Pretravel Health Preparation of International Travelers: Results From the Boston Area Travel Medicine Network.

OBJECTIVE: To inform future interventions for advising travelers. PATIENTS AND METHODS: We prospectively collected data on travelers seen at the Boston Area Travel Medicine Network, a Boston area research collaboration of 5 travel medicine clinics. Data from 15,440 travelers were collected from March 1, 2008, through July 31, 2010. We compared traveler and trip characteristics and differences in demographic characteristics and travel plans across the 5 clinics, including an analysis of pretravel preparations for certain high-risk destinations. RESULTS: More than half of the 15,440 travelers were female (8730 [56.5]), and 72.4% (10,528 of 14,545) were white; the median age was 34 years, and 29.4% of travelers (3077 of 10,483) were seen less than 2 weeks before their departure date. Substantial variation in racial background, purpose of travel, and destination risk existed across the 5 clinics. For example, the proportion of travelers visiting friends and relatives ranged from 7.6% (184 of 2436) to 39.0% (1029 of 2639) (18.7% [2876 of 15,360] overall), and the percentage of travelers to areas with malaria risk ranged from 23.7% (333 of 1403) to 52.0% (1306 of 2512). Although most clinics were likely to have prescribed certain vaccines for high-risk destinations (eg, yellow fever for Ghana travel), there was wide variability in influenza vaccine use for China travel. CONCLUSION: Substantial differences in clinic populations can occur within a single metropolitan area, highlighting why individual physicians and travel clinics need to understand the specific needs of the travelers they serve in addition to general travel medicine.

Immunity to hepatitis A and hepatitis B in Indian and Chinese immigrants seen in a travel clinic in Massachusetts, United States.

Immigrants to the United States from developing countries have a higher probability of previous infection with hepatitis A virus (HAV) and/or hepatitis B virus in their countries of origin. Prior knowledge of hepatitis A and B seroprevalence in this population may aid in determining the need for pretravel immunizations when these individuals travel to endemic regions. We conducted a retrospective analysis of hepatitis A and B serologies in a travel clinic population (from March 1999 through September 2002) to determine the seroprevalence in our predominantly highly educated foreign-born subjects. All our patients who had immigrated from China and India and who were older than 60 years (born on or before 1940) were immune to hepatitis A. The Indian and Chinese subjects who were anti-HAV positive were also significantly older than the anti-HAV negative group. In addition, in our Indian study group, the hepatitis A-seropositive individuals first left India at a significantly older age than the hepatitis A-seronegative group (mean age 22.7 years vs 11.4 years, p < 0.05). Our small sample size of Chinese subjects may not have permitted a statistically significant difference to be detected for hepatitis A seroprevalence and age at departure from their country of origin. These results have helped tailor our recommendations for pretravel immunizations for our groups of foreign-born individuals planning to visit endemic areas. Individuals born in China or India on or before 1940 are likely to have preexisting antibody to hepatitis A and probably do not need the vaccine when they travel. Younger individuals may elect to have a hepatitis A antibody titer checked before getting the vaccine.

Self-reported illness among Boston-area international travelers: A prospective study.

BACKGROUND: The Boston Area Travel Medicine Network surveyed travelers on travel-related health problems. METHODS: Travelers were recruited 2009-2011 during pre-travel consultation at three clinics. The investigation included pre-travel data, weekly during-travel diaries, and a post-travel questionnaire. We analyzed demographics, trip characteristics, health problems experienced, and assessed the relationship between influenza vaccination, influenza prevention advice, and respiratory symptoms. RESULTS: Of 987 enrolled travelers, 628 (64%) completed all surveys, of which 400 (64%) reported health problems during and/or after travel; median trip duration was 12 days. Diarrhea affected the most people during travel (172) while runny/stuffy nose affected the most people after travel (95). Of those with health problems during travel, 25% stopped or altered plans; 1% were hospitalized. After travel, 21% stopped planned activities, 23% sought physician or other health advice; one traveler was hospitalized. Travelers who received influenza vaccination and influenza prevention advice had lower rates of respiratory symptoms than those that received influenza prevention advice alone (18% vs 28%, P = 0.03). CONCLUSIONS: A large proportion of Boston-area travelers reported health problems despite pre-travel consultation, resulting in inconveniences. The combination of influenza prevention advice and influenza immunization was associated with fewer respiratory symptoms than those who received influenza prevention advice alone.

Dengue Virus Seroconversion in Travelers to Dengue-Endemic Areas.

We conducted a prospective study to measure dengue virus (DENV) antibody seroconversion in travelers to dengue-endemic areas. Travelers seen in the Boston Area Travel Medicine Network planning to visit dengue-endemic countries for ≥ 2 weeks were enrolled from 2009 to 2010. Pre- and post-travel blood samples and questionnaires were collected. Post-travel sera were tested for anti-DENV IgG by indirect IgG enzyme-linked immunosorbent assay (ELISA) and anti-DENV IgM by capture IgM ELISA. Participants with positive post-travel anti-DENV IgG or IgM were tested for pre-travel anti-DENV IgG and IgM; they were excluded from the seroconversion calculation if either pre-travel anti-DENV IgG or IgM were positive. Paired sera and questionnaires were collected for 62% (589/955) of enrolled travelers. Most participants were 19-64 years of age, female, and white. The most common purposes of travel were tourism and visiting friends and relatives; most trips were to Asia or Africa. Median length of travel was 21 days. DENV antibody seroconversion by either anti-DENV IgM or IgG ELISA was 2.9-6.8%; lower range percent excluded potential false-positive anti-DENV IgG due to receipt of yellow fever or Japanese encephalitis vaccines at enrollment; upper range percent excluded proven false-positive anti-DENV IgM. Eighteen percent of those with seroconversion reported dengue-like symptoms. Seroconversion was documented for travel to Africa as well as countries and regions known to be highly dengue endemic (India, Brazil, southeast Asia). Given widespread risk of dengue, travel medicine counseling should include information on risk of dengue in endemic areas and advice on preventing insect bites and seeking prompt medical attention for febrile illness.

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.

Prevalence of dengue virus infection in US travelers who have lived in or traveled to dengue-endemic countries.

BACKGROUND: Dengue virus (DENV) infections may occur in travelers. OBJECTIVES: To determine prevalence of anti-DENV IgG antibody in travelers who lived in or visited dengue-endemic countries and to describe risk factors and characteristics associated with infection and subsequent anti-DENV IgG antibody presence. METHODS: Participants were enrolled from travel clinics of the Boston Area Travel Medicine Network from August 2008 through June 2009. Demographic information, trip duration, travel history, and a blood sample were collected. Serum samples were tested for anti-DENV IgG antibody by indirect IgG enzyme-linked immunosorbent assay (ELISA), and antibody-mediated virus neutralization by plaque reduction neutralization test (PRNT) for anti-DENV IgG antibody-positive and selected negative samples. Participants were stratified into group 1: born in dengue-endemic countries; group 2: born in nonendemic countries but lived continuously for ≥1 year in a dengue-endemic country; group 3: born in nonendemic countries and traveled to a dengue-endemic country for ≥2 weeks but <1 year. RESULTS: Six hundred travelers were enrolled. Anti-DENV IgG antibody was identified in 113 (19%) when tested by ELISA (51% in group 1, 40% in group 2, and 6.9% in group 3) and in 71 (12%) by PRNT (42% primary monotypic and 58% heterotypic reactive responses). Sensitivity and specificity of the ELISA based on PRNT results were 85% to 100% and 79% to 94%, assuming up to 15% misclassification of ELISA negative results. Presence of anti-DENV IgG antibody by ELISA was associated with years lived in dengue-endemic countries and birthplace in the Caribbean for group 1, receipt of Japanese encephalitis vaccine in group 3, and self-reported history of dengue in all three groups. CONCLUSIONS: Nineteen percent of participants who were born, lived in, or traveled to dengue-endemic countries had anti-DENV IgG antibody by ELISA; 12% had antibodies by PRNT, 85% of whom had no history of dengue. Presence of DENV antibodies was associated with years lived in dengue-endemic countries and self-reported history of dengue.

Acceptability of hypothetical dengue vaccines among travelers.

BACKGROUND: Dengue viruses have spread widely in recent decades and cause tens of millions of infections mostly in tropical and subtropical areas. Vaccine candidates are being studied aggressively and may be ready for licensure soon. METHODS: We surveyed patients with past or upcoming travel to dengue-endemic countries to assess rates and determinants of acceptance for four hypothetical dengue vaccines with variable efficacy and adverse event (AE) profiles. Acceptance ratios were calculated for vaccines with varied efficacy and AE risk. RESULTS: Acceptance of the four hypothetical vaccines ranged from 54% for the vaccine with lower efficacy and serious AE risk to 95% for the vaccine with higher efficacy and minor AE risk. Given equal efficacy, vaccines with lower AE risk were better accepted than those with higher AE risk; given equivalent AE risk, vaccines with higher efficacy were better accepted than those with lower efficacy. History of Japanese encephalitis vaccination was associated with lower vaccine acceptance for one of the hypothetical vaccines. US-born travelers were more likely than non-US born travelers to accept a vaccine with 75% efficacy and a risk of minor AEs (p = 0.003). Compared with North American-born travelers, Asian- and African-born travelers were less likely to accept both vaccines with 75% efficacy. CONCLUSIONS: Most travelers would accept a safe and efficacious dengue vaccine if one were available. Travelers valued fewer potential AEs over increased vaccine efficacy.

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.

Short report: A calcified Taenia solium granuloma associated with recurrent perilesional edema causing refractory seizures: histopathological features.

We describe the first detailed histological description of an excised calcified Taenia solium granuloma from a patient who developed recurrent seizures associated with perilesional edema surrounding a calcified cysticercus (PEC). The capsule, around a degenerated cysticercus, contained marked mononuclear infiltrates that extended to adjacent brain, which showed marked astrocytosis, microgliosis, and inflammatory perivascular infiltrates. The presence of large numbers of mononuclear cells supports an inflammatory cause of PEC. Immunosuppression or anti-inflammatory measures may be able to treat and prevent PEC and recurrent seizures.

Leprosy and the peripheral nervous system: basic and clinical aspects.

Leprosy is one of the most common causes of nontraumatic peripheral neuropathy in the developing world. The causative agent, Mycobacterium leprae, has a predilection for Schwann cells, where the organism multiplies unimpeded by organism-specific host immunity, resulting in destruction of myelin, secondary inflammatory changes, and destruction of the nerve architecture. The cardinal diagnostic features of leprosy are anesthetic skin lesions, neuropathy, and positive skin smears for the bacilli. However, patients may rarely present without skin lesions in pure neuritic leprosy. Electrodiagnostic findings early in the disease reveal demyelinating features, such as slowing of conduction velocity and prolongation of latencies, but as the disease progresses secondary axonal damage commonly ensues. Electrodiagnostic studies are also useful to monitor for toxicity secondary to therapy, particularly thalidomide-associated neuropathy. Nerve biopsy of a sensory cutaneous nerve is sometimes essential to confirm a diagnosis of leprosy. Significant advances in understanding of the pathogenesis, mapping of the genome, and other advances in molecular biology may result in better preventive and therapeutic modalities, and the goal of eradicating leprosy as a global problem may yet be realized.

Dengue fever mimicking plasma cell leukemia.

Extreme plasmacytosis in peripheral blood is a rare finding most often associated with plasma cell leukemia but rarely with other malignancies, infectious diseases, or drug reactions. We report the case of a 40-year-old man who was a US expatriate working and traveling in East Asia. He presented with complaints of fever, myalgia, headache, vomiting, and diarrhea of 3 days' duration. An initial evaluation revealed elevated liver function tests, thrombocytopenia (68 x 10(3)/microL), and a white blood cell count of 5.8 x 10(3)/microL with 19% plasma cells (1100/microL), 9% abnormal plasmacytoid lymphocytes (520/microL), 37% polymorphonuclear leukocytes, 3% band forms, 27% lymphocytes, 4% monocytes, and 1% eosinophils. An extensive evaluation was performed, including infectious disease serologies, a bone marrow biopsy, and flow cytometry. During the course of 3 days, his symptoms and hematologic findings improved dramatically. Serologic results were reactive for dengue (immunoglobulin M [IgM] positive, reciprocal IgG titer, 655 360), consistent with a secondary infection of unknown serotype. He remains well 4 years later. To our knowledge, plasmacytosis to this degree has not been described in dengue fever, but atypical lymphocytosis is common. In patients from dengue-endemic areas, even extreme plasmacytosis should be assessed to determine whether it is transient and related to an acute illness before proceeding to an extensive evaluation.