Southern Appalachia is a region where Lyme disease is emerging but not yet considered endemic. In response to local concerns about increased numbers of tickborne disease cases, researchers collected ticks monthly at 22 residential properties in the town of Biltmore Forest, North Carolina. During November 2024-August 2025, a total of 373 ticks were collected, 287 (76.9%) of which were blacklegged ticks (Ixodes scapularis). Among these, 19 of 48 adult Ix. scapularis (39.6%) tested positive for Borrelia burgdorferi sensu stricto, the bacterium that causes Lyme disease. Borrelia miyamotoi and Anaplasma phagocytophilum were also identified in collected Ix. scapularis ticks, suggesting an expansion of the geographic range of these ticks and pathogens. These findings illustrate the evolving epidemiology of tickborne infection risk and the need for enhanced tick surveillance in southern Appalachia.

Cannabis hyperemesis syndrome (CHS) is a condition characterized by cyclical nausea and vomiting and is associated with frequent cannabis use. Data from CDC's National Syndromic Surveillance Program were analyzed to examine trends in CHS-involved emergency department (ED) visits before and after implementation of a new, CHS-specific International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis code on October 1, 2025. Monthly CHS-involved ED visits per 10,000 all-cause visits were assessed overall and by demographic characteristics. During January 2023-May 2026, a total of 199,565 ED visits involved CHS. During January 2023-September 2025, the proportion of ED visits that involved CHS remained mostly steady. In the first month after implementation of the new diagnostic code, the proportion of CHS-involved ED visits increased from 3.35 per 10,000 ED visits in September 2025 (preimplementation) to 11.26 per 10,000 ED visits in October 2025 (postimplementation). During the first 8 months after implementation of the new code (October 2025-May 2026), average monthly proportions of CHS-involved ED visits were 3.7 times as high as the monthly average during January 2023-September 2025. Higher proportions of CHS-involved ED visits were observed among persons aged 15-24 years and females, with more pronounced impacts among some demographic groups after code implementation. The abrupt, sustained increase might partly reflect improved recognition and coding of CHS rather than a true rise in incidence. These findings highlight a likely underestimated impact of CHS, suggesting the need to strengthen education about the risks associated with frequent cannabis use, expand ongoing surveillance efforts, and improve clinical recognition of CHS through continuing medical education and implementation of routine cannabis use assessment in ED settings.

On May 14, 2025, a county-level Chinese Center for Disease Control and Prevention (China CDC) in southwestern China received a report of the sudden death of four employees of a small workshop for ceremonial papermaking, which was operating without required safety and environmental approvals. The first person who died was a woman who lost consciousness while cleaning a wastewater tank. During the next 20 minutes, three of the woman's family members, also employees, entered the tank to attempt to rescue her. All four persons, including the workshop operator's wife, the workshop operator's son, the workshop operator, and the workshop operator's daughter, died. The county China CDC launched an immediate investigation, and the Intermediate Chinese Field Epidemiology Training Program and provincial and city China CDC staff members conducted a joint, on-site investigation that included identification of cases, analysis of the gas composition, and interviews of residents of the town and physicians to identify the cause of the apparent toxic exposure. Analyses revealed that levels of the highly toxic gases hydrogen sulfide, hydrogen fluoride, and phosphine were several times higher than the maximum allowable concentrations. Clinical signs among the decedents were consistent with poisoning by these gases. Lack of personal protective equipment in a confined space and the presence of toxic gases likely led to the multiple exposures and delayed response by rescue services. Although working in confined spaces with toxic gases is a known exposure risk, these exposures continue to be reported in China and have included deaths in the papermaking industry. These deaths highlight the importance of effective regulations for papermaking workshops and administrative controls, improved supervision, and education for workers.

In the United States, arthropodborne viruses (arboviruses) are primarily transmitted by infected mosquitoes or ticks; rarely, they can be transmitted through blood transfusion or organ transplantation. Whereas a majority of arboviral infections are asymptomatic, symptomatic infections range from mild febrile illness to severe neuroinvasive disease. This report summarizes data for nationally notifiable domestic arboviral diseases with illness onset in 2024. Forty-eight states and the District of Columbia reported 1,955 arboviral disease cases, including 189 (10%) deaths. Although the number of West Nile virus (WNV) disease cases in 2024 was below the 10-year median (2,162), WNV caused most reported arboviral disease cases (1,808; 92%). Powassan virus disease was the second most commonly reported arboviral disease (60; 3%), increasing from a previous high of 49 cases in 2023. A majority of patients with arboviral disease were aged ≥60 years (1,133; 58%), were male (1,223; 63%), and had illness onset during July-September (1,603; 82%). However, La Crosse virus disease occurred almost exclusively among children aged <18 years (35 of 37 cases; median age = 8 years; interquartile interval = 5-10 years). Variations in annual demographic characteristics, disease incidence, distribution, and seasonal temporality of arboviral diseases highlight the importance of quality and -timely surveillance to increase awareness of disease risk, facilitate testing, and implement control measures. Clinicians should consider arboviral testing for patients with acute febrile or neurologic illness during periods when mosquitoes and ticks are active. Reducing arboviral disease morbidity and mortality relies on use of personal protective measures (e.g., insect repellent and protective clothing), implementing vector-control activities, and screening blood and organ donors for WNV.

Salmonella species bacterial infections are a leading cause of enteric illness and can be diagnosed using bacterial culture or culture-independent diagnostic tests (CIDTs). All culture-diagnosed cases are considered culture confirmed. After a positive CIDT, infection can be culture confirmed if reflex culture is attempted and yields an isolate. A culture-unconfirmed infection is a CIDT-diagnosed infection for which reflex culture was not attempted or failed to yield an isolate. Foodborne Diseases Active Surveillance Network data from 2006 through 2023 were analyzed to compare the epidemiologic and clinical characteristics of Salmonella infections after stratifying by diagnostic method (culture versus CIDT) and culture confirmation status (culture confirmed versus unconfirmed). To improve the precision and stability of temporal trend estimates, incidence trends during 2004-2024, as opposed to 2006-2023, were evaluated overall, by diagnostic method, and by confirmation status using regression. Although overall incidence remained stable from 2004 through 2024, the incidence of culture-diagnosed and -confirmed infections declined, and the incidence of CIDT-diagnosed and unconfirmed infections increased. Culture- and CIDT-diagnosed Salmonella infections were demographically similar but exhibited distinct clinical patterns, with CIDT diagnosis associated with milder and more sporadic illnesses, which suggests that these infections were historically underdiagnosed by culture-based diagnostics. The success of prevention efforts that reduce more severe, traditionally culture-detected Salmonella infections might be offset by the expanded detection of milder infections through CIDTs. The increases in detection of milder infections through CIDTs may offset the results of successes in prevention efforts in reduction in severe Salmonella infections. Understanding how diagnostic methods influence observed surveillance trends is therefore critical for evaluating and guiding future prevention efforts.

Rubella is the leading cause of vaccine-preventable birth defects. Rubella virus infection during pregnancy can result in miscarriage, fetal death, stillbirth, or a constellation of birth defects known as congenital rubella syndrome (CRS). Vaccination is the primary method for preventing rubella and CRS, and a single dose of rubella-containing vaccine (RCV) provides lifelong protection. In 2024, the World Health Organization recommended introduction of RCV in all countries. Achieving rubella elimination is a priority of the Immunization Agenda 2030. This report summarizes global progress toward elimination of rubella and CRS during 2012-2024. During this period, the number of countries that introduced RCV increased from 132 of 194 (68%) to 179 (92%), and global coverage with the first routinely scheduled dose of RCV rose from 39% to 73%. The number of reported rubella cases declined by 66%, from 94,277 in 2012 to 31,593 in 2024, with large outbreaks increasingly concentrated in fewer countries and geographic shifts observed as vaccine introductions advanced. Modeled estimates suggest that CRS cases declined by approximately 70% during the same period. Since 2012 when accelerated rubella control activities began, 117 of 194 (60%) countries have verified elimination of endemic rubella virus transmission. Despite this, in 2024, approximately 21 million infants aged 12-23 months lived in the 15 countries that had not introduced RCV. Although substantial progress has been made, achieving and sustaining rubella and CRS elimination will require RCV introduction in all the remaining countries and continued commitment from all countries to strengthen immunization and surveillance systems.

Disseminated gonococcal infection (DGI) is a rare but serious complication of Neisseria gonorrhoeae infection that can result in severe illness or death. In April 2024, the Alaska Section of Epidemiology (SOE) identified an increase in suspected DGI cases in Anchorage, Alaska, prompting enhanced surveillance. The state's gonorrhea surveillance system and electronic health records were used to review all likely and verified DGI cases reported to SOE during January 2023-December 2024. Thirty-five DGI cases were identified, accounting for 0.35% (eight of 2,289) of all gonorrhea cases in 2023 and 1.3% (27 of 2,079) in 2024. The median patient age was 36 years, 51% of patients were male, and 37% had a documented substance use disorder. Overall, 21 (60%) patients experienced septic arthritis, and three (9%) patients developed endocarditis; 28 (80%) patients lacked mucosal symptoms. No deaths were reported. Eighteen available isolates collected during 2020-2024, including 14 from cases reported during 2023 and 2024, underwent antimicrobial susceptibility testing and whole-genome sequencing. Laboratory analyses identified a cluster of highly related isolates with a novel multilocus sequence type (MLST-18036) and markers of increased virulence; however, no resistance to first-line therapy (ceftriaxone) was detected. Clinicians should maintain a high index of suspicion for DGI in patients at risk for gonococcal infection, even in the absence of mucosal symptoms. Prompt diagnosis and treatment, prompt case reporting, and robust partner services are critical to preventing transmission and reducing DGI morbidity.

In February 2026, two travel-associated cases of measles were reported to the Wisconsin Department of Health Services (WDHS). Public health investigations for each case included wastewater (sewage) surveillance for wild-type measles, which was first implemented by the WDHS Wastewater Monitoring Program in June 2025. The virus from one case, caused by measles genotype D8, was detected by a wastewater surveillance assay before the case was identified by local health authorities, leading to public health notifications and action. Measles virus from the second case, caused by measles genotype B3, was not detected by the assay. Additional analysis of the measles wastewater assay, which is among the most widely used assays in the United States, revealed that the assay was not able to detect an internationally circulating variant of the measles B3 genotype. Two alternative assays confirmed that measles virus was present and detectable in the wastewater. The assay developers designed and released a modified assay that incorporated an additional probe that could detect the B3 variant. These cases demonstrate the potential benefit of wastewater surveillance in detecting wild-type measles virus from a single case, while also highlighting the importance of regularly monitoring wastewater assays with respect to available genomic data. These activities should be supported by up-to-date libraries of publicly available whole-genome sequencing data.

The Eaton wildfire burned during January 7-31, 2025, displacing approximately 100,000 residents, destroying 9,419 structures, and resulting in the deaths of 19 residents of the greater Pasadena, California, area. An evacuation shelter opened on January 7. On January 13, the Pasadena Public Health Department (PPHD) received reports of acute gastrointestinal illness, COVID-19, and influenza cases among shelter residents. An outbreak response was initiated, which included enhanced surveillance and improved infection prevention and control (IPC) measures. On January 18, additional assistance was requested from the California Department of Public Health (CDPH). During January 7-February 16 shelter operations, enhanced surveillance implemented in response to the outbreak identified 104 cases of norovirus, 56 of COVID-19, 29 of influenza, and 30 of nonspecified respiratory illness among residents and staff members. Reported norovirus, COVID-19, and influenza cases decreased sharply after January 22. The last case of reported illness was a COVID-19 case on February 6. Rapid implementation of isolation and IPC protocols and interagency communication were temporally associated with declines in reported cases. This response highlights the importance of ongoing adherence to and coordination of IPC measures for outbreak mitigation to protect the health of residents and staff members in shelters established in response to public health emergencies or disasters.

Acute flaccid myelitis (AFM) is a rare but serious neurologic condition that causes paralysis and primarily affects children. Clinically and radiologically, AFM is indistinguishable from the acute flaccid paralysis of poliomyelitis caused by poliovirus. Nationwide surveillance for AFM has been conducted in the United States since 2014, when an increase in AFM was first recognized. Laboratory testing and epidemiologic and clinical data collected through surveillance suggest that enteroviruses, particularly enterovirus D68 (EV-D68), are a common cause of AFM. EV-D68 circulation was associated with biennial peaks in AFM cases in the United States in 2014, 2016, and 2018. This report provides an update to nationwide surveillance of confirmed AFM cases during January 2020-December 2025. During this period, the number of confirmed AFM cases reported to CDC remained low (17-48 cases per year) compared with 2014, 2016, and 2018 (120-238 cases per year). Despite ongoing seasonal enterovirus circulation, including increases in EV-D68-associated respiratory illnesses identified from sentinel surveillance sites in 2022, 2024, and 2025, concurrent increases in AFM cases in nationwide surveillance data were not observed; EV-D68 was detected in one AFM patient specimen received by CDC during this period. A majority (approximately 75%) of confirmed cases of AFM occurred in persons who were reported to be up to date with polio vaccination; approximately one half had stool specimens collected and tested. In 2022, a polio case in an unvaccinated person was identified by testing stool specimens collected through AFM surveillance. Clinicians should ensure that stool samples are collected from patients with acute onset of flaccid weakness or paralysis and report all cases to their local health department.

Legionellosis is a bacterial disease caused by inhalation or aspiration of Legionella bacteria; Legionnaires disease is a type of legionellosis characterized by illness with pneumonia. During November 2024, the U.S. Virgin Islands (USVI) Department of Health (VIDOH) was notified of two confirmed Legionnaires disease cases among travelers to two different hotels on St. Croix Island. VIDOH investigated to determine exposure sources and prevent additional cases. Two additional legionellosis cases were identified. The four patients with cases were aged 53-73 years; two patients were hospitalized and none died. At hotel A, L. pneumophila was detected in three of 21 (14%) environmental samples. VIDOH required hotel A to close one guest room, remediate, and retest. At hotel B, L. pneumophila was detected in 22 of 40 (55%) samples. VIDOH required hotel B to cease hotel operations until remediation and retesting were completed. L. pneumophila was isolated from shower samples at both hotels, in the cistern and cold water system at hotel A, and in cold and hot water systems at hotel B. The two USVI outbreaks underscore the importance of reporting legionellosis among returned travelers to facilitate local public health investigations and prevent additional cases. In addition, in tropical climates, cold water systems operate at temperatures favorable for Legionella growth (77°F-113°F [25°C-45°C]), highlighting the importance of effective water management programs and water system disinfection to prevent disease spread.