In endemic areas, diagnosis is generally made on clinical grounds alone. However, overshadowing of the diagnosis is quite often as the clinical symptoms overlap with other infectious diseases such as dengue fever, paratyphoid, and pyrexia of unknown origin (PUO). If the eschar can be identified, it is quite diagnostic of<unk> , but this can be unreliable on dark skin, and moreover, the site of eschar which is usually where the mite bites is often located in covered areas. Unless it is actively searched for, the eschar can easily be missed. History of mite bite is often absent since the bite does not inflict pain and the mites are almost too small to be seen by the naked eye. Usually,<unk>  is often labelled as PUO in remote endemic areas, since blood culture is often negative, yet it can be treated effectively with chloramphenicol. Where doubt exists, the diagnosis may be confirmed by a laboratory test such as serology. Again, this is often unavailable in most endemic areas, since the serological test involved is not included in the routine screening tests for PUO, especially in Burma (Myanmar). The choice of laboratory test is not straightforward, and all currently available tests have their limitations. The cheapest and most easily available serological test is the Weil-Felix test, but this is notoriously unreliable. The gold standard is indirect immunofluorescence, but the main limitation of this method is the availability of fluorescent microscopes, which are not often available in resource-poor settings where<unk>  is endemic. Indirect immunoperoxidase, a modification of the standard IFA method, can be used with a light microscope, and the results of these tests are comparable to those from IFA. Rapid bedside kits have been described that produce a result within one hour, but the availability of these tests is severely limited by their cost. Serological methods are most reliable when a four-fold rise in antibody titre is found. If the patient is from a nonendemic area, then diagnosis can be made from a single acute serum sample. In patients from endemic areas, this is not possible because antibodies may be found in up to 18% of healthy individuals. Other methods include culture and polymerase chain reaction, but these are not routinely available and the results do not always correlate with serological testing, and are affected by prior antibiotic treatment. The currently available diagnostic methods have been summarised.
Scrub typhus
Murine typhus
Plague 
Flying squirrel typhus
Haverhill fever
Tomato fever
Rat-bite fever
North Asian tick typhus