Yuma Ohari

Yuma Ohari

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 April 2019 in Parasitology International
Verified
Journal Article
Closed access
Uday Kumar MohantaUday Kumar Mohanta
Uday Kumar Mohanta
TWTakuya Watanabe
Takuya Watanabe
ANAnisuzzaman
Anisuzzaman
YOYuma Ohari
Yuma Ohari
TITadashi Itagaki
Tadashi Itagaki

10 May 2021 in Pathogens
Verified
Journal Article
Open access
PDF file
Ehab MossaadEhab Mossaad
Ehab Mossaad
AGAlex S. Kiarie Gaithuma
Alex S. Kiarie Gaithuma
YMYassir O. Mohamed
Yassir O. Mohamed
SKSUGANUMA Keisuke
SUGANUMA Keisuke
Rika Umemiya-ShirafujiRika Umemiya-Shirafuji
Rika Umemiya-Shirafuji
Xuenan XuanXuenan Xuan
Xuenan Xuan
Ticks transmit many pathogens with public health and veterinary importance. Despite the wide distribution of tick-borne pathogens in Sudan, the information on the tick–pathogen relationship needs to be updated, particularly using modern molecular techniques. This cross-sectional study, conducted between September and November 2019, used morphology, PCR, and sequencing to confirm the identity of adult cattle ticks (male and female; n = 536) from Khartoum State (n = 417) and East Darfur State (n = 119). Moreover, the presence of Theileria annulata, Babesia bigemina, B. bovis, Anaplasma marginale, and Ehrlichia ruminantium was detected and confirmed in each tick using species-specific PCR or nested PCR and sequencing. The most economically important tick genera, Rhipicephalus, Hyalomma, and Amblyomma, were prevalent in the study area, and 13 different tick species were identified. The most prevalent tick species were Rhipicephalusevertsi evertsi (34.3%) and Hyalomma anatolicum (57.3%) in Khartoum State, and Rhipicephalus annulatus (27%), Rhipicephalus decoloratus (25%), and Hyalomma rufipes (29%) in East Darfur State. We detected all five pathogens in both states. To the best of our knowledge, this is the first study to report the presence of E. ruminantium, its vector Amblyomma variegatum, and B. bovis in Khartoum State. Further, this is the first report on most tick and pathogen species identified in East Darfur State. Our findings indicate the migration of some tick and pathogen species beyond their distribution areas in the country, and this consideration is necessary to develop future control strategies.


29 November 2024 in Ticks and Tick-borne Diseases
Verified
Journal Article
Open access
MIMebuki Ito
Mebuki Ito
MMMiku Minamikawa
Miku Minamikawa
AKAnastasiia Kovba
Anastasiia Kovba
HNHideka Numata
Hideka Numata
TITetsuji Itoh
Tetsuji Itoh
MSMariko Sashika
Mariko Sashika
Yezo virus (YEZV) is an emerging tick-borne virus that causes acute febrile illness. It has been continuously reported in patients and ticks in Japan and China since its first identification in Hokkaido, Japan. While serological tests have demonstrated that YEZV infections are prevalent in wild animals, such as raccoons (Procyon lotor), the determinants of infection in wild animals remain largely unknown. We examined the prevalence of YEZV in invasive raccoons, native tanukis (raccoon dogs, Nyctereutes procyonoides albus), and ticks in six study areas in Hokkaido between 2018 and 2023 to identify ecological factors underlying YEZV infection in wild animals. YEZV RNA fragments were detected in 0.22% of the 1,857 questing ticks. Anti-YEZV antibodies were detected in 32 of the 514 (6.2%) raccoon serum samples and in 5 of the 40 (12.5%) tanuki serum samples. Notably, the seroprevalence in raccoons varied significantly in one of the study areas over the years, that is, 0.0%, 60.0%, and 28.6% in 2021, 2022, and 2023, respectively, implying the temporary emergence of YEZV microfoci. By analyzing the tick load and YEZV seropositivity in raccoons in a field-based setting, we found a positive correlation between adult Ixodes ovatus load and YEZV-antibody positivity, highlighting the importance of I. ovatus in YEZV infection in wild animals. We also explored the environmental and host factors influencing YEZV seropositivity in raccoons and tanukis and found that landscape factors, such as the size of forest area around the trap site, were crucial for YEZV seropositivity in these animals. The significant variables for YEZV seropositivity in raccoons were partially different from those affecting tick infestation intensity in raccoons. The present results extend our understanding of tick-borne virus circulation in the field, emphasizing the unique ecology of the emerging YEZV.

1 October 2017 in Parasitology International
Verified
Journal Article
Closed access
MIMadoka Ichikawa-Seki
Madoka Ichikawa-Seki
TSTomoko Shiroma
Tomoko Shiroma
TKTatsuya Kariya
Tatsuya Kariya
RNRyo Nakao
Ryo Nakao
YOYuma Ohari
Yuma Ohari
SFShinya Fukumoto
Shinya Fukumoto

22 July 2017 in Parasitology Research
Verified
Journal Article
Closed access
PDF file
KHKei Hayashi
Kei Hayashi
WTWenQiang Tang
WenQiang Tang
YOYuma Ohari
Yuma Ohari
MOMaiko Ohtori
Maiko Ohtori
Uday Kumar MohantaUday Kumar Mohanta
Uday Kumar Mohanta
TITadashi Itagaki
Tadashi Itagaki