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Reports of mpox are rising in Africa where the disease is endemic and in new countries where the disease has not been previously seen. The 2022 global outbreak of clade II mpox and an ongoing outbreak of the more lethal clade I mpox highlight the pandemic potential for monkeypox virus. Waning population immunity after the cessation of routine immunization for smallpox plays a key role in the changing epidemiologic patterns of mpox. Sustained human-to-human transmission of mpox is occurring widely in the context of insufficient population immunity, fueling genetic mutations that affect the accuracy of some diagnostic tests and that could lead to changing virulence. Additional research should address complex challenges for control of mpox, including improved diagnostics and medical countermeasures. The availability of vaccines should be expanded not only for outbreak response but also for broader routine use for persons in mpox-endemic countries.

Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

Clade I monkeypox virus (MPXV), which can cause severe illness in more people than clade II MPXVs, is endemic in the Democratic Republic of the Congo (DRC), but the country has experienced an increase in suspected cases during 2023-2024. In light of the 2022 global outbreak of clade II mpox, the increase in suspected clade I cases in DRC raises concerns that the virus could spread to other countries and underscores the importance of coordinated, urgent global action to support DRC's efforts to contain the virus. To date, no cases of clade I mpox have been detected outside of countries in Central Africa where the virus is endemic. CDC and other partners are working to support DRC's response. In addition, CDC is enhancing U.S. preparedness by raising awareness, strengthening surveillance, expanding diagnostic testing capacity for clade I MPXV, ensuring appropriate specimen handling and waste management, emphasizing the importance of appropriate medical treatment, and communicating guidance on the recommended contact tracing, containment, behavior modification, and vaccination strategies., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Christopher K. Brown reports uncompensated participation on the Prevention, Preparedness, and Response Consortium Training Academy Advisory Board. No other potential conflicts of interest were disclosed.

Monkeypox (mpox) is a serious viral zoonosis endemic in west and central Africa. An unprecedented global outbreak was first detected in May 2022. CDC activated its emergency outbreak response on May 23, 2022, and the outbreak was declared a Public Health Emergency of International Concern on July 23, 2022, by the World Health Organization (WHO),* and a U.S. Public Health Emergency on August 4, 2022, by the U.S. Department of Health and Human Services. † A U.S. government response was initiated, and CDC coordinated activities with the White House, the U.S. Department of Health and Human Services, and many other federal, state, and local partners. CDC quickly adapted surveillance systems, diagnostic tests, vaccines, therapeutics, grants, and communication systems originally developed for U.S. smallpox preparedness and other infectious diseases to fit the unique needs of the outbreak. In 1 year, more than 30,000 U.S. mpox cases were reported, more than 140,000 specimens were tested, >1.2 million doses of vaccine were administered, and more than 6,900 patients were treated with tecovirimat, an antiviral medication with activity against orthopoxviruses such as Variola virus and Monkeypox virus. Non-Hispanic Black (Black) and Hispanic or Latino (Hispanic) persons represented 33% and 31% of mpox cases, respectively; 87% of 42 fatal cases occurred in Black persons. Sexual contact among gay, bisexual, and other men who have sex with men (MSM) was rapidly identified as the primary risk for infection, resulting in profound changes in our scientific understanding of mpox clinical presentation, pathogenesis, and transmission dynamics. This report provides an overview of the first year of the response to the U.S. mpox outbreak by CDC, reviews lessons learned to improve response and future readiness, and previews continued mpox response and prevention activities as local viral transmission continues in multiple U.S. jurisdictions (Figure)., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Christopher R. Braden reports membership on the Global Task Force for Cholera Control’s steering committee and membership on the National Academies of Science, Engineering, and Medicines Forum on Microbial Threats. No other potential conflicts of interest were disclosed.

On May 17, 2022, the Massachusetts Department of Health announced the first suspected case of monkeypox associated with the global outbreak in a U.S. resident. On May 23, 2022, CDC launched an emergency response (1,2). CDC's emergency response focused on surveillance, laboratory testing, medical countermeasures, and education. Medical countermeasures included rollout of a national JYNNEOS vaccination strategy, Food and Drug Administration (FDA) issuance of an emergency use authorization to allow for intradermal administration of JYNNEOS, and use of tecovirimat for patients with, or at risk for, severe monkeypox. During May 17-October 6, 2022, a total of 26,384 probable and confirmed* U.S. monkeypox cases were reported to CDC. Daily case counts peaked during mid-to-late August. Among 25,001 of 25,569 (98%) cases in adults with information on gender identity, † 23,683 (95%) occurred in cisgender men. Among 13,997 cisgender men with information on recent sexual or close intimate contact, § 10,440 (75%) reported male-to-male sexual contact (MMSC) ≤21 days preceding symptom onset. Among 21,211 (80%) cases in persons with information on race and ethnicity, ¶ 6,879 (32%), 6,628 (31%), and 6,330 (30%) occurred in non-Hispanic Black or African American (Black), Hispanic or Latino (Hispanic), and non-Hispanic White (White) persons, respectively. Among 5,017 (20%) cases in adults with information on HIV infection status, 2,876 (57%) had HIV infection. Prevention efforts, including vaccination, should be prioritized among persons at highest risk within groups most affected by the monkeypox outbreak, including gay, bisexual, and other men who have sex with men (MSM); transgender, nonbinary, and gender-diverse persons; racial and ethnic minority groups; and persons who are immunocompromised, including persons with advanced HIV infection or newly diagnosed HIV infection., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

Zoonotic diseases represent a heavy global burden, causing important economic losses, impacting animal health and production, and costing millions of human lives. The vaccination of animals and humans to prevent inter-species zoonotic disease transmission is an important intervention. However, efforts to develop and implement vaccine interventions to reduce zoonotic disease impacts are often limited to the veterinary and agricultural sectors and do not reflect the shared burden of disease. Multisectoral collaboration, including co-development opportunities for human and animal vaccines, expanding vaccine use to include animal reservoirs such as wildlife, and strategically using vaccines to interrupt complex transmission cycles is needed. Addressing zoonoses requires a multi-faceted One Health approach, wherein vaccinating people and animals plays a critical role.

During the response to the 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa, CDC addressed the disease on two fronts: in the epidemic epicenter of West Africa and at home in the United States. Different needs drove the demand for information in these two regions. The severity of the epidemic was reflected not only in lives lost but also in the amount of fear, misinformation, and stigma that it generated worldwide. CDC helped increase awareness, promoted actions to stop the spread of Ebola, and coordinated CDC communication efforts with multiple international and domestic partners. CDC, with input from partners, vastly increased the number of Ebola communication materials for groups with different needs, levels of health literacy, and cultural preferences. CDC deployed health communicators to West Africa to support ministries of health in developing and disseminating clear, science-based messages and promoting science-based behavioral interventions. Partnerships in West Africa with local radio, television, and cell phone businesses made possible the dissemination of messages appropriate for maximum effect. CDC and its partners communicated evolving science and risk in a culturally appropriate way to motivate persons to adapt their behavior and prevent infection with and spread of Ebola virus. Acknowledging what is and is not known is key to effective risk communication, and CDC worked with partners to integrate health promotion and behavioral and cultural knowledge into the response to increase awareness of the actual risk for Ebola and to promote protective actions and specific steps to stop its spread. The activities summarized in this report would not have been possible without collaboration with many U.S. and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).

Rocky Mountain spotted fever (RMSF) is an emerging public health issue on some American Indian reservations in Arizona. RMSF causes an acute febrile illness that, if untreated, can cause severe illness, permanent sequelae requiring lifelong medical support, and death. We describe costs associated with medical care, loss of productivity, and death among cases of RMSF on two American Indian reservations (estimated population 20,000) between 2002 and 2011. Acute medical costs totaled more than $1.3 million. This study further estimated $181,100 in acute productivity lost due to illness, and $11.6 million in lifetime productivity lost from premature death. Aggregate costs of RMSF cases in Arizona 2002-2011 amounted to $13.2 million. We believe this to be a significant underestimate of the cost of the epidemic, but it underlines the severity of the disease and need for a more comprehensive study., (© The American Society of Tropical Medicine and Hygiene.)

Background: Rocky Mountain spotted fever (RMSF) is a disease that now causes significant morbidity and mortality on several American Indian reservations in Arizona. Although the disease is treatable, reported RMSF case fatality rates from this region are high (7%) compared to the rest of the nation (<1%), suggesting a need to identify clinical points for intervention., Methods: The first 205 cases from this region were reviewed and fatal RMSF cases were compared to nonfatal cases to determine clinical risk factors for fatal outcome., Results: Doxycycline was initiated significantly later in fatal cases (median, day 7) than nonfatal cases (median, day 3), although both groups of case patients presented for care early (median, day 2). Multiple factors increased the risk of doxycycline delay and fatal outcome, such as early symptoms of nausea and diarrhea, history of alcoholism or chronic lung disease, and abnormal laboratory results such as elevated liver aminotransferases. Rash, history of tick bite, thrombocytopenia, and hyponatremia were often absent at initial presentation., Conclusions: Earlier treatment with doxycycline can decrease morbidity and mortality from RMSF in this region. Recognition of risk factors associated with doxycycline delay and fatal outcome, such as early gastrointestinal symptoms and a history of alcoholism or chronic lung disease, may be useful in guiding early treatment decisions. Healthcare providers should have a low threshold for initiating doxycycline whenever treating febrile or potentially septic patients from tribal lands in Arizona, even if an alternative diagnosis seems more likely and classic findings of RMSF are absent., (Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Background: Rocky Mountain spotted fever (RMSF) has emerged as a significant cause of morbidity and mortality since 2002 on tribal lands in Arizona. The explosive nature of this outbreak and the recognition of an unexpected tick vector, Rhipicephalus sanguineus, prompted an investigation to characterize RMSF in this unique setting and compare RMSF cases to similar illnesses., Methods: We compared medical records of 205 patients with RMSF and 175 with non-RMSF illnesses that prompted RMSF testing during 2002-2011 from 2 Indian reservations in Arizona., Results: RMSF cases in Arizona occurred year-round and peaked later (July-September) than RMSF cases reported from other US regions. Cases were younger (median age, 11 years) and reported fever and rash less frequently, compared to cases from other US regions. Fever was present in 81% of cases but not significantly different from that in patients with non-RMSF illnesses. Classic laboratory abnormalities such as low sodium and platelet counts had small and subtle differences between cases and patients with non-RMSF illnesses. Imaging studies reflected the variability and complexity of the illness but proved unhelpful in clarifying the early diagnosis., Conclusions: RMSF epidemiology in this region appears different than RMSF elsewhere in the United States. No specific pattern of signs, symptoms, or laboratory findings occurred with enough frequency to consistently differentiate RMSF from other illnesses. Due to the nonspecific and variable nature of RMSF presentations, clinicians in this region should aggressively treat febrile illnesses and sepsis with doxycycline for suspected RMSF., (Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Objective: To evaluate whether cosmetically relevant dental effects occurred among children who had received doxycycline for treatment of suspected Rocky Mountain spotted fever (RMSF)., Study Design: Children who lived on an American Indian reservation with high incidence of RMSF were classified as exposed or unexposed to doxycycline, based on medical and pharmacy record abstraction. Licensed, trained dentists examined each child's teeth and evaluated visible staining patterns and enamel hypoplasia. Objective tooth color was evaluated with a spectrophotometer., Results: Fifty-eight children who received an average of 1.8 courses of doxycycline before 8 years of age and who now had exposed permanent teeth erupted were compared with 213 children who had never received doxycycline. No tetracycline-like staining was observed in any of the exposed children's teeth (0/58, 95% CI 0%-5%), and no significant difference in tooth shade (P=.20) or hypoplasia (P=1.0) was found between the 2 groups., Conclusions: This study failed to demonstrate dental staining, enamel hypoplasia, or tooth color differences among children who received short-term courses of doxycycline at <8 years of age. Healthcare provider confidence in use of doxycycline for suspected RMSF in children may be improved by modifying the drug's label., (Published by Elsevier Inc.)

Two national surveillance systems capturing reports of fatal Q fever were compared with obtained estimates of Q fever underreporting in the United States using capture-recapture methods. During 2000-2011, a total of 33 unique fatal Q fever cases were reported through case report forms submitted to the Centers for Disease Control and Prevention and through U.S. death certificate data. A single case matched between both data sets, yielding an estimated 129 fatal cases (95% confidence interval [CI] = 62-1,250) during 2000-2011. Fatal cases of Q fever were underreported through case report forms by an estimated factor of 14 and through death certificates by an estimated factor of 5.2., (© The American Society of Tropical Medicine and Hygiene.)

Q fever is a worldwide zoonosis historically associated with exposure to infected livestock. This study summarizes cases of Q fever, a notifiable disease in the United States, reported to the Centers for Disease Control and Prevention through two national surveillance systems with onset during 2000-2012. The overall incidence rate during this time was 0.38 cases per million persons per year. The reported case fatality rate was 2.0%, and the reported hospitalization rate was 62%. Most cases (61%) did not report exposure to cattle, goats, or sheep, suggesting that clinicians should consider Q fever even in the absence of livestock exposure. The prevalence of drinking raw milk among reported cases of Q fever (8.4%) was more than twice the national prevalence for the practice. Passive surveillance systems for Q fever are likely impacted by underreporting and underdiagnosis because of the nonspecific presentation of Q fever., (© The American Society of Tropical Medicine and Hygiene.)

Rocky Mountain spotted fever (RMSF) transmitted by the brown dog tick (Rhipicephalus sanguineus sensu lato) has emerged as a significant public health risk on American Indian reservations in eastern Arizona. During 2003-2012, more than 250 RMSF cases and 19 deaths were documented among Arizona's American Indian population. The high case fatality rate makes community-level interventions aimed at rapid and sustained reduction of ticks urgent. Beginning in 2012, a two year pilot integrated tick prevention campaign called the RMSF Rodeo was launched in a ∼ 600-home tribal community with high rates of RMSF. During year one, long-acting tick collars were placed on all dogs in the community, environmental acaricides were applied to yards monthly, and animal care practices such as spay and neuter and proper tethering procedures were encouraged. Tick levels, indicated by visible inspection of dogs, tick traps and homeowner reports were used to monitor tick presence and evaluate the efficacy of interventions throughout the project. By the end of year one, <1% of dogs in the RMSF Rodeo community had visible tick infestations five months after the project was started, compared to 64% of dogs in Non-Rodeo communities, and environmental tick levels were reduced below detectable levels. The second year of the project focused on use of the long-acting collar alone and achieved sustained tick control with fewer than 3% of dogs in the RMSF Rodeo community with visible tick infestations by the end of the second year. Homeowner reports of tick activity in the domestic and peridomestic setting showed similar decreases in tick activity compared to the non-project communities. Expansion of this successful project to other areas with Rhipicephalus-transmitted RMSF has the potential to reduce brown dog tick infestations and save human lives.

Rocky Mountain spotted fever, a tick-borne disease caused by Rickettsia rickettsii, is challenging to diagnose and rapidly fatal if not treated. We describe a decedent who was co-infected with group A β-hemolytic streptococcus and R. rickettsii. Fatal cases of Rocky Mountain spotted fever may be underreported because they present as difficult to diagnose co-infections., (© The American Society of Tropical Medicine and Hygiene.)

Among 13 suspected Rocky Mountain spotted fever (RMSF) cases identified through an enhanced surveillance program in Tennessee, antibodies to Rickettsia rickettsii were detected in 10 (77%) patients using a standard indirect immunofluorescent antibody (IFA) assay. Immunoglobulin M (IgM) antibodies were observed for 6 of 13 patients (46%) without a corresponding development of IgG, and for 3 of 10 patients (30%) at least 1 year post-onset. However, recent infection with a spotted fever group rickettsiae could not be confirmed for any patient, based on a lack of rising antibody titers in properly timed acute and convalescent serologic specimens, and negative findings by polymerase chain reaction testing. Case definitions used in national surveillance programs lack specificity and may capture cases that do not represent current rickettsial infections. Use of IgM antibodies should be reconsidered as a basis for diagnosis and public health reporting of RMSF and other spotted fever group rickettsiae in the United States., (© The American Society of Tropical Medicine and Hygiene.)

Among 2012 Docstyle survey respondents, 80% identified doxycycline as the appropriate treatment for Rocky Mountain spotted fever in patients ≥ 8 years old, but only 35% correctly chose doxycycline in patients <8 years old. These findings raise concerns about the higher pediatric case-fatality rate of Rocky Mountain spotted fever observed nationally. Targeted education efforts are needed., (Crown Copyright © 2014. Published by Mosby, Inc. All rights reserved.)

Objective: To examine dog bites among American Indian (AI) and Alaska Native (AN) children visiting Indian Health Service and tribal health facilities., Study Design: We retrospectively analyzed hospitalizations and outpatient visits with a diagnosis of dog bite between 2001 and 2008 in AI/AN children aged <20 years. Rates of dog bite hospitalizations and outpatient visits were estimated by age group, sex, region, and number and location of open wounds using Indian Health Service data. Analyses of hospitalizations for the general US population aged<20 years used the Nationwide Inpatient Sample., Results: The average annual dog bite hospitalization rate was higher among AI/AN children in Alaska (6.1/100,000 population) and the Southwest region (5.3/100,000) compared with the general US child population (3.1/100,000; 95% CI, 2.9-3.3/100,000). The average annual outpatient visit rate in AI/AN children was highest in the Alaska (596.4/100,000), Southwest (540.0/100,000), and Northern Plains West (537.6/100,000) regions. The hospitalization rate was highest in both AI/AN and US males aged<5 years, and outpatient visit rates were highest in AI/AN males aged 5-9 years. Open wounds diagnoses were most commonly seen on the head, neck, and face in hospitalized children (45.5% of open wounds in AI/AN children, 59.3% in US children; SE, 1.0%) and on the leg in AI/AN outpatients (35.6%)., Conclusion: Dog bites represent a significant public health threat in AI/AN children in the Alaska, the Southwest, and Northern Plains West regions of the US. Enhanced animal control and education efforts should reduce dog bite injuries and associated problems with pets and stray dogs, such as emerging infectious diseases., (Published by Mosby, Inc.)

Ehrlichiosis is a tick-borne disease that ranges in severity from asymptomatic infection to fatal sepsis. Ehrlichiosis acquired from transfusion of blood products has not been documented in the literature to date. A case of Ehrlichia ewingii infection likely transmitted by transfusion of leukoreduced platelets is described, and public health implications are discussed.

Q fever, a zoonotic disease caused by the bacterium Coxiella burnetii, can cause acute or chronic illness in humans. Transmission occurs primarily through inhalation of aerosols from contaminated soil or animal waste. No licensed vaccine is available in the United States. Because many human infections result in nonspecific or benign constitutional symptoms, establishing a diagnosis of Q fever often is challenging for clinicians. This report provides the first national recommendations issued by CDC for Q fever recognition, clinical and laboratory diagnosis, treatment, management, and reporting for health-care personnel and public health professionals. The guidelines address treatment of acute and chronic phases of Q fever illness in children, adults, and pregnant women, as well as management of occupational exposures. These recommendations will be reviewed approximately every 5 years and updated to include new published evidence.

Several spotted fever group rickettsiae (SFGR) previously believed to be nonpathogenic are speculated to contribute to infections commonly misdiagnosed as Rocky Mountain spotted fever (RMSF) in the United States, but confirmation is difficult in cases with mild or absent systemic symptoms. We report an afebrile rash illness occurring in a patient 4 days after being bitten by a Rickettsia montanensis-positive Dermacentor variabilis tick. The patient's serological profile was consistent with confirmed SFGR infection.

Ehrlichiosis and anaplasmosis infections among American Indians (AIs) have never been specifically examined, despite high rates of other tick-borne rickettsial diseases among AIs. The epidemiology of ehrlichiosis and anaplasmosis among AIs was analyzed using the National Electronic Telecommunications System for Surveillance (NETSS), Case Report Forms (CRFs), and Indian Health Service (IHS) inpatient and outpatient visits. The 2000-2007 average annual ehrlichiosis and anaplasmosis incidence among AIs reported to NETSS was almost 4-fold lower (4.0/1,000,000) than that using IHS data (14.9). American Indian cases reported from CRFs had a higher proportion of hospitalization (44%) compared with IHS (10%). American Indian incidence of ehrlichiosis and anaplasmosis was higher and showed a different age and geographical distribution than other races. These results highlight the need to improve collaboration between the ehrlichiosis and anaplasmosis surveillance systems for AIs so as to develop interventions that target the unique epidemiology and mitigate the burden of disease among this high-risk population.

Death from Rocky Mountain spotted fever (RMSF) is preventable with prompt, appropriate treatment. Data from two independent sources were analyzed to estimate the burden of fatal RMSF and identify risk factors for fatal RMSF in the United States during 1999-2007. Despite increased reporting of RMSF cases to the Centers for Disease Control and Prevention, no significant changes in the estimated number of annual fatal RMSF cases were found. American Indians were at higher risk of fatal RMSF relative to whites (relative risk [RR] = 3.9), and children less than 10 years of age (RR=5.1) [corrected] and adults ≥ 70 years of age (RR = 3.0) were also at increased risk relative to other ages. Persons with cases of RMSF with an immunosuppressive condition were at increased risk of death (RR = 4.4). Delaying treatment of RMSF was also associated with increased deaths. These results may indicate a gap between recommendations and practice.

American Indians are at greater risk for Rocky Mountain spotted fever (RMSF) than the general U.S. population. The epidemiology of RMSF among American Indians was examined by using Indian Health Service inpatient and outpatient records with an RMSF International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis. For 2001-2008, 958 American Indian patients with clinical diagnoses of RMSF were reported. The average annual RMSF incidence was 94.6 per 1,000,000 persons, with a significant increasing incidence trend from 24.2 in 2001 to 139.4 in 2008 (P = 0.006). Most (89%) RMSF hospital visits occurred in the Southern Plains and Southwest regions, where the average annual incidence rates were 277.2 and 49.4, respectively. Only the Southwest region had a significant increasing incidence trend (P = 0.005), likely linked to the emergence of brown dog ticks as an RMSF vector in eastern Arizona. It is important to continue monitoring RMSF infection to inform public health interventions that target RMSF reduction in high-risk populations.

US surveillance programs for Rocky Mountain spotted fever (RMSF), ehrlichiosis, and anaplasmosis collect demographic data on patients, including race and ethnicity. Reporting of these diseases among race groups is not uniform across the United States. Because a laboratory confirmation is required to meet the national surveillance case definition, reporting may be influenced by a patient's access to healthcare. Determining the association between race and ethnicity with incidence of rickettsial infections requires targeted, active surveillance.

Background: Ehrlichiosis is a clinically important, emerging zoonosis. Only Ehrlichia chaffeensis and E. ewingii have been thought to cause ehrlichiosis in humans in the United States. Patients with suspected ehrlichiosis routinely undergo testing to ensure proper diagnosis and to ascertain the cause., Methods: We used molecular methods, culturing, and serologic testing to diagnose and ascertain the cause of cases of ehrlichiosis., Results: On testing, four cases of ehrlichiosis in Minnesota or Wisconsin were found not to be from E. chaffeensis or E. ewingii and instead to be caused by a newly discovered ehrlichia species. All patients had fever, malaise, headache, and lymphopenia; three had thrombocytopenia; and two had elevated liver-enzyme levels. All recovered after receiving doxycycline treatment. At least 17 of 697 Ixodes scapularis ticks collected in Minnesota or Wisconsin were positive for the same ehrlichia species on polymerase-chain-reaction testing. Genetic analyses revealed that this new ehrlichia species is closely related to E. muris., Conclusions: We report a new ehrlichia species in Minnesota and Wisconsin and provide supportive clinical, epidemiologic, culture, DNA-sequence, and vector data. Physicians need to be aware of this newly discovered close relative of E. muris to ensure appropriate testing, treatment, and regional surveillance. (Funded by the National Institutes of Health and the Centers for Disease Control and Prevention.).

Ehrlichia chaffeensis causes human monocytic ehrlichiosis, and Anaplasma phagocytophilum causes human granulocytic anaplasmosis. These related tick-borne rickettsial organisms can cause severe and fatal illness. During 2000-2007, the reported incidence rate of E. chaffeensis increased from 0.80 to 3.0 cases/million persons/year. The case-fatality rate was 1.9%, and the hospitalization rate was 49%. During 2000-2007, the reported incidence of A. phagocytophilum increased from 1.4 to 3.0 cases/million persons/year. The case-fatality rate was 0.6%, and the hospitalization rate was 36%. Rates among female patients were lower than among male patients for ehrlichiosis (rate ratio = 0.68) and anaplasmosis (rate ratio = 0.70). Most (80%) ehrlichiosis and anaplasmosis cases met only a probable case definition, although, use of a polymerase chain reaction to confirm infections increased during 2000-2007. Heightened reporting of these diseases will likely continue with improving recognition, changing surveillance practices, and appropriate application of diagnostic assays.

Since 2003, two communities in eastern Arizona have experienced a sustained outbreak of Rocky Mountain spotted fever (RMSF), caused by Rickettsia rickettsii, associated with transmission by Rhipicephalus sanguineus, the brown dog tick; 70 human cases, including eight deaths, were reported from these communities during 2003 through 2008. In both of the affected communities, antibodies to spotted fever group rickettsiae (SFGR) were present in dogs before the notice of the first human cases, suggesting that dogs may serve as useful sentinels for human risk of RMSF in this region. During 2005 and 2006, an exploratory serosurvey was conducted among stray and relinquished dogs presenting to animal control facilities in eastern Arizona located outside the area where human cases had been reported. Antibodies to SFGR were detected in 5.7% (14 of 247) dogs assessed outside the RMSF outbreak area. Animal shelters located in counties that either included or shared large borders with the outbreak area were significantly more likely to have seropositive dogs than facilities in more geographically separated counties (P = 0.01). In addition, stray dogs were significantly more likely to be antibody-positive than relinquished animals (P = 0.01), suggesting that control of stray dog populations should be considered as a means of limiting SFGR transmission in this region. The findings from this study may be extrapolated to suggest that the current risk for human RMSF infection may extend beyond the noted outbreak area. Heightened surveillance for human disease is needed in the region., (Published 2009. This article is a US Government work and is in the public domain in the USA.)

Recrudescent Rickettsia prowazekii infection, also known as Brill-Zinsser disease, can manifest decades after untreated primary infection but is rare in contemporary settings. We report the first known case of Brill-Zinsser disease in a patient originally infected with a zoonotic strain of R. prowazekii acquired from flying squirrels.

Rocky Mountain spotted fever (RMSF), a potentially fatal tick-borne infection caused by Rickettsia rickettsii, is considered a notifiable condition in the United States. During 2000 to 2007, the annual reported incidence of RMSF increased from 1.7 to 7 cases per million persons from 2000 to 2007, the highest rate ever recorded. American Indians had a significantly higher incidence than other race groups. Children 5-9 years of age appeared at highest risk for fatal outcome. Enzyme-linked immunosorbent assays became more widely available beginning in 2004 and were used to diagnose 38% of cases during 2005-2007. The proportion of cases classified as confirmed RMSF decreased from 15% in 2000 to 4% in 2007. Concomitantly, case fatality decreased from 2.2% to 0.3%. The decreasing proportion of confirmed cases and cases with fatal outcome suggests that changes in diagnostic and surveillance practices may be influencing the observed increase in reported incidence rates.

Dogs and people are exposed to and susceptible to infection by many of the same tick-borne bacterial pathogens in the order Rickettsiales, including Anaplasma phagocytophilum, Ehrlichia canis, E. chaffeensis, E. ewingii, Rickettsia rickettsii, R. conorii, and other spotted fever group rickettsiae. Recent findings include descriptions of novel Ehrlichia and Rickettsia species, recognition of the occurrence and clinical significance of co-infection, and increasing awareness of Rhipicephalus sanguineus-associated diseases. Newer molecular assays are available, although renewed efforts to encourage their use are needed. This review highlights the ecology and epidemiology of these diseases, and proposes avenues for future investigation., (Published by Elsevier Ltd.)

Cat-scratch disease, flea-borne typhus, and plague are three flea-associated zoonoses of cats of concern in the USA. Although flea concentrations may be heaviest in coastal and temperate climates, fleas and flea-borne disease agents can occur almost anywhere in the USA. Understanding flea-borne pathogens, and the associated risks for owners and veterinarians, is important to reduce the likelihood of zoonotic infection., (Published by Elsevier Ltd.)

Background: In October 2007, a cluster of patients experiencing a novel polyradiculoneuropathy was identified at a pork abattoir (Plant A). Patients worked in the primary carcass processing area (warm room); the majority processed severed heads (head-table). An investigation was initiated to determine risk factors for illness., Methods and Results: Symptoms of the reported patients were unlike previously described occupational associated illnesses. A case-control study was conducted at Plant A. A case was defined as evidence of symptoms of peripheral neuropathy and compatible electrodiagnostic testing in a pork abattoir worker. Two control groups were used - randomly selected non-ill warm-room workers (n = 49), and all non-ill head-table workers (n = 56). Consenting cases and controls were interviewed and blood and throat swabs were collected. The 26 largest U.S. pork abattoirs were surveyed to identify additional cases. Fifteen cases were identified at Plant A; illness onsets occurred during May 2004-November 2007. Median age was 32 years (range, 21-55 years). Cases were more likely than warm-room controls to have ever worked at the head-table (adjusted odds ratio [AOR], 6.6; 95% confidence interval [CI], 1.6-26.7), removed brains or removed muscle from the backs of heads (AOR, 10.3; 95% CI, 1.5-68.5), and worked within 0-10 feet of the brain removal operation (AOR, 9.9; 95% CI, 1.2-80.0). Associations remained when comparing head-table cases and head-table controls. Workers removed brains by using compressed air that liquefied brain and generated aerosolized droplets, exposing themselves and nearby workers. Eight additional cases were identified in the only two other abattoirs using this technique. The three abattoirs that used this technique have stopped brain removal, and no new cases have been reported after 24 months of follow up. Cases compared to controls had higher median interferon-gamma (IFNgamma) levels (21.7 pg/ml; vs 14.8 pg/ml, P<0.001)., Discussion: This novel polyradiculoneuropathy was associated with removing porcine brains with compressed air. An autoimmune mechanism is supported by higher levels of IFNgamma in cases than in controls consistent with other immune mediated illnesses occurring in association with neural tissue exposure. Abattoirs should not use compressed air to remove brains and should avoid procedures that aerosolize CNS tissue. This outbreak highlights the potential for respiratory or mucosal exposure to cause an immune-mediated illness in an occupational setting.

To examine trends of Rocky Mountain spotted fever (RMSF) incidence among American Indians compared with other race groups, a retrospective analysis of national RMSF surveillance data reported to the National Electronic Telecommunications System for Surveillance and the Tickborne Rickettsial Disease Case Report Forms system were used. The RMSF incidence for American Indians, which was comparable to those for other race groups during 1990-2000, increased at a disproportionate rate during 2001-2005. The average annual incidence of RMSF reported among American Indians for 2001-2005 was 16.8 per 1,000,000 persons compared with 4.2, 2.6, and 0.5 for white, black, and Asian/Pacific Islander persons, respectively. Most cases in American Indians were reported from Oklahoma (113.1 cases per 1,000,000), North Carolina (60.0), and Arizona (17.2). The incidence of RMSF increased dramatically among American Indians disproportionately to trends for other race groups. Education about tick-borne disease and prevention measures should be addressed for high-risk American Indian populations.

The importation of dogs into the United States poses a risk for the introduction of rabies and other zoonotic diseases. Federal regulations (42 CFR 71.51) currently require proof of valid rabies vaccination for imported dogs, but allow the importation of some unvaccinated dogs, including dogs less than 3 months of age, provided certain requirements for confinement are met until the dog is vaccinated. Although there are no accurate surveillance data on the number of dogs imported each year, it is estimated based on extrapolated data that over 287,000 dogs were imported into the United States during 2006. Of these, approximately 25% were either too young to be vaccinated or lacked proof of valid rabies vaccination. Import trends suggest that an increasing number of unvaccinated puppies are being imported into the United States, many through commercial resale or rescue operations. Since 2004, foreign canine rabies virus variants have been documented in at least two imported puppies. Federal regulations are currently being reviewed by the Centers for Disease Control and Prevention to determine if they can be updated to address current import trends and disease risks, such as requiring a health screen and valid rabies vaccinations for all dogs prior to entry.

OBJECTIVE-To assess the knowledge and use of infection control practices (ICPs) among US veterinarians. DESIGN-Anonymous mail-out population survey. PROCEDURES-In 2005 a questionnaire was mailed to US small animal, large animal, and equine veterinarians who were randomly selected from the AVMA membership to assess precaution awareness (PA) and veterinarians' perceptions of zoonotic disease risks. Respondents were assigned a PA score (0 to 4) on the basis of their responses (higher scores representing higher stringency of ICPs); within a practice type, respondents' scores were categorized as being within the upper 25% or lower 75% of scores (high and low PA ranking, respectively). Characteristics associated with low PA rankings were assessed. RESULTS-Generally, respondents did not engage in protective behaviors or use personal protective equipment considered appropriate to protect against zoonotic disease transmission. Small animal and equine veterinarians employed in practices that had no written infection control policy were significantly more likely to have low PA ranking. Male gender was associated with low PA ranking among small animal and large animal veterinarians; equine practitioners not working in a teaching or referral hospital were more likely to have low PA ranking than equine practitioners working in such institutions. CONCLUSIONS AND CLINICAL RELEVANCE-Results indicated that most US veterinarians are not aware of appropriate personal protective equipment use and do not engage in practices that may help reduce zoonotic disease transmission. Gender differences may influence personal choices for ICPs. Provision of information and training on ICPs and establishment of written infection control policies could be effective means of improving ICPs in veterinary practices.

During 2002 through 2004, 15 patients with Rocky Mountain spotted fever (RMSF) were identified in a rural community in Arizona where the disease had not been previously reported. The outbreak was associated with Rickettsia rickettsii in an unexpected tick vector, the brown dog tick (Rhipicephalus sanguineus), which had not been previously associated with RMSF transmission in the United States. We investigated the extent of exposure to R. rickettsii in the local area through serologic evaluations of children and dogs in 2003-2004, and in canine sera from 1996. Antibodies to R. rickettsii at titers > or = 32 were detected in 10% of children and 70% of dogs in the outbreak community and 16% of children and 57% of dogs in a neighboring community. In comparison, only 5% of canine samples from 1996 had anti-R. rickettsii antibodies at titers > or = 32. These results suggest that exposures to RMSF have increased over the past 9 years, and that RMSF may now be endemic in this region.

The epidemiologic features are described of cases of human monocytic ehrlichiosis and human granulocytic anaplasmosis in the United States.

The increased incidence of Rocky Mountain spotted fever (RMSF) in 1997-2002 compared with previous years may be related to enhanced awareness and reporting of RMSF as well as changes in human-vector interaction. However, reports on RMSF mortality underscore the need for physician vigilance in considering a diagnosis of RMSF for febrile individuals potentially exposed to ticks and stress the importance of treating such persons regardless of the presence of a rash.

Although Q fever is considered enzootic in the United States, surveillance for human Q fever has been historically limited. From 1978 through 1999, 436 cases (average = 20 per year) of human Q fever were reported. After Q fever became nationally reportable in 1999, 255 human Q fever cases (average = 51 per year) were reported with illness onset during 2000 through 2004. The median age of cases was 51 years, and most cases were male (77%). The average annual incidence of Q fever was 0.28 cases per million persons, and was highest in persons 50-59 years of age (0.39 cases per million). State-specific incidence ranged from a high of 2.40 cases per million persons in Wyoming, to 0 cases in some states. Since Q fever became reportable, case reports have increased by more than 250%. Surveillance for Q fever is essential to establish the distribution and magnitude of disease and to complement U.S. bioterrorism preparedness activities.

Tickborne rickettsial diseases (TBRD) continue to cause severe illness and death in otherwise healthy adults and children, despite the availability of low cost, effective antimicrobial therapy. The greatest challenge to clinicians is the difficult diagnostic dilemma posed by these infections early in their clinical course, when antibiotic therapy is most effective. Early signs and symptoms of these illnesses are notoriously nonspecific or mimic benign viral illnesses, making diagnosis difficult. In October 2004, CDC's Viral and Rickettsial Zoonoses Branch, in consultation with 11 clinical and academic specialists of Rocky Mountain spotted fever, human granulocytotropic anaplasmosis, and human monocytotropic ehrlichiosis, developed guidelines to address the need for a consolidated source for the diagnosis and management of TBRD. The preparers focused on the practical aspects of epidemiology, clinical assessment, treatment, and laboratory diagnosis of TBRD. This report will assist clinicians and other health-care and public health professionals to 1) recognize epidemiologic features and clinical manifestations of TBRD, 2) develop a differential diagnosis that includes and ranks TBRD, 3) understand that the recommendations for doxycycline are the treatment of choice for both adults and children, 4) understand that early empiric antibiotic therapy can prevent severe morbidity and death, and 5) report suspect or confirmed cases of TBRD to local public health authorities to assist them with control measures and public health education efforts.

Scrub typhus, caused by Orientia tsutsugamushi, is a severe febrile illness transmitted to humans by trombiculid mites, which normally feed on rodents. The first known outbreak of scrub typhus in Palau occurred in 2001 to 2003 among residents of the remote southwest islands. To determine the extent of scrub typhus distribution in Palau, we tested serum samples from humans and rodents for antibodies to O. tsutsugamushi. Of 212 Palau residents surveyed in 2003, 101 (47.6%) had immunoglobulin G (IgG) antibody titers >1:64, and 56 (26.4%) had concurrent IgG and IgM antibody titers >1:512 and 1:64, respectively. Of 635 banked serum samples collected from Palau residents in 1995, 34 (5.4%) had IgG antibody titers >1:64. Sera collected from rodents (Rattus norvegicus and R. rattus) in 2003 and 2005 were tested, and 18 (28.6%) of 63 had IgG antibody titers >1:64. These findings suggest that scrub typhus is endemic in Palau.

Background: Rocky Mountain spotted fever is a life-threatening, tick-borne disease caused by Rickettsia rickettsii. This disease is rarely reported in Arizona, and the principal vectors, Dermacentor species ticks, are uncommon in the state. From 2002 through 2004, a focus of Rocky Mountain spotted fever was investigated in rural eastern Arizona., Methods: We obtained blood and tissue specimens from patients with suspected Rocky Mountain spotted fever and ticks from patients' homesites. Serologic, molecular, immunohistochemical, and culture assays were performed to identify the causative agent. On the basis of specific laboratory criteria, patients were classified as having confirmed or probable Rocky Mountain spotted fever infection., Results: A total of 16 patients with Rocky Mountain spotted fever infection (11 with confirmed and 5 with probable infection) were identified. Of these patients, 13 (81 percent) were children 12 years of age or younger, 15 (94 percent) were hospitalized, and 2 (12 percent) died. Dense populations of Rhipicephalus sanguineus ticks were found on dogs and in the yards of patients' homesites. All patients with confirmed Rocky Mountain spotted fever had contact with tick-infested dogs, and four had a reported history of tick bite preceding the illness. R. rickettsii DNA was detected in nonengorged R. sanguineus ticks collected at one home, and R. rickettsii isolates were cultured from these ticks., Conclusions: This investigation documents the presence of Rocky Mountain spotted fever in eastern Arizona, with common brown dog ticks (R. sanguineus) implicated as a vector of R. rickettsii. The broad distribution of this common tick raises concern about its potential to transmit R. rickettsii in other settings., (Copyright 2005 Massachusetts Medical Society.)

Background: Cat-scratch disease (CSD), caused by infection with Bartonella henselae, affects both children and adults but is principally a pediatric disease. Typical CSD is generally benign and self-limited and is characterized by regional lymphadenopathy with fever. Infections can, however, be accompanied by focal or diffuse inflammatory responses (atypical CSD) involving neurologic, organ (liver/spleen), lymphatic or skeletal systems., Methods: Pediatric hospitalizations with CSD listed as a diagnosis were examined using the Kids' Inpatient Database for the year 2000. National estimates of CSD-associated hospitalizations, hospitalization rates and various hospitalization statistics were examined for patients younger than 18 years of age., Results: During 2000, an estimated 437 (SE 43) pediatric hospitalizations associated with CSD occurred among children younger than 18 years of age in the United States. The national CSD-associated hospitalization rate was 0.60/100,000 children younger than 18 years of age (95% confidence interval, 0.49-0.72) and 0.86/100,000 children younger than 5 years of age (95% CI 0.64-1.07). Accompanying diagnoses included neurologic complications (12%), organ (liver/spleen) involvement (7%) and "other" (5%). Atypical CSD accounted for approximately 24% of the CSD-associated hospitalizations. The median charge for a CSD-associated hospitalization was 6140 dollars with total annual hospital charges of approximately 3.5 million dollars among children in the United States., Conclusions: The CSD-associated hospitalization rate among children during 2000 appeared similar to those estimated for the 1980s in the United States, despite significant increases in cat ownership in the intervening time. Early serologic and molecular testing for CSD in children is suggested to minimize unnecessary interventions and promote optimally effective care when supportive measures are required.

During 2001 through 2002, 1,176 cases of the tick-borne diseases human monocytic ehrlichiosis (HME) and human granulocytic anaplasmosis (HGA) were reported to the Centers for Disease Control and Prevention (CDC) by 32 states through the National Electronic Telecommunications System for Surveillance. The average reported annual incidences for HME and HGA during 2001-2002 were 0.6 and 1.4 cases per million population, respectively; incidence was highest among men > 60 years of age. During this same interval, a total of 883 cases of HME and HGA were reported to CDC through a passive surveillance system of tick-borne disease case report forms (CRFs). The surveillance information retrieved from CRFs has allowed for qualitative evaluation of ehrlichiosis and anaplasmosis risk factors, severity, and diagnostic accuracy. Although these surveillance systems likely substantially under-represent the true burden of ehrlichiosis and anaplasmosis in the United States due to poor recognition and reporting, they represent the first compilation of national data since these diseases were made nationally notifiable. Continued and improved surveillance activities will progressively reinforce our understanding and awareness of these newly recognized zoonotic infections.

Prevalence of antibodies to Coxiella burnetii in 24 veterinary school-associated dairy herds in the United States was assessed through laboratory testing of bulk tank milk specimens by indirect immunofluorescent antibody assay. Twenty-two herds (92%) had evidence of antibodies to C. burnetii Phase I antibodies at a titer of > or = 1:16, and nine herds (38%) had Phase I antibody titers of > or = 1:256. These results suggest that C. burnetii infection is geographically widespread among dairy herds in the United States.

Objective: To identify risk factors associated with the spread of low pathogenicity H7N2 avian influenza (AI) virus among commercial poultry farms in western Virginia during an outbreak in 2002., Design: Case-control study., Procedure: Questionnaires were used to collect information about farm characteristics, biosecurity measures, and husbandry practices on 151 infected premises (128 turkey and 23 chicken farms) and 199 noninfected premises (167 turkey and 32 chicken farms)., Results: The most significant risk factor for AI infection was disposal of dead birds by rendering (odds ratio [OR], 73). In addition, age > or = 10 weeks (OR for birds aged 10 to 19 weeks, 4.9; OR for birds aged > or = 20 weeks, 4.3) was a significant risk factor regardless of poultry species involved. Other significant risk factors included use of nonfamily caretakers and the presence of mammalian wildlife on the farm. Factors that were not significantly associated with infection included use of various routine biosecurity measures, food and litter sources, types of domestic animals on the premises, and presence of wild birds on the premises., Conclusions and Clinical Relevance: Results suggest that an important factor contributing to rapid early spread of AI virus infection among commercial poultry farms during this outbreak was disposal of dead birds via rendering off-farm. Because of the highly infectious nature of AI virus and the devastating economic impact of outbreaks, poultry farmers should consider carcass disposal techniques that do not require off-farm movement, such as burial, composting, or incineration.

The increasing popularity of foreign travel and ecotourism places travelers at increased risk for certain tick-borne diseases. From 1999 through 2002, 31 cases of imported spotted fever-group rickettsioses (SFGR) in United States residents reporting travel to Africa were confirmed by laboratory testing at the Centers for Disease Control and Prevention. Nineteen patients (61%) reported visiting South Africa prior to illness onset. Most patients reported fever and one or more eschars; rash was reported for only 26% of the patients. Twelve patients had an initial non-reactive acute-phase serum sample obtained a median of three days after illness onset, and were confirmed by testing a second convalescent-phase serum sample obtained a median of 32 days after illness onset. Five patients were confirmed positive through immunohistochemical staining of skin biopsies, including three patients with acute-phase serum samples that tested negative for SFGR. This study emphasizes the importance of evaluating convalescent-phase serum specimens 28 days or more after illness onset or examining skin biopsies by immunohistochemical staining during early infection to confirm a diagnosis of imported SFGR.