Assessment of population genetic structure in the arbovirus vector midge, Culicoides brevitarsis (Diptera Ceratopogonidae), using multi-locus DNA microsatellites

Bluetongue virus (BTV) is a major pathogen of ruminants that is transmitted by biting midges (Culicoides spp.). Australian BTV serotypes have origins in Asia and are distributed across the continent into two distinct episystems, one in the north and another in the east. Culicoides brevitarsis is the major vector of BTV in Australia and is distributed across the entire geographic range of the virus. Here, we describe the isolation and use of DNA microsatellites and gauge their ability to determine population genetic connectivity of C. brevitarsis within Australia and with countries to the north. Eleven DNA microsatellite markers were isolated using a novel genomic enrichment method and identified as useful for genetic analyses of sampled populations in Australia, northern Papua New Guinea (PNG) and Timor-Leste. Significant (P < 0.05) population genetic subdivision was observed between all paired regions, though the highest levels of genetic sub-division involved pair-wise tests with PNG (PNG vs. Australia (F-ST = 0.120) and PNG vs. Timor-Leste (F-ST = 0.095)). Analysis of multi-locus allelic distributions using STRUCTURE identified a most probable two-cluster population model, which separated PNG specimens from a cluster containing specimens from Timor-Leste and Australia. The source of incursions of this species in Australia is more likely to be Timor-Leste than PNG. Future incursions of BTV positive C. brevitarsis into Australia may be genetically identified to their source populations using these microsatellite loci. The vector's panmictic genetic structure within Australia cannot explain the differential geographic distribution of BTV serotypes

Assessment of risk patterns in cancer of the cervix: a comparison between greater Bombay and Western countries

In order to identify the high-risk groups in the community, a retrospective study of 503 women with histologically proved invasive carcinoma of the uterine cervix was undertaken and the results were compared with a similar appraisal of an equal number of controls closely matched for age, religion and income, in order to examine certain risk factors suspected of being of aetiological importance in patients with cervical cancer. We have sought to estimate the effects of parity, and of age at first marriage, first delivery and last delivery. The highest risk was observed in women who had undergone several pregnancies early in life. It is interesting to note that multiparity was one of the important risk factors in Bombay women, in contrast with the situation reported in Western countries