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Featured researches published by Jay S. Keystone.


Clinical Infectious Diseases | 1998

Imported Malaria: Prospective Analysis of Problems in Diagnosis and Management

Kevin C. Kain; Mary Anne Harrington; Shan Tennyson; Jay S. Keystone

Imported malaria is an increasing problem in many countries. The objective of this study was to prospectively evaluate the diagnosis and treatment of imported malaria cases identified by active surveillance. Microscopic diagnosis at the community level was also compared to reference microscopic and blinded molecular diagnostic methods. Most travelers who acquire malaria had sought pretravel advice from a physician; however, only 11% used recommended chemoprophylaxis and only 17% used insect protection measures. The diagnosis of malaria was initially missed in 59% of cases. Community-based microscopic diagnosis provided incorrect species identification in 64% of cases. After presentation, the average delay before treatment was 7.6 days for falciparum malaria and 5.1 days for vivax malaria. Overall, 7.5% of Plasmodium falciparum-infected patients developed severe malaria, and in 11% of all cases therapy failed. Patients who present to a center without expertise in tropical medicine receive suboptimal treatment. Improvements in recognition, diagnosis, and treatment of malaria are essential to prevent morbidity and death among travelers.


Clinical Infectious Diseases | 2007

Fever in returned travelers: results from the GeoSentinel surveillance network.

Mary E. Wilson; Leisa H. Weld; Andrea K. Boggild; Jay S. Keystone; Kevin C. Kain; Frank von Sonnenburg; Eli Schwartz

BACKGROUND Fever is a marker of potentially serious illness in returned travelers. Information about causes of fever, organized by geographic area and traveler characteristics, can facilitate timely, appropriate treatment and preventive measures. METHODS Using a large, multicenter database, we assessed how frequently fever is cited as a chief reason for seeking medical care among ill returned travelers. We defined the causes of fever by place of exposure and traveler characteristics. RESULTS Of 24,920 returned travelers seen at a GeoSentinel clinic from March 1997 through March 2006, 6957 (28%) cited fever as a chief reason for seeking care. Of patients with fever, 26% were hospitalized (compared with 3% who did not have fever); 35% had a febrile systemic illness, 15% had a febrile diarrheal disease, and 14% had fever and a respiratory illness. Malaria was the most common specific etiologic diagnosis, found in 21% of ill returned travelers with fever. Causes of fever varied by region visited and by time of presentation after travel. Ill travelers who returned from sub-Saharan Africa, south-central Asia, and Latin America whose reason for travel was visiting friends and relatives were more likely to experience fever than any other group. More than 17% of travelers with fever had a vaccine-preventable infection or falciparum malaria, which is preventable with chemoprophylaxis. Malaria accounted for 33% of the 12 deaths among febrile travelers. CONCLUSIONS Fever is common in ill returned travelers and often results in hospitalization. The time of presentation after travel provides important clues toward establishing a diagnosis. Preventing and promptly treating malaria, providing appropriate vaccines, and identifying ways to reach travelers whose purpose for travel is visiting friends and relatives in advance of travel can reduce the burden of travel-related illness.


Annals of Internal Medicine | 2013

GeoSentinel surveillance of illness in returned travelers, 2007-2011.

Karin Leder; Joseph Torresi; Michael Libman; Jakob P. Cramer; Francesco Castelli; Patricia Schlagenhauf; Annelies Wilder-Smith; Mary E. Wilson; Jay S. Keystone; Eli Schwartz; Elizabeth D. Barnett; Frank von Sonnenburg; John S. Brownstein; Allen C. Cheng; Mark J. Sotir; Douglas H. Esposito; David O. Freedman

BACKGROUND International travel continues to increase, particularly to Asia and Africa. Clinicians are increasingly likely to be consulted for advice before travel or by ill returned travelers. OBJECTIVE To describe typical diseases in returned travelers according to region, travel reason, and patient demographic characteristics; describe the pattern of low-frequency travel-associated diseases; and refine key messages for care before and after travel. DESIGN Descriptive, using GeoSentinel records. SETTING 53 tropical or travel disease units in 24 countries. PATIENTS 42 173 ill returned travelers seen between 2007 and 2011. MEASUREMENTS Frequencies of demographic characteristics, regions visited, and illnesses reported. RESULTS Asia (32.6%) and sub-Saharan Africa (26.7%) were the most common regions where illnesses were acquired. Three quarters of travel-related illness was due to gastrointestinal (34.0%), febrile (23.3%), and dermatologic (19.5%) diseases. Only 40.5% of all ill travelers reported pretravel medical visits. The relative frequency of many diseases varied with both travel destination and reason for travel, with travelers visiting friends and relatives in their country of origin having both a disproportionately high burden of serious febrile illness and very low rates of advice before travel (18.3%). Life-threatening diseases, such as Plasmodium falciparum malaria, melioidosis, and African trypanosomiasis, were reported. LIMITATIONS Sentinel surveillance data collected by specialist clinics do not reflect healthy returning travelers or those with mild or self-limited illness. Data cannot be used to infer quantitative risk for illness. CONCLUSION Many illnesses may have been preventable with appropriate advice, chemoprophylaxis, or vaccination. Clinicians can use these 5-year GeoSentinel data to help tailor more efficient pretravel preparation strategies and evaluate possible differential diagnoses of ill returned travelers according to destination and reason for travel. PRIMARY FUNDING SOURCE Centers for Disease Control and Prevention.


Clinical Infectious Diseases | 2006

The Practice of Travel Medicine: Guidelines by the Infectious Diseases Society of America

David R. Hill; Charles D. Ericsson; Richard D. Pearson; Jay S. Keystone; David O. Freedman; Phyllis E. Kozarsky; Herbert L. DuPont; Frank J. Bia; Philip R. Fischer; Edward T. Ryan

David R. Hill, Charles D. Ericsson, Richard D. Pearson, Jay S. Keystone, David O. Freedman, Phyllis E. Kozarsky, Herbert L. DuPont, Frank J. Bia, Philip R. Fischer, and Edward T. Ryan National Travel Health Network and Centre and Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, England; Department of Medicine, University of Toronto, and Center for Travel and Tropical Medicine, Toronto General Hospital, Toronto, Ontario, Canada; Department of Internal Medicine, Clinical Infectious Diseases, University of Texas Medical School at Houston, Department of Internal Medicine, St. Luke’s Hospital, and Center for Infectious Diseases, University of Texas at Houston School of Public Health, and Department of Medicine, Baylor College of Medicine, Houston, Texas; Departments of Medicine and Pathology, Division of Infectious Diseases and International Health, University of Virginia School of Medicine, Charlottesville, Virginia; Departments of Medicine and Epidemiology, Division of Geographic Medicine, University of Alabama at Birmingham, Birmingham; Department of Medicine, Infectious Diseases, Emory University School of Medicine, and 16 Division of Global Migration and Quarantine, Centers for Disease Control and Prevention, Atlanta, Georgia; Department of Medicine and Laboratory Medicine, Yale Medical School, New Haven, Connecticut; Department of Pediatrics, Division of General Pediatric and Adolescent Medicine, Mayo Clinic College of Medicine, and Mayo Eugenio Litta Children’s Hospital, Mayo Clinic, Rochester, Minnesota; and Department of Medicine, Division of Infectious Diseases, Harvard Medical School, Harvard School of Public Health, and Tropical and Geographic Medicine Center, Massachusetts General Hospital, Boston, Massachusetts


Canadian Medical Association Journal | 2004

Complicated and fatal Strongyloides infection in Canadians: risk factors, diagnosis and management

Sue Lim; Kevin Katz; Sigmund Krajden; Milan Fuksa; Jay S. Keystone; Kevin C. Kain

STRONGYLOIDIASIS, WHICH IS CAUSED by the nematode Strongyloides stercoralis, is a common and persistent infection, particularly in developing countries. In the setting of compromised cellular immunity, it can result in fulminant dissemination with case-fatality rates of over 70%. The majority of new Canadian immigrants come from countries where Strongyloides is highly endemic; therefore, the burden of Strongyloides may be underappreciated in Canada. Because early diagnosis and therapy can have a marked impact on disease outcome, screening for this infection should be considered mandatory for patients who have a history of travel or residence in a disease-endemic area and risk factors for disseminated disease (e.g., corticosteroid use and human T-lymphotropic virus type I infection).


JAMA Internal Medicine | 1995

Imported Malaria: Clinical Presentation and Examination of Symptomatic Travelers

James E. Svenson; J. Dick MacLean; Theresa W. Gyorkos; Jay S. Keystone

BACKGROUND The diagnosis of malaria in nonendemic countries presents a continuing challenge. Increasing physician awareness of the variability in its clinical presentation will improve clinical management and health outcomes. METHODS Charts of patients in whom malaria was diagnosed at two hospital-based tropical disease centers between September 1, 1980, and December 31, 1991, were reviewed. RESULTS Of a total of 482 cases, 182 were caused by Plasmodium falciparum and 246 by Plasmodium vivax. Fifty-two patients with P falciparum malaria were hospitalized; 13 were classified as having severe falciparum malaria. Nineteen patients with P vivax malaria required hospitalization. The only death was caused by P vivax. Chemoprophylaxis was used by, or prescribed for, 46% of patients; however, of these, only half were compliant in taking their medication. Eighty-seven percent of patients with falciparum malaria presented within 6 weeks of return from travel to an endemic area. One third of patients with P vivax malaria presented more than 6 months after travel. The average time between onset of symptoms and physician contact was 6.7 days. Diagnosis was often delayed in those who sought care outside the referral center. Almost all patients had a history of fever, but only half were febrile at presentation. Presenting symptoms and signs were non-specific. Fifty percent of patients were thrombocytopenic. Other laboratory abnormalities were mild. CONCLUSIONS Since the presentation of malaria is vague and nonspecific, the diagnosis should be considered in any appropriately symptomatic patient with a history of travel to a malaria-endemic area, and appropriate testing should be done. Up-to-date information on chemoprophylaxis should be provided to all travelers to malaria-endemic regions.


Archives of Dermatology | 1993

Creeping Eruption: A Review of Clinical Presentation and Management of 60 Cases Presenting to a Tropical Disease Unit

Herbert D. Davies; Peter Sakuls; Jay S. Keystone

BACKGROUND AND DESIGN Cutaneous larva migrans is an infection with a larval nematode, most frequently by dog or cat hookworms. It has a characteristic presentation that is easily recognizable. We reviewed the charts of 60 patients with cutaneous larva migrans who presented to the Tropical Disease Unit, Toronto (Ontario) Hospital, during a 6-year period. RESULTS Ninety-five percent of the patients were Canadians who had recently returned from the tropics or subtropics, notably the Caribbean. Almost all patients had a linear or serpiginous, very pruritic larval track. Topical thiabendazole was efficacious in 52 (98%) of 53 patients treated. Albendazole cured six (88%) of seven patients treated. Because of adverse effects, oral thiabendazole and liquid nitrogen were not utilized. CONCLUSION We conclude that topical thiabendazole and oral albendazole are very effective and safe modalities for the treatment of cutaneous larva migrans.


Emerging Infectious Diseases | 2008

Seasonality, Annual Trends, and Characteristics of Dengue among Ill Returned Travelers, 1997–2006

Eli Schwartz; Leisa H. Weld; Annelies Wilder-Smith; Frank von Sonnenburg; Jay S. Keystone; Kevin C. Kain; Joseph Torresi; David O. Freedman

Atypical patterns may indicate onset of epidemic activity.


Emerging Infectious Diseases | 2009

Multicenter GeoSentinel Analysis of Rickettsial Diseases in International Travelers, 1996–2008

Mogens Jensenius; Xiaohong M. Davis; Frank von Sonnenburg; Eli Schwartz; Jay S. Keystone; Karin Leder; Rogelio López-Vélez; Eric Caumes; Jakob P. Cramer; Lin Chen; Philippe Parola

Spotted fever group rickettsiosis acquired in sub-Saharan Africa was the most common rickettsial disease observed.


International Journal of Infectious Diseases | 2008

Dermatologic conditions of the ill returned traveler: an analysis from the GeoSentinel Surveillance Network.

Edith R. Lederman; Leisa H. Weld; Iqbal Elyazar; Frank von Sonnenburg; Louis Loutan; Eli Schwartz; Jay S. Keystone

BACKGROUND Skin disorders are common in travelers. Knowledge of the relative frequency of post-travel-related skin disorders, including their geographic and demographic risk factors, will allow for effective pre-travel counseling, as well as improved post-travel diagnosis and therapeutic intervention. METHODS We performed a retrospective study using anonymous patient demographic, clinical, and travel-related data from the GeoSentinel Surveillance Network clinics from January 1997 through February 2006. The characteristics of these travelers and their itineraries were analyzed using SAS 9.0 statistical software. RESULTS A skin-related diagnosis was reported for 4594 patients (18% of all patients seen in a GeoSentinel clinic after travel). The most common skin-related diagnoses were cutaneous larva migrans (CLM), insect bites including superinfected bites, skin abscess, and allergic reaction (38% of all diagnoses). Arthropod-related skin diseases accounted for 31% of all skin diagnoses. Ill travelers who visited countries in the Caribbean experienced the highest proportionate morbidity due to dermatologic conditions. Pediatric travelers had significantly more dog bites and CLM and fewer insect bites compared with their adult counterparts; geriatric travelers had proportionately more spotted fever and cellulitis. CONCLUSIONS Clinicians seeing patients post-travel should be alert to classic travel-related skin diseases such as CLM as well as more mundane entities such as pyodermas and allergic reactions. To prevent and manage skin-related morbidity during travel, international travelers should avoid direct contact with sand, soil, and animals and carry a travel kit including insect repellent, topical antifungals, and corticosteroids and, in the case of extended and/or remote travel, an oral antibiotic with ample coverage for pyogenic organisms.

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Kevin C. Kain

Toronto General Hospital

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David O. Freedman

University of Alabama at Birmingham

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Kathryn N. Suh

Children's Hospital of Eastern Ontario

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