Domestic dogs as reservoir hosts for Leishmania donovani in the southernmost Western Ghats in India.

The peripheral blood samples from domestic dogs (n=47) and wild rats (n=25) in the Kani Tribe settlements, located southernmost part of the Western Ghats, Thiruvananthapuram district, Kerala, India were examined for Leishmania infection. This area is known for cases of leishmaniasis with cutaneous manifestations and sandfly abundance. The tribes domesticate dogs to protect them from untoward activities of wild animals. Leishmania donovani parasite DNA was detected only from 6.4% (n=3) of the blood samples collected from the domestic dogs by amplification of the diagnostic kinetoplast mini-circle DNA and PCR-RFLP analysis of the UTR region of heat shock protein 70 (hsp70) gene. None of the blood samples collected from rats was positive. Through sequencing, L. donovani infection among dogs was confirmed. The DNA sequences generated for hsp70 were deposited with the GenBank. The GenBank accession numbers of these samples are KR905363, KR905364 and KR905365 for hsp70 genes. The results indicated that the DNA isolates from dog blood samples matched precisely with that of our earlier isolates from skin lesions of Kani tribes and also from P. argentipes vector. Thus, the role of dogs as reservoirs for L. donovani parasite in the Kani tribe settlements is confirmed.

DNA Barcodes indicate members of the Anopheles fluviatilis (Diptera: Culicidae) species complex to be conspecific in India.

Anopheles fluviatilis, a major vector of malaria in India has been described as a complex of three sibling species members, named as S, T and U, based on variations in chromosomal inversions. Also, ribosomal DNA markers (repetitive Internal Transcribed Spacer 2 (ITS2) and 28S D3 region) were described to differentiate these three sibling species members. However, controversies prevail on the genetic isolation status of these cryptic species. Hence, we evaluated this taxonomic incongruence employing DNA barcoding, the well established methodology for species identification, using 60 An. fluviatilis sensu lato specimens, collected from two malaria endemic eastern states of India. These specimens were also subjected to sibling species characterization by ITS2 and D3 DNA markers. The former marker identified 31 specimens among these as An. fluviatilis S and 21 as An. fluviatilis T. Eight specimens amplified DNA fragments specific for both S and T. The D3 marker characterized 39 specimens belonging to species S and 21 to species T. Neither marker identified species U. Neighbor Joining analysis of mitochondrial cytochrome c oxidase gene 1 sequences (the DNA barcode) categorized all the 60 specimens into a single operational taxonomic unit, their Kimura 2 parameter (K2P) genetic variability being only 0.8%. The genetic differentiation (FST ) and gene flow (Nm ) estimates were 0.00799 and 62.07, respectively, indicating these two 'species' (S & T) as genetically con-specific intermixing populations with negligible genetic differentiation. Earlier investigations have refuted the existence of species U. Also, this study demonstrated that An. fluviatilis and the closely related An. minimus could be taxonomically differentiated by the DNA Barcode approach (K2P = 5.0%).

Diagnostic value of C-reactive protein in suspected acute appendicitis--a prospective case control study.

AIM: To find out the Sensitivity, Specificity and Predictive value of C-reactive protein in the diagnosis of acute appendicitis. MATERIALS AND METHODS: Hundred patients undergoing emergency appendicectomy were cases and thirty patients undergoing interval appendicectomy during the same period were controls. Creactive protein was measured pre-operatively. RESULTS: CRP was reactive in 89% of cases and 3 of 30 controls (P = 0). Among the thirteen complicated cases, two had a CRP reactivity of 1.2 mg/dl, eight had 2.4 mg/dl and three had 3.6 mg/dl. In the uncomplicated cases, forty nine were reactive at 1.2 mg/dl, twenty six at 2.4 mg/dl and one at 3.6 mg/dl (P = 0.0009). In histopathologically inflamed appendix, reactivity was 94.4% and in normal appendix reactivity was 40% (P = 0.00007). CRP positivity had a sensitivity of 94.4% (CI 89.9-98.9) and a positive predictive value of 95.5% (CI 91.4-99.6). CRP reactivity and leucocytosis if combined, the sensitivity, specificity, PPV and NPV were 85%, 100%, 100% and 81% respectively. Threshold for CRP reactivity if raised to 2.4 mg/dl, the sensitivity, specificity, PPV and NPV are 42%, 100%, 100% and 16% respectively. CONCLUSION: CRP estimation is a good 'rule-in' test and not-so-good 'rule-out' test to diagnose acute appendicitis.

Genetic variability of the human filarial parasite, Wuchereria bancrofti in South India.

The genetic variability of the lymphatic filarial parasite Wuchereria bancrofti, from three localities (one urban and two rural areas) in southern India, endemic for filariasis was studied using random amplified polymorphic DNA (RAPD) markers. The RAPD profiles were generated for 21 parasite populations (7 populations from each area), using a 10-mer random primer. The analysis of profiles indicated the existence of considerable genetic variability among parasite populations. The Nei's gene diversity between the individual populations in the 2 areas (one urban and another rural) was comparatively greater (0.3372+/-0.1462 & 0.2830+/-0.1764) than that of populations in another village (0.0490+/-0.1373). The greater genetic diversity among the former areas may be due to human migration, endemicity for long time and drug (diethyl-carbamazine citrate) pressure unlike the populations of latter village where the filariasis is relatively a recent introduction and which was never under active chemotherapy. The Nei's genetic distance was estimated and the phylogenetic tree was constructed using 'UPGMA'. These analyses indicated the prevalence of at least two genetically distinct clusters, among the populations studied, their maximum genetic distance being 0.2444. The finding of two genetic 'variants' of W. bancrofti, in the present study, may have important implications in filariasis epidemiology and control/elimination programmes.