Emily S. Jentes

The revised global yellow fever risk map and recommendations for vaccination, 2010: consensus of the Informal WHO Working Group on Geographic Risk for Yellow Fever

The changing epidemiology of yellow fever and continued reports of rare but serious adverse events associated with yellow fever vaccine have drawn attention to the need to revisit criteria for the designation of areas with risk for yellow fever virus activity, and to revise the vaccine recommendations for international travel. WHO convened a working group of international experts to review factors important for the transmission of yellow fever virus and country-specific yellow fever information, to establish criteria for additions to or removal from the list of countries with risk for yellow fever virus transmission, to update yellow fever risk maps, and to revise the recommendations for vaccination for international travel. This report details the recommendations made by the working group about criteria for the designation of risk and specific changes to the classification of areas with risk for transmission of yellow fever virus.

Pre-Travel Health Care of Immigrants Returning Home to Visit Friends and Relatives

Immigrants returning home to visit friends and relatives (VFR travelers) are at higher risk of travel-associated illness than other international travelers. We evaluated 3,707 VFR and 17,507 non-VFR travelers seen for pre-travel consultation in Global TravEpiNet during 2009–2011; all were traveling to resource-poor destinations. VFR travelers more commonly visited urban destinations than non-VFR travelers (42% versus 30%, P < 0.0001); 54% of VFR travelers were female, and 18% of VFR travelers were under 6 years old. VFR travelers sought health advice closer to their departure than non-VFR travelers (median days before departure was 17 versus 26, P < 0.0001). In multivariable analysis, being a VFR traveler was an independent predictor of declining a recommended vaccine. Missed opportunities for vaccination could be addressed by improving the timing of pre-travel health care and increasing the acceptance of vaccines. Making pre-travel health care available in primary care settings may be one step to this goal.

International travel by persons with medical comorbidities: understanding risks and providing advice.

OBJECTIVE To describe the medical conditions, travel plans, counseling, and medications prescribed for high-risk international travelers. PATIENTS AND METHODS This cross-sectional study was conducted from March 1, 2008, through July 31, 2010, in 5 clinics in the greater Boston area. We assessed all travelers seen for pretravel care and compared demographic characteristics, travel plans, pretravel counseling, and interventions for healthy and high-risk travelers (as defined by medical history or pregnancy). RESULTS Of 15,440 travelers, 2769 (17.9%) were high-risk; 644 of 2769 (23.3%) were immunocompromised travelers, 2056 (74.3%) had medical comorbidities, and 69 (2.5%) were pregnant women. The median age of high-risk travelers was 47 years compared with 32 years for healthy travelers (P=.0001). High-risk travelers visited the clinic a median of 25 days (range, 10-44 days) before departure. Overall, 2562 (93.9%) of high-risk travelers visited countries with medium or high risk of typhoid fever, 2340 (85.7%) visited malaria-risk countries, and 624 (22.8%) visited yellow fever-endemic countries. Of travelers to yellow fever-endemic countries, 8 of 23 (34.8%) pregnant women and 64 of 144 (44.4%) immunocompromised travelers received yellow fever vaccine. Of eligible high-risk travelers, 11 of 76 (14.5%) received a pneumococcal vaccine, 213 of 640 (33.3%) influenza vaccine, and 956 of 2681 (35.7%) either tetanus-diphtheria or tetanus-diphtheria-pertussis vaccine. CONCLUSION High-risk travelers made up nearly 20% of patients in these travel clinics, and they mostly traveled to destinations with malaria and typhoid risk. For health care professionals caring for travelers with underlying medical problems, providing appropriate travel counseling and making vaccine decisions, such as for yellow fever, are complex. Travelers with complicated medical histories may warrant evaluation by an experienced travel medicine specialist.

Acute Arboviral Infections in Guinea, West Africa, 2006

Acute febrile illnesses comprise the majority of the human disease burden in sub-Saharan Africa. We hypothesized that arboviruses comprised a considerable proportion of undiagnosed febrile illnesses in Guinea and sought to determine the frequency of arboviral disease in two hospitals there. Using a standard case definition, 47 suspected cases were detected in approximately 4 months. Immunoglobulin M antibody capture enzyme-linked immunosorbent assays and plaque-reduction neutralization assays revealed that 63% (30/47) of patients were infected with arboviruses, including 11 West Nile, 2 yellow fever, 1 dengue, 8 chikungunya, and 5 Tahyna infections. Except for yellow fever, these are the first reported cases of human disease from these viruses in Guinea and the first reported cases of symptomatic Tahyna infection in Africa. These results strongly suggest that arboviruses circulate and are common causes of disease in Guinea. Improving surveillance and laboratory capacity for arbovirus diagnoses will be integral to understanding the burden posed by these agents in the region.

Knowledge, attitudes, and practices of US practitioners who provide pre-travel advice.

BACKGROUND As international travel increases, many health care professionals are being asked to provide pre-travel advice. We designed an anonymous web-based survey to assess the extent to which primary care providers (PCPs) provide travel medicine advice and how their understanding and delivery of itinerary-specific advice and management compare with that of travel medicine specialists. METHODS We surveyed randomly selected US PCPs registered in the Pri-Med Institute (now pmiCME) database and US travel medicine specialists from the International Society of Travel Medicine (ISTM), American Society of Tropical Medicine and Hygiene (ASTMH), and Centers for Disease Control and Prevention (CDC) yellow fever (YF) vaccine provider mailing lists. SAS software (SAS Institute, Cary, NC, USA) was used for all analyses. RESULTS Of 14,932 e-mails sent to valid e-mail addresses, 902 yielded complete or partially completed surveys (6.0% response rate). Eighty percent of respondents personally provided pre-travel advice (95% of travel medicine specialists versus 73% of PCPs). About two thirds of PCPs (68%) providing pre-travel consultations saw <50 travelers per year whereas 30% of travel medicine specialists saw <50 travelers per year. More travel medicine specialists (59%) than PCPs (18%) saw >500 travelers per year. Familiarity with travel-specific vaccines (YF, Japanese encephalitis) and provision of written educational materials increased as volume of travelers increased. Familiarity with antimalarial side effects and malaria resistance patterns, and knowledge scores based on brief pre-travel scenarios were higher in travel medicine specialists, ASTMH or ISTM certificate holders, and respondents who saw more pre-travel patients. CONCLUSIONS Many PCP survey participants provided pre-travel advice, but most saw few travelers. Volume of travelers and holding an ASTMH or ISTM certificate had the greatest influence on knowledge of travel medicine and provision of appropriate advice and recommendations. Creating easily accessible travel medicine education programs for US providers from a wide range of disciplines is needed to improve the management of travelers.

A cluster of dengue cases in American missionaries returning from Haiti, 2010.

Dengue is an acute febrile illness caused by four mosquito-borne dengue viruses (DENV-1 to -4) that are endemic throughout the tropics. After returning from a 1-week missionary trip to Haiti in October of 2010, 5 of 28 (18%) travelers were hospitalized for dengue-like illness. All travelers were invited to submit serum specimens and complete questionnaires on pre-travel preparations, mosquito avoidance practices, and activities during travel. DENV infection was confirmed in seven (25%) travelers, including all travelers that were hospitalized. Viral sequencing revealed closest homology to a 2007 DENV-1 isolate from the Dominican Republic. Although most (88%) travelers had a pre-travel healthcare visit, only one-quarter knew that dengue is a risk in Haiti, and one-quarter regularly used insect repellent. This report confirms recent DENV transmission in Haiti. Travelers to DENV-endemic areas should receive dengue education during pre-travel health consultations, follow mosquito avoidance recommendations, and seek medical care for febrile illness during or after travel.

Health challenges of young travelers visiting friends and relatives compared with those traveling for other purposes.

Background: The study objective was to assess differences in demographics and travel health challenges between youths ⩽18 years old traveling internationally to visit friends and relatives (VFRs) compared with those traveling for other purposes (non-VFR). Methods: The Boston Area Travel Medicine Network consists of 5 clinics collecting anonymous data from international pretravel consultations. Data on all travelers ⩽18 years of age seen between January 2008 and July 2010 were used. VFRs were compared with non-VFRs on demographics, primary language, trip characteristics, travel vaccinations administered, malaria prophylaxis and antidiarrheal medications prescribed. Results: Thirty-five percent (610/1731) listed VFR as their purpose of travel. Almost half of VFRs were <5 (46%) years old compared with <5% of non-VFRs. Thirty percent of US-born VFRs with foreign-born parents were ⩽2 years compared with 4% of foreign-born VFR children and 3% of US-born VFRs with US-born parents. More VFRs than non-VFRs planned travel to countries that were yellow fever holoendemic, had malaria risk and were high-risk for typhoid (44% versus 20%, 39% versus 12%, 25% versus 15%, P < 0.01). VFRs were less likely than non-VFRs to be prescribed atovaquone-proguanil (adjusted prevalence ratio = 0.57, confidence interval = 0.44–0.72) and to have had an antidiarrheal medication prescribed (adjusted prevalence ratio = 0.68, confidence interval = 0.60–0.75). Conclusions: To reduce travel-related morbidity, healthcare providers should be prepared to give travel advice to parents of VFR infants and children, particularly those US-born VFRs with foreign-born parents, regarding antimalarial and antidiarrheal medications and preventing yellow fever, malaria and typhoid.

Use of Japanese Encephalitis Vaccine in US Travel Medicine Practices in Global TravEpiNet

Few data regarding the use of Japanese encephalitis (JE) vaccine in clinical practice are available. We identified 711 travelers at higher risk and 7,578 travelers at lower risk for JE who were seen at US Global TravEpiNet sites from September of 2009 to August of 2012. Higher-risk travelers were younger than lower-risk travelers (median age = 29 years versus 40 years, P < 0.001). Over 70% of higher-risk travelers neither received JE vaccine during the clinic visit nor had been previously vaccinated. In the majority of these instances, clinicians determined that the JE vaccine was not indicated for the higher-risk traveler, which contradicts current recommendations of the Advisory Committee on Immunization Practices. Better understanding is needed of the clinical decision-making regarding JE vaccine in US travel medicine practices.

Pre-Travel Health Preparation of Pediatric International Travelers: Analysis From the Global TravEpiNet Consortium

BACKGROUND Children frequently travel internationally. Health-related data on such children are limited. We sought to investigate the demographics, health characteristics, and preventive interventions of outbound US international pediatric travelers. METHODS We analyzed data from 32 099 travelers presenting for pre-travel healthcare at the Global TravEpiNet (GTEN), a national consortium of 19 travel clinics, from January 1, 2009 to June 6, 2012. RESULTS A total of 3332 (10%) of all GTEN travelers were children (<18 years of age). These children traveled mostly for leisure (36%) or to visit friends or relatives (VFR) (36%). Most popular destination regions were Africa (41%), Southeast Asia (16%), Central America (16%), and the Caribbean (16%). Compared with children traveling for leisure, VFR children were more likely to present <14 days before departure for pre-travel consultation (44% vs 28%), intended to travel for 28 days or longer (70% vs 22%), and to travel to Africa (62% vs 32%). Nearly half of the pediatric travelers (46%) received at least 1 routine vaccine, and most (83%) received at least 1 travel-related vaccine. Parents or guardians of one third of the children (30%) refused at least 1 recommended travel-related vaccine. Most pediatric travelers visiting a malaria-endemic country (72%) received a prescription for malaria chemoprophylaxis. CONCLUSIONS Ten percent of travelers seeking pre-travel healthcare at GTEN sites are children. VFR-travel, pre-travel consultation close to time of departure, and refusal of recommended vaccines may place children at risk for travel-associated illness. Strategies to engage pediatric travelers in timely, pre-travel care and improve acceptance of pre-travel healthcare interventions are needed.

Immunocompromised Travelers: Demographic Characteristics, Travel Destinations, and Pretravel Health Care from the U.S. Global TravEpiNet Consortium

An increasing number of immunocompromised individuals are pursuing international travel, and a better understanding of their international travel patterns and pretravel health care is needed. We evaluated the clinical features, itineraries, and pretravel health care of 486 immunocompromised international travelers seen at Global TravEpiNet sites from January 2009 to June 2012. We used bivariate analyses and logistic regressions using random intercept models to compare demographic and travel characteristics, vaccines administered, and medications prescribed for immunocompromised travelers versus 30,702 immunocompetent travelers. Immunocompromised travelers pursued itineraries that were largely similar to those of immunocompetent travelers, with nearly one-third of such travelers visiting countries with low human development indices. Biological agents, including tumor necrosis factor blockers, were commonly used immunosuppressive medications among immunocompromised travelers. A strong collaboration between travel-medicine specialists, primary care doctors, and specialist physicians is needed to prepare immunocompromised people for international travel. Incorporating routine questioning and planning regarding travel into the primary care visits of immunocompromised people may be useful.