PertussIssues...

Pertussis is currently a very hot topic although many really don’t know what it is. Currently things are being done in an attempt to stop the spread of the disease.

Pertussis and Politics

Many may think science and politics are two completely different fields that never intersect. Although they are two very different areas of focus, they actually intersect quite frequently. We see example of laws being passed for things like the environment. In Virginia, it is required by law to have your car looked at and emissions checked. Well they do the same sort of thing for diseases as well, especially with pertussis. In 2010, Assembly bill 354 was signed into law. This law stated that students entering or advancing in grades seven through twelve are required by law to show proof of immunization with a pertussis vaccine booster called, tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine, more commonly known as the Tdap. Many think the government is over bearing and should have no right passing bills that require them to inject their children, but what people don’t realize is that these bills effectively aid in combating pertussis.

Rise Against the Vaccine

The very problem we have now is people refusing to get their children vaccinated. As stated above only grade seven through twelve are required of show proof of vaccination. This means parents of children younger than this range can opt out of the vaccination altogether until the seventh grade is reached. Here in lies the problem. People refuse to get vaccinated because there have been reports 

linking these vaccinations with Autism. A report from the FDA in 2005 outlined a number of adverse side effects coming from the Tdap booster. One of those adverse side effects was autism. This idea was proposed by British former surgeon and researcher, Andrew Wakefield. These reports have since been debunked, but the thought of a vaccine causing Autism still makes ill-informed people not get their kids vaccinated,

which ultimately aids the spread of the disease. People believed certain ingredients in the vaccines were the source of the problem One ingriedient in question was thimersoral. Thimersoral was used as a preservative in many childhood vaccines. Contrary to popular belief, it was removed from vaccines in 2001. Many studies have since been done and there were no trends found supporting a link between thimersoral and autism. The Institute of Medicine (IOM) have done several studies and published a scientific review stating there is causal relationship between thimerosal–containing vaccines and autism. Furthermore, the Centers for Disease Control and Prevention support the findings of the IOM.   

The Verdict

Although many studies have been done disproving the fact that vaccines, including pertussis, can cause Autism, many for some reason still believe they do. It is important to note that Andrew Wakefield’s published paper, stating vaccines cause autism, has since been retracted because he falsified his findings. He has also lost creditability as a research, yet people still stand by his findings. People cannot continue to make decisions that can have serious consequences while being uninformed. Hopefully if there is anyone out there who believes vaccines are detrimental to child health, they should at least do some research before they make a particularly risky choice.  

References

Concerns About Autism. (2014, November 18). Retrieved November 26, 2014, from http://www.cdc.gov/vaccinesafety/concerns/autism/

Pertussis (Whooping Cough) Vaccine Requirement. (2014, August 28). Retrieved November 26, 2014, from http://www.cde.ca.gov/ls/he/hn/pertussis.asp

 

Origin of an Epidemic

It is no secret that Pertussis, or whooping cough, is a prevalent disease in society today. If you don’t know see my previous posts and it should give you some kind of idea. It is particularly interesting to try and find the origins of diseases and this is what my article outlines. In my previous post I talked about a key player in the pertussis fight, Dr. Julian Parkhill. I also mentioned some recent research he had done about finding the origin of the disease. This article is the published paper in which Parkhill and his team show their findings.

The Article

The article in question is titled Impact of Whooping Cough Vaccination:Comprehensive Study Shows Effect of Vaccination on Spread of Bordetella pertussis. The article is very recent and was published on April 23, 2014. I found it through ScieneDaily. The author was the Wellcome Trust Sanger Institute in Cambridge, UK. Led by Parkhill, they embarked on a detailed study of the family of bacteria that causes pertussis.

What They Did?

Researching the origin of a disease is no easy task. It takes a lot of time and patience. It is a lot like putting together a puzzle, except in this case there are many pieces and instead of just putting the pieces together you also have to think about the bigger picture and compare the various aspects of each piece. They used genomic analysis, which is basically finding and comparing the order of a DNA sequence. Parkhill et al. collected 343 strains of Bordetella pertussis bacteria from the past 100 years. The different strains also came from around the world so they could get a wide range of the bacteria. Through many methods and procedures, they compared these strains and were able to get a better idea of the origin of the disease, but the result was very shocking to the researchers.

What They Found?

Researchers were ultimately shocked with their findings. Originally, researchers though the disease was tens of thousands years old.  From the study, they concluded that the pertussis bacteria actually evolved relatively recently. They narrowed down the data and found the disease was actually first Identified only 500 years ago in Paris, France. They note the only previous mention of the disease was from a 15^th century Korean medical textbook, but no actual human cases were identified then. They also found the mutation rate of pertussis being slow and mention it may be a contributing factor to the resurgence of the disease currently.

Future Implications

So they found out where a disease came from, who really cares? Finding origins of diseases actually points to future actions that can be taken. Currently used strategies have not completely ridded us of pertussis, but instead allowed enough leeway for the disease to mutute, resulting in a number of variations. This study really allows researchers to see the path that the pertussis bacterium has taken since its emergence. It allows a vision of previous mutations and trends, which ultimately allows researchers a better picture of how to get rid of the disease. This study will allow researchers to make more effective vaccinations that will ultimately lead to the decline of pertussis. 

Reference

 Wellcome Trust Sanger Institute. (2014, April 23). Impact of whooping cough vaccination: Comprehensive study shows effect of vaccination on spread of Bordetella pertussis. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2014/04/140423095206.htm

 

Parkhill vs Pertussis

There are many researchers in the field of pathogen genomics. Pathogen genomics, also known as Pathogenomics, is the utilization gene sequencing and phenotyping in order to understand microbe diversity and interactions. Pathogenomics can tell us many things such as, pathogen variations, virulence and transmission factors, as well as evolutionary features of pathogenicity. A key researcher in Pathogenomics is Dr. Julian Parkhill.

Dr. Julian Parkhill

Who is he?

Dr. Julian Parkhill is modern day scientist and the head of Pathogenomics at the Wellcome Trust Sanger Institute in Cambridge, UK. Parkhill received his PhD from the University of Bristol in 1991. He specialized in research of bacterial resistance to mercury and copper.

Approach to Research

Parkhill’s research team at the takes a “broad and deep” approach to their analysis of pathogen genomes. By “broad,” it is meant that they analyze a wide variety of human and animal pathogens. They take this approach because it allows them to study the wide variety of both human and animal pathogens in order to study the wide variety of mechanisms used to both infect a host and cause disease. This study technique allows researchers to compare and contrast specific characteristics at the core of pathogens allowing them to analyze functions responsible for interaction to specific hosts.

The “deep” aspect refers to the numerous characteristics associated with very closely related strains in a given species, or group of species. Bacteria have many different characteristics, which allows them to be so versatile and come in so many different varieties. Examining in such detail allows Parkhill’s team to draw inferences on questions such as: How or why do pathogens select certain hosts? How have they evolved? Does variation correspond with virulence? These aspects also play certain roles in transmission and treatment or drug resistance of pathogens ("Dr. Julian Parkhill," 2014).

Impact on Pertussis Research

From 2013 to 2014, Parkhill led a handful of scientists at the Wellcome Trust Sanger Institute in Cambridge, UK. Together they pulled a few hundred samples of Bordetella pertussis, the bacterium

Evolutionary Tree created by Parkhill et al

that causes pertussis, and worked to create an evolutionary phylogeny, or family tree, of the bacteria. From the study, they concluded that the pertussis bacteria actually evolved relatively recently. They were surprised to discover that the ancestor of modern-day pertussis emerged spontaneously in the 15^th or 16^th century.  It was noted that the distinctive cough was first encountered in a Korean medical text in the 15^th century. The first actually documented epidemic was in 1578 in Paris, before these events there is no trace of the disease having existed. Parkhill et al. (2014) also found that the human virulent seems to have evolved from the mutation of a closely related bacterium found in dogs, rabbits, and many other animals. The analysis also suggests pertussis, remained hidden for thousands of years before it burst out as a full-fledged human disease (2). Most importantly conclude from the study was the ability of the bacterium to evolve which is why the current vaccines are not working as well as they used to. I mentioned the pertactin lacking strains in my previous post and this is one factor attributed to the current outbreak. Fortunately, pertussis does not mutate as fast other diseases, such as the flu, which makes it a little easier to control and create vaccines to combat it. This research was vital in terms of gene sequencing and pointed to more effective vaccinations for newer strains as well us shocking, unknown evolutionary history of a deadly disease.  

For some reason it would not let me embed the video on the page, but the link to a short, 1 minute video, outlining the human genome, is below. The video is done by Julian Parkhill.

https://www.youtube.com/watch?v=M_Tj6p_8PfU

References

Collins, J. (2010, April 27) Genome Explained [Video File]. Retrieved from YouTube.com 

Dr. Julian Parkhill. (2013, September 23). Retrieved November 19, 2014, from https://www.sanger.ac.uk/research/faculty/jparkhill

Harris, R. (2014, April 25). Family Tree Of Pertussis Traced, Could Lead To Better Vaccine. Retrieved November 19, 2014, from http://www.npr.org/blogs/health/2014/04/25/306845814/family-tree-of-pertussis-worked-out-could-prompt-better-vaccine

Julian, P. (2014, April 23). Impact of Whooping Cough Vaccination: Comprehensive Study Shows Effect of Vaccination on Spread of Bordetella pertussis. Retrieved November 19, 2014, from http://www.sciencedaily.com/releases/2014/04/140423095206.htm