Danielle Stanek

Dengue outbreak in Key West, Florida, USA, 2009.

After 3 dengue cases were acquired in Key West, Florida, we conducted a serosurvey to determine the scope of the outbreak. Thirteen residents showed recent infection (infection rate 5%; 90% CI 2%–8%), demonstrating the reemergence of dengue in Florida. Increased awareness of dengue among health care providers is needed.

Genomic epidemiology reveals multiple introductions of Zika virus into the United States

Zika virus (ZIKV) is causing an unprecedented epidemic linked to severe congenital abnormalities. In July 2016, mosquito-borne ZIKV transmission was reported in the continental United States; since then, hundreds of locally acquired infections have been reported in Florida. To gain insights into the timing, source, and likely route(s) of ZIKV introduction, we tracked the virus from its first detection in Florida by sequencing ZIKV genomes from infected patients and Aedes aegypti mosquitoes. We show that at least 4 introductions, but potentially as many as 40, contributed to the outbreak in Florida and that local transmission is likely to have started in the spring of 2016—several months before its initial detection. By analysing surveillance and genetic data, we show that ZIKV moved among transmission zones in Miami. Our analyses show that most introductions were linked to the Caribbean, a finding corroborated by the high incidence rates and traffic volumes from the region into the Miami area. Our study provides an understanding of how ZIKV initiates transmission in new regions.

Cryptococcus gattii Infections in Multiple States Outside the US Pacific Northwest

Clonal VGII subtypes (outbreak strains) of Cryptococcus gattii have caused an outbreak in the US Pacific Northwest since 2004. Outbreak-associated infections occur equally in male and female patients (median age 56 years) and usually cause pulmonary disease in persons with underlying medical conditions. Since 2009, a total of 25 C. gattii infections, 23 (92%) caused by non–outbreak strain C. gattii, have been reported from 8 non–Pacific Northwest states. Sixteen (64%) patients were previously healthy, and 21 (84%) were male; median age was 43 years (range 15–83 years). Ten patients who provided information reported no past-year travel to areas where C. gattii is known to be endemic. Nineteen (76%) patients had central nervous system infections; 6 (24%) died. C. gattii infection in persons without exposure to known disease-endemic areas suggests possible endemicity in the United States outside the outbreak-affected region; these infections appear to differ in clinical and demographic characteristics from outbreak-associated C. gattii. Clinicians outside the outbreak-affected areas should be aware of locally acquired C. gattii infection and its varied signs and symptoms.

First Zika-positive donations in the continental United States

Zika virus (ZIKV) has spread in the Americas, including parts of the southern United States, and infection can be associated with serious complications, including congenital brain abnormalities. Probable transfusion transmission of ZIKV has been documented in Brazil.

Investigation of Inhalation Anthrax Case, United States

Inhalation anthrax occurred in a man who vacationed in 4 US states where anthrax is enzootic. Despite an extensive multi-agency investigation, the specific source was not detected, and no additional related human or animal cases were found. Although rare, inhalation anthrax can occur naturally in the United States.

A Confirmed Ehrlichia ewingii Infection Likely Acquired Through Platelet Transfusion

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.

Anthrax Toxin-Expressing Bacillus cereus Isolated from an Anthrax-Like Eschar.

Bacillus cereus isolates have been described harboring Bacillus anthracis toxin genes, most notably B. cereus G9241, and capable of causing severe and fatal pneumonias. This report describes the characterization of a B. cereus isolate, BcFL2013, associated with a naturally occurring cutaneous lesion resembling an anthrax eschar. Similar to G9241, BcFL2013 is positive for the B. anthracis pXO1 toxin genes, has a multi-locus sequence type of 78, and a pagA sequence type of 9. Whole genome sequencing confirms the similarity to G9241. In addition to the chromosome having an average nucleotide identity of 99.98% when compared to G9241, BcFL2013 harbors three plasmids with varying homology to the G9241 plasmids (pBCXO1, pBC210 and pBFH_1). This is also the first report to include serologic testing of patient specimens associated with this type of B. cereus infection which resulted in the detection of anthrax lethal factor toxemia, a quantifiable serum antibody response to protective antigen (PA), and lethal toxin neutralization activity.

Epidemiology of Lyme disease in low-incidence states

Lyme disease is the most common vector-borne disease in the U.S. Surveillance data from four states with a low-incidence of Lyme disease was evaluated. Most cases occurred after travel to high-incidence Lyme disease areas. Cases without travel-related exposure in low-incidence states differed epidemiologically; misdiagnosis may be common in these areas.

Malaria Prevention Knowledge, Attitudes, and Practices (KAP) Among International Flying Pilots and Flight Attendants of a US Commercial Airline

BACKGROUND In 2010, malaria caused approximately 216 million infections in people and 655,000 deaths. In the United States, imported malaria cases occur every year, primarily in returning travelers and immigrants from endemic countries. In 2010, five Plasmodium falciparum malaria cases occurred among crew members of one US commercial airline company (Airline A). This investigation aimed to assess the malaria prevention knowledge, attitudes, and practices (KAP) of Airline A crew members to provide information for potential interventions. METHODS The web link to a self-administered on-line survey was distributed by internal company communications to Airline A pilots and flight attendants (FA) eligible for international travel. The survey collected demographic information as well as occupation, work history, and malaria prevention education. RESULTS Of approximately 7,000 nonrandomly selected crew members, 220 FA and 217 pilots completed the survey (6%). Respondents correctly identified antimalarial medication (91% FA, 95% pilots) and insect repellents (96% FA, 96% pilots) as effective preventive measures. While in malaria-intense destinations, few FA and less than half of pilots always took antimalarial medication (4% FA, 40% pilots) yet many often spent greater than 30 minutes outdoors after sundown (71% FA, 66% pilots). Less than half in both groups always used insect repellents (46% FA, 47% pilots). Many respondents were unaware of how to get antimalarial medications (52% FA, 30% pilots) and were concerned about their side effects (61% FA, 31% pilots). CONCLUSION Overall, FA and pilots demonstrated good knowledge of malaria prevention, but many performed risky activities while practicing only some recommended malaria preventive measures. Malaria prevention education should focus on advance notification if traveling to a malaria-endemic area, how to easily obtain antimalarial medications, and the importance of practicing all recommended preventive measures.

Severe Leptospirosis Similar to Pandemic (H1N1) 2009, Florida and Missouri, USA

To the Editor: Leptospirosis is caused by pathogenic spirochetes of the genus Leptospira and transmitted through direct contact of skin or mucous membranes with urine or tissues of Leptospira-infected animals or through indirect contact with contaminated freshwater or soil. Leptospirosis shares common clinical signs with influenza, including fever, headache, myalgia, and sometimes cough and gastrointestinal symptoms. During 2009, acute complicated influenza-like illness (ILI) and rapid progressive pneumonia were often attributed to pandemic (H1N1) 2009; however, alternative final diagnoses were reported to be common (1). We report 3 cases of severe leptospirosis in Florida and Missouri with clinical signs similar to those of pandemic (H1N1) 2009. Patient 1 was a 40-year-old Florida man who sought treatment at an emergency department after a 4-day history of fever, myalgia, calf pain, malaise, and headache in July 2009. ILI was diagnosed. Laboratory testing was not performed, and the patient was instructed to take ibuprofen. Three days later, jaundice developed. He was admitted to an intensive-care unit with a diagnosis of hepatitis and acute renal failure. The man raised horses, goats, and chickens on his farm and was frequently employed to control rat infestations at an auto parts store and warehouse. Leptospirosis was suspected. Doxycycline was administered, and the man recovered and was discharged on the eighth day of hospitalization. Leptospira-specific immunoglobulin M antibodies were detected by dot blot (ARUP Laboratories, Salt Lake City, Utah, USA) on the second of paired consecutive blood specimens. Patient 2 was a 17-year-old Missouri woman with a history of obesity. She was hospitalized in August 2009 with a 5-day history of fever, myalgia, calf pain, malaise, headache, nausea, vomiting, dyspnea, and cough, complicated by acute renal failure. The diagnosis on admission was viral infection. On the third day of hospitalization, severe pneumonia and respiratory failure developed, and she was administered vancomycin, piperacillin/tazobactam, levofloxacin, and doxycycline. She died the same day. Ten days before illness onset, she had swum in a creek near her residence. Patient 3 was a 59-year-old Florida man with a history of obesity and diabetes mellitus. He sought treatment at a clinic in September 2009 and reported a 5-day history of fever, myalgia, malaise, nausea, abdominal pain, and dyspnea. He was treated for gastritis. Two days later, he came to an emergency department and was admitted to the hospital with severe pneumonia and multiorgan failure; he died the next day. The man had frequently engaged in activities to control rat infestations on the farm where he raised chickens, pigs, and goats. Although patients 2 and 3 were neither tested nor treated for influenza before they died, their clinical signs and rapidity of death prompted postmortem suspicion of pandemic (H1N1) 2009. Autopsies were performed and formalin-fixed tissues were submitted to the Centers for Disease Control and Prevention (Atlanta, GA, USA). Histopathologic evaluation of both patients demonstrated extensive pulmonary hemorrhage and interstitial nephritis (Figure, panels A and B), features consistent with leptospirosis. Immunohistochemical tests for leptospirosis, spotted fever group rickettsiae, and influenza A were performed on multiple tissues obtained from patients 2 and 3. Immunohistochemical evidence of leptospiral infection was identified in lung, liver, kidney, heart, and spleen tissue in both patients (Figure, panels C and D). Figure Photomicrographs of lung, liver, and kidney sections from patient 2 during study, Missouri and Florida, USA, 2009. Hematoxylin and eosin stain showed pulmonary hemorrhage (A) (original magnification ×10) and interstitial nephritis (B) (original ... These cases of severe leptospirosis were reported during the 2009 influenza pandemic. Although pulmonary hemorrhage (experienced by patients 2 and 3) is increasingly recognized as a severe manifestation of leptospirosis (2), it is also a known complication of influenza (3). ILI was initially diagnosed in patient 1, but symptom progression and clinical complications, combined with a history of animal exposure, prompted the physician to consider leptospirosis and to initiate appropriate antimicrobial drug therapy. Autopsies are critical in determining the reasons for death after undiagnosed illness. Pulmonary involvement in cases of leptospirosis is characterized by congestion and hemorrhage, usually without prominent inflammatory infiltrates (4); pulmonary involvement in cases of severe pandemic (H1N1) 2009 typically manifests as diffuse alveolar damage (5). Postmortem diagnosis of leptospirosis was supported by characteristic histopathologic findings, including pulmonary hemorrhage and interstitial nephritis, and was confirmed by immunohistochemical tests. Our report illustrates the need for autopsies in unexpected deaths, even if the cause appears obvious in a specific clinical and epidemic setting. Leptospirosis ceased being nationally notifiable in the United States in 1994 and is likely underdiagnosed because it is not routinely considered in differential diagnoses. However, outbreaks with exposures similar to the case-patients we studied have been periodically reported in the United States (6–8). Because leptospirosis commonly manifests as acute febrile illness, cases can be underrecognized during infectious-disease epidemics (e.g., dengue) (9). Leptospirosis should be included in the differential diagnosis of acute febrile illness in the United States and other industrialized countries. Epidemiologic clues include recreational or occupational water exposure; animal exposure (including rodents) in the home or the workplace, travel to tropical areas, and water exposure during travel. These risk factors for leptospirosis are increasing in industrialized countries (10). Thorough patient-history reviews and consideration of alternative diagnoses are needed for cases of respiratory illness during an influenza pandemic.