Scrub typhus in pregnancy presenting with permanent hearing loss: A case report
Running title: scrub typhus and hearing loss
Abstract
Introduction: Scrub typhus can present with audiological symptoms.
Case: A pregnant mother presented with persistent fever, pneumonia and hearing loss. Investigation showed positive serology for scrub typhus.
Conclusion: Clinicians must be aware of audiological presentations in scrub typhus. Possibly, permanent hearing loss was due to meningoencephalitis and hormone induced immunomodulation.
Keywords: hearing loss; pregnancy; scrub typhus.
Introduction
Scrub typhus is a mite borne infectious disease caused by Orientia tsutsugamushi . The vector and reservoir for this disease is the larval trombiculid mites also known as chiggers. The southern belt of Bhutan is seasonally endemic to scrub typhus with highest occurrence in farmers.1
The clincal manifestations of this non specific febrile illness are intense headache and myalgia. Some patients develop generalized lymphadenopathy, macular or maculopapular non pruritic rashes and an eschar. Rare and atypical presentations such as acute reversible auditory symptoms like hearing loss, tinnitus and otalgia have been reported. 2,3 Possible mechanism for such presentations are immune mediated vasculitis leading to cochlear neuroinflammation resulting from exaggerated Th1 cellular immune response. 3,4 The severity of infection can vary from mild symptoms to severe multiorgan failure. Mortality rates were higher in those developing pneumonia, delirium, myocarditis and elderly population. 5,6
The clinical diagnosis accuracy remains non specific due to largely overlapping symptoms seen in other tropical infections like dengue, malaria and leptospirosis. Most patients develop thrombocytopenia, elevated hepatic enzymes and deranged renal functions. Leucopenia or leucocytosis may develop but most patients present normal total leucocyte count. 7
Since the audiological symptoms related to scrub typhus discussed in the literature were transient or reversible, we hereby present this case with permanent hearing loss in a pregnant woman following scrub typhus infection.
Case presentation
A previously healthy 39 year old G6P5 farmer at 34 weeks gestation was referred from Punakha District Hospital with 5 days history of fever, headache, generalized bodyache, shortness of breath and cough. There were no audiological, gastrointestinal or urinary symptoms. On admission to the maternity ward, she was ill looking but conscious with tachypnea, high grade fever and pallor. There was no cervical lymphadenopathy, icterus, body rashes, eschar or ear infection. Her respiratory rate was 26-30/min, pulse rate of 120 beats per minute and blood pressure of 110/70 mm Hg. Cardiac auscultation revealed ejection systolic murmur at left lower sternal edge which was probably due to hyperdynamic circulation in anemia.. There was coarse crepitation noted in bilateral lung fields. Abdominal examination revealed no hepatosplenomegaly. Cardiotocograph was reassuring.
Presumptive diagnosis of community acquired pneumonia was made and empirical treatment started with intravenous ceftriaxone and oral erythromycin. Antenatal corticosteroid was administered as per the hospital protocol. One unit of packed red cell was transfused.
Laboratory investigation reports showed moderate anemia (Hb 7.9gm%), raised C-reactive protein (19.9mg/l), and mild transaminitis. Renal function was normal. Sputum culture showed Klebsiella pneumoniaewhich was sensitive to Ciprofloxacin and resistant to Ceftriaxone. Blood and urine culture were sterile. Dengue serology and malaria parasite smear were negative. Chest X ray (Figure 1) showed features suggestive of pneumonia. Echocardiogram was done to rule out cardiac causes of febrile illness and the findings were normal.