Early Release

Synopses

• Outbreak of Legionnaires’ Disease Linked to Newly Installed Residential Water Heaters, the Netherlands, 2022–2023
  D. Reukers et al. View Abstract

  During 2022–2023, two small Legionnaires’ disease (LD) clusters (2 and 4 cases) occurred in 2 residential apartment buildings in the Netherlands. All case-patients recently installed a new brand A water heater. Environmental sampling revealed Legionella pneumophila serogroup 1 sequence type 37 in the hot water system of each case-patient’s apartment, matching 1 clinical isolate. We conducted a case–control study to evaluate whether brand A water heaters were linked to cases in the 2 clusters. We identified 23 LD case-patients, 21 of whom had a brand A water heater installed <6 months before illness onset. Four cases had a genotypic match between clinical and environmental isolates; none of 31 control-patients had recently installed a water heater. Analyses showed that LD cases were strongly associated with new brand A water heaters (OR 542 [95% CI 24.76–11,854.03]); the manufacturer implemented control measures. Residential water heaters could serve as L. pneumophila transmission sources.

• Emerging Risk for Human T-Cell Leukemia Virus Type 1 Transmission with HIV-Positive Breastfeeding Support
  A. Meybeck et al. View Abstract

  Human T-cell leukemia virus 1 (HTLV-1) is a neglected retrovirus affecting 5–10 million persons worldwide. Most infections are asymptomatic, but HTLV-1 can cause adult T-cell leukemia or lymphoma and HTLV-1–associated myelopathy. Although mother-to-child transmission through breastfeeding is preventable, few countries have policies that include antenatal screening. The World Health Organization recommends integrating HTLV-1 into HIV and sexually transmitted infection strategies. HIV guidelines in high-income countries increasingly support breastfeeding under controlled conditions, creating increased risk for unrecognized HTLV-1 transmission. We reviewed existing policies for HTLV-1 mother-to-child transmission and considered integration of HTLV prevention into HIV response. We discovered inconsistent guidance across HIV, pediatric, and obstetric fields leading to conflicting counseling of expectant mothers. Integration of HTLV-1 prevention into HIV guidelines and harmonization with maternal and child health policies is essential for awareness among providers. Prevention through screening and avoiding breastfeeding remains the cornerstone of HTLV-1 control.

• Epidemiology and Clinical Features of Balamuthia mandrillaris Infection, China
  T. Yang et al. View Abstract

  Balamuthia mandrillaris is a highly lethal free-living ameba that primarily affects the skin and central nervous system, manifesting clinically as chronic granulomatous lesions and granulomatous encephalitis. Once the central nervous system is involved, the mortality rate exceeds 90%. No standardized treatment regimen has yet been established. In this review, we summarized 66 cases reported from China. The median patient age was 36 years (range 10 months–77 years); 62.12% patients were male and 37.88% female. Fifty-five (83.33%) patients were immunocompetent. For 42 (63.64%) patients, initial symptoms were cutaneous manifestations; of those, central nervous system involvement subsequently developed in 25 (59.52%) patients. Twenty-four (36.36%) patients were hospitalized initially with encephalitis. Among the 63 patients with a known outcome, 43 (68.25%) succumbed to infection. For patients with cutaneous-only disease, the survival rate was 93.75%, whereas once the central nervous system was affected, mortality reached 96.00%.

• Medscape CME Activity
  Trichinellosis Outbreak Linked to Undercooked Bear Jerky, North Carolina, USA, 2024
  C. D. Gowler et al. View Abstract

  Trichinella spp. nematodes are parasites that can cause trichinellosis in humans after consumption of infected, undercooked meat. A November 2024 trichinellosis outbreak in western North Carolina, USA, resulted in 3 cases (2 probable, 1 confirmed), all linked to undercooked bear jerky. In total, 6 persons consumed the implicated meat (attack rate 50%). Molecular testing identified Trichinella spiralis in leftover meat from the same bear. This outbreak provides evidence of changing trichinellosis patterns. Low-cost safety measures and prevention efforts regarding safe wild game preparation are needed to avoid future outbreaks.

• Neurosurgical Biopsy and Resection for Diagnosis and Treatment of Balamuthia mandrillaris Amebic Encephalitis, United States
  B. Rubbab et al. View Abstract

  We report a systematic case review of antemortem neurosurgical resections and biopsies and outcomes including new lesions after procedure and survival in Balamuthia mandrillaris granulomatous amebic encephalitis. The investigation was prompted by a 5-year-old patient in the southwestern United States who was treated with nitroxoline, the 2021 Centers for Disease Control and Prevention regimen, and underwent 2 resections; initial resection site recurrence and a new lesion after resection prompted the question whether complete resection versus biopsy is associated with better outcomes. We conducted a literature review and found no substantial difference between neurosurgical resection versus biopsy-only groups. Limitations include case review, number of cases, and incomplete data available. Additional analyses comparing neurosurgical outcomes with outcomes of those diagnosed via blood or cerebrospinal fluid and metagenomic next-generation sequencing might provide more definitive answers. This case and systematic review provide evidence that treatment with nitroxoline and neurosurgical resection could contribute to survival in Balamuthia encephalitis case-patients.

Research

• Clinical Predictors of Fatal Outcomes from Human Leptospirosis, Thailand, 2015–2024
  U. Limothai et al. View Abstract

  Early predictors of fatal leptospirosis and the role of pathogen lineages remain poorly defined, limiting clinical risk stratification, genomic surveillance, and public health response in leptospirosis-endemic settings. We conducted a multicenter prospective cohort study of hospitalized patients with suspected leptospirosis in Thailand during 2015–2024. Among 459 patients with laboratory-confirmed cases, 25 (5.4%) died during hospitalization. Older age, higher total bilirubin, and higher leptospiremia were independently associated with in-hospital death, and a combined model demonstrated good discriminatory performance. We performed targeted amplicon sequencing analysis directly on clinical samples and whole-genome sequencing on available isolates. Genomic analysis identified Leptospira interrogans as the predominant species; clonal group 272 sequence type 34 was the predominant lineage and the only lineage observed among patients with fatal cases with available genomic data. Our findings support integration of clinical predictors and pathogen load for early risk stratification and highlight the potential value of genomic surveillance in leptospirosis-endemic settings.

• Adeno-Associated Virus Type 2 and Human Adenovirus Species F Type 41 Co-infection Associated with Acute Severe Hepatitis in Children, California, USA
  R. Zhuo et al. View Abstract

  Since late 2021, clusters of acute severe hepatitis of unknown etiology in previously healthy children, including some requiring liver transplantation, have been reported worldwide. Co-infection with adeno-associated virus type 2 (AAV2) and human adenovirus species F type 41 (HAdV-F41) has been identified in most cases. Global incidence peaked in 2022, and pediatric liver failure involving co-infection with AAV2 and HAdV-F41 has remained rare in recent years. We report 2 cases of pediatric liver failure associated with AAV2 and HAdV-F41 in California, USA, in March 2024 and January 2025. The patients had high adenovirus loads (393,000 and 480,000 copies/mL), extended adenovirus viremia (2 and 3.5 months), and high AAV2 viral loads (1.3 and 1.0 × 10⁶ copies/mL). One patient required liver transplantation; both patients recovered. Our findings underscore the need for heightened physician awareness and expanded surveillance to identify and characterize new cases, improve understanding of underlying pathophysiology, clarify risk factors, and inform therapeutic strategies.

• Molecular Epidemiology of Skin-Dwelling Filariae and Risk Factors for Mansonella streptocerca Infection, Gabon
  C. Sicard et al. View Abstract

  Mansonella streptocerca is a species of neglected skin-dwelling filarial nematode parasite with scarce epidemiologic data from Central Africa. We conducted a cross-sectional survey of 1,007 adults from 51 rural and semiurban communities in Gabon to update prevalence estimates and identify risk factors. Molecular analyses by quantitative PCR detected filarial DNA in 18.3% of skin snips; M. streptocerca predominated (14.2%), and Onchocerca volvulus (3.4%) occurred focally in a single rural area. Blood-dwelling parasite species such as Loa loa, M. perstans, and Mansonella sp. “DEUX” were rarely detected. M. streptocerca infection was 4 times more frequent in rural areas than in semiurban areas and independently associated with male sex, urticaria, and poor housing conditions. Wolbachia DNA occurred in 28% of M. streptocerca–positive samples, suggesting endosymbiosis. Our findings reveal a substantial but overlooked burden of M. streptocerca nematodes in Gabon and emphasize the need for integrated surveillance of skin-dwelling filarial infections in Central Africa.

• National Surveillance of Enterovirus D68 Upsurge, France, 2024
  M. Jeannoël et al. View Abstract

  In 2024, an early and rapid rise in enterovirus D68 (EV-D68) infections in France prompted the implementation of enhanced nationwide surveillance to characterize the outbreak. EV-D68 screening was performed as part of the routine hospital strategy of the 2 national reference laboratories and of the national surveillance of enterovirus infections. Of 919 patients, 49.1% (451/919) were adults. Severe infection was reported in 169 patients (102 children and 67 adults). We observed neurologic complications in 7 children (seizures and encephalitis) and 4 adults (myelitis). Infections peaked in week 38 and were associated with subgenotypes A2 and B3; A2 predominated, particularly in adults (317/457 [69.3%] A2 infections). Complete genome analyses identified a new A2-derived lineage with mutations clustering in exposed regions of viral capsid protein 1. Our findings highlight the substantial clinical impact of EV-D68 in adults as well as children, underscoring the need for broad clinical and genomic surveillance.

• Prognostic Value of PCR Cycle Threshold Value in Crimean-Congo Hemorrhagic Fever, Iraq, 2022–2023
  R. I. Khaleel et al. View Abstract

  Using laboratory and epidemiologic data collected in 2022 and 2023 in Iraq, we aimed to evaluate the diagnostic and prognostic performance of reverse transcription PCR (RT-PCR) in Crimean-Congo hemorrhagic fever (CCHF) patients and to identify factors associated with disease outcomes. CCHF was confirmed in 955 hospitalized patients. Among those, RT-PCR analysis showed that blood specimens from deceased patients had a lower median cycle threshold (Ct) value than did those who recovered; we used those data to determine a cutoff value. Univariate and multivariate logistic regression analysis indicated that low Ct values, hemorrhagic symptoms at admission, and age >15 years were independent determinants of fatal CCHF outcome. Viral load and patient age play key roles in the outcome of CCHF in Iraq. Ct value at admission, as a proxy for viral load, serves as a practical indicator to guide clinicians in managing CCHF patients.

• Predictive Approach to Mapping Angiostrongylus cantonensis Nematode Distribution, Canary Islands, Spain
  L. Anettová et al. View Abstract

  The invasive nematode Angiostrongylus cantonensis (rat lungworm) can cause eosinophilic meningitis in humans. Once restricted to Southeast Asia, A. cantonensis nematodes are now widespread across the tropics and has been reported in Europe. Tenerife, in the Canary Islands, and the Mediterranean region are emerging hotspots. We surveyed gastropods, rats, and lizards across Tenerife and detected the parasite in all host groups at 2.4%–41.6% prevalence. Using species distribution models, we identified precipitation seasonality as the main driver of habitat suitability; tree cover and climatic variability primarily shaped prevalence patterns. Modeling showed suitable habitats in northeastern Tenerife and several western Canary Islands but limited overlap with areas of dense human population. Multivariate environmental similarity surface analysis comparison with another A. cantonensis hotspot, Hawaii, USA, revealed similar environments across the archipelago, except for the novel northeastern Tenerife area. Although no human infections have been reported, continued vigilance is warranted because A. cantonensis nematodes are established in Tenerife.

• Investigation of donor-transmitted Strongyloides stercoralis infections in recipients of solid organ transplants, 2012–2024
  K. R. Gainor et al.

Historical Review

• Discovery of Cinchona as Antimalarial, Viceroyalty of Peru, Circa 1630
  J. Rojas-Jaimes et al. View Abstract

  The empirical discovery of the therapeutic power of Cinchona tree bark in the 17th Century has been one of the most important achievements in the history of medicine in its fight against malaria. Only after 2 centuries, since the isolation of its main alkaloid, quinine, could other important antimalarials, such as chloroquine, be synthesized, all of which helped to save hundreds of millions of lives. In this historical review, we examine the evidence, accessed from early documentary sources, concerning the discovery of Cinchona and its therapeutic value as an antimalarial during the Viceroyalty of Peru.

Dispatches

• Nipah Virus Shedding in Urine from Fruit Bats, Sri Lanka, 2018–2019
  C. Kohl et al. View Abstract

  Nipah virus causes outbreaks in humans with high case-fatality rates. In this study, we confirmed the presence of Nipah virus in Sri Lanka in Pteropus medius fruit bats, one of the known natural reservoir species. Sequences we generated were genetically related to Nipah virus strains from outbreaks in southern India.

• Phormia regina Fly as Vector for Ignatzschineria spp. Bacteremia in Persons Experiencing Homelessness, Canada, 2025
  E. Finlayson-Trick et al. View Abstract

  Ignatzschineria spp. bacteria are emerging pathogens whose vectors historically have not been clearly identified. We used molecular methods to establish a relationship between the black blow fly (Phormia regina) and human Ignatzschineria bacteremia in persons experiencing homelessness in Vancouver, British Columbia, Canada, validating a novel transmission pathway in a vulnerable urban population.

• Trends in Congenital Syphilis Cases by Maternal Country of Birth, Spain, 2016–2024
  V. Hernando et al. View Abstract

  The number of congenital syphilis cases in Spain remains low; 40 cases were confirmed during 2016–2024. However, a slight increase has been observed, particularly in children born to migrant mothers. Young maternal age, migrant status, and social disadvantages are warning signs that underscore the need to strengthen prenatal screening.

• Vascularized Iris Mass as Sentinel Manifestation of Syphilis in Patient with HIV Infection, Spain, 2025
  M. Caminal-Caramés et al. View Abstract

  Vascularized iris masses are rare, yet highly suggestive of syphilis. We report a 51-year-old man in Spain with HIV infection who had painful vision loss, rash, and an iris mass. Laboratory testing confirmed syphilis; ocular manifestations resolved with intravenous ceftriaxone and penicillin. Early recognition of syphilis can prevent vision loss and neurologic complications.

• Cluster of Human Tanapox Cases in Wildlife Reserve, South Africa, 2024
  M. Birkhead et al. View Abstract

  Tanapox is a rare, self-limiting, mosquitoborne viral zoonosis. During February–March 2024, we identified 11 human tanapox cases near Orpen in Kruger National Park, South Africa. We retrospectively identified 2 suspected cases from Pafuri from 2021, suggesting continued virus circulation. Public awareness of tanapox is essential for appropriate medical treatment.

• Cat-Scratch Disease Associated with Acute Hearing Loss, Israel
  M. Yakubovsky et al. View Abstract

  We report 5 patients in Israel with cat-scratch disease (CSD) who had unilateral sudden sensorineural hearing loss. Several mechanisms are plausible, but further research is needed to clarify pathogenesis. The cases highlight a previously underrecognized association between CSD and sudden sensorineural hearing loss, expanding the spectrum of cranial nerve neuropathies in CSD.

• Recurrent Facial Folliculitis Caused by Klebsiella aerogenes Sequence Type 117 in Men who Have Sex with Men
  G. Monsel et al. View Abstract

  We describe 17 cases of recurrent facial folliculitis caused by Klebsiella aerogenes bacteria in men who have sex with men in France, Belgium, and the United States. Whole-genome sequencing showed all isolates belonged to sequence type 117 or related lineages. Our findings suggest sexual transmission and highlight emerging clinical and public health concerns.

• Angiostrongylus cantonensis Rat Lungworm Detected in Rats, Madagascar, 2022–2023
  S. F. Randrianarisoa et al. View Abstract

  Angiostrongylus cantonensis, the rat lungworm, is a zoonotic parasite that causes eosinophilic meningitis in humans; the parasite is maintained in rat definitive hosts and transmitted through gastropod intermediate hosts. We report A. cantonensis prevalence and mitochondrial genome from oral swab specimens from rats in Madagascar, supporting swabs for noninvasive detection of this parasite.

• Household Transmission of Enterovirus D68, Washington and Oregon, United States, 2022–2024
  P. Roychoudhury et al. View Abstract

  During 2022–2024, a total of 35 of 1,040 households had a distinct symptomatic index case of enterovirus D68; estimated symptomatic secondary infection rate was 13.6%. Sequences from patients within households clustered closely; we observed 0–2 pairwise nucleotide differences between household cases 6–14 days apart.

Research Letters

• Detection of and Early Genomic Insights into Chikungunya Virus, Bolivia, 2025
  J. Chuquimia Valdez et al. View Abstract

  We report the detection and genomic characterization of chikungunya virus, an arbovirus, during a 2025 outbreak in Bolivia. We identified the circulating chikungunya virus lineage and the transmission dynamics by using genomic surveillance and phylogenetic analyses. Our findings highlight the utility of sustained genomic surveillance for monitoring emerging arboviruses.

• Emergence of West African Human T-Lymphotropic Virus 1aC Subgroup, Brazilian Amazon
  J. de Melo Silva et al. View Abstract

  In a cross-sectional survey of 1,397 residents of Manaus, Brazil, we found a seroprevalence of 0.3% for human T-lymphotropic viruses (HTLVs) 1/2 and identified HTLV type 1aC by phylogenetic analysis. Those findings provide evidence of introduction of West African HTLV-1aC into the Brazilian Amazon and highlight regional limitations in genomic surveillance.

• Chikungunya Outbreak, Cuba, July 2025
  M. M. Perez et al.
• Human pulmonary dirofilariasis in the context of pulmonary adenocarcinoma, 
North Queensland, Australia, 2023
  K. Murray et al.
• Ancylostoma ceylanicum Hookworm, Rural Papua New Guinea, 2020
  J. L. Scott et al. View Abstract

  We conducted a cross-sectional study of zoonotic hookworm Ancylostoma ceylanicum in humans in Western Province, Papua New Guinea, confirmed by internal transcribed spacer sequencing. Overall hookworm prevalence was 54.9%; A. ceylanicum hookworms were present in 3.3% of specimens. One Health approaches are needed for hookworm control in Papua New Guinea.

• Ophthalmomyiasis Outbreak Caused by Oestrus ovis Infection, Algeria, 2025
  Y. Zeng et al. View Abstract

  Ophthalmomyiasis is a rare eye infestation caused by fly larvae and more often seen in rural areas. We report an outbreak of 17 patients in Algeria with ophthalmomyiasis after sheep exposure. All patients fully recovered after removal of ocular Oestrus ovis larvae and topical therapy, highlighting the effectiveness of early detection and treatment.

• New World Ocular Dirofilariasis Caused by Dirofilaria repens Infection, United States
  B. J. Glasgow et al. View Abstract

  We describe an infection caused by Dirofilaria repens nematodes in California, USA. A firm nodule developed after an insect bite on a patient’s eyelid. Excision with morphologic and molecular analysis confirmed D. repens infection. Our findings confirm the necessity of both molecular and histological studies to identify nematode infections.

• Molecular Confirmation of Autochthonous Taenia saginata Infection, Timor-Leste, 2019
  H. Jin et al. View Abstract

  We report a case of autochthonous Taenia saginata infection in Timor-Leste. Screening of 1,121 schoolchildren revealed a 0.4% prevalence of human taeniasis. Genetic analysis of the mitochondrial cox1 gene identified group A lineage. Our findings fill a considerable geographic data gap and highlight the need for integrated One Health control strategies.

• Neurologic Alveolar Echinococcosis in Postpartum Zoo-Housed Gorilla, the Netherlands, 2024
  L. Derks et al. View Abstract

  We report a case of postpartum alveolar echinococcosis in a zoo-housed gorilla in the Netherlands in 2024, with cerebral involvement causing neurologic symptoms. Infection was likely acquired via contaminated feed. This case highlights diagnostic challenges, public health risks, and the need for preventive feed hygiene and surveillance in endemic regions.

• Dracunculus sp. PantanalBr Infection in Florida Panthers and Bobcat, Florida, USA
  M. J. Yabsley et al. View Abstract

  We used morphologic and genetic methods to analyze subcutaneous worms removed from endangered Florida panthers and a bobcat in Florida, USA, identifying Dracunculus sp. PantanalBr and several Dirofilaria spp. worms. Dracunculus sp. PantanalBr had been previously reported in a domestic dog and a jaguar in Brazil.

• Autochthonous Neurocysticercosis Brain Lesions Mimicking Metastatic Disease, Spain
  E. Hernández-Sánchez et al. View Abstract

  Autochthonous neurocysticercosis is exceptionally rare in Western Europe. We describe multiple brain lesions, initially mimicking metastases, during 2025 in a 60-year-old man in Spain without travel history. We confirmed diagnosis by neuroimaging and positive serology. Our study highlights cryptic local Taenia solium nematode transmission risks and diagnostic challenges in nonendemic regions.

Etymologia

• Fasciolopsis buski
  M. Calatri

Online Report

• Inconsistent Strategies to Mitigate the Effects of Batrachochytrium salamandrivorans, Europe
  P. Böning et al.

About the Cover

• Jimmy Carter and Eradication of Guinea Worm Disease
  S. O’Connor et al.

Synopsis

• Western Equine Encephalitis Virus in Blood Donors during Outbreak, Argentina, 2023–2024
  S. Blanco et al.

Research

• Evaluation of virulence of Burkholderia pseudomallei strains from the Western Hemisphere and Africa in the BALB/c and C57BL/6 mouse models of inhalational melioidosis
  C. P. Klimko et al.
• Use of Salmonella Typhi Hemolysin E and Lipopolysaccharide IgA to Identify Enteric Fever Cases, South Asia
  J. C. Seidman et al.
• Qualitative Risk Assessment of Infectious Agents Associated with Canine Importation into Canada, 2023–2024
  V. Leung 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
  M. Scotch et al.
• Systemic Distribution and Protracted Detection of Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Genotype D1.2 in Swine after Experimental Inoculation
  H. Seger et al.
• Association of Medically Attended Infections in Infancy with Long-Term Weight Gain and Obesity among Children, Southern California, USA
  Z. W. Taylor and J. C. Lin

Dispatches

• Camel Prion Disease, Tataouine, Tunisia, 2019–2021
  A. Amara et al.
• Integrated One Health Surveillance for Filovirus circulation in Border Communities of Cameroon Following the 2023 Equatorial Guinea Marburg Outbreak
  J. Ramassamy et al.
• Isolation of Infectious Highly Pathogenic Avian Influenza A (H5N1) Virus from Fetal Bovine Serum, United States, 2025
  A. R. Rebelo et al.
• Entomological Surveillance and Pathogen Detection focusing on Aedes (Stegomyia) aegypti and Dengue virus in an Arid Urban Environment
  N. Nowotny et al.
• Detection of Congenital Syphilis via Digital PCR and Next-Generation Sequencing, Colombia
  A. M. Bossa-Castro et al.

Research Letters

• Multifarm Outbreak of Novel Parvovirus in Pigs Associated with Exophthalmos and Erythema, the Netherlands, 2024
  T. J. Tobias et al.
• Hepatitis A Outbreak in a Skilled Nursing Facility — Los Angeles County, 2025
  M. T. Yazdi et al.
• Antibodies Cross-Reactive with Bundibugyo Virus in Ferrets Vaccinated with Ebola Virus Vaccine
  J. Wight et al. View Abstract

  Banked serum samples from ferrets previously immunized with the Ebola virus vaccine revealed a prominent but limited humoral immune response that cross-reacted with Bundibugyo virus. The supporting immunogenicity data we report may help guide the ongoing response to the current outbreak of Bundibugyo virus in the Democratic Republic of the Congo.

• Human Lactococcus garvieae Bloodstream Infection Complicated by Spondylodiscitis, Germany
  P. Schulz et al.

In Memoriam

• In Memoriam: The Enduring Influence of Nancy J. Cox (1948–2026)
  D. B. Jernigan et al.

Research Letter

• Highly pathogenic avian influenza virus subtype 5 in Brazilian cetaceans: implications for surveillance in threatened species Influenza A Virus in Cetaceans from Brazil
  A. S. Melgarejo et al.

• Implementation and Early Outcomes of Laboratory Proficiency Testing Program for National Wastewater Surveillance System, USA, 2024
  H. Dutcher et al.
• Evaluation of Detection Methods for Wastewater Surveillance of Antimicrobial-Resistant Bacteria from Healthcare Facilities
  E. Warren et al.
• A MultiPartner Effort to Launch and Sustain Wastewater Surveillance in the United States
  J. Yoder et al.