Inter-allelic recombination in the Plasmodium vivax merozoite surface protein 1 gene among Indian and Colombian isolates.

BACKGROUND: A major concern in malaria vaccine development is the polymorphism observed among different Plasmodium isolates in different geographical areas across the globe. The merozoite surface protein 1 (MSP-1) is a leading vaccine candidate antigen against asexual blood stages of malaria parasite. To date, little is known about the extent of sequence variation in the Plasmodium vivax MSP-1 gene (Pvmsp-1) among Indian isolates. Since P. vivax accounts for >50% of malaria cases in India and in Colombia, it is essential to know the Pvmsp-1 gene variability in these two countries to sustain it as a vaccine candidate. The extent of polymorphism in Pvmsp-1 gene among Indian and Colombian isolates is described. METHODS: The sequence variation in the region encompassing the inter-species conserved blocks (ICBs) five and six of Pvmsp-1 gene was examined. PCR was carried out to amplify the polymorphic region of Pvmsp-1 and the PCR products from twenty (nine Indian and 11 Colombian) isolates were sequenced and aligned with Belem and Salvador-1 sequences. RESULTS: Results revealed three distinct types of sequences among these isolates, namely, Salvador-like, Belem-like and a third type sequence which was generated due to interallelic recombination between Salvador-like sequences and Belem-like sequences. Existence of the third type in majority (44%) showed that allelic recombinations play an important role in PvMSP1 diversity in natural parasite population. Micro-heterogeneity was also seen in a few of these isolates due to nucleotide substitutions, insertions as well as deletions. CONCLUSIONS: Intergenic recombination in the Pvmsp-1 gene was found and suggest that this is the main cause for genetic diversity of the Pvmsp-1 gene.

Clinical and laboratory findings of Plasmodium vivax malaria in Colombia, 2001.

A descriptive study was carried out in 104 patients with Plasmodium vivax malaria, from the region of Turbo (Antioquia, Colombia). Clinical features and levels of hemoglobin, glycemia, serum bilirubin, alanine-aminotransferase (ALT), aspartate-aminotransferase (AST), creatinine and complete blood cell profile were established. 65% of the studied individuals were men and their mean age was 23. Of all individuals 59% had lived in the region for > 1 year and 91% were resident in the rural area. 42% were farmers and 35% had a history of malaria. The mean parasitaemia was 5865 parasites/mm3. The evolution of the disease was short (average of 4.0 days). Fever, headache and chills were observed simultaneously in 91% of the cases while the most frequent signs were palmar pallor (46%), jaundice (15%), hepatomegaly (17%), and spleen enlargement (12%). Anemia was found in 39% of the women and in 51% of the men, 8% of individuals had thrombocytopaenia and 41% had hypoglycemia.

Clinical and laboratory findings of Plasmodium vivax malaria in Colombia, 2001

A descriptive study was carried out in 104 patients with Plasmodium vivax malaria, from the region of Turbo (Antioquia, Colombia). Clinical features and levels of hemoglobin, glycemia, serum bilirubin, alanine-aminotransferase (ALT), aspartate-aminotransferase (AST), creatinine and complete blood cell profile were established. 65 percent of the studied individuals were men and their mean age was 23. Of all individuals 59 percent had lived in the region for > 1 year and 91 percent were resident in the rural area. 42 percent were farmers and 35 percent had a history of malaria. The mean parasitaemia was 5865 parasites/mm . The evolution of the disease was short (average of 4.0 days). Fever, headache and chills were observed simultaneously in 91 percent of the cases while the most frequent signs were palmar pallor (46 percent), jaundice (15 percent), hepatomegaly (17 percent), and spleen enlargement (12 percent). Anemia was found in 39 percent of the women and in 51 percent of the men, 8 percent of individuals had thrombocytopaenia and 41 percent had hypoglycemia

Detección de anticuerpos antimaláricos en un grupo de escolares del municipio del El Bagre, Antioquia / Antimalaric antiobodies in school children in El Bagre, Colombia

En 1996, en el municipio de El Bagre (Antioquia-Colombia), zona endémica para malaria y con altos niveles de desnutrición, se realizó un estudio de casos y controles con el objeto de determinar la relación entre el estado nutricional y la respuesta inmune humoral de niños con y sin malaria. Se trabajó con un grupo de 100 niños entre 4 y 9 años de edad, 51 con malaria y 49 sin ella, al cual se le determinaron los niveles de anticuerpos antimaláricos IgG e IgM por la técnica de inmunofluorescencia indirecta (IFI), empleando antigenos de P. falciparum cepa FCB 2 mantenida en cultivo continuo. El estado nutricional se evaluó por comparación de las medidas antropométricas con la referencia de crecimiento del National Center for Health Statistics (NCHS) de los Estados Unidos. Los resultados mostraron diferencias en la tasa de positividad de anticuerpos IgG entre los niños maláricos y los no maláricos. En efecto: Veintinueve niños maláricos (56.9 por ciento) y sólo 4 de los no maláricos (8.2 por ciento) tenían dichos anticuerpos (P<0.00001 ); la diferencia también fue significativa para el antecedente de malaria en el último año que fue de 70.6 por ciento en los niños maláricos y 10.2 por ciento en los no maláricos (p<0.00001 ). Todas las determinaciones de IgM fueron negativas. Por último, de los 29 seropositivos con malaria, 20 (69 por ciento) eran desnutridos (p<0.01 ).

A cases and controls study was carried out in1996 in El Bagre, Colombia, endemic zone for ma.laria, in order to determine the relationship betweennutritional situation and immune response to mala-ria in 51 children with malaria and 49 without it; IgGand IgM antibodies were determined by means ofindirect inmunofluorescence .against P. falciparumantigens (Strain FCB2). Nutritional situation wasevaluated according to USA National Center forHealth Statistics.No child was found positive for IGM antibodies;concerning IgG response, it was positive in 29(56.9%) malaric children but only in 4 (8.2%) of thenon-malaric ones (p<0.00001 ). Difference was alsosignjficant (p<0.00001) for malarja antecedents inthe previous year (70.6% in malaric children vs10.2% jn the nonmalaric ones). Of the 29 malaricseropositive children 20 (69%) were malnourrished(p<0.01 )