|Year : 2016 | Volume
| Issue : 2 | Page : 244-246
Tricky typhus ticks two: A report of two sisters from North India presenting with acute respiratory distress syndrome due to scrub typhus
R Pai1, R Chaudhry2, N Gupta1, PB Sryma1, A Biswas1, AB Dey1
1 Department of Medicine, All India Institute of Medical Sciences, New Delhi, India
2 Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
|Date of Submission||01-Jun-2015|
|Date of Acceptance||04-Dec-2015|
|Date of Web Publication||14-Apr-2016|
Department of Microbiology, All India Institute of Medical Sciences, New Delhi
Source of Support: None, Conflict of Interest: None
Scrub typhus is emerging as an important cause of acute febrile illness in Northern India. This is a report of two sisters presenting concurrently with acute respiratory distress syndrome. A diagnosis of scrub typhus was made in both the patients, and they were successfully treated with doxycycline.
Keywords: Fever/aetiology, Orientia tsutsugamushi, scrub typhus/diagnosis, scrub typhus/drug therapy, scrub typhus/epidemiology
|How to cite this article:|
Pai R, Chaudhry R, Gupta N, Sryma P B, Biswas A, Dey A B. Tricky typhus ticks two: A report of two sisters from North India presenting with acute respiratory distress syndrome due to scrub typhus. Indian J Med Microbiol 2016;34:244-6
|How to cite this URL:|
Pai R, Chaudhry R, Gupta N, Sryma P B, Biswas A, Dey A B. Tricky typhus ticks two: A report of two sisters from North India presenting with acute respiratory distress syndrome due to scrub typhus. Indian J Med Microbiol [serial online] 2016 [cited 2019 Sep 19];34:244-6. Available from: http://www.ijmm.org/text.asp?2016/34/2/244/176847
| ~ Introduction|| |
Scrub typhus is a rickettsial disease caused by the bite of larval stage of trombiculid mite (chiggers), which are usually found in the areas of heavy vegetation. It is a febrile illness where classical case description includes lymphadenopathy, rash and eschar. Serology is the mainstay in the diagnosis of scrub typhus.  Although immunofluorescence assay (IFA) is considered as the gold standard, alternative serological techniques such as enzyme-linked immunosorbent assay (ELISA) and rapid flow assay (RFA) can be used in the absence of gold standard. IgM ELISA is a very commonly used modality for diagnosis, but the high number of false positives reported in an Indian study (specificity - 73%) precludes it from being the single diagnostic modality of choice.  RFA can be highly useful as a point of care screening test in developing settings as evidenced by the high sensitivity of 93.9% reported in a Chinese study.  Molecular techniques such as polymerase chain reaction (PCR) assay, as of now are only useful as a confirmatory test as most studies show a very high specificity, but an equally poor sensitivity. Azithromycin and doxycycline have both been shown to be effective in the treatment of scrub typhus, but the resolution of symptoms has shown to be faster in doxycycline compared to azithromycin. 
| ~ Case Report|| |
A 15-year-old girl (patient A) from Haryana was hospitalised with fever, dry cough and shortness of breath for 10 days. Examination revealed tachypnoea, crackles over lungs, enlarged liver, low oxygen saturation, PaO 2 /FiO 2 -202.8 and bilateral lower-zone interstitial infiltrates in chest X-ray. A diagnosis of mild acute respiratory distress syndrome (ARDS) was made. Her 18-year-old sister (patient B) was hospitalised within a few hours with similar symptoms and signs; and PaO 2 /FiO 2 -178.2. Again, a diagnosis of moderately severe ARDS was made. Both the patients had leucocytosis, thrombocytopenia and deranged liver functions [Table 1]. Pending microbiological diagnosis and considering the severity of disease, they were started on third generation cephalosporin and doxycycline to cover both the typical and atypical aetiologies of pneumonia. They were additionally put on noninvasive ventilation (bi-level positive air pressure-expiratory positive airway pressure = 6 cm of H 2 O, inspiratory positive airway pressure = 12 cm of H 2 O). Blood and urine cultures were sterile. Test results for malaria, leptospirosis, dengue and influenza were negative. On detailed epidemiological evaluation, the family resided in a village located in the vicinity of a forest, which was regularly frequented by the sisters for gathering forest produce. Scrub typhus, although initially considered unlikely, was suspected on the 3 rd day of admission. On serological examination, IgM antibodies against scrub typhus derived recombinant r-56 antigens were detected in both the patients by RFA and ELISA. The diagnosis of scrub typhus was further confirmed by IFA with titres of >1/512 in both the patients. A nested PCR technique using conditions described by Furuya et al.,  was also done on whole blood which detected a 483 bp segment of 56 kDa gene in both the patients. By the time laboratory diagnosis was confirmed, the patients were already showing resolution of fever and improvement in oxygenation, as they were empirically started on doxycycline. They were continued on doxycycline 100 mg BD orally until the 7 th day of admission.
| ~ Discussion|| |
Scrub typhus is among the most neglected and under-reported infectious diseases in India. The initial delay in the diagnosis was due to the lack of classical manifestations in both the patients. Even though the presence of eschar has been much talked about for the diagnosis of scrub typhus, it is noteworthy that a very low prevalence of eschars (3-7%) has been noted in South Asian studies.  The concurrent occurrence of a disease with predominant respiratory symptoms usually points to droplet mode of transmission and is rarely diagnosed as a vector-borne disease. Moreover, such a scenario with a diagnosis of scrub typhus has not been reported to the best of our knowledge. The use of azithromycin and/or doxycycline as empirical therapies in the case of respiratory presentations has led to spontaneous recovery of patients without them being tested for scrub typhus. However, in other settings, where doxycycline and azithromycin are not used as empirical therapy, scrub typhus with its various presentations and complication can be fatal (10-15%).  Therefore, there is an urgent need for creating awareness among clinicians and improving diagnostic facilities. Most of the case reports in India are from regions covered with forests: Southern peninsula, North-East and sub-Himalayan region. Very few cases of scrub typhus presenting with ARDS has been reported from the Northern part of India. We report this case to emphasise the need for clinicians to consider emerging infections in unusual clinical settings.
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Conflicts of interest
There are no conflicts of interest.
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