Indian Journal of Allergy, Asthma and Immunology

: 2017  |  Volume : 31  |  Issue : 2  |  Page : 37-

Swine flu: Brief overview

Saurabh Srivastava1, SN Gaur2,  
1 Department of Medicine, School of Medical Sciences and Research, Sharda University, Greater Noida, Uttar Pradesh, India
2 Department of Respiratory Medicine, School of Medical Sciences and Research, Sharda University, Greater Noida, Uttar Pradesh, India

Correspondence Address:
S N Gaur
Department of Respiratory Medicine, School of Medical Sciences and Research, Sharda University, Greater Noida, Uttar Pradesh

How to cite this article:
Srivastava S, Gaur S N. Swine flu: Brief overview.Indian J Allergy Asthma Immunol 2017;31:37-37

How to cite this URL:
Srivastava S, Gaur S N. Swine flu: Brief overview. Indian J Allergy Asthma Immunol [serial online] 2017 [cited 2023 Jan 27 ];31:37-37
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Full Text

Swine flu is a respiratory disease caused by influenza virus that infects the respiratory tract of pigs; the virus can be transmitted to humans. Swine flu strain, first seen in Mexico in 2009 as pandemic, was termed novel H1N1 flu since it was mainly found infecting people and exhibits two main surface antigens, H1 (hemagglutinin type 1) and N1 (neuraminidase type 1). The virus is formed by antigenic shift leading to the formation of new strain. This new strain is a hybrid virus, with its major surface hemagglutinin antigen sequences derived from swine, human, and avian flu sources. The eight RNA strands from the novel H1N1 flu have one strand derived from human flu strains, two from avian (bird) strains, and five from swine strains. Swine influenza is transmitted from person to person by inhalation of droplets containing virus from people by sneezing or coughing; it is not transmitted by eating cooked pork products.

Pandemic is centered primarily on young, healthy, adolescent populations. This segment of the population is typically highly mobile and exposed to crowded environments (schools, social gatherings, and traveling) and is infrequently immunized with annual influenza vaccines.

Symptoms of this flu are high fever, cough, fatigue, headaches, and mucous secretions. It is terrifying that the initial symptoms are so similar to regular flu that many might just ignore them. Fatality usually occurs due to the late or noneffective treatment of acute pneumonia.

The incubation period is about 1 to 4 days, with the average being 2 days; in some people, the incubation period may be as long. The contagious period for swine influenza in adults usually begins 1 day before symptoms develop in an adult and it lasts about 5–7 days after the person becomes sick. People with weakened immune systems, children, and elderly may be contagious for a longer period of time. Uncomplicated swine flu infections typically begin to resolve after 3–7 days. Some patients develop severe respiratory symptoms, such as shortness of breath and need respiratory support. Patients can have pneumonia and can also develop seizures. Infection can sometimes be fatal if appropriate treatment is not given. Advanced and untreated cases can lead to systemic involvement of liver and kidney and rarely can lead to acute respiratory distress syndrome.

Simple precautions such as washing hands, wearing face masks, sneezing under a mask if having flu-like symptoms, and avoiding traveling to crowded areas can help in prevention from the disease. Use of N95 mask is recommended to high-risk groups such as medical fraternity, nurses, and caregivers.

Antiviral agents reported to prevent or reduce the effects of swine flu are oseltamivir and zanamivir. Both are also used to prevent or reduce influenza A and B symptoms. The best way to prevent novel H1N1 swine flu is vaccination. The Centers for Disease Control and Prevention has recommended that everyone, 6 months and older, should get flu vaccination to prevent or reduce the chance of getting the flu.