Lin H. Chen

Threat of Dengue to Blood Safety in Dengue-Endemic Countries

Modeling the risk for transmission of this disease is quantified by blood transfusions.

Dengue and chikungunya infections in travelers

Purpose of review Dengue and chikungunya are arboviruses that have caused major outbreaks and infected travelers, and both can be associated with fever and rash. We review the recent epidemiology of dengue and chikungunya infections and discuss their clinical presentations, diagnosis, treatment, and prevention. We highlight the findings in travelers. Recent findings Globally dengue is one of the most common infections associated with travel, and incidence has increased in the Americas in recent years, especially in Brazil. Chikungunya has caused dramatic outbreaks in the Indian Ocean islands since 2004, and has spread to south and south-east Asia. Dengue virus and chikungunya virus also possess the potential to cause autochthonous transmission in temperate regions of developed countries due to the presence of the vector mosquito, Aedes albopictus. Such an outbreak (chikungunya infection) did occur in 2007 in Italy. A mutation in chikungunya virus (A226V) appears to improve virus survival in Aedes albopictus and also increase its virulence. Summary The findings assist in differentiating dengue and chikungunya from other acute febrile illnesses and from each other. The findings also illustrate potential outbreaks in nonendemic countries, important toward developing control and prevention strategies.

Illness in long-term travelers visiting GeoSentinel clinics

Length of travel appears to be associated with health risks.

Transmission of Dengue Virus without a Mosquito Vector: Nosocomial Mucocutaneous Transmission and Other Routes of Transmission

We report a case of dengue fever in a Boston-area health care worker with no recent history of travel but with mucocutaneous exposure to infected blood from a febrile traveler who had recently returned from Peru. Serologic tests confirmed acute dengue virus infection in both the traveler and the health care worker. We believe that this is the first documented case of dengue virus transmission via the mucocutaneous route. We present case reports and review other ways that dengue virus has been transmitted without a mosquito vector.

Sex and Gender Differences in Travel-Associated Disease

BACKGROUND No systematic studies exist on sex and gender differences across a broad range of travel-associated diseases. METHODS Travel and tropical medicine GeoSentinel clinics worldwide contributed prospective, standardized data on 58,908 patients with travel-associated illness to a central database from 1 March 1997 through 31 October 2007. We evaluated sex and gender differences in health outcomes and in demographic characteristics. Statistical significance for crude analysis of dichotomous variables was determined using chi2 tests with calculation of odds ratios (ORs) and 95% confidence intervals (CIs). The main outcome measure was proportionate morbidity of specific diagnoses in men and women. The analyses were adjusted for age, travel duration, pretravel encounter, reason for travel, and geographical region visited. RESULTS We found statistically significant (P < .001) differences in morbidity by sex. Women are proportionately more likely than men to present with acute diarrhea (OR, 1.13; 95% CI, 1.09-1.38), chronic diarrhea (OR, 1.28; 95% CI, 1.19-1.37), irritable bowel syndrome (OR, 1.39; 95% CI, 1.24-1.57), upper respiratory tract infection (OR, 1.23; 95% CI, 1.14-1.33); urinary tract infection (OR, 4.01; 95% CI, 3.34-4.71), psychological stressors (OR, 1.3; 95% CI, 1.14-1.48), oral and dental conditions, or adverse reactions to medication. Women are proportionately less likely to have febrile illnesses (OR, 0.15; 95% CI, 0.10-0.21); vector-borne diseases, such as malaria (OR, 0.46; 95% CI, 0.41-0.51), leishmaniasis, or rickettsioses (OR, 0.57; 95% CI, 0.43-0.74); sexually transmitted infections (OR, 0.68; 95% CI 0.58-0.81); viral hepatitis (OR, 0.34; 95% CI, 0.21-0.54); or noninfectious problems, including cardiovascular disease, acute mountain sickness, and frostbite. Women are statistically significantly more likely to obtain pretravel advice (OR, 1.28; 95% CI, 1.23-1.32), and ill female travelers are less likely than ill male travelers to be hospitalized (OR, 0.45; 95% CI, 0.42-0.49). CONCLUSIONS Men and women present with different profiles of travel-related morbidity. Preventive travel medicine and future travel medicine research need to address gender-specific intervention strategies and differential susceptibility to disease.

The role of the traveler in emerging infections and magnitude of travel.

Travel and trade have grown immensely. Travelers interact with people and microbes during their journeys, and can introduce infectious agents to new areas and populations. Studying illnesses in travelers is a source of knowledge into diseases of resource-poor regions and the control of these diseases. Travel-associated illnesses also serve to detect emerging infections.

The Globalization of Healthcare: Implications of Medical Tourism for the Infectious Disease Clinician

Knowledge of medical tourism is critical in incorporating a global perspective into clinical care. Medical histories must include details of travel and medical care abroad. Infection control issues are critical, as patients may be colonized or infected with unusual organisms.

Preventing Infectious Diseases during and after International Adoption

From 1989 to 2002, U.S. families adopted more than 167 000 children internationally (1). In 2002, U.S. citizens adopted 20 099 children from 20 countries; by comparison, 7093 foreign-born children were adopted in 1990 (1). During the past decade, the countries from which most children have been adopted have changed. In 1989, children were adopted most frequently from Korea, Colombia, India, the Philippines, and Chile (1). By 2002, only 1 of these countries (Korea) remained in the list of top 5 countries; China, Russia, Guatemala, and the Ukraine replaced the other 4 countries (Figure). This shift can be associated with a change in disease epidemiology in adopted children. The outbreaks of severe acute respiratory syndrome (SARS) illustrate the dynamic relationship of infectious diseases and travelers and the need to have up-to-date information. Figure. Trend in the number of adopted children from the most common countries of origin Health status and medical management of internationally adopted children have been described by experts in the field (2-6). Most recommend pretravel advice for parents traveling to bring home their adopted children. Parents who travel to bring home newly adopted children are at risk for both travel-related illness and disease organisms that may be carried by their new child. In addition, other family members who do not travel may also be at risk because of subsequent contact with the child. Thus, preparation for adoptive families must expand to include nontraveling family members and risks from the adopted child that may be unrelated to travel. We review the data on health status of internationally adopted children, describe potential risks for disease transmission from these children to their adoptive families, and recommend appropriate general pretravel counseling of adoptive families for the primary care physician. For details on the literature search used to identify the data, see the Appendix. This paper is not a comprehensive review of travel medicine. Health Status of Internationally Adopted Children Health status of internationally adopted children has been described in reports summarizing findings in children from many countries and in papers focusing on children from a single country. Hostetter and colleagues (2) identified important medical conditions in 57% of 293 internationally adopted children; 81% of these unsuspected diagnoses were made by obtaining a specific panel of screening tests. Initially evaluating internationally adopted children for infectious diseases has evolved to include a detailed history and physical examination and laboratory screening by using a consistent panel of tests for diseases present in countries from which children are adopted. Current recommendations include hepatitis B surface antigen, surface antibody, and core antibody; HIV testing; Mantoux test; stool examination for ova and parasites; rapid plasma reagin for syphilis; complete blood count with erythrocyte indices; and hepatitis C virus testing (Table 1). Table 2 summarizes the infectious diseases found in internationally adopted children. Table 1. Testing Recommended by the American Academy of Pediatrics in Screening Internationally Adopted Children for Infectious Diseases Table 2. Infection or Evidence of Past Infection Found in the Screening of Internationally Adopted Children Infectious Diseases in Adopted Children and Potential for Transmission Tuberculosis Positive tuberculin test results are more common in internationally adopted children than in children of similar age born in the United States (2). Tuberculosis is highly prevalent in many countries from which adopted children originate, including China, Russia, Korea, Vietnam, India, Guatemala, and Ukraine (11). Higher rates of positive skin test results occur because of more frequent exposure to tuberculosis and because internationally adopted children are more likely to have received Bacille CalmetteGurin vaccine. Case rates of tuberculosis in internationally adopted children are at least 4 to 6 times higher than those among individuals born in the United States, and immigrants remain at risk for developing active tuberculosis for many years after arriving in the United States (11). Tuberculin skin test results are positive in 3% to 5% of internationally adopted children in most studies (2, 7-9), but rates as high as 19% have been reported (10). Although latent tuberculosis is the most common form of tuberculosis identified by screening, active tuberculosis spread in the community has also occurred. In 1998, tuberculosis organisms were transmitted from a 9-year old child from the Republic of the Marshall Islands to his female guardian in North Dakota (12). Bilateral cavitary pulmonary tuberculosis was diagnosed only after his guardian developed tuberculous arthritis and osteomyelitis. Of the 276 individuals in contact with the child who were tested, 56 individuals (20%) had a positive Mantoux test result ( 10 mm), and 118 individuals received preventive antituberculosis therapy. Preventing transmission of tuberculosis organisms from adopted children rests on screening and timely diagnosis in adopted children. Because treating asymptomatic individuals who have positive tuberculin skin test results does not prevent all disease, a high index of suspicion must be maintained for tuberculosis in the years after adoption. Hepatitis B Hepatitis B surface antigen was identified in 2% to 20% of internationally adopted children, indicating a potential to infect the childrens contacts (2, 7-10). The highest rate was noted in adopted children from Romania (7) and was consistent with the serologic data from Romanian orphanages, where 35% of the children had hepatitis B surface antigen (13). Hepatitis B virus infection is also highly prevalent in many other countries where internationally adopted children originate, including China, Korea, Vietnam, and Kazakhstan (14). Hepatitis B surface antibody was found in 14% to 53% of the adopted children, reflecting past infection or, in some cases, immunization. One report noted the diagnosis of chronic hepatitis B in adopted Romanian children who had been presented as uninfected before adoption (15). Household transmission of hepatitis B is well described (16, 17). In a report of hepatitis B virus transmission from Asian children to their adoptive U.S. families, 9% of 77 family members exposed to children carrying hepatitis B virus had evidence of past or present infection, compared with 2% of 232 family members without such exposure (18). In a series of 65 patients with chronic hepatitis B seen in the Department of Pediatrics at Universit catholique de Louvain, Brussels, Belgium, from 1989 to 1993 (19), 31 patients were adopted, most of whom were from Romania and Asia. Seven of 11 (64%) nonvaccinated parents had acute hepatitis B that was attributed to the adopted child. Three additional parents had hepatitis B surface or core antibodies. One teacher, one grandfather, and one 16-year-old friend had acute hepatitis B. Only 4 of the infected individuals had recognized contact with blood or body fluids of the carrier child. Hepatitis A Symptomatic hepatitis A virus infection rarely occurs in internationally adopted children, and most experts do not screen for hepatitis A. However, hepatitis A is highly prevalent in most countries from which children are adopted (14). One series (2) mentions 2 children with hepatitis A virus infection, but it is unclear whether the children had current infection or evidence of past infection. Transmitting hepatitis A virus from asymptomatic children to their adoptive family members is possible. In 1 case, an adoptive parent who traveled to Russia to adopt a 15-month-old child developed hepatitis A more than 2 months after return (20). The asymptomatic child had hepatitis A IgM and was presumed to have been incubating hepatitis A when he left Russia. Pertussis Pertussis occurs worldwide but is a greater risk for people who are underimmunized or people with waning immunity. Pertussis was diagnosed by culture in a 10-month-old adopted infant 2 days after arrival in the United States from Russia. The adoptive family and many passengers on the flight from Russia were exposed (21). The Centers for Disease Control and Prevention collaborated with the U.S. embassy, adoption agencies, visa applicants, medical clinics in Moscow, and the airline to identify and notify exposed persons. The child had no record of immunization against pertussis. Measles, Mumps, and Rubella Measles is a risk in many countries, and outbreaks have occurred in some European and Asian countries (22). Cases of measles and mumps have been reported in internationally adopted children (23). In 2001, fourteen U.S. measles cases were identified in children recently adopted from China and their family members and close contacts in 8 states. In 13 of these cases, patients were probably exposed to measles in China during visits to an orphanage or during medical screening or travel. The outbreak highlighted the large number of persons potentially exposed during the adoption process: the adoptive families, representatives of adoption agencies traveling with the families and meeting them on return, staff at the U.S. Consulate, and passengers and crew members of international and domestic flights. Ten cases were reported in recently adopted children 9 to 12 months of age. Other cases included 2 U.S.-born adoptive mothers, 1 U.S.-born caretaker who spent a week in the household with an adopted child with measles, and 1 sibling of an adopted child (24). In the United States, measles vaccine is almost always administered as combined measles, mumps, and rubella vaccines. In contrast, some countries immunize children with monovalent measles or combined measles and rubella vaccines; hence, children may lack mumps or rubella coverage, or both. Ideally, adoptive families should be immune to mumps and rubella, as well as

Illness in Travelers Returned From Brazil: The GeoSentinel Experience and Implications for the 2014 FIFA World Cup and the 2016 Summer Olympics

Common problems in ill returned travelers to Brazil are dermatologic conditions, diarrhea, and febrile illnesses, especially dengue. Knowledge of potential risks can help clinicians to advise travelers attending large events in Brazil and to care for those who become ill.

Expatriates ill after travel: Results from the Geosentinel Surveillance Network

BackgroundExpatriates are a distinct population at unique risk for health problems related to their travel exposure.MethodsWe analyzed GeoSentinel data comparing ill returned expatriates with other travelers for demographics, travel characteristics, and proportionate morbidity (PM) for travel-related illness.ResultsOur study included 2,883 expatriates and 11,910 non-expatriates who visited GeoSentinel clinics ill after travel. Expatriates were more likely to be male, do volunteer work, be long-stay travelers (>6 months), and have sought pre-travel advice. Compared to non-expatriates, expatriates returning from Africa had higher proportionate morbidity (PM) for malaria, filariasis, schistosomiasis, and hepatitis E; expatriates from the Asia-Pacific region had higher PM for strongyloidiasis, depression, and anxiety; expatriates returning from Latin America had higher PM for mononucleosis and ingestion-related infections (giardiasis, brucellosis). Expatriates returning from all three regions had higher PM for latent TB, amebiasis, and gastrointestinal infections (other than acute diarrhea) compared to non-expatriates. When the data were stratified by travel reason, business expatriates had higher PM for febrile systemic illness (malaria and dengue) and vaccine-preventable infections (hepatitis A), and volunteer expatriates had higher PM for parasitic infections. Expatriates overall had higher adjusted odds ratios for latent TB and lower odds ratios for acute diarrhea and dermatologic illness.ConclusionsIll returned expatriates differ from other travelers in travel characteristics and proportionate morbidity for specific diseases, based on the region of exposure and travel reason. They are more likely to present with more serious illness.