Cytopathic effect of PPR vaccine virus strains in Vero cells

The present study describes the cytopathic effect of two different Peste des petits ruminants (PPR) vaccine virus strains presently being used in the country, in vero cells. The cytopathic effect (CPE) was visible from 4th day post infection in Sungri vaccine virus strain where as Arasur vaccine virus strain showed CPE, 36-48 hr post infection. With both vaccine virus strains the CPE in vero cells showed initial cell rounding, aggregation and syncytial development. The generalized CPE was noticed by 6th day in Sungri and by 96 hrs post infection in Arasur strain. However complete detachment of the cell monolayer was observed in Arasur strain by 120 hr, post infection. Infected coverslip cultures stained with H & E and May & Grunwald’s Giemsa showed cell vaculation, cytoplasmic extension and syncytia comprising of five to six nuclei. Acidophilic intracytoplasmic and intranuclear inclusion bodies were also observed. Titers, HA activity and detection by s-ELISA of both the vaccine virus strains are also compared. [Vet. World 2009; 2(3.000): 93-94

PCR based confirmation of sheeppox vaccine virus

[Vet World 2010; 3(4.000): 160-

Change in Dengue and Japanese Encephalitis Seroprevalence Rates in Sri Lanka.

Sri Lanka has been affected by epidemics of dengue infections for many decades and the incidence and severity of dengue infections have been rising each year. Therefore, we investigated the age stratified seroprevalence of dengue infections in order to facilitate future dengue vaccine strategies. In addition, since the symptomatic dengue infections have increased during the past few decades, we also investigated the possible association with Japanese Encephalitis Virus (JEV) antibody seropositivity with symptomatic dengue in a community cohort in Sri Lanka.1689 healthy individuals who were attending a primary health care facility were recruited. Dengue and JEV antibody status was determined in all individuals and JEV vaccination status was recorded.1152/1689 (68.2%) individuals were seropositive for dengue and only 133/1152 (11.5%) of them had been hospitalized to due to dengue. A significant and positive correlation was observed for dengue antibody seropositivity and age in children (Spearmans R = 0.84, p = 0.002) and in adults (Spearmans R = 0.96, p = 0.004). We observed a significant rise in the age stratified seroprevalence rates in children over a period of 12 years. For instance, in year 2003 the annual seroconversion rate was 1.5% per annum, which had risen to 3.79% per annum by 2014. We also found that both adults (p<0.001) and in children (p = 0.03) who were hospitalized due to dengue were more likely to be seropositive for JEV antibodies. However, 244 (91.4%) of adults who were seropositive for JEV had not had the JEV vaccine.Dengue seroprevalence rates have risen significantly over the last 12 years in Sri Lanka, possibly due to increased transmission. As individuals who were hospitalized due to dengue were more likely to be seropositive for JEV, the possibility of cross-reactive assays and/or of JEV infection on immunity to the DENV and clinical disease severity should be further investigated

Seroprevalence of dengue infections.

<p>A: Age stratified seroprevalence of DENV-specific antibodies in children. B: Age stratified seroprevalence of DENV-specific antibodies in adults.</p

Association of JEV antibody optic density (OD) values with DENV antibody OD values.

<p>4A: Correlation of JEV IgG antibody OD values and DENV IgG OD values in individuals who had mild/asymptomatic dengue. 4B: Correlation of JEV IgG antibody OD values and DENV IgG OD values in individuals who were hospitalized due to dengue.</p