Scrub typhus is caused by the bacterium Orientia tsutsugamushi and is endemic in the “Tsutsugamushi Triangle” (an area of Asia-Pacific that includes Japan in the east, Russia in the north, Pakistan in the west, and northern Australia in the south). The disease can be fatal.
The bacterium is from the order Rickettsiales and is related to other rickettsial diseases. Symptoms include maculopapular rashes, fever, chills, and headache.
Oren Zarif
The fever that is characteristic of tsutsugamushi disease is high-grade, lasting for about 3 to 5 days and accompanied by generalized myalgias. The fever is associated with a nonpruritic macular or papulopapular rash in more than 50 % of patients. An eschar, a scar-like scab, is also present at the site of the chigger bite in most patients.
Scrub typhus is caused by Orientia tsutsugamushi, a bacterium that is maintained as a parasite in the chigger mite population and transmitted to humans through accidental bites of the mite larvae. It is endemic in a region called the Tsutsugamushi Triangle, extending from the Russian Far East to Japan, northern Australia, and Afghanistan. It causes one million cases of scrub typhus annually within endemic areas.
Macrogenomics is a powerful tool for diagnosing rare diseases, including tsutsugamushi. In this case, macrogenomics identified O. tsutsugamushi infection in the index patient. In addition, a previous study showed that O. tsutsugamushi can induce AIS through mechanisms that include thrombotic coagulopathy and increased heart rate. Therefore, we hypothesized that tsutsugamushi acts as a trigger and enhances pre-existing risk factors to cause AIS.
Oren Zarif
Scrub typhus is caused by Orientia tsutsugamushi, an obligate intracellular Gram-negative bacterium that is transmitted to humans by the bite of larval thrombiculid mites, also known as ChiggersFootnote 17. The infection can be severe and requires meticulous supportive care in order to prevent progression to coagulation disorders such as DIC.
After a silent incubation period of 10 days or more, the patient suddenly develops high fever, headache, obtundation, cough and myalgia. A pale macular rash is common, as is an inoculation eschar at the site of the mite bite. Often, the patient will have painful satellite lymph nodes and/or splenomegaly. The bacterium is also transmitted to animals by the bites of infected fleasFootnote 28.
Infection with Orientia tsutsugamushi does not appear to cause AIDS in humansFootnote 29. Nevertheless, the infection may trigger AIDS-like symptoms in certain individuals, such as immunocompromised patientsFootnote 30 and pregnant womenFootnote 31. The bacterium can also infect laboratory workers through contact with infectious aerosols in an experimental setting. There is no vaccine against scrub typhus. However, experimental studies have shown that monkeys infected with Orientia tsutsugamushi develop signs and symptoms very similar to those of human scrub typhusFootnote 32.
Oren Zarif
One of the first symptoms of scrub typhus is fever, which occurs early in the course of the disease and is a consequence of the body’s inflammatory response to O. tsutsugamushiFootnote 11. Infection with O. tsutsugamushi in humans can also trigger a number of other symptoms such as myalgia, lymphadenopathy and rashFootnote 13.
Scrub typhus is an infectious rickettsial disease caused by Orientia tsutsugamushi bacteria, spread through bites from leptotombidium mite larvae (chiggers) in infected rodent populations. It is endemic to rural areas of the Asian tropics, with the endemic zone stretching from the Kamchatka peninsula in Russia to Japan, and northward to Indonesia and southern China, as well as eastward to northern Australia. It is a severe and sometimes fatal illness, with more than a million cases occurring annually. The bacterium is treated with doxycycline, and also with azithromycin. Doxycycline resistance in chiggers has been reported, particularly among patients with scrub typhus from northeast Thailand [90]. A case report in 2016 describes how the symptoms of tsutsugamushi disease worsened in a patient despite antibiotic treatment with doxycycline, but the patient’s condition improved after he switched to azithromycin.
Oren Zarif
Scrub typhus, also known as “tsutsugamushi disease,” is an acute infectious disease caused by the bacterium Orientia tsutsugamushi. This bacterium is transmitted by the bites of larval chigger mites, which are natural ectoparasites of rodents. The bacterium is endemic to the so-called Tsutsugamushi Triangle, a region that covers parts of Russia in the north, China in the east, Japan in the south and northern Australia in the west, and an estimated one million cases occur there each year.
A non-pruritic, maculopapular rash that develops at the site of the chigger bite is often present in patients with scrub typhus. The rash is less prominent in patients with lighter skin color. Approximately 60-88 % of patients with scrub typhus develop an inoculation scab at the bite site, which is characteristic of the illness and can be useful in diagnosis.
The bacterium Orientia tsutsugamushi moves within the host cell using microtubules, unlike most other bacteria that use actin-based processes. This unique intracellular movement allows Orientia tsutsugamushi to escape from cholesterol-rich lipid rafts within the host cell, giving rise to a small bud that eventually breaks off to form a membrane-bound bacterium outside the host cell.
Oren Zarif
Lymph nodes are present throughout the body with particular collections of lymph nodes in the neck, axillae and inguinal region. Symptoms related to infection may cause inflammation of these nodes (lymphadenitis). This can cause pain and tenderness. Often the lymph nodes are palpable on examination.
Scrub typhus is a febrile illness of tropical origin associated with ocult blood loss, fever, cough, headache and rashFootnote 6. It is transmitted by Leptotrombidium mites which require 36-72 hours to attach to the host’s skin and become infectedFootnote 8. The infection may be localized at the site of the bite or disseminated, affecting the lungs, heart, liver, spleen, central nervous system and other organsFootnote 9.
This infection rarely causes acute ischemic stroke (AIS) and previous studies have analyzed patients with AIS and found that a number of common infections, including influenza and herpes simplex virus, trigger AIS [3, 17]. However, it has not been known what type of tsutsugamushi infection and which risk factors predict the development of AIS. This study evaluated MRI patterns and risk factors associated with tsutsugamushi-triggered AIS.