BACKGROUND: Japanese spotted fever (JSF) mainly occurs in Japan; however, it has been increasingly reported in China. JSF is typically characterized by fever, rash, and eschar, in addition to non-specific symptoms. Yet, reports on the pulmonary indicators in JSF are limited. Herein, we report an unusual case of JSF associated with pleural effusion and pneumonia, in which the pathogen was identified via blood next-generation sequencing (NGS).
METHODS: We report a case of a 33-year-old woman who presented with fever for five days, rash for two days, and myalgia, fatigue, and edema for one day. She had recently been on vacation when an unknown insect bit her. The doctors at the local primary hospital considered a bacterial infection and administered dexamethasone, ceftriaxone, indomethacin, and anti-allergy agents, but the symptoms persisted. A rash without pruritus or pain developed gradually over the entire body and face. We considered rickettsial infection and administered doxycycline and levofloxacin. Metagenomic NGS from blood confirmed the presence of Rickettsia japonica (R. japonica). Abdominal computed tomography revealed bilateral pleural effusion with two atelectasis; patchy shadows with blurred edges, and uniform enhancement in both lower lungs. After several days of treatment, the symptoms and laboratory results improved. A literature review of the epidemiology of R. japonica and JSF in China, characteristics of JSF, and related pulmonary changes, and technology to diagnose JSF is provided.
CONCLUSIONS: JSF has a variety of symptoms and is becoming increasingly popular in China. Clinical doctors need to identify it carefully.

A 71-year-old male had disseminated multiple organ dysfunction syndrome (MODS). Following treatment with cefotaxime and piperacillin-tazobactam, his symptoms have worsened instead. Multiple organ failure caused by Japanese Spotted Fever (JSF) was diagnosed based on metagenomic next-generation sequencing (mNGS), we rapidly treated the patient with doxycycline. Thereafter, his symptoms gradually improved. In this report, we emphasized the importance of rapid microbial diagnostic tools and the early use of tetracyclines for the treatment of JSF.

UNASSIGNED: Rickettsia japonica infection is a rare disease, it is rare to report critical and severe case caused by this disease in Zhejiang Province, China.
UNASSIGNED: We report a patient who initially sought medical attention due to fever and developed coma and convulsions during treatment. The patient did not develop typical eschar and rash. Eventually, the patient needed to be treated in the intensive care unit due to acute respiratory failure.
UNASSIGNED: The patient was diagnosed with Rickettsia japonica bloodstream infection by metagenomic next-generation sequencing (mNGS).
UNASSIGNED: Due to the critical illness, the patient was transferred to the intensive care unit, received doxycycline and other treatments, and rapidly recovered and discharged.
UNASSIGNED: The patient developed a critical illness after being infected with Rickettsia, when the medical history is unclear and clinical symptoms and signs are atypical, it is necessary to use mNGS examination for diagnosis.

UNASSIGNED: Japanese spotted fever (JSF) is a rare disease, caused by Rickettsia japonica; no case has been reported in Zhejiang Province, China.
UNASSIGNED: An elderly woman presented to the hospital with abdominal pain and fever. Her condition rapidly worsened with severe complications, such as multiple organ failure and central nervous system damage. The presence of R. japonica was quickly detected by metagenomic next-generation sequencing. On the basis of combined clinical manifestations and laboratory results, critical JSF was diagnosed and treated with doxycycline. The patient showed good prognosis. Typical symptoms (eschar and rash) were not observed in the early stage, consequently increasing the difficulty of clinical diagnosis.
UNASSIGNED: The delay of treatment caused by non-specific symptoms is an important factor affecting the progression of JSF. As an emerging pathogen detection method, mNGS has been successfully applied for disease diagnosis and treatment, and can be an important complement for the diagnosis of this disease.

UNASSIGNED: Severe complications may cause a fatal or disabling outcome in patients with Rickettsia japonica infection but are poorly understood.
UNASSIGNED: We identified 11 patients with only Rickettsia japonica infection with metagenomics next generation sequencing (mNGS) during April to November 2021 at Yichang Central People\'s Hospital, China. Clinical data were obtained through review of medical records.
UNASSIGNED: Most patients realized that they had symptoms about one or two days after being bitten. Fever (91%), pulmonary effusion (91%), rash or erythema (100%), abnormal urine (100%), neutropenia (100%), lymphopenia (100%), and thrombocytopenia (100%) were the most common clinical signs. Six severely ill patients were admitted to the intensive care unit and five had mild symptoms. Systemic manifestations such as vomiting (83%), neurological manifestations (100%), and disseminated intravascular coagulation (100%) were more frequently observed in the severe cases, 33.3% of whom developed purpura fulminans requiring amputation or skin graft, and 16.6% died two days after admission. Some patients experienced sequelae.
UNASSIGNED: Our study found that patients with critical Rickettsia japonica infection complicating disseminated intravascular coagulation had high risk of poor outcome.

Two patients from Huanggang, China, were diagnosed with spotted fever group (SFG) rickettsiosis-caused by spotted fever group rickettsiae (SFGR)-in 2021. This study aimed to investigate the clinical symptoms, laboratory examinations, epidemiological factors, and therapeutic responses in patients with SFG rickettsiosis-an emerging disease in this region. The patients showed a variety of clinical signs and symptoms, such as acute febrile illness with severe headache, myalgia, asthenia, anorexia, eschar, lymphadenopathy, and rash on the trunk and extremities. They exhibited increased neutrophil ratio, mild thrombocytopenia, liver dysfunction, and increased C-reactive protein and procalcitonin levels. Following treatment with doxycycline, the patients recovered completely. This is the first report of Rickettsia japonica infection in Huanggang City, Hubei Province, China. SFGR infection is a tick-borne disease, which can be effectively treated with doxycycline; however, it has a mortality rate of approximately 10% with delays in treatment. The Huanggang area is also a high-risk area for tick-borne severe fever with thrombocytopenia syndrome (SFTS). Therefore, SFTS and SFG rickettsiosis should be carefully diagnosed in this area and clinicians should be alert with respect to the possibility of infections with both SFTS and SFG rickettsiosis.