Genetic diversity of Plasmodium vivax in Kolkata, India

BACKGROUND: Plasmodium vivax malaria accounts for approximately 60% of malaria cases in Kolkata, India. There has been limited information on the genotypic polymorphism of P. vivax in this malaria endemic area. Three highly polymorphic and single copy genes were selected for a study of genetic diversity in Kolkata strains. METHODS: Blood from 151 patients with P. vivax infection diagnosed in Kolkata between April 2003 and September 2004 was genotyped at three polymorphic loci: the P. vivax circumsporozoite protein (pvcs), the merozoite surface protein 1 (pvmsp1) and the merozoite surface protein 3-alpha (pvmsp3-alpha). RESULTS: Analysis of these three genetic markers revealed that P. vivax populations in Kolkata are highly diverse. A large number of distinguishable alleles were found from three genetic markers: 11 for pvcs, 35 for pvmsp1 and 37 for pvmsp3-alpha. These were, in general, randomly distributed amongst the isolates. Among the 151 isolates, 142 unique genotypes were detected the commonest genotype at a frequency of less than 2% (3/151). The overall rate of mixed genotype infections was 10.6%. CONCLUSION: These results indicate that the P. vivax parasite population is highly diverse in Kolkata, despite the low level of transmission. The genotyping protocols used in this study may be useful for differentiating re-infection from relapse and recrudescence in studies assessing of malarial drug efficacy in vivax malaria

Study on the Anatomical Variations of the Posterosuperior Bony Overhang of External Auditory Canal

To evaluate the extent of posterosuperior bony overhang required to be removed for proper exposure of the incudo-stapedial complex during stapes surgery. Whether an assessment can be made out about the extent of the posterosuperior bony overhang clinically or not. A prospective study. One hundred patients of Stapedial Otosclerosis were included in this study. The direction of the posterosuperior bony canal wall i.e. straight or sloping type was recorded in every patient. All the patients underwent stapedotomy operation under local anaesthesia. The amount of overhang of the posterosuperior bony canal wall required to be removed for adequate exposure of the incudo-stapedial complex during stapes surgery was recorded by using measured right-angled picks of different sizes in mm. The aim of this study is to find out the extent of posterosuperior bony overhang and to know whether the posterosuperior bony overhang is more in straight or sloping bony canal wall. Fifty-seven percent of our patients had a medially sloping posterosuperior bony canal wall and 43% had a straight canal wall, which was noted clinically before surgery. The extent of posterosuperior bony overhang was divided into 4 groups: Gr. A ≤2 mm, Gr. B 2–2.5 mm, Gr. C 2.5–3 mm, Gr. D ≥3 mm. There were 25 patients in Group A, 55 in Group B, 20 in Group C and none in Group D. So majority (i.e. 55%) patients belonged to Group B i.e. 2–2.5 mm. The posterosuperior bony overhang is more in those patients who had straight bony canal than those who had sloping bony canal. This may be clinically assessed and this observation is statistically significant (P < 0.001)

Patterns of allelic diversity in the Kolkata <i>P. vivax</i> population.

<p>1. Three antigenic and 8 microsatellite genetic loci.</p><p>2. He: heterozygosity.</p><p>3. The alleles were numbered and the number of the most commonly identified allele and the corresponding proportion (%) of all identified alleles are shown. When two are equal, both are shown.</p

<i>P.vivax</i> recurrent infections in Kolkata.

<p><i>P.vivax</i> recurrent infections in Kolkata.</p

The temporal pattern of the 47 recurrences of <i>Plasmodium vivax</i> malaria in 151 patients with acute vivax malaria in Kolkata following treatment with chloroquine +/− primaquine.

<p>The three treatment groups were pooled as there were no significant differences in recurrence proportions between them.</p