Swine Flu: What should a Dentist Know
Influenza A viruses are found in many different animals, including ducks, chickens, pigs, whales and horses. According to Thacker and Janke pigs are unusual as they can be infected with influenza strains that usually infect three different species: pigs, birds and humans. This makes pigs a host where influenza viruses might exchange genes, producing new and dangerous strains. Because pigs are susceptible to avian, human and swine influenza viruses, they potentially may be infected with influenza viruses from different species at the same time. If this happens, it is possible for the genes of these viruses to mix and create a new virus. This type of major change in the influenza A viruses is known as antigenic shift. If this new virus causes illness in people and can be transmitted easily from person to person, an influenza pandemic can occur.
2009 H1N1 (referred to as “swine flu” early on) is a new influenza A virus subtype causing illness in people. This virus is spreading from person to person worldwide in much the same way that regular seasonal influenza viruses spread. On June 11, 2009, the World Health Organization (WHO) announced that the pandemic level of 2009 H1N1 flu had been raised to its highest level. According to the World Health Organization (WHO), a pandemic can start when three conditions have been met:
1-Emergence of a disease new to a population
Spread of 2009 H1N1 virus is thought to occur in the same way that seasonal flu spreads. Flu viruses are spread mainly from person to person through coughing or sneezing. Sometimes people may become infected by touching a surface or an object with flu viruses on it and then touching their mouth or nose. Studies have shown that influenza virus can survive on environmental surfaces and can infect a person for 2 to 8 hours after being deposited on that surface. 2009 H1N1 viruses are not spread by food. You cannot get infected with novel HIN1 virus from eating pork or pork products.
The symptoms of 2009 H1N1 flu include fever (It’s important to note that not everyone with flu will have fever), cough, sore throat, runny nose, muscle aches, headache, chills and fatigue. A significant number of people who have been infected with this virus also have reported diarrhea and vomiting. While most people who have been sick have recovered without needing medical treatment, hospitalization and death from infection with this virus have occurred.
One thing that appears to be different from seasonal influenza is that adults older than 64 years do not appear to be at increased risk of 2009 H1N1 related complications. Centers for Disease Control and Prevention’s (CDC) laboratory studies have shown that no children and very few adults younger than 60 years old have existing antibody to 2009 H1N1 flu virus; however, about one-third of adults older than 60 may have antibodies against this virus.
At this time, there are few cases and few deaths reported in people older than 64 years old, which is unusual when compared with seasonal flu as this age group is considered a high risk condition. However, pregnancy and other previously recognized high risk medical conditions from seasonal influenza appear to be associated with increased risk of complications from this 2009 H1N1. These underlying conditions include asthma, diabetes, suppressed immune systems, heart disease, kidney disease, neuromuscular disorders and pregnancy.
People infected with seasonal and 2009 H1N1 flu may be able to infect others from 1 day before the symptoms appear to 5-7 days after. This can be longer in some people, especially children and people with weakened immune systems.
CDC recommends the use of the antiviral drugs Oseltamivir or Zanamivir this season. Antiviral drugs are medicines that fight against the flu by keeping flu viruses from reproducing in the body; they may also prevent serious flu complications.
Influenza virus is destroyed by heat (75-100°C). In addition, several chemical germicides, including chlorine, hydrogen peroxide, detergents, iodine-based antiseptics and alcohols are effective against human influenza viruses if used in proper concentration for a sufficient length of time.
Arthur A. Dugoni Pacific School of Dentistry Infection Control Committee released the following protocol for managing dental patients with confirmed or suspected respiratory infection in accordance with the United States Centers for Disease Control and Prevention’s (CDC) guidelines:
Staff experiencing influenza-like-illness (ILI) (fever with either cough or sore throat, muscle aches) should not report to work. Staff who have difficulty breathing or shortness of breath, or are believed to be severely ill, should seek immediate medical attention.