Combination therapy with rifampicin or fosfomycin in patients with Staphylococcus aureus bloodstream infection at high risk for complications or relapse: results of a large prospective observational cohort.

OBJECTIVES: To investigate whether Staphylococcus aureus bloodstream infection (SAB) patients at high risk for complications or relapse benefit from combination therapy with adjunctive rifampicin or fosfomycin. METHODS: In this post hoc analysis, SAB patients with native valve infective endocarditis, osteoarticular infections or implanted foreign devices were included. The co-primary endpoints were all-cause 90 day mortality and death or SAB-related late complications within 180 days. To overcome treatment selection bias and account for its time dependence, inverse probability of treatment weights were calculated and included in marginal structural Cox proportional hazard models (MSCMs). RESULTS: A total of 578 patients were included in the analysis, of which 313 (54%) received combination therapy with either rifampicin (n = 242) or fosfomycin (n = 58). In the multivariable MSCM, combination therapy was associated with a better outcome, that is, a lower rate of death or SAB-related late complications within 180 days (HR 0.65, 95% CI 0.46-0.92). This beneficial effect was primarily seen in patients with implanted foreign devices, in which combination therapy was associated with a lower rate of death or SAB-related late complications within 180 days (HR 0.53, 95% CI 0.35-0.79) and a lower 90 day mortality (HR 0.57, 95% CI 0.36-0.91). Upon agent-specific stratification, we found no significant differences in outcomes between combination therapy containing rifampicin and fosfomycin; however, the number of patients in most subgroups was not large enough to draw firm conclusions. CONCLUSIONS: In patients with implanted foreign devices, combination therapy was associated with a better long-term outcome. Larger prospective studies are needed to validate these findings.

Spatial distribution and incidence trend of human alveolar echinococcosis in southwest Germany: increased incidence and urbanization of the disease?

Ecology and epidemiology of Echinococcus multilocularis and human alveolar echinococcosis (AE) are changing in Central Europe. Our data from a regional referral center for AE in southwest Germany suggest rising regional incidence for AE (annual incidence per 100,000 population 2004-2011: 0.12; 2012-2019: 0.20) and emerging urban AE (of 7 cases of AE in Freiburg city dwellers none was diagnosed before 2012) calling for an intensification of E. multilocularis and AE surveillance and of AE prevention measures.

Investigating the Impact of Early Valve Surgery on Survival in Staphylococcus aureus Infective Endocarditis Using a Marginal Structural Model Approach: Results of a Large, Prospectively Evaluated Cohort.

BACKGROUND: The impact of valve surgery on outcomes of Staphylococcus aureus infective endocarditis (SAIE) remains controversial. We tested the hypothesis that early valve surgery (EVS) improves survival by using a novel approach that allows for inclusion of major confounders in a time-dependent way. METHODS: EVS was defined as valve surgery within 60 days. Univariable and multivariable Cox regression analyses were performed. To account for treatment selection bias, we additionally used a weighted Cox model (marginal structural model) that accounts for time-dynamic imbalances between treatment groups. To address survivor bias, EVS was included as a time-dependent variable. Follow-up of patients was 1 year. RESULTS: Two hundred and three patients were included in the analysis; 50 underwent EVS. All-cause mortality at day 30 was 26%. In the conventional multivariable Cox regression model, the effect of EVS on the death hazard was 0.85 (95% confidence interval [CI], .47-1.52). Using the weighted Cox model, the death hazard rate (HR) of EVS was 0.71 (95% CI, .34-1.49). In subgroup analyses, no survival benefit was observed in patients with septic shock (HR, 0.80 [CI, .26-2.46]), in NVIE (HR, 0.76 [CI, .33-1.71]) or PVIE (HR, 1.02 [CI, .29-3.54]), or in patients with EVS within 14 days (HR, 0.97 [CI, .46-2.07]). CONCLUSIONS: Using both a conventional Cox regression model and a weighted Cox model, we did not find a survival benefit for patients who underwent EVS in our cohort. Until results of randomized controlled trials are available, EVS in SAIE should be based on individualized decisions of an experienced multidisciplinary team. CLINICAL TRIALS REGISTRATION: German Clinical Trials registry (DRKS00005045).

Increasing numbers and complexity of Staphylococcus aureus bloodstream infection-14 years of prospective evaluation at a German tertiary care centre with multi-centre validation of findings.

OBJECTIVES: Staphylococcus aureus bloodstream infection (SAB) is a common and severe infection. This study aims to describe temporal trends in numbers, epidemiological characteristics, clinical manifestations, and outcomes of SAB. METHODS: We performed a post-hoc analysis of three prospective SAB cohorts at the University Medical Centre Freiburg between 2006 and 2019. We validated our findings in a large German multi-centre cohort of five tertiary care centres (R-Net consortium, 2017-2019). Time-dependent trends were estimated using Poisson or beta regression models. RESULTS: We included 1797 patients in the mono-centric and 2336 patients in the multi-centric analysis. Overall, we observed an increasing number of SAB cases over 14 years (6.4%/year and 1000 patient days, 95% CI: 5.1% to 7.7%), paralleled by an increase in the proportion of community-acquired SAB (4.9%/year [95% CI: 2.1% to 7.8%]) and a decrease in the rate of methicillin-resistant-SAB (-8.5%/year [95% CI: -11.2% to -5.6%]). All of these findings were confirmed in the multi-centre validation cohort (6.2% cases per 1000 patient cases/year [95% CI: -0.6% to 12.6%], community-acquired-SAB 8.7% [95% CI: -1.2% to 19.6%], methicillin-resistant S. aureus-SAB -18.6% [95% CI: -30.6 to -5.8%]). Moreover, we found an increasing proportion of patients with multiple risk factors for complicated/difficult-to-treat SAB (8.5%/year, 95% CI: 3.6% to 13.5%, p < 0.001), alongside an overall higher level of comorbidities (Charlson comorbidity score 0.23 points/year, 95% CI: 0.09 to 0.37, p 0.005). At the same time, the rate of deep-seated foci such as osteomyelitis or deep-seated abscesses significantly increased (6.7%, 95% CI: 3.9% to 9.6%, p < 0.001). A reduction of in-hospital mortality by 0.6% per year (95% CI: 0.08% to 1%) was observed in the subgroup of patients with infectious diseases consultations. DISCUSSION: We found an increasing number of SAB combined with a significant increase in comorbidities and complicating factors in tertiary care centres. The resulting challenges in securing adequate SAB management in the face of high patient turnover will become an important task for physicians.

Therapy of uncomplicated falciparum malaria in Europe: MALTHER - a prospective observational multicentre study.

BACKGROUND: Malaria continues to be amongst the most frequent infectious diseases imported to Europe. Whilst European treatment guidelines are based on data from studies carried out in endemic areas, there is a paucity of original prospective treatment data. The objective was to summarize data on treatments to harmonize and optimize treatment for uncomplicated malaria in Europe. METHODS: A prospective observational multicentre study was conducted, assessing tolerance and efficacy of treatment regimens for imported uncomplicated falciparum malaria in adults amongst European centres of tropical and travel medicine. RESULTS: Between December 2003 and 2009, 504 patients were included in 16 centres from five European countries. Eighteen treatment regimens were reported, the top three being atovaquone-proguanil, mefloquine, and artemether-lumefantrine. Treatments significantly differed with respect to the occurrence of treatment changes (p = 0.005) and adverse events (p = 0.001), parasite and fever clearance times (p < 0.001), and hospitalization rates (p = 0.0066) and durations (p = 0.001). Four recrudescences and two progressions to severe disease were observed. Compared to other regimens, quinine alone was associated with more frequent switches to second line treatment, more adverse events and longer inpatient stays. Parasite and fever clearance times were shortest with artemether-mefloquine combination treatment. Vomiting was the most frequent cause of treatment change, occurring in 5.5% of all patients but 9% of the atovaquone-proguanil group. CONCLUSIONS: This study highlights the heterogeneity of standards of care within Europe. A consensus discussion at European level is desirable to foster a standardized management of imported falciparum malaria.

Use of a simple criteria set for guiding echocardiography in nosocomial Staphylococcus aureus bacteremia.

BACKGROUND: Infective endocarditis (IE) is a severe complication in patients with nosocomial Staphylococcus aureus bacteremia (SAB). We sought to develop and validate criteria to identify patients at low risk for the development of IE in whom transesophageal echocardiography (TEE) might be dispensable. METHODS: Consecutive patients with nosocomial SAB from independent cohorts in Europe (Invasive S. aureus Infection Cohort [INSTINCT]) and North America (S. aureus Bacteremia Group [SABG]) were evaluated for the presence of clinical criteria predicting an increased risk for the development of IE (ie, prolonged bacteremia of >4 days' duration, presence of a permanent intracardiac device, hemodialysis dependency, spinal infection, and nonvertebral osteomyelitis). Patients were observed closely for clinical signs and symptoms of IE during hospitalization and a 3-month follow-up period. RESULTS: IE was present in 13 (4.3%) of 304 patients in the INSTINCT cohort and in 40 (9.3%) of 432 patients in the SABG cohort. Within 14 days after the first positive blood culture result, echocardiography was performed in 39.8% and 57.4% of patients in the INSTINCT and SABG cohorts, respectively. In patients with IE, the most common clinical prediction criteria present were prolonged bacteremia (69.2% vs 90% for INSTINCT vs SABG, respectively) and presence of a permanent intracardiac device (53.8% vs 32.5%). In total, 13 of 13 patients in the INSTINCT cohort and 39 of 40 patients in the SABG cohort with documented IE fulfilled at least 1 criterion (sensitivity, 100% vs. 97.5%; negative predictive value, 100% vs 99.2%). CONCLUSIONS: A simple criteria set for patients with nosocomial SAB can identify patients at low risk of IE. Patients who meet these criteria may not routinely require TEE.

Paenibacillus larvae Bacteremia in injection drug users.

Paenibacillus larvae causes American foulbrood in honey bees. We describe P. larvae bacteremia in 5 injection drug users who had self-injected honey-prepared methadone proven to contain P. larvae spores. That such preparations may be contaminated with spores of this organism is not well known among pharmacists, physicians, and addicts.

Staphylococcus aureus bloodstream infection in patients with ventricular assist devices-Management and outcome in a prospective bicenter cohort.

OBJECTIVES: Ventricular assist devices (VAD) are increasingly implanted in patients with terminal heart failure. Here we describe the clinical course, management and outcome of VAD patients with S. aureus bloodstream infection (SAB). METHODS: We conducted a post hoc analysis of data from 1073 patients who had been prospectively enrolled in two consecutive SAB bicenter cohort studies. Patients with VAD in situ at the onset of SAB were identified. Follow-up of patients was at least 90 days. RESULTS: Twelve VAD patients with SAB were identified. Compared to the overall cohort, patients with VAD presented more often with fever (92% vs. 65%) and septic shock (33% vs. 23%) and showed higher C-reactive protein levels (mean 244 vs. 132 g/ml). The median time to onset of SAB after device implantation was 161 days (range 24-790 days). 30-day mortality was comparable to the whole cohort (17% vs. 19%). Infection-related surgical interventions were performed in six patients. Hematogenous dissemination to distant foci was not found in any patient. One out of nine surviving patients required continuous suppressive antibiotic therapy. CONCLUSIONS: Mortality rates for VAD patients with SAB were comparable to SAB without VAD. No hematogenous disssemination or persistent infections were recorded, which might be associated with the prompt and aggressive antibiotic and surgical management in VAD patients. SAB per se does not preclude successful transplantation.

Staphylococcus aureus bacteremia in patients with rheumatoid arthritis - Data from the prospective INSTINCT cohort.

OBJECTIVES: Patients with rheumatoid arthritis (RA) are considered to be at increased risk of severe infections. We here describe the clinical characteristics, course and outcome of RA patients with Staphylococcus aureus bacteremia (SAB). METHODS: We conducted a post hoc analysis of data from a German bi-center prospective SAB cohort study (period 2006-2014). Patients were followed-up for one year. Primary and secondary outcomes were survival time and osteoarticular infection (OAI). RESULTS: A total of 1069 patients with SAB were analyzed, with 31 patients suffering from RA. RA patients showed significantly more often OAI (15/31 patients, 48% vs. 152/1038, 15%), disseminated infection (12/31, 39% vs. 164/1038, 16%) and severe sepsis/septic shock (12/31, 39% vs. 235/1038, 23%). Day-30 mortality in RA patients was 36% (vs. 19% in non-RA patients, p = 0.034), and day 90 mortality was 58% (vs. 32%, p = 0.003). Multivariate analyses confirmed RA to be an independent risk factor for death (HR 2.3, 95% CI 1.4-3.7) and OAI (OR 4.2, 95% CI 1.8-9.8). CONCLUSIONS: Patients with RA exhibit a complicated SAB course and a high mortality, their management is challenging. Adequate antibiotic treatment, prompt invasive diagnostic and therapeutic procedures like joint lavage or surgery are of pivotal importance. Joint damage due to RA may confer a higher risk of acquiring OAI than immunosuppression.

[Molecular epidemiological surveillance of markers for antimalarial drugs in Plasmodium falciparum isolates imported to Barcelona, Spain]. / Vigilancia epidemiológica mediante marcadores moleculares de resistencia frente a antimaláricos en aislados de Plasmodium falciparum importados a Barcelona, España.

BACKGROUND AND OBJECTIVE: There have been described compelling correlations between mutations in some Plasmodium falciparum genes and resistance to antimalarial drugs. To apply molecular techniques in the mechanisms of epidemiological surveillance in the Hospital Clínic of Barcelona and to map potential levels of resistance, we investigated the presence of mutations in the relevant codons of genes associated with resistance in P. falciparum isolates imported by travellers. PATIENTS AND METHOD: The genes pfctr, pfmdr1, dhfr, dhps and cytochrome b were analyzed by PCR and enzymatic restriction in P. falciparum isolates from 53 persons attending the Tropical Medicine Department after a trip to a malaria endemic area. RESULTS: 63% of patients were infected with a P. falciparum isolate with the K76T mutation in pfctr. Tyr86 in pfmdr1 was found in 54% of the isolates. Mutations in codons 51, 59 and 108 in dhfr were found in 33%, 49% and 44% of the isolates, respectively. Mutations in codons 436, 437 and 540 in dhps were found in 35%, 35% and 8.5% of the isolates. 30% of travellers were infected by parasites displaying 3 or more mutations in any of the codons of dhps and dhfr. None of the patients had a mutation in the Tyr268 codon of the cytochrome B gene. CONCLUSIONS: The high prevalence of mutations in the imported isolates suggests a fast development and expansion of resistance against most of the antimalarial drugs commonly used. The concurrence of more than one mutation in different loci suggests the expansion of multiple resistances.

Molecular surveillance of the antifolate-resistant mutation I164L in imported African isolates of Plasmodium falciparum in Europe: sentinel data from TropNetEurop.

BACKGROUND: Malaria parasites that carry the DHFR-mutation I164L are not only highly resistant to sulfadoxine-pyrimethamine but also to the new antimalarial drug chlorproguanil-dapsone. The spread of this mutation in Africa would result in a public health disaster since there is a lack of effective alternatives that are both affordable and safe. Up to now, this mutation has only been described in Asian and Latin-American countries. The objective of this study was to assess the prevalence of this mutation in African isolates of Plasmodium falciparum that have been imported into Europe through travellers. METHODS: TropNetEurop is a network for the surveillance of travel-associated diseases and seems to cover approximately 12% of all malaria cases imported into Europe. Within this network we screened 277 imported African isolates of P. falciparum with the help of PCR- and enzyme-digestion-methods for the antifolate-resistant mutation I164L. RESULTS: The I164L mutation was not detected in any of the isolates tested. DISCUSSION: Continuous molecular surveillance of mutations in P. falciparum, as it is practised within TropNetEurop, is an essential tool for the understanding and early detection of the spread of antimalarial drug resistance in Africa.

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.

Microarray-based genotyping and clinical outcomes of Staphylococcus aureus bloodstream infection: an exploratory study.

The clinical course of Staphylococcus aureus bacteremia varies extensively. We sought to determine the relationship between genetic characteristics of the infecting pathogen and clinical outcomes in an exploratory study. In two study centers, 317 blood culture isolates were analyzed by DNA microarray and spa genotyping. By uni- and multivariate regression analyses associations of genotype data with 30-day all-cause mortality, severe sepsis/septic shock, disseminated disease, endocarditis, and osteoarticular infection were investigated. Univariate analysis showed significant association between S. aureus genes/gene-clusters or clonal complexes and clinical endpoints. For example CC15 was associated with 30-day mortality and CC22 with osteoarticular infection. In multivariate analysis methicillin resistance (mecA, OR 4.8 [1.43-16.06]) and the beta-lactamase-gene (bla, OR 3.12 [1.17-8.30]) remained independently associated with 30-day mortality. The presence of genes for enterotoxins (sed/sej/ser) was associated with endocarditis (OR 5.11 [1.14-18.62]). Host factors such as McCabe classification (OR 4.52 [2.09-9.79] for mortality), age (OR 1.06 [1.03-1.10] per year), and community-acquisition (OR 3.40 [1.31-8.81]) had a major influence on disease severity, dissemination and mortality. Individual genotypes and clonal complexes of S. aureus can only partially explain clinical features and outcomes of S. aureus bacteremia. Genotype-phenotype association studies need to include adjustments for host factors like age, comorbidity and community-acquisition.

Differences in clinical manifestations of imported versus autochthonous leptospirosis in Austria and Germany.

Leptospirosis, a zoonosis occurring worldwide, has a broad spectrum of clinical manifestations. Recently, various countries observed an increase of severe anicteric cases. In Austria and Germany, growing numbers of imported cases are notified in addition to autochthonous infections. The aim of this study was to assess whether imported and autochthonous cases differ in clinical manifestations and outcome. We retrospectively analyzed 24 imported and 35 autochthonous cases treated in six infectious disease units between 1998 and 2008. To compare disease severity, patients were classified according to established independent risk factors for fatal outcome. Although severe leptospirosis (i.e., presence of > or = 1 independent risk factors for death) occurred in similar proportions of imported (67%) and autochthonous (86%) infections (P = 0.1), imported cases were significantly fewer icteric (13% versus 69%; P < 0.0001). In conclusion, an increasing incidence of severe anicteric imported cases of leptospirosis should be anticipated with rising global travel activities.

Mortality of S. aureus bacteremia and infectious diseases specialist consultation--a study of 521 patients in Germany.

OBJECTIVES: To evaluate the relationship between mortality of bloodstream infection due to Staphylococcus aureus and infectious diseases specialist consultation and other factors potentially associated with outcomes. METHODS: A 6-year cohort study was conducted at a 1600-bed university hospital. Consecutive adult patients with S. aureus bacteremia were assessed using a standardised data collection and review form. A new infectious diseases service increased its consultations for S. aureus bacteremia from 33% of cases in 2002 to >80% in 2007. Infectious disease consultation and other factors potentially associated with in-hospital mortality were analysed by multivariate logistic regression. RESULTS: A total of 521 patients were studied. All-cause in-hospital mortality was 22%, 90-day mortality was 32%. Factors significantly associated with in-hospital mortality in multivariate analysis were ICU admission (OR 5.8, CI 3.5-9.7), MRSA (OR 2.6, CI 1.4-4.9), age >/=60 years (OR 2.4, CI 1.4-4.2), a diagnosis of endocarditis (OR 2.8, CI 1.4-5.7), a non-fatal underlying disease/comorbidity according to the McCabe classification (OR 0.2, CI 0.1-0.4), and infectious disease specialist consultation (OR 0.6, CI 0.4-1.0). CONCLUSIONS: These data suggest that outcome of S. aureus bacteremia may be improved by an expert consultation service.

Severe dengue virus infection in travelers: risk factors and laboratory indicators.

BACKGROUND: Dengue fever is the most common arboviral disease in travelers. In countries where dengue virus is endemic, sequential (secondary) infections with different dengue virus serotypes are associated with disease severity. Data on severity and secondary infection rates in a population of travelers are lacking. METHODS: Intensified surveillance of dengue fever in travelers was performed within the European Network on Surveillance of Imported Infectious Diseases. Data were collected at 14 European clinical referral centers between 2003 and 2005. RESULTS: A total of 219 dengue virus infections imported from various regions of endemicity were reported. Serological analysis revealed a secondary immune response in 17%. Spontaneous bleeding was observed in 17 (8%) patients and was associated with increased serum alanine and aspartate aminotransferase levels and lower median platelet counts. Two (0.9%) patients fulfilled the World Health Organization (WHO) case definition for dengue hemorrhagic fever. However, 23 (11%) travelers had severe clinical manifestations (internal hemorrhage, plasma leakage, shock, or marked thrombocytopenia). A secondary immune response was significantly associated with both spontaneous bleeding and other severe clinical manifestations. CONCLUSIONS: In travelers, severe dengue virus infections are not uncommon but may be missed if the WHO classification is strictly applied. High liver enzyme levels and low platelet counts could serve as indicators of disease severity.

Screening for mutations related to atovaquone/proguanil resistance in treatment failures and other imported isolates of Plasmodium falciparum in Europe.

BACKGROUND: Two single-point mutations of the Plasmodium falciparum cytochrome b gene (Tyr268Asn and Tyr268Ser) were recently reported in cases of atovaquone/proguanil (Malarone) treatment failure. However, little is known about the prevalence of codon-268 mutations and their quantitative association with treatment failure. METHODS: We set out to assess the prevalence of codon-268 mutations in P. falciparum isolates imported into Europe and to quantify their association with atovaquone/proguanil treatment failure. Isolates of P. falciparum collected by the European Network on Imported Infectious Disease Surveillance between April 2000 and August 2003 were analyzed for codon-268 mutations, by use of polymerase chain reaction-restriction fragment-length polymorphism. RESULTS: We successfully screened 504 samples for the presence of either Tyr268Ser or Tyr268Asn. One case of Ser268 and no cases of Asn268 were detected. Therefore, we can be 95% confident that the prevalence of Ser268 in the European patient pool does not exceed 0.96% and that Asn268 is less frequent than 0.77%. In 58 patients treated with atovaquone/proguanil, Tyr268Ser was present in 1 of 5 patients with treatment failure but in 0 of 53 successfully treated patients. CONCLUSIONS: Tyr268Ser seems to be a sufficient, but not a necessary, cause for atovaquone/proguanil treatment failure. The prevalence of both codon-268 mutations is currently unlikely to be >1% in the European patient pool.

Vigilancia epidemiológica mediante marcadores moleculares de resistencia frente a antimaláricos en aislados de Plasmodium falciparum importados a Barcelona, España / Molecular epidemiological surveillance of markers for antimarial drugs in Plasmodium falciparum isolates imported to Barcelona, Spain

Fundamento y objetivo: Se han descrito correlaciones convincentes entre mutaciones en determinados genes de Plasmodium falciparum y la resistencia contra antimaláricos. Con la intención de aplicar las técnicas moleculares en los mecanismos de vigilancia epidemiológica en el Hospital Clínic de Barcelona, y para mapear grados potenciales de resistencia, investigamos la presencia de mutaciones en los codones relevantes de genes asociados a resistencias en aislados de P. falciparum importados por viajeros. Pacientes y método: Se analizó mediante reacción en cadena de la polimerasa (PCR) y restricción con enzimas el genotipo de los genes pfctr, pfmdr1, dhfr, dhps y citocromo B en cepas de P. falciparum aisladas de 53 pacientes diagnosticados en el Servicio de Medicina Tropical con síntomas de malaria después de haber realizado un viaje a zonas endémicas de malaria. Resultados: El 63% de los pacientes presentó un aislado de P. falciparum con la mutación K76T en pfctr. En el 54% de los aislados se encontró Tyr86 en pfmdr1. Las mutaciones en los codones 51, 59 y 108 de dhfr se encontraron en el 33, el 49 y el 44% de los aislados, respectivamente. Las mutaciones en los codones 436, 437 y 540 de dhps se encontraron en el 35, el 35 y el 8,5% de los aislados. El 30% de los viajeros estaba infectado por parásitos que presentaban 3 o más mutaciones en alguno de los codones de dhps y dhfr. Ninguno de los pacientes presentó mutado el codón Tyr268 en el gen del citocromo B. Conclusiones: La alta prevalencia de mutaciones en los aislados importados sugiere el rápido desarrollo y la expansión de resistencias a la mayoría de los antimaláricos comúnmente usados. La concurrencia de más de una mutación en localizaciones diferentes sugiere la expansión de resistencias múltiples, lo que pone así de manifiesto la ineficacia de la monoterapia con los antipalúdicos más comunes

Background and objective: There have been described compelling correlations between mutations in some Plasmodium falciparum genes and resistance to antimalarial drugs. To apply molecular techniques in the mechanisms of epidemiological surveillance in the Hospital Clínic of Barcelona and to map potential levels of resistance, we investigated the presence of mutations in the relevant codons of genes associated with resistance in P. falciparum isolates imported by travellers. Patients and method: The genes pfctr, pfmdr1, dhfr, dhps and cytocrhome b were analyzed by PCR and enzymatic restriction in P. falciparum isolates from 53 persons attending the Tropical Medicine Department after a trip to a malaria endemic area. Results: 63% of patients were infected with a P. falciparum isolate with the K76T mutation in pfctr. Tyr86 in pfmdr1 was found in 54% of the isolates. Mutations in codons 51, 59 and 108 in dhfr were found in 33%, 49% and 44% of the isolates, respectively. Mutations in codons 436, 437 and 540 in dhps were found in 35%, 35% and 8.5% of the isolates. 30% of travellers were infected by parasites displaying 3 or more mutations in any of the codons of dhps and dhfr. None of the patients had a mutation in the Tyr268 codon of the cytochrome B gene. Conclusions: The high prevalence of mutations in the imported isolates suggests a fast development and expansion of resistance against most of the antimalarial drugs commonly used. The concurrence of more than one mutation in different loci suggests the expansion of multiple resistances