Thursday, November 27, 2014

Eradicating Measles in a Puff of Air

Exciting news on the fight to eradicate measles came out this week with a new paper published by Robert Sievers and colleagues detailing the successful test of a new measles vaccine.

In their paper, published in the journal Vaccine, they detail the results of the first clinical trial using the new vaccine. What makes this so heartening is that the Sievers vaccine is a dry powder to be inhaled—no injections, no need to reconstitute the powder with clean water, easy transport and no sharps waste either. Their study showed that both men who received the typical measles injection and those who received the powdered form mounted similar immune responses.

This is great news for two major reasons: 1) the WHO announced this year that we are actually slipping the fight against measles, with significant increases in cases occurring over the past few years and 2) there remains a lot of misinformation and distrust around the current measles vaccine linking it to neurological issues like autism. Even though this connection has ben disproven over and over, many parents (especially in the US and Europe) refuse to vaccinate. The powder might prove to be an alternative they are willing to partake in.

Either way, this new vaccine is nothing to sneeze at.

Read the paper here: http://www.sciencedirect.com/science/article/pii/S0264410X14013620

---Lauren Sweet

Bird Flue Outbreaks


Two outbreaks of bird flu, the highly contagious and deadly H5N1 strain has been reported in India in the southern state of Kerla, one killing 15,000 infected ducks in Kottayam and another 500 in nearby Alappuzha. This is notable because, unlike most strands of bird flu, humans can catch H5N1. In 2005-2006 an outbreak occurred which spread to Asia, Africa, and Europe, resulting in the deaths of over 400 humans and millions of birds. Other strains, such as the H5N8 strain, which is currently in Europe and resulted in the killing of ducks and chickens in Germany, the Netherlands, and England are not as serious as they cannot spread to humans.

Outbreaks in animals do not always lead to outbreaks in humans, but an outbreak in humans is potentially deadly. Several vaccines are available and are in the United State’s national vaccine stockpile for emergency use, but are not a regularly given vaccine.

Madeleine Bousquet

Reference:

Monday, November 24, 2014

Why are people still refusing to vaccinate their kids against polio?

Since January, there have been more than 200 cases of polio in Pakistan. This level of cases has not been this high in fifteen years. Even with this knowledge of the rising number of polio cases, people still refuse to vaccinate their children. Some of this can be blamed on government mismanagement. But in many regions of Pakistan, many think the polio vaccination campaign is a western conspiracy to sterilize their children, an idea implemented by the Taliban. In 2012, Taliban militants ordered a complete ban on vaccinations in most regions of western Pakistan in response to drone attacks by the United States. According to UNICEF, this has led to nearly 300,000 children being un-vaccinated against polio. This is also worrisome because these poor neighborhoods are high risk for polio because of the lack of sanitation in the area.
 
Abrar Khan

The article describes the experience of Abrar Khan, 26 years of age, who traveled to the poor neighborhood of Baldia, Karachi. He contracted polio when he was three and now he is a part of a team trying to convince parents to vaccinate their children. He is accompained by armed policemen because without their protection they are at risk of being killed during their immunization campaigns. As he travels door to door, he is turned away as household members claim "I don't trust it" "Why are you after my grandchildren?" "My children don't need this, leave them alone!" "There are other diseases why are you focusing on this one?"

http://www.bbc.com/news/magazine-30133279

~Theresa

A Tiny Sea Monster On the Lose in the Eastern Pacific-- by Joe Getsy

During this class, we’ve mainly focused on viruses of humans and other primates (hence the name “Humans and Viruses”). However even viruses that don't infect people (like the papaya virus I looked at in a previous post) can still affect us indirectly. 

One such virus that affects a completely different group of animals has been on many marine biologists’ minds recently: a sea star parvovirus has caused millions of sea stars to, as one scientist so astutely pointed out, “fall apart into a pile of goo on the bottom of the seafloor” (http://www.reuters.com/article/2014/11/17/us-science-starfish-idUSKCN0J129K20141117). 

Obviously this is a much more pathogenic Parvovirus than Parvovirus B19, the pathogenic agent of 5th disease, a mild rash seen primarily in children (never too early to start reviewing: http://www.cdc.gov/parvovirusb19/fifth-disease.html).

They’re an important predator that acts as a keystone species in shallow water, so it’s important to protect these animals for the health of these ecosystems, which humans rely on. Additionally, they themselves provide food for Alaskan king crabs (a commercially valuable species known for its legs and feature show, Deadliest Catch) (http://www.adfg.alaska.gov/static/education/wns/alaska_king_crabs.pdf). The virus, sea star associated Densovirus (SSaDV), causes sea star wasting disease. The virus has been detected in museum specimens from as early as 1942. The particular strain responsible   for this epidemic was first spotted in August 2013 when divers noticed massive die-offs of the sunflower star Pycnopodia helianthoides near Vancouver, Canada. It doesn’t show any signs of slowing. Many species of sea star have been affected, including sun stars, (Orthasterias koehleri), giant pink stars, (Pisaster brevispinus), leather stars (Dermasterias imbricata), and bat stars (Patiria miniata).


It is possible that the virus mutated, or that increasing population density combined with changing water temperature and chemistry allowed the virus to cause an epidemic. This is the largest recorded natural die off of marine invertebrates, even larger than similar die-offs that occurred in 1970’s, 1980’s and 1990’s.
             

SSaDV is a parvovirus of the genus Densovirus. The team who discovered that SSaDV was the cause of sea star wasting disease used a similar process as the people who discovered tobacco mosaic virus (TMV); they could infect health sea stars with tissue biopsies of infected ones, and found that the viral load in recently deceased sea stars was much higher than it was in healthy ones.


 
Healthy sunflower star  Pycnopodia helianthoides
An unidentified species of diseased sunflower star... yuck!














Science, Funding & Public Policy: The Real & Unfortunate Fuzzie-Techie Divide?

Last Thursday, I was lucky enough to go to the roundtable, "Global Health Crises: How Scientists Can Shape Policy," which was organized by one of my friends. Dr. Bob was one of the four speakers at this event, and it prompted me to consider what the responsibilities of scientists are to contribute towards public policy. The panelists mentioned several times that the government often plays catch up from science, especially since most government officials have little to no background in science. This highlights a fundamental setback of the political system; many important decisions are made by politicians, and it is the responsibility of scientists to provide as much information as possible to inform those with decision-making power correctly. The government actually gets its information from the National Academy of Sciences; you can read more here about this body, which calls upon researchers and scholars from several disciplines, to share their research. http://www.nasonline.org/about-nas/mission/. Over 6,000 experts work, on a volunteer basis, to provide the scientific background behind some of the most pressing social issues with scientific backgrounds. The question is -- is this enough to make the most informed decisions?

Another particularly interesting point from the panel was the funding disparities between different national and international healthcare bodies. The panelists mentioned that Stanford hospital has a higher budget than the WHO; the same follows for the CDC. The budget disparity is multiple-fold, and this controls the impact that these institutions are able to make. Dr. Michele Barry noted that the WHO is "broke" or "broken," especially because funding sources dictate their research interests. Institutions like the WHO have so much international pressure from the public to respond to crises, but because of their lack of budget and personnel, they are limited to act as an advising body rather than a responding body. I took some time to look up the WHO budget for 2014-2015; the total proposed program budget for this two year span is 3.977 billion US dollars. Their funding sources are divided between various priorities, including communicable diseases, noncommunicable diseases, health through the life-course, health systems, preparedness/ surveillance/ response, corporate services / enabling functions, and emergencies. From 2012-2013 to 2014-2015, there was actually a 7.9% decrease in funding in communicable diseases, which include a lot of viral diseases (like Ebola). The bud

If you're interested in reading more about the budget, here is the official PDF of the funding distribution. Within this report, there is a lot of information regarding the deliverables and targets of the WHO, which prompts the question of how all of that can be achieved to obtain the best health outcomes given a constricted budget. http://www.who.int/about/resources_planning/PB14-15_en.pdf?ua=1

Overall, the panel really prompted me to think about the duties of scientists, beyond the space of their own research, to contribute to the world of policy research and development. It is critical that those in positions to make important decisions are informed enough to allocate funding and working power towards solving the health crises of today and tomorrow.


-- Nicole

Friday, November 21, 2014

Ebola Treatment Heading to Clinical Trials


   Yesterday in class we discussed when Ebola treatments would be heading to trial. Here's an article describing some of the difficulties that have arisen so far.

    There are 4 unproven treatments available: TKM-Ebola (inhibits viral RNA), plasma from recovered individuals (has antibodies specific to Ebola virus), brincidofovir (a drug developed for other viral infections but shown to be effective against Ebola), and ZMapp.



   On November 13,2014, Doctors without Borders (MSF) started 3 trials for treatments. The question this raises is, "is it ethical to have a control group that doesn't get the Ebola treatment?" I don't think it is. MSF agreed and made their studies with an alternative design so that everyone receives treatment. Now, there's the problem of the fact that we don't have a control group and we may not get clear answers from this study now.

Update: The trial is not random. MSF will compare survival data of all patients that now receive Ebola treatment to the survival data of all previous patients before they had Ebola treatment options. Obviously this raises many problems and defies everything about RCTs, but it seems like this is the best option.

The next step after these clinical trials is making these drugs affordable, produced, and then distributed.

Have a great Thanksgiving break yall,
Jimmy



http://www.sciencemag.org/content/346/6212/908.full

Thursday, November 20, 2014

Let’s Talk About Eradication: Polio Type Three

A child receives the OPV
This week’s Morbidity and Mortality Weekly Report from the CDC indicates progress towards eradication of the third serotype of polio, wild poliovirus 3 (WPV3).

In the report, the CDC explains that regions are only designated as polio free if 3 or more years have passed since the last case of poliovirus. The Americas, Western Pacific Region, European Region, and the South-East Asia region have been certified as polio-free. Since then, the World Health Organization has turned its attention to the remaining endemic countries: Nigeria, Afghanistan, and Pakistan.  

Interestingly, no new cases of wild poliovirus 3 have been observed for two years, since November 2012. In addition to the absence of new cases, the World Health Organization has reported that the genetic diversity of collected WPV3 samples has diminished since eradication efforts first began, further suggesting that viral replication and persistence of WPV3 has similarly diminished. (Genetic diversity is characterized as having a genome that is at least 15% divergent from other strains.)

The WHO monitors polio by monitoring the number of cases of acute flaccid paralysis in the world, in addition to testing sewage samples for the poliovirus. Monitoring and surveillance programs in Pakistan and Nigeria have been improved, adding further credibility to recent evidence.

According to the report, an effective elimination strategy has been switching to bivalent polio vaccines for types 1 and 3 instead of immunizing with monovalent or trivalent vaccines for types 1, 2, and 3.

The report concludes by acknowledging that continued surveillance is necessary to confirm eradication. If successful, this will be the third time a human pathogen will have been eradicated (including smallpox and WPV2).  



-Luis Garcia