Kevin S. Griffith

Investigation of bioterrorism-related anthrax, United States, 2001: epidemiologic findings.

In October 2001, the first inhalational anthrax case in the United States since 1976 was identified in a media company worker in Florida. A national investigation was initiated to identify additional cases and determine possible exposures to Bacillus anthracis. Surveillance was enhanced through health-care facilities, laboratories, and other means to identify cases, which were defined as clinically compatible illness with laboratory-confirmed B. anthracis infection. From October 4 to November 20, 2001, 22 cases of anthrax (11 inhalational, 11 cutaneous) were identified; 5 of the inhalational cases were fatal. Twenty (91%) case-patients were either mail handlers or were exposed to worksites where contaminated mail was processed or received. B. anthracis isolates from four powder-containing envelopes, 17 specimens from patients, and 106 environmental samples were indistinguishable by molecular subtyping. Illness and death occurred not only at targeted worksites, but also along the path of mail and in other settings. Continued vigilance for cases is needed among health-care providers and members of the public health and law enforcement communities.

Knowledge, Attitudes, and Behaviors Regarding Lyme Disease Prevention Among Connecticut Residents, 1999–2004

Lyme disease, caused by the tick-transmitted bacterium Borrelia burgdorferi, is the most common vector-borne disease in the United States. We surveyed residents of three Connecticut health districts to evaluate the impact of intensive community-wide education programs on knowledge, attitudes, and behaviors to prevent Lyme disease. Overall, 84% of respondents reported that they knew a lot or some about Lyme disease, and 56% felt that they were very or somewhat likely to get Lyme disease in the coming year. During 2002-2004, the percentage of respondents who reported always performing tick checks increased by 7% and the percentage of respondents who reported always using repellents increased by 5%, whereas the percentage of respondents who reported avoiding wooded areas and tucking pants into socks decreased. Overall, 99% of respondents used personal protective behaviors to prevent Lyme disease. In comparison, 65% of respondents reported using environmental tick controls, and increased use of environmental tick controls was observed in only one health district. The majority of respondents were unwilling to spend more than

Persistence of Yersinia pestis in Soil Under Natural Conditions

100 on tick control. These results provide guidance for the development of effective Lyme disease prevention programs by identifying measures most likely to be adopted by residents of Lyme disease endemic communities.

Clinical Recognition and Management of Tularemia in Missouri: A Retrospective Records Review of 121 Cases

As part of a fatal human plague case investigation, we showed that the plague bacterium, Yersinia pestis, can survive for at least 24 days in contaminated soil under natural conditions. These results have implications for defining plague foci, persistence, transmission, and bioremediation after a natural or intentional exposure to Y. pestis.

Primary Pneumonic Plague Contracted from a Mountain Lion Carcass

BACKGROUND Clinical recognition of tularemia is essential for prompt initiation of appropriate antibiotic treatment. Although fluoroquinolones have desirable attributes as a treatment option, limited data on efficacy in the US setting exist. METHODS To define the epidemiology of tularemia in Missouri, and to evaluate practices and outcomes of tularemia management in general, we conducted a detailed retrospective review and analysis of clinical records for patients reported to the state from 2000 to 2007. RESULTS We reviewed records of 121 of 190 patients (64%) reported with tularemia; 79 (65%) were males; the median age was 37 years. Most patients presented with ulceroglandular (37%) and glandular (25%) forms of tularemia, followed by pneumonic (12%), typhoidal (10%), oculoglandular (3%), and oropharyngeal (2%) forms. Most cases (69%) were attributed to tick bites. Median incubation period was 3 days (range, 1-9 days), and patients sought care after a median of 3 days of illness (range, 0-44 days). Systemic disease occurred more commonly in older patients. Patients were prescribed tetracyclines (49%), aminoglycosides (47%), and fluoroquinolones (41%). Nine of 10 patients treated with ciprofloxacin for ≥10 days recovered uneventfully, without accompanying aminoglycosides or tetracyclines. CONCLUSIONS Tularemia is frequently initially misdiagnosed. A thorough exposure history, particularly for tick bites, and awareness of clinical features may prompt clinicians to consider tularemia and facilitate appropriate testing. Promising success with oral fluoroquinolones could provide an acceptable alternative to intravenous aminoglycosides or long courses of tetracyclines where clinically appropriate.

An outbreak of yellow fever with concurrent chikungunya virus transmission in South Kordofan, Sudan, 2005

BACKGROUND Primary pneumonic plague is a rare but often fatal form of Yersinia pestis infection that results from direct inhalation of bacteria and is potentially transmissible from person to person. We describe a case of primary pneumonic plague in a wildlife biologist who was found deceased in his residence 1 week after conducting a necropsy on a mountain lion. METHODS To determine cause of death, a postmortem examination was conducted, and friends and colleagues were interviewed. Physical evidence was reviewed, including specimens from the mountain lion and the biologists medical chart, camera, and computer. Human and animal tissues were submitted for testing. Persons in close contact (within 2 meters) to the biologist after he had developed symptoms were identified and offered chemoprophylaxis. RESULTS The biologist conducted the necropsy in his garage without the use of personal protective equipment. Three days later, he developed fever and hemoptysis and died approximately 6 days after exposure. Gross examination showed consolidation and hemorrhagic fluid in the lungs; no buboes were noted. Plague was diagnosed presumptively by polymerase chain reaction and confirmed by culture. Tissues from the mountain lion tested positive for Y. pestis, and isolates from the biologist and mountain lion were indistinguishable by pulsed-field gel electrophoresis. Among 49 contacts who received chemoprophylaxis, none developed symptoms consistent with plague. CONCLUSIONS The biologist likely acquired pneumonic plague through inhalation of aerosols generated during postmortem examination of an infected mountain lion. Enhanced awareness of zoonotic diseases and appropriate use of personal protective equipment are needed for biologists and others who handle wildlife.

Dog-Associated Risk Factors for Human Plague

From September through December 2005, an outbreak of hemorrhagic fever occurred in South Kordofan, Sudan. Initial laboratory test results identified IgM antibodies against yellow fever (YF) virus in patient samples, and a YF outbreak was declared on 14 November. To control the outbreak, a YF mass vaccination campaign was conducted and vector control implemented in parts of South Kordofan. Surveillance data were obtained from the Sudan Federal Ministry of Health. Clinical information and serum samples were obtained from a subset of patients with illness during the outbreak. Nomads, health personnel and village chiefs were interviewed about the outbreak. Mosquitoes were collected in 11 villages and towns in North and South Kordofan. From 10 September to 9 December 2005 a total of 605 cases of outbreak-related illness were reported, of which 45% were in nomads. Twenty-nine percent of 177 patients seen at clinics in Julud and Abu Jubaiyah had illness consistent with YF. Five of 18 unvaccinated persons with recent illness and 4 of 16 unvaccinated asymptomatic persons had IgM antibodies to YF virus. IgM antibodies to chikungunya virus were detected in five (27%) ill persons and three (19%) asymptomatic persons. These results indicate that both chikungunya and YF occurred during the outbreak.

Bioterrorism-related Inhalational Anthrax in an Elderly Woman, Connecticut, 2001

Plague is a rare but often fatal zoonosis endemic to the western United States. Previous studies have identified contact with pets as a potential risk factor for infection. We conducted a matched case–control study to better define the risks associated with pets at both the household and individual levels. Using a written questionnaire, we surveyed nine surviving plague patients, 12 household members of these patients, and 30 age‐ and neighbourhood‐matched controls about household and individual exposures. Overall, 79% of households had at least one dog, 59% had at least one cat and 33% used flea control, with no significant differences between case and control households. Four (44%) case households reported having a sick dog versus no (0%) control households [matched odds ratio, (mOR) 18.5, 95% confidence interval (CI) 2.3–∞], and four (44%) patients reported sleeping in the same bed with a pet dog versus three (10%) controls (mOR 5.7, 95% CI 1.0–31.6). Within case households with multiple members, two (40%) of five patients slept with their dogs versus none (0%) of 12 healthy family members (P = 0.13). The exposures to cats were not significant. Sleeping in the same bed as a pet dog remained significantly associated with infection in a multivariate logistic regression model (P = 0.046). Our findings suggest that dogs may facilitate the transfer of fleas into the home and that activities with close extended contacts with dogs may increase the risk of plague infection.

Improvement of Disease Prediction and Modeling through the Use of Meteorological Ensembles: Human Plague in Uganda

On November 20, 2001, inhalational anthrax was confirmed in an elderly woman from rural Connecticut. To determine her exposure source, we conducted an extensive epidemiologic, environmental, and laboratory investigation. Molecular subtyping showed that her isolate was indistinguishable from isolates associated with intentionally contaminated letters. No samples from her home or community yielded Bacillus anthracis, and she received no first-class letters from facilities known to have processed intentionally contaminated letters. Environmental sampling in the regional Connecticut postal facility yielded B. anthracis spores from 4 (31%) of 13 sorting machines. One extensively contaminated machine primarily processes bulk mail. A second machine that does final sorting of bulk mail for her zip code yielded B. anthracis on the column of bins for her carrier route. The evidence suggests she was exposed through a cross-contaminated bulk mail letter. Such cross-contamination of letters and postal facilities has implications for managing the response to future B. anthracis–contaminated mailings.

Assessing Human Risk of Exposure to Plague Bacteria in Northwestern Uganda Based on Remotely Sensed Predictors

Climate and weather influence the occurrence, distribution, and incidence of infectious diseases, particularly those caused by vector-borne or zoonotic pathogens. Thus, models based on meteorological data have helped predict when and where human cases are most likely to occur. Such knowledge aids in targeting limited prevention and control resources and may ultimately reduce the burden of diseases. Paradoxically, localities where such models could yield the greatest benefits, such as tropical regions where morbidity and mortality caused by vector-borne diseases is greatest, often lack high-quality in situ local meteorological data. Satellite- and model-based gridded climate datasets can be used to approximate local meteorological conditions in data-sparse regions, however their accuracy varies. Here we investigate how the selection of a particular dataset can influence the outcomes of disease forecasting models. Our model system focuses on plague (Yersinia pestis infection) in the West Nile region of Uganda. The majority of recent human cases have been reported from East Africa and Madagascar, where meteorological observations are sparse and topography yields complex weather patterns. Using an ensemble of meteorological datasets and model-averaging techniques we find that the number of suspected cases in the West Nile region was negatively associated with dry season rainfall (December-February) and positively with rainfall prior to the plague season. We demonstrate that ensembles of available meteorological datasets can be used to quantify climatic uncertainty and minimize its impacts on infectious disease models. These methods are particularly valuable in regions with sparse observational networks and high morbidity and mortality from vector-borne diseases.