Scrub typhus is a neglected tropical disease; and, a leading cause of undifferentiated febrile illness in the areas of tsutsugamushi triangle caused by Orientia tsutsugamushi. Imported cases of scrub typhus was reported in those travelers coming back from tsutsugamushi triangle [8]. The prevalence of scrub typhus or the infectivity of mite/tick may be related with ecology; a sudden upsurge in scrub typhus cases was reported after the 2015 earthquake in Nepal [4].

Clinical presentation may be typical [9] or rare presentation if early diagnosis could not get or the patient came late; thus, complicated by ARDS [10], multiorgan failure and thrombocytopenia [11]. It may presented with acute abdomen, septic shock and DIC rarely [12]. This patient came to hospital late; he had fever for almost 7 days- septicemic state. Thus, he had septic shock, ARDS, acute kidney injury, thrombocytopenia, hypoalbuminemia and transaminitis.

In 2017, serologic and molecular surveillance of 152 suspected scrub typhus patients in central region of Myanmar revealed Orientia tsutsugamushi of genotypic heterogeneity. In addition, potential co-infection with severe fever with thrombocytopenia syndrome virus was observed in 5 (3.3%) patients. Both scrub typhus and severe fever with thrombocytopenia syndrome were endemic in Myanmar [13]. Therefore the presence of thrombocytopenia in this patient supported their findings. Eschar was seen in 95% of cases. Eschar is pathognomonic; the underlying erythema may varies with ethnicity/ skin color- more prominent in white skin; multiple eschars may be seen [14].

Rickettsial infections are widespread in Myanmar; recent serological study on 700 leftover blood samples from primary care clinics and hospitals of central and northern regions of Myanmar revealed that IgG seroprevalence for scrub typhus was nearly 20%, for murine typhus was 5% and for spotted fever group was 3% [15]. This patient came back from Delta area, southern regions of Myanmar; therefore, the seroprevalence of rickettsial infections may be wide spread.

History of travelling or exposure along with tick bite gave clue to diagnosis if the patient was fully conscious; otherwise, physical examination was extremely important. Eschar is the single most useful diagnostic clue; pathognomonic. The eschar begins as a small, painless papule at the site bitten by chigger and develops during the 6 to 18days (median 10 days) incubation period. It enlarges, undergoes central necrosis with a black crust; the border is surrounded by reddish erythema.

In endemic area, the tick may be attached to skin of patients. The common presentations were fever, headache, myalgia, and non-specific malaise; hearing loss concurrent with fever was seen in one third of cases. Conjunctival suffusion/congestion was remarkable as seen in this patient. Generalized lymphadenopathy is seen in majority of cases. Cough sometimes accompanied by infiltrates on the chest radiograph is one of the commonest features; common findings in CT chest are ground glass opacity, mediastinal lymphadenopathy and inter-lobular septal thickening [16]. In chest radiograph of this patient, multiple ground glass opacities were seen. However, CT chest was not done in this case. The serious complications are pneumonitis, myocarditis, meningoencephalitis, acute renal failure, gastrointestinal bleeding and ARDS. Cases with multi-organ failure and immune thrombocytopenia were reported [11]. In this patient, hypoalbuminemia and transaminitis were present in addition to septic shock, ARDS, acute kidney injury and thrombocytopenia. The study by Aung Thu reported hypoproteinaemia, elevation of SGOT, SGPT, and alkaline phosphatase in cases of scrub typhus in Myanmar. Thus, having hypoalbuminemia and transaminitis in this patient confirmed the report.

Diagnosis of scrub typhus is challenging as its symptoms mimic with other acute febrile illnesses. Several methods are used for diagnosis of scrub typhus: enzyme-linked immunosorbent assay (ELISA), immunofluorescence assay (IFA), immunochromatographic test (ICT), Weil–Felix, polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP). PCR based methods are good for early-stage diagnosis with higher specificity and sensitivity; however, it is less applicable in circumstances of scrub typhus due to the variegated genetic makeup of Orientia tsutsugamushi among its serotypes [17]. In resource limited setting, all the diagnostic tests are difficult. In this case, the diagnosis was mainly based on eschar, positive rapid test for scrub typhus IgM and exclusion of other common causes of fever of antimicrobial therapy, the treatment of choice is oral tetracycline 500 mg four times daily or oral doxycycline 100 mg twice daily for 7 days. The alternative is oral chloramphenicol 500 mg QID for 7 days. Oral ciprofloxacin or rifampicin can also be used. In severe cases, parenteral doxycycline/parenteral chloramphenicol (50-75 mg/kg/day) should be given. One of efficacy and safety studies on scrub typhus revealed that clarithromycin may be safe [18]. The mortality rate is 50 % without treatment.