Infection characteristics of Diplostomum spp. metacercariae (DsMc) were analyzed in fishes from 9 major water systems of Korea. A total of 15,879 fishes in 79 species were examined by the artificial digestion method for 8 years (2013–2020). DsMc were detected in 48 (60.8%) out of 79 fish species examined. The prevalence was higher in Pseudogobio esocinus (61.5%), Squalidus chankaensis (56.9%) and Zacco platypus (44.8%). The infection intensities were 22.1, 9.4, 7.5 and 6.7 per fish infected in Hemibarbus longirostris, P. esocinus, Z. platypus, and S. chankaensis respectively. The higher prevalence was shown in fishes from Yeongsan-gang (59.3%) and the middle reaches of Seomjin-gang (48.0%), and the higher infection intensities were revealed in fishes from above 2 regions and streams in east coast (83.1, 7.5, and 11.3 per fish infected). In index fish, Z. platypus, overall prevalence was 44.8% and the higher prevalence were revealed in the middle reaches of Seomjin-gang (79.6%), Geum-gang (79.2%) and Tamjin-gang (64.7%). The susceptibility index in index fish was highest in fish from the streams in east coast (13.64), and followed by fish from the middle reaches of Seomjin-gang (7.56) and Mangyeong-gang (4.75). This study provides several novel characteristics of DsMc infection in fishes with a report of 30 new second intermediate host of Diplostomum spp. in Korea.

Schistosomiasis remains a major neglected tropical disease, affecting approximately 600 million individuals worldwide and accounting for nearly 500,000 deaths annually. The principal causative species—Schistosoma haematobium, S. mansoni, and S. japonicum—drive significant morbidity through hepatomegaly, splenomegaly, and progressive hepatic fibrosis. Praziquantel (PZQ) remains the cornerstone of treatment; however, its limited efficacy against immature worms and eggs, combined with concerns over emerging drug resistance, underscores the urgent need for novel therapeutic alternatives. This study investigated the anti-schistosomal potential of green-synthesized zinc oxide (ZnO) nanoparticles (NPs) in a murine model of S. mansoni infection, benchmarked against PZQ. ZnO NPs were fabricated using ginger extract via an eco-friendly green synthesis approach. Fifty male BALB/c mice were randomly assigned to five groups (n=10): normal control, infected untreated control, infected treated with PZQ alone, infected treated with ZnO NPs alone, and infected treated with a PZQ–ZnO NP combination. Parasitological, histopathological, and fibrosis assessments were subsequently performed. All treatment groups demonstrated significant reductions in worm burden and tissue egg counts relative to infected untreated controls. Histopathological examination of untreated infected mice revealed extensive chronic granulomatous inflammation, concentric perioval fibrosis, fibroblast proliferation, hepatocellular necrosis, hydropic degeneration, marked collagen deposition, and portal-to-portal fibrous bridging. Treated groups, by contrast, exhibited marked hepatic improvement characterized by reduced granuloma size, diminished fibrosis, and decreased collagen deposition. Collectively, these findings indicate that green-synthesized ZnO NPs possess promising anti-schistosomal and antifibrotic properties, warranting further investigation as a potential adjunct or alternative therapeutic strategy for schistosomiasis management.

Psoriasis is a chronic inflammatory seronegative disease closely associated with ankylosing spondylitis and inflammatory bowel disease. This study aimed to investigate the anti-inflammatory effects of candidate metabolites, such as D-proline, L-iditol, and propionylcarnitine, identified in Clonorchis sinensis preparations, in in vitro and in vivo models. None of the 3 metabolites exhibited cytotoxicity within the tested concentration range. In LPS-stimulated RAW 264.7 cells, D-proline and L-iditol significantly reduced the expression of pro-inflammatory cytokines, and in an imiquimod-induced psoriasis-like mouse model, L-iditol significantly reduced disease severity and histopathological scores, whereas the effects of other metabolites were inconsistent. These research results suggest that L-iditol, a candidate metabolite identified in Clonorchis sinensis formulations, exhibits anti-inflammatory effects in both in vitro and in vivo environments and may have therapeutic potential for inflammatory skin diseases such as psoriasis.

Profilins are ubiquitous pan-allergens responsible for cross-reactivity between pollens and plant foods. While we previously demonstrated that recombinant Acanthamoeba profilin (rAc-PF) drives allergic airway inflammation via Th2/Th17 pathways in murine models, its clinical relevance in human allergic disease remains unclear. This study investigated rAc-PF as a novel inhalant allergen and its immunological impact on patients with allergic airway diseases. A total of 176 patients with allergic airway diseases underwent skin prick tests with rAc-PF and a standard panel of 55 common aeroallergens. Acanthamoeba-specific and rAc-PF–specific serum IgE levels were quantified using ELISA. To elucidate immune mechanisms, peripheral blood mononuclear cells from atopic asthma patients were stimulated with rAc-PF, and Th2/Th17 cytokine production was analyzed. Thirteen patients (7.4%) showed positive skin prick tests reactions to rAc-PF. This sensitization was significantly associated with tree, grass, and weed pollens, indicating a pan-allergen characteristic due to high cross-reactivity. Notably, one patient sensitized to rAc-PF reacted to no other common inhalants, suggesting rAc-PF as a unique causative agent. Patients exhibited significantly elevated levels of serum Acanthamoeba-specific and rAc-PF–specific IgE compared to healthy controls. Furthermore, rAc-PF stimulation of peripheral blood mononuclear cells from asthmatic patients induced robust production of IL-4, IL-5, IL-13, and IL-17A in humans. rAc-PF is identified as a novel allergen capable of inducing IgE-mediated sensitization and mixed Th2/Th17 responses. The strong association with pollen sensitization supports its role as an environmental pan-allergen. Therefore, rAc-PF should be considered a clinically relevant diagnostic target, especially in patients with polysensitization or unidentified triggers.

Malaria transmission remains high in rural Tanzania despite widespread use of insecticide-treated nets and indoor residual spraying. Outdoor biting and flexible host-feeding behavior of Anopheles mosquitoes reduce the effectiveness of these interventions. Livestock near households may influence vector behavior, but evidence from high-transmission rural settings is limited. A cross-sectional study was conducted from November 2022 to February 2023 in 5 villages of Misungwi District, involving 44 households (22 livestock-keeping and 22 non-livestock-keeping). Adult Anopheles mosquitoes were collected indoors and outdoors using Center for Disease Control light traps, identified morphologically and by PCR, and blood-meal sources were determined by ELISA. Host-feeding patterns were assessed using the human blood index, bovine blood index, and foraging ratios. A total of 611 female mosquitoes were collected, dominated by An. gambiae s.l. (96.1%) and An. funestus s.l. (3.9%). Livestock households had more mosquitoes (61.5%) and higher outdoor activity (67.3%), while non-livestock households had higher indoor collections (73.6%). Among 231 blood-fed mosquitoes, 150 (64.9%) were from livestock households and 81 (35.1%) from non-livestock households. In livestock households, 108 (72.0%) had animal blood only, 27 (18.0%) mixed blood, and 15 (10.0%) human blood only. In non-livestock households, 44 (54.3%) had human blood only, 24 (29.6%) mixed blood, and 13 (16.0%) animal blood only. An. arabiensis was opportunistic, while An. gambiae s.s. and An. funestus s.s. remained strongly anthropophilic. Livestock shifts feeding toward animals and increases outdoor activity but does not eliminate human feeding, highlighting the need for integrated malaria control strategies.

Ticks are important vectors of numerous zoonotic pathogens, yet integrated molecular surveillance of wildlife hosts and their parasitizing ticks remains limited in Korea. In this study, we investigated the occurrence of major tick-borne bacterial pathogens in wildlife and their associated ticks. Blood samples were collected from Korean water deer (Hydropotes inermis), raccoon dogs (Nyctereutes procyonoides), and wild boars (Sus scrofa), and a total of 246 ticks were obtained from these 34 animals. Molecular analyses identified multiple bacterial pathogens, including Anaplasma phagocytophilum, Ehrlichia canis, Bartonella schoenbuchensis, Rickettsia raoultii, Rickettsia monacensis, and Candidatus Rickettsia longicornii. Notably, E. canis was detected for the first time in blood samples from raccoon dogs and wild boars in Korea, and B. schoenbuchensis was identified in ticks for the first time in the country. In addition, R. monacensis exhibited a remarkably high minimum infection rate in Ixodes nipponensis, and all positive ticks were collected from raccoon dogs. Strikingly, Ca. R. longicornii was detected at a very high prevalence (94.1%) in wildlife blood samples, suggesting extensive circulation among wildlife hosts in the study area. These findings indicate that wildlife and their parasitic ticks may serve as important reservoirs of diverse tick-borne bacteria in Korea and highlight the importance of continuous molecular surveillance within a One Health framework.

The purpose of this study was to ascertain the status and patterns of pinworm Enterobius vermicularis infection among preschool children in Jeollanam-do from 2023 to 2025. Further, it aimed to assess changes in infection rates during the implementation of the test-and-treatment strategy. Cellophane tape swabs were collected from 12,608 children aged 0–6 years enrolled in daycare or kindergarten facilities in 8 cities and counties of Jeollanam-do. The samples were examined under a light microscope to diagnose pinworm infection. The overall infection rate over the 3-year period was 0.22% (28/12,608). The annual infection rate declined continuously from 0.35% in 2023 to 0.06% in 2025 (trend P<0.05). The infection rate did not vary significantly with sex (P>0.05), but was significantly higher in the 4–6 year age group (P<0.05), and was highest in Jangheung-gun (0.65%) and Goheung-gun (0.37%). The overall infection rate in this study was substantially lower than previously reported. However, this may represent a transient phenomenon reflecting environmental or behavioral factors associated with this specific period. Therefore, continuous monitoring is necessary.

The present study investigated the infection status of digenetic trematode metacercariae (DTM) in freshwater fish from Banbyeon-cheon in Yeongyang-gun, Gyeongsangbuk-do, Korea. A total of 211 freshwater fish representing 11 species were examined using the artificial digestion method in October 2023. Six taxa of DTM, including Clonorchis sinensis, Metagonimus spp., Centrocestus armatus, echinostomes, Exorchis oviformis, and Metacercaria hasegawai, were detected. The overall prevalence of DTM was 92.4% among the fish examined. The prevalence of C. armatus was the highest (52.8%), followed by E. oviformis (51.6%), M. hasegawai (35.6%), echinostomes (31.0%), C. sinensis (16.1%), and Metagonimus spp. (6.9%) in positive fish species. The infection intensity of C. armatus was 126 metacercariae per infected fish, whereas those of C. sinensis and Metagonimus spp. were 20 and 5.8 per infected fish, respectively. These findings indicate that at least 6 taxa of DTM, including C. sinensis and Metagonimus spp., are prevalent to varying degrees in fish from Banbyeon-cheon in Yeongyang-gun, Gyeongsangbuk-do, Korea. However, the potential risk of fishborne zoonotic trematodes, particularly C. sinensis, appears to be markedly lower than that reported in previous studies.

The first Korean case of Echinococcus multilocularis interpreted the probable origin of the isolate on the basis of cox1 sequence similarity, originally reporting 99.8%–99.9% similarity to Asian isolates and 99.5%–99.6% similarity to European isolates. To examine whether this similarity-based interpretation remains epidemiologically informative, we re-evaluated currently available cox1 sequences with high sequence identity at the accession level. Using AB780998.1 as the query, BLAST hits with ≥99.5% identity were collected, and 110 non-self accessions were manually annotated according to clade classifications reported in the source literature. Sequence alignment and phylogenetic assessment were performed with MAFFT and IQ-TREE. Across the re-evaluated dataset, sequences with identities from 99.5025% to 99.6269% were predominantly classified as European, whereas all sequences from 99.6891% to 100% were classified as Asian. The only 2 exceptions to this overall pattern were OR263180 and OR263183, which were classified as Asian despite falling within the lower identity band. These 2 accessions were reported in a study using a concatenated mitochondrial framework including cox1, cob, and nad2, suggesting that single-marker interpretation may be limited in such borderline cases. In the 1,608 bp alignment, 1,544 sites were constant and only 19 were parsimony-informative. Despite this limited variation, cox1 percent identity showed strong concordance with classification of Asian and European groups reported in the source literature. These findings indicate that high cox1 identity may serve as a practical proxy for broad lineage discrimination between Asian and European groups of E. multilocularis, although rare borderline cases may require confirmation with multiple mitochondrial markers.

Bartonella species are vector-borne pathogens that infect a wide range of hosts, including humans. Although several Bartonella species have been identified in rodents and arthropods in Korea, information on Bartonella detection in ticks removed from human patients remains limited. This study investigated the presence of Bartonella species DNA in human-biting ticks collected in Korea and screened for other tick-associated bacteria, including Coxiella endosymbiont. From January to December 2018, 35 ticks were removed from 29 tick-bitten patients in Jeollanam-do and Gwangju, Korea. Ticks were identified morphologically and molecularly by 16S rRNA gene PCR. The presence of Bartonella species was assessed using nested PCR targeting the 16S-23S internal transcribed spacer (ITS) region. The ticks were identified as Haemaphysalis longicornis (17/35, 48.6%), Amblyomma testudinarium (14/35, 40.0%), and Ixodes nipponensis (4/35, 11.4%). Two H. longicornis ticks tested positive for Bartonella species. Sequencing revealed 99.5% identity with B. bacilliformis isolate GJRITS124 in one tick and 98.9% identity with B. taylorii isolate 190731_HC2 in the other, both previously identified in Apodemus agrarius rodents in Korea. One B. bacilliformis-positive tick was also positive for Coxiella spp., and sequence analysis indicated a Coxiella endosymbiont showing 100.0% identity with the Coxiella-like endosymbiont strain 580. Phylogenetic analysis supported these findings; however, bacterial cultures from PCR-positive tick lysates were negative. This study provides baseline evidence of B. bacilliformis and B. taylorii, as well as Coxiella endosymbiont DNA in human-biting H. longicornis ticks in Korea and highlights the need for continued surveillance.

IgA vasculitis (IgAV) and Strongyloides stercoralis infection may both present with abdominal pain and purpura; however, glucocorticoid, the treatment for IgAV, is a major risk factor for S. stercoralis hyperinfection syndrome and disseminated strongyloidiasis. To date, only 2 cases of IgAV with concurrent S. stercoralis infection have been reported globally, both in children. We report a 72-year-old man presenting with abdominal pain and purpura. Diagnosed with IgAV during this admission, he received glucocorticoid therapy. However, the patient’s condition did not improve as expected. Subsequently, S. stercoralis was detected in the patient's sputum and stool. We report the first adult case of IgAV with concurrent S. stercoralis infection, highlighting the importance of screening patients with IgAV for strongyloidiasis before initiating immunosuppressive therapy.

In Vietnam, only few cases of cystic echinococcosis have been reported up to now. We report on the first case of cystic echinococcosis involving the central nervous system reported in Vietnam. Our patient, a 14-year-old child, presented with symptoms of headache and progressive tremor in the right hand that had lasted for 1 month and had worsened in the last days before admission. Following the demonstration of a large space occupying brain cyst by computed tomography, a presumptive diagnosis of a brain tumour was made, that was later overruled. Magnetic resonance imaging, a biopsy and serological analysis allowed for the diagnosis of a giant hydatid brain cyst. The patient underwent surgical removal of the cyst and was treated for 6 months post-surgery with albendazole. On follow-up, the clinical symptoms gradually improved, serology became negative and 1.5 years after the surgical intervention the patient was declared to be cured. This case highlights the importance of considering hydatid disease in differential diagnoses, even in regions where Echinococcus infections are considered rare.