Tuesday, February 21, 2017

Epstein-Barr Virus: Carcinogen Found

The oncogenic associations with Epstein-Barr Virus (EBV), a member of the Herpesviridae family, have been studied in great detail. But key pieces of information are still missing. What exactly does EBV do to cause cancer? What molecular mechanism does it work by?

A collaboration between Henri-Jacques Delecluse and Ingrid Hoffmann, researchers at the German Cancer Research Center (Deutsches Krebsforschungszentrum, DFKZ) has uncovered a potential lead. The viral protein BNRF1 induces constitutive formation of spindle poles, or centromeres. The consequence is that, during mitosis, when chromosomes should make copies of themselves and then split into different cells, chromosomes divide unequally. This increases the risk for cancer, as unequal division of chromosomes can lead to mutations.

To study this, the cancer researchers synthesized BNRF1-deficient EBV and observed that the heightened number of spindle fibers was no longer present in infected cells.

BNRF-1 is present in an infectious EBV particle. This means that the EBV genome is technically not needed for oncogenesis. The finding suggests that a vaccine is much-needed, as a successful vaccine would allow the formation of memory antibodies that can neutralize infectious particles.

News Article:
Press Release from the DFKZ:

-- Sharon Kam

San Francisco En Route to Eliminating HCV

For a long time, Hepatitis C has been a tricky disease to treat. A viral infection that, in 85% of cases, transitions into a chronic condition associated with long-term health consequences, there was no vaccine nor specific antiviral therapy to cure HCV infection. The treatment plan included a full year of chemotherapy, was fraught with side effects, and only had a 50% success rate.

This all changed three years ago, when Gilead Sciences developed an effective (95%!) hepatitis C cure, Sovaldi. Sovaldi is given in pill form, but the catch? It's wildly expensive. The 12-week treatment course will cost a total of $84,000, as pills are priced at $1000 each. 

Despite the expensive nature of treatment, San Francisco has announced an initiative to eliminate hepatitis C. The first in the country, End Hep C SF will work to identifying everyone infected with HCV and getting them through the 12-week regimen. The initiative will likely have a hard time convincing insurers to pay for it all, but healthcare has learned that early prevention is the key to cost-saving for later on. Eliminating HCV will prevent future transmission of the disease, reducing the amount needed to spend in the future. 

Of interest, End Hep C SF will also be working to provide treatment to at-risk communities. One clinic, Healthright 360, serves members of these at-risk communities and is preparing to provide the 84-day hepatitis C treatment to those that enter 90-day treatment programs.

Will San Francisco succeed in its ambitious task? It certainly would be a good example for the rest of the country, and perhaps lead to the eradication of another virus. 

SF Chronicle News Article: 
On Sovaldi and other HCV drugs by Gilead:
Hepatitis C Virus FAQ:
Healthright 360:

-- Sharon Kam

H7N9 Risks and Comparison

A recent article in Reuters has argued that due to our inability to easily see H7N9 in poultry, it may be more common than formerly expected.  For reference, H7N9 is an avian subtype of influenza A not to be confused with H5N6, another subtype.  The difference between these two subtypes can be seen easily in their fatality in humans.  The latter struck South Korean poultry at the end of 2016 and led to massive culls of birds, but no human deaths.  On the other hand, the former, H7N9 has been fatal in 100 or more people in the last few months, but is often asymptomatic in the birds that it infects.

Though unable, at this point, to spread via human to human contact, H7N9 can be easily passed between birds and it is interactions with these infected birds that lead to human infection.  Because of this, the CDC labels H7N9 has being low risk, but marks it (on its Influenza Risk Assessment Tool) as the influenza subtype with the greatest potential to cause a pandemic.  Because of this potential, the CDC is keeping an eye on H7N9 and preparing for it by checking the H7N9 candidate vaccine viruses to see if they need to be updated for the latest epidemic and seeing if the latest strains of H7N9 are still susceptible to the neuraminidase inhibitors we have available.

Devon Z.

RRV Strikes Victoria, Australia

Last mentioned on the blog in March of 2015, Ross River virus (RRV) has returned in force to Victoria, a state in Australia.  Since the beginning of the year, there have been 1012 cases in the state, with over 150 found to be infected in the last week.  These are record numbers in infection, dwarfing even 2010, when the outbreak was notable due to widespread flooding that provided breeding grounds for the mosquito vectors that transmit the virus.  Similarly, the reason this year has been such a large year for Ross River virus is due to extended rain and a number of warm, summer days that have been a boon to mosquito reproduction.

In order to combat the mosquito vectors, the Victorian Health Department has employed over $4 million dollars in emergency funds to eliminate standing water and spray for mosquitoes, among other activities.  They are also encouraging many common mosquito bite prevention techniques:  putting screens on windows, wearing long sleeves and pants, dumping out standing water, and using repellent.  

There are 40 or more species of mosquitoes that may transmit this alphavirus (of the Togaviridae family) with those of the Aedes and Culex genera being the most prominent.  In addition to having a wide range of vectors, RRV has a number of animal reservoirs, including wallabies, kangaroos, horses, and humans.  The latter of which has likely been involved in outbreaks where few animals are found, such as in urban centers.

Devon Z.

Saturday, February 18, 2017

Seoul Virus Outbreak Update

Seoul virus has been found in a pet rat at a breeder’s in Pennsylvania.  This rat came from Tennessee where other Seoul virus infections have been found, so the rat was likely infected there.  In order to stop the spread of the virus further, the rats at the breeder’s in Pennsylvania were euthanized.

Overall, this is yet another finding of Seoul virus in pet rats connected to an outbreak that originated in Colorado breeding facility.  This outbreak, in addition to the infections mentioned above and in a number of other states, has led to 13 human infections.  Human infection can follow after exposure to infected rat feces, urine, blood, or saliva.  These exposures can happen due to the inhalation of infected particles, rat bites, or the consumption of contaminated food.  And after an incubation period of 7-14 days, human infection manifests with flu like illness, with others being asymptomatic, and others requiring more serious medical assistance for kidney problems.

- Devon Z.

Oral Norovirus Vaccine in the Works

A norovirus vaccine is gaining momentum as it just finished its Phase I trial.  This vaccine, produced by Vaxart, is unique in that it is an oral, recombinant vaccine that is given as a tablet.  Vaxart is a local biotech company that is striving to produce oral tablet vaccines for RSV and seasonal flu, in addition to Norwalk virus.

The norovirus vaccine Phase I trial was looking primarily at safety and whether or not the vaccine produced the desired immune response.  This trial contained 66 subjects, with 46 receiving the vaccine and 20 receiving the placebo.  Safety wise, there were no serious adverse events reported and the vaccine appeared to be “well tolerated in all subjects.”  Additionally, the vaccine appeared to do what it set out to accomplish and boosted norovirus antibodies along with “a local intestinal immune response.”  In doing so, the vaccine achieved all of its desired endpoints for the Phase I trial.

- Devon Z.

Friday, February 17, 2017

South Korea facing a Foot-and-Mouth Disease Outbreak

South Korea is currently facing a couple of cases of foot-and mouth disease amongst some cattles and the agriculture ministry is increasing its concern for the viral disease. The ministry announce this past Monday that it would be importing close to 5 million doses of the vaccine within these next two weeks in order to hopefully prevent a possible outbreak. The deputy of the food industry, Kim Kyeong-kyu, announced at a briefing this past week that they are “raising the alert level as foot-and-mouth cases occurred at different parts of the country and a second type of the disease emerged.” As of this 2 weeks ago, at least 1,2000 cattle have been slaughtered, which is about 0.04% of the cattle population.

Foot-and-mouth disease is caused by a picornavirus and affects cloven-hoofed animals. It is highly infectious and can be transmitted through aerosols and close contact, which can be very problematic among susceptible animal herds (cattle, sheep, goats, deer) within farms. This disease usually results in high fevers, weight loss, swelling of testicles, and could potentially lead to myocarditis and death. Transmission to humans is rare so the main concern with this viral disease is because of its high spread among animals.

Therefore, South Korea is quickly responding to the outbreak with 5 million doses. The vaccines will be against the O and A type strains of the virus, which are the two strains that have been identified. The government believes such vaccination will prevent the further spread so let us hope it all works out!

-Jeanette Rios ('18)