வைராலஜி: தற்போதைய ஆராய்ச்சி

Many viruses trigger innate and adaptive immune responses and must circumvent the negative consequences to successfully establish infection in their hosts. Human Cytomegalovirus (HCMV) is no exception, and devotes a significant portion of its coding capacity to genes involved in immune evasion. Activation of the NFκB signalling pathway by viral binding and entry results in induction of antiviral and pro-inflammatory genes that have significant negative effects on HCMV infection. However, NFκB signalling stimulates transcription from the Major Immediate Early Promoter (MIEP) and pro-inflammatory signalling is crucial for cellular differentiation and viral reactivation from latency. Accordingly, HCMV encodes proteins that act to both stimulate and inhibit the NFκB signalling pathway. In this Review we will highlight the complex interactions between HCMV and NFκB, discussing the known agonists and antagonists encoded by the virus and suggest why manipulation of the pathway may be critical for both lytic and latent infections.

Treatment of Lycopersicon esculentum and Lagenaria siceraria plants, with phytoproteins, isolated from roots of Boerhaavia diffusa and leaves of Clerodendrum aculeatum, mixed separately with bio enhancer, could significantly prevent the infection and spread of tomato mosaic/tomato leaf curl virus. It was revealed that the potential of CA phytoprotein mediated induction of resistance was increased, in plants treated with CA phytoprotein along with bio enhancer M9 and M3. The CA phytoprotein mixed together with M9 was found to be more efficacious in protecting crops against viruses than Clerodendrum aculeatum alone. On the other hand, potential of Boerhaavia diffusa phytoprotein was also enhanced by the addition of bio enhancers M9 and M3, in inducing systemic resistance in Lycopersicon esculentum and Lagenaria siceraria plants, against natural infection of tomato mosaic/tomato leaf curl or cucumber mosaic virus respectively. Higher degree of modified systemic resistance was induced by BD phytoprotein, mixed with bio enhancers as compared to BD phytoprotein alone. However, BD phytoprotein in combination with M9 was found to be more effective than BD alone or BD with M3.

The Zika virus outbreak in 2015 posed a serious public health threat, particularly in view of its association with congenital abnormalities. We point out that this outbreak may have been linked to a systematic increase in the flux of cosmic rays and a general decline of sunspot activity that has been observed over the period 2010-2017. Future surveillance efforts should in our view take account of such events.

Introduction: As the Global Polio Eradication Initiative (GPEI) moves towards achieving the goal of polio eradication, environmental surveillance which investigates polio virus in sewage or wastewater, plays a major role in providing evidence for certification of polio-free status. Many countries in the AFRO region have added environmental surveillance to acute flaccid paralysis (AFP) surveillance but Ghana is yet to adopt and conduct environmental surveillance as a routine national activity. Here, we piloted environmental surveillance from September to December 2016 to determine silent circulation of poliovirus in some districts within Greater Accra and Eastern regions.

Objective: The study aimed to test national capacity and preparedness to undertake environmental surveillance as part of routine national surveillance activity for poliovirus.

Methods: Sewage samples collected from six selected sites within two regions were processed by grab method according to World Health Organization (WHO) guidelines on environmental surveillance. The samples were concentrated and inoculated on RD and L20B cell lines for virus isolation. Virus isolates were subjected to real-time PCR and non-polio enterovirus (NPEVs) typing.

Results: From a total of 36 sewage samples collected from the six sites, 7 (19.4%) were positive on cell lines. Of these positives, 6 (85.7%) showed growth on RD cells only and 1(14.2%) showed growth on both RD and L20B. The isolates were identified as one Coxsackie virus A 16 belonging to human enterovirus (HEV) A group, two Echovirus 6 and one each of Echovirus 13 and Echovirus 29 of HEV B, and Coxsackie virus 24 of HEV C.

Conclusion: No wild poliovirus transmission was detected in the study samples however, 7 NPEVs were isolated from 50% of the sites. Although the study in Ghana was not geographically representative, results were consistent with the enteroviruses distribution in AFP cases in the country. Our findings also indicated that environmental surveillance is feasible in Ghana and can be implemented as routine national surveillance program based on available national capacity and experience.