We identified 34 patients with Coxiella burnetii infection using PCR; 31 (86%) cases were diagnosed from cardiac specimens. Nearly half (15/31, 48%) of those cases were not reported to any channel of national disease surveillance, indicating substantial underreporting for diseases identified using molecular methods at noncommercial laboratories.

Human ehrlichiosis is a potentially fatal tickborne disease caused by 3 species: Ehrlichia chaffeensis, E. ewingii, and E. muris eauclairensis. In the United States, 234 confirmed cases of E. ewingii ehrlichiosis were reported to the Centers for Disease Control and Prevention through the National Notifiable Diseases Surveillance System during 2013-2021; average annual incidence was 0.08 cases/1 million population. E. ewingii ehrlichiosis was reported more commonly among older, White, non-Hispanic, and male patients. Incidence and case counts generally increased yearly, except for 2020 and 2021. The highest number of cases were reported from Missouri and Arkansas. We report the geographic expansion of E. ewingii ehrlichiosis and the continued public health challenge of clarifying clinical manifestations of this infection. Clinician education will be essential to implement molecular assays to properly diagnose E. ewingii infection in patients and gain a better understanding of the epidemiology of this emerging disease.

OBJECTIVE: Pet ownership among people experiencing homelessness (PEH) is common, but access to shelter, veterinary care, and flea-preventative products for PEH who own pets in the US is not well described. We sought to evaluate current knowledge of fleas and flea-borne diseases and characterize practices around pets and service animals among staff at homeless shelters and outreach organizations. METHODS: In-person surveys were administered to staff at homeless shelters and on outreach teams in 7 states from August 2022 to April 2023 to evaluate knowledge, attitudes, and practices and to assess homeless shelter/organizational characteristics. RESULTS: Surveys were administered to 333 staff members at 60 homeless shelters and among 29 outreach teams. Seventy-eight percent of homeless shelters allowed pets or service animals. Only 2% of homeless shelters and 7% of outreach teams provided veterinary care; 15% of homeless shelters and 7% of outreach teams provided flea preventatives. Nearly three-quarters of surveyed homeless shelter staff responded that no steps were taken to treat fleas at their shelters. CONCLUSIONS: Veterinary care and availability of flea-preventative products are limited in homeless shelter and outreach organizations serving people experiencing homelessness. CLINICAL RELEVANCE: Pets of PEH might be at an increased risk of flea infestation and flea-borne diseases because of limited access to veterinary care and preventatives. Improving knowledge and access to flea prevention, screening, and treatment are critical to ensure PEH and their pets can consistently access homeless shelters or outreach services, and to prevent flea-borne disease transmission.

BACKGROUND AND AIMS: Louse-borne Bartonella quintana infection and flea-borne murine typhus are two potentially serious vector-borne diseases that have led to periodic outbreaks among people experiencing homelessness in the United States. Little is known about louse- and flea-borne disease awareness and prevention among staff who provide services to the population. We surveyed staff in seven US states to identify gaps in knowledge and prevention practices for these diseases. METHODS AND RESULTS: Surveys were administered to 333 staff at 89 homeless shelters and outreach teams in California, Colorado, Georgia, Maryland, Minnesota, New York and Washington from August 2022 to April 2023. Most participants (>68%) agreed that body lice and fleas are a problem for people experiencing homelessness. About half were aware that diseases could be transmitted by these vectors; however, most could not accurately identify which diseases. Less than a quarter of staff could describe an appropriate protocol for managing body lice or fleas. Misconceptions included that clients must isolate or be denied services until they are medically cleared. CONCLUSIONS: Our findings reveal significant knowledge gaps among staff who provide services to people experiencing homelessness in the prevention and control of louse- and flea-borne diseases. This demonstrates an urgent need for staff training to both reduce disease and prevent unnecessary restrictions on services and housing.

Rocky Mountain spotted fever (RMSF) is a potentially fatal tickborne disease caused by the bacterium, Rickettsia rickettsii and transmitted primarily by the brown dog tick (Rhipicephalus sanguineus) in the southwestern United States and Mexico. RMSF can be rapidly fatal if not treated early with doxycycline, making healthcare worker awareness and education critical to reduce morbidity and mortality. During 2008-2019, Mexicali experienced a RMSF epidemic with 779 confirmed cases, and an 11-year case-fatality rate of 18% (N = 140). A cross-sectional study was conducted with 290 physicians and physicians-in-training across 12 medical facilities in Mexicali. They were asked to complete a 23-item questionnaire to assess knowledge, attitudes, and practices for clinical, epidemiologic, and preventive aspects of RMSF. Half of participants were female, the largest age group was aged 25 to 44 (47%), and median time in practice was 6 years (interquartile rate: 1-21.5). Less than half (48%) surveyed were confident where diagnostic testing could be performed, and two-thirds did not regularly order serology (67%) or molecular diagnostic (66%) tests for RMSF when a patient presented with fever. Sixty-four percent knew doxycycline as first-line treatment of children < 8 years with suspected RMSF. When comparing healthcare workers with < 6 years of experience to those with ≥ 6 years, more experience was associated with greater confidence in where to have diagnostic testing performed (prevalence odds ratio [prevalence odds ratios [pOR]] = 2.3; P = 0.004), and frequency of ordering laboratory tests (serology, pOR = 3.3; P = 0.002; polymerase chain reaction, pOR = 3.9; P = 0.001). Continued education, including information on diagnostic testing is key to reducing morbidity and mortality from RMSF.

Q fever is a zoonotic disease caused by the bacterium Coxiella burnetii and can manifest in an acute or chronic form. Many persons with acute Q fever are asymptomatic, but some develop a febrile illness, pneumonia or hepatitis. Chronic infections are rare and occur in less than 5% of persons exposed. Forms of chronic Q fever include endocarditis, infection of vascular grafts or aneurysms, osteomyelitis and osteoarthritis. Acute and chronic Q fever are nationally notifiable diseases, and presented here are the incidence, demographics and distribution of acute and chronic Q fever in the United States during 2008-2017. We summarized passive surveillance data from the Centers for Disease Control and Prevention's (CDC) National Notifiable Diseases Surveillance System (NNDSS) and supplemental case report forms (CRFs). Health departments reported 1,109 cases of acute Q fever and 272 chronic Q fever cases to NNDSS during this period. The 10-year average annual incidence for acute Q fever was 0.36 cases per million persons, and the average annual incidence for chronic Q fever was 0.09. Males accounted for nearly 75% of both acute and chronic Q fever cases. Average annual incidence was highest among persons aged 60-69 years for both acute and chronic Q fever (0.70 cases per million persons and 0.25, respectively). As reported through CRFs, many Q fever cases did not have a known exposure to C. burnetii; 60% (n = 380) of acute Q fever cases did not report exposure to animals in the 2 months before symptom onset. Almost 90% (n = 558) did not report exposure to unpasteurized milk. Only 40% (n = 247) of persons with reported Q fever were employed in high-risk occupations. Even though Q fever is a rare disease in the United States, incidence doubled from 2008 to 2017.

BACKGROUND: Monitoring of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody prevalence can complement case reporting to inform more accurate estimates of SARS-CoV-2 infection burden, but few studies have undertaken repeated sampling over time on a broad geographic scale. METHODS: We performed serologic testing on a convenience sample of residual sera obtained from persons of all ages, at ten sites in the United States from March 23 through August 14, 2020, from routine clinical testing at commercial laboratories. We age-sex-standardized our seroprevalence rates using census population projections and adjusted for laboratory assay performance. Confidence intervals were generated with a two-stage bootstrap. We used Bayesian modeling to test whether seroprevalence changes over time were statistically significant. RESULTS: Seroprevalence remained below 10% at all sites except New York and Florida, where it reached 23.2% and 13.3%, respectively. Statistically significant increases in seroprevalence followed peaks in reported cases in New York, South Florida, Utah, Missouri and Louisiana. In the absence of such peaks, some significant decreases were observed over time in New York, Missouri, Utah, and Western Washington. The estimated cumulative number of infections with detectable antibody response continued to exceed reported cases in all sites. CONCLUSIONS: Estimated seroprevalence was low in most sites, indicating that most people in the U.S. have not been infected with SARS-CoV-2 as of July 2020. The majority of infections are likely not reported. Decreases in seroprevalence may be related to changes in healthcare-seeking behavior, or evidence of waning of detectable anti-SARS CoV-2 antibody levels at the population level. Thus, seroprevalence estimates may underestimate the cumulative incidence of infection.

We compared severe acute respiratory syndrome-related coronavirus-2 seroprevalence estimated from commercial laboratory residual sera and a community household survey in metropolitan Atlanta during April-May 2020 and found these two estimates to be similar (4.94% versus 3.18%). Compared with more representative surveys, commercial sera can provide an approximate measure of seroprevalence.