A Comprehensive Report On The H1n1 Influenza Virus

Table of Contents


An opening statement

Causative Agent

The problem’s magnitude

Predisposing Factors

People at higher risk for infection include

Moving information from one place to another

Patient’s symptoms

Prevention and Control


In conclusion



The H1N1 Swine influenza virus is a strain of influenza A that differs in two surface glycoproteins: hemagglutinin (or neuraminidase) and hemagglutinin. It is thought that the novel virus spreads through respiratory particles. Coughing and sneezing are some of the ways it can be transmitted. After the infection, the symptoms can vary from mild upper airway illness to serious complications including pneumonia resulting into respiratory failure or acute respiratory distress syndrome. The novel H1N1 strain was first detected in Mexico in 2009. In June 2009, WHO declared that the 2009 pandemic had begun. This pandemic had a tremendous impact. The pandemic affected not only the health of the community but also other aspects such as economics and social. There are many measures to control the H1N1 virus, both non-pharmacologically and pharmacologically. The need for more extensive research on this novel viral strain has prompted this paper to highlight the scope of the issue, the transmission potential, and predisposing variables. It also discusses the many aspects of clinical presentations, prevention, as well as control. IntroductionH1N1 Swine Flu is an infection which is widespread in pigs all over the world. This is why it is called swine fever. H1N1 is a respiratory disease that can affect pigs. Swine flu can sometimes be transmitted to people by pigs. Swine influenza viruses can potentially cause human infections if the virus changes its antigenic characteristics by reassortment.Influenza A pandemics such as those which occurred in 1918 and 2009 can occur when transmission from person to person becomes successful. A devastating pandemic of influenza caused by H1N1 flu virus, or Spanish flu, occurred in 1918. It was the deadliest pandemic ever recorded. In 2009, a swine/human influenza outbreak (H1N1) which spreads from pigs into humans started in Mexico. It spread rapidly throughout the world. This new “pandemic”, though not clear when it occurred, was caused by a three-fold influenza A strain carrying the swine genome, Eurasian Avian, and Human strains. The causative agentThe H1N1 virus is an orthomyxovirus. It develops virions of 80-120 nm diameter.

* The envelope proteins hemagglutinin(HA) and neuraminidase(NA)

* Viral RNA polymerases, including PB2, PB1, PB1F2, PB1-F2, PB1-F2, and PB

* Matrix protein M1 andM2

* Nonstructural NS1-NS2 proteins (NEP), essential for efficient viral replication.

H1N1strain is different from other influenza A (H1N1, H1N2) strains because of the surface glycoproteins HA and NA. Hemagglutinin binds the virus and red blood cell together. Neuraminidase assists in the transfer of viral particles between infected cellular. The problemH1N1 first appeared in Mexico, on 18 March 2009. In just a few weeks, 30 countries were affected by the outbreak. By June 11, WHO had declared that the 2009 flu pandemic was underway by raising the alert level to phase 6, as 74 different countries reported nearly 30,000 H1N1 infections. By July, the virus had spread to more than 122 nations with 134,000 lab-confirmed infections and 800 fatalities. The global nature of travel and trade has allowed swine-flu to be spread in the same way as other pandemics took six months. By December of 2009, more 208 countries reported swine fever cases. By March 2010, more than 17700 deaths were reported in lab-confirmed cases. In the United States as of mid February 2010, 59 million illnesses were reported, 265 000 hospitalizations occurred, and there were 12 000 deaths. Importantly, the estimate of mortality was likely underestimated due to its reliance on statistics attributed to excess mortality for all causes and not laboratory-confirmed patients. According to Saudi Arabia’s Ministry of Health on 30 December 2009, there were 15.850 laboratory confirmed cases, and 124 deaths. The pandemic was not only a medical disaster, but also a social disruption. Airlines reported losses of tens or even hundreds of millions. Mexico’s international air traffic decreased by 40% after travel restrictions were implemented in some countries to try to slow or stop the spread of the disease. The closing of US schools for four weeks on average cost 47 billion dollars (0.3% GDP), and resulted in a 19% reduction in key healthcare staff. Predisposing variablesOverall, those who are more likely to be infected by this virus are:

Children under 5 years of age.

Children under the age of 19 and adults older than 65 years old who have been on long-term Aspirin therapy.

People who have a compromised immune system due to diseases like AIDS.

Females currently in gestation.

People who suffer from chronic diseases, including diabetes, heart diseases, neuromuscular disease and asthma.

TransmissionThe most common way to transmit the virus is by droplets from coughing, sneezing or direct or indirect contact of respiratory secretions. Handling surfaces contaminated with virus (fomites), inhaling aerosols of bacteria into the mouth or nose. Fomites (e.g. Toys for children can spread disease by contact with them. Infectious airborne aerosols contain large droplets as well as droplet nuclei. The diameter of large respiratory droplets is >5-10?m. They are responsible for short-range transmission. The droplet nuclei have a diameter 5 mm and are responsible for the long-distance (airborne) transmission. Rapid spread has been observed in the population and especially in places like schools where there are many people. Clinical PresentationThe symptoms are similar to seasonal influenza (H1N1): fever, sore throats, malaise, headaches, myalgias, arthralgias, fatigue, and cough. Many patients, particularly in the pediatric group, had diarrhea and vomiting. This is not something that happens with seasonal flu. The data suggests that the H1N1 infection has a broad clinical spectrum. It can range from mild upper-respiratory tract symptoms to serious complications including respiratory failure, acute respiration distress syndrome (ARDS), and multi-organ dysfunction. The symptoms of diarrhea, which are reported by 20%-50% percent of patients do not need to be hospitalized. In certain countries, viral pneumonia is the main cause of hospitalization. Microbiological evidence for secondary bacterial and fungal infections has been detected in fatal events…In the USA, more than 70% of hospitalized patients had conditions that put them at a high risk of complications. According to surveillance data, individuals with chronic diseases and pregnant women are more likely to have severe or complicated flu illness. With this pandemic virus, an additional factor of risk has emerged: obesity. Incubation periods for the pandemic influenza virus are also similar to seasonal influenza. They range between 1 and 7 days. Ill children may shed the virus up to 7 day after the illness began. However, some groups of children such as immunocompromised or young infants can have longer viral transmission. The infectious period of influenza for prophylaxis is 1 day prior to fever onset and 24 hours following fever end. In order to control and limit the spread of influenza, developing countries use a variety of non-pharmacological and pharmacological interventions. Non-pharmacological actions include: personal cleanliness, washing of hands with soap, covering of the mouth and nasal passages while coughing or wheezing. Close contact quarantine and mandatory isolation. The health worker should collect the samples using biosafety equipment. Pharmacological measures include antiviral (oseltamivir & zanamivir) drugs. It is recommended that these be administered within 48 hour of symptom onset. This drug should also be given as a priority to those patients at high risk of serious illness. Health workers should receive antiviral prophylaxis for up to six weeks with oseltamivir or four weeks with zanamivir. Close contacts and patients who do not receive prophylaxis are also advised to start treatment early with an antiviral medication. Few countries offer the vaccine. It is a very effective way to reduce influenza-related morbidity and death. The A/California/07/2009/H1N1 strain is the basis for this vaccine. It comes in both live attenuated and an inactivated version. Single doses are sufficient for children older than 9 and adults 18-64. Children under 10 will need two doses, separated by 21 days. Live attenuated vaccines are only available to persons between the ages of 2 and 49 who are not pregnant and immunocompetent and do not have chronic diseases. It is contraindicated for children under 5 years old with asthma, those taking long-term aspirin and anyone in close contact immunosuppressed individuals. Inactivated vaccination is not recommended for those with severe egg allergies or other vaccine components. The H1N1 subtype is an influenza virus that causes upper and lower respiratory infections. As of 30 December 2009, there were 15850 laboratories in Saudi Arabia, with 124 fatalities. It spreads through the droplets from coughing and sneezing. It can cause gastrointestinal inflammation, as well as a fever, sore throat and headache. In addition to antiviral treatment, prevention measures include mouth, nose and hand coverings when sneezing and coughing. Live attenuated or inactivated vaccinations come in two different types. Cites

Kshatriya RM, Khara NV, Ganjiwale J, Lote SD, Patel SN, Paliwal RP. Lessons Learnt From The Indian H1N1 Epidemic: Predictors Of Outcome Based On Epidemiological And Clinical Profile. Journal of Family Medicine and Primary Care. 2018 Nov-Dec; 7(6):1506-1509.

Lopez, A., & Martinson, S. A. (2017). Respiratory System. Mediastinum. Pleurae. Pathologic Basis for Veterinary Diseases, 471-560.e1. doi:10.1016/b978-0-323-35775-3.00009-6

Keenliside A. Pandemic influenza A in Swine. Curr. Top. Microbiol. Immunol. 2013; 370:259-71.

Nogales A, Martinez-Sobrido L, Chiem K, Topham DJ, DeDiego ML. Functional Evolution Of The 2009 Pandemic Influenza A Virus NS1 And PA In Humans. J. Virol. October 2018; volume 92, issue 19

Baudon E, Chu DKW, Tung DD, Thi Nga P, Vu Mai Phuong H, Le Khanh – -Hang N, Thanh LT, Thuy NT, Khanh NC, Mai LQ, Khong NV, Cowling BJ, Peyre M, Peiris M. Swine influenza viruses in Northern Vietnam in 2013-2014. Emerg Microbes. In 2018, a study with a focus on the topic of [subject] was published in the journal [publication name], Volume 7, Issue 1, on July 2. Influenzavirus A. ICTVdB Virus Description – 00046001 Influenzavirus A.

Sullivan, S. J., Jacobson, R. M., Dowdle, W. R., & Poland, G. A. (2010). 2009 H1N1 Influenza. Mayo Clinic proceedings, 85(1): 64-76. doi:10.4065/mcp.2009.0588

Saunders-Hastings, P., & Krewski, D. (2016). Reviewing Pandemic Influenza History and Transmission Patterns. Pathogens, 5(4), 66. doi:10.3390/pathogens5040066

Bautista E. Chotpitayasunondh T. Gao Z. Harper SA. Shaw M. Uyeki T. Figshare; 2010 [cited 2020Apr4]… Available from: https://hdl.handle.net/2381/15212

AlMazroa, Memish, and AlWadey (2020) conducted research to … Pandemic Influenza A (H1N1): Description of the First Hundred Cases. Ann Saudi Med. 2010; 30(1):11-14. doi:10.4103/0256-4947.59366

Bajardi P, Poletto C, Ramasco J, Tizzoni M, Colizza V, Vespignani A. Human Mobility Networks and Travel Restrictions: Global Spread of the 2009 H1N1 Pandemic. PLoS ONE is a scientific journal. 2011;6(1):e16591

Rutkowski, Michael. The Economic and Social Effects of Closing School During a H1N1 Influenza Epidemic. University of Pittsburgh Master’s Dissertation [Internet]. D-scholarship.pitt.edu. [cited 21 Mar 2020].

Global Health Observatory Map Gallery on the Internet World Health Organization (WHO). World health organizer (WHO).

Jilani T, Jamil R, Siddiqui A. H1N1 Influenza (Swine Flu) [Internet]. Ncbi.nlm.nih.gov. 2020 [cited as 19 March 2020].

Mathematical model of pandemic H1N1 2009 The Weekly Epidemiological Record published an article in 2009 that discussed topics ranging from 341 to 348. Citation [March 20]

CDC. Outbreak of influenza A virus (H1N1) with swine origin in Mexico, March-April 2009. MMWR Morb Death Wkly Report. 2019; 58 (17):467-4470. Cite [2020 Mar 20].

Dalton CB, Cretikos MA, Durrheim DN, et al. Comparison of pandemic H1N1 influenza in adult patients hospitalized during the Protect phase of pandemic response. Med J Aust 2019. 192-356.cited. [2020 March 20].

Human infection by pandemic influenza A (H1N1) virus in hospitalized individuals. Wkly Epidemiol Rec 2018, 84-305.cited by [2020 Mar 20].

Lera E, T.Worner N, Sancosmed M, Fabregas A, Casquero A, Melendo S et al. Clinical and epidemiological features of influenza A (H1N1) patients treated in the emergency room at a pediatric hospital. The European Journal of Pediatrics publishes research concerning children’s health and development. 2011; 170(3):371-378.

RMIT Training (Australia) PTY LTD. The Aboriginal and Islander Health Worker Journal is a publication that highlights the health issues that are faced by Aboriginal and Islander people. Aboriginal and Islander Health Worker Journal.

Centers for Disease Control and Prevention. Update on influenza A (H1N1) 2009 monovalent vaccines [Internet]. MMWR. The Morbidity And Mortality Weekly Report U.S. National Library of Medicine. 2009 [cited on 2020Mar20].

Greenberg ME. Neuzil Nvan. Holshue. Guan. Affiliations. Clinical Research and Development. Response to a Monovalent 2009 Influenza A (H1N1) Vaccine: NEJM [Internet]. The New England Journal of Medicine is a medical journal that publishes research articles and reviews. 2009 [cited 2020Mar20].


  • kianstafford

    Kian Stafford is a 39 year old educational blogger and school teacher. He has been teaching for over 10 years and has worked in a variety of different positions. Kian has an extensive knowledge of education, both online and in-person, and has written extensively on education topics. He is also a member of several education organizations, and has been involved in many educational initiatives.



Kian Stafford is a 39 year old educational blogger and school teacher. He has been teaching for over 10 years and has worked in a variety of different positions. Kian has an extensive knowledge of education, both online and in-person, and has written extensively on education topics. He is also a member of several education organizations, and has been involved in many educational initiatives.