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Introduction to Viral Storms: Infectious Disease

Shivaprasad Sirimalla1, Sanjit Sah2,3,4, Uday Venkat Mateti1* and Allen Pinto1

1Department of Pharmacy Practice, NGSM Institute of Pharmaceutical Sciences (NGSMIPS), Nitte (Deemed to be University), Mangalore, Karnataka, India

2Department of Pediatrics, Dr. D. Y. Patil Medical College, Hospital and Research Centre, Dr. D. Y. Patil Vidyapeeth (Deemed-to-be-University), Pimpri, Pune, Maharashtra, India

3Department of Public Health Dentistry, Dr. D.Y. Patil Dental College and Hospital, Dr. D.Y. Patil Vidyapeeth (Deemed-to-be-University), Pune, Maharashtra, India

4Department of Medicine, Korea University, Seoul, South Korea

Abstract

Infectious diseases, caused by pathogenic microorganisms including bacteria, viruses, and fungi, continue to present significant challenges to global health. The emergence of highly virulent viruses in the twenty-first century has resulted in pandemics that have profoundly affected humans worldwide. Major pandemics and epidemics such as H1N1 influenza, severe acute respiratory syndrome, human immunodeficiency virus, and coronavirus disease have already afflicted humanity. Several factors contribute to the emergence and spread of these viral outbreaks, including environmental changes, urbanization, global travel, and biological factors such as viral mutations and host immune responses. For many infections, geographical and seasonal patterns are inherently linked to the climate, raising the possibility of using climate parameters as predictive indicators in disease early warning systems (EWS). Norovirus infection, a significant global problem, shows predictable seasonality, with activity peaks during the winter seasons and in cold-temperature places. The primary step to prevent the spread of infectious diseases is the early identification of diseases and following effective interventions to control the diseases, resulting in reduction of mortality and morbidity. Using climate parameters and EWS is effective in predicting the diseases and can prevent the huge spread of transmission of a disease. Public health measures such as isolating, quarantining, and controlling the border had helped in past events to control the disease spread and it maintained social structure. Analyzing the past events and current examples provides great understanding of different aspects of viral storms; it may help to combat future pandemics in terms of prevention and management.

Keywords: Infectious diseases, viral pandemics, norovirus, climate change, viral transmission, global health

1.1 Introduction to Infectious Disease

Infectious diseases have been a continuously major health concern in human history, which caused various pandemics that impacted human population in various ways such as the economy. There are various pathogens that cause these infectious diseases such as parasites, fungus, viruses, and bacteria, leading to continuous damage to human health globally. Research in the field of infectious disease explored the infection mechanism, host-pathogen interaction, disease spread, and prevention and control of disease. It is very essential to understand completely the dynamics of an infectious disease that changes in response to environment, social, and biological factors [1-3].

Infectious diseases can happen in a large range of severity such as mild and self-limiting, i.e., common cold. Some other infections can cause severe and life-threatening situations such as sepsis. Cytokine storm is one of the severe manifestations of infectious diseases. It is a huge and uncontrolled immune response of the host after an infection. The host's immune system releases a large amount of cytokines into the blood stream that causes inflammation and damage to the tissue and finally leads to organ failure. This unusual situation happens in severe infections such as COVID-19, influenza, etc., giving importance to the host's immune response in combating infections [4-6].

Infectious diseases significantly impacted global health and accounts for a considerable number of morbidity and mortality. It was much more in low- and middle-income countries which are having limited access to healthcare. Infectious diseases also burden the economic and social domains, saturating the healthcare system, causing financial collapse, and worsening social inequalities [7, 8].

Research has made significant progress and contributions in fighting infectious diseases. In the past, diseases like polio, smallpox, and measles were prevented by the invention of vaccines, which has been the most profound advancement and thereby saving millions of lives. The invention of antibiotics and its wide usage made new revolution for bacterial infection and thereby reduced significant mortality rates. Likewise, invention by the use of antiviral drugs has made transformations on the management of viral infections like HIV/AIDS and hepatitis. The medical advancement has significantly decreased the burden on countries caused by the infectious diseases, and this leads to improved quality of life and improved human lifespan [9, 10].

Nevertheless, the combat against infectious diseases is not yet finished. As the new emergence of infectious diseases arises, such as novel coronavirus like SARS-CoV-2 that causes COVID-19, it is still a problem to the health of mankind. The emergence of new diseases is due to various factors such as interaction of humans with wild animals, leading to zoonotic spillover in which deadly pathogens transfer from animals to humans. This event happens due to several factors like increased human-animal interaction, deforestation, and climate change. In most parts of the world, deadly old pathogens like tuberculosis and measles which are under control are again re-emerging as new mutant forms of viruses along with new infectious diseases [11, 12].

Along with newly emerging viruses, antimicrobial resistance (AMR) is another challenge to fight against infectious diseases. Misuse and overuse of antibiotics, antivirals, and antifungals have happened over a period of time, and these lead to the development of drug-resistant strains of these pathogenic microorganisms. AMR has been the major obstacle in fighting the infectious diseases. This may lead to problems in fighting very common infectious diseases and become untreatable, and thus small surgical infections and minor infections can become severe and life-threatening [13, 14].

Viruses face a variety of challenges in the process of emergence of infectious diseases. Viruses require a host's cells to grow, replicate, and transmit. They cannot live and reproduce outside of the hosts, and this nature of replication is different from other pathogenic microorganisms like bacteria. This nature of dependence of viruses leads to frequent mutations to sustain the host's response to a virus, and this causes the frequent emergence of new strains. For example, influenza virus goes through several genetic mutations and leads to seasonal outbreaks and sometimes pandemics whenever a new strain comes. Likewise, SARS-CoV 2 virus showed several mutations in the RNA genome, and it leads to the emergence of new variants showing their new virulent effects [15].

The spread of infectious diseases is based on several interconnected factors including human nature, climate changes, and a variety of characteristics of pathogenic microorganisms. There are several human nature or behavior, including urbanization, global travel, and population density, causing the greater transmission of virus across the globe. Likewise, climate changes causes the transmission of vector-borne diseases like malaria and dengue. Thus, it is very essential to consider these factors to prevent and manage infectious diseases effectively [3].

After the huge development of research and science, infectious diseases are still a major challenge in human health. Complete surveillance on public health and research in the field of infectious diseases still need to be developed and conducted as there is the emergence of new pathogenic microorganisms in the world, emergence of frequent mutant viruses, and increased AMR. Considering all of the factors like how a new infectious disease emerge and spreads along with understanding the pathogenic microorganisms and through a comprehensive, multidisciplinary approach can make us understand, manage, and prevent the disease effectively, and thereby it can decrease the disease impact on public health globally.

1.2 Virology: Overview of Virus, Virus Structure, Classification, Replication, and Transmission

1.2.1 Overview of the Virus

Viruses are acellular pathogenic microorganisms that cause infectious diseases. Unlike other pathogenic agents such as bacteria, fungi, etc., viruses require a host cell to survive, replicate, and transmit disease, as they lack a proper cellular mechanism to perform metabolic function on their own to replicate and spread the diseases. It will proliferate by taking access of the host's cell through infection [16, 17].

Basically, every virus has a genetic material, i.e., either DNA or RNA, to replicate into viral particles inside the host's cell. Since viruses are acellular, the genetic material will be enveloped inside the protein case called capsid. In certain conditions, the virus additionally enveloped inside the lipid case which is generally derived from the host's cell. The envelop is usually arranged with...