Emerging Infectious Diseases - CDC Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link Centers for Disease Control and Prevention. CDC twenty four seven. Saving Lives, Protecting People A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Emerging Infectious Disease journal ISSN: 1080-6059 Expedited Articles Human Myiasis Resulting from Reemergence of Cochliomyia hominivorax Screwworm, Mexico, 2025–2026 O. Delgado-Cuellar et al. New World screwworm Articles from Emerging Infectious Diseases Current Issue Early Release CME Articles Article Search Volume 32, Number 8—August 2026 [PDF - 17.07 MB - 184 pages] Last Issue - Volume 32, Number 7—July 2026 Podcasts In This Issue Synopses Research Dispatches Research Letters Emerging Infection Networks Letter Letters Another Dimension Books and Media Etymologia Corrections About the Cover Synopses Medscape CME Activity Western Equine Encephalitis Virus in Blood Donors during Outbreak, Argentina, 2023–2024 [PDF - 1.15 MB - 8 pages] S. Blanco et al. View Abstract Cite This Article Western equine encephalitis virus (WEEV) reemerged in Argentina during 2023–2024, raising public health concerns and posing a potential threat to blood transfusion safety. We assessed the effect of WEEV circulation on the blood supply by implementing responsive, community-informed interventions within a regional hemovigilance system, including epidemiologic mapping, enhanced donor selection criteria, and alphavirus-specific nucleic acid testing. Among 637 donors residing in outbreak-affected areas, we detected 1 asymptomatic viremic donor. Phylogenetic analysis showed that the viral sequence clustered within the contemporary South American outbreak lineage, consistent with ongoing regional transmission. Those findings demonstrate silent WEEV circulation among blood donors and highlight the critical role of donor surveillance as a sentinel system for emerging arboviruses. Hemovigilance provides valuable insights into viral circulation in the broader population, underscoring the need to integrate molecular surveillance into routine blood bank practices to strengthen transfusion safety and public health preparedness. EID Blanco S, Frutos MC, Brenot K, Bustamante A, Carrizo LH, Gallego SV. Western Equine Encephalitis Virus in Blood Donors during Outbreak, Argentina, 2023–2024. Emerg Infect Dis. 2026;32(8):1213-1220. https://doi.org/10.3201/eid3208.260078 AMA Blanco S, Frutos MC, Brenot K, et al. Western Equine Encephalitis Virus in Blood Donors during Outbreak, Argentina, 2023–2024. Emerging Infectious Diseases. 2026;32(8):1213-1220. doi:10.3201/eid3208.260078. APA Blanco, S., Frutos, M. C., Brenot, K., Bustamante, A., Carrizo, L. H., & Gallego, S. V. (2026). Western Equine Encephalitis Virus in Blood Donors during Outbreak, Argentina, 2023–2024. Emerging Infectious Diseases, 32(8), 1213-1220. https://doi.org/10.3201/eid3208.260078. Research Use of Salmonella enterica Serovar Typhi Hemolysin E and Lipopolysaccharide IgA to Identify Enteric Fever Cases, South Asia [PDF - 2.59 MB - 10 pages] J. C. Seidman et al. View Abstract Cite This Article Existing methods to identify patients infected with Salmonella enterica serovar Typhi or Paratyphi are not adequately accurate, affordable, or efficient. We evaluated the performance of antibodies to Salmonella Typhi hemolysin E (HlyE) and lipopolysaccharide (LPS) in Bangladesh, Nepal, and Pakistan for enteric fever case identification. We measured plasma concentrations of HlyE and LPS IgA in blood culture–confirmed enteric fever case-patients and in febrile controls with laboratory-confirmed alternative etiologies. Combining LPS and HlyE IgA discriminated enteric fever cases from other febrile illnesses with an area under the receiver operating characteristic curve (AUC) of 0.93 (specificity 86% at a fixed 90% sensitivity). LPS IgA alone performed nearly as well (AUC 0.92). In children <5 years of age, the combined biomarkers outperformed either biomarker alone (AUC 0.96 vs. 0.94 for HlyE, 0.93 for LPS). Our findings support use of HlyE and LPS IgA–based assays for enteric fever diagnosis in endemic settings. EID Seidman JC, Aiemjoy K, Adnan M, Dehraj I, Iqbal J, Iqbal K, et al. Use of Salmonella enterica Serovar Typhi Hemolysin E and Lipopolysaccharide IgA to Identify Enteric Fever Cases, South Asia. Emerg Infect Dis. 2026;32(8):1221-1230. https://doi.org/10.3201/eid3208.250753 AMA Seidman JC, Aiemjoy K, Adnan M, et al. Use of Salmonella enterica Serovar Typhi Hemolysin E and Lipopolysaccharide IgA to Identify Enteric Fever Cases, South Asia. Emerging Infectious Diseases. 2026;32(8):1221-1230. doi:10.3201/eid3208.250753. APA Seidman, J. C., Aiemjoy, K., Adnan, M., Dehraj, I., Iqbal, J., Iqbal, K....Charles, R. C. (2026). Use of Salmonella enterica Serovar Typhi Hemolysin E and Lipopolysaccharide IgA to Identify Enteric Fever Cases, South Asia. Emerging Infectious Diseases, 32(8), 1221-1230. https://doi.org/10.3201/eid3208.250753. Qualitative Risk Assessment of Infectious Agents Associated with Canine Importation into Canada, 2023–2024 [PDF - 1.93 MB - 10 pages] V. Leung et al. View Abstract Cite This Article Dog importation into Canada has grown substantially since the early 2010s, and concerns have been raised regarding the potential introduction of infectious agents. We conducted a qualitative risk assessment of infectious agents associated with canine importation into Canada. We adapted international risk assessment methodologies coupled with an expert consultation. We estimated likelihood of entry, likelihood of canine exposure, and magnitude of impact of exposure to individual canines and the canine population for all hazards (n = 53). We also completed estimates for likelihood of human exposure and magnitude of impact of exposure on individual humans and the human population for zoonotic hazards (n = 33). Hazards were commonly ranked moderate or high for likelihood of entry and exposure estimates. Magnitude of impact of exposure estimates were assessed at much lower levels, indicating more restricted health impacts. Our study provides a foundation for future risk mitigation, including caregiver education, veterinary assessments, and importation regulations. EID Leung V, Chiasson J, Patterson V, Narasimhan A, Anderson M, Epp T, et al. Qualitative Risk Assessment of Infectious Agents Associated with Canine Importation into Canada, 2023–2024. Emerg Infect Dis. 2026;32(8):1231-1240. https://doi.org/10.3201/eid3208.251602 AMA Leung V, Chiasson J, Patterson V, et al. Qualitative Risk Assessment of Infectious Agents Associated with Canine Importation into Canada, 2023–2024. Emerging Infectious Diseases. 2026;32(8):1231-1240. doi:10.3201/eid3208.251602. APA Leung, V., Chiasson, J., Patterson, V., Narasimhan, A., Anderson, M., Epp, T....Clow, K. M. (2026). Qualitative Risk Assessment of Infectious Agents Associated with Canine Importation into Canada, 2023–2024. Emerging Infectious Diseases, 32(8), 1231-1240. https://doi.org/10.3201/eid3208.251602. Rapid Expansion of Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Genotype D1.1 Virus across Flyway Regions, North America, Fall 2024 [PDF - 1.49 MB - 10 pages] M. Scotch et al. View Abstract Cite This Article Highly pathogenic avian influenza clade 2.3.4.4b virus continues to circulate in North America and has caused severe human disease. That clade includes genotype D1.1, which became dominant in birds in late 2024. Recent phylodynamic reconstructions place D1.1 emergence in mid-2024 but differ on its inferred origin and early dissemination pathways. We combined targeted surveillance of wild birds in Arizona with publicly available US clade 2.3.4.4b hemagglutinin sequences to estimate when D1.1 genotype emerged and to infer its diffusion among the 4 major US flyways. Phylodynamic analyses showed transitions concentrated among adjacent flyways regions, consistent with stepwise dissemination during fall 2024 and limited support for long-distance Pacific–Atlantic exchange. The Pacific Flyway showed patterns consistent with an early source and the Central Flyway with a secondary hub linked to onward spread. Our findings support coordinated genomic surveillance across adjacent flyways to reduce detection delays and improve situational awareness during rapid viral expansion. EID Scotch M, Faleye T, Urquidez-Negrete A, Varsani A, Fan A, Justice-Allen A. Rapid Expansion of Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Genotype D1.1 Virus across Flyway Regions, North America, Fall 2024. Emerg Infect Dis. 2026;32(8):1241-1250. https://doi.org/10.3201/eid3208.260205 AMA Scotch M, Faleye T, Urquidez-Negrete A, et al. Rapid Expansion of Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Genotype D1.1 Virus across Flyway Regions, North America, Fall 2024. Emerging Infectious Diseases. 2026;32(8):1241-1250. doi:10.3201/eid3208.260205. APA Scotch, M., Faleye, T., Urquidez-Negrete, A., Varsani, A., Fan, A., & Justice-Allen, A. (2026). Rapid Expansion of Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Genotype D1.1 Virus across Flyway Regions, North America, Fall 2024. Emerging Infectious Diseases, 32(8), 1241-1250. https://doi.org/10.3201/eid3208.260205. Virulence of Burkholderia pseudomallei Strains from Western Hemisphere and Africa in Mice [PDF - 3.58 MB - 13 pages] C. P. Klimko et al. View Abstract Cite This Article Melioidosis, caused by Burkholderia pseudomallei, is an emerging disease in the United States and was declared endemic to the Gulf Coast region in 2022. Melioidosis has been sporadically reported in the American continents, the Caribbean, and more recently in Africa. We conducted lethal dose analyses in BALB/c and C57BL/6 mice exposed to small particle aerosols of B. pseudomallei strains from the Western Hemisphere and Africa. Those isolates exhibit a variety of virulence patterns, including rapidly-lethal disease and delayed onset of fatal disease. We found that the isolates we tested grew similarly in culture but displayed major differences in biofilm formation. Our data contribute to the growing knowledge of geographically distinct B. pseudomallei isolates and aid in ensuring that medical countermeasures in development are effective against a diverse collection of bacterial strains. EID Klimko CP, Meinig J, Mlynek KD, Rill NO, Biryukov SS, Dankmeyer JL, et al. Virulence of Burkholderia pseudomallei Strains from Western Hemisphere and Africa in Mice. Emerg Infect Dis. 2026;32(8):1251-1263. https://doi.org/10.3201/eid3208.260069 AMA Klimko CP, Meinig J, Mlynek KD, et al. Virulence of Burkholderia pseudomallei Strains from Western Hemisphere and Africa in Mice. Emerging Infectious Diseases. 2026;32(8):1251-1263. doi:10.3201/eid3208.260069. APA Klimko, C. P., Meinig, J., Mlynek, K. D., Rill, N. O., Biryukov, S. S., Dankmeyer, J. L....Cote, C. K. (2026). Virulence of Burkholderia pseudomallei Strains from Western Hemisphere and Africa in Mice. Emerging Infectious Diseases, 32(8), 1251-1263. https://doi.org/10.3201/eid3208.260069. Detection of Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Genotype D1.2 Virus in Swine after Experimental Inoculation [PDF - 3.95 MB - 11 pages] H. Seger et al. View Abstract Cite This Article Highly pathogenic avian influenza H5NX clade 2.3.4.4b viruses continue to circulate globally. Reintroduction of Eurasian lineage viruses into North America and reassortment with endemic low pathogenicity strains have resulted in new genotypes, including D1.2. To assess pathogenicity and cellular tropism, we intranasally inoculated genotype D1.2 virus into pigs. We isolated virus from nasal secretions from most inoculated animals for multiple days. At 5 days postinoculation, PCR and immunohistochemistry detected virus in musculoskeletal, respiratory, digestive, lymphatic, and nervou…