Elizabeth D. Barnett

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

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.

Adverse event reports following yellow fever vaccination.

Yellow fever (YF) vaccine has been used for prevention of YF since 1937 with over 500 million doses administered. However, rare reports of severe adverse events following vaccination have raised concerns about the vaccines safety. We reviewed reports of adverse events following YF vaccination reported to the U.S. Vaccine Adverse Event Reporting System (VAERS) from 2000 to 2006. We used estimates of age and sex distribution of administered doses obtained from a 2006 survey of authorized vaccine providers to calculate age- and sex-specific reporting rates of all serious adverse events (SAE), anaphylaxis, YF vaccine-associated neurotropic disease, and YF vaccine-associated viscerotropic disease. Reporting rates of SAEs were substantially higher in males and in persons aged > or =60 years. These findings reinforce the generally acceptable safety profile of YF vaccine, but highlight the importance of physician and traveler education regarding the risks and benefits of YF vaccination, particularly for travelers > or =60 years of age. Vaccination should be limited to persons traveling to areas where the risk of YF is expected to exceed the risk of serious adverse events after vaccination, or if not medically contraindicated, where national regulations require proof of vaccination to prevent introduction of YF.

Yellow Fever: Epidemiology and Prevention

Yellow fever continues to occur in regions of Africa and South America, despite the availability of effective vaccines. Recently, some cases of severe neurologic disease and multiorgan system disease have been described in individuals who received yellow fever vaccine. These events have focused attention on the need to define criteria for judicious use of yellow fever vaccine and to describe the spectrum of adverse events that may be associated with yellow fever vaccine. Describing host factors that would increase risk of these events and identifying potential treatment modalities for yellow fever and yellow fever vaccine-associated adverse events are subjects of intense investigation.

Vaccine preventable diseases in returned international travelers: results from the GeoSentinel Surveillance Network.

Vaccine preventable diseases (VPDs) threaten international travelers, but little is known about their epidemiology in this group. We analyzed records of 37,542 ill returned travelers entered into the GeoSentinel Surveillance Network database. Among 580 (1.5%) with VPDs, common diagnoses included enteric fever (n=276), acute viral hepatitis (n=148), and influenza (n=70). Factors associated with S. typhi included VFR travel (p<0.016) to South Central Asia (p<0.001). Business travel was associated with influenza (p<0.001), and longer travel with hepatitis A virus (p=0.02). 29% of those with VPDs had pre-travel consultations. At least 55% of those with VPDs were managed as inpatients, compared to 9.5% of those with non-VPDs. Three deaths occurred; one each due to pneumococcal meningitis, S. typhi, and rabies. VPDs are significant contributors to morbidity and potential mortality in travelers. High rates of hospitalization make them an attractive target for pre-travel intervention.

Illness in Children After International Travel: Analysis From the GeoSentinel Surveillance Network

OBJECTIVE: By using a large, multicenter database, we investigated the characteristics and morbidities of 1591 children returning from 218 global destinations and presenting for care in 19 countries. METHODS: Data reported to the GeoSentinel Surveillance Network between January 1997 and November 2007 were analyzed, to assess demographic features, travel characteristics, and clinical diagnoses of ill pediatric travelers. Data were compared between children and adults and among 3 pediatric age groups (0–5 years, 6–11 years, and 12–17 years). RESULTS: Children were predominantly tourist travelers returning from Asia, sub-Saharan Africa, or Latin America. Compared with adults, children disproportionately presented within 7 days after return, required hospitalization, lacked pretravel health advice, and had traveled for the purpose of visiting friends and relatives. Diarrhea (28%), dermatologic conditions (25%), systemic febrile illnesses (23%), and respiratory disorders (11%) accounted for the majority of diagnoses reported for children. No fatalities were reported. Diarrhea occurred disproportionately among children after exposure to the Middle East/North Africa, dermatologic conditions after exposure to Latin America, systemic febrile illnesses after exposure to sub-Saharan Africa or Asia, and respiratory disorders after exposure to Europe or North America. The proportionate morbidity rates of travel-associated diseases differed among the pediatric age groups and between children and adults. CONCLUSIONS: The health care utilization patterns before and after travel and the profiles of travel-associated health problems differed between children and adults. Health professionals providing pretravel advice need to consider destination- and age-specific susceptibility to travel-related morbidities and develop prevention strategies accordingly.

Diagnostic Evaluation of Newly Arrived Asymptomatic Refugees with Eosinophilia

BACKGROUND Refugees may arrive for resettlement with asymptomatic parasitic infections, and eosinophilia may be the only clue to the presence of infection. Our aim was to determine the prevalence of eosinophilia and develop a standardized approach to the evaluation of asymptomatic refugees with eosinophilia. METHODS We reviewed the medical records of refugees seen from October 1998 through May 2002 at Boston Medical Center. Data examined included age, country of origin, absolute eosinophil count, results of stool ova and parasite testing, and results of serological testing for Strongyloides stercoralis, Schistosoma species, and filaria. RESULTS Eosinophilia--defined as an absolute eosinophil count of >or=450 cells/microL--was present in 266 (12%) of 2224 refugees. Patients with eosinophilia ranged in age from 2 months to 81 years and had arrived from Africa, Eastern Europe, Southeast Asia, South America, the Caribbean, and the Middle East. Absolute eosinophil counts ranged from 450 to 3224 cells/microL. Pathogens were identified in stool samples of 76 (29%) of 265 patients. Serological testing for S. stercoralis, Schistosoma species, and/or filaria was done for 120 (45%) of 266 patients. Results of serological testing were positive for S. stercoralis in 45 (39%) of 115 patients, for Schistosoma species in 15 (22%) of 67 patients, and for filaria in 18 (51%) of 35 patients. Serological evidence of parasitic infection was seen at all levels of eosinophilia and in patients with and without pathogens identified in their stool samples. CONCLUSIONS Systematic evaluation for parasites in asymptomatic, newly arrived refugees with eosinophilia should include stool ova and parasite examination, serological examination for S. stercoralis for all patients, and serological examination for Schistosoma species and filaria in patients from regions where these organisms are endemic.

The Problem of Resistant Bacteria for the Management of Acute Otitis Media

The emergence of pneumococci resistant to penicillin has prompted an examination of the role of resistant organisms in the response to treatment for AOM. At this time, antibiotic-resistant organisms play a small role in the number of episodes of AOM that do not respond to initial therapy. Amoxicillin remains the drug of choice for treatment of AOM. For children who do not respond, assessment of clinical status is important. Children who are well-appearing may respond to a beta-lactamase stable oral agent. Children who are ill may require tympanostomy and presumptive therapy for infection due to resistant organisms.

Infectious Disease Screening for Refugees Resettled in the United States

Refugees resettling in the United States carry a significant burden of infectious diseases as a result of exposures in their countries of origin and the circumstances of their migration. Overseas screening is required before entry, but it incompletely assesses infectious diseases in refugees. Domestic health assessment has the potential to provide more comprehensive assessment for infectious diseases. Screening protocols ideally should test for tuberculosis, hepatitis B, and intestinal and other parasites and should include mechanisms for providing or updating immunizations. Testing for other infectious diseases, including malaria, hepatitis C, human immunodeficiency virus, and sexually transmitted diseases, can be performed on the basis of clinical signs and symptoms. This article reviews the current status of overseas and domestic health screening for refugees, infectious disease burdens, and future goals for health assessment of refugees and other immigrants.

Filariasis in Travelers Presenting to the GeoSentinel Surveillance Network

Background As international travel increases, there is rising exposure to many pathogens not traditionally encountered in the resource-rich countries of the world. Filarial infections, a great problem throughout the tropics and subtropics, are relatively rare among travelers even to filaria-endemic regions of the world. The GeoSentinel Surveillance Network, a global network of medicine/travel clinics, was established in 1995 to detect morbidity trends among travelers. Principal Findings We examined data from the GeoSentinel database to determine demographic and travel characteristics associated with filaria acquisition and to understand the differences in clinical presentation between nonendemic visitors and those born in filaria-endemic regions of the world. Filarial infections comprised 0.62% (n = 271) of all medical conditions reported to the GeoSentinel Network from travelers; 37% of patients were diagnosed with Onchocerca volvulus, 25% were infected with Loa loa, and another 25% were diagnosed with Wuchereria bancrofti. Most infections were reported from immigrants and from those immigrants returning to their county of origin (those visiting friends and relatives); the majority of filarial infections were acquired in sub-Saharan Africa. Among the patients who were natives of filaria-nonendemic regions, 70.6% acquired their filarial infection with exposure greater than 1 month. Moreover, nonendemic visitors to filaria-endemic regions were more likely to present to GeoSentinel sites with clinically symptomatic conditions compared with those who had lifelong exposure. Significance Codifying the filarial infections presenting to the GeoSentinel Surveillance Network has provided insights into the clinical differences seen among filaria-infected expatriates and those from endemic regions and demonstrated that O. volvulus infection can be acquired with short-term travel.

Interferon-γ Release Assays for Diagnosis of Tuberculosis Infection and Disease in Children

Tuberculosis (TB) remains an important problem among children in the United States and throughout the world. Although diagnosis and treatment of infection with Mycobacterium tuberculosis (also referred to as latent tuberculosis infection [LTBI] or TB infection) remain the lynchpins of TB prevention, there is no diagnostic reference standard for LTBI. The tuberculin skin test (TST) has many limitations, including difficulty in administration and interpretation, the need for a return visit by the patient, and false-positive results caused by significant cross-reaction with Mycobacterium bovis–bacille Calmette-Guérin (BCG) vaccines and many nontuberculous mycobacteria. Interferon-γ release assays (IGRAs) are blood tests that measure ex vivo T-lymphocyte release of interferon-γ after stimulation by antigens specific for M tuberculosis. Because these antigens are not found on M bovis–BCG or most nontuberculous mycobacteria, IGRAs are more specific tests than the TST, yielding fewer false-positive results. However, IGRAs have little advantage over the TST in sensitivity, and both methods have reduced sensitivity in immunocompromised children, including children with severe TB disease. Both methods have a higher positive predictive value when applied to children with risk factors for LTBI. Unfortunately, neither method distinguishes between TB infection and TB disease. The objective of this technical report is to review what IGRAs are most useful for: (1) increasing test specificity in children who have received a BCG vaccine and may have a false-positive TST result; (2) using with the TST to increase sensitivity for finding LTBI in patients at high risk of developing progression from LTBI to disease; and (3) helping to diagnose TB disease.