Hundreds of thousands of adults and children are sickened every winter by concurrent outbreaks of respiratory viruses. Acute respiratory viral infections (ARIs) are the leading cause of morbidity and mortality from infectious diseases in the world. Almost four million people die from ARIs each year, with 98% of these deaths due to lower respiratory tract infections (
20).
Acute respiratory viral infections are the leading cause of morbidity and mortality from infectious diseases worldwide, especially affecting the younger and the elderly in low- and middle-income countries. These infections, typically caused by viruses [influenza virus, parainfluenza type 1 and 2, respiratory syncytial virus, Middle East respiratory syndrome related-coronavirus (MERS-CoV, SARS-CoV, novel coronavirus disease 2019 [COVID-19], etc.) or combined viral cum bacterial infections can spread rapidly and can be infectious. However, the mode of transmissions area constantly evolving, existing data suggest that droplet infections are the major mode of transmission in ARIs. But certain pathogens may also transmit via touch or infectious aerosols in specific circumstances (
20,
21).
In modern medicine, interventions to prevent and monitor infection (IPC) in healthcare settings are of vital importance to patient safety, healthcare personnel, and the habitat, and to mitigate the risk of the infectious disease locally and worldwide. The management of ARIs is no exception to this. Since many ARI symptoms are frequent and non-specific, it can be difficult and confusing to apply IPC measures for ARIs in areas where healthcare resources are restricted. In these areas, screening procedures, early diagnosis, quarantine procedures, rapidly creating and placing patients in isolation, and proper aeration could be the steps to control and mitigate the spread of the infectious agent. These recommendations reflect an update to the interim guidance of the World Health Organization (WHO) infection prevention and control in health care of infectious and pandemic-prone acute respiratory diseases, 2007 (
21,
22). They also provide emergency advice for confirmed, possible, or suspected pandemic cases (H1N) 2009 virus infection and influenza-like disease as provided by the WHO for prevention and control of infectious diseases in 2009 (
21).
Commonly, respiratory viruses involve the mucosa of the respiratory tract (upper and lower). Influenza is commonly manifested by cold, cough, croup, bronchiolitis, and pneumonia. On the other hand, rhinovirus leads to the typical manifestation of common cold, while respiratory syncytial virus (RSV) mostly leads to bronchiolitis which may progress to ARDS (acute respiratory distress syndrome) (
20,
21).
The extent of viral respiratory illness varies widely; in older patients and children, serious illness is more likely. Morbidity may result directly from a viral infection or maybe indirect due to exacerbation of underlying cardiopulmonary or lung conditions, paranasal sinus, or bacterial superinfection in the middle ear (
21).
Mostly respiratory infections epidemics begin during October and peak till February. The normal trend for odd-numbered epidemiological years is for parainfluenza type 1 virus, which occurs during fall or at the beginning of October, followed by parainfluenza type 2. The later causes lower respiratory tract infection in fewer cases. Influenza virus starts January, and peaks in February while RSV starts during November and outbreak between December and January. In general, the type 3 parainfluenza virus accompanies the influenza epidemic and is widespread during November and February (
20,
22).
Acute respiratory disease outbreaks are common and can occur in many settings (e.g., households, nursing homes, army barracks). It can require different treatments, infection prevention procedures and other preventive measures to manage outbreaks. Research into the clinical and epidemiological characteristics, as well as the etiology of outbreaks, is therefore specifically relevant to public health. To rule out emerging health risks, investigating serious unexplained respiratory outbreaks may be of particular importance (
21,
22).
The etiology of many acute respiratory diseases can remain unknown, despite continuing efforts. Investigating unexplained respiratory outbreaks may classify infectious agents that involve specific control and prevention approaches (e.g., pulmonary hantavirus syndrome, SARS, COVID-19); however, are outbreak investigations for previously established etiologies are equally relevant. This mechanism can be improved by concrete efforts to Alert clinicians to recognize and record cases and clusters of unidentified infectious diseases. Prepare health departments for those clusters to be investigated (
21,
22).
On 11 March 2020, the WHO announced the outbreak of COVID-19 as a pandemic and reinforced an appeal for countries to take urgent action and increase response to treat, diagnose and minimize spread to save lives for people (
23). Coronaviruses (CoV) are a wide family of viruses which lead to diseases varying from cold or flu to more serious illnesses, such as SARS-CoV, MERS-CoV, and COVID-19. Pneumonia of an unknown origin found in Wuhan, China was first confirmed on novel coronavirus infection (nCoV) to the WHO Country Office in China on 31 December 2019. On 20 March 2020, there were 209,839 confirmed cases, 8,778 confirmed deaths in 169 countries, areas, or territories of the world (
24). The virus is believed to spread mainly from one person to another. People who are in close contact within six feet and breathing in the air, coughed and sneezed by an infected individual in close contact. The droplets from an infected person may enter other people’s respiratory tract through the nose or mouth. Touching the infected surface and goods with the virus may transmit infections in some cases (
25,
26).
The COVID-19 is a new strain that was identified in 2019 and not established in humans beforehand (
24). A new coronavirus now called SARS-CoV-2 (the official name for the coronavirus that causes the COVID-19 disease) causes the COVID-19 pandemic. This coronavirus is closely related, but differs from the coronavirus that triggered the SARS outbreak in 2002 - 2003. Coronaviruses are zoonotic, which means that they are spread between animals and humans. Coronaviruses are prevalent and account for up to 25% of “common colds”. Certain coronaviruses, such as those responsible for SARS and MERS, contribute to much more severe diseases. Various species of bats serve as the natural host for coronaviruses, which break out as zoonotic epidemics periodically into human populations (
27,
28).
Respiratory symptoms, fever, cough, shortness of breath, and trouble breathing are typical signs of infection. For more serious cases, pneumonia, extreme acute respiratory syndrome, kidney failure, and even death may result from infection. Although COVID-19 symptoms frequently mimic influenza symptoms, including fever and cough, COVID-19 tends to be even more infectious than flu and has a case fatality rate that can be up to 10 times higher than influenza. While the crude case fatality rate appears to be 3.96 percent, based solely on reported numbers of cases and deaths, the actual risk of COVID-19 death is unclear as testing for SARS-CoV-2 infection and supporting COVID-19 care varies widely around the world (
25,
27). Actual death rates in South Korea are 0.9% and vary tremendously such as 7.3% in Italy. Although the reasons for these large differences are uncertain in case of fatality rates, what is apparent is that older age (particularly patients over 70 years of age) and underlying medical conditions, such as hypertension and cardiovascular and pulmonary diseases, significantly increase the risk of mortality. Conversely, unlike the 2009 H1N1 swine flu outbreak, rates of a symptomatic infection, and as a result, a serious disease in children and adolescents are substantially lower with COVID-19 compared with older adults (
27,
28).
A total of 195 COVID-19 cases (163 Indians and 32 foreign nationals) were registered in 20 States/Union territories of India as of 20 March 2020 (9:00 AM). These included 19 people who were cured/discharged, one person who migrated, and four deaths were reported. Hospital isolation of the contacts from all reported incidents, tracing and home quarantine are continuing (
23).
The preventive strategy is the same as any of the respiratory viral infections like influenza, including social distance, regular hand washing, and avoiding touching eyes, nose, and mouth. Those who have had close contact with a person with confirmed COVID-19 will have 14 days of self-quarantine (the average duration of incubation is 5 - 7 days, but some cases occurred as long as 12 - 14 days after exposure) (
27).