A multistate measles outbreak, predominantly affecting members of close-knit communities with low measles vaccination coverage in New Mexico, Oklahoma, and Texas began in January 2025. As of April 17, a total of 800 cases have been reported in the United States in 2025; 654 (82%) cases in New Mexico, Oklahoma, and Texas have been associated with the ongoing outbreak. These cases represent an approximately 180% increase over the 285 measles cases reported in the United States during all of 2024, and the second highest annual case count in the United States in 25 years. Overall, 771 (96%) patients have been unvaccinated or had unknown vaccination status (77% were unvaccinated, and 14% had unknown vaccination status when excluding 590 cases reported by Texas, which requires explicit consent by law [i.e., opt-in] to enroll in the Texas Immunization Registry), 85 (11%) patients have been hospitalized, and three patients have died. Among 48 (6%) internationally imported cases, 44 (92%) occurred among U.S. residents. Endemic measles was declared eliminated in the United States in 2000 as a direct result of high 2-dose childhood coverage with the measles, mumps, and rubella (MMR) vaccine. However, measles cases and outbreaks continue to occur when travelers with measles return to the United States while they are infectious; larger U.S. outbreaks typically follow importation into close-knit communities with low vaccination coverage. Nationally, risk for widespread measles transmission remains low because of high population-level immunity. To prepare for and prevent measles cases and outbreaks, public health departments should continue working with trusted community messengers on culturally competent community engagement, education, vaccination efforts, and other community infection prevention approaches (e.g., case isolation, contact monitoring, and post-exposure prophylaxis) and coordinating with health care facilities and schools. Increasing national and local MMR vaccination coverage is essential to preventing measles cases and outbreaks.

BACKGROUND: Despite high vaccine effectiveness, wild-type measles can occur in previously vaccinated persons. We compared the clinical presentation and disease severity of measles by vaccination status and age in the postelimination era in the United States. METHODS: We included U.S. measles cases reported from 2001 to 2022. Breakthrough measles was defined as cases with ≥1 documented dose of measles-containing vaccine, classic measles as the presence of rash, fever, and ≥1 symptoms (cough, coryza, or conjunctivitis), and severe disease as the presence of pneumonia, encephalitis, hospitalization, or death. Vaccinated cases with low- and high-avidity immunoglobulin G were classified as primary (PVF) and secondary (SVF) vaccine failures, respectively. RESULTS: Among 4056 confirmed measles cases, 2799 (69%) were unvaccinated, 475 (12%) were breakthrough infections, and 782 (19%) had unknown vaccination; 1526 (38%), 1174 (29%), and 1355 (33%) were aged <5, 5-19, and ≥20 years, respectively. We observed a general decline in classic presentation and severe disease with an increase in the number of doses and fewer complications among children aged 5-19 years compared to other age groups. Among 93 breakthrough cases with avidity results, 11 (12%) and 76 (82%) were classified as PVF and SVF, respectively, with a higher proportion of PVFs having a classic measles presentation and severe disease than SVFs. DISCUSSION: Breakthrough measles cases tended to have milder disease with less complications. A small proportion of breakthrough infections were due to PVF than SVF. It is critical to maintain high measles-mumps-rubella vaccination coverage in the United States to prevent serious measles illnesses.

On April 24, 2023, the American Samoa Department of Health (ASDoH) declared a public health emergency amid concern about a possible measles outbreak given low 2-dose vaccination coverage at the time. ASDoH had received two positive measles immunoglobulin (Ig) M test results after Flag Day festivities 1 week earlier from vaccinated children. ASDoH performed active case finding, took actions to mitigate transmission, and requested technical assistance from CDC. ASDoH implemented a vaccination campaign to improve suboptimal coverage. Confirmatory molecular testing of specimens from these initial persons under investigation (PUIs) was not possible, but subsequent testing of specimens from additional PUIs by Hawaii State Laboratories Division and CDC ruled out measles. In settings with low measles prevalence, measles antibody testing results have low positive predictive value and can lead to difficulties with interpreting results. Testing for additional pathogens revealed a variety of viruses known to cause common childhood viral exanthems. Both molecular and serologic testing should be performed for all suspected measles cases. To decrease the probability of false-positive IgM results, testing should be reserved for cases that meet the Council of State and Territorial Epidemiologists measles case definition, especially those in persons with no evidence of immunity and with a history of recent international travel. In addition, maintaining high measles vaccination coverage can prevent future outbreaks.

BACKGROUND: Data regarding ocular tuberculosis (OTB) in the United States have not been previously reported. We evaluated trends of OTB compared with other extrapulmonary TB (EPTB). METHODS: We estimated the proportion of all EPTB cases (with or without concurrent pulmonary involvement) with OTB reported to the National Tuberculosis Surveillance System during 1993-2019. We compared demographics and clinical characteristics of people with OTB and other EPTB during 2010-2019. P values were calculated by chi-square test for categorical variables and Kruskal-Wallis for continuous variables. RESULTS: During 1993-2019, 1766 OTB cases were reported, representing 1.6% of 109 834 all EPTB cases: 200 (0.5% of 37 167) during 1993-1999, 395 (1.0% of 41 715) during 2000-2009, and 1171 (3.8% of 30 952) during 2010-2019. In contrast to persons with other EPTB, persons with OTB were older (median, 48 vs 44 years; P < .01), more likely to be US-born (35% vs 28%; P < .01), more likely to have diabetes (17% vs 13%; P < .01), and less likely to have HIV (1% vs 8%; P < .01). OTB was less likely to be laboratory confirmed (5% vs 75%; P < .01), but patients were more likely to be tested by interferon gamma release assay (IGRA; 84% vs 56%; P < .01) and to be IGRA positive (96% vs 80%; P < .01). CONCLUSIONS: Reported OTB increased during 1993-2019 despite decreasing TB, including EPTB; the largest increase occurred during 2010-2019. OTB was rarely laboratory confirmed and was primarily diagnosed in conjunction with IGRA results. More research is needed to understand the epidemiology of OTB to inform clinical and diagnostic practices.

INTRODUCTION: Testing for immunity to measles, mumps, and rubella should include only IgG; IgM testing is appropriate only if acute illness is suspected. The appropriateness of measles, mumps, and rubella IgM testing was evaluated in a national administrative dataset. METHODS: Laboratory testing for measles, mumps, and rubella during 2019-2022 was analyzed in 2024 using HealthVerity administrative claims and laboratory data. IgG, IgM, and reverse-transcriptase polymerase chain reaction (RT-PCR) testing are described by year, demographics, and region. IgM testing was examined for appropriateness, defined as an IgM test combined with diagnostic codes indicative of acute illness. RESULTS: During 2019-2022, IgM testing represented a small proportion of serologic testing (measles: 3.3%, mumps: 2.4%, rubella: 2.1%) but appeared to be appropriately performed in only 15.4% of cases for measles, 32.8% of cases for mumps, and 10.2% of cases for rubella. IgM testing was more commonly performed for female patients, with the largest discrepancy seen for rubella (90.5% female vs 9.5% male). IgM for measles and mumps was more often performed appropriately for persons aged 0-19 years (37.6% and 60.1%) compared with persons aged 20-49 years (11.8% and 22.0%) and 50+ years (16.5% and 33.8%). CONCLUSIONS: The majority of IgM testing for measles, mumps, and rubella during this period appeared inappropriate. Clinicians and health systems could ensure that IgG testing alone is performed when evaluating for immunity through modifications to electronic medical records and commercial laboratories could ensure that providers are able to test for IgG alone when evaluating immunity.

Measles and rubella are vaccine-preventable viral diseases and can be prevented by safe, highly effective vaccination with measles- and rubella-containing vaccines. Given the myriad causes of febrile exanthems, laboratory surveillance for both measles and rubella is important to document the incidence of these diseases and to track the progress and maintenance of elimination in near- and post-elimination settings. Diagnostic challenges can hinder effective surveillance and classification challenges can hinder efforts to demonstrate achievement or maintenance of elimination. In this report, we review diagnostic and classification challenges for measles and rubella in near- and post-elimination settings.

BACKGROUND: People experiencing homelessness (PEH) are underrepresented in public health and clinical research. Study methods that can improve participation by this group are needed. METHODS: In late 2022, the Centers for Disease Control and Prevention conducted an mpox serological survey using venipuncture among PEH in San Francisco, California. Blood collection by a minimally invasive device was offered if venipuncture was not possible or preferred. Participants who had a successful blood draw using the device were asked about device acceptability. RESULTS: Of the 209 successful blood collections, 137 (66%) were among participants who underwent venipuncture and 72 (34%) were among participants who used the device. Use of the device increased overall blood collection participation by 53%. Participants reported high acceptability and preference for the device over venipuncture. CONCLUSIONS: Minimally invasive blood collection devices may increase participation and representation of PEH in serosurveys.

Measles, a highly contagious respiratory virus with the potential to cause severe complications, hospitalization, and death, was declared eliminated from the United States in 2000; however, with ongoing global transmission, infections in the United States still occur. On March 7, 2024, the Chicago Department of Public Health (CDPH) confirmed a case of measles in a male aged 1 year residing in a temporary shelter for migrants in Chicago. Given the congregate nature of the setting, high transmissibility of measles, and low measles vaccination coverage among shelter residents, measles virus had the potential to spread rapidly among approximately 2,100 presumed exposed shelter residents. CDPH immediately instituted outbreak investigation and response activities in collaboration with state and local health departments, health care facilities, city agencies, and shelters. On March 8, CDPH implemented active case-finding and coordinated a mass vaccination campaign at the affected shelter (shelter A), including vaccinating 882 residents and verifying previous vaccination for 784 residents over 3 days. These activities resulted in 93% measles vaccination coverage (defined as receipt of ≥1 recorded measles vaccine dose) by March 11. By May 13, a total of 57 confirmed measles cases associated with residing in or having contact with persons from shelter A had been reported. Most cases (41; 72%) were among persons who did not have documentation of measles vaccination and were considered unvaccinated. In addition, 16 cases of measles occurred among persons who had received ≥1 measles vaccine dose ≥21 days before first known exposure. This outbreak underscores the need to ensure high vaccination coverage among communities residing in congregate settings.

Measles is a highly infectious febrile rash illness and was declared eliminated in the United States in 2000. However, measles importations continue to occur, and U.S. measles elimination status was threatened in 2019 as the result of two prolonged outbreaks among undervaccinated communities in New York and New York City. To assess U.S. measles elimination status after the 2019 outbreaks and to provide context to understand more recent increases in measles cases, CDC analyzed epidemiologic and laboratory surveillance data and the performance of the U.S. measles surveillance system after these outbreaks. During January 1, 2020-March 28, 2024, CDC was notified of 338 confirmed measles cases; 97 (29%) of these cases occurred during the first quarter of 2024, representing a more than seventeenfold increase over the mean number of cases reported during the first quarter of 2020-2023. Among the 338 reported cases, the median patient age was 3 years (range = 0-64 years); 309 (91%) patients were unvaccinated or had unknown vaccination status, and 336 case investigations included information on ≥80% of critical surveillance indicators. During 2020-2023, the longest transmission chain lasted 63 days. As of the end of 2023, because of the absence of sustained measles virus transmission for 12 consecutive months in the presence of a well-performing surveillance system, U.S. measles elimination status was maintained. Risk for widespread U.S. measles transmission remains low because of high population immunity. However, because of the increase in cases during the first quarter of 2024, additional activities are needed to increase U.S. routine measles, mumps, and rubella vaccination coverage, especially among close-knit and undervaccinated communities. These activities include encouraging vaccination before international travel and rapidly investigating suspected measles cases.

Objectives. To examine impacts of racial and ethnic disaggregation on the characterization of tuberculosis (TB) epidemiology among American Indian and Alaska Native (AI/AN) persons in the United States. Methods. Using data reported to the National Tuberculosis Surveillance System during 2001 to 2020, we compared annual age-adjusted TB incidence and the frequency of TB risk factors among 3 AI/AN analytic groups: non-Hispanic AI/AN alone persons, multiracial/Hispanic AI/AN persons, and all AI/AN persons (aggregate of the first 2 groups). Results. During 2009 to 2020, annual TB incidence (cases per 100 000 persons) among non-Hispanic AI/AN alone persons (range = 3.87-8.56) was on average 1.9 times higher than among all AI/AN persons (range = 1.89-4.70). Compared with non-Hispanic AI/AN alone patients with TB, multiracial/Hispanic AI/AN patients were significantly more likely to be HIV positive (prevalence ratio [PR] = 2.05) and to have been diagnosed while a resident of a correctional facility (PR = 1.71), and significantly less likely to have experienced homelessness (PR = 0.53) or died during TB treatment (PR = 0.47). Conclusions. Racial and ethnic disaggregation revealed significant differences in TB epidemiology among AI/AN analytic groups. Exclusion of multiracial/Hispanic AI/AN persons from AI/AN analytic groups can substantively affect estimates of racial and ethnic health disparities. (Am J Public Health. 2024;114(2):226-236. https://doi.org/10.2105/AJPH.2023.307498).

In the United States, there is currently no system to track donated human tissue products to individual recipients. This posed a challenge during an investigation of a nationwide tuberculosis outbreak that occurred when bone allograft contaminated with Mycobacterium tuberculosis (Lot A) was implanted into 113 patients in 18 U.S. states, including two patients at one healthcare facility in Colorado. A third patient at the same facility developed spinal tuberculosis with an isolate genetically identical to the Lot A outbreak strain. However, healthcare records indicated this patient had received bone allograft from a different donor (Lot B). We investigated the source of this newly identified infection, including the possibilities of Lot B donor infection, product switch or contamination during manufacturing, product switch at the healthcare facility, person-to-person transmission, and laboratory error. Findings included gaps in tissue traceability at the healthcare facility, creating the possibility for a product switch at the point-of-care despite detailed tissue-tracking policies. Nationally, 6 (3.9%) of 155 Lot B units could not be traced to final disposition. This investigation highlights the critical need to improve tissue-tracking systems to ensure unbroken traceability, facilitating investigations of recipient adverse events and enabling timely public health responses to prevent morbidity and mortality.

Mpox has affected many communities in the United States (U.S.), including people experiencing homelessness (PEH). Mpox vaccination has been an important tool to disrupt transmission and protect communities at risk of infection. To better understand mpox vaccine knowledge and attitudes, we surveyed 273 PEH and people accessing homeless service sites in San Francisco. Among 64 participants previously offered mpox vaccination, 38 (59 %) had received the vaccine. Among 209 participants not previously offered mpox vaccination, 108 (52 %) reported they would receive the vaccine. Vaccine acceptance was higher among transgender female participants and among male participants who reported male sex partner preference (MSM). Half of participants who declined vaccination identified that perception of personal risk and vaccine education may increase their likelihood of receiving an mpox vaccine. Leveraging trusted information sources to provide risk communication and vaccine education may increase vaccine uptake among PEH.

A systematic approach to contact investigations has long been a cornerstone of interrupting transmission of tuberculosis (TB) in community settings. This paper describes the implementation of a systematic 10-step contact investigation within an acute care setting during a multistate outbreak of healthcare-associated TB. A systematic approach to contact investigations might have applicability to the prevention of other communicable infections within healthcare settings.

Monkeypox (mpox) is a disease caused by an Orthopoxvirus. The 2022 multinational outbreak, which began in May 2022, has spread primarily by close skin-to-skin contact, including through sexual contact. Persons experiencing homelessness have been disproportionately affected by severe mpox (1). However, mpox prevalence and transmission pathways among persons experiencing homelessness are not known, and persons experiencing homelessness have not been specifically recommended to receive mpox vaccine during the 2022 outbreak (2,3). During October 25-November 3, 2022, a CDC field team conducted an orthopoxvirus seroprevalence survey among persons accessing homeless services or staying in encampments, shelters, or permanent supportive housing in San Francisco, California that had noted at least one case of mpox or served populations at risk. During field team visits to 16 unique sites, 209 participants completed a 15-minute survey and provided a blood specimen. Among 80 participants aged <50 years who did not report smallpox or mpox vaccination or previous mpox infection, two (2.5%) had detectable antiorthopoxvirus immunoglobulin (Ig) G antibody. Among 73 participants who did not report mpox vaccination or previous mpox infection and who were tested for IgM, one (1.4%) had detectable antiorthopoxvirus IgM. Together, these results suggest that three possible undetected mpox infections occurred among a sample of persons experiencing homelessness, highlighting the need to ensure that community outreach and prevention interventions, such as vaccination, are accessible to this population.

A nationwide tuberculosis outbreak linked to a viable bone allograft product contaminated with Mycobacterium tuberculosis was identified in June 2021. Our subsequent investigation identified 73 healthcare personnel with new latent tuberculosis infection following exposure to the contaminated product, product recipients, surgical instruments, or medical waste.

We report 2 immunocompetent and otherwise healthy adults in the United States who had monkeypox and required hospitalization for viral myocarditis. Both patients were unvaccinated against orthopoxviruses. They had shortness of breath or chest pain and elevated cardiac biomarkers. No immediate complications were observed. They were discharged home after symptoms resolved.

Monkeypox virus, an orthopoxvirus sharing clinical features with smallpox virus, is endemic in several countries in Central and West Africa. The last reported outbreak in the United States, in 2003, was linked to contact with infected prairie dogs that had been housed or transported with African rodents imported from Ghana (1). Since May 2022, the World Health Organization (WHO) has reported a multinational outbreak of monkeypox centered in Europe and North America, with approximately 25,000 cases reported worldwide; the current outbreak is disproportionately affecting gay, bisexual, and other men who have sex with men (MSM) (2). Monkeypox was declared a public health emergency in the United States on August 4, 2022.(†) Available summary surveillance data from the European Union, England, and the United States indicate that among MSM patients with monkeypox for whom HIV status is known, 28%-51% have HIV infection (3-10). Treatment of monkeypox with tecovirimat as a first-line agent is available through CDC for compassionate use through an investigational drug protocol. No identified drug interactions would preclude coadministration of tecovirimat with antiretroviral therapy (ART) for HIV infection. Pre- and postexposure prophylaxis can be considered with JYNNEOS vaccine, if indicated. Although data are limited for monkeypox in patients with HIV, prompt diagnosis, treatment, and prevention might reduce the risk for adverse outcomes and limit monkeypox spread. Prevention and treatment considerations will be updated as more information becomes available.

BACKGROUND: Mycobacterium tuberculosis transmission through solid organ transplantation has been well described, but transmission through transplanted tissues is rare. We investigated a tuberculosis outbreak in the USA linked to a bone graft product containing live cells derived from a single deceased donor. METHODS: In this outbreak report, we describe the management and severity of the outbreak and identify opportunities to improve tissue transplant safety in the USA. During early June, 2021, the US Centers for Disease Control and Prevention (CDC) worked with state and local health departments and health-care facilities to locate and sequester unused units from the recalled lot and notify, evaluate, and treat all identified product recipients. Investigators from CDC and the US Food and Drug Administration (FDA) reviewed donor screening and tissue processing. Unused product units from the recalled and other donor lots were tested for the presence of M tuberculosis using real-time PCR (rt PCR) assays and culture. M tuberculosis isolates from unused product and recipients were compared using phylogenetic analysis. FINDINGS: The tissue donor (a man aged 80 years) had unrecognised risk factors, symptoms, and signs consistent with tuberculosis. Bone was procured from the deceased donor and processed into 154 units of bone allograft product containing live cells, which were distributed to 37 hospitals and ambulatory surgical centres in 20 US states between March 1 and April 2, 2021. From March 3 to June 1, 2021, 136 (88%) units were implanted into 113 recipients aged 24-87 years in 18 states (some individuals received multiple units). The remaining 18 units (12%) were located and sequestered. 87 (77%) of 113 identified product recipients had microbiological or imaging evidence of tuberculosis disease. Eight product recipients died 8-99 days after product implantation (three deaths were attributed to tuberculosis after recognition of the outbreak). All 105 living recipients started treatment for tuberculosis disease at a median of 69 days (IQR 56-81) after product implantation. M tuberculosis was detected in all eight sequestered unused units tested from the recalled donor lot, but not in lots from other donors. M tuberculosis isolates from unused product and recipients were more than 99·99% genetically identical. INTERPRETATION: Donor-derived transmission of M tuberculosis via bone allograft resulted in substantial morbidity and mortality. All prospective tissue and organ donors should be routinely assessed for tuberculosis risk factors and clinical findings. When these are present, laboratory testing for M tuberculosis should be strongly considered. FUNDING: None.

During 1993-2019, the incidence of tuberculosis (TB) in the United States decreased steadily; however, during the later years of that period the annual rate of decline slowed (1) until 2020 when a substantial decline (19.9%) was observed. This sharp decrease in TB incidence might have been related to multiple factors coinciding with the COVID-19 pandemic, including delayed or missed TB diagnoses or a true reduction in TB incidence related to pandemic mitigation efforts and changes in immigration and travel (2). During 2021, a total of 7,860 TB cases were provisionally reported to CDC's National Tuberculosis Surveillance System (NTSS) by the 50 U.S. states and the District of Columbia (DC). National incidence of reported TB (cases per 100,000 persons) rose 9.4% during 2021 (2.37) compared with that in 2020 (2.16) but remained 12.6% lower than the rate during 2019 (2.71).* During 2021, TB incidence increased among both U.S.-born and non-U.S.-born persons. The increased TB incidence observed during 2021 compared with 2020 might be partially explained by delayed diagnosis of cases in persons with symptom onset during 2020; however, the continued, substantial reduction from prepandemic levels raises concern for ongoing underdiagnosis. TB control and prevention services, including early diagnosis and complete treatment of TB and latent TB infection, should be maintained and TB awareness promoted to achieve elimination in the United States.