Temporal Trends in Serotypes causing Pneumococcal Disease triggered by Respiratory Viruses
Viral infections such as 2009 H1N1 influenza virus and their seasonality can set off temporal trends in serotypes that cause Invasive Pneumococcal Diseases (Launes, 2014). Despite the availability of antibiotics and vaccines, pneumococcal diseases continue to have a high morbidity and mortality rate. Currently, pneumococcal diseases cause more than one million deaths yearly especially among the elderly and the children. Launes further explain that the 2009 influenza virus pandemic provided an opportunity to determine whether such respiratory viruses have an effect on the trends and distribution of serotypes that cause pneumococcal diseases.
Based on differences in capsular polysaccharide antigenic characteristics, over ninety serotypes have been isolated and classified into forty-six serogroups. The capsular polysaccharide determines the pathogenic and epidemiological characteristics of the pneumococcus. Some of the characteristics include the ability to cause invasive pneumococcal diseases and outbreaks and potential to cause immunological responses to vaccination and infection. Immunosuppression, antibiotic consumption, age, vaccination, ethnicity, geography and socioeconomic status are other factors that affect the pathogenic characteristics of pneumococcus. Temporal association with viral respiratory diseases has also been shown to play a fundamental role in the epidemiology of pneumococcal diseases.
Weinberger (2012) explains that there was a significant rise in pneumococcal-related hospitalization between August and December of 2009. The timing corresponded to the high pandemic H1N1 influenza virus activity. The geographical variation in these hospitalizations matched the influenza wave geographical patterns. The rise in hospitalizations was noted to be much higher among children and adults over fifty years of age. Simonsen’s (2012) research findings further support these facts in the US. A significant rise in pneumococcal pneumonia hospitalizations was observed in the autumn of 2009 that corresponded to the influenza pandemic peak period that year. The increase has been particularly high among school going children.
Research by Harboe in 2010 sought to evaluate the relationship between trends in Pneumococcal serotypes and influenza virus in Denmark in over seven decades. The results showed pneumococcal disease incidence peaks in 1957, 1969, 1996 and 2004 coinciding with reported influenza A epidemics. There was an increase in serotypes 4 and 9, a decrease in 18C while 6, 14, 7F and 23F remained constant between 1957 and 1969. Peaks due to Serotypes 12F and 1 continued to be observed after 1970. Pneumococcal diseases caused by 19A serotypes increased between 2003 and 2007. The study shows an increase in the incidence of pneumococcal diseases from the pre-influenza pandemic period to post-pandemic influenza pandemic period with different serotypes predominating in various pandemic seasons.
Introduction of 10 and 13-valent conjugate vaccines prompted a significant decrease in the incidence of pneumococcal diseases as well as changes in the distribution of serotypes in persons under 18 years (Grijalva, 2007). The vaccines are highly effective in reducing pneumococcal disease.
The incidence of pneumococcal disease increased significantly during and after the 2009 H1N1 influenza pandemic. This incidence and the above discussion indicate a high possibility of a relationship between pneumococcal disease and respiratory viruses. This possibility could explain Gonzales’ (2006) indication that there is need for vaccines that cover a wide variety of serotypes causing pneumococcal diseases is paramount.
References
Gonzalez, B. E., Hulten, K. G., Lamberth, L., Kaplan, S. L., Mason Jr, E. O., & US Pediatric Multicenter Pneumococcal Surveillance Group. (2006). Streptococcus pneumoniae serogroups 15 and 33: a decreasing cause of pneumococcal infections in children in the United States after the introduction of the pneumococcal 7-valent conjugate vaccine. The Pediatric infectious disease journal, 25(4), 301-305.
Grijalva, C. G., Nuorti, J. P., Arbogast, P. G., Martin, S. W., Edwards, K. M., & Griffin, M. R. (2007). Decline in pneumonia admissions after routine childhood immunisation with pneumococcal conjugate vaccine in the USA: a time-series analysis. The Lancet, 369(9568), 1179-1186.
Harboe, Z. B., Benfield, T. L., Valentiner-Branth, P., Hjuler, T., Lambertsen, L., Kaltoft, M., & Konradsen, H. B. (2010). Temporal trends in invasive pneumococcal disease and pneumococcal serotypes over 7 decades. Clinical Infectious Diseases, 50(3), 329-337.
Launes, C., García-García, J. J., Triviño, M., Peris, N., Pallarés, R., & Muñoz-Almagro, C. (2014). Respiratory viruses, such as 2009 H1N1 influenza virus, could trigger temporal trends in serotypes causing pneumococcal disease. Clinical Microbiology and Infection, 20(12), O1088-O1090.
Simonsen, L., Jordan, R., Steiner, C., Miller, M., & Viboud, C. (2012). Impact of the 2009 influenza pandemic on pneumococcal pneumonia hospitalizations in the United States. Journal of Infectious Diseases, 205(3), 458-465.
Weinberger, D. M., Malley, R., & Lipsitch, M. (2011). Serotype replacement in disease after pneumococcal vaccination. The Lancet, 378(9807), 1962-1973.
