Langya virus and SFTS virus coinfections in China mean a shared tick vector is likely

Key data from a recently published report about a novel virus identified in China indicate that the new virus, Langya henipavirus, or LayV, likely shares a tick vector with another virus. Table S5 in the 23-page supplement to an Aug. 3 New England Journal of Medicine paper, “A zoonotic henipavirus in febrile patients in China,” reports that of nine patients coinfected with the novel LayV and another virus, six also had the tick-borne severe fever with thrombocytopenia syndrome (SFTS) bunyavirus (patients # 27, 29, 30, 31, 33, 35).

Given that at least one tick species, Haemaphysalis longicornis, has been linked to transmission of this SFTS bunyavirus from animals to humans, then a leading hypothesis for the transmission of the novel LayV from animals to humans is this same tick species.

Epidemiologically both viruses:

• Have been reported in shrews in China (albeit different species so far);
• Were reported in Henan and Shandong provinces in eastern China and primarily found in farmers.

In addition, given that SFTS virus was found later in South Korea and Japan, and that some person-to-person transmission has been documented, then a search for this novel Langyavirus should occur in nations outside China. (In the USA, the tick species Haemaphysalis longicornis exists, but so far neither the SFTS virus nor the Langyavirus have been reported).

Also, given that the Mojiang henipavirus found in rats (not yet humans) in Yunnan province in southern China is the phylogenetically most closely related henipavirus to Langyavirus, then ticks should be tested in Yunnan and especially in the Mojiang cave area.

Key clinical findings in the initial 26 patients with Langyavirus infection alone include:

• The higher viral load in serum and throat swabs for the four pneumonia patients;
• Virus in the serum signifies a potential for blood-borne transmission.

Of note, a cluster of SFTS virus in nine patients in Shandong province reported in 2015 was linked to blood contact without personal protective equipment.