Scrub typhus is a form of typhus caused by Orienta (formerly Rickettsia) tsutsugamushi and carried by mites.The disease is transmitted to human upon being bitten by mites. Scratching the skin opens the bite which allows the bacteria to enter the blood stream. Once in the blood, it reproduces and grows. Orienta tsustugamushi bacteria differ from rickettsia based on cell-wall structure and genetic composition.
The name is associated with a type of vegetation which harbors the vector. These carriers are larval stage mites called chiggers. Wild rats serve as the natural reservoir for chiggers. Scrub Typhus is not transmitted from one person to another. This disease can be acquired year around in tropical regions. The common symptoms that are associated with scrub typhus are severe headache, fever, chills, cough, muscle pain, rash and gastrointestinal symptoms.
The process of diagnosis is based on symptoms and medical history. The doctor requires information on living in a crowded environment, any outbreak in the area of residence or while traveling. The diagnosis process is a bit difficult because some symptoms are common to other diseases. These include dengue, malaria and brucellosis.
There is different diagnosis tests carried out to determine the presence of scrub typhus. Skin biopsy involves testing the sample of the affected skin in a lab. Rapid immunochromatographic test is carried out too determine presence of IgM and IgG. The immunofluorescence test uses fluorescent dyes to detect typhus in samples of sputum. This is a thick fluid or mucus found in the lungs and breathing passages. Blood test results are also used to indicate presence of infection. Tests include dot immuno-assay, polymerase assay, Weil-Felix OX-K strain agglutination and Rapid diagnostic reagent for scrub typhus.
Patients with scrub typhus may reveal the following:
- Early lymphopenia with late lymphocytosis.
- Decreased CD4:CD8 Lymphocyte ratio
- Hematologic manifestations which may be confused with dengue infection
- Elevated transaminase levels
Chloramphenicol was the first drug used to treat scrub typhus in common endemic regions. Doxycycline is now the drug choice for this illness. Ciprofloxacin is used for those people who are unable to take doxycycline.
The easiest way to prevent typhus is to avoid insects that spread the bacteria. This is because the shrinking number of typhus cases has stopped the manufacture of vaccines.
- Maintaining a clean home helps is keeping away mice which carry the disease
- It is also good to check oneself for any mites especially after agricultural exposure in rice fields
- Typhus can also be prevented by controlling the rodent population known to carry arthropods
- It can also be prevented by avoiding regions where typhus exposure has occurred due to poor sanitation.
- The disease can also be prevented using chiggers and insect repellent
- It’s recommended to perform routine examinations for mites
- Protective clothing should be won when traveling in areas with typhus outbreaks
- Biological control can also be applied by keeping cats who will keep rats away
- It is also recommended to clean bushes around homes to keep insects away
- Environmental insecticides are also used for short-term vector reduction
Early treatment with antibiotics is very effective with minimal relapse cases. Delayed diagnosis and treatment can lead to more severe cases of scrub typhus. Typhus epidemics are common in poor, unsanitary and crowded areas. Mortality rates are high among old and malnourished individuals. With appropriate antibiotic treatment, mortality from scrub typhus is quite rare. However, the disease contraction can be avoided by keeping away from mites.