Human African trypanosomiasis in endemic populations and travellers.

Human African trypanosomiasis (HAT) or sleeping sickness is caused by the protozoan parasites Trypanosoma brucei (T.b.) gambiense (West African form) and T.b. rhodesiense (East African form) that are transmitted by the bite of the tsetse fly, Glossina spp.. Whereas most patients in endemic populations are infected with T.b. gambiense, most tourists are infected with T.b. rhodesiense. In endemic populations, T.b. gambiense HAT is characterized by chronic and intermittent fever, headache, pruritus, and lymphadenopathy in the first stage and by sleep disturbances and neuro-psychiatric disorders in the second stage. Recent descriptions of the clinical presentation of T.b. rhodesiense in endemic populations show a high variability in different foci. The symptomatology of travellers is markedly different from the usual textbook descriptions of African HAT patients. The onset of both infections is almost invariably an acute and febrile disease. Diagnosis and treatment are difficult and rely mostly on old methods and drugs. However, new molecular diagnostic technologies are under development. A promising new drug combination is currently evaluated in a phase 3 b study and further new drugs are under evaluation.

[Diagnosis of parasite infections. Significance of serological examinations]. / Diagnostik von Parasiteninfektionen: stellenwert der serologie.

The attractiveness of tropical and subtropical travel destinations for European tourists as well as the continuous influx of immigrants originating from such areas force the general practitioner to consider the possibility of parasitic infections. Besides the classic microscopic examination for ova and parasites, a serological examination for antibodies has its value especially in the case of an infection with tissue parasites, for an early diagnosis during prepetancy or as a screening test in case of a blood eosinophilia after known exposure risk. The current report highlights possible diagnostic strategies, referring especially to the significance of a serological examination.

[Ectoparasitic diseases]. / Ektoparasitosen

Skin disorders are among the three most frequent health problems among returning travellers. Although ectoparasitic diseases are only a fraction of all skin problems, suspected lesions are often a reason to consult the GP after returning from low economy countries. Scabies presents in a variety of clinically different lesions and is a challenge to the physician, as are the residues of arthropode bites. A focused history and a careful clinical investigation is mandatory. Allergic reactions mirror the variety of individual modulation of immunological processes of ectoparasitic disorders. Further tropical and subtropical parasites such as tungiasis and myiasis are described in which simple measures result in dramatic improvement of major subjective suffering.

[Prophylaxis and therapy of malaria in the practice]. / Prophylaxe und Therapie der Malaria in der Praxis.

Malaria prophylaxis is often discussed among travelers. Different recommendations are confusing. This is partially due to the availability of drugs in different countries and to the fact that few evidence-based data exist. German and Swiss experts try to counteract the resulting uncertainties by providing almost identical recommendations for malaria prevention and management. Many factors influence the malaria risk. Travel style, duration and season of travel, the transmitting anopheline mosquitoes, the causative Plasmodia and resistance of the parasites against antimalarial drugs influence the recommendations. Malaria protection consists of various components. Exposure prophylaxis substantially reduces the risk of infection. Drugs for chemoprophylaxis and standby emergency medications are available in industrialized countries. If malaria infection is readily diagnosed, the infection can always be successfully treated.

Plasmodium falciparum cerebral malaria complicated by disseminated intravascular coagulation and symmetrical peripheral gangrene: case report and review.

The case of a 56-year-old female tourist who survived cerebral Plasmodium falciparum malaria with disseminated intravascular coagulation and symmetrical peripheral gangrene, ultimately requiring amputation of her left-sided fingertips and toes, is reported. While symmetrical peripheral gangrene has been described rarely in Asian, African, and American patients with Plasmodium falciparum malaria and disseminated intravascular coagulation, no such case has been reported in travelers returning from endemic areas.

The use of ultrasound in schistosomiasis.

Ultrasound was introduced in the 1970s as a method to detect schistosomal pathology both at hospital and field level. It has since been established as a safe, rapid, non-invasive and relatively inexpensive technique for assessing schistosomiasis-related lesions in individual patients and in community surveys. It can be used to validate laboratory tests to measure morbidity and provides an opportunity to visualize the evolution of pathological lesions after treatment. The interpretation of ultrasound imaging depends on the experience of the investigators and it may not be the ideal tool to detect early lesions of the affected organs. This paper reviews and critically discusses the present knowledge of morbidity due to the different types of schistosomiasis as it can be observed using ultrasound, with special reference to its use as a diagnostic and monitoring tool in field surveys. It analyses the practical use, benefits and drawbacks of ultrasound investigations to assess pathological lesions due to schistosomiasis in relation to other diagnostic tools. The role of ultrasound investigations among other monitoring approaches in control programmes is discussed in the context of rational control strategies.

Quantitative assessment of eosinophiluria in Schistosoma haematobium infections: a new marker of infection and bladder morbidity.

Eosinophiluria, as quantified by measuring eosinophil cationic protein (ECP) in urinary extracts, microhematuria, egg excretion, and ultrasound-detectable bladder pathology were recorded in Schistosoma haematobium-infected Tanzanian school children at a baseline survey and during an 18-month post-treatment follow-up study. Significant correlations were seen between urinary ECP levels, intensity of infection, and bladder pathology. Treatment resulted in a marked reduction in prevalence and intensity of infection, in a delayed and less marked reduction in ECP levels, and in a resolution of pathology. The overall diagnostic efficiency of the ECP test (cut-off value for the ECP > or =5 ng/ml) in relation to infection was comparable with that of egg count and microhematuria, but with a better sensitivity than a single egg count. In relation to bladder pathology, the diagnostic performance of the ECP test (cut-off value for the ECP > or =25 ng/ml) exceeded that of a single egg count. In addition, the ECP was better in discriminating between different grades of bladder pathology. The present study points to the ECP as a useful marker of both S. haematobium infection and of associated bladder morbidity reflecting the inflammatory status of the bladder wall.

Urine circulating soluble egg antigen in relation to egg counts, hematuria, and urinary tract pathology before and after treatment in children infected with Schistosoma haematobium in Kenya.

A cohort of 117 school children infected with Schistosoma haematobium was followed-up after therapy with praziquantel (0, 2, 4, 6, 12, and 18 months) and various infection and morbidity parameters (egg counts, hematuria, soluble egg antigen [SEA] in urine, and ultrasonography-detectable pathology) were quantified. At the onset of the study, 97% of the children were positive for S. haematobium with a geometric mean egg count of 45.7 eggs/10 ml of urine. Eighty-one percent of the children were positive for SEA in urine with a geometric mean SEA concentration of 218.8 ng/ml of urine. Ninety-two percent and 56% of the children were microhematuria positive and macrohematuria positive, respectively. Two months after treatment, all infection and morbidity indicators had significantly decreased. Reinfection after treatment as determined by detection of eggs in urine was observed by four months post-treatment while the other parameters remained low. The clearance of SEA was slower than that of egg counts while pathology resolved at an even slower pace. Levels of SEA and egg output showed similar correlations with ultrasound detectable pathology; these correlations were better than the correlation between hematuria and pathology.

Travel advice given by pharmacists.

BACKGROUND: In 1993 more than 1 million Swiss residents traveled to a tropical or subtropical country. Although most pretravel advice is given by general practitioners, a number of travelers also seek advice from pharmacists. Little is known about the quantity and quality of travel advice given or the sources of information used by this group. METHODS: One-hundred and twenty randomly selected pharmacists from three Swiss cantons were first interviewed in a cross-sectional study on the telephone. All study participants subsequently received a pretested questionnaire, in which most of the questions asked on the phone were repeated, with additional questions regarding the sources of information used for travel advice and the cooperation of general practitioners. Included in both parts of the study were two scenarios of fictive travelers seeking health advice for destinations frequently visited by Swiss tourists (Thailand and Kenya). RESULTS: Of 136 pharmacists approached, all who said they sometimes gave travel advice, agreed to participate (88%). Fifty-six percent of them give travel advice regularly (mean 2-3 times per month). General knowledge on the main health hazards was good, but for treatment of travelers' diarrhea, only 59% spontaneously mentioned the need for increased fluid intake, whereas 100 % recommended antidiarrheal drugs. Protection from the sun was mentioned only by 10 % of the respondents, and only 8 % said that the traveler should seek advice from a medical doctor. Over 95% could name the three most important measures against mosquito bites, although up to 20% still recommend Vitamin B1 as well. On the telephone, only 19% (for Thailand) and 31% (for Kenya) gave accurate advice on malaria protection, and 13% (for Thailand) and 3% (for Kenya) could make correct recommendations about vaccination. However, more than 50% said that in practice they would consult documentation before giving any advice, with the Bulletin of the Federal Office of Health (BFOH) being the most commonly used source of information. In the questionnaire interview, where documentation was used, the accuracy of advice increased, especially for malaria protection (74% correct for Thailand and 93% for Kenya). CONCLUSIONS: The overall knowledge of Swiss pharmacists on travel medicine issues is satisfactory. Specific questions need further attention, such as treatment of travelers' diarrhea, sun protection and advice on malaria prophylaxis and vaccinations. For the latter two, clients should also consult a medical doctor. Collaboration between doctors and pharmacists, and the consistency of the advice given, are important in improving compliance. Reliable information sources are available in pharmacies and are used.

Evolution of Schistosoma haematobium-related pathology over 24 months after treatment with praziquantel among school children in southeastern Tanzania.

Little is known about the dynamics of pathology due to schistosomiasis following treatment. Public health authorities in endemic areas require such information to decide on the timing of treatment and re-treatment schedules. A study to assess the rate of clearance and reappearance of pathologic lesions due to Schistosoma haematobium using ultrasound has now been carried out in two schools in southeastern Tanzania, an area of moderate-to-high transmission. Baseline data collection found urinary tract pathology in 67% of 533 children. Lesions of the bladder were significantly associated with egg positivity and microhematuria. The attributable fraction estimate of major bladder lesions due to S. haematobium was 75%. In a cohort study, 224 infected children were examined by ultrasound and then treated with a standard dose of 40 mg of praziquantel/kg of body weight. They were re-examined at two, four, six, 12, 18, and 24 months after treatment. Before treatment, 76% had pathologic lesions of the urinary tract. The proportion showing lesions decreased sharply during the first months after treatment to 11% at six months. At 24 months, lesions were detected in 57%, and 11% had developed new severe pathology. In 18 cases, pathology was present throughout, and 34 did not show any pathology throughout the study. This study provides the first detailed report on the evolution of urinary tract pathology due to S. haematobium infections at the community level. The results will help in making decisions on treatment and re-treatment schedules and more generally will provide a basis for designing control strategies in areas of moderate-to-high transmission.

Circumstances and management of 72 animal bites among long-term residents in the tropics.

Little is known about rabies exposure among expatriates living in warm climates. Recommendations on pre-exposure prophylaxis are therefore controversial. This study assesses the post-exposure management of Swiss and German expatriates after potential rabies exposures. Dogs were involved in 69% of all incidents. Less than half of the owned dogs were vaccinated against rabies. Only 24-30% of post-exposure treatments were correct according to WHO recommendations. Expatriates with pre-exposure vaccination appear to be complacent about post-exposure treatment. The decision to give pre-exposure vaccination to expatriates in warm climate countries or to rely on post-exposure rabies vaccination depends on the available quality of treatment and must be carefully assessed prior to a stay abroad. Information on rabies risk must be better disseminated and vaccination of owned animals improved.

[Current malaria management in Switzerland]. / Aktuelles Malariamanagement in der Schweiz.

Diagnosis and management of malaria in returning travellers must be treated as an emergency. A thorough travel history and a blood examination are prerequisites for diagnosis of the infection. Plasmodium vivax, P. ovale and P. malariae infections cause febrile illnesses that are usually not dangerous, but P. falciparum often causes complications that can be fatal. Hospitalization should therefore be considered in the latter cases. The clinical features of the disease are often non-specific (fever, headache, myalgia, sweating). Furthermore, mitigated and delayed courses of the illness due to sub-therapeutic antimalarial drug levels are recorded in patients who have taken incomplete chemosuppression. Chloroquine is still the treatment of choice in most cases of P. vivax, P. ovale and P. malariae infections. In P. falciparum malaria, chemoresistance in many parts of the world requires treatment with other antimalarials. Treatment should be started when there is strong suspicion of malaria even before the diagnosis is parasitologically confirmed. Quinine is the drug of choice in severe P. falciparum malaria. An intravenous loading dose is administered if no previous treatment has been given.