Mercedes Subirats

Application of real-time PCR for the differentiation of Entamoeba histolytica and E. dispar in cyst-positive faecal samples from 130 immigrants living in Spain.

Abstract In an effort to improve the diagnosis of intestinal amoebiasis, a real-time PCR has been used for the detection and differentiation of Entamoeba histolytica and E. dispar infections in African or South American immigrants who live in Spain. Faecal samples from all of the 130 subjects had apparently been found to contain E. histolytica/E. dispar cysts by microscopical examination. Using the real-time PCR, E. histolytica DNA was detected in faecal samples from only 10 (7.7%) of the immigrants, with E. dispar DNA detected in the samples from another 117 (90.0%) of the subjects. The use of such PCR in the routine investigation of patients found positive for E. histolytica/E. dispar cysts (by microscopy) is recommended, especially in non-endemic areas.

Imported submicroscopic malaria in Madrid

BackgroundSubmicroscopic malaria (SMM) can be defined as low-density infections of Plasmodium that are unlikely to be detected by conventional microscopy. Such submicroscopic infections only occasionally cause acute disease, but they are capable of infecting mosquitoes and contributing to transmission. This entity is frequent in endemic countries; however, little is known about imported SMM.The goals of this study were two-fold: a) to know the frequency of imported SMM, and b) to describe epidemiological, laboratorial and clinical features of imported SMM.MethodsA retrospective study based on review of medical records was performed. The study population consisted of patients older than 15 years attended at the Tropical Medicine Unit of Hospital Carlos III, between January 1, 2002 and December 31, 2007. Routinely detection techniques for Plasmodium included Field staining and microscopic examination through thick and thin blood smear. A semi-nested multiplex malaria PCR was used to diagnose or to confirm cases with low parasitaemia.ResultsSMM was diagnosed in 104 cases, representing 35.5% of all malaria cases. Mean age (IC95%) was 40.38 years (37.41-43.34), and sex distribution was similar. Most cases were in immigrants, but some cases were found in travellers. Equatorial Guinea was the main country where infection was acquired (81.7%). Symptoms were present only in 28.8% of all SMM cases, mainly asthenia (73.3% of symptomatic patients), fever (60%) and arthromialgias (53.3%). The associated laboratory abnormalities were anaemia (27.9%), leukopaenia (15.4%) and thrombopaenia (15.4%). Co-morbidity was described in 75 cases (72.1%).ConclusionsResults from this study suggest that imported SMM should be considered in some patients attended at Tropical Medicine Units. Although it is usually asymptomatic, it may be responsible of fever, or laboratory abnormalities in patients coming from endemic areas. The possibility of transmission in SMM has been previously described in endemic zones, and presence of vector in Europe has also been reported. Implementation of molecular tests in all asymptomatic individuals coming from endemic area is not economically feasible. So re-emergence of malaria (Plasmodium vivax) in Europe may be speculated.Abstract in SpanishIntroducciónLa malaria submicroscópica (MSM) puede ser definida como una infección por Plasmodium de baja densidad, no detectable mediante microscopía convencional. Ocasionalmente produce enfermedad aguda, pero es capaz de producir infección el mosquito y ser transmitida. Es frecuente en regiones endémicas; sin embargo, existe poca información sobre la MSM importada.El objetivo de este estudio es doble: a) Conocer la frecuencia de MSM importada; b) Describir las caracetrísitcas epidemiológicas, analíticas y clínicas de la MSM importada.MétodosEstudio retrospectivo mediante revisión de historias clínicas. La población de estudio estaba formada por mayores de 15 años atendidos en la Unidad de Medicina Tropical del Hospital Carlos III, entre el 1 de enero de 2002 y el 31 de diciembre de 2007. Las técnicas rutinarias de detección de Plasmodium incluyen tinción de Field, gota gruesa y extensión. Una técnica de PCR (seminested multiplex) fue utilizada para el diagnostico o para confirmar casos con baja parasitemias.ResultadosLa MSM fue diagnosticada en 104 casos, representando el 35.5% de los casos de malaria. La edad media (IC95%) fue 40.38 años (37.41-43.34), y la distribución por sexos fue similar. La mayoría de los casos eran en inmigrantes, describiéndose también casos en viajeros. Guinea Ecuatorial fue el principal país de adquisición de la infección (81.7%). Los síntomas estaban presentes en el 28.8% de todos los casos de MSM, principalmente astenia (73.3% de los pacientes sintomáticos), fiebre (60%) y artromialgias (53.3%). Las anomalías analíticas asociadas fueron anemia (27.9%), leucopenia (15.4%) y trombopenia (15.4%). Había comorbilidad en 75 casos (72.1%).DiscusiónEstos resultados sugieren que debería considerarse la MSM importada en algunos pacientes atendidos en las Unidades de Medicina Tropical. Aunque suele ser asintomática, puede ser responsable de fiebre o alteraciones analíticas en provenientes de regiones endémicas. La posibilidad de transmisión de la MSM ha sido previamente demostrada, así como la presencia en Europa del vector. La implementación de tests moleculares a todos los individuos asintomáticos que provienen de regiones endémicas no es económicamente factible. Por tanto, se puede especular con la idea de la re-emergencia de malaria en Europa (al menos de P. vivax).

The use of PCR in the diagnosis of hyper-reactive malarial splenomegaly (HMS).

Between August 1997 and September 1998, 14 cases of hyper-reactive malarial splenomegaly (HMS) were diagnosed in the Instituto de Salud Carlos III in Madrid, Spain. These cases, from Equatorial Guinea and Cameroon, were identified using the diagnostic criteria established by Y. M. Fakunle in 1981: gross splenomegaly; high levels of anti-malarial antibodies; IgM in serum at least two standard deviations above the local mean; and clinical and immunological response to antimalarial treatment. Although malarial parasites were only detected in the Giemsa-stained blood films of four of the cases, these four and four others were found to have the DNA of such parasites in their blood when tested using a method based on a semi-nested, multiplex PCR. These result indicate that malarial parasitaemias may be more prevalent in HMS than is usually recognized.

Evaluación de dos métodos inmunocromatográficos comerciales para el diagnóstico rápido de Giardia duodenalis y Cryptosporidium spp. en muestras de heces

INTRODUCTION To assess and compare the performance of two immunochromatographic tests for the simultaneous detection of Giardia duodenalis and Cryptosporidium spp. in faeces. MATERIALS AND METHODS In this study 254 faeces samples were tested using the two immunochromatography strips Cryto-Giardia (CerTest Biotec) and Stick Crypto-Giardia (Operon). RESULTS In the diagnosis of G. duodenalis, the sensitivity and specificity of the kits were 97% and 100%, respectively for the CerTest; and 97% and 95% for Operon. In the diagnosis of Cryptosporidium spp. Certest strip rendering a sensitivity of 100%, compared to with a sensitivity of 92% using Operon. There were no false positives using either technique. CONCLUSIONS Both methods yielded good sensitivity and specificity values and are thus useful tools for a rapid diagnosis of G. duodenalis and Cryptosporidium spp. The benefits of immunochromatography methods are that there is no requirement for expert microscopists or special equipment.

Original breveEvaluación de dos métodos inmunocromatográficos comerciales para el diagnóstico rápido de Giardia duodenalis y Cryptosporidium spp. en muestras de hecesAssessment of two commercially available immunochromatographic assays for a rapid diagnosis of Giardia duodenalis and Cryptosporidium spp. in human fecal specimens

INTRODUCTION To assess and compare the performance of two immunochromatographic tests for the simultaneous detection of Giardia duodenalis and Cryptosporidium spp. in faeces. MATERIALS AND METHODS In this study 254 faeces samples were tested using the two immunochromatography strips Cryto-Giardia (CerTest Biotec) and Stick Crypto-Giardia (Operon). RESULTS In the diagnosis of G. duodenalis, the sensitivity and specificity of the kits were 97% and 100%, respectively for the CerTest; and 97% and 95% for Operon. In the diagnosis of Cryptosporidium spp. Certest strip rendering a sensitivity of 100%, compared to with a sensitivity of 92% using Operon. There were no false positives using either technique. CONCLUSIONS Both methods yielded good sensitivity and specificity values and are thus useful tools for a rapid diagnosis of G. duodenalis and Cryptosporidium spp. The benefits of immunochromatography methods are that there is no requirement for expert microscopists or special equipment.

Abnormal depolarizing patterns in three patients with filarial infection

Several authors have described a particular potential of automated depolarization analysis in detecting malaria infection as part of the routine full blood count (FBC) performed by the Cell-Dyn 4000 analyzer. In these cases, abnormal depolarizing patterns are due to the presence of leukocyte-associated malaria hemozoin, a pigment which depolarizes the laser light. In this report we describe samples from three individual patients who did not have malaria infection but showed abnormal depolarizing events. Further investigation determined that these samples were from patients infected by the nematode Mansonella perstans. The observed depolarizing pattern consisted of a normal depolarizing eosinophil population and in addition an abnormal depolarizing population that showed a close “linear” relationship between “granularity” (90° depolarization) and “lobularity” (90° polarization). This atypical population was smaller than normal leukocytes and thus clearly different from the patterns associated with malaria infection. Abnormal depolarization patterns of M. perstans clearly do not reflect leukocyte-associated malaria hemozoin. It is possible however that the erythrocyte-lysing agent used to facilitate leukocyte analysis by the instrument may have caused microfilaria fragmentation and thus the distinctive “straight-line” features of the abnormal scatter plots

Dermatological manifestations in onchocerciasis: A retrospective study of 400 imported cases

INTRODUCTION Onchocerciasis is caused by Onchocerca volvulus and mainly leads to pruritus and skin and visual disorders, including blindness. Seventeen million people are infected in 38 countries; 31 of these are in sub-Saharan Africa, six in Latin America and one on the Arabian Peninsula. More than 99% of cases occur in sub-Saharan Africa where 120 million people are at risk of infection. Eye disorders have been well-documented; however, skin disorders have not been described accurately. The objective of our study was to describe the epidemiology, main skin manifestations and treatment of imported onchocerciasis. MATERIAL AND METHODS A retrospective study was thus conducted by analysing the main demographic, clinical and treatment data regarding a cohort of 400 patients attending a reference clinical unit over a 17-year period. RESULTS Most patients were female (55%) with mean age 37.5±16.7 years. All the migrants came from sub-Saharan countries. The most frequently occurring dermatological symptom was pruritus. Ivermectin had been used as first-line therapy and adverse reactions had been described in 11 patients (3.2%). CONCLUSIONS The results indicate the fact that there should be a clinical suspicion of onchocerciasis regarding immigrants from endemic areas having skin lesions compatible with the diseases profile or asymptomatic patients having eosinophilia or unexplained high IgE. Moreover, skin snips from the buttocks region were very fruitful and treatment with ivermectin was seen to be safe. This is the largest case series regarding imported onchocerciasis described up to the present time.