Tuesday, December 10, 2019

Resurgence Of Vaccine-Preventable Disease - Myassignmenthelp.Com

Question: Discuss about the Resurgence Of Vaccine-Preventable Disease. Answer: Among the different infectious diseases considered as global health concerns, whooping cough is a significant one due to the high incidence rate in spite of strong vaccination programs. The present essay describes the symptoms and mechanism of infection of B. pertussis and discusses the method of identifying the causative organisms. The next section of the essay highlights the reason behind the high incidence of a whooping cough despite childhood vaccination programmes and why the disease is a global public health concern. The paper also brings into limelight the role of vaccination in disease prevention and the present recommendations for B. pertussis management. Pertussis, commonly known as whooping cough, is a highly contagious disease and the causative agent is the bacteria Bordetella pertussis. This disease has become a major global public health concern. At the initial stage, patients suffer from a runny nose, mild cough and fever. Thereafter, the patient suffers weeks of severe coughing fits. The name of the disease is so given since a high-pitched whoop sound is produced as the patient breaths in. The coughing usually lasts for 10 weeks, and this is why the disease is also known as 100-day cough (Hegerle and Guiso 2013). Pertussis is an airborne disease that spreads through sneezes and coughs of the infected person. The bacterial infection is primarily caused by the pertussis toxin; however, invasion of alveolar macrophages and tissues is also a part of the infection mechanism. The bacteria attaches to the hosts' respiratory epithelial cells cili, where is is known to produce toxins responsible for paralysing the cells. As a result, th e respiratory tract suffers inflammation, hence causing interference with the mucociliary escalator which is responsible for clearance of pulmonary secretions (Pawloski et al. 2014). Figure: Immunosuppresion by B. pertussis (Carbonetti 2007) An overall impression of the physician is much needed for initially making the diagnosis of B. pertussis as single factors are not much useful. The methods that are commonly used for laboratory diagnosis include the culture of swabs of nasopharyngeal on a nutrient medium, Polymerase Chain Reaction (PCR), serological methods and direct fluorescent antibody (DFA) method. The bacteria is to be recovered from the patient only during the initial three weeks of illness as the DFA method, and culturing method is useless after this time. PCR also has limited usefulness after this time. Serology is useful for patients who are already infected for many weeks for determining whether there is the presence of antibody against pertussis toxin in the blood at a high level (Melvin et al., 2014). The role of vaccination against pertussis has been well studied in the past as the primary method of prevention. The World Health Organisation (WHO) recommends the use of pertussis vaccine as it had saved almost half a million lives in the year 2002. There are two forms of pertussis vaccines, whole cell vaccines and acellular vaccines, of which the former one is not into use at present. The acellular pertussis vaccine is 85% effective, and this is more profound for strains that are more severe. The vaccine for a whooping cough is included as a component in the combination shots including diphtheria and tetanus (Tdap, DPT, DTap). The DTP vaccine had been highly reactive, carrying a high risk of allergic reactions and inflammation of the brain (Brennan 2017). Figure: Pertussis global annual reported cases (who.int 2017) In spite of the widespread vaccination, pertussis has become a persistent disease among the vaccinated populations, and it is now one of the common vaccine-preventable diseases in countries across the globe. Worldwide, there are approximately 24.1 million cases of pertussis and the number of deaths per year is around 160,700. WHO estimated that in 2008, almost16 million cases of pertussis occurred when studies on a worldwide basis. The cases reported in developing countries accounted for 95% of the total number of cases. Further, 195,000 children suffered mortality due to the disease (who.int 2011). As opined by Edwards and Decker (2018) the resurgence of pertussis in the 21st century can be attributed to the amalgamation of bacterial mutations and waning immunity responsible for eluding vaccines. It has been found that immunisation through vaccination is not capable of conferring lifelong immunity. A study conducted in the year 2011 by the Centre for Disease Control and Prevention (CDC) had found that an individual can be protected from the disease for maximum six years after getting vaccine doses. This can cover only the stages of childhood, and it is to be remembered that the childhood is the time of greatest risk of exposure and death from pertussis. A rich pool of resources has found that infection is effective in inducing incomplete natural immunity waning over time. CDC and WHO have pointed out that vaccination is effective in the prevention process but not effective in restricting transmission and infection. This implies that people getting vaccinated have chances of ser ving as asymptomatic reservoirs of pertussis infection (Centers for Disease Control and Prevention 2012). Simplifying the matter, Warfel, Zimmerman and Merkel (2014) stated that the global resurgence of pertussis cases is due to the failure of acellular pertussis vaccines. In dissimilarity to whole cell pertussis vaccines used previously, acellular vaccines demonstrate less safety and efficiency. It has also been alleged that the whole cell vaccines could block the spread of infection, unlike the acellular vaccines. However, there is much debate regarding the clarification of this assumption as evidence of the ineffectiveness of whole-cell vaccines are also present. In the present times, a key public relations crisis is caused by distrust of public in vaccine safety. The resurgence of the disease in the present era marked by the use of acellular vaccine is moving into a global public health crisis. At present, deaths among infants due to this infection is at a 70-year high though vaccination is also more into use. Apart from the contributing factors such as waning immunity, vaccine refus al is a key cause of this resurgence. Further, cocooning, the process of giving Tdap to all house contacts of a newborn for prevention of a whooping cough presupposes that vaccine for pertussis prevents infections that are asymptomatic (Cherry 2012). As a recommendation, Klein et al. (2017) suggested that since it is necessary to arrest the growing concern of pertussis, there is a need of state and country legislations that can reform pertussis vaccination process immediately. Educating the leaders in the communities is also necessary. National vaccine policy recommendations are to be put forward so that laws are made at the state level. In addition, governments must focus on funding research that can throw light on novice approaches for pertussis vaccination. In conclusion, the prevalence of pertussis incidence is on the rise, and both biological and social factors are to be blamed for this. The disease is at present a major public health concern, the drawing attention of health authorities. Advanced research aligned with policy reforms can hopefully help in arresting the issue in future. References Brennan, M.J., 2017. A New Whooping Cough Vaccine That May Prevent Colonization and Transmission.Vaccines,5(4), p.43. Carbonetti, N.H., 2007. Immunomodulation in the pathogenesis of Bordetella pertussis infection and disease.Current opinion in pharmacology,7(3), pp.272-278. Centers for Disease Control and Prevention (CDC, 2012. Pertussis epidemic--Washington, 2012.MMWR. Morbidity and mortality weekly report,61(28), p.517. Cherry, J.D., 2012. Epidemic pertussis in 2012the resurgence of a vaccine-preventable disease.New England Journal of Medicine,367(9), pp.785-787. Edwards, K.M. and Decker, M.D., 2018. Pertussis vaccines. InPlotkin's Vaccines (Seventh Edition)(pp. 711-761). Hegerle, N. and Guiso, N., 2013. Epidemiology of whooping cough typing of Bordetella pertussis.Future Microbiology,8(11), pp.1391-1403. Klein, N.P., Bartlett, J., Fireman, B., Aukes, L., Buck, P.O., Krishnarajah, G. and Baxter, R., 2017. Waning protection following 5 doses of a 3-component diphtheria, tetanus, and acellular pertussis vaccine.Vaccine,35(26), pp.3395-3400. Melvin, J.A., Scheller, E.V., Miller, J.F. and Cotter, P.A., 2014. Bordetella pertussis pathogenesis: current and future challenges.Nature Reviews Microbiology,12(4), pp.274-288. Pawloski, L.C., Queenan, A.M., Cassiday, P.K., Lynch, A.S., Harrison, M.J., Shang, W., Williams, M.M., Bowden, K.E., Burgos-Rivera, B., Qin, X. and Messonnier, N., 2014. Prevalence and molecular characterization of pertactin-deficient Bordetella pertussis in the United States.Clinical and Vaccine Immunology,21(2), pp.119-125. Warfel, J.M., Zimmerman, L.I. and Merkel, T.J., 2014. Acellular pertussis vaccines protect against disease but fail to prevent infection and transmission in a nonhuman primate model.Proceedings of the National Academy of Sciences,111(2), pp.787-792. Who.int. (2011).WHO | Pertussis. [online] Available at: https://www.who.int/immunization/topics/pertussis/en/ [Accessed 10 Jan. 2018]. World Health Organization. (2017).Pertussis. [online] Available at: https://www.who.int/immunization/monitoring_surveillance/burden/vpd/surveillance_type/passive/pertussis/en/ [Accessed 10 Jan. 2018].

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