Toxocariasis diagnosed in international travelers at the Institute of Tropical Medicine, Antwerp, Belgium, from 2000 to 2013.

Although infection with Toxocara canis or T. catis (commonly referred as toxocariasis) appears to be highly prevalent in (sub)tropical countries, information on its frequency and presentation in returning travelers and migrants is scarce. In this study, we reviewed all cases of asymptomatic and symptomatic toxocariasis diagnosed during post-travel consultations at the reference travel clinic of the Institute of Tropical Medicine, Antwerp, Belgium. Toxocariasis was considered as highly probable if serum Toxocara-antibodies were detected in combination with symptoms of visceral larva migrans if present, elevated eosinophil count in blood or other relevant fluid and reasonable exclusion of alternative diagnosis, or definitive in case of documented seroconversion. From 2000 to 2013, 190 travelers showed Toxocara-antibodies, of a total of 3436 for whom the test was requested (5.5%). Toxocariasis was diagnosed in 28 cases (23 symptomatic and 5 asymptomatic) including 21 highly probable and 7 definitive. All but one patients were adults. Africa and Asia were the place of acquisition for 10 and 9 cases, respectively. Twelve patients (43%) were short-term travelers (< 1 month). Symptoms, when present, developed during travel or within 8 weeks maximum after return, and included abdominal complaints (11/23 symptomatic patients, 48%), respiratory symptoms and skin abnormalities (10 each, 43%) and fever (9, 39%), often in combination. Two patients were diagnosed with transverse myelitis. At presentation, the median blood eosinophil count was 1720/µL [range: 510-14160] in the 21 symptomatic cases without neurological complication and 2080/µL [range: 1100-2970] in the 5 asymptomatic individuals. All patients recovered either spontaneously or with an anti-helminthic treatment (mostly a 5-day course of albendazole), except both neurological cases who kept sequelae despite repeated treatments and prolonged corticotherapy. Toxocariasis has to be considered in travelers returning from a (sub)tropical stay with varying clinical manifestations or eosinophilia. Prognosis appears favorable with adequate treatment except in case of neurological involvement.

Serious altitude illness in travelers who visited a pre-travel clinic.

BACKGROUND: Few data are available on the incidence and predictors of serious altitude illness in travelers who visit pre-travel clinics. Travel health consultants advise on measures to be taken in case of serious altitude illness but it is not clear if travelers adhere to these recommendations. METHODS: Visitors to six travel clinics who planned to travel to an altitude of ≥3,000 m were asked to complete a diary from the first day at 2,000 m until 3 days after reaching the maximum sleeping altitude. Serious altitude illness was defined as having symptoms of serious acute mountain sickness (AMS score ≥ 6) and/or cerebral edema and/or pulmonary edema. RESULTS: The incidence of serious altitude illness in the 401 included participants of whom 90% reached ≥4,000 m, was 35%; 23% had symptoms of serious AMS, 25% symptoms of cerebral edema, and 13% symptoms of pulmonary edema. Independent predictors were young age, the occurrence of dark urine, travel in South America or Africa, and lack of acclimatization between 1,000 and 2,500 m. Acetazolamide was brought along by 77% of the responders of whom 41% took at least one dose. Of those with serious altitude illness, 57% had taken at least one dose of acetazolamide, 20% descended below 2,500 m on the same day or the next, and 11% consulted a physician. CONCLUSIONS: Serious altitude illness was a very frequent problem in travelers who visited pre-travel clinics. Young age, dark urine, travel in South America or Africa, and lack of acclimatization nights at moderate altitude were independent predictors. Furthermore, we found that seriously ill travelers seldom followed the advice to descend and to visit a physician.

Self-diagnosis of malaria by travelers and expatriates: assessment of malaria rapid diagnostic tests available on the internet.

INTRODUCTION: In the past malaria rapid diagnostic tests (RDTs) for self-diagnosis by travelers were considered suboptimal due to poor performance. Nowadays RDTs for self-diagnosis are marketed and available through the internet. The present study assessed RDT products marketed for self-diagnosis for diagnostic accuracy and quality of labeling, content and instructions for use (IFU). METHODS: Diagnostic accuracy of eight RDT products was assessed with a panel of stored whole blood samples comprising the four Plasmodium species (n = 90) as well as Plasmodium negative samples (n = 10). IFUs were assessed for quality of description of procedure and interpretation and for lay-out and readability level. Errors in packaging and content were recorded. RESULTS: Two products gave false-positive test lines in 70% and 80% of Plasmodium negative samples, precluding their use. Of the remaining products, 4/6 had good to excellent sensitivity for the diagnosis of Plasmodium falciparum (98.2%-100.0%) and Plasmodium vivax (93.3%-100.0%). Sensitivity for Plasmodium ovale and Plasmodium malariae diagnosis was poor (6.7%-80.0%). All but one product yielded false-positive test lines after reading beyond the recommended reading time. Problems with labeling (not specifying target antigens (n = 3), and content (desiccant with no humidity indicator (n = 6)) were observed. IFUs had major shortcomings in description of test procedure and interpretation, poor readability and lay-out and user-unfriendly typography. Strategic issues (e.g. the need for repeat testing and reasons for false-negative tests) were not addressed in any of the IFUs. CONCLUSION: Diagnostic accuracy of RDTs for self-diagnosis was variable, with only 4/8 RDT products being reliable for the diagnosis of P. falciparum and P. vivax, and none for P. ovale and P. malariae. RDTs for self-diagnosis need improvements in IFUs (content and user-friendliness), labeling and content before they can be considered for self-diagnosis by the traveler.

Schistosomiasis in Belgian military personnel returning from the Democratic Republic of Congo.

The detection of schistosomiasis cases among Belgian military personnel returning from a mission in the Democratic Republic of Congo (DRC) prompted a nested case-control study of all military personnel deployed in the DRC between 2005 and 2008 to identify all infections and to start appropriate treatment. Of 197 patients exposed at Lake Tanganyika in the Kalemie area of DRC, 49 (24.9%) were diagnosed with schistosomiasis. Swimming was significantly more frequent than wading in the seropositive group than in the seronegative group (88.9% vs. 73.6%; odds ratio [OR], 2.86; 95% confidence interval [CI], 0.97-9.01). Thirty-one of 49 patients (63.3%) were symptomatic; including skin problems in 34.7%, respiratory symptoms in 12.2%, fever in 14.3%, and 51.0% with gastrointestinal problems. Median eosinophil counts were significantly higher in seropositive patients (375 vs. 138 per tL; Wilcoxon rank sum test [Ws] = 10,559.00; p < 0.01; r = -0.49). In total, 20 (40.8%) of the 49 patients were treated for symptomatic infections and the remainder for asymptomatic schistosomiasis. Our study emphasizes the need for active systematic post-tropical screening in military personnel after deployment to Schistosoma-endemic regions of the world.

Acute mountain sickness in travelers who consulted a pre-travel clinic.

BACKGROUND: The main objective of this study was to investigate the incidence and predictors of acute mountain sickness (AMS) in travelers who consulted a pre-travel clinic and the compliance with advices concerning this condition. METHODS: A post-travel questionnaire was sent to clients of five travel clinics who planned to climb above 2,000 m. RESULTS: The response was 77% and the data of all 744 respondents who stayed above 2,500 m were used for the analysis. Eighty-seven percent (646) read and understood the written advices on AMS. The incidence of AMS was 25% (184), and the predictors were previous AMS [odds ratio (OR) 2.2], female sex (OR 1.6), age (OR 0.98 per year), maximum sleeping altitude (OR 1.2 per 500 m), and the number of nights between 1,500 and 2,500 m (OR 0.9 per night). Eighty-seven percent of respondents understood the written advices about AMS but 21% did not read or understand the use of acetazolamide. Forty percent spent less than two nights between 1,500 and 2,500 m and 43% climbed more than 500 m/d once above 2,500 m. Acetazolamide was brought along by 541 respondents (72%) and 116 (16%) took it preventively. Of those with AMS 62 (34%) took acetazolamide treatment and 87 (47%) climbed higher despite AMS symptoms. The average preventive dose of acetazolamide was 250 mg/d, while the average curative dose was 375 mg/d. We found no relation between acetazolamide prevention and AMS (p = 0.540). CONCLUSIONS: The incidence of AMS in travelers who stayed above 2,500 m was 25%. Predictors were previous AMS, female sex, age, maximum overnight altitude, and the number of nights between 1,500 and 2,500 m. Only half of these travelers followed the preventive and curative advices and 21% did not read or understand the use of acetazolamide. We found no preventive effect of a low dose of acetazolamide in this retrospective observational study.

Therapy of vector-borne protozoan infections in nonendemic settings.

Vector-borne protozoan infections are responsible for a wide variety of illnesses (mainly malaria, trypanosomiasis and leishmaniasis) affecting tropical and subtropical areas, but increasingly diagnosed in nonendemic settings. This article summarizes the therapeutic developments for these conditions during the past decade and focuses specifically on treatment recommendations for returning travelers and migrants. The treatment of malaria has known the most spectacular improvements. Progress in the management of leishmaniasis and trypanosomiasis has also been substantial and includes introduction of new drugs into clinical practice, combinations of existing drugs, or new laboratory tools for treatment monitoring as well as extension of treatment indications to new groups of patients. Serious gaps still exist in terms of effectiveness and tolerance. Since the research pipeline is very limited for the coming 5-10 years, optimized combinations of existing drugs need to be urgently explored.

Schistosomiasis in travellers and migrants.

Schistosomiasis is a tropical parasitic disease caused by blood-dwelling fluke worms of the genus Schistosoma whose infective stages, the cercariae, are amplified through mollusks acting as intermediate hosts. People are infected when exposed to fresh water containing cercariae that penetrate the skin. There are however considerable differences in intensity of infection and morbidity, depending on the pattern of exposure and the infective species. In travellers, schistosomiasis differs substantially from infection in endemic populations in many aspects: geography, morbidity, treatment and prevention. In migrants, schistosomiasis manifests itself in a way more akin to what is seen in endemic populations. In this paper we will review the specific issues associated with schistosomiasis in travellers and migrants, with emphasis on the acute disease manifestations in non-immune persons, and on neuroschistosomiasis as a potential severe complication. We discuss new trends in diagnosis and treatment with respect to the specific disease stage, and summarize precautionary measures and novel ways to prevent Schistosoma infection in travellers.

Anaphylaxis in an airplane after insecticide spraying.

Flights departing from malarious areas are sprayed with pyrethroids. They are presumed to be safe since reports of adverse responses among passengers or crew were only anecdotal. However, asthmatic reactions after domestic and occupational exposure have been published. We present the first case description of pyrethroid allergy in an airplane.

Vaccinations in patients with immune-mediated inflammatory diseases.

Patients with immune-mediated inflammatory diseases (IMID) such as RA, IBD or psoriasis, are at increased risk of infection, partially because of the disease itself, but mostly because of treatment with immunomodulatory or immunosuppressive drugs. In spite of their elevated risk for vaccine-preventable disease, vaccination coverage in IMID patients is surprisingly low. This review summarizes current literature data on vaccine safety and efficacy in IMID patients treated with immunosuppressive or immunomodulatory drugs and formulates best-practice recommendations on vaccination in this population. Especially in the current era of biological therapies, including TNF-blocking agents, special consideration should be given to vaccination strategies in IMID patients. Clinical evidence indicates that immunization of IMID patients does not increase clinical or laboratory parameters of disease activity. Live vaccines are contraindicated in immunocompromized individuals, but non-live vaccines can safely be given. Although the reduced quality of the immune response in patients under immunotherapy may have a negative impact on vaccination efficacy in this population, adequate humoral response to vaccination in IMID patients has been demonstrated for hepatitis B, influenza and pneumococcal vaccination. Vaccination status is best checked and updated before the start of immunomodulatory therapy: live vaccines are not contraindicated at that time and inactivated vaccines elicit an optimal immune response in immunocompetent individuals.

Trends of norfloxacin and erythromycin resistance of Campylobacter jejuni/Campylobacter coli isolates recovered from international travelers, 1994 to 2006.

BACKGROUND: Campylobacter sp. is a major cause of bacterial enterocolitis and travelers' diarrhea. Empiric treatment regimens include fluoroquinolones and macrolides. METHODS: Over the period 1994 to 2006, 724 Campylobacter jejuni/Campylobacter coli isolates recovered from international travelers at the outpatient clinic of the Institute of Tropical Medicine, Antwerp, Belgium, were reviewed for their susceptibility to norfloxacin and erythromycin. RESULTS: Norfloxacin resistance increased significantly over time in isolates from travelers returning from Asia, Africa, and Latin America. For the years 2001 to 2006, norfloxacin resistance rates were 67 (70.5%) of 95 for Asia, 20 (60.6%) of 33 for Latin America, and 36 (30.6%) of 114 for Africa. The sharpest increase was noted for India, with no resistance in 1994, but 41 (78.8%) of 52 resistant isolates found during 2001 to 2006. Erythromycin resistance was demonstrated in 20 (2.7%) isolates, with a mean annual resistance of 3.1% +/- 2.8%; resistance increased over time, with up to 3(7.5%) of 40 and 3 (8.6%) of 35 resistant isolates in 2004 and 2006, respectively (p < 0.05); there was no apparent geographic association. Combined resistance to norfloxacin and erythromycin was observed in five isolates. CONCLUSIONS: The high resistance rates to fluoroquinolones warrant reconsideration of their use as drugs of choice in patients with severe gastroenteritis when Campylobacter is the presumed cause. Continued monitoring of the incidence and the spread of resistant Campylobacter isolates is warranted.

Fever after a stay in the tropics: clinical spectrum and outcome in HIV-infected travelers and migrants.

OBJECTIVE: To investigate the epidemiology and clinical spectrum of fever in HIV-infected returning travelers and migrants. METHODS: From April 2000 to December 2006, we explored prospectively, at our referral travel/HIV clinics, the etiology and outcome of febrile illnesses developing within 3 months after a stay in the tropics. For this study, we compared the morbidity profile between HIV-infected individuals and all other cases tested HIV negative. RESULTS: Of the 1850 adults (15 years and older) evaluated for 1921 fever episodes, 93 (5%) had HIV infection, including 5 presenting with primary infection. HIV prevalence was 2% in western travelers or expatriates, 11% in travelers "visiting friends and relatives," and 24% in foreign visitors/migrants. Fever episodes (n = 104) occurring in the HIV-infected individuals were mainly due to opportunistic infections (23%, including tuberculosis), respiratory tract infections (20%), sexually transmitted infections (9%), and noninfectious diseases (7%). All these conditions were more frequently diagnosed than in HIV-negative travelers (1035 fever episodes), although tropical infections (mostly malaria) were proportionally less prevalent. Morbidity (rate and duration of hospitalization) was more considerable in HIV-infected patients than in HIV-negative individuals. CONCLUSIONS: HIV infection was frequent in returning travelers and migrants presenting with fever at our setting and affected strongly the diagnostic spectrum and overall morbidity.

Evaluation of the GIDEON expert computer program for the diagnosis of imported febrile illnesses.

OBJECTIVE: The authors evaluate the performance of the expert system Global Infectious Diseases and Epidemiology Network (GIDEON) in diagnosing febrile illnesses occurring after a stay in the tropics. METHODS: One investigator (E.B.) entered into the program the collected characteristics of 161 febrile travelers randomly extracted from a database of 1842 cases prospectively included during a study on imported fever. Accuracy was considered acceptable if the correct diagnosis appeared in the top 5 GIDEON ranking list. Interuser agreement was assessed by J.V.d.E. and J.M., who also entered the data of the first 50 sample cases with an established diagnosis. RESULTS: The sample was epidemiologically and clinically representative of the whole cohort. An infectious etiology had been established in 129 cases; diagnosis was unknown in 31 cases and non-infectious in 1 case. GIDEON generated a median of 29 diagnoses per case, including 23 with a probability lower than 1%. Accuracy was acceptable in 64% of the 129 fevers with infectious etiology. It tended to decrease when more than 3 findings were entered per case. Eleven (8%) severe conditions were rejected by GIDEON because non-disease-related characteristics had been introduced. In other cases, the posttest probability was inadequately affected by the insufficient weight of absent relevant findings. Interuser agreement was good for acceptable accuracy and final ranking (kappa=0.83 and 0.72, respectively). CONCLUSION: The performance of GIDEON in diagnosing imported fever is relatively good and reproducible but is impaired by some conceptual weaknesses. Its use might be hazardous for inexperienced physicians.

Eosinophilic meningitis due to Angiostrongylus cantonensis in a Belgian traveller.

Eosinophilic meningitis is a rare clinical entity. The most frequent cause in travellers to the tropics is infection with the rat lungworm Angiostrongylus cantonensis. In this report, we describe a case of eosinophilic meningitis due to infection with this nematode in a traveller who presented with slight headache, diarrhoea, general malaise and thoracic radicular pain after a trip through Latin America and the Fiji Islands. She responded less than optimally to repeated steroid and albendazole treatments, but finally recovered completely.

Sexual risk behavior of travelers who consulted a pretravel clinic.

OBJECTIVE: The objective of this study was to determine to which degree travelers who received pretravel advice at a travel clinic have protected or unprotected sexual contact with a new partner and what factors influence this behavior. METHOD: An anonymous questionnaire was sent to travelers who came to a pretravel clinic between June 1 and August 31, 2005. Risk factors for casual travel sex and predictors of protected sex were studied in a multivariate model. RESULTS: A total of 1,907 travelers were included (response rate 55%) in the study. Only 4.7% of the respondents had sexual contact with a new partner, and 63.1% of these new partners were from the country of destination. Of those who had casual travel sex, 52.4% did not expect this (women 75%), 30.9% did not always use condoms, and 41% were not protected against hepatitis B. Independent risk factors for casual travel sex were traveling without steady partner (OR 14.4), expecting casual travel sex (OR 9.2), having casual sexual contacts in the home country (OR 2.4), non-tourist journeys (OR 2.2), being male (OR 2.1), the fact that the information on sexually transmitted infections (STI) had been read (OR 2.0), and traveling to South and Central America (OR 2.0). Taking condoms along (OR 5.4) and reading the information on STI (OR 3.3) were identified as independent predictors of protected sex. CONCLUSIONS: Travelers have substantial sexual risk behavior. Casual sex is usually not expected, and the most important predictor is traveling without a steady partner. We would advice every client of a travel clinic who will travel without a steady partner to read the STI information, to take condoms along, and to be vaccinated against hepatitis B.

Factors influencing standard pretravel health advice--a study in Belgium.

BACKGROUND: Travelers with risk factors, medical conditions such as immunosuppression, medication intake, pregnancy, or elderly age, need adaptation or reinforcement of pretravel health advice. The literature provides little data on the frequency of these risk groups in the travel population. This study intended to investigate whether risk factors influencing standard travel advice are common in the population attending our travel clinic. METHODS: A prospective survey was carried out over a 2-month period in 2004 at the travel clinic of the Institute for Tropical Medicine in Antwerp, Belgium. A list of risk factors focused on the following three important advice categories: malaria prophylaxis, yellow fever vaccination, and travelers' diarrhea or other enteric infections. We counted how frequently a risk factor was observed for each advice category (potential influence) and, after considering the travel characteristics, how often a real adaptation of advice was necessary (actual influence). RESULTS: Of 2,227 travelers, 276 were found to have a possible influencing factor (12.4%). The potential influence was 10.9% (243/2,227) for malaria prophylaxis advice, 6.1% (136/2,227) for yellow fever vaccination, and 1.9% (43/2,227) for travelers' diarrhea advice. The actual influence was lower 8% (184/2,227), 5% (109/2,227), and 1.2% (27/2,227), respectively. The main interfering factors were as follows: for influence on malaria advice, age>or=60 years (44%) and neuropsychiatric disorders (15.6%); for yellow fever vaccination, age>or=60 years (63.2%) and immunosuppression (10.3%); and for influence on travelers' diarrhea advice, decreased gastric acidity (44.2%) and immunosuppression (32.6%). CONCLUSION: Travelers with risk factors are not infrequently seen at our travel clinic. Some groups are more prominently present and could be the focus of travel group-specific instructions. The study suggests that being informed about risk groups is essential for advising travelers.

Travel-acquired scrub typhus: emphasis on the differential diagnosis, treatment, and prevention strategies.

Scrub typhus should be considered in any febrile patient presenting with a macular rash, a polyadenopathy, an eschar, or a history of environmental exposure in endemic areas. The differential diagnosis includes malaria, typhoid fever, leptospirosis, and arboviroses. Doxycycline 100 mg twice daily for 7 days should be initiated as soon as the disease is suspected.