Identification of a new orthonairovirus associated with human febrile illness in China.

The genus Orthonairovirus, which is part of the family Nairoviridae, includes the important tick-transmitted pathogens Crimean-Congo hemorrhagic fever virus and Nairobi sheep disease virus, as well as many other poorly characterized viruses found in ticks, birds and mammals1,2. In this study, we identified a new orthonairovirus, Songling virus (SGLV), from patients who reported being bitten by ticks in Heilongjiang Province in northeastern China. SGLV shared similar genomic and morphological features with orthonairoviruses and phylogenetically formed a unique clade in Tamdy orthonairovirus of the Nairoviridae family. The isolated SGLV induced cytopathic effects in human hepatoma cells in vitro. SGLV infection was confirmed in 42 hospitalized patients analyzed between 2017 and 2018, with the main clinical manifestations being headache, fever, depression, fatigue and dizziness. More than two-thirds (69%) of patients generated virus-specific antibody responses in the acute phase. Taken together, these results suggest that this newly discovered orthonairovirus is associated with human febrile illness in China.

First detection of Borrelia miyamotoi infections in ticks and humans from the northeast of Inner Mongolia, China.

Borrelia miyamotoi is a relapsing fever spirochete that can cause chills, fatigue, headache, myalgia, arthralgia, and even meningitis, damaging human health. B. miyamotoi has a wide distribution since its discovery in Ixodes persulcatus in 1994. The human B. miyamotoi disease was first described in Russia in 2011. However, the epidemiological information in China is limited. Here, we report the molecular detection of B. miyamotoi in the northeast of Inner Mongolia, China. A total of 774 adult ticks and 771 blood samples of patients were collected, from April 2017 to August 2019 in the northeast of Inner Mongolia, and tested for B. miyamotoi using real time-PCR. Gene sequences of 16S rRNA, fla, and glpQ were obtained to reconstruct the phylogenetic relationship of B. miyamotoi from humans and ticks. The results showed the total prevalence of B. miyamotoi in ticks was 1.3% of 774 ticks, with rates of 2.6% in I. persulcatus, 0.78% in Dermacentor nuttalli, 1.3% in D. silvarum, and 0.4% in Haemaphysalis longicornis. Thirteen (1.7%) patients were confirmed as positive for B. miyamotoi. Patients were mainly 50-60-years old and had a history of tick contact. They presented flu-like symptoms, including fever, headache, poor spirit, dizziness, nausea, vomiting, hypodynamic, chest distress, and myalgia. Phylogenetic analysis showed that the B. miyamotoi in the present study belonged to the Siberian type, distinct from European and American types and the I. ovatus isolate from Japan. This is the first report of B. miyamotoi detection in both ticks and humans in the northeast of Inner Mongolia, China, indicating B. miyamotoi is present in the area. These findings suggest that people have a risk of infection with B. miyamotoi in this region, where it should be included the differential diagnosis of tick-borne diseases.

A New Segmented Virus Associated with Human Febrile Illness in China.

BACKGROUND: In 2017, surveillance for tickborne diseases in China led to the identification of a patient who presented to a hospital in Inner Mongolia with a febrile illness that had an unknown cause. The clinical manifestation of the illness was similar to that of tickborne encephalitis virus (TBEV) infection, but neither TBEV RNA nor antibodies against the virus were detected. METHODS: We obtained a blood specimen from the index patient and attempted to isolate and identify a causative pathogen, using genome sequence analysis and electron microscopy. We also initiated a heightened surveillance program in the same hospital to screen for other patients who presented with fever, headache, and a history of tick bites. We used reverse-transcriptase-polymerase-chain-reaction (RT-PCR) and cell-culture assays to detect the pathogen and immunofluorescence and neutralization assays to determine the levels of virus-specific antibodies in serum specimens from the patients. RESULTS: We found that the index patient was infected with a previously unknown segmented RNA virus, which we designated Alongshan virus (ALSV) and which belongs to the jingmenvirus group of the family Flaviviridae. ALSV infection was confirmed by RT-PCR assay in 86 patients from Inner Mongolia and Heilongjiang who presented with fever, headache, and a history of tick bites. Serologic assays showed that seroconversion had occurred in all 19 patients for whom specimens were available from the acute phase and the convalescent phase of the illness. CONCLUSIONS: A newly discovered segmented virus was found to be associated with a febrile illness in northeastern China. (Funded by the National Key Research and Development Program of China and the National Natural Science Foundation of China.).