Emerging Infectious Diseases - CDC (original) (raw)

Outbreak of Legionnaires’ Disease Linked to Newly Installed Residential Water Heaters, the Netherlands, 2022–2023 [PDF - 863 KB - 7 pages]

D. Reukers et al.

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.

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Trichinellosis Outbreak Linked to Undercooked Bear Jerky, North Carolina, USA, 2024 [PDF - 1.12 MB - 5 pages]

C. D. Gowler et al.

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.

Emerging Risk for Human T-Cell Leukemia Virus Type 1 Transmission with HIV-Positive Breastfeeding Support [PDF - 478 KB - 6 pages]

A. Meybeck et al.

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 [PDF - 552 KB - 7 pages]

T. Yang et al.

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%.

Neurosurgical Biopsy and Resection for Diagnosis and Treatment of Balamuthia mandrillaris Amebic Encephalitis, United States [PDF - 2.17 MB - 9 pages]

B. Rubbab et al.

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.

Adeno-Associated Virus Type 2 and Human Adenovirus Species F Type 41 Co-infection Associated with Acute Severe Hepatitis in Children, California, USA [PDF - 1.47 MB - 8 pages]

R. Zhuo et al.

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.

National Surveillance of Enterovirus D68 Upsurge, France, 2024 [PDF - 4.29 MB - 12 pages]

M. Jeannoël et al.

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.

Clinical Predictors of Fatal Outcomes from Human Leptospirosis, Thailand, 2015–2024 [PDF - 1.94 MB - 10 pages]

U. Limothai et al.

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 was observed in all patients with fatal cases for whom genomic data were available. 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.

Prognostic Value of PCR Cycle Threshold Value in Crimean-Congo Hemorrhagic Fever, Iraq, 2022–2023 [PDF - 2.68 MB - 9 pages]

R. I. Khaleel et al.

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 [PDF - 2.97 MB - 10 pages]

L. Anettová et al.

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 have 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.

Molecular Epidemiology of Skin-Dwelling Filariae and Risk Factors for Mansonella streptocerca Infection, Gabon [PDF - 799 KB - 10 pages]

C. Sicard et al.

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.

Investigation of Donor-Transmitted Strongyloides stercoralis Infections in Solid Organ Transplant Recipients, United States, 2012–2024 [PDF - 1.15 MB - 8 pages]

K. R. Gainor et al.

Strongyloides stercoralis is a parasitic nematode endemic in tropical and subtropical regions, including parts of the southeastern United States, that can be transmitted via organ donation. As of October 2025, the Organ Procurement and Transplant Network implemented new policy for screening in deceased US organ donors to reduce the risk for donor-derived Strongyloides infection. To assess the potential effect of policy changes, we reviewed investigations of suspected transplant-related strongyloidiasis in the United States conducted by the Centers for Disease Control and Prevention and partners for solid organ transplants occurring during 2012–2024. During that period, 21 proven donor-derived strongyloidiasis cases originated from 15 unscreened donors. Of donors who were screened, 31 seropositive donors resulted in ivermectin prophylaxis for 77 recipients, none of whom had disease develop. Our findings support the effectiveness of universal organ donor screening and prophylactic ivermectin treatment of recipients to prevent donor-derived Strongyloides infection.

Discovery of Cinchona as Antimalarial, Viceroyalty of Peru, Circa 1630 [PDF - 3.51 MB - 9 pages]

J. Rojas-Jaimes et al.

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.

Phormia regina Fly as Vector for Ignatzschineria spp. Bacteremia in Persons Experiencing Homelessness, Canada, 2025 [PDF - 1.58 MB - 5 pages]

E. Finlayson-Trick et al.

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.

Cat-Scratch Disease Associated with Acute Hearing Loss, Israel [PDF - 469 KB - 4 pages]

M. Yakubovsky et al.

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.

Cluster of Human Tanapox Cases in Wildlife Reserve, South Africa, 2024 [PDF - 982 KB - 4 pages]

M. Birkhead et al.

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.

Vascularized Iris Mass as Sentinel Manifestation of Syphilis in Patient with HIV Infection, Spain, 2025 [PDF - 1.15 MB - 4 pages]

M. Caminal-Caramés et al.

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.

Nipah Virus Shedding in Urine from Fruit Bats, Sri Lanka, 2018–2019 [PDF - 1.27 MB - 5 pages]

C. Kohl et al.

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.

Recurrent Facial Folliculitis Caused by Klebsiella aerogenes Sequence Type 117 in Men who Have Sex with Men [PDF - 1.65 MB - 5 pages]

G. Monsel et al.

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.

Trends in Congenital Syphilis Cases by Maternal Country of Birth, Spain, 2016–2024 [PDF - 741 KB - 5 pages]

V. Hernando et al.

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.

Household Transmission of Enterovirus D68, Washington and Oregon, United States, 2022–2024 [PDF - 977 KB - 6 pages]

P. Roychoudhury et al.

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.

Angiostrongylus cantonensis Rat Lungworm Detected in Rats, Madagascar, 2022–2023 [PDF - 2.03 MB - 5 pages]

S. F. Randrianarisoa et al.

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.

New World Ocular Dirofilariasis Caused by Dirofilaria repens Infection, United States [PDF - 900 KB - 3 pages]

B. J. Glasgow et al.

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.

Human Pulmonary Dirofilariasis, North Queensland, Australia, 2023 [PDF - 1.00 MB - 3 pages]

K. Murray et al.

Dirofilaria nematodes, a common cause of canine filarial disease, are increasingly recognized as emerging human pathogens. We report a case of human pulmonary dirofilariasis in the lung of a man from Northern Australia with pulmonary adenocarcinoma. This case highlights the risk for zoonotic transmission in regions with high canine heartworm prevalence.

Detection of and Early Genomic Insights into Chikungunya Virus, Bolivia, 2025 [PDF - 992 KB - 4 pages]

J. Chuquimia Valdez et al.

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.

Ophthalmomyiasis Outbreak Caused by Oestrus ovis Infection, Algeria, 2025 [PDF - 1.64 MB - 4 pages]

Y. Zeng et al.

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.

Molecular Confirmation of Autochthonous Taenia saginata Infection, Timor-Leste, 2019 [PDF - 873 KB - 3 pages]

H. Jin et al.

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.

Emergence of West African Human T-Lymphotropic Virus 1aC Subgroup, Brazilian Amazon [PDF - 1.47 MB - 5 pages]

J. de Melo Silva et al.

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.

Neurologic Alveolar Echinococcosis in Postpartum Zoo-Housed Gorilla, the Netherlands, 2024 [PDF - 874 KB - 4 pages]

L. Derks et al.

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 [PDF - 780 KB - 4 pages]

M. J. Yabsley et al.

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.

Ancylostoma ceylanicum Hookworm, Rural Papua New Guinea, 2020 [PDF - 401 KB - 3 pages]

J. L. Scott et al.

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.

Autochthonous Neurocysticercosis Brain Lesions Mimicking Metastatic Disease, Spain [PDF - 461 KB - 2 pages]

E. Hernández-Sánchez et al.

Autochthonous neurocysticercosis is exceptionally rare in Western Europe. We describe multiple brain lesions, initially mimicking metastases, 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 cestode transmission risks and diagnostic challenges in nonendemic regions.

Chikungunya Outbreak, Cuba, July 2025 [PDF - 2.06 MB - 4 pages]

M. M. Perez et al.

Chikungunya transmission was confirmed in Perico, Matanzas Province, Cuba. Initial research confirmed the presence of East/Central/South African genotype related to Brazil 2025 strains in serum samples and in Aedes aegypti mosquito pools from transmission areas. Our findings underscore the need for surveillance and signal potential spread to other regions.

Fasciolopsis buski [PDF - 545 KB - 1 page]

M. Calatri

Inconsistent Strategies to Mitigate the Effects of Batrachochytrium salamandrivorans, Europe [PDF - 887 KB - 8 pages]

P. Böning et al.

Emerging infectious diseases are one of the biggest challenges in a globalized world. To date, resources have been allocated to prevent and control the spread of zoonotic and livestock pathogens. We argue that, in line with the One Health approach, equitable efforts, financial resources, attention, and coordination are required for wildlife-only pathogens to halt biodiversity loss. Deploying the amphibian fungus Batrachochytrium salamandrivorans as a model, we demonstrate the unbalanced efforts among countries in Europe regarding surveillance, disease response, prevention, public outreach, and research. We compare investments with _B. salamandrivorans_–free countries such as the United States, concluding that structural resources are urgently needed to curb the effects of this fungus within Europe and beyond. We encourage dialogue among authorities, researchers, and stakeholders and propose a coordinated European Union–level program of €6–10 million over 5–7 years to implement B. salamandrivorans action plans and define structural funding requirements for future wildlife disease mitigation.

Jimmy Carter and Eradication of Guinea Worm Disease [PDF - 1.36 MB - 3 pages]

S. O’Connor et al.

Medscape, LLC is pleased to provide online continuing medical education (CME) for selected journal articles, allowing clinicians the opportunity to earn CME credit. In support of improving patient care, these activities have been planned and implemented by Medscape, LLC and Emerging Infectious Diseases. Medscape, LLC is jointly accredited by the Accreditation Council for Continuing Medical Education (ACCME), the Accreditation Council for Pharmacy Education (ACPE), and the American Nurses Credentialing Center (ANCC), to provide continuing education for the healthcare team.

CME credit is available for one year after publication.

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Trichinellosis Outbreak Linked to Undercooked Bear Jerky, North Carolina, USA, 2024 [PDF - 1.12 MB - 5 pages]

C. D. Gowler et al.

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.

Expires 5/29/2027

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Cerebrospinal Fluid Findings among Patients with Anaplasmosis and Central Nervous Involvement, Minnesota and Wisconsin, USA [PDF - 597 KB - 7 pages]

I. Dumic et al.

Anaplasmosis, an emerging tickborne zoonosis, infrequently involves the central nervous system, and cerebrospinal fluid (CSF) profiles of anaplasmosis remain poorly characterized. We conducted a multisite retrospective study of patients hospitalized with anaplasmosis during November 1, 2014–November 29, 2024, in Minnesota and Wisconsin, USA, a hyperendemic region. Included patients had anaplasmosis confirmed by PCR on blood samples, exhibited neurologic symptoms, and had lumbar puncture procedures. Ten hospitalized patients met inclusion criteria, 6 with meningitis, 3 with meningoencephalitis, and 1 with encephalitis. CSF findings were within reference ranges for 5 patients; 4 patients demonstrated mild lymphocytic pleocytosis, but glucose and protein levels were within reference ranges. One patient underwent a traumatic lumbar puncture resulting in neutrophilic pleocytosis. CSF abnormalities did not correlate with neurologic severity, suggesting a cytokine-mediated process rather than direct central nervous system infection. All patients rapidly improved with doxycycline, highlighting the need for early recognition and empiric therapy for anaplasmosis.

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Frequency and Duration of Diagnostic Delays Associated with Coccidioidomycosis and Risk Factors for Missed Diagnoses, United States [PDF - 997 KB - 10 pages]

D. D. Barber et al.

Diagnosis of coccidioidomycosis is challenging and requires a high index of clinical suspicion. We estimated the incidence and duration of, and risk factors associated with, diagnostic delays and missed opportunities in the diagnosis of coccidioidomycosis. We conducted a retrospective analysis of health insurance claims data in the United States during 2001–2022 included in the Merative MarketScan Databases. Using a case-crossover design and a bootstrapping approach, we estimated the number of excess visits for coccidioidomycosis-related symptoms before diagnosis. We also evaluated potential factors associated with delay. We estimated that almost 60% of patients experienced >1 missed opportunity for diagnosis; the average diagnostic delay was 29.69 (95% CI 28.25–31.18) days. Missed opportunities were predominantly observed in outpatient settings (73%) and were significantly associated with older age, rural residence, underlying pulmonary conditions, and prescriptions for antibiotics or inhalers. Diagnostic delays for coccidioidomycosis are common, and addressing such delays could improve clinical outcomes.

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Pediatric Meningoencephalitis Cluster Caused by Snowshoe Hare Virus, Whistler, British Columbia, Canada, 2024 [PDF - 790 KB - 7 pages]

F. Ali et al.

Snowshoe hare virus (SSHV) is an arbovirus in the California serogroup known to circulate throughout Canada and northern latitudes of the United States. The clinical spectrum of SSHV infection ranges from asymptomatic or mild febrile illness to neuroinvasive disease; neuroinvasive disease occurs more often in children and young adults. We describe a cluster of confirmed and probable SSHV meningoencephalitis cases in 3 children from Whistler, British Columbia, Canada, in the summer of 2024. We highlight the shared epidemiology, clinical manifestations, serologic diagnostic methods, and outcomes for the cases. All 3 children acquired the infection locally and made a full recovery. This case series suggests underrecognized SSHV infection prevalence that warrants enhanced surveillance and review of existing diagnostic algorithms. California serogroup viruses, including SSHV, should be recognized as a potential cause of neuroinvasive disease in North America during mosquito season, particularly when initial diagnostic testing is inconclusive.

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Blastomyces Urine Antigen Testing for Active Case Identification During a Blastomycosis Outbreak [PDF - 652 KB - 8 pages]

A. W. O’Connor et al.

Blastomyces urine antigen testing is a sensitive blastomycosis diagnostic method, but its utility for active case identification during outbreaks is unknown. We evaluated urine antigen testing for identifying blastomycosis cases during a 2023 outbreak at a Michigan, USA, paper mill and assessed demographic and clinical factors associated with test positivity. Approximately 2 months after the outbreak was recognized, we collected work and health information for 603 employees; 95% (n = 578) underwent urine antigen testing and 9% (n = 52) tested positive, including 25 previously undetected cases. Blastomycosis-like symptoms were associated with test positivity (p<0.001), but 10% of employees with positive results were asymptomatic. Recent hospitalization for blastomycosis was associated with test positivity (p = 0.02) and higher antigen levels. Further research into urine antigen testing is needed clarify its suitability for detecting mild and asymptomatic infections during outbreak investigations. Urine antigen testing had high acceptability among employees and effectively identified additional cases.

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Retrospective Case Series of Ocular Lyme Disease, 1988–2025 [PDF - 1.95 MB - 6 pages]

J. Bellafiore et al.

Reports of ocular manifestations of Lyme disease (LD) are uncommon, and signs and symptoms may be overlooked by physicians. We conducted a retrospective case series of ocular LD reported during 1988–2025. Among 27 published reports in PubMed, we noted that, in 38 cases, the most common ocular manifestation was uveitis, representing 45% of cases, followed by optic neuritis and cranial nerve palsies (including trochlear and abducens). Not all cases met Centers for Disease Control and Prevention surveillance guidelines for LD, given that some case reports were published before the current guidelines. Cases that provided microbiologic proof were 2 anterior uveitis cases, 1 case of anterior uveitis with abducens’s nerve palsy, 1 case of intermediate uveitis, and 1 case of intranuclear ophthalmoplegia. Ocular LD can have a broad variety of manifestations; therefore, physicians should be aware of those manifestations and obtain microbiologic proof for a more definitive diagnosis and epidemiologic value when possible.

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Group A Streptococcus Meningitis, United States, 1997–2022 [PDF - 1.23 MB - 11 pages]

P. A. Hawkins et al.

Group A Streptococcus (GAS) causes a variety of diseases in humans but is not widely appreciated as a cause of meningitis. During 1997–2022, ten sites participating in the Active Bacterial Core Surveillance network in the United States identified GAS meningitis cases. We calculated annual incidence and case-fatality rates (CFRs) for 320 of those cases and determined antimicrobial resistance by whole-genome sequencing. Annual incidence of GAS meningitis ranged from 0.02 to 0.07 cases/100,000 persons. Children <1 year of age had the highest average annual incidence, 0.23 cases/100,000 children. GAS meningitis had a higher CFR (19.4%) than meningitis caused by group B Streptococcus, Streptococcus pneumoniae, Neisseria meningitidis, or Haemophilus influenzae. Clindamycin resistance among GAS meningitis isolates increased from 3.2% during 1997–2002 to 17.7% during 2018–2022. Clinicians should be aware that meningitis is an uncommon but severe manifestation of invasive GAS and has a higher CFR than more established meningitis etiologies.

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Pregnancy Outcomes after Exposure to Tuberculosis Treatment in Phase 3 Clinical Trial, 2016–2020 [PDF - 759 KB - 10 pages]

E. V. Kurbatova et al.

A previous study demonstrated noninferior efficacy of 4-month rifapentine/moxifloxacin regimen for tuberculosis (TB) treatment compared with the standard regimen. We analyzed pregnancy outcomes of women who became pregnant during the study. Among 740 women, 97 (13.1%) became pregnant. Of 102 pregnancies (in 97 participants), 30 (29.4%) participants were exposed to study drugs. Fetal loss was reported for 3/13 (23.1%) in the control regimen, 1/9 (11.1%) in the rifapentine/moxifloxacin regimen, and 1/8 (12.5%) in the rifapentine regimen. Among 21 live births in exposed pregnancies (7 in each arm), 1 infant with a congenital anomaly was reported in a participant on the rifapentine regimen. Among women receiving a short rifapentine/moxifloxacin regimen for tuberculosis who became pregnant, we observed no elevated rates of fetal losses or congenital anomalies.

Expires 10/17/2026

Medscape CME Activity

Haematospirillum jordaniae Infections after Recreational Exposure to River Water, Pennsylvania, USA, 2020 [PDF - 885 KB - 7 pages]

M. Dulcey et al.

Haematospirillum jordaniae was first identified as a human pathogen in 2016. In this article, we describe 4 patients who had H. jordaniae infections identified in 2020 and who had temporally and spatially linked environmental exposures. Three of the 4 patients reported leg injuries while participating in recreational river water activities in south-central Pennsylvania, USA. In 2024, we detected H. jordaniae in river samples collected at locations identified during patient interviews. All patients sought emergency department services for clinical assessment; however, the causative bacterial isolate was not initially identified. H. jordaniae was identified as the bacterial cause months after patient treatment and discharge. Although H. jordaniae infections are considered rare, the true occurrence is unknown. Additional information about the organism’s ecology and environmental seasonality could guide public health messaging and increase awareness among healthcare providers.

Expires 9/23/2026

Medscape CME Activity

Reptile Exposure in Human Salmonellosis Cases and Salmonella Serotypes Isolated from Reptiles, Ontario, Canada, 2015–2022 [PDF - 1.72 MB - 10 pages]

K. Paphitis et al.

Reptile-associated outbreaks of human Salmonella infections are increasing in Canada, coinciding with a rise in the popularity of reptiles as pets. We conducted a retrospective analysis of surveillance data for human Salmonella case-patients in Ontario during 2015–2022. We compared serotypes and reptile types for those reporting domestic reptile or amphibian exposure with veterinary Salmonella isolates reported during the same period. Case-patients commonly reported contact with reptile types from which Salmonella was most frequently isolated. Some serotypes from human case-patients were closely associated with contact with specific reptile types, including Salmonella Paratyphi B biovar Java (Salmonella Paratyphi B variant L (+) tartrate +) with snakes, Salmonella Agbeni with turtles, and Salmonella Cotham, Salmonella Chester, and Salmonella Tennessee with bearded dragons. Salmonella was most likely to be reported from reptiles fed a carnivorous diet. Education of reptile owners could help promote proper veterinary care and reduce transmission of zoonotic infections.

Expires 9/17/2026

Medscape CME Activity

Recent Systemic Antifungal Exposure and Nonsusceptible Candida in Hospitalized Patients, South Africa, 2012–2017 [PDF - 1.11 MB - 11 pages]

C. Rabault et al.

Candida bloodstream infections, and their increasing antifungal resistance, are a global concern. In this cross-sectional study, we analyzed 2,443 culture-confirmed candidemia cases reported in South Africa during 2012–2017 to assess the effect of previous antifungal exposure on nonsusceptible Candida infection. We classified cases by species resistance profile and patient’s antifungal use within 14 days before infection. We found that 48% of cases were caused by nonsusceptible species, and 20% of patients had prior antifungal exposure, mainly to fluconazole. In patients >90 days of age, prior antifungal use was significantly associated with nonsusceptible Candida bloodstream infection (adjusted OR 2.02, 95% CI 1.43–2.87; p<0.001), with species-specific effects. No such association was found in neonates and young infants, for whom hospital transmission appeared more influential. Our findings underscore the need for targeted antifungal stewardship and enhanced infection prevention to mitigate antifungal resistance in South Africa.

Expires 8/22/2026

Medscape CME Activity

Rickettsioses as Underrecognized Cause of Hospitalization for Febrile Illness, Uganda [PDF - 1.22 MB - 10 pages]

P. W. Blair et al.

The complexity of rickettsial serodiagnostics during acute illness has limited clinical characterization in Africa. We used archived samples from sepsis (n = 259) and acute febrile illness (n = 70) cohorts in Uganda to identify spotted fever and typhus group rickettsiae by using immunofluorescence assay and clinically validated rRNA reverse transcription PCR (RT-PCR). Among 329 participants, 10.0% had rickettsial infections (n = 33; n = 20 identified with immunofluorescence assay and n = 13 by RT-PCR). Serum rRNA RT-PCR was 75.0% (95% CI 42.8–94.5%) sensitive and 91.2% (95% CI 85.8–95.1%) specific. Thrombocytopenia was more common among patients with rickettsial infections than with other nonmalarial infections (adjusted odds ratio 3.7; p = 0.003). No participants were on a tetracycline antimicrobial drug at admission. rRNA RT-PCR is a promising diagnostic strategy for identifying acute rickettsial infections. Doxycycline should be included in empiric antimicrobial drug regimens for nonmalarial febrile illness in this region.

Expires 8/21/2026

Medscape CME Activity

Severe Group A Streptococcus Infection among Children, France, 2022–2024 [PDF - 1.01 MB - 10 pages]

M. Colomina et al.

Suggested citation for this article

Sierra Colomina M, Flamant A, Le Balle G, Cohen JF, Berthomieu L, Leteurtre S, et al. Severe group A Streptococcus infection among children, France, 2022–2024. Emerg Infect Dis. 2025 Sep [_date cited_]. https://doi.org/10.3201/eid3109.250245

Group A Streptococcus infections have increased in Europe since September 2022. The French Pediatric Intensive Care and French Pediatric Infectious Diseases expert groups conducted a retrospective and prospective study of children who had severe group A Streptococcus infections during September 1, 2022–April 1, 2024, across 34 hospitals in France. A total of 402 pediatric patients (median age 4 [interquartile range 2–7.5] years; 42% girls, 58% boys) were enrolled. Cases were characterized by a low proportion of severe skin and soft tissue infections (16%), predominance of severe upper and lower respiratory tract infections (55%), and a 3.5% case-fatality rate. In multivariate analysis, hydrocortisone, corticosteroid, and vasopressor therapies were significantly associated with major sequelae or death. Molecular analysis revealed emm1 (73.0%) and emm12 (10.8%) strains; the M1UK clone represented 50% of emm1 strains. Clinicians, researchers, and public health authorities must collaborate to mitigate the effects of GAS on child health.

Expires 7/24/2026

Medscape CME Activity

Scheffersomyces spartinae Fungemia among Pediatric Patients, Pakistan, 2020–2024 [PDF - 1.42 MB - 11 pages]

K. Jabeen et al.

Prevalence of emerging fungal infections is increasing, particularly among immunocompromised persons, children, and older persons. We report 108 cases of Scheffersomyces spartinae infection in pediatric patients from Karachi and other cities in Pakistan, of which 107 were identified from blood cultures. Cultures were initially misidentified as Clavispora lusitaniae by a biochemical assay before speciation as S. spartinae by whole-genome sequencing. All isolates were from children <12 years of age, and >69% were from children <1 month of age. Isolates were genetically distinct across regions of Pakistan; however, genetic diversity was low in isolates from patients in Karachi and nearby Nawabshah and had median differences of just 9 pairwise nucleotide variants. This study demonstrates S. spartinae is a potentially emerging pathogen in neonates and young infants in Pakistan. The findings highlight the limitations of phenotypic identification for detecting emerging fungal infections and underscore the value of molecular identification approaches.

Expires 7/23/2026

Medscape CME Activity

Emergence of Clade Ib Monkeypox Virus—Current State of Evidence [PDF - 1.99 MB - 10 pages]

P. S. Satheshkumar et al.

Mpox was first identified against the backdrop of the smallpox eradication campaign. Monkeypox virus (MPXV), the causative agent of mpox, has been maintained in animal reservoirs in the forested regions of West and Central Africa as 2 distinct clades; clade I has historically caused more severe infection in Central Africa than clade II, historically found in West Africa. However, rapid reemergence and spread of both MPXV clades through novel routes of transmission have challenged the known characteristics of mpox. We summarize mpox demographic distribution, clinical severity, and case-fatality rates attributed to genetically distinct MPXV subclades and focus on MPXV clade Ib, the more recently identified subclade. Broad worldwide assistance will be necessary to halt the spread of both MPXV clades within mpox endemic and nonendemic regions to prevent future outbreaks.