Typhus fevers are caused by the rickettsiae bacteria and transmitted by arthropod (e.g. flea, mite, tick) bites. When arthropods bite a victim, they leave the rickettsaie bacteria behind. Scratching the bite opens the skin to the bacteria, allowing them to enter the bloodstream. Within the blood stream, the bacteria grow and replicate.
Different arthropods carry specific rickettsaie bacteria for each type of typhus. Typhus symptoms vary slightly by type. The most common symptoms are universal, affecting nearly all typhus patients.
Treatment focuses on using antibiotic medication to stop the infection. Untreated typhus can lead to serious complications and be potentially fatal. Prevention of typhus is easier than treatment. Methods of prevention focus on destroying or avoiding arthropod infestations.
Types of typhus and carriers:
- epidemic/louse-borne typhus (caused by Rickettsia prowazekii) carried by the body-louse
- murine typhus (caused by R. typhi) carried by the rat or cat flea
- scrub typhus (caused by Orientia tsutsugamushi) carried by mites
Global distribution of typhus:
- epidemic/louse-borne: global (focused in areas of high population and poor sanitation, where conditions are best for lice)
- murine typhus: global
- scrub typhus: common in Asia, Australia, Papua New Guinea, and the Pacific Islands
Carrier bites are loaded with the bacteria. When the bites are scratched, they allow the bacteria into the bloodstream. The bacteria grow within the bloodstream, increasing over time.
Symptoms vary slightly by the type of typhus.
Common symptoms of typhus include:
- high fever
Rare symptoms of epidemic typhus include stupor and seeming out of touch with reality.
If you suspect that you have typhus, your doctor will ask about your symptoms and your medical history, including any travel or bites you may have received. To help with the diagnosis, tell your doctor if you:
- are living in a crowded environment
- know of a typhus outbreak in your community
- have a history of travel
Diagnosis is difficult because symptoms are common to other diseases, including:
- dengue (breakbone fever)
- malaria (infectious disease spread by mosquitos)
- brucellosis (infectious disease caused by the brucella bacteria)
Diagnostic tests for the presence of typhus include:
- Western blot (test to identify presence of typhus bacteria)
- immunofluorescence test (using fluorescent dyes to detect typhus in sputum samples)
- blood test (results can indicate the presence of infection)
Antibiotics most commonly used to treat typhus include:
- doxycycline (preferred treatment)
- cholramphenicol (option for those not pregnant or breastfeeding)
- ciprofloxacin (used for those who are unable to take doxycycline)
Common complications of typhus include:
- hepatitis (infection of the liver)
- gastrointestinal hemorrhage (bleeding inside the intestines)
- hypovolaemia (decrease in blood volume)
The mortality rate for untreated typhus is 15 percent (Mazumder, et al., 2009). People who are most at risk of dying are generally those in poor, unsanitary, and crowded conditions. Many are unable to afford adequate and prompt treatment.
Patients with underlying diseases (diabetes mellititus, alcoholism, chronic renal disorders, etc.) have a high risk of mortality. Delayed treatment and misdiagnosis can lead to a more severe case of typhus. Those who receive prompt and correct treatment have a good chance for a successful recovery.
During the Second World War, a vaccine was created to prevent epidemic typhus. However, the dwindling number of cases has stopped the manufacture of the vaccine. The easiest way to prevent typhus is by avoiding the insects that spread it.
Suggestions for prevention of typhus include:
- maintaining personal hygiene (helps guard against lice carrying the disease)
- controlling the rodent population (rodents are known to carry arthropods)
- avoiding places where exposure has occurred (typhus has been responsible for epidemics and outbreaks)
- chemoprophylaxis with doxycycline (used as a preventative only in those at high risk, such as those on humanitarian campaigns in areas with extreme poverty and little or no sanitation)
Typhus has been seen recently in some European countries. In the past few years, Germany has seen several cases in returning travelers. These are surprising cases because typhus is rarely seen in countries with proper sanitation and pest control.