First detection of Bandavirus dabieense in ticks collected from migratory birds in the Republic of Korea.

The causative agent of severe fever with thrombocytopenia syndrome (SFTS) is Bandavirus dabieense, an emerging tick-borne zoonotic pathogen. Migratory birds have often been suggested as potential carriers of ticks that can transmit Bandavirus dabieense; however, their role remains unclear. The Republic of Korea (ROK) holds an important position as a stopover on the East Asian-Australasian Flyway. The present study aimed to investigate the potential involvement of migratory birds in the transmission of the SFTS virus (SFTSV) in the ROK. A total of 4,497 ticks were collected across various regions, including Heuksando and Daecheongdo, in the ROK, from bird migration seasons in 2022 and 2023. Genetic analysis of the SFTSV was performed for 96 ticks collected from 20 different species of migratory birds. Polymerase chain reaction (PCR) fragments of SFTSV were detected in one Haemaphysalis concinna nymph collected from a Black-faced Bunting (Emberiza spodocephala) and one Ixodes turdus nymph collected from an Olive-backed Pipit (Anthus hodgsoni) on Daecheongdo and Heuksando, respectively, during their northward migration in two spring seasons. This finding suggests that migratory birds can be considered as possible carriers and long-distance dispersers of ticks and associated tick-borne diseases. This study highlights the importance of clarifying the role and impact of migratory birds in the rapid expansion of tick-borne diseases, facilitating enhanced preparedness and the development of mitigation measures against emerging SFTS across and beyond East Asia.

Ixodid ticks from wild and domestic animals in East and Central Asian flyways.

Tick-borne diseases have a significant impact on human and animal populations, posing an increasing threat to public health, particularly in the context of climate change. Along with the various natural hosts of ticks, birds play a notable role in transmitting ticks and tick-borne pathogens, indicating the importance of monitoring flyways and establishing a cooperative network for comprehensive surveillance and to collect diverse tick samples across various regions. This study aimed to develop an international network for surveillance of disease, collection of sufficient tick samples, and overall identification of the geographical distribution of host and ticks in Asian regions, especially in 11 countries on East Asian and Central Asian flyways. Ticks were collected from wild animals, domestic animals, and vegetation to identify the differences between Ixodid ticks and understand tick distribution. We collected a total 6,624 of ticks from 11 collaborating Asian countries, the Republic of Korea (ROK), Japan, Thailand, Philippines, Indonesia, Cambodia, Vietnam, Taiwan, Hong Kong, Mongolia and Pakistan. We identified 17 host animals and 47 species of both residential and migratory birds. Ticks from birds collected from four countries (ROK, Japan, Hong Kong and Mongolia) belonged to two genera, Haemaphysalis and Ixodes, including Haemaphysalis (H.) longicornis, H. flava, H. concinna, H. hystricis, H. formosensis, Ixodes (I.) nipponensis and I. persulcatus. The potential of migratory birds to cross ecological barriers with ticks and tick-borne diseases indicated the need for further investigations to understand the migration of birds as potential vectors and the new influx of zoonotic diseases along migratory bird flyways. This study suggests the potential risk of spreading tick-borne diseases through birds, thus highlighting the importance of international cooperative networking.

Effectiveness of Morphological Sex Determination in the East Asian Barn Swallow (Hirundo rustica gutturalis) on Spring Migration.

Hyun-Young Nam, Seung-Yeon Lee, Sook-Young Cho, Chang-Yong Choi, Se-Young Park, Gi-Chang Bing, Chang-uk Park, Seul-Gi Seo, and Yang-Mo Kim (2018) Information on sexual dimorphism helps explain a species' evolution in sexual selection and conservation issues such as sex-specific response in environmental changes. The Barn Swallow (Hirundo rustica) is a well-known sexually dimorphic species in which males have longer tail streamers than females. However, when compared with the European-African or American subspecies, little information is available on morphological sex determination in the East Asian subspecies H. r. gutturalis, especially outside the breeding season, when opportunities for molecular sexing are often limited and morphological clues may be the only ones available for sex determination. We collected morphological data on H. r. gutturalis during the northbound spring migration at a stopover site off the Korean coast. Two of eight measured variables - streamer length (the difference in length between the 5th and 6th rectrices; T6-T5) and length of the white patch on the outermost tail (6th rectrix; T6) - were selected as the best predictors for sex determination by stepwise discriminant analysis. Quadratic discriminant functions based on these variables showed that 92.4-93.5% of females and 82.9% of males were correctly classified. Our results provide baseline information that will benefit more accurate sex determination of the East Asian Barn Swallows, especially during the early months of a calendar year in non-breeding and stopover areas.

Reduction of carcinogenic 4(5)-methylimidazole in a caramel model system: influence of food additives.

The effect of various food additives on the formation of carcinogenic 4(5)-methylimidazole (4-MI) in a caramel model system was investigated. The relationship between the levels of 4-MI and various pyrazines was studied. When glucose and ammonium hydroxide were heated, the amount of 4-MI was 556 ± 1.3 µg/mL, which increased to 583 ± 2.6 µg/mL by the addition of 0.1 M of sodium sulfite. When various food additives, such as 0.1 M of iron sulfate, magnesium sulfate, zinc sulfate, tryptophan, and cysteine were added, the amount of 4-MI was reduced to 110 ± 0.7, 483 ± 2.0, 460 ± 2.0, 409 ± 4.4, and 397 ± 1.7 µg/mL, respectively. The greatest reduction, 80%, occurred with the addition of iron sulfate. Among the 12 pyrazines, 2-ethyl-6-methylpyrazine with 4-MI showed the highest correlation (r = -0.8239).