Articles from Emerging Infectious Diseases

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.

Plague is a rare but potentially life-threatening fleaborne zoonotic disease caused by Yersinia pestis. Public health agencies in the United States use multiple concurrent epidemiologic and ecologic strategies to determine Y. pestis exposure sites. We reviewed 196 plague case files from 1991–2018 to describe effort and yield of implemented strategies. All files included an epidemiologic component, and 71% were followed up with environmental investigations. Environmental samples were collected for laboratory testing in 88% of investigations. The percentages of investigations yielding laboratory evidence of local transmission varied from 28% for testing live-trapped rodents to 50% for pet serology. We suggest that collection and laboratory testing of samples should be prioritized when epidemiologic investigations implicate potential exposure in an unusual setting, in areas where many people could be at risk of exposure to Y. pestis, or in situations where prevention activities extend beyond educational outreach and incur greater costs.

Enterovirus D68 (EV-D68) represents a continuing public health concern, given its association with severe respiratory illness and neurologic complications. In this study, we analyzed EV-D68 circulation and genetic evolution during 2014–2024 using data from 18 countries in Europe. Of 61,297 enterovirus-positive specimens, molecular detection and viral protein 1 sequencing identified 3,541 (6%) EV-D68 cases. A biennial circulation pattern was observed; detection rates ranged from 9% in 2014 to 0.9% in 2019. The pattern was disrupted in 2020 because of measures implemented in response to the COVID-19 pandemic, but then notable increases occurred in 2021 (14%), 2022 (10.7%), and 2024 (20.6%). Subgenogroups B3 (59.8%) and A2/D (28.0%) were predominant; A2/D reemerged as dominant in 2024. Mutation analyses revealed changes in antigenic regions. Our findings underscore the persistent adaptation and resurgence of EV-D68 after COVID-19. Continued genomic surveillance is essential to monitor transmission patterns caused by antigenic changes.

Coccidioidomycosis (Valley fever), caused by Coccidioides spp. fungi, is a reemerging, neglected fungal disease endemic to arid and semiarid regions of the Americas. Environmental detection remains challenging because of spatial heterogeneity, seasonal variability, low DNA abundance, PCR inhibitors, and lack of standardized methods. We conducted environmental surveillance in Baja California, Mexico, an understudied region near the US–Mexico border, by collecting 74 soil samples from active rodent burrows across 5 locations. We evaluated droplet digital PCR (ddPCR) for Coccidioides detection and compared ddPCR with nested PCR targeting the internal transcribed spacer 1 region. ddPCR demonstrated greater sensitivity, detecting Coccidioides spp. DNA at all sampling sites, whereas nested PCR detected Coccidioides spp. DNA from only 1 site. Although additional work is required to rigorously quantify sensitivity and specificity, ddPCR could help identify Coccidioides environmental hotspots, thus enabling public health interventions, such as warning communities of areas that pose higher risk for infection.

Aedes aegypti mosquitoes drive arboviral outbreaks in tropical regions. Zika virus (ZIKV), linked to congenital and neurologic complications, caused a major outbreak in Puerto Rico, USA, in 2016, infecting ≈26% of the population. Autocidal gravid ovitraps (AGOs), pesticide-free devices targeting gravid Ae. aegypti mosquitoes, have been shown to reduce transmission of another arbovirus, chikungunya. During March–May 2017, we conducted a household-based serosurvey in 4 demographically similar communities in southeastern Puerto Rico, 2 with long-term AGO deployment (≈85% coverage) and 2 without, to assess effects of AGOs on ZIKV transmission. Among 271 participants >5 years of age, ZIKV seroprevalence was much lower in intervention than nonintervention communities (9.6% vs. 20.0%). Protective effects were strongest among older adults, larger households (>4 persons), and persons spending more time at home. Although study design and measurement limitations could limit generalizability of results, our findings support AGOs as sustainable nonchemical tools for reducing ZIKV infections.

We conducted a retrospective genomic surveillance study of St. Louis encephalitis virus (SLEV) in Texas, USA, to determine the genotypes circulating in the region. By using a custom tiled-amplicon assay with Oxford Nanopore sequencing, we generated 63 genomes from SLEV-positive mosquito pools and viral isolates collected during 2009–2024. Phylogenomic analysis revealed temporal overlap of genotype II and III circulation, but with distinct geographic segregation. Genotype II was confined to Gulf Coast counties with sustained local transmission, whereas genotype III was only in north and west Texas, but with persistent circulation and repeated introductions. We identified the earliest known US genotype III sequences, although their phylogenetic placement leaves the entry point of genotype III into the United States unresolved. Our findings emphasize the need for clinical vigilance in West Texas, where SLEV and West Nile virus co-circulate, and suggest the Gulf Coast may be buffered against foreign genotype introduction.

Accurate confirmation of Ebola vaccination (ERVEBO) is essential for interpreting serologic data and assessing vaccine coverage during Ebola virus (EBOV) outbreaks. Current GP1,2-based assays cannot reliably distinguish vaccine-induced immunity from responses generated by natural infection. We developed a multiplex Luminex assay incorporating EBOV GP1,2, secreted glycoprotein (sGP), and a modified vesicular stomatitis virus nucleoprotein (VSV-P-N), a vector antigen encoded by ERVEBO but absent from wild-type EBOV. By using samples from US vaccinees and controls and a small comparison set from the Democratic Republic of the Congo, we found sGP and VSV-P-N demonstrated 100% sensitivity and >97.6% specificity for identifying vaccinees. In samples collected after a ring vaccination campaign in Guinea, combined sGP and VSV-P-N positivity confirmed vaccination in 94.8% of persons with written and 90.8% of persons with verbal confirmation of vaccination history. Our findings show that sGP and VSV-P-N provide a reliable signature of ERVEBO vaccination and support improved Ebola surveillance.

Crimean-Congo hemorrhagic fever virus (CCHFV) was first isolated in the Democratic Republic of the Congo (DRC) in 1956. To date, only 3 sporadic human cases have been reported in the DRC, and data on CCHFV infection in livestock, which are key players in transmission, are scant. We conducted a cross-sectional seroepidemiological study on archived human and animal serum samples collected from 25 provinces across the DRC. Samples were tested using an ELISA detecting CCHFV nucleoprotein-specific antibodies. The seroprevalence of CCHFV infection in humans was 4.4% (55/1,239) and in domestic ruminants was 28.9% (322/1,114). High seroprevalences tended to correlate with increased age, specific climate conditions (e.g., tropical monsoon) and vegetation (e.g., mountain savanna) types, and higher elevation (>600 m). Our findings suggest that CCHFV actively circulates in animals and sporadically transmits to humans in the DRC, highlighting the need for continued surveillance of CCHFV infection.

To evaluated artemisinin partial resistance (ART-R) in malaria in Burundi, during December 2023–June 2024, we studied 423 children <5 years of age with uncomplicated Plasmodium falciparum malaria in 8 health facilities in the northern part of the country. After artemether/lumefantrine treatment with only the first dose directly observed, 4.5% remained parasitemic on day 3. No pfkelch13 mutations, validated or candidate markers of ART-R, were detected. However, markers of antifolate and 4-aminoquinoline resistance were widespread: the dhfr triple mutant N51I/C59R/S108N was nearly fixed (92%), dhps double and triple mutants were common (41% and 47%), and pfcrt CVIET, associated with chloroquine and amodiaquine resistance, predominated (84%). Geographic differences occurred in day-3 positivity and haplotype frequencies. Although ART-R markers were absent, delayed parasite clearance and near fixation of multidrug-resistant haplotypes serve as a warning. Strengthened efficacy monitoring and regional molecular surveillance are urgently needed to prevent drug-resistant P. falciparum from becoming established in Burundi.

The COVID-19 pandemic coincided with rising secondary bloodstream infections (BSIs) from multidrug-resistant organisms, including Candida auris. To assess candidemia trends, we conducted a retrospective analysis of blood culture isolates from public and private laboratories in South Africa taken during January 2019–June 2022. We evaluated weekly aggregated Candida BSI counts and COVID-19 cases using segmented regression within an interrupted time-series framework. In total, 15,393 candidemia cases were identified, 70% from the private sector. C. parapsilosis accounted for 39% of cases, whereas C. auris represented 26%. The proportion of C. auris increased significantly from 17% in 2019 to 31% in 2021 (p<0.01). After the pandemic onset, Candida BSIs rose by 11 cases per week (p = 0.03), largely driven by C. auris (+5 cases/week; p<0.01); peaks coincided with COVID-19 waves. Those results highlight an accelerated shift toward C. auris in Candida BSIs and the urgent need for enhanced surveillance, diagnostics, and infection prevention.

Dengue is hyperendemic in Brazil and is underestimated by passive surveillance. To better understand dengue incidence, we conducted epidemiologic analyses among participants, 2–59 years of age, from the placebo arm of a phase 3 dengue vaccine trial. During 2016–2021, a total of 5,947 participants contributed to 22,028 person-years of follow-up. We identified and virologically confirmed dengue (VCD), Zika, and chikungunya infections. We observed VCD and chikungunya incidence heterogeneity by age, geographic location, and study year. Children 2–6 years of age experienced the highest VCD (2.33/100 person-years) and chikungunya (1.02/100 person-years) incidence. VCD peaked in 2019 (n = 148) whereas chikungunya peaked in 2017 (n = 51). VCD incidence rates from active surveillance were generally higher than those reported to the national passive surveillance system; expansion factor range was <1–9.5 by municipality. Active surveillance is critical to better understand and characterize dengue epidemiology.

Estimating the transmissibility of asymptomatic Mycobacterium tuberculosis infection can clarify its contribution to tuberculosis (TB) spread. We conducted a prospective cohort study in Lima, Peru, enrolling index TB patients and their household contacts (HHCs) and classifying patients by the presence of symptoms including cough, night sweats, weight loss, or fever. We followed HHCs with serial tuberculin skin testing and clinical evaluations. Among 4,296 child HHCs, adjusted estimates for baseline infection (prevalence ratio 0.62 [95% CI 0.37–1.03]), incident infection at 6 months (hazard ratio (aHR) 0.63 [95% CI 0.27–1.49]), and TB disease during 1 year of follow-up (aHR 0.74 [95% CI 0.35–1.56]) were all consistent with lower risk for infection and disease progression among HHCs of asymptomatic compared with symptomatic index patients. Although asymptomatic infections may be less transmissible than symptomatic infections, the high prevalence of asymptomatic patients in national surveys suggest that they may contribute substantially to transmission.

In January 2025, the Escherichia coli National Reference Center of France detected an outbreak of hemolytic uremic syndrome (HUS) in adults, caused by Shiga toxin–producing E. coli negative for locus of enterocyte effacement (LEE). The outbreak included 18 confirmed cases of E. coli infection, 5 probable or possible cases detected by in-house specific PCR, and 2 additional cases from Scotland and Belgium. Whole-genome sequencing identified the outbreak strain as O77 g:K92:H18, belonging to phylogroup D; the strain harbored the Shiga toxin 2 gene variant stx2d-073-C165-02 and a 134-kb plasmid with enterotoxin genes (estb-STb2 and eltAB). Epidemiologic investigation implicated raw-milk cheese as the contamination source. The strain represents a singular hybrid pathotype of Shiga toxin–producing and enterotoxigenic E. coli, expressing a K92 capsule with known cross-immunogenicity to Neisseria meningitidis group C, which could explain the absence of pediatric cases. Related strains have been identified in international databases since 2005, suggesting global emergence.

In Bangladesh, influenza A(H5N1) viruses are endemic in poultry. Processing infected chickens can aerosolize viruses, increasing the risk for human infections. We evaluated particulate matter (PM_2.5) mass concentration during slaughtering and defeathering methods used in live bird markets in Bangladesh to identify solutions to reduce aerosol exposure. We slaughtered 675 chickens using cones and barrels with 3 lid types and defeathered 45 chickens using a defeathering machine with 5 lid types. We interviewed 3 slaughterers to understand method preference. For slaughtering, barrels with a solid or star-cut lid reduced PM_2.5 mass concentrations by 65%–73% compared with uncovered barrels. For defeathering, machines fully covered by a solid lid or lid with a hole and pivot door reduced PM_2.5 mass concentrations by 50% compared with machines with no lid. Slaughterers preferred barrels covered with solid lids and defeathering machines covered with solid or hinged lids. Those methods might reduce aerosol exposure during poultry processing.

Chronic wasting disease (CWD) was identified in imported elk in South Korea in 2001 and has spread among cervids nationwide. The country’s surveillance and control policy culls cervids from any CWD-positive farms, and prevalence during 2020–2024 was <0.5%. Maintaining low prevalence in cervids will limit livestock, wildlife, and human CWD exposure.

During 2019–2021, the Republic of the Marshall Islands experienced a dengue outbreak involving 1,908 cases. Environmental sanitation helped stop transmission on Ebeye island, but transmission continued for >1 year on Majuro atoll. The Pacific region urgently needs to develop vector control capacity to address future dengue outbreaks.

Mpox, a reemerging zoonotic disease since 2022, primarily affects the skin; ocular involvement is rarely reported. We present a case of mpox-caused disciform keratitis treated with a combination of cidofovir and tecovirimat. The patient recovered without residual ocular sequelae, suggesting these drugs are an option to treat ocular mpox manifestations.

An elderly man, on dupilumab therapy for asthma and sinus polyposis, sought care for necrotic skin lesions. Biopsy revealed granulomatous vasculitis and he received immunosuppressive therapy but worsened. We diagnosed an Acanthamoeba infection that was treated with multidrug therapy including nitroxoline. Clinicians should be aware of this rare etiology for infectious vasculitis.

We characterized a recombinant mosaic coxsackievirus A9 strain responsible for severe inflammatory cardiomyopathy in a previously healthy child in northeastern France in 2024 by using whole-genome sequencing. This case highlights that enterovirus species other than coxsackievirus strain B3 can cause cardiomyopathy in otherwise healthy pediatric patients.

Whole-genome sequencing of Treponema pallidum subsp. endemicum strains from men who have sex with men in Japan revealed a genetically distinct lineage from other geographic regions circulating via sexual transmission. Strengthening global molecular epidemiologic surveillance is essential for clarifying epidemiologic trends, clinical characteristics, and transmission pathways of this subspecies.

We describe a community outbreak of Panton-Valentine leukocidin–positive methicillin-resistant Staphylococcus aureus (MRSA) during November 2023–June 2024 in the Netherlands. We identified a massage center as the source. Case-patients experienced skin infections and abscesses. This study highlights the importance of genomic surveillance of MRSA in distinguishing Panton-Valentine leukocidin–positive MRSA.

We report a case of Guillain-Barré syndrome with visual impairment after confirmed Oropouche virus infection during the 2024 outbreak in Ceará, Brazil. Whole-genome sequencing revealed infection by a novel reassortant viral lineage (OROVBR_2025_2024), raising concern about the neurovirulence of this emerging orthobunyavirus strain.

Molecular analyses of African swine fever (ASF) outbreaks in northern and central Vietnam during 2023–2024 revealed a rapid expansion (14.1%–42.2%) of recombinant ASF virus genotypes I and II. Increased prevalence and resistance to commercial ASF vaccines underscore the urgent need for better ASF control and an updated vaccine in Vietnam.

We assessed whether acute febrile illness surveillance could provide timely estimates of population immunity. In the Dominican Republic, antibody levels and inferred protection were similar between surveillance data and household survey serum samples, suggesting that surveillance platforms may offer a scalable approach to track population-level protection.

We conducted a cross-sectional serosurvey for Oropouche virus (OROV) among residents of Amazonas State, Brazil, during 2015–2016. We detected OROV neutralizing antibodies in 85/814 (10.4%) participants; seroprevalence was higher in Manaus (49/440 [11.1%]) than in Coari (36/374 [9.6%]). Those findings suggest OROV circulation in Amazonas State before 2015.

Using metagenomic sequencing, we identified a patient infected with Rickettsia lanei who was initially diagnosed with Rocky Mountain spotted fever (RMSF), a clinically similar disease caused by infection with R. rickettsii. Our investigation highlights the importance of clinical, epidemiologic, and laboratory partnerships to leverage the discovery of novel pathogens.

In Ebola outbreaks, families wait to bury their dead until a PCR whispers yes or no. Amid outbreaks of hemorrhagic fever in Senegal, laboratories raced clocks they could not command as loved ones stood by. This essay explores the ethics and emotion of that fragile interval between sample and answer.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Talaromycosis is a life-threatening fungal disease that primarily affects immunocompromised persons in Southeast Asia. We conducted a multicenter, case–control study recruiting participants with advanced HIV disease in Vietnam; 205 case-patients with culture-confirmed talaromycosis were matched to 405 control-patients by age, sex, and CD4 count. Occupational exposure to tropical plants (odds ratio [OR] 1.73 [95% CI 1.10–2.73]; p = 0.017) and to farmed animals (OR 2.07 [95% CI 1.20–3.55]; p = 0.009) were independent risk factors for talaromycosis. Talaromycosis risk was higher in participants from highland regions than in persons from lowland regions (p<0.05). Participants from lowland regions who had lived or traveled to highland regions had a higher risk for talaromycosis (OR 3.15 [95% CI 1.49–6.64]; p = 0.003). This study confirms the epidemiologic correlation between talaromycosis and soil exposure and demonstrates an epidemiologic link between talaromycosis and residence in or travel to highland regions of Vietnam.

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.

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.

Invasive aspergillosis (IA) caused by Aspergillus flavus remains poorly described. We retrospectively analyzed 54 cases of IA caused by A. flavus reported in France during 2012–2018. Among cases, underlying IA risk factors were malignancy, solid organ transplantation, and diabetes. Most (87%, 47/54) infections were localized, of which 33 were pleuropulmonary and 13 were ear-nose-throat (ENT) infection sites. Malignancy (70% [23/33]) and solid organ transplantation (21% [7/33]) were the main risk factors in localized pulmonary infections, and diabetes mellitus was associated with localized ENT involvement (61.5%, [8/13]). Fungal co-infections were frequent in pulmonary (36%, 12/33) but not ENT IA (0 cases). Antifungal monotherapy was prescribed in 45/50 (90%) cases, mainly voriconazole (67%, 30/45). All-cause 30-day case-fatality rates were 39.2% and 90-day rates were 47.1%, and rates varied according to risk factor, IA site, and fungal co-infections. Clinicians should remain vigilant for A. flavus and consider it in the differential diagnosis for IA.

Risk factors for developing bloodstream infections (BSIs) caused by Aerococcus bacteria remain insufficiently examined. In this nationwide case–control study in Sweden, 19 of 23 clinical microbiological laboratories identified patients who had aerococcal BSIs during 2012–2016. We compared each of those index patients with 4 controls matched for age, sex, and county of residence. Overall, 588 episodes of aerococcal BSI occurred over 39.6 million person-years, corresponding to an average incidence of 1.48/100,000 person-years (95% CI 1.37–1.60/100,000 person-years). Most infections developed in men >65 years of age. Aerococcal BSI was associated with neurologic (adjusted odds ratio 2.89 [95% CI 2.26–3.70]) and urologic (adjusted odds ratio 2.15 [95% CI 1.72—2.68]) conditions and previous hospitalization or infection treatment. Our findings support the previously observed predilection for aerococcal BSIs developing in elderly men with urinary tract disorders. Awareness of Aerococcus spp. in patients, especially elderly men, will be needed to manage invasive infections.