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Jay S Keystone

Publications and source records attributed to Jay S Keystone.

18 recordsLinked to original sources
PubMed2006

Spectrum of disease and relation to place of exposure among ill returned travelers.

BACKGROUND: Approximately 8 percent of travelers to the developing world require medical care during or after travel. Current understanding of morbidity profiles among ill returned travelers is based on limited data from the 1980s. METHODS: Thirty GeoSentinel sites, which are specialized travel or tropical-medicine clinics on six continents, contributed clinician-based sentinel surveillance data for 17,353 ill returned travelers. We compared the frequency of occurrence of each diagnosis among travelers returning from six developing regions of the world. RESULTS: Significant regional differences in proportionate morbidity were detected in 16 of 21 broad syndromic categories. Among travelers presenting to GeoSentinel sites, systemic febrile illness without localizing findings occurred disproportionately among those returning from sub-Saharan Africa or Southeast Asia, acute diarrhea among those returning from south central Asia, and dermatologic problems among those returning from the Caribbean or Central or South America. With respect to specific diagnoses, malaria was one of the three most frequent causes of systemic febrile illness among travelers from every region, although travelers from every region except sub-Saharan Africa and Central America had confirmed or probable dengue more frequently than malaria. Among travelers returning from sub-Saharan Africa, rickettsial infection, primarily tick-borne spotted fever, occurred more frequently than typhoid or dengue. Travelers from all regions except Southeast Asia presented with parasite-induced diarrhea more often than with bacterial diarrhea. CONCLUSIONS: When patients present to specialized clinics after travel to the developing world, travel destinations are associated with the probability of the diagnosis of certain diseases. Diagnostic approaches and empiric therapies can be guided by these destination-specific differences.

Adult↗
PubMed2005

Health Risks Associated with Visiting Friends and Relatives in Developing Countries.

An increasingly large proportion of immigrants to developed countries is arriving from less developed countries in Africa, Asia, and Latin America. When these immigrants return to their country of origin to visit friends and relatives, they are at high risk of acquiring tropical infections, compared with other travelers. Immigrants who return to their country of origin to visit friends and relatives (VFRs) are more likely to travel to rural areas for long periods of time, to consume contaminated food and beverages, and to have more prolonged, intimate contact with local populations. As a group, they are less likely to seek pretravel advice or take antimalarial chemoprophylaxis. This article discusses the increased risk of tuberculosis, malaria, food- and waterborne illnesses, hepatitis A, and HIV and other sexually transmitted infections in VFRs.

Journal Article↗
PubMed2005

Travel-related hepatitis B: risk factors and prevention using an accelerated vaccination schedule.

Rates of global travel and tourism are increasing dramatically, especially to regions with medium or high endemicity for hepatitis A and B, such as Asia, Africa, Latin America, and the Middle East. International travelers to these areas should be protected against both hepatitis A and B, regardless of their anticipated length of stay. However, many travelers depart within weeks of planning their trip (too late to complete the accelerated 0-, 1-, 2-month regimen for hepatitis B), and a majority of those traveling depart without being vaccinated. Although extended-stay travelers are at high risk for hepatitis B, short-stay travelers also are at risk. The most commonly encountered risk factors for travel-related hepatitis B are casual sexual activity with a new partner, medical and dental care abroad, and in the expatriate community, adoption of children who are hepatitis B carriers. Although efficacy studies of accelerated schedules for hepatitis B immunization have not been conducted, the results of immunogenicity studies in healthy volunteers who received an accelerated, 3-dose regimen on a 0-,7-, and 21-day schedule suggest that excellent, rapid, and long-term protection will be conferred. More data are needed to assess the efficacy of accelerated schedules in persons aged >40 years and to determine whether a fourth dose of hepatitis B vaccine is needed in all age groups.

Hepatitis B↗
PubMed2005

New strategies for the prevention of malaria in travelers.

Malaria prevention has benefited from many diverse disciplines of research, including epidemiologic monitoring, development of laboratory techniques, assessment of insect repellents, or pharmaceutical innovations. Strategies in all these sectors have been explored in recent years, resulting in improved options to prevent travelers' malaria. The addition of atovaquone-proguanil for malaria chemoprophylaxis and the recommendation of primaquine as primary prophylaxis have been significant advances. Tafenoquine seems promising. Standby treatment recommendations have been refined. Many areas still need better strategies. Problematic areas include chemoprophylaxis for long-term travelers, expatriates, and pregnant women; optimal criteria for terminal prophylaxis; and the prevention of malaria in populations that are least likely to seek pretravel evaluations, such as those visiting friends and relatives in their home countries (VFRs). Finally, research in travel and tropical medicine should continue to focus on additional strategies to confront the ever-widening challenge of drug-resistant malaria.

Animals↗
PubMed2004

Tropical pulmonary eosinophilia: a case series in a setting of nonendemicity.

BACKGROUND: Tropical pulmonary eosinophilia (TPE) is a rare but serious manifestation of infection with the lymphatic filarial parasites Wuchereria bancrofti and Brugia malayi. Although endemicity is limited to the tropical and subtropical regions of Africa, South America, and Asia, immigration and travel practices have led to the diagnosis of TPE in areas of nonendemicity. METHODS: We herein present a case series of all patients with TPE who presented to the Toronto General Hospital during 1990-2003. RESULTS: Seventeen individuals presented with TPE during the study period, and all were of South Asian ancestry. All 17 received an incorrect diagnosis at presentation (median number of consultations before diagnosis, 2), the most frequent of which was asthma (76%). Eosinophil count, serum immunoglobulin E levels, and anti-filarial antibody titers were elevated in all patients. Ten of 14 patients had an abnormal chest radiograph finding, and 11 of 12 patients had abnormal results of pulmonary function tests. CONCLUSIONS: TPE is an important diagnostic consideration in patients with eosinophilia, respiratory symptoms, and history of exposure to this disease. In the untreated individual, TPE can lead to chronic and progressive respiratory compromise and death. Prompt recognition and treatment with diethylcarbamazine is therefore key to minimizing morbidity and mortality.

Adolescent↗
PubMed2004

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

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).

Animals↗
PubMed2004

Travel medicine considerations for North American immigrants visiting friends and relatives.

CONTEXT: In the United States, 10% of the population was born outside of its borders. Immigrants and their children frequently return to visit their homeland, referred to as visiting friends and relatives (VFRs). They account for a disproportionately high volume of international travel. EVIDENCE ACQUISITION: Searches of MEDLINE, World Health Organization, Centers for Disease Control and Prevention, International Society of Travel Medicine, and American Society of Tropical Medicine computerized databases, conference proceedings and abstracts, US Census Bureau, bibliographies of pertinent articles, and travel medicine texts. Priority was given to recent (1996-2003) evidence, addressing VFR travelers. General sources including travel medicine and immigrant health were also used. EVIDENCE SYNTHESIS: Immigrants visiting friends and relatives experience excessive rates of travel-related morbidity and mortality. Lack of pretravel care is common due to patient and clinician barriers to care, preexisting health beliefs, and incomplete childhood vaccinations. Travel patterns increase risk with VFRs traveling to high-risk destinations. Susceptibility to infectious and noninfectious illnesses is often increased because of multiple preexisting medical problems and extremes of age. Infectious diseases differ in etiology and magnitude from those of traditional travelers. For example with malaria, VFRs are frequently prescribed inappropriate prophylaxis or take none at all, have longer stays, spend time in high-risk areas, and do not appropriately adhere to chemoprophylaxis regimens. Effective pretravel health advice, guidelines, and services for this high-risk population are essential. There are already a number of useful and readily available databases that may aid clinicians in providing optimal travel-related preventive and therapeutic care. CONCLUSIONS: Immigrants who are visitors of friends and relatives in other countries account for a high volume of international travelers and are at markedly increased risk of travel-related illness. New strategies are needed to properly address the needs of VFR travelers. Pretravel services should be convenient, accessible, affordable, culturally competent, and if possible, located within clinics serving immigrant populations. Clinicians caring for VFRs should be knowledgeable about their travel-related risks and have access to regularly updated, detailed pretravel health information.

Emigration and Immigration↗
PubMed2004

Malaria.

Malaria is a parasitic infection of global importance. Although relatively uncommon in developed countries, where the disease occurs mainly in travellers who have returned from endemic regions, it remains one of the most prevalent infections of humans worldwide. In endemic regions, malaria is a significant cause of morbidity and mortality and creates enormous social and economic burdens. Current efforts to control malaria focus on reducing attributable morbidity and mortality. Targeted chemoprophylaxis and use of insecticide-treated bed nets have been successful in some endemic areas. For travellers to malaria-endemic regions, personal protective measures and appropriate chemoprophylaxis can significantly reduce the risk of infection. Prompt evaluation of the febrile traveller, a high degree of suspicion of malaria, rapid and accurate diagnosis, and appropriate antimalarial therapy are essential in order to optimize clinical outcomes of infected patients. Additional approaches to malaria control, including genetic manipulation of mosquitoes and malaria vaccines, are areas of ongoing research.

Anemia↗
PubMed2004

Leprosy in Toronto: an analysis of 184 imported cases.

BACKGROUND: Leprosy is a rare but serious mycobacterial infection. Immigration from areas where the disease is endemic has resulted in the importation of leprosy into countries where it is not endemic and where physicians and health care workers have little or no experience in diagnosis and therapy. In this study we characterized leprosy patients seen in a tropical disease unit that manages most of the reported leprosy cases in Canada. METHODS: We reviewed the clinical records of all 184 leprosy patients who were referred to the Tropical Disease Unit at Toronto General Hospital between 1979 and 2002 and abstracted demographic and clinical information. RESULTS: Patients were more likely to be male (122 or 66.3%) and of Indian (44 or 23.9%), Filipino (49 or 26.6%) or Vietnamese (37 or 20.1%) origin. Patients experienced symptoms for a mean of 4.8 years before referral to the Tropical Disease Unit. Most had no family history of leprosy (152/172 or 88.4%). Most patients presented with either borderline tuberculoid (80 or 43.5%) or borderline lepromatous (37 or 20.1%) disease. On average, patients presented with 5.8 skin lesions. Upper- and lower-extremity nerve dysfunction was common at presentation, with up to one-third of patients demonstrating either sensory or motor loss. A significantly greater lag time to presentation was observed in patients who emigrated from low-prevalence regions (p < 0.001). INTERPRETATION: Leprosy is a chronic infectious disease that is associated with serious morbidity if left untreated. Leprosy is uncommon in developed countries, but it is important for physicians to have a high index of suspicion when a foreign-born patient presents with chronic dermatitis and peripheral nerve involvement.

Adult↗
PubMed2004

Leprosy: a primer for Canadian physicians.

Leprosy is a rare but serious infectious disease caused by Mycobacterium leprae. While global prevalence of the disease is decreasing, increasing rates of immigration from countries where leprosy is endemic have led to the recognition of this illness in North America. Classically, leprosy presents as hypopigmented cutaneous macules along with sensory and motor peripheral neuropathies, although the clinical manifestations vary along a disease spectrum. In addition to primary infection, patients may undergo a "reaction," an acute inflammatory response to the mycobacterium, which leads to pain and erythema of skin lesions and dangerous neuritis. Reactions can occur at any time during the course of leprosy, but they tend to be precipitated by treatment. They are a significant cause of impaired quality of life due to marked nerve damage and thus warrant prompt intervention. Although leprosy may have a protracted onset and be difficult to recognize, cure is achievable with appropriate multidrug therapy. Because untreated leprosy can result in permanent, irreversible nerve damage and secondary transmission, early diagnosis and treatment are essential to minimize morbidity.

Diagnosis, Differential↗
PubMed2002

Furuncular myiasis: a simple and rapid method for extraction of intact Dermatobia hominis larvae.

We report a case of furuncular myiasis complicated by Staphylococcus aureus infection and beta-hemolytic streptococcal cellulitis. The Dermatobia hominis larva that caused this lesion could not be extracted using standard methods, including suffocation and application of lateral pressure, and surgery was contraindicated because of cellulitis. The botfly maggot was completely and rapidly extracted with an inexpensive, disposable, commercial venom extractor.

Adult↗
PubMed2002

Serology and eosinophil count in the diagnosis and management of strongyloidiasis in a non-endemic area.

Strongyloidiasis is a chronic infection that may result in significant morbidity; however, diagnosis and management remain problematic. The objective of this study was to 1) evaluate the demographic, clinical, and laboratory features of 76 consecutive individuals who had Strongyloides stercoralis larvae identified in their fecal specimens; 2) determine the sensitivity of the Centers for Disease Control and Prevention (CDC) enzyme immunoassay (EIA) for detecting antibodies to Strongyloides in those with confirmed infection; and 3) assess the serologic responses and changes in eosinophil counts following treatment. Most (96%) cases occurred in immigrants, but some patients had immigrated as long as 40 years earlier. The CDC Strongyloides EIA had a sensitivity of 94.6% (95% confidence interval = 92.0-97.2%) in this patient population with proven infection. Serologic and eosinophil counts decreased after therapy, suggesting that they may be useful markers of treatment success.

Animals↗
PubMedDate not supplied

Prospective analysis of parasitic infections in Canadian travelers and immigrants.

BACKGROUND: International travel is associated with increased risk of vector-borne illnesses, particularly malaria. The objective of this study was to prospectively assess the relative frequency of parasitic diseases in Canadian travelers and to characterize demographic and travel-related predictors of these infections. METHODS: Data on Canadians and new immigrants who crossed international borders and were seen in the Tropical Disease Unit of Toronto General Hospital between November 1997 and June 2003 were prospectively collected and entered into the GeoSentinel Surveillance Network database. RESULTS: Of 3,528 returned Canadian travelers and new immigrants in the database, 1,010 had a parasitic infection diagnosed. Mean age of the 3,528 travelers was 37.3 years, and 42.6% were male. Those diagnosed with parasitic infections were more likely than the remaining cohort to have been traveling for the purpose of immigration (21.1% vs 7.1%, p < 0.001), or visiting friends and relatives (VFR) (17.9% vs 11.8%, p < 0.01). Common parasitic infections included nonhistolytica amebiasis (N= 209), malaria (N= 143), cutaneous larva migrans (N= 105), giardiasis (N= 74), and schistosomiasis (N= 48). CONCLUSIONS: Parasitic infections occurred in 29% of Canadian travelers. New immigrants and VFRs are at increased risk for malaria, as well as protozoal and helminthic infections.

Adult↗