The Belén District in Loreto Region, Peru, is known for its extensive riverfront areas, where many houses are built on stilts and float during the rainy season. We conducted fecal examinations on 997 schoolchildren (ages 4–14 years; 488 boys, 497 girls) across 4 schools in Belén using the Kato-Katz thick smear and formalin-ethyl acetate sedimentation techniques. The results revealed high rates of soilborne helminths and waterborne protozoan infections, with an overall parasite-positive rate of 79.7%. The primary helminth species were Ascaris lumbricoides (39.2%), Trichuris trichiura (33.2%), Hymenolepis nana (3.4%), hookworms (2.1%), and Enterobius vermicularis (1.5%). The main pathogenic protozoans were Giardia lamblia (20.9%) and Entamoeba histolytica/E. dispar (14.2%), along with Cryptosporidium-like coccidian (4.6%). Non-pathogenic protozoans included Entamoeba coli (31.5%), Endolimax nana (15.1%), and Blastocystis hominis (3.7%). The intensity of soilborne helminth infections was very high for A. lumbricoides (average eggs per gram of feces per child: 18,589), followed by T. trichiura (1,501) and hookworms (160). The prevalence of anemia, often associated with malnutrition, was moderate at 33.1% (298 anemic children among 901 examined). Mass deworming was initiated with albendazole 400 mg, 3 times a year, in conjunction with health education and environmental sanitation. Metronidazole was administered once at a dose of 200 mg 3 times daily for 10 days. A notable finding in this study was that soilborne and waterborne parasites are both highly prevalent among schoolchildren in the floating villages of the Belén District, Loreto Region. Sustained mass deworming is urgently needed and the WASH program is crucial.

Until now, 3 Metagonimus spp. (M. yokogawai, M. takahashii, and M. miyatai) causing human metagonimiasis have been reported in Korea. In this study, we investigated the possible presence of Metagonimus spp. other than these 3 species using human fecal samples from an endemic area in Korea. DNA was extracted from Metagonimus egg-positive fecal samples collected from residents of Gurye-gun, Jeollanam-do. A total of 21 representative mitochondrial cytochrome c oxidase subunit I sequences were obtained by PCR and cloning, and sequencing. Phylogenetic analysis revealed 1 cluster corresponding to M. yokogawai (n=10) and 2 additional distinct clusters corresponding to M. kogai (n=8) and M. saitoi (n=3), which were proposed as new species in Japan in 2022. Pairwise cytochrome c oxidase subunit I distances were low for M. yokogawai and M. kogai (mean Kimura 2-parameter: 0.005–0.006), whereas M. saitoi showed higher Korea–Japan values (~0.029), a pattern consistent with geographic structuring. In conclusion, we provide the first molecular evidence for the occurrence of M. kogai and M. saitoi in human fecal samples in Korea. Further confirmation using adult morphology, additional nuclear markers, and ecological surveys are needed to clarify metagonimiasis transmission in the Seomjin-gang (river) basin.

Perkinsus marinus is a significant pathogen in oyster aquaculture with expanding host and geographic ranges. This study evaluated the prevalence and infection intensity of P. marinus in major oyster farming regions across the USA, Mexico, Brazil, and Korea using a quantitative PCR (P. marinus–specific TaqMan quantitative PCR assay, Pm-qPCR) assay. Eastern oysters (Crassostrea virginica) were sampled from 7 USA sites, while Pacific oysters (Magallana gigas) were collected from Mexico, Brazil, and Korea. Compared to conventional PCR, the Pm-qPCR assay demonstrated significantly higher sensitivity, detecting P. marinus in >80.0% of samples at most sites and up to 100.0% in Port Norris, USA. Lower prevalence was found in Wellfleet, USA (58.0%) and Korean sites (63.0%–70.0%). The lowest infection intensities (<1,000 copies) were recorded at a high-energy open-water site in Buan, Korea. The assay’s specificity was confirmed using negative control oysters from Canada. These findings provide critical baseline data on P. marinus distribution and emphasize the superior diagnostic value of Pm-qPCR for early detection. As P. marinus spreads globally, sensitive and standardized tools like this assay are essential for disease surveillance and aquaculture biosecurity.

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.

Phlebotomine sandflies, important vectors of leishmaniasis, were surveyed between 2020 and 2023 in 4 southern regions of Uzbekistan—Surkhandarya, Kashkadarya, Jizzakh, and Samarkand—where human cases have been reported. A total of 2,905 specimens were collected and identified, representing 9 species from 2 genera: Phlebotomus (P. papatasi, P. sergenti, P. longiductus, P. caucasicus, P. mongolensis, P. andrejevi, P. alexandri) and Sergentomyia (S. sogdiana, S. grecovi). Sandfly abundance was highest in Kashkadarya (43.0%, n=1,249), followed by Surkhandarya (33.7%, n=979), Jizzakh (12.7%, n=369), and Samarkand (10.6%, n=308). P. sergenti was the most frequently detected species, predominating in Jizzakh (68.8%), Samarkand (63.3%), and Surkhandarya (42.1%), while P. papatasi was also prevalent, particularly in Kashkadarya (26.4%) and Surkhandarya (38.6%). In contrast, P. longiductus, P. alexandri, and S. grecovi were detected at relatively low frequencies.. These findings provide critical baseline data on sandfly species composition and regional distribution, which are essential for developing effective surveillance and control strategies to prevent cutaneous and visceral leishmaniasis in Uzbekistan.