During 2007–2020, we conducted a cross-sectional prevalence study among patients with acute undifferentiated febrile illness to describe the burden and long-term epidemiology of rickettsioses in Cambodia. Serum samples were collected from 10,243 participants, along with epidemiologic data, information on clinical symptoms, demographic characteristics, and risk factors. A total of 802 (7.8%) participants met the definition for acute rickettsial infection after ruling out malaria, influenza, dengue, and chikungunya; 557 (5.4%) cases were typhus, 154 (1.5%) spotted fever, and 136 (1.3%) scrub typhus. Overall seroprevalence was 18.1% (1,857/10,243). Increased age, residence in urban settings, and recent travel to forests were significantly associated with rickettsial infection. Symptoms significantly associated with infection included rash, vomiting, and skin lesions. Our results confirm the underlying burden of rickettsioses and associated risk factors in Cambodia and highlight the need for accessible diagnostics and clinical guidance that consider rickettsioses when treating persons with acute undifferentiated febrile illness.

Spiroplasma ixodetis has been reported to cause the rare combination of cataract and uveitis in infants. Through a retrospective analysis of available literature and additional unpublished cases, we identified 28 eyes from 18 infants from 8 countries in Europe with cataracts and intraocular inflammation. The cataracts were bilateral in 55.6%, unilateral in 44.4%, and progressive in 46.4% of patients. Granulomatous anterior uveitis was found in all infants. Presence of S. ixodetis was supported by PCR (positive in 89.3% of eyes tested), transmission electron microscopy (positive in 90% of eyes tested), or culture of aspirated lens material (positive in 87.5% of eyes tested). Treatment with macrolide antimicrobial drugs, corticosteroids, and lensectomy appeared to be effective. Two patients had a recurrence of the uveitis after lens extraction and needed prolonged treatment. To increase awareness of S. ixodetis, we suggest its inclusion with the organisms of the TORCH acronym.

In the aftermath of 2 extreme weather events in 2022, Malawi experienced a severe cholera outbreak; 59,325 cases and 1,774 deaths were reported by March 31, 2024. We generated 49 Vibrio cholerae full genomes from isolates collected during December 2022–March 2023. Phylogenetic and phylogeographic methods confirmed that the Malawi outbreak strains originated from Pakistan’s 2022 cholera outbreak. That finding aligns with substantial travel between the 2 countries. The estimated most recent ancestor of this lineage was from June–August 2022, coinciding with Pakistan’s floods and cholera surge. Our analysis indicates that major floods in Malawi contributed to the outbreak; reproduction numbers peaked in late December 2022. We conclude that extreme weather events and humanitarian crises in Malawi created conditions conducive to the spread of cholera, and population displacement likely contributed to transmission to susceptible populations in areas relatively unaffected by cholera for more than a decade.

In Europe, highly pathogenic avian influenza (HPAI) virus circulates in avian wildlife, undergoing frequent reassortment, sporadic introductions in domestic birds, and spillover to mammals. An H5N1 clade 2.3.4.4b reassortant, EA-2023-DG, affecting wild and domestic birds was detected in western Europe in November 2023. Six of its RNA segments came from the EA-2021-AB genotype, but the polymerase basic 2 and polymerase acidic segments originated from low pathogenicity avian influenza viruses. Discrete phylogeographic analyses of concatenated genomes and single polymerase basic 2 and polymerase acidic segments suggested reassortment in summer 2023 near the southwestern Baltic Sea. Subsequent continuous phylogeographic analysis of all concatenated EA-2023-DG genomes highlighted circulation in northwestern Europe until June 2024 and long-distance dispersal toward France, Norway, England, Slovakia, Switzerland, and Austria. Those results illustrate the value of phylodynamic approaches to investigate emergence of novel avian influenza virus variants, trace their subsequent dispersal history, and provide vital clues for informing outbreak prevention and intervention policies.

We investigated epidemiologic and molecular characteristics of healthcare-associated (HA) and community-associated (CA) Clostridioides difficile infection (CDI) among adult and pediatric patients in Canadian Nosocomial Infection Surveillance Program hospitals during 2015–2022. Of 30,824 reported CDI cases, 94.9% (29,250/30,824) were among adult (73.2% HA; 26.8% CA) and 5.1% (1,574/30,824) pediatric (77.6% HA; 22.4% CA) patients. During the study period, adult HA CDI rates decreased by 19.9% and CA CDI rates remained stable; pediatric HA CDI rates decreased by 29.6% and CA CDI decreased by 58.3%. Ribotype (RT) 106 was most common among both groups and replaced RT027 as the predominant strain type. RT027 was most associated with adult patients, HA acquisition, severe CDI, and severe outcomes. Moxifloxacin resistance was higher in adult than pediatric cases; clindamycin and rifampin resistance rates were similar between groups. Continued national surveillance is integral to understanding the epidemiology of adult and pediatric CDI in Canada and informing prevention efforts.

To evaluate non–H. pylori Helicobacter (NHPH) infections in Japan, we enrolled 673 consecutive patients who underwent gastric endoscopy during annual medical checkups at 4 hospitals during April 2022–February 2023. We collected intragastric fluid and serum samples to detect NHPH infection by PCR and serologic tests. The prevalence of NHPH was 3% (20/673); 70% (14/20) of patients were infected with H. suis and 30% (6/20) with non–H. suis NHPH species. All 14 H. suis–infected patients were men and had a history of pork offal ingestion. Among non–H. suis NHPH-infected patients, 50% (3/6) owned pet cats, whereas only 22% (145/667) of other patients owned cats. Endoscopic evaluation revealed marbled crack-like gastritis was present in 93% (13/14) of H. suis–infected patients, a significantly higher prevalence than for H. pylori–infected (28.6%) and H. pylori eradication therapy (27.6%) groups. Pork offal ingestion and having pet cats increase risk for Helicobacter spp. infections.

In 2023, an outbreak of highly pathogenic avian influenza occurred among critically endangered California condors (Gymnogyps californianus), and >21 died. We evaluated safety, immunogenicity, vaccination strategies, and correlates of antibody response of an influenza vaccine for poultry in black vultures (Coragyps atratus) and then California condors. We noted differences in antibody titers between vaccinated and unvaccinated birds (vultures p<0.004; condors p­<0.02) but no adverse effects of vaccination. All vaccinated vultures and 80% of vaccinated condors showed maximum measured antibody response within the published range associated with survival of vaccinated and virally challenged chickens. We noted weak evidence of higher antibody responses for birds given two 0.5-mL vaccines versus those given one 1-mL vaccine but no correlation between antibody titers and sex for either species or between antibody titers and bone lead concentrations in vultures. Our results prompted initiation of a vaccination program for condors that could reduce spread of this disease among highly threatened species.

The ongoing outbreaks of mpox highlight the urgent need for a rapid and low-cost diagnostic test to accurately detect and control this emerging disease. We estimated the analytical sensitivity using viral culture of the monkeypox virus clade IIb lineage B1 and clinical diagnostic performance of 3 antigen detection rapid diagnostic tests (Ag-RDT) by using skin swab samples and upper-respiratory swab samples from mpox patients in the Democratic Republic of the Congo and the United Kingdom. The analytical limit of detection was 1.0 × 10⁴ plaque-forming units/mL, fulfilling World Health Organization recommendations. Specificity of the 3 Ag-RDTs was 100%, but sensitivity was estimated at 0.00%–15.79% using skin samples and 0.00% using respiratory samples. None of the 3 Ag-RDTs reached the World Health Organization’s target clinical sensitivity, and we do not recommend them as diagnostic or screening tools for suspected mpox cases. Accurate Ag-RDTs for mpox diagnosis remain urgently needed.

Dengue is a major cause of illness among local populations and travelers in dengue-endemic areas, particularly those who stay for an extended period. However, little is known about dengue risk among expatriates and other long-term travelers. We used catalytic models of force of infection to estimate time to 60% dengue virus (DENV) seropositivity for a cross-section of expatriates living in Bangkok and Pattaya, Thailand. Our model adjusted for daily time spent outside, years not exposed to DENV, sex, living environment, and use of mosquito repellent, nets, long sleeves, and air conditioning. We estimated an adjusted annual force of infection of 0.014 (95% CI 0.003–0.054) per year spent in dengue-endemic areas (67.3 years to 60% seropositivity), below that of local populations. Our findings suggest that expatriates have a DENV exposure profile distinct from locals and short-term travelers and should likely be considered independently when developing vaccine and prevention recommendations.

We conducted a multicenter, observational, 12-month follow-up study to identify the extended health burden of severe COVID-19 pneumonia by characterizing long-term sequelae of acute infection in participants previously enrolled in clinical trials for severe COVID-19 pneumonia requiring hospitalization. Overall, 134 (77.5%) of 173 participants completed the study. At 12 months, 51 (29.5%) participants reported cough, 60 (34.7%) reported dyspnea, 56 (32.4%) had residual lung texture abnormalities on high-resolution computed tomography scans, 26 (15.0%) had impaired forced vital capacity, 52 (30.1%) had cognitive impairment, and 77 (44.5%) reported fatigue. Disease severity during acute infection and age were associated with persistent lung texture abnormalities; history of hypertension was associated with higher prevalence of fatigue and more frequent dyspnea and cough; and age and obesity were associated with long-term cognitive impairment. Our findings underscore the long-term health burden of severe COVID-19 pneumonia, reinforcing the importance of regular monitoring in older persons and those with underlying illnesses.

Histoplasmosis is one of the most common pulmonary mycosis diseases in the world. Genome sequencing has revealed that Histoplasma, the cause of histoplasmosis, is composed of several phylogenetic species. The genetic diversity of the pathogen remains largely unknown, especially in the tropics. We sequenced the genomes of 91 Histoplasma isolates from the Amazon basin of South America and used phylogenomics and population genetic evidence to measure the genetic variation of the genus in South America. We report a previously unidentified clade of Histoplasma endemic to the Amazon basin. The lineage is widespread across the continent and contains 5 lineages that are sufficiently differentiated to be considered phylogenetic species. We found the geographic range of those lineages is largely but not completely overlapping. Finally, we found that the patient median age and sex ratio differs among species, suggesting differences in the epidemiology of histoplasmosis caused by each Histoplasma lineage.

Oropouche virus (OROV), historically endemic to the Amazon, had spread to nearly all Brazil states by 2024; Espírito Santo emerged as a transmission hotspot in the Atlantic Forest biome. We characterized the epidemiologic factors driving OROV spread in nonendemic southeast Brazil, analyzing environmental and agricultural conditions contributing to viral transmission. We tested samples from 29,080 suspected arbovirus-infected patients quantitative reverse transcription PCR for OROV and dengue, chikungunya, Zika, and Mayaro viruses. During March‒June 2024, the state had 339 confirmed OROV cases, demonstrating successful local transmission. Spatial analysis revealed that most cases clustered in municipalities with tropical climates and intensive cacao, robusta coffee, coconut, and pepper cultivation. Phylogenetic analysis identified the Espírito Santo OROV strains as part of the 2022–2024 Amazon lineage. The rapid spread of OROV outside the Amazon highlights its adaptive potential and public health threat, emphasizing the need for enhanced surveillance and targeted control measures.

We report a case of iatrogenic Creutzfeldt-Jakob disease (iCJD) after a 48.3-year incubation period in a patient treated with cadaveric human growth hormone. iCJD was pathologically confirmed; genetic analysis was negative for pathogenic mutations. Clinicians should consider iCJD in patients with progressive neurologic signs who had received cadaveric human growth hormone treatment.

Murine typhus, a fleaborne bacterial disease caused by Rickettsia typhi, has reemerged and spread in the United States. We tested spinosad, an oral flea preventive, in opossum flea reservoirs. Spinosad killed 98% of fleas infesting opossums. Oral preventives could control fleas in host species and curb murine typhus spread to humans.

We report an OXA-204–producing Pseudomonas guariconensis clinical isolate in Tunisia, proving the spread of OXA-48 variants beyond Enterobacterales. The bla_OXA-204 gene was carried on a 119-kb chromosomally integrated plasmid fragment, along with multiple additional resistance genes. Surveillance, diagnostic tools, and antimicrobial drug access are needed to mitigate spread of carbapenem-resistant pathogens.

We tested cross-neutralization against highly pathogenic avian influenza A(H5N1) virus in adults vaccinated with 2021–2023 seasonal quadrivalent influenza vaccine in the United Kingdom. Seasonal quadrivalent influenza vaccines are unlikely to protect vulnerable persons against severe H5N1 disease during widespread transmission. Enhanced measures are needed to protect vulnerable people from H5N1 virus infection.

Mycoplasma arginini is a bacterium primarily found in animals and is seldom reported in human infections. We identified M. arginini infection in a severely immunocompromised kidney transplant recipient in Slovenia. Clinicians should be aware of M. arginini’s potential as a pathogen in immunocompromised persons with animal contact.

We conducted a hospital-based cross-sectional study of Plasmodium falciparum in 2017 in southeastern Sudan. Among 257 P. falciparum samples, we found 22% harbored the pfkelch13 R622I mutation and 10.7% showed hrp2/3 gene deletions. Our findings highlight the urgent need for enhanced surveillance of drug- and diagnostic-resistant parasites in the Horn of Africa.

We characterized highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b genotype D1.1 in wild birds and a human in British Columbia, Canada, during 2024. D1.1, the predominant genotype circulating in fall 2024, is a reassortment between Eurasian A3 lineage viruses, introduced to North America in 2022, and North American lineage viruses.

We report 3 cases of dual-genotype Orientia tsutsugamushi infection in Hainan Island, China. Patients exhibited diverse clinical manifestations, including afebrile illness and multiorgan involvement, highlighting the complexity associated with genetic diversity in scrub typhus. Clinicians should maintain heightened suspicion for atypical scrub typhus manifestations in endemic regions.

We describe a pediatric case of recurrent skin infections caused by a Panton-Valentine leukocidin and exfoliative toxin E double-positive methicillin-susceptible Staphylococcus aureus clonal complex 188 clone. Most of the patient’s family members were infected with the same strain, and intrafamilial transmission was strongly suspected. Decolonization procedures were not effective.

Cache Valley virus (CVV), a mosquitoborne virus, can cause neuroinvasive disease in humans and adverse reproductive outcomes in sheep and goats. In 2023, CVV RNA was detected in an aborted lamb from a flock in Arkansas, USA. We conducted a One Health investigation to explore the potential effects of CVV in Arkansas.

Treatment-refractory giardiasis is an emerging clinical problem. Of 4,285 giardiasis cases identified during 2008–2020 in Stockholm, Sweden, 102 (2.4%) were nitroimidazole refractory. Among cases acquired in India, the percentage was high (64/545 [12%]) and increased over time. The region of acquisition needs to be taken into consideration when managing patients.

We report 3 cases of babesiosis in Italy caused by Babesia species that are rarely reported in humans. The circulation of Babesia spp. among vectors, animals, and humans might be more common than previously thought, and babesiosis might be an underdiagnosed and emerging disease in Italy and Europe.

Usutu virus is a zoonotic arbovirus that causes massive mortality in blackbirds. Using a unique longitudinal dataset on the kinetics of virus-specific antibodies in naturally infected wild blackbirds (Turdus merula), we found that individual birds may remain seropositive for >1 year and that reinfection can occur despite low-level virus neutralizing antibodies.

We report fatal tularemia in stranded beluga whales in Cook Inlet, Alaska, USA. Francisella tularensis was detected by nanopore metagenomics, confirmed by quantitative PCR and immunohistochemistry, and characterized as F. tularensis subspecies holarctica by multilocus sequence typing. Our findings should be considered when assessing biosecurity and marine mammal health in the North Pacific.

We report nosocomial Plasmodium falciparum malaria in Spain, which was confirmed microbiologically and genomically. Transmission occurred through insufficiently disinfected reusable syringe lead shielding during thyroid scintigraphy. Genomic analysis showed high similarity between isolates from index and source cases. Strict biosafety measures are needed in healthcare settings to prevent malaria transmission.

Influenza A(H5N1) viruses have been detected in US dairy cow herds since 2024. We assessed the pathogenesis, transmission, and airborne release of A/Michigan/90/2024, an H5N1 isolate from a dairy farm worker in Michigan, in the ferret model. Results show this virus caused airborne transmission with moderate pathogenicity, including limited extrapulmonary spread, without lethality.

We monitored mosquitoes in 3 bus stations in Bogota, Colombia, located at 2,625 m above sea level. During December 2023–January 2024, we collected 27 larvae and 1 adult female Aedes aegypti mosquitoes at 1 station. Detection of Ae. aegypti mosquitoes in Bogota is a call to continue monitoring mosquitoes at stations.

We report a Dirofilaria repens nematode infection in a woman in Italy who sought care for a fast-creeping lesion within her subcutaneous facial tissue. Dirofilariosis should be included in differential diagnosis of subcutaneous nodules or creeping lesions. This case highlights the need for controlling canine dirofilarioses to mitigate zoonotic risk.

Informed by passive tick surveillance, we collected questing Haemaphysalis longicornis ticks from southwestern Connecticut, USA. Of 445 ticks tested by PCR, 3 nymphs were positive: 1 for Ehrlichia chaffeensis and 2 for Borrelia burgdorferi. This finding highlights the enduring public health challenges of invasive ticks and associated pathogens.

We used PCR, Sanger sequencing, and phylogenetic analysis to identify Wesselsbron virus (WSLV) clade 1 in sick camels from Borana Zone, Ethiopia. Although WSLV primarily infects sheep and cattle, its pathogenicity in camels remains unclear. Camel farmers in the region should be aware of WSLV and its health effects in camels.

We found the zoonotic nematode, Baylisascaris procyonis, in a common raccoon (Procyon lotor) in Mexico. Expansion of raccoons into human-dominated regions might increase the risk of B. procyonis infections in humans. Increased surveillance and healthcare provider awareness of baylisascariasis in Mexico will be needed to prevent those infections in humans.