub typhus include;
- Sores on the skin at the site of the bite
- Swollen lymph nodes
The incubation period for typhus is usually around 5 to 14 days. This means that symptoms of the disease won’t usually appear for up to 5 to 14 days after a person has been bitten.
Travelers infected with typhus while traveling abroad may not experience symptoms until they are back home.
Diagnosis of typhus can be difficult due to its similarities with other diseases like malaria, brucellosis, and dengue fever. A diagnosis would be performed by using the patient’s medical history and blood tests to check for the presence of the typhus bacteria.
To help with the diagnosis, a patient would have to tell the doctor their living conditions, and if there has been any recent traveling activity.
Other tests for the disease include a skin biopsy to test the rash, and immunofluorescence test to check for typhus antigens in the blood.
The most effective method for all three kinds of typhus is the use of the antibiotic, doxycycline.
A single dose of doxycycline has proven to be effective against epidemic typhus. The antibiotic also works on other strains of typhus. Doxycycline should be taken immediately after the symptoms have been observed, for the best result.
The doctor may recommend another antibiotic such as ciprofloxacin if the patient is allergic to doxycycline.
There is no vaccine available for the prevention of typhus. The most effective means of typhus prevention is basic hygiene. This would include;
- Bathing at least once a day and regular changing of clothes.
- Keep a safe distance from carriers of the disease such as rats, wild cats, and squirrels.
- Proper disposal of food waste and trash.
- Use of insecticides and other methods of insect control in areas with murine typhus.
- Do not let pets share your bed with you.
- Use insect repellants when traveling to areas with typhus.