2019;8(1):869-878. doi: 10.1080/22221751.2019.1622997.

Detection and characterization of an emerging type of Babesia sp. similar to Babesia motasi for the first case of human babesiosis and ticks in Korea.


Babesiosis is a tick-transmitted intraerythrocytic zoonosis. In Korea, the first mortalities were reported in 2005 due to Babesia sp. detection in sheep; herein we report epidemiological and genetic characteristics of a second case of babesiosis. Microscopic analysis of patient blood revealed polymorphic merozoites. To detect Babesia spp., PCR was performed using Babesia specific primers for β-tubulin, 18S rDNA, COB, and COX3 gene fragments. 18S rDNA analysis for Babesia sp., showed 98% homology with ovine Babesia sp. and with Babesia infections in Korea in 2005. Moreover, phylogenetic analysis of 18S rDNA, COB, and COX3 revealed close associations with B. motasi. For identifying the infectious agent, Haemaphysalis longicornis (296) and Haemaphysalis flava (301) were collected around the previous residence of the babesiosis patient. Babesia genes were identified in three H. longicornis: one sample was identified as B. microti and two samples were 98% homologous to B. motasi.

Our study is the first direct confirmation of the infectious agent for human babesiosis. This case most likely resulted from tick bites from ticks near the patient house of the babesiosis patient. H. longicornis has been implicated as a vector of B. microti and other Babesia sp. infections.



Everyone’s been waiting with bated breath on what the Asian Long-horned tick is transmitting.  We know it’s transmitting numerous pathogens in Asia but has yet to be found to transmit pathogens here in the U.S., although the tick itself is spreading geographically like wildfire. This is the tick that clones itself and drains cattle of its blood.  This article shows the ticks and transmittable diseases in South Korea.

The full-length article tells the unfortunate story of an elderly men’s death 36 hours after hospitalization due to an emerging type of Babesia due to a tick bite. 

A blood sample was obtained from the jugular vein in the patient that presented with dizziness and general weakness. 

No microorganisms were isolated from the blood culture.

Microscopy revealed the following:

Upon light microscopic examination, variable intraerythrocytic parasites as ring forms, pear-shaped forms, paired pyriforms, pleomorphic ring forms, and multiple-infected parasites and clusters of extracellular rings were detected in Giemsa-stained blood smears. The percentage of parasitaemia was 1.8% (Figure 1). Maltese cross forms comprising four masses in an erythrocyte that are often described as a characteristic of B. microti infection were not detected in most blood smears (Figure 1).

Please note that the patient would have failed a simple blood test and even microscopy revealed atypical findings as well as the fact parasitemia was less than 2%.

Yet, 2% was enough to kill a man.

Tick collections were performed by dividing the area around the patient’s residence and the findings were:

A total of 597 ticks were collected around the patient’s residence, including 296 H. longicornis (186 adult, 41 nymphs, and 68 larvae) and 301 Haemaphysalis flava (1 adult and 300 larvae) (Table 2). Among these, 94% of the ticks were collected in both the front yard of patient’s residence (442 ticks) and associated hill III (124 ticks). Based on the results of the amplification of Babesia genes in each tick, 2 (0.3%) were positive for 18S rDNA of Babesia species, 1 (0.2%) for COB and COX3, and 1 (0.2%) for β-tubulin gene of B. microti. While the nymph of H. longicornis yielded a positive result for only 18S rDNA, one female tick of H. longicornis yielded positive results for 18S rDNA, COB, and COX3 gene fragments. Also, one female tick of H. longicornis only yielded positive results for β-tubulin gene of B. microti (Table 3).

Please note two things: the high amount of ticks found right in his yard and the low incidence of infected ticks – yet, it only took one to kill him.

The Discussion section reveals some interesting things:

Previously, seven different Babesia spp., B. microti, B. divergens, B. bovis, B. canis, B. duncani, B. venatorium, and a novel Babesia sp. similar to ovine babesias were reported to cause human babesiosis...Human babesiosis (KCDC-1) in 2017 was the second case identified in Korea and the sequence of Babesia sp. was very closely related to that of KO1 and Liaoning, China. These large Babesia are clearly distinct from other agents of human babesiosis based on their shape and phylogeny. These results suggest that the causative agent in their case of babesiosis is a novel large Babesia parasite infecting humans and may be highly fatal….

the identified Babesia parasites (in the patient) might be B. motasi, and this is the first study to detect B. motasi in human babesiosis and H. longicornis in Korea.


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