Bluetongue (BT) is an arthropod-borne viral disease mostly of sheep. Bluetongue virus (BTV) is a segmented double-stranded RNA virus belonging to the genus Orbivirus of family Reoviridae and is transmitted by midges belonging to Culicoides spp. The disease is endemic in the tropics and subtropics, and the incidence is high in southern India. Twenty-six serotypes of BTV have been reported worldwide. Although most of the serotypes have been reported in India, information regarding currently circulating serotypes is essential to develop control programs. Both serological assays and nucleic acid-based assays have been used for typing BTV. Segment 2, which codes for the outer capsid protein VP2, is the target for PCR-based typing; however, the VP2 sequence diversity among viruses belonging to the same serotype but isolated from different geographical areas makes it essential to develop geographical based reagents. In this study, reverse transcription PCR was developed based on sequences of Indian isolates of BTV (serotypes 1, 2, 9, 10, 12, 16, 21 and 23), and this was applied to type 52 isolates obtained during the last decade. It was found that multiple serotypes circulate, with involvement of more than one serotype infecting individual animals and herds over a period in a given area. Detection of circulating serotypes and estimation of herd immunity against different serotypes of BTV may provide important information for predicting the distribution of these serotypes and inclusion of serotypes in vaccines.

Bluetongue (BT) is a Culicoides-borne disease caused by several serotypes of bluetongue virus (BTV). Similar to other insect-borne viral diseases, distribution of BT is limited to distribution of Culicoides species competent to transmit BTV. In the tropics, vector activity is almost year long, and hence, the disease is endemic, with the circulation of several serotypes of BTV, whereas in temperate areas, seasonal incursions of a limited number of serotypes of BTV from neighbouring tropical areas are observed. Although BTV is endemic in all the three major tropical regions (parts of Africa, America and Asia) of the world, the distribution of serotypes is not alike. Apart from serological diversity, geography-based diversity of BTV genome has been observed, and this is the basis for proposal of topotypes. However, evolution of these topotypes is not well understood. In this study, we report the isolation and characterization of several BTV-4 isolates from India. These isolates are distinct from BTV-4 isolates from other geographical regions. Analysis of available BTV seg-2 sequences indicated that the Australasian BTV-4 diverged from African viruses around 3,500 years ago, whereas the American viruses diverged relatively recently (1,684 CE). Unlike Australasia and America, BTV-4 strains of the Mediterranean area evolved through several independent incursions. We speculate that independent evolution of BTV in different geographical areas over long periods of time might have led to the diversity observed in the current virus population.

Studies on population dynamics of thrips on tomato crop were carried out during two consecutive kharif seasons (2016 and 2017). The observations viz., number of adult thrips and associated GBNV disease and natural enemies were recorded at weekly intervals. The results revealed that, thrips activity found throughout the cropping period. The population of thrips was increased gradually from first week after transplanting to flowering and fruit development stage and later it was decreased as crop matures. During 2015-16 kharif crop, maximum thrips population (8.40 thrips/three leaves) was observed during the last week of November and first week of December. Similarly during 2016-17 kharif crop, maximum thrips population (10.30 thrips/three leaves) was observed during third and last week of December. The population of zoopytophagous miridbug, Nesidiocoris tenuis Reuter was found linear with the population of thrips during both the seasons. The percent disease incidence of GBNV on tomato crop was linier with the thrips population during both the seasons. The cumulative disease incidence was 42.50 % and 45.10 % during first and second seasons respectively. Correlation studies indicated that, minimum temperature, rainfall, rainy days and evening relative humidity were found significant negative correlation with the thrips population, while sunshine hours and morning relative humidity found significant positive correlation with the thrips population.

Dengue is an endemic and epidemic disease of the tropical and subtropical regions. Between September & October 2012, there was an established outbreak of dengue in Hoskote, near Bangalore. Dengue results in serositis, which can be imaged by ultrasonography. OBJECTIVE To correlate the USG findings with the serological tests in paediatric and adult patients. MATERIALS AND METHODS 110 patients with clinical suspicion of dengue fever during the above period underwent serological tests-NS1, IgM and IgG and were evaluated with USG of the abdomen and thorax. The USG findings were correlated with serological tests. RESULTS 67 Patients were seropositive, 43 were seronegative. The USG findings in seropositive paediatric patients (n=32) and adult patients (n=35) respectively were gall bladder (GB) wall edema-27 & 31, hepatomegaly-12 &14, ascites-16 & 12, splenomegaly-15 & 9, right pleural effusion-14 & 13, left and bilateral pleural effusion-7 & 5. CONCLUSION In our study GB wall edema significantly correlated with seropositivity (p value=0.032). Thus ultrasound is an efficient screening tool in a case of dengue outbreak.

Any serotypes of dengue virus (DENV), which are DENV1-4, may lead to dengue infections.DENV spread via mosquito vector, primarily Aedes aegypti and Aedes albopictus mosquitoes.DENV is one of the most prevalent viruses, which is causing dengue fever (DF), dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) that may be fatal. determined. An effective vaccine against DENV infections should be a tetravalent vaccine that can counter-attack all four serotypes. Therefore, E glycoproteins of all four serotypes was chosen to be analyzed. Conserved regions were found in 100 sequences of each DENV serotype.Multiple sequence alignments was done to obtain consensus sequence. Multiple bioinformatics tools were used for prediction of B-cell and T-cell epitopes based on antigenicity, hydrophilicity, beta-turn, flexibility and surface accessibility. Secondary and tertiary structures of E glycoprotein for each serotypes were predicted and aligned. Complete analysis showed that predicted epitopes were located within conserved regions, and DENV2 showed the highest percentage of mutation rates and had the highest similarity to DENV1, DENV3 and DENV4.

BACKGROUND Herpes genitalis (HG) is a sexually transmitted infection of great public health importance. HSV-2 is the major cause of the infection in more than 80% of such cases. Many patients with other sexually transmitted infections (STIs) without clinical signs and symptoms of HG also were found to have serological positivity for HSV-2 on serological screening for STIs. Objective-To study the seroprevalence of HSV-2 antibodies in patients with HG, 'Other STIs' and a cross section of the general population in the STI clinic attached to the Department of Dermatology and Venereology of Medical College, Thiruvananthapuram, one of the biggest tertiary care centre in South India. MATERIALS AND METHODS 51 patients who attended the clinic with various STIs and an equal number of individuals of the sexually active age group as a comparison group were screened for HSV-2 IgM and IgG antibodies tested by ELISA and the titres were recorded. Statistical analysis was done by an appropriate computer software and Chi-square test as a non-parametric test. RESULTS HSV-2 IgM or IgG was positive in 58.8% of STI patients, 95.2% of HG cases, 33.33% of patients with 'other STIs' and 27.45% of individuals of the comparison group representing the general population.

No abstract

No abstract