Health Care Provider Knowledge Regarding Alpha-gal Syndrome - United States, March-May 2022.

Alpha-gal syndrome (AGS) is an emerging, tick bite-associated immunoglobulin E-mediated allergic condition characterized by a reaction to the oligosaccharide galactose-alpha-1,3-galactose (alpha-gal), which is found in mammalian meat and products derived from mammals, including milk, other dairy products, and some pharmaceutical products. Symptoms range from mild (e.g., a rash or gastrointestinal upset) to severe (anaphylaxis); onset typically occurs ≥2 hours after exposure to alpha-gal. No treatment or cure is currently available. Despite the potential life-threating reactions associated with AGS, most patients perceive that health care providers (HCPs) have little or no knowledge of AGS. A U.S. web-based survey of 1,500 HCPs revealed limited knowledge of AGS, identified areas for continuing medical education, and described self-reported diagnostic and management practices. Overall, 42% of surveyed HCPs had never heard of AGS, and among those who had, fewer than one third knew how to diagnose the condition. Two thirds of respondents indicated that guidelines for the diagnosis and management of AGS would be useful clinical resources. Limited awareness and knowledge of AGS among HCPs likely contributes to underdiagnosis of this condition and inadequate patient management, and underestimates of the number of AGS patients in the United States, which currently relies on laboratory testing data alone.

Morbidity and Functional Outcomes Following Rocky Mountain Spotted Fever Hospitalization-Arizona, 2002-2017.

Background: Rocky Mountain spotted fever (RMSF) is a deadly tickborne disease disproportionately affecting Arizona tribal communities. While the acute clinical effects of RMSF are well-documented, more complete understanding of the long-term health consequences is needed to provide guidance for providers and patients in highly impacted areas. Methods: We performed a retrospective review of hospitalized RMSF cases from 2 tribal communities in Arizona during 2002-2017. Medical records from acute illness were abstracted for information on clinical presentation, treatment, and status at discharge. Surviving patients were interviewed about disease recovery, and patients reporting incomplete recovery were eligible for a neurologic examination. Results: Eighty hospitalized cases of RMSF met our inclusion criteria and were reviewed. Of these, 17 (21%) resulted in a fatal outcome. Among surviving cases who were interviewed, most (62%) reported full recovery, 15 (38%) reported ongoing symptoms or reduced function following RMSF illness, and 9 (23%) had evidence of neurologic sequelae at the time of examination. Sequelae included impaired cognition, weakness, decreased deep tendon reflexes, seizures, and cranial nerve dysfunction. Longer hospitalization (25.5 days vs 6.2 days, P < .001), a higher degree of disability at discharge (median modified Rankin score 1 vs 0, P = .03), and delayed doxycycline administration (6.2 days vs 4.1 days, P = .12) were associated with long-term sequelae by logistic regression. Conclusions: Although the etiology of sequelae is not able to be determined using this study design, life-altering sequelae were common among patients surviving severe RMSF illness. Delayed administration of the antibiotic doxycycline after day 5 was the strongest predictor of morbidity.

Ehrlichiosis and Anaplasmosis among Transfusion and Transplant Recipients in the United States.

Ehrlichiosis and anaplasmosis are emerging tickborne diseases that can also be transmitted through blood transfusions or organ transplants. Since 2000, ehrlichiosis and anaplasmosis cases in the United States have increased substantially, resulting in potential risk to transplant and transfusion recipients. We reviewed ehrlichiosis and anaplasmosis cases among blood transfusion and solid organ transplant recipients in the United States from peer-reviewed literature and Centers for Disease Control and Prevention investigations. We identified 132 cases during 1997-2020, 12 transfusion-associated cases and 120 cases in transplant recipients; 8 cases were donor-derived, and in 13 cases illness occurred <1 year after transplant. Disease in the remaining 99 cases occurred ≥1 year after transplant, suggesting donor-derived disease was unlikely. Severe illness or death were reported among 15 transfusion and transplant recipients. Clinicians should be alert for these possible infections among transfusion and transplant recipients to prevent severe complications or death by quickly treating them.

Seroprevalence of spotted fever group rickettsiae in canines along the United States-Mexico border.

Portions of northern Mexico are experiencing a re-emergence of Rocky Mountain spotted fever (RMSF), a tickborne disease caused by Rickettsia rickettsii, a member of the spotted fever group of rickettsiae (SFGR). Infection with R. rickettsii can result in serious and life-threatening illness in people and dogs. Canine seroprevalence has been used as a sentinel for human RMSF in previous studies. This study aims to quantify SFGR seroprevalence in canines in three northern Mexican states and identify risk factors associated with seropositivity. A total of 1,136 serum samples and 942 ticks were obtained from dogs participating in government sterilization campaigns and from animal control facilities in 14 Mexican cities in three states. SFGR antibodies were detected using indirect immunofluorescence antibody assays at titre values ≥1/64. Six per cent (69 dogs) showed antibodies to SFGR, with the highest seroprevalence reported in Baja California (12%), Coahuila (4%) and Sonora (4%). Dogs from Baja California had three times higher odds of having SFGR antibodies compared to dogs from Sonora (OR = 3.38, 95% CI, 1.81-6.37). Roughly one quarter (25%) of surveyed dogs were parasitized by ticks (Rhipicephalus sanguineus sensu lato) at the time of sample collection. A portion of collected ticks were tested for rickettsial DNA using polymerase chain reaction. Positive samples were then sequenced, showing evidence of SFGR including R. massiliae, R. parkeri and R. rickettsii. Dogs that spent the majority of time on the street, such as free-roaming or community-owned dogs, showed a greater risk of tick infestation, seropositivity, bearing seropositive ticks, and may play a pivotal role in the spread of SFGR among communities. Estimating the seroprevalence of SFGR in the canine population can help public health campaigns target high-risk communities for interventions to reduce human RMSF cases.

Diagnostic Methods Used to Classify Confirmed and Probable Cases of Spotted Fever Rickettsioses - United States, 2010-2015.

Spotted fever rickettsioses (SFR), including Rocky Mountain spotted fever (RMSF), are nationally notifiable diseases in the United States caused by spotted fever group Rickettsia. The annual incidence of SFR increased from 1.7 cases per 1 million persons in 2000 to 13.2 in 2016 (1,2). Although this demonstrates a substantial increase in SFR cases, the actual magnitude of the increase is questionable because the current case definition allows for nonspecific laboratory criteria to support diagnosis (3). To analyze the quality of laboratory data used to support the diagnosis of SFR cases with illness onset during 2010-2015, CDC examined supplementary case report forms. Among 16,807 reported cases, only 167 (1.0%) met the confirmed case definition, and the remaining 16,640 (99.0%) met the probable case definition. The most common supportive laboratory evidence for probable cases was elevated immunoglobulin G (IgG) antibody titer by indirect immunofluorescence assay (IFA), which was reported for 14,784 (88.8%) probable cases. Antibodies to spotted fever group Rickettsia can persist for months or years following infection, making a single antibody titer unreliable for diagnosing incident disease without a convalescent specimen. Increased use of molecular assays and use of paired and appropriately timed IFA IgG testing practices could improve understanding of SFR epidemiology and increase the accuracy of disease incidence estimates.

Vital Signs: Trends in Reported Vectorborne Disease Cases - United States and Territories, 2004-2016.

INTRODUCTION: Vectorborne diseases are major causes of death and illness worldwide. In the United States, the most common vectorborne pathogens are transmitted by ticks or mosquitoes, including those causing Lyme disease; Rocky Mountain spotted fever; and West Nile, dengue, and Zika virus diseases. This report examines trends in occurrence of nationally reportable vectorborne diseases during 2004-2016. METHODS: Data reported to the National Notifiable Diseases Surveillance System for 16 notifiable vectorborne diseases during 2004-2016 were analyzed; findings were tabulated by disease, vector type, location, and year. RESULTS: A total 642,602 cases were reported. The number of annual reports of tickborne bacterial and protozoan diseases more than doubled during this period, from >22,000 in 2004 to >48,000 in 2016. Lyme disease accounted for 82% of all tickborne disease reports during 2004-2016. The occurrence of mosquitoborne diseases was marked by virus epidemics. Transmission in Puerto Rico, the U.S. Virgin Islands, and American Samoa accounted for most reports of dengue, chikungunya, and Zika virus diseases; West Nile virus was endemic, and periodically epidemic, in the continental United States. CONCLUSIONS AND IMPLICATIONS FOR PUBLIC HEALTH PRACTICE: Vectorborne diseases are a large and growing public health problem in the United States, characterized by geographic specificity and frequent pathogen emergence and introduction. Differences in distribution and transmission dynamics of tickborne and mosquitoborne diseases are often rooted in biologic differences of the vectors. To effectively reduce transmission and respond to outbreaks will require major national improvement of surveillance, diagnostics, reporting, and vector control, as well as new tools, including vaccines.

Fatal Rocky Mountain Spotted Fever along the United States-Mexico Border, 2013-2016.

Rocky Mountain spotted fever (RMSF) is an emerging public health concern near the US-Mexico border, where it has resulted in thousands of cases and hundreds of deaths in the past decade. We identified 4 patients who had acquired RMSF in northern Mexico and subsequently died at US healthcare facilities. Two patients sought care in Mexico before being admitted to US-based hospitals. All patients initially had several nonspecific signs and symptoms, including fever, headache, nausea, vomiting, or myalgia, but deteriorated rapidly without receipt of a tetracycline-class antimicrobial drug. Each patient experienced respiratory failure late in illness. Although transborder cases are not common, early recognition and prompt initiation of appropriate treatment are vital for averting severe illness and death. Clinicians on both sides of the US-Mexico border should consider a diagnosis of RMSF for patients with rapidly progressing febrile illness and recent exposure in northern Mexico.

Fatal Flea-Borne Typhus in Texas: A Retrospective Case Series, 1985-2015.

AbstractFlea-borne (murine) typhus is a global rickettsiosis caused by Rickettsia typhi. Although flea-borne typhus is no longer nationally notifiable, cases are reported for surveillance purposes in a few U.S. states. The infection is typically self-limiting, but may be severe or life-threatening in some patients. We performed a retrospective review of confirmed or probable cases of fatal flea-borne typhus reported to the Texas Department of State Health Services during 1985-2015. When available, medical charts were also examined. Eleven cases of fatal flea-borne typhus were identified. The median patient age was 62 years (range, 36-84 years) and 8 (73%) were male. Patients presented most commonly with fever (100%), nausea and vomiting (55%), and rash (55%). Respiratory (55%) and neurologic (45%) manifestations were also identified frequently. Laboratory abnormalities included thrombocytopenia (82%) and elevated hepatic transaminases (63%). Flea or animal contact before illness onset was frequently reported (55%). The median time from hospitalization to administration of a tetracycline-class drug was 4 days (range, 0-5 days). The median time from symptom onset to death was 14 days (range, 1-34 days). Flea-borne typhus can be a life-threatening disease if not treated in a timely manner with appropriate tetracycline-class antibiotics. Flea-borne typhus should be considered in febrile patients with animal or flea exposure and respiratory or neurologic symptoms of unknown etiology.

Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain Spotted Fever and Other Spotted Fever Group Rickettsioses, Ehrlichioses, and Anaplasmosis - United States.

Tickborne rickettsial diseases continue to cause severe illness and death in otherwise healthy adults and children, despite the availability of low-cost, effective antibacterial therapy. Recognition early in the clinical course is critical because this is the period when antibacterial therapy is most effective. Early signs and symptoms of these illnesses are nonspecific or mimic other illnesses, which can make diagnosis challenging. Previously undescribed tickborne rickettsial diseases continue to be recognized, and since 2004, three additional agents have been described as causes of human disease in the United States: Rickettsia parkeri, Ehrlichia muris-like agent, and Rickettsia species 364D. This report updates the 2006 CDC recommendations on the diagnosis and management of tickborne rickettsial diseases in the United States and includes information on the practical aspects of epidemiology, clinical assessment, treatment, laboratory diagnosis, and prevention of tickborne rickettsial diseases. The CDC Rickettsial Zoonoses Branch, in consultation with external clinical and academic specialists and public health professionals, developed this report to assist health care providers and public health professionals to 1) recognize key epidemiologic features and clinical manifestations of tickborne rickettsial diseases, 2) recognize that doxycycline is the treatment of choice for suspected tickborne rickettsial diseases in adults and children, 3) understand that early empiric antibacterial therapy can prevent severe disease and death, 4) request the appropriate confirmatory diagnostic tests and understand their usefulness and limitations, and 5) report probable and confirmed cases of tickborne rickettsial diseases to public health authorities.

Coxiella burnetii Infection in a Community Operating a Large-Scale Cow and Goat Dairy, Missouri, 2013.

Coxiella burnetii is a zoonotic pathogen that causes Q fever in humans and is transmitted primarily from infected goats, sheep, or cows. Q fever typically presents as an acute febrile illness; however, individuals with certain predisposing conditions, including cardiac valvulopathy, are at risk for chronic Q fever, a serious manifestation that may present as endocarditis. In response to a cluster of Q fever cases detected by public health surveillance, we evaluated C. burnetii infection in a community that operates a large-scale cow and goat dairy. A case was defined as an individual linked to the community with a C. burnetii phase II IgG titer ≥ 128. Of 135 participants, 47 (35%) cases were identified. Contact with or close proximity to cows, goats, and their excreta was associated with being a case (relative risk 2.7, 95% confidence interval 1.3-5.3). Cases were also identified among individuals without cow or goat contact and could be related to windborne spread or tracking of C. burnetii on fomites within the community. A history of injection drug use was reported by 26/130 (20%) participants; follow-up for the presence of valvulopathy and monitoring for development of chronic Q fever may be especially important among this population.

National Surveillance of Spotted Fever Group Rickettsioses in the United States, 2008-2012.

Spotted fever group (SFG) rickettsioses are notifiable conditions in the United States caused by the highly pathogenic Rickettsia rickettsii and less pathogenic rickettsial species such as Rickettsia parkeri and Rickettsia sp. 364D. Surveillance data from 2008 to 2012 for SFG rickettsioses are summarized. Incidence increased from 1.7 cases per million person-years (PY) in 2000 to 14.3 cases per million PY in 2012. During 2008-2012, cases of SFG rickettsiosis were more frequently reported among males, persons of white race, and non-Hispanic ethnicity. Overall, case fatality rate (CFR) was low (0.4%), however, risk of death was significantly higher for American Indian/Alaska Natives (relative risk [RR] = 5.4) and Asian/Pacific Islanders (RR = 5.7) compared with persons of white race. Children aged < 10 years continue to experience the highest CFR (1.6%). Higher incidence of SFG rickettsioses and decreased CFR likely result from increased reporting of tick-borne disease including those caused by less pathogenic species. Recently, fewer cases have been confirmed using species-specific laboratory methods (such as cell culture and DNA detection using polymerase chain reaction [PCR] assays), causing a clouded epidemiological picture. Use of PCR and improved documentation of clinical signs, such as eschars, will better differentiate risk factors, incidence, and clinical outcomes of specific rickettsioses in the future.

Increasing Incidence of Ehrlichiosis in the United States: A Summary of National Surveillance of Ehrlichia chaffeensis and Ehrlichia ewingii Infections in the United States, 2008-2012.

Human ehrlichiosis is a potentially fatal disease caused by Ehrlichia chaffeensis and Ehrlichia ewingii. Cases of ehrlichiosis are reported to Centers for Disease Control and Prevention through two national surveillance systems: Nationally Notifiable Diseases Surveillance System (NNDSS) and Case Report Forms. During 2008-2012, 4,613 cases of E. chaffeensis infections were reported through NNDSS. The incidence rate (IR) was 3.2 cases per million person-years (PYs). The hospitalization rate (HR) was 57% and the case fatality rate (CFR) was 1%. Children aged < 5 years had the highest CFR of 4%. During 2008-2012, 55 cases of E. ewingii infection were reported through NNDSS. The national IR was 0.04 cases per million PY. The HR was 77%; no deaths were reported. Immunosuppressive conditions were reported by 26% of cases. The overall rate for ehrlichiosis has increased 4-fold since 2000. Although previous literature suggests E. ewingii primarily affects those who are immunocompromised, this report shows most cases occurred among immunocompetent patients. This is the first report to show children aged < 5 years with ehrlichiosis have an increased CFR, relative to older patients. Ongoing surveillance and reporting of tick-borne diseases are critical to inform public health practice and guide disease treatment and prevention efforts.

Medical and Indirect Costs Associated with a Rocky Mountain Spotted Fever Epidemic in Arizona, 2002-2011.

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.

Human granulocytic anaplasmosis in the United States from 2008 to 2012: a summary of national surveillance data.

Human granulocytic anaplasmosis is an acute, febrile illness transmitted by the ticks Ixodes scapularis and Ixodes pacificus in the United States. We present a summary of passive surveillance data for cases of anaplasmosis with onset during 2008-2012. The overall reported incidence rate (IR) was 6.3 cases per million person-years. Cases were reported from 38 states and from New York City, with the highest incidence in Minnesota (IR = 97), Wisconsin (IR = 79), and Rhode Island (IR = 51). Thirty-seven percent of cases were classified as confirmed, almost exclusively by polymerase chain reaction. The reported case fatality rate was 0.3% and the reported hospitalization rate was 31%. IRs, hospitalization rates, life-threatening complications, and case fatality rates increased with age group. The IR increased from 2008 to 2012 and the geographic range of reported cases of anaplasmosis appears to have increased since 2000-2007. Our findings are consistent with previous case series and recent reports of the expanding range of the tick vector I. scapularis.