However, the patient did not respond PD-1/PD-L1 inhibitor clinical trial to this treatment and fell into acute respiratory distress syndrome (Figure 1B) as early as 4 hours after we started therapy, and was sustained on a ventilator in the intensive care unit. At the time of entry into the intensive care unit, PaO2/FIO2 was 107, CK and CK-MB were within normal range, and BNP was 29.8 pg/mL. Echocardiography showed normal left ventricular function, normal wall movement,

and no dilatation of the inferior vena cava diameter. Because he did not present any respiratory symptoms such as cough and sputum, we were not able to collect a sputum sample for a bacterial culture. Blood samples obtained at the time of admission were examined for dengue, leptospirosis, and rickettsiosis at the National Institute for Infectious Diseases (NIID). On the third day of admission, we received an interim report from the NIID

that Rickettsia 17 kDa antigen[3] and citrate synthase gene[7, 8] (gltA) were detected in nested-PCR analysis, whereas Orientia tsutsugamushi (56 kDa)[9] was not. Considering the possibility of both typhus and spotted fever bio-groups, we stopped ceftriaxone and switched to ciprofloxacin injections (200 mg twice a day, dosage adjusted for renal dysfunction). His Androgen Receptor Antagonist price general and respiratory conditions gradually improved, and the patient was extubated on the sixth day of admission. Thereafter, he was treated with oral minocycline (100 mg twice a day) alone for 14 days. Finally, the sequences of two rickettsial genes, 17 kDa antigen (434 bp) and gltA (381 bp), detected by nested-PCR were identified as Rickettsia typhi Wilmington (NC006142) with 100% homology, whereas the PCR findings for dengue virus and Leptospira were negative, as were findings for the NS-1 antigen of the dengue Molecular motor virus, the anti-dengue virus specific-IgM antibody, and anti-leptospiral antibodies against 15 serovars, as shown in microscopic

agglutination test results. Unfortunately, we did not store the patient’s serum collected during the recovery phase and did not evaluate serological test results to confirm the diagnosis of murine typhus. However, we carefully performed nested-PCR for increased sensitivity, and targeted multiple gene fragments and sequencing. These results were considered to be reliable for the diagnosis of murine typhus. When febrile patients with a recent travel history are examined, it is important to consider malaria, dengue, mononucleosis, rickettsiosis, and typhoid/paratyphoid, whereas malaria, in particular, should be differentiated because of the high risk of mortality.