Articles from Emerging Infectious Diseases

Louseborne Bartonella quintana infections in the United States occur almost exclusively among persons experiencing homelessness because of inadequate access to hygiene resources. Homelessness is increasing, and persons experiencing homelessness can be organ donors, despite barriers to receiving donated organs themselves. Recent reports have documented B. quintana transmission via organs transplanted from donors who had recently experienced homelessness. Those reports demonstrate the threat of severe bartonellosis in immunosuppressed organ transplant recipients after donor-derived B. quintana infection. Addressing the root causes of B. quintana transmission could improve the quality of life for persons experiencing homelessness and simultaneously mitigate risk for donor-derived B. quintana transmission. Interventions include improved access to housing, consistent access to hot water for showers and laundry, early treatment of body lice infestation and B. quintana infection, and B. quintana testing and prophylactic treatment of recipients of organs from donors who have experienced risk factors for B. quintana, including homelessness.

Bartonella quintana infection can cause severe disease that includes clinical manifestations such as endocarditis, chronic bacteremia, and vasoproliferative lesions of the skin and viscera. B. quintana bacteria is transmitted by the human body louse (Pediculus humanus corporis) and is associated with homelessness and limited access to hygienic services. We report B. quintana infection in 2 kidney transplant recipients in the United States from an organ donor who was experiencing homelessness. One infection manifested atypically, and the other was minimally symptomatic; with rapid detection, both recipients received timely treatment and recovered. B. quintana was identified retrospectively in an archived donor hematoma specimen, confirming the transmission link. Information about the organ donor’s housing status was critical to this investigation. Evaluation for B. quintana infection should be considered for solid organ transplant recipients who receive organs from donors with a history of homelessness or of body lice infestation.

An increase in the number of herpes zoster patients has been reported since universal varicella immunization was introduced, perhaps because of reduced opportunities for varicella patients to experience the natural booster effect caused by reexposure. We investigated recent trends of varicella zoster virus (VZV)–related central nervous system (CNS) infections at a university hospital in Japan. We enrolled patients with suspected CNS infection during 2013–2022 and tested cerebrospinal fluid samples by real-time PCR for DNA from 7 human herpesviruses. VZV DNA was the most commonly detected in 62 (10.2%) of 615 patients. Kulldorff’s circular spatial scan statistics demonstrated a significant temporal cluster of patients with VZV-related CNS infections during 2019–2022 (p = 0.008). Among persons with such infections, the percentage with aseptic meningitis was significantly higher during 2019–2022 (86.8%), when the temporal cluster of cases occurred, than during 2013–2018 (50.0%) (p = 0.0029).

Understanding Kazakhstan’s plague history is crucial for early warning and effective health disaster management. We used descriptive-analytical methods to analyze spatial data for human cases in natural plague foci in Kazakhstan during 1926–2003. The findings revealed 565 human cases across 82 outbreaks in Almaty (32.22%), Aktobe (1.59%), Atyrau (4.42%), Mangystau (21.24%), and Kyzylorda (40.53%) oblasts. Before antibiotic drugs were introduced in 1947–1948, major plague outbreaks occurred in 1926, 1929, 1945, 1947, and 1948, constituting 80.7% of human transmission. Plague spread through flea bites, camel handling, wild animal contact, aerosol transmissions, and rodent bites. Patients were up to 86 years of age; 49.9% were male and 50.1% female. Pulmonary cases were reported most frequently (72.4%), and person-to-person infection occurred at an incidence rate of 0.29 cases/10,000 population. Risk increased with human expansion into natural plague foci areas. Swift diagnosis and treatment are essential for curbing plague outbreaks in Kazakhstan.

Bartonella quintana infection can lead to bacillary angiomatosis, peliosis hepatis, chronic bacteremia, and culture-negative endocarditis. Transmitted by the human body louse (Pediculus humanus humanus), B. quintana infection has become an emerging disease in recent decades among persons experiencing homelessness. By using retrospective laboratory surveillance, we identified 5 cases of left-sided, culture-negative B. quintana endocarditis among persons in New York, New York, USA, during January 1, 2020–November 23, 2023. Identifications were made by using molecular assays. All patients experienced unsheltered homelessness in the year before hospitalization. Of those patients, 4 experienced heart failure, 3 renal failure, and 2 embolic strokes; 2 died. Aortic valve replacement occurred in 4 cases. A history of possible body louse infestation was found in 4 cases. Clinicians should consider housing status and history of lice exposure in patients with suspected bartonellosis and have a low threshold for diagnostic testing and empiric treatment in patients experiencing homelessness.

The Ebola virus disease (EVD) outbreak of 2013–2016 was large, leaving in its wake an estimated 17,000 survivors in West Africa. Uveitis is one of the most common ophthalmic manifestations of EVD, but long-term follow-up in the at-risk population is lacking. We conducted a retrospective cross-sectional study of 521 EVD survivors from Sierra Leone who underwent comprehensive ophthalmic examination a median of 1,289 days, or ≈3.5 years, after discharge from Ebola treatment units. The most common ophthalmic findings were cataracts (117 eyes, 11.2%), uveitis (86 eyes, 8.3%), dry eyes (81 eyes, 7.8%), and chorioretinal scar (68 eyes, 6.5%). EVD survivors with cataracts, uveitis, optic neuropathy, and corneal scar were more likely to have vision impairment, defined as Snellen visual acuity worse than 20/50. Results of our study highlight the need for ongoing vision care in EVD survivors.

In July 2023, cases of highly pathogenic avian influenza (HPAI) were reported at 2 shelters for stray cats in Seoul, South Korea. The cause of infection was suspected to be improperly sterilized raw food made from domestic duck meat, which was manufactured in South Korea. All viruses isolated from cats at the shelters and from the raw food belonged to HPAI A(H5N1) clade 2.3.4.4b. The gene constellation of all viruses was most similar to that of viruses isolated in Korea in November 2022. Of note, the viruses isolated from infected cats harbored mutations E627K or D701N in polymerase basic 2, which are indicative of adaptation to mammals. Postmortem examination revealed systemic pathologic lesions and the presence of widespread virus in different tissues. Thus, consumption of raw duck meat contaminated with HPAI virus likely caused systemic symptoms and death in cats, indicating the introduction of mammal-adapted mutations of the virus.

Circovirus human is a new viral species that includes the human circovirus (HCirV), which has been linked to hepatitis in immunocompromised persons. We investigated prevalence of HCirV infection in 278 patients with hepatitis and 184 asymptomatic persons using real-time PCR and sequencing assays. HCirV viremia and sequences were found in 8 (2.9%) hepatitis patients and no asymptomatic patients. Alternate causes of hepatitis (hepatitis E and cholangitis) were clearly identifiable in 2 HCirV-infected patients. HCirV could not be ruled out as a contributor to hepatitis in the remaining 6 patients, 4 of whom were immunocompromised. Persistent infections were documented in 3 patients, but only 1 had relapsing hepatitis. One HCirV patient displayed symptoms of an infectious mononucleosis-like syndrome. Isolates clustered with known HCirV strains from France and China. HCirV-derived virus-like particles bound to PLC/PRF/5 and Hep-G2 human hepatoma cells but not to lung epithelial cells, indicating hepatic tropism.

To explore hantavirus infection patterns in Latin America, we conducted molecular and serologic hantavirus investigations among 3,400 febrile patients from Peru during 2020–2021. Reverse transcription PCR indicated that a patient from Loreto, in the Peruvian Amazon, was positive for Rio Mamore hantavirus (serum, 3.8 × 10³ copies/mL). High genomic sequence identity of 87.0%–94.8% and phylogenetic common ancestry with a rodent-associated Rio Mamore hantavirus from Loreto in 1996 indicated endemicity. In 832 samples from Loreto, hantavirus incidence based on IgM ELISA of pooled Sin Nombre (SNV) and Andes virus (ANDV) nucleoproteins and immunofluorescence assay–based end-point titration using SNV/ANDV/Hantaan/Puumala/Saarema/Dobrava/Seoul hantaviruses was 0.5%. Across 3 ecologically distinct departments in Peru, SNV/ANDV IgG ELISA/IFA–based reactivity was 1.7%, suggesting circulation of antigenically distinct New World hantaviruses. Testing for arboviruses, nonendemic pathogens, and antigen-free ELISA corroborated nonspecific reactivity in 2 IgG and several IgM ELISA–positive serum samples. Hantavirus diagnostics and surveillance should be strengthened in Peru ad across Latin America.

We identified a novel mastadenovirus, herein referred to as colobus adenovirus (CoAdV), as the likely cause of fatal respiratory and enteric diseases in multiple black-and-white colobuses (Colobus guereza) imported into Thailand in 2022. Among 9 affected colobuses, 4 died. Viral antigen was abundant in respiratory and enteric tissues, where prominent lesions and clinical signs were observed. We successfully cultivated CoAdV in Vero cells and characterized the complete viral genome, which indicated the virus is genetically distinct from other simian adenoviruses. We also conducted a retrospective study of archival samples from 7 other unrelated colobuses that had respiratory distress or diarrhea and found similar viral strains in 4 of those colobuses. Although we could not determine the potential harm to humans or other nonhuman primates from current information, the zoonotic and spillover potential of this virus to other related hosts should not be neglected. Veterinarians should consider CoAdV when pneumonia is diagnosed in colobuses.

The epidemiologic effects of Zika virus (ZIKV) sexual transmission in virus-endemic countries remain unclear. We conducted a 2-level, linear mixed-effects logistic regression analysis by using a recently acquired population-based ZIKV and chikungunya virus (CHIKV) serologic dataset obtained from persons residing in Northeast Brazil (n = 2,070 participants). We adjusted mathematical models for housing type and age of participants; the models indicated a significantly higher likelihood of ZIKV seropositivity among persons engaged in a sexual relationship within the same household (odds ratio 1.25 [95% CI 1.00–1.55]; p = 0.047), regardless of their partner’s ZIKV serostatus, and among participants with a ZIKV-seropositive sex partner within the same household (odds ratio 1.54 [95% CI 1.18–2.01]; p = 0.002). CHIKV was also modeled as a control; no sex-associated effects were observed for CHIKV serology. Inclusion of ZIKV sexual transmission in prevention and control strategies is urgently needed, particularly in ZIKV-endemic regions.

Intensive disease surveillance in an endangered population of Ethiopian wolves provided evidence of concurrent outbreaks of rabies and canine distemper viruses in 2019, including co-infection in an individual animal. Disease surveillance and intensive monitoring of wolf packs in Ethiopia were essential in detecting the concurrent outbreaks and enabled accurate assessment of disease from both pathogens. The study highlights the risk posed to endangered populations that are susceptible to, or live in areas with, reservoir hosts for canine distemper and rabies viruses. Instances of concurrent distemper and rabies outbreaks appear unusual in the existing literature; modeling for one disease might underestimate the risk for extinction. Concurrent outbreaks may have a larger effect than single-disease outbreaks, even in a population that has partial vaccination coverage. Researchers studying wildlife populations from a conservation perspective should be aware that both diseases can strike at once where susceptible populations exist.

Blastomyces spp. fungi, the causal agent of blastomycosis, are common in North America but do occur in other areas of the world. The most prevalent pathogen in the genus is B. dermatitidis. Most B. dermatitidis isolates originate from North America, but there are sporadic reports of B. dermatitidis recovery from Africa and Asia. High-quality reports that incorporate genetic information about the fungus outside North America have been rare. Genome sequencing of 3 fungal isolates from patients in India with chronic respiratory diseases revealed that the isolates belong to a genetically differentiated lineage of B. dermatitidis. Because the patients had no history of traveling outside of Asia, blastomycosis was most likely autochthonously acquired, which suggests a local population of B. dermatitidis. Our results suggest the endemic range of B. dermatitidis is larger than previously thought, calling for a reassessment of the geographic range of different agents of endemic mycoses.

We analyzed clinical manifestations, antifungal susceptibility, and treatment outcomes of cutaneous sporotrichosis in Thailand during 2018–2022. The study included 49 patients whose mean age was 58.7 (SD 16.9) years; 65.3% were female and 34.7% male. A history of cat exposure was reported in 32 (65.3%) patients who had a significantly higher prevalence of upper extremity lesions than did those without cat contact (90.6% vs. 41.7%; adjusted odds ratio 18.9 [95% CI 3.2–92.9]). Among patients >60 years of age, lesions were more likely to be nonpustular than for patients <60 years of age (82.1% vs. 52.4%; p = 0.033). All 9 isolates tested for antifungal drug susceptibility exhibited an itraconazole MIC of <1 μg/mL. Oral itraconazole monotherapy was effective; the median time-to-cure was 180 days (interquartile range 141–240 days). Physicians should heighten their awareness of potential sporotrichosis causes, particularly when a history of animal contact exists.

Japanese encephalitis (JE) is preventable using the affordable, effective, and safe live attenuated SA 14-14-2 JE vaccine (CD-JEV). We used a Markov model to evaluate the cost-effectiveness of 1 dose of CD-JEV compared with no vaccination in 3 vaccination strategies in Bangladesh: subnational campaign and routine immunization, subnational campaign and national routine immunization, and national routine immunization alone. For input parameters, we gathered information from a cost-of-illness study, medical literature, government documents, and expert opinions. The base-case analysis estimated that a subnational campaign for children <15 years of age and routine immunization over 20 birth cohorts in Rajshahi, Rangpur, and Chattogram yielded (in 2021 US dollars) a cost of $82.2 million, $981/disability-adjusted life years averted, $9,964/case averted, and $49,819/death averted (societal perspective). We projected CD-JEV vaccination would be cost-effective across cost perspectives and vaccination strategies in Bangladesh, yielding an incremental cost-effectiveness ratio of approximately one third of per capita national gross domestic product.

Visceral leishmaniasis derived from Leishmania donovani is transmitted by sand flies (Phlebotomus argentipes) throughout the Indian subcontinent. Although considered anthroponotic, L. donovani infects other mammals susceptible to sand fly bites, including dogs. Aggressive strategies to reduce sand fly populations in India have led to flies seeking nonhuman hosts, so understanding the role of dogs in L. donovani transmission has become critical. Our study investigated L. donovani infection in dogs and the potential for such infections to be transmitted back to sand flies. We performed xenodiagnosis by using P. argentipes on dogs (n = 73) with quantitative PCR–detectible parasitemia in both endemic and outbreak villages. We found that 12% (9/73) of dogs were infectious to sand flies during winter and rainy seasons. Patients with visceral leishmaniasis remain primary sources of L. donovani transmission, but our findings suggest a possible link between canine infection and human exposure.

We report general acceptance (61.0%) of an mpox vaccine in the Democratic Republic of the Congo among 5,226 survey respondents. Healthcare workers and respondents in historic mpox-endemic regions had higher acceptance rates. These data highlight the need for increased community engagement and sensitization before widespread deployment of mpox vaccines.

Australia is a sink for low pathogenicity avian influenza viruses, with isolated circulation occurring on the continent. We report the incursion of a Eurasian low pathogenicity avian influenza H5 virus into Australia. This report benefits surveillance and diagnostic work because of the risk and current absence of highly pathogenic avian influenza A(H5N1).

We report a patient in North Carolina, USA, with Heartland virus infection whose diagnosis was complicated by previous Ehrlichia chaffeensis infection. We identified E. ewingii–infected and Bourbon virus–infected tick pools at the patient’s residence. Healthcare providers should consider testing for tickborne viruses if ehrlichiosis is suspected.

We found Mycobacterium leprae, the most common etiologic agent of Hansen disease or leprosy, in tissues from 9 (18.75%) of 48 nine-banded armadillos (Dasypus novemcinctus) collected across continental Ecuador. Finding evidence of a wildlife reservoir is the first step to recognizing leprosy zoonotic transmission pathway in Ecuador or elsewhere.

We investigated a blastomycosis cluster among humans and canines in a neighborhood in Wisconsin, United States. We conducted interviews and collected serum specimens for Blastomyces antibody testing by enzyme immunoassay. Although no definitive exposure was identified, evidence supports potential exposures from the riverbank, riverside trails or yards, or construction dust.

The first isolate of the emerging filovirus Lloviu virus (LLOV) was obtained in 2022. No animal disease models have been established. We assessed the pathogenic potential of LLOV in ferrets after intranasal, intramuscular, or aerosol exposure. The lack of disease development shows ferrets are not a disease model for LLOV.

Analysis of liver tissue from a Cape penguin that died with hepatitis at a zoo in Germany revealed Umatilla virus. Testing uncovered Umatilla virus RNA in samples from 2 other deceased Cape penguins at the zoo. Our results expand knowledge of the prevalence of this virus in bird species across Germany.

Testing of ducks in Tennessee, United States, before introduction of highly pathogenic influenza A(H5N1) virus demonstrated a high prevalence of antibodies to influenza A virus but very low prevalence of antibodies to H5 (25%) or H5 and N1 (13%) subtypes. Antibody prevalence increased after H5N1 introduction.

In August 2023, ehrlichiosis was confirmed in a patient in Italy with a Haemaphysalis punctata tick attached to his neck. Gene sequences of Ehrlichia canis from the tick and the patient were identical, indicating a potential risk for this uncommon infection for persons participating in outdoor activities.

The virus species Protoparvovirus carnivoran 1 encompasses pathogens that infect both domestic and wild carnivores, including feline panleukopenia virus. We identified and characterized feline panleukopenia virus strains in a Marsican brown bear (Ursus arctos marsicanus) and a crested porcupine (Hystrix cristata) in Italy, extending the known host range of this virus.

We report a patient with lobomycosis caused by Paracoccidioides loboi fungi in the Andes-Amazon region of Bolivia. We examined clinical, epidemiologic, and phylogenetic data and describe potential transmission/environmental aspects of infection. Continued surveillance and identification of lobomycosis cases in South America are crucial to prevent the spread of this disease.

Seroprevalence of Jamestown Canyon virus in free-ranging caribou in North America is high. We demonstrate serum antibodies and RNA of the virus in blood and tissues of experimentally exposed reindeer with no clinical illness and minimal histopathologic changes. Caribou and reindeer may play a role in emergence and dissemination of vectorborne zoonoses in Arctic regions.

We analyzed >4,000 pig samples from slaughterhouses in Cambodia and found higher influenza A seroprevalence (40.0%) and prevalence (1.5%) among pigs from commercial farms than smallholder farms (seroprevalence 8.9%; prevalence 0.6%). Multivariable analyses revealed evidence of transmission after leaving farms. Findings have implications for influenza risk and surveillance in emerging livestock systems.

Migratory birds carry ticks harboring various pathogens, including the zoonotic Yezo virus. In Hokkaido, Japan, we collected ticks from migratory birds during 2020–2021. Eight of 385 pools, comprising 2,534 ticks, tested positive for Yezo virus RNA, suggesting Yezo virus might be spread through the flyways of migratory birds.

The 2014 chikungunya outbreak in the Dominican Republic resulted in intense local transmission, with high postoutbreak seroprevalence. The resulting population immunity will likely minimize risk for another large outbreak through 2035, but changes in population behavior or environmental conditions or emergence of different virus strains could lead to increased transmission.

A febrile man in Italy who had traveled to Cuba in July 2024 was diagnosed with Oropouche fever. Reverse transcription PCR detected prolonged shedding of Oropouche virus RNA in whole blood, serum, urine, and semen. Sixteen days after symptom onset, replication-competent virus was detected in semen, suggesting risk for sexual transmission.

Records suggest Bacillus anthracis was used in biowarfare during World War II, but evidence remains limited. We isolated B. anthracis from soil at the remains of a World War II–era laboratory in China. Phenotypic and genomic analyses confirmed the finding, highlighting the value of microbial forensics in biothreat investigation.

We report 2 canine cases of carbapenemase-producing Pseudomonas aeruginosa within a United States veterinary hospital associated with a human outbreak linked to over-the-counter artificial tears. We investigated veterinary hospital transmission. Veterinary antimicrobial resistance surveillance and infection prevention and control enhancements are needed to reduce transmission of carbapenemase-producing organisms.

Chronic wasting disease (CWD) is an emerging disease in Europe. We report an increase in interspecies transmission capacity and zoonotic potential of a moose CWD isolate from Europe after passage in an ovine prion protein–expressing host. Those results indicated some CWD prions could acquire enhanced zoonotic properties following adaptation in an intermediate species.

We isolated Salmonella enterica serovar Senftenberg in raw wastewater from 2 Pennsylvania wastewater treatment facilities during June 2022. Whole genome sequencing revealed 4 isolates separated by <4 single nucleotide polymorphisms from S. enterica Senftenberg in a cluster from the 2022 nationwide outbreak linked to contaminated peanut butter.

Diphyllobothriasis is a human parasitic infection that is widespread in the Northern Hemisphere. Popular sport fish such as pike and perch are the source of human infection. We document the autochthonous origin of diphyllobothriasis in a popular tourist destination in Central Europe, which likely marks recent colonization of the parasite.

In a US survey of infectious disease specialists, 61 respondents reported seeing >1 Bartonella quintana infection during 2014–2024. Diagnostic challenges included limited healthcare provider awareness, inadequate testing, and inconsistent healthcare access among affected populations. Early recognition of B. quintana infections is needed to improve outcomes among affected populations.

International pet travel and commercial operations have increased animal disease importation risks, including for Leishmania infantum, a deadly parasite of humans and domestic dogs. Collaborating as an interdisciplinary working group, we developed an operational tool for veterinary and public health practitioners to assess and manage L. infantum risk in dogs imported to the United States. Overall risk varies by dog, human, and geographic factors but could be high without proper controls. We determined dog risk management strategies should include application of sand fly insecticides and repellents, sterilization, and treatment. US public health authorities can use a One Health approach to manage L. infantum importation risks via infected dogs.

The Ebola virus disease (EVD) outbreak of 2013–2016 was large, leaving in its wake an estimated 17,000 survivors in West Africa. Uveitis is one of the most common ophthalmic manifestations of EVD, but long-term follow-up in the at-risk population is lacking. We conducted a retrospective cross-sectional study of 521 EVD survivors from Sierra Leone who underwent comprehensive ophthalmic examination a median of 1,289 days, or ≈3.5 years, after discharge from Ebola treatment units. The most common ophthalmic findings were cataracts (117 eyes, 11.2%), uveitis (86 eyes, 8.3%), dry eyes (81 eyes, 7.8%), and chorioretinal scar (68 eyes, 6.5%). EVD survivors with cataracts, uveitis, optic neuropathy, and corneal scar were more likely to have vision impairment, defined as Snellen visual acuity worse than 20/50. Results of our study highlight the need for ongoing vision care in EVD survivors.

Congregate homeless shelters are disproportionately affected by infectious disease outbreaks. We describe enterovirus epidemiology across 23 adult and family shelters in King County, Washington, USA, during October 2019–May 2021, by using repeated cross-sectional respiratory illness and environmental surveillance and viral genome sequencing. Among 3,281 participants >3 months of age, we identified coxsackievirus A21 (CVA21) in 39 adult residents (3.0% [95% CI 1.9%–4.8%] detection) across 7 shelters during October 2019–February 2020. We identified enterovirus D68 (EV-D68) in 5 adult residents in 2 shelters during October–November 2019. Of 812 environmental samples, 1 was EV-D68–positive and 5 were CVA21–positive. Other enteroviruses detected among residents, but not in environmental samples, included coxsackievirus A6/A4 in 3 children. No enteroviruses were detected during April 2020–May 2021. Phylogenetically clustered CVA21 and EV-D68 cases occurred in some shelters. Some shelters also hosted multiple CVA21 lineages.

Mycobacterium abscessus infection is challenging to treat. Extrapulmonary M. abscessus infections (EP-MAB) are less common than pulmonary M. abscessus infections. To evaluate treatment regimens, we retrospectively analyzed consecutive microbiologically confirmed EP-MAB cases diagnosed in France during 2012–2020. We studied 45 patients with EP-MAB, including 14 bone and joint infections, 10 skin and soft tissue infections, and 8 lymph node infections. Most (62%) patients had no reported immunodeficiency. In 27 patients, EP-MAB followed healthcare-associated (44%) or environmental (16%) injuries. Of the 45 isolates, 25 were subspecies abscessus, 10 bolletii, and 9 massiliense; 1 was unidentified. Cure was achieved for 36 (80%) patients who received a median antimicrobial regimen of 6 months; 22 (55%) also underwent surgery. Four patients died, and 5 were unavailable for follow-up. EP-MAB predominantly affects immunocompetent patients after an injury; outcomes are favorable. We propose a >6-month regimen of antimicrobial therapy with consideration for surgery and regular patient reassessment.

Pasteurella spp. can cause fatal zoonotic infections in humans. We performed a multicenter study to investigate the prevalence and clinical features of Pasteurella infections in South Korea during 2018‒2022. We also conducted a collaborative systematic review and meta-analysis of the global burden of Pasteurella bacteremia. The study included 283 cases found an increasing trend in Pasteurella infections. Blood cultures were positive in 8/35 (22.9%) cases sampled, for overall bacteremia-associated rate of 2.8% (8/283). Aging was a significant risk factor for bacteremia (odds ratio 1.05 [95% CI 1.01–1.10]), according to multivariate analyses. For the meta-analysis, we included a total of 2,012 cases from 10 studies. The pooled prevalence of bacteremia was 12.4% (95% CI 7.3%–18.6%) and of mortality 8.4% (95% CI 2.7%–16.5%). Our findings reflect the need for greater understanding of the increase in Pasteurella infections and the global burden of Pasteurella bacteremia to determine appropriate case management.

We investigated differences in risk factors and preventive behaviors by age and sex among persons with reported Lyme disease in Ontario, Canada, during 2015–2022. Incidence rates peaked among children 5–9 and adults 50–79 years of age. Median age was higher for female than male case-patients (54 vs. 51 years). Male case-patients reported more activity in wooded and tall grass areas than did female case-patients; fewer male case-patients reported sharing living space with outdoor-exposed companion animals. As age increased, more case-patients reported activity in blacklegged tick habitats, exposure to ticks, and wearing adequate clothing, but fewer reported sharing living space with outdoor-exposed companion animals. Adoption of preventive behaviors was relatively low and did not differ by sex. Male case-patients, children 5–9 years of age and their parents or caregivers, and adults >59 years of age represent populations that would benefit from tailored public health messaging on Lyme disease prevention.

We conducted a prospective study of 159 cases of Streptococcus dysgalactiae subspecies equisimilis (SDSE) bacteremia in 157 patients at 2 hospitals in Finland during November 2015–November 2019. Cellulitis was associated with nonsevere disease (p = 0.008); necrotizing fasciitis was associated with severe disease (p = 0.004). Fifty percent of patients had >1 clinical characteristic associated with risk for death. The case-fatality rate was 6%, and 7% of patients were treated in an intensive care unit. Blood leukocyte counts on days 2 (p = 0.032) and 3 (p = 0.020) and C-reactive protein levels on days 3 (p = 0.030) and 4 (p = 0.009) after admission were predictors of severe disease. The Pitt bacteremia score was an accurate predictor of death. Using the Pitt bacteremia score, leukocyte counts, and CRP responses during initial treatment can improve treatment strategies and survival for patients with SDSE.

Evidence on mortality rates and causes of death associated with extrapulmonary nontuberculous mycobacteria (NTM) infection is limited. This nationwide register-based study in Denmark used diagnostic codes to match adult patients with extrapulmonary NTM infection 1:4 to controls. During 2000–2017, we identified 485 patients, who had significantly more comorbidities than controls. The 5-year mortality rate for patients was 26.8% (95% CI 23.1%–31.0%) and for controls, 10.9% (95% CI 9.6%–12.4%). The median age at death was 76 (interquartile range 63–85) years for patients and 84 (interquartile range 73–90) years for controls. The adjusted hazard rate of death for patients was 1.34 (95% CI 1.10–1.63; p = 0.004). Patients and controls mainly died of cardiovascular disease and solid malignant neoplasms. Hematologic malignancies and HIV were more frequently causes of death in patients. Mortality rates are substantial among patients with extrapulmonary NTM infection, predominantly caused by underlying conditions.

Human infections with Corynebacterium diphtheriae species complex (CdSC) bacteria were rare in French Guiana until 2016, when the number of cases diagnosed increased. We conducted an epidemiologic, multicenter, retrospective study of all human CdSC infections diagnosed in French Guiana during January 1, 2016–December 31, 2021. A total of 64 infectious episodes were observed in 60 patients; 61 infections were caused by C. diphtheriae and 3 by C. ulcerans. Estimated incidence increased from 0.7 cases/100,000 population in 2016 to 7.7 cases/100,000 population in 2021. The mean patient age was 30.4 (+23.7) years, and male-to-female ratio was 1.7:1 (38/22). Of the 61 C. diphtheriae isolates, 5 tested positive for the diphtheria toxin gene, and all results were negative by Elek test; 95% (61/64) of cases were cutaneous, including the C. ulcerans cases. The increase in reported human infections underscores the need to raise awareness among frontline healthcare practitioners to improve prevention.

Archaea represent a separate domain of life, next to bacteria and eukarya. As components of the human microbiome, archaea have been associated with various diseases, including periodontitis, endodontic infections, small intestinal bacterial overgrowth, and urogenital tract infections. Archaea are generally considered nonpathogenic; the reasons are speculative because of limited knowledge and gene annotation challenges. Nevertheless, archaeal syntrophic principles that shape global microbial networks aid both archaea and potentially pathogenic bacteria. Evaluating archaea interactions remains challenging, requiring clinical studies on inflammatory potential and the effects of archaeal metabolism. Establishing a culture collection is crucial for investigating archaea functions within the human microbiome, which could improve health outcomes in infectious diseases. We summarize potential reasons for archaeal nonpathogenicity, assess the association with infectious diseases in humans, and discuss the necessary experimental steps to enable mechanistic studies involving archaea.

Xenotransplantation, transplantation into humans of vascularized organs or viable cells from nonhuman species, is a potential solution to shortages of transplantable human organs. Among challenges to application of clinical xenotransplantation are unknown risks of transmission of animal microbes to immunosuppressed recipients or the community. Experience in allotransplantation and in preclinical models suggests that viral infections are the greatest concern. Worldwide, the distribution of swine pathogens is heterogeneous and cannot be fully controlled by international agricultural regulations. It is possible to screen source animals for potential human pathogens before procuring organs in a manner not possible within the time available for surveillance testing in allotransplantation. Infection control measures require microbiological assays for surveillance of source animals and xenograft recipients and research into zoonotic potential of porcine organisms. Available data suggest that infectious risks of xenotransplantation are manageable and that clinical trials can advance with appropriate protocols for microbiological monitoring of source animals and recipients.

We conducted surveillance for carbapenem-resistant Enterobacterales (CRE) during 2016–2020 at 10 US sites and extended-spectrum β-lactamase–producing Enterobacterales (ESBL-E) during 2019–2020 at 6 US sites. Among 159 CRE cases in children (median age 5 years), CRE was isolated from urine for 131 (82.4%) and blood from 20 (12.6%). Annual CRE incidence rate (cases/100,000 population) was 0.47–0.87. Among 207 ESBL-E cases in children (median age 6 years), ESBL-E was isolated from urine of 196 (94.7%) and blood of 8 (3.9%). Annual ESBL-E incidence rate was 26.5 in 2019 and 19.63 in 2020. CRE and ESBL-E rates were >2-fold higher among infants than other age groups. Most CRE and ESBL-E cases were healthcare-associated community-onset (68 [43.0%] for CRE vs. 40 [23.7%] for ESBL-E) or community-associated (43 [27.2%] for CRE vs. 109 [64.5%] for ESBL-E). Programs to detect, prevent, and treat multidrug-resistant infections must include pediatric populations (particularly the youngest) and outpatient settings.

Crimean-Congo hemorrhagic fever (CCHF) is a tickborne infection that can range from asymptomatic to fatal and has been described in >30 countries. Early identification and isolation of patients with suspected or confirmed CCHF and the use of appropriate prevention and control measures are essential for preventing human-to-human transmission. Here, we provide an overview of the epidemiology, clinical features, and prevention and control of CCHF. CCHF poses a continued public health threat given its wide geographic distribution, potential to spread to new regions, propensity for genetic variability, and potential for severe and fatal illness, in addition to the limited medical countermeasures for prophylaxis and treatment. A high index of suspicion, comprehensive travel and epidemiologic history, and clinical evaluation are essential for prompt diagnosis. Infection control measures can be effective in reducing the risk for transmission but require correct and consistent application.

Crimean-Congo hemorrhagic fever virus (CCHFV) is the most geographically widespread tickborne viral infection worldwide and has a fatality rate of up to 62%. Despite its widespread range and high fatality rate, no vaccines or treatments are currently approved by regulatory agencies in the United States or Europe. Supportive treatment remains the standard of care, but the use of antiviral medications developed for other viral infections have been considered. We reviewed published literature to summarize the main aspects of CCHFV infection in humans. We provide an overview of diagnostic testing and management and medical countermeasures, including investigational vaccines and limited therapeutics. CCHFV continues to pose a public health threat because of its wide geographic distribution, potential to spread to new regions, propensity for genetic variability, potential for severe and fatal illness, and limited medical countermeasures for prophylaxis and treatment. Clinicians should become familiar with available diagnostic and management tools for CCHFV infections in humans.

During October 2021–June 2023, a total of 392 cases of acute hepatitis of unknown etiology in children in the United States were reported to Centers for Disease Control and Prevention as part of national surveillance. We describe demographic and clinical characteristics, including potential involvement of adenovirus in development of acute hepatitis, of 8 fatally ill children who met reporting criteria. The children had diverse courses of illness. Two children were immunocompromised when initially brought for care. Four children tested positive for adenovirus in multiple specimen types, including 2 for whom typing was completed. One adenovirus-positive child had no known underlying conditions, supporting a potential relationship between adenovirus and acute hepatitis in previously healthy children. Our findings emphasize the importance of continued investigation to determine the mechanism of liver injury and appropriate treatment. Testing for adenovirus in similar cases could elucidate the role of the virus.

In 2022, concurrent outbreaks of hepatitis A, invasive meningococcal disease (IMD), and mpox were identified in Florida, USA, primarily among men who have sex with men. The hepatitis A outbreak (153 cases) was associated with hepatitis A virus genotype IA. The IMD outbreak (44 cases) was associated with Neisseria meningitidis serogroup C, sequence type 11, clonal complex 11. The mpox outbreak in Florida (2,845 cases) was part of a global epidemic. The hepatitis A and IMD outbreaks were concentrated in Central Florida and peaked during March–­June, whereas mpox cases were more heavily concentrated in South Florida and had peak incidence in August. HIV infection was more common (52%) among mpox cases than among hepatitis A (21%) or IMD (34%) cases. Where feasible, vaccination against hepatitis A, meningococcal disease, and mpox should be encouraged among at-risk groups and offered along with program services that target those groups.

Disseminated leishmaniasis (DL) is an emergent severe disease manifesting with multiple lesions. To determine the relationship between immune response and clinical and therapeutic outcomes, we studied 101 DL and 101 cutaneous leishmaniasis (CL) cases and determined cytokines and chemokines in supernatants of mononuclear cells stimulated with leishmania antigen. Patients were treated with meglumine antimoniate (20 mg/kg) for 20 days (CL) or 30 days (DL); 19 DL patients were instead treated with amphotericin B, miltefosine, or miltefosine and meglumine antimoniate. High levels of chemokine ligand 9 were associated with more severe DL. The cure rate for meglumine antimoniate was low for both DL (44%) and CL (60%), but healing time was longer in DL (p = 0.003). The lowest cure rate (22%) was found in DL patients with >100 lesions. However, meglumine antimoniate/miltefosine treatment cured all DL patients who received it; therefore, that combination should be considered as first choice therapy.

Streptococcus suis, a zoonotic bacterial pathogen circulated through swine, can cause severe infections in humans. Because human S. suis infections are not notifiable in most countries, incidence is underestimated. We aimed to increase insight into the molecular epidemiology of human S. suis infections in Europe. To procure data, we surveyed 7 reference laboratories and performed a systematic review of the scientific literature. We identified 236 cases of human S. suis infection from those sources and an additional 87 by scanning gray literature. We performed whole-genome sequencing to type 46 zoonotic S. suis isolates and combined them with 28 publicly available genomes in a core-genome phylogeny. Clonal complex (CC) 1 isolates accounted for 87% of typed human infections; CC20, CC25, CC87, and CC94 also caused infections. Emergence of diverse zoonotic clades and notable severity of illness in humans support classifying S. suis infection as a notifiable condition.

During January–August 2021, the Community Prevalence of SARS-CoV-2 Study used time/location sampling to recruit a cross-sectional, population-based cohort to estimate SARS-CoV-2 seroprevalence and nasal swab sample PCR positivity across 15 US communities. Survey-weighted estimates of SARS-CoV-2 infection and vaccine willingness among participants at each site were compared within demographic groups by using linear regression models with inverse variance weighting. Among 22,284 persons >2 months of age and older, median prevalence of infection (prior, active, or both) was 12.9% across sites and similar across age groups. Within each site, average prevalence of infection was 3 percentage points higher for Black than White persons and average vaccine willingness was 10 percentage points lower for Black than White persons and 7 percentage points lower for Black persons than for persons in other racial groups. The higher prevalence of SARS-CoV-2 infection among groups with lower vaccine willingness highlights the disparate effect of COVID-19 and its complications.

Invasive fusariosis can be life-threatening, especially in immunocompromised patients who require intensive care unit (ICU) admission. We conducted a multicenter retrospective study to describe clinical and biologic characteristics, patient outcomes, and factors associated with death and response to antifungal therapy. We identified 55 patients with invasive fusariosis from 16 ICUs in France during 2002­–­­2020. The mortality rate was high (56%). Fusariosis-related pneumonia occurred in 76% of patients, often leading to acute respiratory failure. Factors associated with death included elevated sequential organ failure assessment score at ICU admission or history of allogeneic hematopoietic stem cell transplantation or hematologic malignancies. Neither voriconazole treatment nor disseminated fusariosis were strongly associated with response to therapy. Invasive fusariosis can lead to multiorgan failure and is associated with high mortality rates in ICUs. Clinicians should closely monitor ICU patients with a history of hematologic malignancies or stem cell transplantation because of higher risk for death.

Using whole-genome sequencing, we characterized Escherichia coli strains causing early-onset sepsis (EOS) in 32 neonatal cases from a 2019–2021 prospective multicenter study in France and compared them to E. coli strains collected from vaginal swab specimens from women in third-trimester gestation. We observed no major differences in phylogenetic groups or virulence profiles between the 2 collections. However, sequence type (ST) analysis showed the presence of 6/32 (19%) ST1193 strains causing EOS, the same frequency as in the highly virulent clonal group ST95. Three ST1193 strains caused meningitis, and 3 harbored extended-spectrum β-lactamase. No ST1193 strains were isolated from vaginal swab specimens. Emerging ST1193 appears to be highly prevalent, virulent, and antimicrobial resistant in neonates. However, the physiopathology of EOS caused by ST1193 has not yet been elucidated. Clinicians should be aware of the possible presence of E. coli ST1193 in prenatal and neonatal contexts and provide appropriate monitoring and treatment.

We describe detection of the previously rarely reported gram-positive bacterium Auritidibacter ignavus in 3 cases of chronic ear infections in Germany. In all 3 cases, the patients had refractory otorrhea. Although their additional symptoms varied, all patients had an ear canal stenosis and A. ignavus detected in microbiologic swab specimens. A correct identification of A. ignavus in the clinical microbiology laboratory is hampered by the inability to identify it by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Also, the bacterium might easily be overlooked because of its morphologic similarity to bacterial species of the resident skin flora. We conclude that a high index of suspicion is warranted to identify A. ignavus and that it should be particularly considered in patients with chronic external otitis who do not respond clinically to quinolone ear drop therapy.