Characteristics of schistosomiasis in travelers reported to the GeoSentinel Surveillance Network 1997-2008

Among ill returned travelers to Schistosoma-endemic areas reported to the GeoSentinel Surveillance Network over a decade 410 schistosomiasis diagnoses were identified: 102 Schistosoma mansoni, 88 S. haematobium, 7 S. japonicum, and 213 Schistosoma unknown human species. A total of 83% were acquired in Africa. Unlike previous large case series, individuals born in endemic areas were excluded. Controlling for age and sex, those traveling for missionary or volunteer work, or as expatriates were more likely to be diagnosed with schistosomiasis. Sixty-three percent of those with schistosomiasis presented within six months of travel. Those seen early more often presented with fever and respiratory symptoms compared with those who presented later. One-third of patients with schistosomiasis were asymptomatic at diagnosis. Half of those examined for schistosomiasis were diagnosed with infection. Screening for schistosomiasis should be encouraged for all potentially exposed travelers and especially for missionaries, volunteers, and expatriates.

Seasonality, annual trends, and characteristics of dengue among ill returned travelers, 1997-2006

Atypical patterns may indicate onset of epidemic activity.

We examined seasonality and annual trends for dengue cases among 522 returned travelers reported to the international GeoSentinel Surveillance Network. Dengue cases showed region-specific peaks for Southeast Asia (June, September), South Central Asia (October), South America (March), and the Caribbean (August, October). Travel-related dengue exhibited annual oscillations with several epidemics occurring during the study period. In Southeast Asia, annual proportionate morbidity increased from 50 dengue cases per 1,000 ill returned travelers in nonepidemic years to an average of 159 cases per 1,000 travelers during epidemic years. Dengue can thus be added to the list of diseases for which pretravel advice should include information on relative risk according to season. Also, dengue cases detected at atypical times in sentinel travelers may inform the international community of the onset of epidemic activity in specific areas.

Health risks in travelers to China: the GeoSentinel experience and implications for the 2008 Beijing Olympics

Selected data collected for travelers to China from 1998 through November 2007 by the GeoSentinel Surveillance Network were used to provide an evidence base for prioritizing recommendations for Olympic and other future travelers to China. Respiratory illness and injuries were common among patients seen during their travel; acute diarrhea and dog bites were common among those seen after travel. Tropical and parasitic diseases were rare. Pre-travel consultation for China travelers should be individualized according to these findings.

Safety and reactogenicity profile of an adjuvanted H5N1 pandemic candidate vaccine in adults within a phase III safety trial

A multicentre, randomized, phase III clinical trial in 5071 healthy adults was conducted to evaluate the safety and reactogenicity of a 15 microg HA dose of a candidate oil-in-water emulsion-based adjuvant system (AS)-adjuvanted split-virion H5N1 (AS-H5N1) vaccine compared to a licensed seasonal influenza vaccine, Fluarix.(1) Stringent criteria were used to evaluate adverse events and reactogenicity profile. Overall, 96.7% of the 5071 vaccinated subjects completed the study. Significantly more participants in the AS-H5N1 vaccine group reported general or local adverse events. Pain was the most common symptom in both treatment groups. Less than 1% of subjects withdrew from the study due to adverse events and no withdrawals were due to serious adverse events related to vaccination. The safety and reactogenicity profile of the AS-H5N1 candidate vaccine can be considered clinically acceptable in the context of its use against pandemic influenza.

Dermatologic conditions of the ill returned traveler: an analysis from the GeoSentinel Surveillance Network

BACKGROUND

Skin disorders are common in travelers. Knowledge of the relative frequency of post-travel-related skin disorders, including their geographic and demographic risk factors, will allow for effective pre-travel counseling, as well as improved post-travel diagnosis and therapeutic intervention.

METHODS

We performed a retrospective study using anonymous patient demographic, clinical, and travel-related data from the GeoSentinel Surveillance Network clinics from January 1997 through February 2006. The characteristics of these travelers and their itineraries were analyzed using SAS 9.0 statistical software.

RESULTS

A skin-related diagnosis was reported for 4594 patients (18% of all patients seen in a GeoSentinel clinic after travel). The most common skin-related diagnoses were cutaneous larva migrans (CLM), insect bites including superinfected bites, skin abscess, and allergic reaction (38% of all diagnoses). Arthropod-related skin diseases accounted for 31% of all skin diagnoses. Ill travelers who visited countries in the Caribbean experienced the highest proportionate morbidity due to dermatologic conditions. Pediatric travelers had significantly more dog bites and CLM and fewer insect bites compared with their adult counterparts; geriatric travelers had proportionately more spotted fever and cellulitis.

CONCLUSIONS

Clinicians seeing patients post-travel should be alert to classic travel-related skin diseases such as CLM as well as more mundane entities such as pyodermas and allergic reactions. To prevent and manage skin-related morbidity during travel, international travelers should avoid direct contact with sand, soil, and animals and carry a travel kit including insect repellent, topical antifungals, and corticosteroids and, in the case of extended and/or remote travel, an oral antibiotic with ample coverage for pyogenic organisms.

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.

Fever in returned travelers: results from the GeoSentinel Surveillance Network

BACKGROUND

Fever is a marker of potentially serious illness in returned travelers. Information about causes of fever, organized by geographic area and traveler characteristics, can facilitate timely, appropriate treatment and preventive measures.

METHODS

Using a large, multicenter database, we assessed how frequently fever is cited as a chief reason for seeking medical care among ill returned travelers. We defined the causes of fever by place of exposure and traveler characteristics.

RESULTS

Of 24,920 returned travelers seen at a GeoSentinel clinic from March 1997 through March 2006, 6957 (28%) cited fever as a chief reason for seeking care. Of patients with fever, 26% were hospitalized (compared with 3% who did not have fever); 35% had a febrile systemic illness, 15% had a febrile diarrheal disease, and 14% had fever and a respiratory illness. Malaria was the most common specific etiologic diagnosis, found in 21% of ill returned travelers with fever. Causes of fever varied by region visited and by time of presentation after travel. Ill travelers who returned from sub-Saharan Africa, south-central Asia, and Latin America whose reason for travel was visiting friends and relatives were more likely to experience fever than any other group. More than 17% of travelers with fever had a vaccine-preventable infection or falciparum malaria, which is preventable with chemoprophylaxis. Malaria accounted for 33% of the 12 deaths among febrile travelers.

CONCLUSIONS

Fever is common in ill returned travelers and often results in hospitalization. The time of presentation after travel provides important clues toward establishing a diagnosis. Preventing and promptly treating malaria, providing appropriate vaccines, and identifying ways to reach travelers whose purpose for travel is visiting friends and relatives in advance of travel can reduce the burden of travel-related illness.

Illness in Travelers Visiting Friends and Relatives: A Review of the GeoSentinel Surveillance Network

Travelers returning to their country of origin to visit friends and relatives (VFRs) have increased risk of travel-related health problems. We examined GeoSentinel data to compare travel characteristics and illnesses acquired by 3 groups of travelers to low-income countries: VFRs who had originally been immigrants (immigrant VFRs), VFRs who had not originally been immigrants (traveler VFRs), and tourist travelers. Immigrant VFRs were predominantly male, had a higher mean age, and disproportionately required treatment as inpatients. Only 16% of immigrant VFRs sought pretravel medical advice. Proportionately more immigrant VFRs visited sub-Saharan Africa and traveled for >30 days, whereas tourist travelers more often traveled to Asia. Systemic febrile illnesses (including malaria), nondiarrheal intestinal parasitic infections, respiratory syndromes, tuberculosis, and sexually transmitted diseases were more commonly diagnosed among immigrant VFRs, whereas acute diarrhea was comparatively less frequent. Immigrant VFRs and traveler VFRs had different demographic characteristics and types of travel-related illnesses. A greater proportion of immigrant VFRs presented with serious, potentially preventable travel-related illnesses than did tourist travelers.

Hepatitis A/B vaccination of adults over 40 years old: Comparison of three vaccine regimens and effect of influencing factors

Challenged by contrasting data on low immune responses in the elderly with a combined hepatitis A/B vaccine, a randomised, controlled study was conducted to assess the immunogenicity of three hepatitis A and B vaccination regimens (group 1: combined hepatitis A/B vaccine Twinrix [GSK]; group 2: co-administered hepatitis A vaccine, Havrix [GSK]+hepatitis B vaccine Engerix -B [GSK], group 3: co-administered hepatitis A vaccine, Vaqta [Sanofi-Pasteur MSD]+hepatitis B vaccine HB VAX PRO [Sanofi-Pasteur MSD]) and the effect of influencing factors in subjects >40 years. On completion of the full vaccination course, anti-HBs seroprotection (SP) rates were 92, 80 and 71% in groups 1, 2 and 3, respectively; anti-HAV seropositivity (S+) rates were 97, 99 and 99%, respectively. In group 1, anti-HBs SP rate was non-inferior as well as superior and anti-HAV S+ rate was non-inferior to that in groups 2 and 3. Anti-HBs response was most significantly influenced by the vaccine regimen, followed by age, gender and BMI (stepwise multiple regression analysis). BMI had the most significant influence on HAV response followed by age, gender and vaccine regimen. In conclusion, Twinrix induced superior hepatitis B SP rates and similar hepatitis A S+ rates compared to concomitant administration of monovalent vaccines in subjects aged >40 years.

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.

Hepatitis A and B Booster Recommendations: Implications for Travelers

Hepatitis A and B are serious vaccine-preventable diseases with a predominantly overlapping epidemiological distribution. Travelers, a term encompassing a range of individuals, are at risk of contracting these diseases if they are unvaccinated. Although the benefits of the primary vaccination course of hepatitis A and B vaccines are clear, the administration of hepatitis A and B boosters varies worldwide. Recommendations on the need for booster vaccinations have recently been published, and the implications of these recommendations for travelers are discussed in this review. Until a greater understanding is reached on the immunogenicity of hepatitis A and B vaccines in certain special groups (e.g., immunocompromised persons), there will be a need to monitor antibody levels to assess whether booster vaccinations are required. However, for the majority of immunocompetent travelers, the full primary vaccination course will provide protection from both hepatitis A and B infection in the long term, without the need for boosters.

Combined reduced-antigen-content diphtheria–tetanus–acellular pertussis and polio vaccine (dTpa-IPV) for booster vaccination of adults

Many countries recommend diphtheria, tetanus and/or poliomyelitis boosters in adolescents or adults and the need for pertussis booster vaccination beyond childhood is increasingly recognized. A new combined reduced-antigen-content dTpa-IPV vaccine provides booster vaccination against all four diseases in one single injection. The immunogenicity and safety of the dTpa-IPV vaccine was compared to that of licensed dTpa+IPV or Td-IPV vaccines in 806 adolescents >14 years of age and adults with a heterogeneous vaccination history. The dTpa-IPV vaccine was immunogenic and well tolerated. No clinically significant differences were observed between groups. Anti-tetanus antibody kinetics indicated that each of the vaccines could be used for tetanus prophylaxis in acute wound management. For all vaccines, the lowest post-vaccination antibody concentrations were observed in subjects >40 years of age, those seronegative prior to vaccination and those subjects whose last vaccination was > or =20 years ago. In conclusion, dTpa-IPV vaccination of subjects over 14 years of age was as immunogenic and well tolerated as the licensed dTpa+IPV or Td-IPV vaccines. Vaccination coverage of adults is poor and the use of combined vaccines such as dTpa-IPV during vaccination visits, or for wound management, maximizes opportunities for boosting in these difficult to reach age groups.

Epidemiology of travelers' diarrhea: details of a global survey

BACKGROUND

Recent epidemiologic data on travelers' diarrhea (TD) are essential for the evaluation of conventional and future prophylactic and therapeutic measures.

METHODS

To determine the epidemiology, including risk factors, impact and quality-of-life evaluation of TD, a cross-sectional survey was conducted over 12 months at the airports of Mombasa (Kenya), Goa (India), Montego Bay (Jamaica) and Fortaleza (Brazil) by distributing questionnaires to visitors just prior to their flying home. The study period was March 1996 to July 1998.

RESULTS

Overall, 73,630 short-term visitors completed a questionnaire. The total diarrhea attack rate varied between a high of 54.6% in Mombasa and a low of 13.6% in Fortaleza, but only between 31.5% and 5.4% of all travelers had classic TD. The 14-day incidence rates varied between 19.5% and 65.7%. Few travelers meticulously avoided potentially dangerous food items, although in India and Kenya most travelers avoided those considered most dangerous. Risk factors were stays exceeding 1 week, age between 15 and 30 years, and residence in the UK. The impact, measured as incapacity or quality-of-life scores, was very considerable.

CONCLUSIONS

TD continues to affect vacationers and business travelers as frequently as it did some 20 years ago. Compliance with recommendations to reduce exposure to pathogens by avoiding dangerous food items is poor among travelers from all countries. Implementation of food safety education programs may be difficult to achieve.

Serological investigation of the prevalence of anti-dengue IgM and IgG antibodies in Attapeu Province, South Laos

The prevalence of dengue antibodies was determined in the Attapeu region of South Laos with 225 blood samples collected from mostly febrile patients during the rainy season August - October 2001. An IgM capture ELISA was positive for one (0.4%) sample, while 177 (79%) samples were positive in an indirect IgG ELISA. Of the positive IgG samples, 20 (11.3%) were also positive on blood slides for Plasmodium falciparum. Dengue fever seems to be widespread in this area, but clinical dengue diagnosis remains difficult, especially in the first days of illness when physicians have to discriminate between dengue and other febrile illnesses.

Prophylaxis failure due to probable mefloquine resistant P falciparum from Tanzania

Failures of mefloquine prophylaxis in travellers returning from Africa have been reported repeatedly. Non-compliance to chemoprophylaxis is considered to be a major factor for failure. Only few reports on mefloquine prophylaxis failure in sub-Saharan Africa were able to report blood levels of the drug that were sufficient for prophylactic effectiveness. We report the case of a 44-year-old German female who travelled to Tanzania for 3 weeks. The patient reported that she never missed a dose of mefloquine during her weekly prophylaxis schedule. Four weeks after returning from Tanzania, the patient presented with fever, headache and myalgia. Only a few trophozoites of Plasmodium falciparum were found in a thick film. Blood levels of mefloquine at that stage were at 1400 ng/ml, thus largely excluding non-compliance and malabsorption. To our knowledge, this is the first case of confirmed prophylaxis failure due to mefloquine resistance in East Africa.

Therapeutic efficacy of chloroquine plus sulphadoxine/ pyrimethamine compared with monotherapy with either chloroquine or sulphadoxine/pyrimethamine in uncomplicated Plasmodium falciparum malaria in Laos

In a southern border province of Lao PDR, we compared the efficacy of antimalarial drug combinations in patients aged >or=1 year with uncomplicated Plasmodium falciparum malaria: monotherapy with either mefloquine (MQ), chloroquine (CQ), or sulphadoxine/pyrimethamine (SP) vs. the combination of both CQ and SP. Follow-up time was 14 days. Of 265 P. falciparum positive patients, 119 were enrolled in the drug trial. Significantly more patients treated with CQ than with SP developed early or late treatment failure [44.8%vs. 17.9%, relative risk (RR) = 2.51, 95% CI 1.03-6.12]. In the SP group, 82.1% were sensitive and 17.9% were treatment failures. The combination treatment CQ plus SP resulted in 83.3% sensitivity and 16.7% treatment failures. Combination treatment has no advantage over monotherapy with SP (RR = 1.01, 95% CI 0.8-1.3). All patients who received MQ for treatment (total dose 25 mg/kg) were cured within the 14 days of follow-up. The findings of this study suggest that use of CQ as first-line treatment of uncomplicated malaria in the Lao PDR has to be reconsidered. The combination of both CQ and SP has been discussed as a cost-effective alternative treatment, but in our patient population achieved no better results than single therapy with SP.

[How do pediatricians vaccinate in Munich? A health care epidemiological study]

OBJECTIVES

The goal was to determine vaccination rates and predictors of vaccination behaviour of pediatricians in Munich, Germany.

METHODS

Standardised questionnaires were sent to all 133 office-based pediatricians in Munich.

RESULTS

97 questionnaires (73%) were returned completely. Vaccination rates were sufficiently against diphtheria, tetanus, and poliomyelitis only. The other vaccinations recommended by the national immunisation advisory board (STIKO) were carried out to an insufficient extent. Vaccination rates of measles, mumps, and rubella were low. Parents' informed consent to STIKO's recommendations was the main determining factor of vaccination rates. Physicians' uncertainty in assessing contra-indications correctly was another important reason for insufficient vaccination rates.

CONCLUSIONS

The health target of eliminating measles will not likely be reached. STIKO's recommendations as well as periodically vocational training courses, should be more compulsory to physicians. Self-responsibility of patients and parents should be raised by financial incentives on sick funds premiums.

Molecular surveillance of drug resistance through imported isolates of Plasmodium falciparum in Europe

BACKGROUND

Results from numerous studies point convincingly to correlations between mutations at selected genes and phenotypic resistance to antimalarials in Plasmodium falciparum isolates. In order to move molecular assays for point mutations on resistance-related genes into the realm of applied tools for surveillance, we investigated a selection of P. falciparum isolates that were imported during the year 2001 into Europe to study the prevalence of resistance-associated point mutations at relevant codons. In particular, we tested for parasites which were developing resistance to antifolates and chloroquine. The screening results were used to map the prevalence of mutations and, thus, levels of potential drug resistance in endemic areas world-wide.

RESULTS

337 isolates have been tested so far. Prevalence of mutations that are associated with resistance to chloroquine on the pfcrt and pfmdr genes of P. falciparum was demonstrated at high levels. However, the prevalence of mutations associated with resistance to antifolates at the DHFR and DHPS genes was unexpectedly low, rarely exceeding 60% in endemic areas.

CONCLUSIONS

Constant screening of imported isolates will enable TropNetEurop to establish a screening tool for emerging resistance in endemic areas.

Combined vaccination against hepatitis A, hepatitis B, and typhoid fever: safety, reactogenicity, and immunogenicity

BACKGROUND

The etiological agents of hepatitis A, hepatitis B, and typhoid fever share similar patterns of global distribution, and cause significant disease burden in travelers to endemic countries. Combined vaccination against all three diseases, based on currently available vaccines, would promote compliance and convenience for travelers. This clinical study evaluated the feasibility of extemporaneously syringe-mixed hepatitis A and B vaccine (Twinrix) and a Vi polysaccharide vaccine (Typherix) in healthy adults, and compared this to concomitant administration of the vaccines in separate arms.

METHODS

The mixed dose of vaccine contained at least 720 enzyme-linked immunosorbent assay (ELISA) units of the inactivated hepatitis A antigen, 20 microg of the recombinant hepatitis B antigen and 25 microg of the Vi polysaccharide typhoid antigen in 1.5 mL. The study was conducted in 200 healthy 18- to 45-year-old volunteers.

RESULTS

Equivalence between the vaccines mixed before administration and the concomitantly administered vaccines was shown in terms of seroconversion and seroprotection. With the exception of local injection site soreness, which was higher in the mixed administration group, the reactogencity was similar for both groups. In both vaccination groups more than 95% of the subjects were anti-hepatitis A virus and anti-Vi seropositive 1 month after the first vaccination. With regard to hepatitis B, a strong response was achieved in both groups, with more than two-thirds of the subjects protected 2 months after the start of the immunization course.

CONCLUSION

These results support the feasibility of extemporaneously syringe-mixed combined hepatitis A and B vaccine with a Vi polysaccharide typhoid vaccine, administered in healthy adults.

Prevalence of enteric pathogens among international travelers with diarrhea acquired in Kenya (Mombasa), India (Goa), or Jamaica (Montego Bay)

Stools from tourists from Europe and North America who acquired diarrhea in Mombasa (Kenya), Goa (India), or Montego Bay (Jamaica) were examined for enteric pathogens. Enterotoxigenic Escherichia coli (ETEC) was the most common pathogen (25%) identified in the 3 locations. Isolation of Shigella species was more frequent in Goa and Mombasa than in Montego Bay (10%, 9%, and 0.3%, respectively; P <.005). Viruses (rotaviruses and enteric adenoviruses) were found in 9% of travelers to the 3 areas. Of 275 ETEC isolates in this study, 158 (57%) produced a defined colonization factor antigen (CFA). Coli surface 6 (CS6) was the most frequent and was found in 41%-52% of CFA/CS-positive ETEC isolates. The frequency of resistance among bacterial enteropathogens to traditional antimicrobial agents was particularly high throughout the study period in all 3 regions. Quinolones were active against the bacterial enteropathogens in the 3 sites.

[Changes in the antibiotic sensitivity of urinary tract pathogens (author's transl)]

The resistance of 2,314 bacterial strains from 1968 to 1972 was investigated drawing on case histories from the Munich University Urological Clinic. Using the disc-diffusion method 12,160 sensitivity tests were conducted with these strains against gentamicin, co-trimoxazole, ampicillin, tetracycline and chloramphenicol. The material was compiled from 35,000 individual data by means of modern electronic data processing and evaluated according to variable criteria. As expected the incidence of resistance in hospital-acquired pathogens was considerably higher than that in community-acquired pathogens; however, the resistance pattern of hosptial-acquired pathogens remained essentially unchanged from 1968 to 1972, whereas a significant increase of resistance in community-acquired infections was recorded. It can thus be concluded that the methods used in this clinic for combatting hospital infection and a more critical attitude towards anti-bacterial therapy have had positive results. An express warning is issued against unspecific antibacterial therapy which is often administered outside the clinic on the pretext of long-term therapy. In the light of the resistance situation of urinary tract pathogens, antibiotics should be used sparingly, keeping in mind the acidification of urine and the wash-out principle by means of high fluid intake.