Swine flu: A threat to human health

Archives on Veterinary Science and Technology

The world is facing challenges from both new and re-emerging diseases and Influenza virus is one of the main causes of such diseases. The virus has the ability to mutate into a form that spreads efficiently among animals and humans. Swine influenza is a highly contagious and economically important disease of pigs. It is caused by type influenza viruses with main subtypes of H1N1, H1N2, H3N2 and H3N1. These are the main subtypes in endemic areas in pig populations. Human and avian influenza viruses can infect pigs and can give rise to novel reassortants. The virus enters in to the respiratory tract through different routes and attaches to the epithelial cells on the lining of the tract and replicates. Replication of the virus and action of immune cells together disrupts the cells on the lining of the respiratory tract. The disease has short incubation period with clinical signs of fever, lethargy, anorexia, weight loss, and coughing, sneezing, nasal and ocular discharge, conjunctivitis and labored breathing. Influenza A viruses infects a large variety of animal species including humans, pigs, horses, sea mammals and birds. Transmission of the virus from pigs to humans is not common. People with regular exposure to pigs are at increased risk of swine flu infection. Swine flu rarely passes from human to human. Symptoms of zoonotic swine flu in humans are in general, namely chills, fever, sore throat, muscle pains, severe headache, coughing, weakness and discomfort. The Centers of Disease Control and Prevention recommends real time polymerase chain reaction as the method of choice for diagnosing H1N1. Prevention of swine influenza has three components: prevention in swine, prevention of transmission to humans, and prevention of its spread among humans. If a person becomes sick with swine flu, antiviral drugs used in human influenza treatment are not generally administered to swine, but Antibiotics may be used to control secondary infections.

Systematic Reviews in Pharmacy, 2011

2010

World Journal of Pharmaceutical Research

This review discuss about viral infection commonly referred to as "swine flu" which has been reported to spread from one person to another by direct or indirect physical contact. In the past, transmission was limited but now days; transmission of this virus is rapid as it is spreading through air. Influenza A virus has been circulating worldwide resulting serious illness and deaths globally. This cross species infections (from swine flu virus to man and human flu virus to pigs) have found in local areas and did not cause severe infections in either pigs or humans. However, this cross-species found to have the potential to change. Investigators named it as "swine flu" strain. It was first time seen in Mexico, and termed novel H1N1 flu since it was mainly found infecting people and exhibits two main surface antigens, H1 (hemagglutinin type 1) and N1 (neuraminidase type1). In India, swine flu virus that speeded since mid of December, 2014 shows amino acid mutations. More than 33,761 people are infected by H1N1 virus in India and around 2,035 of infected people died in March, 2015 reportedly. This review includes symptom, history, transmission, preventions and treatment, current status in India. KEYWORD: Swine flu, Influenza H1N1 virus, Influenza A virus, current status is India.

Lung India, 2011

On April 15 and April 17, 2009, the Centers for Disease Control and Prevention [3] (CDC) identified two cases of human infection with a swine-origin influenza A (H1N1) virus. The World Organization for Animal Health reports [3] that Swine Influenza strain has not been isolated in pigs. [4] This strain can be transmitted from human to human [5] and causes the normal symptoms of influenza. [6] Basically these viruses causing pig's flue are classified as influenza A, B, and C. Transmission mainly occurs between pigs and pigs and humans. The viruses are 80-120 nm in diameter. [7] Of the three genera of influenza viruses that cause human flu, two also cause influenza in pigs, with influenza virus A being common in pigs and influenza virus C being rare. [8] Influenza virus B has not been reported in pigs. Within influenza virus A and C, the strains found in pigs and humans are largely distinct, although due to reassortment America, Europe (including UK, Sweden, and Italy), Kenya, Mainland China, Taiwan, Japan, and other parts of eastern Asia and in various parts of India. In humans, the symptoms of swine flu are similar to those of influenza namely chills, fever, sore throat, muscle pains, severe headache, coughing, weakness, and general discomfort. WHO declares on June 11, 2009, that H1N1 (Swine-influenza A) is pandemic. There have been nearly 30,000 confirmed H1N1 cases across 74 countries. The reports have shown sharp increase in the number of infections reported in recent days from Chile, Japan, and the UK, and other parts of the world, with the most dramatic increase recorded in Australia where more than 1200 cases were reported in a very short duration. As per the latest report of the Ministry of Health and Family Welfare, death from swine flu has reached to 1235. Around 12,3397 people have been tested in India as on February 1, 2010. In India, 23.3% of people who have tested for swine flu are found suffering from swine flu. Also around 4% of people who have tested positive for swine flu have died and could not be saved in India. The New York Times has reported that this is the first flu for being pandemic in the last 41 years. This article enlightens the brief review about the swine influenza virus, its modes of spread, and prevention measures. The aim of this article is to bring awareness in general and know the consequences of the infection.

Indian Journal of Microbiology, 2009

The 2009 H1N1 pandemic has slowed down its spread after initial speed of transmission. The conventional swine infl uenza H1N1 virus (SIV) in pig populations worldwide needs to be differentiated from pandemic H1N1 infl uenza virus, however it is also essential to know about the exact role of pigs in the spread and mutations taking place in pig-to-pig transmission. The present paper reviews epidemiological features of classical SIV and its differentiation with pandemic infl uenza.

Cold Spring Harbor Perspectives in Medicine

Influenza A viruses (IAVs) are the causative agents of one of the most important viral respiratory diseases in pigs and humans. Human and swine IAV are prone to interspecies transmission, leading to regular incursions from human to pig and vice versa. This bidirectional transmission of IAV has heavily influenced the evolutionary history of IAV in both species. Transmission of distinct human seasonal lineages to pigs, followed by sustained within-host transmission and rapid adaptation and evolution, represent a considerable challenge for pig health and production. Consequently, although only subtypes of H1N1, H1N2, and H3N2 are endemic in swine around the world, extensive diversity can be found in the hemagglutinin (HA) and neuraminidase (NA) genes, as well as the remaining six genes. We review the complicated global epidemiology of IAV in swine and the inextricably entangled implications for public health and influenza pandemic planning.

Influenza viruses (IV) are one of the major threats to human and animal health worldwide due to the variety of species they affect. Pigs play an important role in IV ecology as the "mixing vessel," since they can be infected by swine, avian and human IV, allowing the appearance of new subtypes. Human viruses originated in swine are known as IV of swine origin or swine influenza virus (SwIV) variants. In this study, we identified knowledge tendencies of SwIV and assessed potential bias in the literature caused by these variants. We identified the most mentioned SwIV variants and manually reviewed the literature to determine the number of publications applying the whole influenza nomenclature, a partial nomenclature, only the subtype or mixed terminology, along with the proportion of articles in which the GenBank ID number was available. We observed that the 2009 H1N1 human pandemic created an important bias in SwIV research driven by an increase in human publications on the IV of swine origin. H1N1 is the most studied subtype for swine and humans, followed by H3N2. We found differences between the nomenclatures applied, where partial classifications were slightly more common. Finally, from all the publications, only 25% stated the GenBank ID of the sequence studied. This review represents the most complete exploration of trends in SwIV knowledge to date and will serve as a guidance for future search strategies in SwIV research.

2010

Summary Swine origin influenza was first recognized in the border area of Mexico and United States in April 2009 and during a short span of two month become the first pandemic. It is a subtype of influenza A i.e. H1N1 strain, which has undergone triple reassortment and contain genes from the avian, swine and human. Influenza virus is a member of the genus orthomyxovirus, family orthomyxoviridae. Influenza virus expresses two envelope glycoproteins: Hemagglutinin (H) and Neuraminidase (NA). Hemagglutinin is known to mediate of virus to the target cells via sialic acid residue in glycoconjugates.which plays a key role in viral infection. Neuraminidase is a critical protein of influenza virus.it helps the virus to spread around the body. Antiviral neuraminidase inhibitor attacks the influenza virus and prevents it from spread inside the body such as Oseltamivir and Zanamivir. Admantanes are resistant due to S31N mutation toward to inhibit the flu. The rise in oseltamivir-resistant infl...

2010

The emergence of pandemic H1N1/2009 influenza demonstrated that pandemic viruses could be generated in swine. Subsequent re-introduction of H1N1/2009 to swine has occurred in multiple countries. Through systematic surveillance of influenza viruses in swine from a Hong Kong abattoir, we characterize a reassortant progeny of H1N1/2009 with swine viruses. Continued reassortment of H1N1/2009 with swine influenza viruses could produce variants with transmissibility and altered virulence for humans. Global systematic surveillance of influenza viruses in swine is warranted.

Pharmacologyonline

Swine origin influenza was first recognized in the border area of Mexico and United States in April 2009 and during a short span of two month become the first pandemic. It is a subtype of influenza A i.e. H1N1 strain, which has undergone triple reassortment and contain genes from the avian, swine and human. Influenza virus is a member of the genus orthomyxovirus, family orthomyxoviridae. Influenza virus expresses two envelope glycoproteins: Hemagglutinin (H) and Neuraminidase (NA). Hemagglutinin is known to mediate of virus to the target cells via sialic acid residue in glycoconjugates.which plays a key role in viral infection. Neuraminidase is a critical protein of influenza virus.it helps the virus to spread around the body. Antiviral neuraminidase inhibitor attacks the influenza virus and prevents it from spread inside the body such as Oseltamivir and Zanamivir. Admantanes are resistant due to S31N mutation toward to inhibit the flu. The rise in oseltamivir-resistant influenza A ...

Indian journal of forensic and community medicine, 2020

Swine flu, also called Hog or Pig Flu, is a contamination because of someone of the several forms of Swine Influenza Virus (SIV). It is common place through pig populace worldwide. Until now only folks were inside the direct contact with pigs were found to get swine flu. But, H1N1 virus is a brand new swine flu virus and it includes the genetic material of swine, hen and human influenza virus. H1N1 influenza or swine flu is a contagious disease this is as a result of the influenza virus. Infection with the H1N1 influenza virus can bring about intense illness and lifestyles threatening complications. Symptoms of H1N1 flu are similar to the ones of the common place flu and scientists are actively reading the scenario to better recognize its variety of signs and how it is spread. The intensity of this disorder may be lowered with the aid of diagnosing and taking proper treatments. Keywords: Swine flu, H1N1 influenza, Lifestyles-threatening, Common flu, Diagnosis, Management.

Future Microbiology, 2009

The Canadian Veterinary Journal La Revue Veterinaire Canadienne, 2010

In the spring of 2009, a new human influenza A H1N1 virus emerged in Mexico and the United States. The strain was referred to as “swine flu” as it has strong similarities with current circulating swine influenza viruses, although the first outbreak on a swine farm was recorded more than 2 mo following the first human reports. This new strain, designated as pandemic (H1N1) 2009, has shown the ability to spread amongst the human population and can be found on all continents. The way influenza viruses and specifically this influenza A pandemic (H1N1) 2009 virus evolve is described in this manuscript.