A Perilous Combination: Streptococcus Coinfection with Human Plague-Report of Two Cases and Review of the Literature, 1937-2022.

Background: Plague in humans and animals is caused by Yersinia pestis, a zoonotic gram-negative bacterium endemic in certain regions of Asia, Africa, and the United States. Coinfection with both Y. pestis and Streptococci species has been anecdotally reported in humans and associated with severe and rapidly fatal disease. Methods: This report presents two cases of patients who died following Y. pestis and Streptococcus coinfection. Additional cases of previously published Y. pestis-Streptococcus coinfection were identified and reviewed using a search of electronic databases. Results: The first case patient developed cough and dyspnea following 4 days of fever, malaise, and back pain and died before receiving medical care. Postmortem blood cultures were positive for Y. pestis, Streptococcus pyogenes, and Streptococcus dysgalactiae. The second case patient was hospitalized with fever, vomiting, diarrhea, and dyspnea and died of sepsis and respiratory failure on the day of admission. Y. pestis and Streptococcus pneumoniae were isolated from blood cultures drawn on admission. Seven additional cases of Y. pestis and Streptococcus coinfection were identified, dating between 1948 and 2009. These patients were healthy overall before their illness, with ages ranging from 9 to 60 years. The majority of patients had primary bubonic plague with associated pneumonia or septicemia. None of the patients who died received timely antimicrobial therapy directed against gram-negative pathogens. In every case but one, an occupational or environmental risk factor for plague was later identified. Conclusion: Y. pestis infection begins with a pre-inflammatory phase, during which Y. pestis and other pathogens can rapidly proliferate. Streptococci, which are frequently asymptomatic colonizers, may become invasive in this environment, leading to coinfection. The challenges of diagnosing Y. pestis in the context of coinfection may delay effective treatment. This case series and literature review illustrate the importance of clinicians remaining alert to environmental and occupational exposures in patients presenting with an infectious syndrome, especially in those who have an unexpectedly severe clinical presentation.

Francisella tularensis infection in dogs: 88 cases (2014-2016).

OBJECTIVE: To characterize the epidemiology, clinical signs, and treatment of dogs with Francisella tularensis infection in New Mexico. ANIMALS: 87 dogs in which 88 cases of tularemia (1 dog had 2 distinct cases) were confirmed by the New Mexico Department of Health Scientific Laboratory Division from 2014 through 2016 and for which medical records were available. PROCEDURES: Dogs were confirmed to have tularemia if they had a 4-fold or greater increase in anti-F tularensis antibody titer between acute and convalescent serum samples or F tularensis had been isolated from a clinical or necropsy specimen. Epidemiological, clinical, and treatment information were collected from the dogs' medical records and summarized. RESULTS: All 88 cases of tularemia were confirmed by paired serologic titers; the first (acute) serologic test result was negative for 84 (95%) cases. The most common reported exposure to F tularensis was wild rodent or rabbit contact (53/88 [60%]). Dogs had a median number of 3 clinical signs at initial evaluation; lethargy (81/88 [92%]), pyrexia (80/88 [91%]), anorexia (67/88 [76%]), and lymphadenopathy (18/88 [20%]) were most common. For 32 (36%) cases, the dog was hospitalized; all hospitalized dogs survived. CONCLUSIONS AND CLINICAL RELEVANCE: Dogs with F tularensis infection often had nonspecific clinical signs and developed moderate to severe illness, sometimes requiring hospitalization. Veterinarians examining dogs from tularemia-enzootic areas should be aware of the epidemiology and clinical signs of tularemia, inquire about potential exposures, and discuss prevention methods with owners, including reducing exposure to reservoir hosts and promptly seeking care for ill animals.

Exposure Characteristics of Hantavirus Pulmonary Syndrome Patients, United States, 1993-2015.

Those at highest risk are persons in occupations with potential for rodent exposure and American Indian women 40--64 years of age.

Yersinia pestis infection in dogs: 62 cases (2003-2011).

OBJECTIVE: To describe the epidemiology, clinical signs, and treatment practices in dogs with Yersinia pestis infection in New Mexico. DESIGN: Retrospective case series. ANIMALS: 62 dogs with plague in New Mexico. PROCEDURES: Confirmed case animals had isolation of Yersinia pestis from a clinical specimen, a positive direct fluorescent antibody test result, or a minimum 4-fold change between acute and convalescent serum antibody titers with clinically compatible illness. Retrospective review of cases of laboratory-confirmed plague from 2003 to 2011 was performed with a standardized chart abstraction form. Epidemiologic, clinical, and treatment data were evaluated. RESULTS: 62 confirmed cases of canine plague were identified from 2003 to 2011. Most cases (85%) were confirmed by serologic titers alone or in conjunction with other testing methods. Clinical signs included fever (100%), lethargy (97%), anorexia (77%), lymphadenopathy (23%), vomiting (13%), diarrhea (8%), and abscesses (2%). Most case animals (73%) were treated with multiple antimicrobials. Sixty (97%) case animals survived; of the 2 nonsurvivors, one was euthanized and another died. Potential sources of exposure to Y pestis included hunting, rodent or rabbit exposure, and residence in rural areas. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that dogs with exposure to Y pestis can develop moderate to severe illness or die as a result of infection. Veterinarians practicing in and examining animals from the western United States need to be familiar with the epidemiology of plague and query owners about potential plague exposures when consistent clinical signs are present. Veterinarians are often the first to recognize signs of plague among sentinel populations and have the opportunity to intervene and prevent zoonotic disease transmission.