It is sometimes known as "Chinese QX" as it was originally isolated following outbreaks of disease in the Qingdao region in China in the mid 1990s.
ບາງຄັ້ງມັນຖືກເອີ້ນວ່າ "QX ຂອງຈີນ" ຍ້ອນວ່າມັນຖືກແຍກອອກຈາກເດີມຫຼັງຈາກການລະບາດຂອງພະຍາດໃນເຂດ Qingdao ຂອງຈີນໃນກາງຊຸມປີ 1990.