H1N1 Pandemic of 2009

H1N1 Pandemic of 2009

The H1N1 influenza pandemic of 2009 is one of the worst outbreaks reported in the world. The disease caught the world by surprise leading to massive loss of lives irrespective of the efforts by the Centers for Disease Control and Prevention (CDC). The H1N1 influenza outbreak is referred to as a pandemic because it spread through many countries and continents (CDC, 2010). The spread was rapid, and within a few weeks, after the first case was reported, multiple cases from various countries were observed. The outbreak of the virus in 2009 occurred against a backdrop of planning by the government at all levels including years of exercising response plans at local, community and international levels. The primary concern during the period was that of influenza A (H5N1) viruses thus the emergence of the H1N1 virus was a complete shock. This paper discusses the outbreak of the H1N1 virus, countries involved, the epidemiological perspective of the outbreak, risk factors for the outbreak, mode of transmission and the impact of the disease on the community.

H1N1 influenza virus was first detected in the United States in April 2009 and reports indicated a novel virus never previously identified in people or animals. Further analysis of the virus showed that the strains of the causal agents were related to those of North American Swine lineage and the Eurasian lineage of H1N1 influenza viruses (CDC, 2010). The report from CDC led to the declaration of the outbreak as ‘swine flu’ in 2009. In the United States, swine flu was first reported in California where a 10-year-old patient was diagnosed with the disease. Two patients, 130 miles away from the initial patient, were later diagnosed with the disease and reports from CDC indicated that the viruses were similar thus confirming the spread of the disease. Before the identification of the disease in California, Mexico was the first country to present reports of the suspected disease outbreak (CDC, 2010). In March and April 2009, students who had visited Mexico for a holiday vacation traveled back with the disease, and one week later the outbreak was detected. The first case in Canada was reported on April 6, 2009, and subsequent reports indicated 21 countries were affected by the outbreak. By May 6, 2009, the disease had spread in several states in the United States with 1487 laboratory reports confirming the presence of the virus in more than 43 states (CDC, 2010). The reports from various countries led to the declaration of the disease as a pandemic by the World Health Organization on June 11, 2009.

Epidemiological Determinants

The epidemiological determinants of the H1N1 virus are dependent on the immune system of the individuals and the environmental conditions during the outbreak (Jhung et al. 2009). The causative agent of the disease is Influenza A virus well known to attack individuals without prior immunity to the agent. Various host factors are associated with the acquisition of the infection. The disease occurs in all age groups where the population has no immunity to the virus. According to the CDC reports, even those individuals with some resistance to the disease are affected during outbreaks due to high infectivity rate of the virus (Jhung et al. 2009). The virulence of the disease is observed more in individuals with underlying diseases and conditions such as pregnancy, cardiac conditions, and renal diseases. During the 2009 pandemic, obese individuals were found to be more affected by the disease (Al-Muharrmi, 2010). However, there is no clear explanation for the attack of obese individuals with the virus.

H1N1 viruses are highly resilient in the environment with several environmental determinants increasing the spread and infectivity of the virus. Low humidity and low temperatures favor the aerosol transmission mode. It is observed that the two major outbreaks of the H1N1 virus occurred during the spring season (Al-Muharrmi, 2010). The seasonal outbreak of the virus is also observed in temperate climates explaining the environmental resiliency of the virus. Tropical climates are not favorable for the outbreak of influenza virus, but rainy seasons accelerate the spread of the H1N1 virus. The best environment for the H1N1 virus is a population without pre-existing immunity, and the pandemic spreads faster when the environmental conditions are abundant.

Route of Transmission

The major routes of transmission of the H1N1 virus are through droplets from sneezing or coughing from the affected individuals. Direct or indirect contact with the respiratory secretions of an individual infected with the virus transmits the disease to the individuals. Statistics from the 2009 H1N1 pandemic indicates that the transmission of the disease was accelerated by traveling (WHO, 2009). Transmission through food is not yet known, but it forms an indirect mechanism of contact with respiratory secretions.

Risk Factors

The risk factors for the H1N1 virus are associated with the immunity of individuals. According to the CDC immunocompromised individuals are at higher risk getting the disease. Children younger than five years and the adults of 65 years and above are at high risk of getting the disease (WHO, 2009). Individuals with underlying medical conditions such as asthma, chronic lung diseases such as COPD, blood disorders such as sickle cell anemia and those individuals with weakened immunity due to HIV/AIDS and Cancer are at high risk of getting the disease. During the 2009 outbreak of H1N1, traveling was the most prominent risk factor for the disease as it increased the chances of individuals contacting the virus.


How the Outbreak Can Affect a Community

An outbreak of H1N1 causes adverse effects in the community because of the disrupted community activities and systems. The economic impact of a pandemic is fatal to the community and the country at large since productivity is affected. Taking a look at the case fatality rate of the 2009 pandemic, several people lost their lives, and business was affected due to the loss (Jhung et al. 2009). The regular activities in the community will be compromised due to disease spread. The educational system is no exception when pandemics emerge because of school closure. Children and the elderly are more affected by the H1N1 virus because f their low immunity thus parents are forced to stay with the children as the disease is eradicated. The transport is mainly affected when pandemics arise due to restricted movements. As observed earlier, traveling formed one of the greatest risk factors for the spread of the H1N1 virus during the 2009 epidemic. The health sector in the community is likely to be faced with challenges during outbreaks because of the resources needed to eradicate the disease.

Reporting Protocol

The reporting protocol for the H1N1 outbreak in Harford County starts with notifying the health departments in the facility. An online form (The DHMH 1140) is available for filling of the required information during reporting of the incident (CDC, 2010). Telephone media is also used when cases are observed in institutions such as schools where the head teacher calls the Bel Air Branch of Harford County Health Department to give relevant information regarding the incident. The incident is then reported to the CDC by the state health department where appropriate action is taken. Investigations follow the reporting of the outbreak and number of cases is determined by the CDC.

Prevention Strategies

Health education is the first strategy used to prevent H1N1 outbreaks in the community. Personal protective measures such as shielding the mouth when coughing and hand washing help prevent disease transmission. Isolation and quarantine are used when mass casualties are observed during the outbreak (WHO, 2009). Operations such as schooling and traveling are stopped during the outbreak for effective control of the pandemic. Vaccination and chemoprophylaxis are now available for prevention of H1N1 virus. The outbreaks are likely to affect schools and the hospitals as many people will be infected. The local governments are involved in organizing the quarantine activities and the regulation of traveling during the outbreak.


Jhung, M. A., Swerdlow, D., Olsen, S. J., Jernigan, D., Biggerstaff, M., Kamimoto, L., … & Gindler, J. (2011). Epidemiology of 2009 pandemic influenza A (H1N1) in the United States. Clinical Infectious Diseases52(suppl_1), S13-S26.

Al-Muharrmi, Z. (2010). Understanding the influenza A H1N1 2009 pandemic. Sultan Qaboos University medical journal10(2), 187.

Centers for Disease Control and Prevention. (2010). The 2009 H1N1 pandemic: summary highlights, April 2009-April 2010. Official Online Article Published by the Centers for Disease Control4.

WHO. (2009). Infection prevention and control in health care for confirmed or suspected cases of pandemic (H1N1) and influenza-like illnesses. [Accessed December 2009]. Fromwww.who.int/csr/resources/publications/swineflu/swineinfinfcont/en/index.html.






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