In vitro assessment of drug resistance in Plasmodium falciparum in five States of India.

Background & objectives: In vitro assays are an important tool to assess baseline sensitivity and monitor the drug response of Plasmodium falciparum over time and place and, therefore, can provide background information for the development and evaluation of drug policies. This study was aimed at determining the in vitro sensitivity of P. falciparum isolates to antimalarials. Methods: The in vitro activity of 108 P. falciparum isolates obtained from five States of India was evaluated using WHO microtest (Mark III) to chloroquine, monodesethylamodiaquine, dihydroartesunate and mefloquine. Samples were collected from the States of Orissa, Jharkhand, Karnataka, Goa and Chhattisgarh from September 2007 to August 2009. In addition, representative samples from different States of India cryopreserved and culture adapted in the Malaria Parasite Bank of National Institute of Malaria Research, New Delhi, were also evaluated. Results: The proportion of isolates resistant to chloroquine and monodesethylamodiaquine was 44.4 and 25 per cent, respectively. Of the 27 isolates resistant to monodesethylamodiaquine, 16 (59.3%) were cross-resistant to chloroquine. No isolate showed resistance to dihydroartesunate and mefloquine. Isolates from Orissa showed the highest degree of resistance to chloroquine and amodiaquine followed by Jharkhand. Forty two isolates were genotyped for pfcrt T76K chloroquine resistant mutation; mutations were seen in 38 (90.47%) isolates. Interpretation & conclusions: The Indian P. falciparum isolates showed a high degree of resistance to chloroquine followed by monodesethylamodiaquine. No resistance was recorded to mefloquine and dihydroartesunate.

Automated detection of malaria with haematology analyzer sysmex xe-2100.

Background: Diagnosis of malaria is usually made by microscopy [Giemsa, Acridine Orange (AO), and Quantitative Buffy Coat (QBC) assay], which requires expertise. Currently, automated haematology analyzers are being used for complete blood count (CBC), in all acute febrile and non-febrile illnesses which simultaneously detects malaria. The normal scattergram by the analyzer (Sysmex 2100) comprises of five parameters i.e. lymphocytes (pink), monocytes (green), neutrophils (blue), eosinophils (red) with a space between the neutrophil and eosinophil populations. Aims : We carried out a prospective study to compare the efficacy of Sysmex XE-2100 (Sysmex Corporation, Kobe) for detection of malaria in comparison to other conventional techniques. Materials and Methods : 430 cases were analyzed for malaria by microscopy (QBC, AO, Giemsa), ICT (Immunochromatography) and flowcytometric analyzer (Sysmex XE-2100). The abnormal scattergrams were observed as double neutrophil, double eosinophil, grey zone, extended neutrophil zone with a decrease space between eosinophil and neutrophil, and a combination of above patterns. Results : Out of 70 positive cases [49/70 (70%) P. vivax, 18/70 (25.7%) P. falciparum, and 3/70 (4.2%) both P. vivax and P. falciparum], 52 showed abnormal scattergrams by the analyzer. The sensitivity and specificity of hematology analyzer found to be 74.2% and 88%, respectively. Conclusion : Flowcytometric analyzer is a rapid, high throughput device which needs less expertization for the diagnosis of malaria. Hence, it can be used in the diagnostic laboratories as an early modality for diagnosis of malaria in suspected as well as clinically in apparent cases.

Evaluation of different methods for Plasmodia detection, in well defined population groups in an endemic area of Brazil

Mais de 500.000 casos novos de malaria foram notificados no Brasil, em 1992. P. falciparum and P. vivax sao as especies responsaveis por 99,3 por cento dos casos. O diagnostico precoce e indispensavel para inicio do tratamento adequado. Neste trabalho, apresentamos or resultados do metodo tradicional para a deteccao de plasmodios, gota espessa, e os resultados de metodos alternativos estudados: imunofluorescencia indireta com anticorpo policlonal anti-P. falciparum e QBC-metodo, em grupos populacionais bem definidos....

Uso de la tecnica inmuno-radiometrica (IRMA) en Anopheles de Colombia para la identificacion de esporozoitos de Plasmodium / Use of the immuno-radiometric technique (IRMA) in the colombian Anopheles for identification of Plasmodium sporozoites

El metodo inmuno-radiometrico (IRMA) que utiliza anticuerpos monoclonales con especificidad por la proteina CS de los esporozoitos de Plasmodium falciparum, se uso en el presente trabajo para determinar las tasas de infeccion de mosquitos del genero Anopheles (obtenidos en diversas regiones endemicas malaricas de Colombia). De las especies estudiadas, A.albimanus, A.darlingi, A.alloph y A.neomaculipalpus mostraron infecciones por P.falciparum. Solo las dos primeros habian sido incriminadas previamente como vectoras. Adicionalmente, A.albimanus fue el unico positivo para P.vivax. El metodo IRMA permitio en un corto tiempo y sobre un numero reducido de mosquitos determinar algunos probables vectores en el pais

Aislamiento y caracterizacion de cepas colombianas de Plasmodium falciparum / Isolation and characterization of colombian Plasmodium falciparum strains

Las cepas de P. Falciparum necesarias para los estudios de vacunas antimalaricas requieren de una completa caracterizacion que incluye la historia clinica del paciente, el sitio de origen y de aislamiento de la infeccion, la adaptacion al sistema de cultivo continuo, la sensibilidad a los antimalaricos, la presencia de nodulaciones (K+) en los eritrocitos infectados y la disponibilidad de las poblaciones originales de parasitos, ademas de su infectividad en primates del genero Aotus. Basados en estos criterios se aislaron y caracterizaron 8 cepas colombianas de P. Falciparum obtenidas en cuatro de las principales areas malaricas del pais. Una de ellas, la cepa FCB-1, ha sido adaptada en Aotus, en el cual desarrolla infecciones de alta virulencia. Las cepas cloroquina-resistentes parecen crecer en mejor forma que las sensibles, durante la fase de adaptacion al cultivo continuo, representando una de las hipotesis para la rapida dispersion de las poblaciones de parasitos resistentes a la cloroquina