The threshold model revisited.

BACKGROUND: The threshold model represents one of the most significant advances in the field of medical decision-making, yet it often does not apply to the most common class of clinical problems, which include health outcomes as a part of definition of disease. In addition, the original threshold model did not take a decision-maker's values and preferences explicitly into account. METHODS: We reformulated the threshold model by (1) applying it to those clinical scenarios, which define disease according to outcomes that treatment is designed to affect, (2) taking into account a decision-maker's values. RESULTS: We showed that when outcomes (eg, morbidity) are integral part of definition of disease, the classic threshold model does not apply (as this leads to double counting of outcomes in the probabilities and utilities branches of the model). To avoid double counting, the model can be appropriately analysed by assuming diagnosis is certain (P = 1). This results in deriving a different threshold-the threshold for outcome of disease (Mt ) instead of threshold for probability of disease (Pt ) above which benefits of treatment outweigh its harms. We found that Mt  ≤ Pt , which may explain differences between normative models and actual behaviour in practice. When a decision-maker values outcomes related to benefit and harms differently, the new threshold model generates decision thresholds that could be descriptively more accurate. CONCLUSIONS: Calculation of the threshold depends on careful disease versus utility definitions and a decision-maker's values and preferences.

Clinical and microscopic predictors of Entamoeba histolytica intestinal infection in travelers and migrants diagnosed with Entamoeba histolytica/dispar infection.

BACKGROUND: Amebiasis is a protozoal infection caused by Entamoeba histolytica, while the morphologically indistinguishable E. dispar is considered as non-pathogenic. Polymerase chain reaction (PCR) assays are necessary to differentiate both species. The most common clinical presentations of E. histolytica disease are amebic colitis and amebic liver abscess, but asymptomatic infection is also possible. We assessed the frequency and pattern of clinical symptoms and microscopic features in travelers/migrants associated with E. histolytica intestinal infection and compared them to those found in individuals with E. dispar infection. METHODS: We conducted a retrospective study at the travel clinic of the Institute of Tropical Medicine, Antwerp, Belgium on travelers/migrants found from 2006 to 2016 positive for Entamoeba histolytica/dispar through antigen detection and/or through microscopy confirmed by PCR. All files of individuals with a positive PCR for E. histolytica (= cases) and a random selection of an equal number of Entamoeba dispar carriers (= controls) were reviewed. We calculated the sensitivity, specificity and likelihood ratios (LRs) of clinical symptoms (blood in stool, mucus in stool, watery diarrhea, abdominal cramps, fever or any of these 5 symptoms) and of microscopic features (presence of trophozoites in direct and in sodium acetate-acetic acid-formalin (SAF)-fixed stool smears) to discriminate between E. histolytica and E. dispar infection. RESULTS: Of all stool samples positive for Entamoeba histolytica/dispar for which PCR was performed (n = 810), 30 (3.7%) were true E. histolytica infections, of which 39% were asymptomatic. Sensitivity, specificity and positive LRs were 30%, 100% and 300 (p 0.007) for presence of blood in stool; 22%, 100% and 222 (p 0.03) for mucus in stool; 44%, 90% and 4.7 (p 0.009) for cramps and 14%, 97% and 4.8 (p = 0.02) for trophozoites in direct smears. For watery diarrhea, fever and for trophozoites in SAF fixated smears results were non-significant. CONCLUSIONS: E. histolytica infection was demonstrated in a small proportion of travelers/migrants with evidence of Entamoeba histolytica/dispar infection. In this group, history of blood and mucus in stool and cramps had good to strong confirming power (LR+) for actual E. histolytica infection. Trophozoites were also predictive for true E. histolytica infection but in direct smears only.

Do travel clinic visitors read information on sexual risk abroad in travel health brochures?

BACKGROUND: A substantial proportion of travel clinic visitors have sexual encounters while abroad. Hence, guidelines on travel health recommend discussing sexual risk in a pre-travel consultation. However, previous studies showed that it often is not discussed. Although travel clinic visitors usually do receive written information on sexual risk abroad, few data are available on whether this information is read. Therefore, this prospective cohort study in travel clinic visitors was performed. METHODS: Travel clinic visitors were invited to complete a questionnaire after return from their journey. RESULTS: A total of 130 travellers (55%) responded. Half of them recorded they read the information on sexual risk. Male gender (OR 9.94 95% CI 3.12 - 31.63) and 'travelling with others' (OR 2.7 95% CI 1.29 - 5.78) were significant independent predictors of reading the information on sexual risk. High risk travellers, i.e. those travelling without a steady partner, were less likely to have read it. Although websites and apps were mentioned as better methods of providing information, none of the participants visited the websites on sexual behaviour and sexually transmitted infections recommended in the travel health brochure. CONCLUSION: Only half of travel clinic visitors read information on sexual risk in the health brochure received in the clinic and none of them visited the related websites mentioned in the brochure. Further research to identify the most effective way to inform travellers about sexual risk is needed.

Rationality, practice variation and person-centred health policy: a threshold hypothesis.

Variation in practice of medicine is one of the major health policy issues of today. Ultimately, it is related to physicians' decision making. Similar patients with similar likelihood of having disease are often managed by different doctors differently: some doctors may elect to observe the patient, others decide to act based on diagnostic testing and yet others may elect to treat without testing. We explain these differences in practice by differences in disease probability thresholds at which physicians decide to act: contextual social and clinical factors and emotions such as regret affect the threshold by influencing the way doctors integrate objective data related to treatment and testing. However, depending on a theoretical construct each of the physician's behaviour can be considered rational. In fact, we showed that the current regulatory policies lead to predictably low thresholds for most decisions in contemporary practice. As a result, we may expect continuing motivation for overuse of treatment and diagnostic tests. We argue that rationality should take into account both formal principles of rationality and human intuitions about good decisions along the lines of Rawls' 'reflective equilibrium/considered judgment'. In turn, this can help define a threshold model that is empirically testable.

A 68-year old male presenting with rhabdomyolysis-associated acute kidney injury following concomitant use of elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate and pravastatin/fenofibrate: a case report.

INTRODUCTION: We present what we believe to be the first case in the literature of rhabdomyolysis-induced renal failure caused by a probable drug interaction between elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (EVG/COBI/FTC/TDF) and pravastatin/fenofibrate. CASE PRESENTATION: A 68-year old Caucasian man presented with progressive pain in both legs two weeks after commencing treatment with EVG/COBI/FTC/TDF. He was found to have biochemical evidence of rhabdomyolysis and acute renal failure. CONCLUSION: We emphasize the need for post marketing surveillance of adverse effects of new products. Pharmacokinetic studies are necessary to investigate the levels of pravastatin in patients taking COBI and fenofibrate with and without other comorbidities. Meanwhile, we suggest that creatine kinase levels should be monitored and patients advised to report myalgias when using concomitant EVG/COBI/FTC/TDF and pravastatin/fenofibrate. This case serves as an important reminder to use estimated glomerular filtration rates rather than serum creatinine levels when choosing new medications. If potentially nephrotoxic combinations are started in patients with borderline estimated glomerular filtration rates, it may be prudent to check these filtration rates more frequently than usual. In patients with reduced estimated glomerular filtration rates, potentially nephrotoxic combinations should be avoided wherever possible.

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.

When is rational to order a diagnostic test, or prescribe treatment: the threshold model as an explanation of practice variation.

BACKGROUND: The threshold model represents an important advance in the field of medical decision-making. It is a linchpin between evidence (which exists on the continuum of credibility) and decision-making (which is a categorical exercise - we decide to act or not act). The threshold concept is closely related to the question of rational decision-making. When should the physician act, that is order a diagnostic test, or prescribe treatment? The threshold model embodies the decision theoretic rationality that says the most rational decision is to prescribe treatment when the expected treatment benefit outweighs its expected harms. However, the well-documented large variation in the way physicians order diagnostic tests or decide to administer treatments is consistent with a notion that physicians' individual action thresholds vary. METHODS: We present a narrative review summarizing the existing literature on physicians' use of a threshold strategy for decision-making. RESULTS: We found that the observed variation in decision action thresholds is partially due to the way people integrate benefits and harms. That is, explanation of variation in clinical practice can be reduced to a consideration of thresholds. Limited evidence suggests that non-expected utility threshold (non-EUT) models, such as regret-based and dual-processing models, may explain current medical practice better. However, inclusion of costs and recognition of risk attitudes towards uncertain treatment effects and comorbidities may improve the explanatory and predictive value of the EUT-based threshold models. CONCLUSIONS: The decision when to act is closely related to the question of rational choice. We conclude that the medical community has not yet fully defined criteria for rational clinical decision-making. The traditional notion of rationality rooted in EUT may need to be supplemented by reflective rationality, which strives to integrate all aspects of medical practice - medical, humanistic and socio-economic - within a coherent reasoning system.

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.

Intuitive weights of harm for therapeutic decision making in smear-negative pulmonary Tuberculosis: an interview study of physicians in India, Pakistan and Bangladesh.

BACKGROUND: To estimate the amount of regret and weights of harm by omission and commission during therapeutic decisions for smear-negative pulmonary Tuberculosis. METHODS: An interviewer-administered survey was done among young physicians in India, Pakistan and Bangladesh with a previously used questionnaire. The physicians were asked to estimate probabilities of morbidity and mortality related with disease and treatment and intuitive weights of omission and commission for treatment of suspected pulmonary Tuberculosis. A comparison with weights based on literature data was made. RESULTS: A total of 242 physicians completed the interview. Their mean age was 28 years, 158 (65.3%) were males. Median probability (%) of mortality and morbidity of disease was estimated at 65% (inter quartile range [IQR] 50-75) and 20% (IQR 8-30) respectively. Median probability of morbidity and mortality in case of occurrence of side effects was 15% (IQR 10-30) and 8% (IQR 5-20) respectively. Probability of absolute treatment mortality was 0.7% which was nearly eight times higher than 0.09% reported in the literature data. The omission vs. commission harm ratios based on intuitive weights, weights calculated with literature data, weights calculated with intuitive estimates of determinants adjusted without and with regret were 3.0 (1.4-5.0), 16 (11-26), 33 (11-98) and 48 (11-132) respectively. Thresholds based on pure regret and hybrid model (clinicians' intuitive estimates and regret) were 25 (16.7-41.7), and 2(0.75-7.5) respectively but utility-based thresholds for clinicians' estimates and literature data were 2.9 (1-8.3) and 5.9 (3.7-7.7) respectively. CONCLUSION: Intuitive weight of harm related to false-negatives was estimated higher than that to false-positives. The mortality related to treatment was eightfold overestimated. Adjusting expected utility thresholds for subjective regret had little effect.

Autochthonous cases of mycetoma in Europe: report of two cases and review of literature.

BACKGROUND: Mycetoma is a chronic granulomatous infection involving cutaneous and subcutaneous tissues. It is endemic in tropical and subtropical areas, but sporadic cases have been reported also in countries of temperate climate. The purpose of this paper is to review the cases of mycetoma in European subjects (and presumably acquired in Europe), to give an insight in the main factors associated with this condition, and to describe two previously unpublished cases observed at our Centre. METHODS AND FINDINGS: PubMed was systematically searched for case reports and case series of mycetoma in Europeans reported between 1980 and 2014, using specific search strategies. Two further cases diagnosed by the authors are described. Forty-two cases were collected. Eleven cases were caused by Scedosporium apiospermium, mainly in immunosuppressed patients from Bulgaria, Germany, the Netherlands, Portugal, Slovenia, Spain and the United Kingdom. Excluding all patients with immunosuppression, 29 cases remain. Most of them were reported from Bulgaria and in Albanian patients (all diagnosed outside Albania). In the Bulgarian case series many different micro-organisms, both bacteria and fungi, were isolated, while all the 5 cases from Albania were caused by Actinomadura spp. Other countries reporting cases were Greece, Italy and Turkey. In general, Actinomadura spp is the most frequent causative agent isolated, followed by Nocardia spp and Madurella mycetomatis. The foot was the most reported site involved. Most patients were medically treated, but unfortunately a long-term follow up (at least one year) was available only in a few cases. CONCLUSIONS: Our review and our own cases suggest that Europeans without travel history can be affected by Madura foot. The lack of a surveillance system is likely to cause an underreporting of cases. Moreover, the unfamiliarity of Western doctors with this peculiar infection may cause a mismanagement, including unnecessary amputations.

Three cases of imported dengue virus infection from Madeira to Belgium, 2012.

We report three laboratory-confirmed dengue virus (DENV) infections imported to Belgium by travelers returning from Madeira (Portugal). Despite the use of a mosquito-repellent spray as reported by two patients, the infection could not be prevented. Diagnosis was made by antigen detection and real-time reverse transcriptase polymerase chain reaction (RT-PCR) in two cases and by serology 1 month after onset of symptoms in a third one. The responsible virus was identified as DENV serotype 1, American/African genotype (genotype V). The close relationship to isolates from Colombia supports the previous findings that a South American strain originated the outbreak in Madeira in 2012.

The effect of pre-travel advice on sexual risk behavior abroad: a systematic review.

BACKGROUND: Travelers often have casual sex abroad and the risk of acquiring a sexually transmitted infection (STI) associated with casual travel sex is considered to be threefold higher compared to the risk of casual sex in the home country. Consequently, international guidelines recommend including STI advice in the pre-travel consultation. We performed a systematic review on the effect of a pre-travel STI intervention on sexual risk behavior abroad. METHODS: In September 2012, a systematic analysis and meta-analysis of peer reviewed literature were performed on the relation between pre-travel STI advice for travelers and sexual risk behavior abroad. Primary outcome measure consisted of the number of travelers with a new sexual partner abroad; secondary outcome measure entailed the proportion of consistent condom use. RESULTS: Six studies were identified for inclusion in the review, of which three clinical trials on the effect of a motivational intervention compared to standard pre-travel STI advice qualified for the meta-analysis. Two of these trials were performed in US marines deployed abroad and one in visitors of a travel clinic. The extensive motivational training program of the marines led to a reduction in sexual risk behavior, while the brief motivational intervention in the travel clinic was not superior to standard advice. The meta-analysis established no overall effect on risk behavior abroad. No clinical trials on the effect of a standard pre-travel STI discussion were found, but a cohort study reported that no relation was found between the recall of a nonstructured pre-travel STI discussion and sexual risk behavior, while the recall of reading the STI information appeared to be related to more consistent condom use. CONCLUSIONS: Motivational pre-travel STI intervention was not found to be superior to standard STI advice, while no clinical trials on the effect of standard pre-travel STI advice were found.

Factors for viral infection in blood donors of South Kivu in the Democratic Republic of Congo.

INTRODUCTION: Assessing the knowledge, attitudes, practices and behaviors among blood donors in South Kivu and identify risk factors for viral markers. METHODS: A descriptive and analytical cross-sectional study involved 595 blood donors in the city of Bukavu (Head city of the province of South Kivu) in the eastern Democratic Republic of Congo. RESULTS: Our sample consisted of 70.3% men with a median age of 23 and 77% of young people fewer than 30 years. The score of knowledge and attitude of blood donor's volunteer on blood safety were assessed at 23.5% and 79.1%. A statistically significant difference was observed between the loyal and new blood donors volunteer (25.1% vs 64.6% p < 0.001); between blood donors volunteer of low and high education level (p = 0.04). Motivation to donate blood in 95.9% of cases respect ethical rules of donation. The prevalence of viral markers in blood donors is as follows: 4.8% hepatitis B, 3.9% hepatitis C, 1.6% HIV. For HIV, the low level of education and replacement blood donors are most at risk, the antigen of hepatitis B is observed in blood donors over 30 years, blood donors living couple. CONCLUSION: General knowledge on blood safety is very low in the first link in the chain transfusion (blood donors). A good education of this population conducted by the transfusion service reinforced building (training and support) is needed.

A systematic review and meta-analysis of the performance of two point of care typhoid fever tests, Tubex TF and Typhidot, in endemic countries.

BACKGROUND: In the absence of well-equipped laboratory infrastructure in many developing countries the accurate diagnosis of typhoid fever is challenging. Rapid diagnostic tests (RDT) with good performance indicators would be helpful to improve clinical management of suspected cases. We performed a systematic literature review and meta- analysis to determine the performance of TUBEX TF and Typhidot for the diagnosis of typhoid fever using PRISMA guidelines. METHODS: Titles and abstracts were reviewed for relevance. Articles were screened for language, reference method and completeness. Studies were categorized according to control groups used. Meta-analysis was performed only for categories where enough data was available to combine sensitivity and specificity estimates. Sub-analysis was performed for the Typhidot test to determine the influence of indeterminate results on test performance. RESULTS: A total of seven studies per test were included. The sensitivity of TUBEX TF ranged between 56% and 95%, Specificity between 72% and 95%. Meta-analysis showed an average sensitivity of 69% (95%CI: 45-85) and an average specificity of 88% (CI95%:83-91). A formal meta-analysis for Typhidot was not possible due to limited data available. Across the extracted studies, sensitivity and specificity estimates ranged from 56% to 84% and 31% to 97% respectively. CONCLUSION: The observed performance does not support the use of either rapid diagnostic test exclusively as the basis for diagnosis and treatment. There is a need to develop an RDT for typhoid fever that has a performance level comparable to malaria RDTs.

Tuberculous meningitis: do modern diagnostic tools offer better prognosis prediction?

BACKGROUND: The British Medical Research Council (BMRC) staging has been extensively used to evaluate the disease severity and establish the approximate prognosis of tuberculous meningitis. AIMS: This study aimed at analyzing the predictive accuracy for mortality and neurological sequelae of a set of clinical features, laboratory tests and imaging. METHODS: We compared the British Medical Research Council (BMRC) staging with a new scoring proposal to predict the prognosis of patients with Central Nervous System Tuberculosis. Data from Ecuador was collected. A score was built using a Spiegelhalter and Knill-Jones method and compared with BMRC staging with a ROC curve. RESULTS: A total of 213/310 patients (68.7%) were in BMRC stage II or III. Fifty-seven patients died (18.3%) and 101 (32.5%) survived with sequelae. The associated predictors were consciousness impairment (p = 0.010), motor deficit (p = 0.003), cisternal effacement (p = 0.006) and infarcts (p = 0.015). The new score based on these predictors yielded a larger area under the curve of 0.76 (95% CI: 0.70-0.82), but not significantly different from the BMRC (0.72: 95% CI: 0.65-0.77). CONCLUSIONS: This modern score is easy to apply and could be a sound predictor of poor prognosis. However, the availability of modern tests did not improve the ability to predict a bad outcome.

Should malaria treatment be guided by a point of care rapid test? A threshold approach to malaria management in rural Burkina Faso.

BACKGROUND: In Burkina Faso, rapid diagnostic tests for malaria have been made recently available. Previously, malaria was managed clinically. This study aims at assessing which is the best management option of a febrile patient in a hyperendemic setting. Three alternatives are: treating presumptively, testing, or refraining from both test and treatment. The test threshold is the tradeoff between refraining and testing, the test-treatment threshold is the tradeoff between testing and treating. Only if the disease probability lies between the two should the test be used. METHODS AND FINDINGS: Data for this analysis was obtained from previous studies on malaria rapid tests, involving 5220 patients. The thresholds were calculated, based on disease risk, treatment risk and cost, test accuracy and cost. The thresholds were then matched against the disease probability. For a febrile child under 5 in the dry season, the pre-test probability of clinical malaria (3.2%), was just above the test/treatment threshold. In the rainy season, that probability was 63%, largely above the test/treatment threshold. For febrile children >5 years and adults in the dry season, the probability was 1.7%, below the test threshold, while in the rainy season it was higher (25.1%), and situated between the two thresholds (3% and 60.9%), only if costs were not considered. If they were, neither testing nor treating with artemisinin combination treatments (ACT) would be recommended. CONCLUSIONS: A febrile child under 5 should be treated presumptively. In the dry season, the probability of clinical malaria in adults is so low, that neither testing nor treating with any regimen should be recommended. In the rainy season, if costs are considered, a febrile adult should not be tested, nor treated with ACT, but a possible alternative would be a presumptive treatment with amodiaquine plus sulfadoxine-pyrimethamine. If costs were not considered, testing would be recommended.

Severe strongyloidiasis: a systematic review of case reports.

BACKGROUND: Strongyloidiasis is commonly a clinically unapparent, chronic infection, but immuno suppressed subjects can develop fatal disease. We carried out a review of literature on hyperinfection syndrome (HS) and disseminated strongyloidiasis (DS), in order to describe the most challenging aspects of severe strongyloidiasis. METHODS: We conducted a structured search using PubMed to collect case reports and short case series on HS/DS published from 1991 to 2011. We restricted search to papers in English, Spanish, Italian and French. Case reports were classified as HS/DS according to given definitions. RESULTS: Records screened were 821, and 311 were excluded through titles and abstract evaluation. Of 510 full-text articles assessed for eligibility, 213 were included in qualitative analysis. As some of them were short case series, eventually the number of cases analyzed was 244.Steroids represented the main trigger predisposing to HS and DS (67% cases): they were mostly administered to treat underlying conditions (e.g. lymphomas, rheumatic diseases). However, sometimes steroids were empirically prescribed to treat signs and symptoms caused by unsuspected/unrecognized strongyloidiasis. Diagnosis was obtained by microscopy examination in 100% cases, while serology was done in a few cases (6.5%). Only in 3/29 cases of solid organ/bone marrow transplantation there is mention of pre-transplant serological screening. Therapeutic regimens were different in terms of drugs selection and combination, administration route and duration. Similar fatality rate was observed between patients with DS (68.5%) and HS (60%). CONCLUSIONS: Proper screening (which must include serology) is mandatory in high - risk patients, for instance candidates to immunosuppressive medications, currently or previously living in endemic countries. In some cases, presumptive treatment might be justified. Ivermectin is the gold standard for treatment, although the optimal dosage is not clearly defined in case of HS/DS.