Pertussis Within the Realm of Public Health

PERTUSSIS 2

Jessie McCarty

Concordia University

Abstract

This paper explores the infectious disease of Pertussis. Pertussis, caused by the bacterial infection Bordetella pertussis, is a preventable disease within a community when the public is properly immunized. However, the number of people infected with pertussis on a yearly basis is continuing to rise (Carmon & Spratling, 2010). This paper provides an in-depth understanding of pertussis and explores the factors behind pertussis, with an emphasis on the disease within the realm of public health. Also, using research, this paper will further analyze why this preventable disease continues to affect people of all ages throughout the United States.

Pertussis Within the Realm of Public Health

Pertussis, also known to the general public as whopping cough, is an infection caused by bacteria. This bacterial infection is caused by Bordetella pertussis and leads to a harsh cough with multiple possible complications. Bordetella pertussis can be highly contagious, especially in children, and in some cases, infection from pertussis can be fatal (Hockenberry, 2003). Pertussis can be prevented, and the number of cases drastically reduced, by immunizing communities. Therefore, pertussis is a disease of great significance to public health departments throughout the United States. In order to control and prevent pertussis epidemics, public health departments must have an in-depth understanding of pertussis and the multiple factors influencing the spread, treatment, and prevention of pertussis.

Epidemiology

Bordetella pertussis can, at times, be a fatal disease. Therefore, understanding who is at risk for pertussis is extremely important for health care workers and the public health community. By studying the epidemiology behind pertussis, the public health community is better able to understand who is at risk for pertussis and how the disease is distributed across the population.

Cases of pertussis are usually found in children, typically at the age of four and under (Hockenberry,2003). Pertussis is usually reported in those children who have not received the immunization for Bordetella pertussis. Although cases of pertussis are usually talked about in reference to young children, pertussis can affect adolescents and adults also. The infection rates in adolescents and adults are believed to be correlated to eventually no longer having immunity from vaccinations given in childhood (SuMi, HyunSoo, OkKyung, Moon-Hyun,& WhaSook, 2010). Also, adolescents and adults with pertussis typically have more mild symptoms and the bacterial infection is not as severe (Crose, Cruz, & Tornabene, 2012).

Since pertussis is typically found in young children who have not been immunized, it is important to understand at what age immunization should take place. Pertussis involves a total of three immunizations by age six months, typically given as a mixture with the tetanus and diphtheria immunizations (Carmon & Spratling, 2010). However, according to statistics, in 2009 only 70.3% of children at seven months of age had gotten the set of three immunizations (Carmon & Spratling, 2010). The children, who are not immunized at all or who have not gotten the full set of three immunizations, are at the greatest risk to get pertussis. Statistics show Caucasian infants are most likely to get the immunizations and therefore “a disparity among races” (Carmon & Spratling, 2010, p. 239) is present when it comes to infants getting immunizations for pertussis. Not only are non-immunized children under the age of four most likely to get pertussis, but infants in particular are at a high risk for the disease. Infants are at greater risk to get pertussis due to their underdeveloped immune systems. Pertussis is more severe, and more deadly, in the infant populations (Hockenberry, 2003). Also, children in general with poor immune systems are at a higher risk for pertussis.

Once the health community understands who is at the highest risk for pertussis, it is then important to understand how the disease is distributed among the population. Epidemiologists have studied pertussis and how the spread of pertussis happens. Bordetella pertussis is diagnosed in patients typically by the description of the patient having a cough which sounds like a “whoop” noise. This cough produces respiratory secretions. Hockenberry (2003) explained transmission occurring person to person is from “direct contact or droplet spread from infected person; indirect contact with freshly contaminated articles” (p. 656). Therefore, pertussis is spread in a similar way as multiple other respiratory infections. As the infected person coughs into the air, a person standing in close proximity can breathe in this air and be exposed to the bacteria. Also, if the infected person coughs onto his or her hands and then touches an object, this object then can carry the bacteria. The next person to touch this object can then be exposed to the bacteria in the respiratory secretions and is now at risk to becoming infected by pertussis. By minimizing exposure to the infected person, the risk of transmission is lowered.

Those people with exposure to pertussis, particular those who have not been immunized, are at highest risk to pertussis. However, even with immunizations, pertussis cases have continued to increase since the 1980s (Carmon & Spratling, 2010). Pertussis is present throughout the United States, and according to Centers for Disease Control ( [CDC], 2012) “with periodic epidemics every 3 to 5 years and frequent outbreaks”. At the time this paper was written, the CDC was reporting Wisconsin as the state which reported the most known cases of pertussis with Washington and Montana also reporting high cases of pertussis. Local public health departments and the CDC both are responsible to monitor cases of pertussis. With close monitoring of pertussis, epidemiologists are able to constantly monitor where the disease is most localized and where it tends to spread.

Biomedical Basis

In order to truly understand the epidemiology behind pertussis, one must have an understanding of the biomedical basis behind pertussis. One way to understand the biological and molecular characteristics of pertussis is by explaining pertussis using the understanding of the chain of infection. The chain of infection consists of six different aspects: pathogen, reservoir, place of exit, method of transmission, port of entry, and susceptible host (Schneider, 2011). Pertussis is an “acute bacterial infection caused by Bordetella pertussis” (Hawkins, 2004, p.26). Pertussis starts with the Bordetella pertussis bacteria as a pathogen which then goes on to infect a human and can become highly contagious and become an epidemic. Understanding the biological and molecular characteristics of pertussis helps the scientific community and public health departments better treat and prevent pertussis.

Bordetella pertussis is a gram-negative bacteria (CDC, 2012). This gram negative bacteria produces many biologically and molecular responses. The presence of Bordetella pertussis “produces multiple antigenic and biologically active products including pertussis toxin, filamentous hemagglutinin (FHA), agglutinogens, adenylate cyclase, pertactin, and tracheal cytotoxin” (CDC, 2012). These responses to the gram negative Bordetella pertussis presence then cause the signs and symptoms that present in the reservoir infected with Bordetella pertussis.

The typical reservoir for Bordetella pertussis, as aforementioned, is a young child typically under the age of five (McCance & Huether, 2006). This pathogen, Bordetella pertussis, is typically a bacterium that affects young children, specifically those who have not been immunized to pertussis (Hockenberry, 2003). However, it is important to once again note Bordetella pertussis can affect adolescents and adults.

After affecting the chosen reservoir, the pathogen finds its place of exit to go get transmitted elsewhere. As mentioned earlier, pertussis is often transmitted via droplet transmission or contact transmission (Hockenberry, 2003). Often, the pathogen is transmitted via a cough. The Bordetella pertussis pathogen exits the infected person’s mouth by a cough and then is spread directly through the air into another person’s airway. However, the pathogen can exit via a cough onto an object which then transmits the bacteria via contact.

Once Bordetella pertussis is transmitted, it is able to enter the body of a new host by droplet or contact transmission. The port of entry is typically the mouth. The droplets of the pathogen can be inhaled by a new host via a cough. Also, not washing hands after touching infected objects can also provide a way for contact transmission if people touch their faces with contaminated hands. A susceptible host is often people around the infected person. However, those most susceptible are young children, those who are not vaccinated, and those with direct exposure to others with Bordetella pertussis, such as family members.

Once the chain of infection of Bordetella pertussis is understood, it is important to focus further on the infection process Bordetella pertussis causes inside one’s body. The “incubation period for pertussis is most commonly seven to ten days, with a range of four to twenty-one days” (Carmon & Spratling, 2010, p.239). The Bordetella pertussis pathogen attaches “to the cilia of the respiratory epithelial cells, produce toxins that paralyze the cilia, and cause inflammation of the respiratory tract, which interferes with the clearing of pulmonary secretions” (CDC, 2012). This process of infection causes the signs and symptoms related to pertussis. These signs and symptoms include “severe coughing, whooping, and post-tussive vomiting which can last for many weeks” (Carmon & Spratling, 2010, p.239).

Pertussis infections can typically be separated into three stages: catarrhal, paroxysmal, and convalescent stages (Carmon & Spratling, 2010). The first stage, catarrhal stage, can mimic the common cold with symptoms such as sneezing, low grade fever, rhinorrhea, and a minor cough. However, next in the paroxysmal stage, coughing worsens and a whooping noise is often heard after a cough (Rittle, 2010). Also, it is important to note other symptoms, such as fever, cyanosis, and post-tussive emesis, may also be present during this stage, especially with young infants (Carmon & Spratling, 2010). Carmon & Spratling (2010) noted this stage “can last up to ten weeks, with a typical duration of one to six weeks” (p.239). After the completion of the second stage, the third and final stage, convalescent stage then starts. This stage is typically two to three weeks but may last for months. Often, this stage consists of less severe symptoms and the body recuperating.

Knowledge behind the molecular and biological process of Bordetella pertussis is important to understand how the pathogen infects a person and how the chain of infection occurs. An in-depth understanding of these processes provides the public health and scientific community with a better ability to not only treat those with Bordetella pertussis, but to prevent and educate the public regarding the disease.

Social and Behavioral Factors

Pertussis is a preventable disease with a known vaccine. However, pertussis still continues to affect multiple children, adolescents, and adults every year. Carmon & Spratling (2010) even stated “the number of reported cases of pertussis has steadily increased, particularly among the infant and adolescent age groups” (p.239). Unlike many communicable diseases, pertussis rates have not steadily declined with the introduction of a vaccine. However, scientific research has shown the vaccine does work in preventing pertussis if given correctly and boosters are given. Cherry (2005) explained “data presently exists that suggest that vaccine-induced immunity is actually better than induced by pertussis infection” (p.1426). Therefore, vaccines do provide immunity to those who receive the vaccine. However, with the rise of pertussis rates continuing, it is clear there must be social and behavioral factors related to pertussis.

Health Belief Model

The health belief model of health behavior helps “determine whether a person is likely to change behavior when faced with a health threat” (Schneider, 2011, p.231). A person must feel there is a real chance to get a certain disease and that they are actually susceptible to the disease (Schneider, 2011). They also have “perceived barriers to taking action to reduce the risk and the perceived effectiveness of taking an action to prevent or minimize the problem (Schneider, 2011, p. 231). The concepts of the health belief model can be applied to pertussis to understand some social and behavioral factors related to pertussis

Those in public health must first make certain the public knows pertussis is a serious disease which can have severe complications. Often, the public does not understand what pertussis is and who is vulnerable to pertussis. Also, people assume they have had a vaccination once as a child and are protected. Therefore, people do not feel vulnerable to the disease. Rittle (2010) stated “Many adults think that pertussis is a thing of the past” (p.283). By educating the public about the seriousness of pertussis and the continuation of the spread of pertussis, the public will understand they are vulnerable to the disease and there is a threat. In the state of Wisconsin, the public health department has commercials on television during pertussis outbreaks. These commercials explain the possible deadly consequences of becoming infected with pertussis. These commercials on television use the health belief model of health behavior to remind the public they are not only vulnerable to the disease, but there is also a current outbreak of pertussis in the state which is a real threat to the public.

Once the public realizes they are vulnerable to pertussis and pertussis is a current threat to their health, public health departments must analyze why people may continue to not get immunized for pertussis. Often, the cost of immunizations is an obstacle for the public. Also, immunizations can be inconvenient and the schedule of immunizations and boosters can be confusing. The public health departments must recognize these obstacles and find ways to work around these obstacles to ensure the public gets immunized for pertussis. Also, the public health department must prove to the public that by getting immunized, the public is safer and less likely to get pertussis. Education must be provided to the public on the effectiveness of the pertussis vaccine. By showing the vaccine works, and by eliminating obstacles to getting the vaccine, the public will be more likely to get immunized.

Ecological Model

The health belief model helps the public health department understand the psychological aspects behind health behaviors related to pertussis. The ecological model “describes five levels of influence that determine health related behaviors” (Schneider, 2011, p. 233). The first level deals with intrapersonal factors. This level deals with solely the individual. These factors consider what a person thinks and knows about pertussis, his own feelings towards immunizations, his own attitude towards keeping up with immunizations, and the level of importance he places on his own health. Public health departments must analyze these intrapersonal factors before devising interventions to change behaviors regarding pertussis.