Life-threatening Scrub Typhus with Hemophagocytosis and Acute Respiratory Distress Syndrome in an Infant

Abstract

Scrub typhus is a rickettsial disease, caused by Orientia tsutsugamushi, which is transmitted via the bite of a chigger. This disease is one of the most important infectious diseases in the Asia-Pacific area; however, a severe infant case has not yet been reported. Here, we present the case of an 8-month-old boy with scrub typhus accompanied by hemophagocytic lymphohistiocytosis (HLH). His rapid course was complicated by acute respiratory distress syndrome (ARDS), status epilepticus and disseminated intravascular coagulation (DIC). He recovered after clarithromycin therapy and intensive supportive care. Although being extremely rare, scrub typhus can be life-threatening in an infant; therefore, physicians in endemic countries should be aware of the necessity for early recognition and prompt treatment of suspected cases.

Status epilepticus in scrub typhus

“…This is the first comprehensive report of SE in scrub typhus. There are only two case reports describing SE in spotted fever and scrub typhus . A 61‐year‐old man with fever and multi‐organ failure developed SE while he was receiving meropenem and vancomycin.…”

“…In another report, scrub typhus resulted in hemophagocytic lymphohistiocytosis in an 8‐month‐old baby who developed acute respiratory distress syndrome, SE, and disseminated intravascular coagulation. The infant improved following erythromycin therapy . In a study on CNS involvement in scrub typhus, 8 of 37 patients had SE, but details of SE were not mentioned .…”

“…In scrub typhus, seizures have been reported in 6.3–21.6% of patients . In the available medical literature there are only few case reports of status epilepticus (SE) in scrub typhus . In developing countries, CNS infections remain the predominant cause of SE, with poor prognosis .…”

Scrub typhus, acute respiratory distress, and hemophagocytic lymphohistiocytosis

“…Secondary HLH is diagnosed using the following clinical criteria developed by the HLH Study Group of the Histiocyte Society; having five out of eight of the following: (1) fever, (2) splenomegaly, (3) cytopenia (affecting 2 cell lineages), (4) hypertriglyceridemia and/or hypofibrinogenemia, (5) hemophagocytosis in the bone marrow, spleen, or lymph nodes, (6) low or absent natural killer cell cytotoxicity, (7) hyperferritinemia, (8) elevated soluble CD25. 2 In PubMed there are at least 12 papers describing cases of HLH in patients with scrub typhus (search strategy: (haemophagocytic, or haemophagocytosis, or hemophagocytosis, or hemophagocytic, or erythrophagocytosis, or macrophage activation syndrome) AND (scrub typhus OR tsutsugamushi OR orientia)), and ARDS was described in at least four of them, [3][4][5][6] and in one case was fatal. 6 In PubMed there are at least 30 papers describing patients with scrub typhus and ARDS (search strategy: (ARDS OR acute respiratory distress syndrome OR acute respiratory failure) AND (scrub typhus OR tsutsugamushi OR orientia)), and many of them were also complicated by liver failure, multiorgan failure, and disseminated intravascular coagulation (DIC); anemia and thrombocytopenia were very often reported.…”

“…Strangely enough, only in a few papers was a diagnosis of HLH considered in that setting. 3,5,7 HLH is a life-threatening clinical syndrome. Liver involvement is more frequent in pediatric cases, but may be present in adults with variable levels of transaminases up to signs of acute liver failure and coagulopathy.…”