zoonoses

The global virome: The viruses have a global distribution, phylogenetic diversity and host specificity. They are obligate intracellular parasites with single- or double-stranded DNA or RNA genomes, and afflict bacteria, plants, animals and human population. The viral infection begins when surface proteins bind to receptor proteins on the host cell surface, followed by internalisation, replication and lysis. Further, trans-species interactions of viruses with bacteria, small eukaryotes and host are associated with various zoonotic viral diseases and disease progression. Virome interface and transmission: The cross-species transmission from their natural reservoir, usually mammalian or avian, hosts to infect human-being is a rare probability, but occurs leading to the zoonotic human viral infection. The factors like increased human settlements and encroachments, expanded travel and trade networks, altered wildlife and livestock practices, modernised and mass-farming practices, compromised ecosystems and habitat destruction, and global climate change have impact on the interactions between virome and its hosts and other species and act as drivers of trans-species viral spill-over and human transmission. Zoonotic viral diseases and epidemics: The zoonotic viruses have caused various deadly pandemics in human history. They can be further characterized as either newly emerging or re-emerging infectious diseases, caused by pathogens that historically have infected the same host species, but continue to appear in new locations or in drug-resistant forms, or reappear after apparent control or elimination. The prevalence of zoonoses underlines importance of the animal–human–ecosystem interface in disease transmission. The present COVID-19 infection has certain distinct features which suppress the host immune response and promote the disease potential. Treatment for epidemics like covid-19: It appears that certain nutraceuticals may provide relief in clinical symptoms to patients infected with encapsulated RNA viruses such as influenza and coronavirus. These nutraceuticals appear to reduce the inflammation in the lungs and help to boost type 1 interferon response to these viral infections. The human intestinal microbiota acting in tandem with the host’s defence and immune system, is vital for homeostasis and preservation of health. The integrity and balanced activity of the gut microbes is responsible for the protection from disease states including viral infections. Certain probiotics may help in improving the sensitivity and effectivity of immune system against viral infections. Currently, antiviral therapy is available only for a limited number of zoonotic viral infections. Because viruses are intracellular parasites, antiviral drugs are not able to deactivate or destroy the virus but can reduce the viral load by inhibiting replication and facilitating the host’s innate immune mechanisms to neutralize the virus. Conclusion: Lessons from recent viral epidemics - Considering that certain nutraceuticals have demonstrated antiviral effects in both clinical and animal studies, further studies are required to establish their therapeutic efficacy. The components of nutraceuticals such as luteolin, apigenin, quercetin and chlorogenic acid may be useful for developing a combo-therapy. The use of probiotics to enhance immunity and immune response against viral infections is a novel possibility. The available antiviral therapy is inefficient in deactivating or destroying the infecting viruses, may help in reducing the viral load by inhibiting replication. The novel efficient antiviral agents are being explored.

In 2013, the World Health Organization (WHO) reported that small, pet turtles had caused multistate Salmonella outbreaks in the United States, from where small turtles were subsequently exported into the Republic of Korea. We investigated cases of salmonellosis in South Korea associated with domestic small turtles and analysed genetic characteristics of Salmonella isolates in commercially-available small turtles. We traced six Salmonella serovars, known to have caused human infection in the United States (S. Sandiego, S. Pomona, S. Poona, S. Newport, I 4,(5),12:i:-, and S. Typhimurium), in isolates from suspected Salmonella infection cases in Korea from 2006 to 2015. Additionally, we conducted a pilot study of isolates from small turtles being sold in Korean markets, and performed molecular genetic analysis on the identified strains. S. Pomona was identified in one Salmonella infection case, while all strains isolated from small turtles belonged to either subspecies I (enterica, n = 10, 71.4%) or subspecies IIIb (diarizonae, n = 4, 28.6%). Two serovars (S. Pomona and S. Sandiego) that were highly associated with turtle-to-human transmission were identified with 100% homology to human isolates. Previous to this study, turtle-associated human S. Pomona infections were not well reported in Korea. We report Salmonella infection in small turtles in Korea, and confirm that small turtles should be considered the first infectious agent in S. Pomona infection. We therefore suggest quarantine measures for importing small turtles be enhanced in Korea.

Fish-borne parasitic zoonoses are primarily found in people living in developing and underdeveloped countries. The parasites that cause such zoonoses like Trichinella and Taenia are well-known in developed nations, but few people are familiar with fish-borne parasitic zoonoses, which are largely caused by helminths and protozoans. In general, parasitic zoonoses transmitted by fish are rarely life-threatening, although cases and reports of such infestations have increased over the world. The list of parasitic organisms is extensive. This article attempts to provide a complete overview of the many fish-borne parasites that can cause zoonosis among humans and animals alike.