Malaria, Safari Science, & Global Public Health Spending

 

Rhoel Dinglasan & Clive Shiff
Rhoel Dinglasan & Clive Shiff, Malaria Researchers at Johns Hopkins School of Public Health (1)

We are pleased to announce Expert Panel #2:
“Malaria, Safari Science, & Global Health Spending” recorded on  May 3, 2013. Guest experts Drs. Clive Shiff (JHMRI), Rhoel Dinglasan (JHMRI), & Jim Webb (Colby College) share diverse perspectives on why malaria is so hard to control.

To listen to the podcast, right click to download or click to stream. Also available on iTunes here.

Nina for one is new to the International & Global Health fields. If you are in the same boat, the following links will be helpful to understand the discussion. An article on vertical versus horizontal public health programs is also in the works.

Malaria and other global infectious diseases: why should we care? by Sean Murphy
Johns Hopkins Malaria Research Institute: Life Cycle of The Malaria Parasite & links to researchers at JHMRI
Dr. Rhoel Dinglasan’s Lab Website: http://www.dinglasanlab.org/
What is the Roll Back Malaria Partnership? http://www.rbm.who.int/rbmmandate.html
History of Public Health Timeline, Interactive Map by The North Carolina Institute for Public Health
“In pursuit of better global health, should we follow a horizontal or vertical approach?” by student blogger at NYU-Wagner/Global Health Policy class
Free Online Global Health Course: Module 4: Eradication Efforts: Malaria versus Smallpox
Dr. Jim Webb’s Book: Humanity’s Burden: A global history of malaria

Jim Webb pic

Jim Webb pic

(1) Photo courtesy of Johns Hopkins Magazine article featuring Clive & Rhoel.

Historical Epidemiology of Malaria Control

What can current malaria and other public health researchers learn from past eradication attempts? This is the subject of last week’s Friday Malaria Seminar at the Johns Hopkins Malaria Research Institute given by guest speaker Dr. James L.A. Webb Jr., PhD, MA, Professor, Colby College, Department of History. His talk, “The Historical Epidemiology of African Malaria 1945 – 1965,” gives us a sneak peak at his newest book coming out next year. Introduced by renowned malariologist, Dr. Clive Shiff. NB: Dr. Webb is Nina’s former undergraduate adviser, mentor, and friend and is also featured on this month’s Expert Panel #2 podcast along with Drs. Shiff & Rhoel Dinglasan.

Click here to listen or right click to download. Available on iTunes here.

Here’s Dr. Webb’s page at Colby College and here’s his website with links to his book Humanity’s Burden: A Global History of Malaria.

Jim Webb pic

Are we close to curing AIDS?

This week the New York Times published an excellent article putting in context many of the recently reported breakthroughs on HIV/AIDs research. The article details three exciting developments in HIV research that have occurred over the last few years.

One of these is the famed Berlin patient, actually a 46 year-old American named Timothy Ray Brown. Mr. Brown was already HIV+ when he was diagnosed with leukemia and received in a bone marrow transplant in Berlin in 2008. Mr. Brown’s bone marrow donor happened to have a rare genetic mutation that makes his cells resistant to infection by HIV. Mr. Brown, following the transplant, has reaped this benefit, and is HIV and symptom-free five years later, and with no anti-retroviral treatment.

The second development detailed was the “functionally cured” baby described in a PHU post by Nick last month. This baby was born HIV+ but immediately given anti-retroviral therapy. Almost a year later without continued treatment, the baby remains virus-free. The third development came out of France last year when 14 individuals were identified as HIV-free two years or more after stopping treatment. All of these reports demonstrate that the outcome of interaction between HIV (or any virus) and the host is always defined by the unique genetics of each individual, as well as by the virus.

Current anti-retroviral treatment can target many stages of the HIV lifecycle, but the goal is to prevent replication of the virus. We still don’t know how to train the immune system to kill infected cells that constitute the reservoir of HIV in a host. Understanding how the immune systems of these individuals not only prevented HIV replication but actually cleared the virus may allow us to adapt these strategies for use in the vast majority of HIV+ individuals who will require lifelong anti-retroviral therapy. Funding this kind of basic research and applying its findings to the clinic may, one day, save millions of lives.

-Steve

What Is Cancer? An explanation for the non-scientist of the biology behind cancer

Curious about what cancer really is? Here is the first of a series of articles explaining the science behind cancer.  This is by no means an exhaustive background, but we hope this will help you understand the cancer research presented in the news and perhaps help you spot misinformation.

Please let us know if you have more questions or want something clarified. We are also working on a glossary–let us know if you have terms you want included!

Public Health and Diseases of Food

For those of you that took our advice and have been looking at ProMED-mail for a good source of science/disease outbreak news (or for those who were already doing so), you may be noticing a lot of outbreaks for animal and plant diseases.

One Health, which Stephanie Porter brought to our attention in the first News Analysis episode, figures prominently into this. Many of the diseases that infect humans are zoonoses (disease transmitted from animals to humans or from humans to animals). Wild and domestic animals provide a possible source for new human diseases (think SARS and avian influenza), and to be truly healthy as people, we have to be mindful not to harm the health of animals.

A more important impact that animal and plant diseases have is their role in agriculture. Most food we consume is produced in monoculture (the growing or raising of a single crop or animal species in agriculture). For example, the corn we consume is made up of a few different strains of genetically identical organisms. This means that they susceptible to the same infectious diseases. A single germ can potentially wipeout a large area of corn monoculture.

For example, there was a recent ProMED-mail post about Schmallenberg virus and its recent reemergence in parts of Europe. The virus is a disease of ruminants, including cows, sheep, and goats, and it is relatively mild in nature except that it causes congenital defects in animals born to infected mothers. This can have devastating consequences on future food reserves.

So while human diseases and outbreaks are undoubtedly important to our health, animals and plant infections that may either spread to humans as zoonoses or wipeout our food sources are also important to the health and wellbeing of humans.

-Nick Wohlgemuth

The deal with ricin

So ricin is back in the news this week, but what is it, where does it come from, and why is anyone worried about it? Ricin is an extremely potent toxin derived from castor beans, and is a natural byproduct of castor oil production. It’s also long been a favorite of bioweaponeers, aspiring terrorists, and anti-government reactionaries.

We don’t know exactly how to derive ricin from castor beans (and wouldn’t tell you if we did), but it apparently isn’t that difficult. However, creating a ricin preparation that can be easily inhaled is considerably more difficult. This week’s ricin mailer apparently failed to overcome that obstacle, and we understand that the granular powder in the envelopes he sent was unlikely to be dangerous for this reason.

Ricin works by entering cells and binding to ribosomal subunits. This prevents cells from making new proteins and leads to cell death and, within 72 hours of exposure,  death of the poisoned individual. Fortunately, natural exposure to ricin is exceedingly rare, but successful and unsuccessful attempts to use it as a weapon are well documented.

Ricin is perhaps most famous for its role in one of the murkiest Cold War spy stories. In 1978 Bulgarian dissident Georgi Markov was walking over a bridge in London when he felt a sharp jab to the back of his leg, then turned to see a man behind him fumbling with an umbrella. Four days later he was dead. Investigators extracted a ricin-loaded pellet from the back of his leg, where the fumbling man had jabbed him with a spring-loaded umbrella.

Ricin has also popped up in other nefarious plots from time to time. In 2003 ricin-laced letters were detected in the White House mail, as one was this week. In 2006 a Virginia man was arrested for extracting ricin to use against his wife. Other cases involving ricin include elaborate plots to use ricin to assassinate public figures, but fortunately none have come to fruition.

The media isn’t wrong to treat these latest ricin letters as a serious matter; any time a dangerous toxin is sent to the President it’s important. However, they’re not making it very clear that you have nothing to worry about. That said, ricin poisoning is a life-threatening medical emergency, but if you’re concerned about it happening to you, the CDC FAQ page will hopefully persuade you otherwise, and will certainly tell you what to watch out for. Assuming you trust the people around you, don’t go on castor bean eating binges, and haven’t run afoul of Russian intelligence, ricin poisoning need not be high on your list of concerns.

-Steve

 

One Health & How Better Communication Can Help Limit West Nile Virus Outbreaks by Stephanie Porter

The One Health Initiative is the effort to increase communication and collaboration between disciplines such as human medicine, veterinary medicine, public health, environmental health, and other related fields 1. The hope is that by promoting collaboration, shared knowledge could improve the health of all species.

There are innumerable reasons why sharing knowledge between scientific disciplines is vital. Comparative medicine relies on the shared characteristics between the anatomy and physiology of humans and other animals, as well as similarities in disease pathogenesis. This knowledge is then used to establish animal models for biomedical research, which can help in the development of drugs, vaccines, medical devices, and increase understanding of infectious diseases and cancer. Identifying animal models that accurately reflect human disease is key, and requires input from those with knowledge of the physiology and pathology in both humans and potential animal models.

The large and increasing prevalence of zoonotic diseases is another reason why cooperation between human and veterinary medicine is of utmost importance. Of all the diseases which affect humans, ~60% are caused by pathogens which also infect non-human animals 2. Zoonotic diseases have become more problematic in recent decades, as ~75% of the infectious diseases that have emerged in the human population in the last 30 years have been zoonotic 2. Goals of the One Health initiative include improving surveillance, prevention, control, diagnosis, and treatment of zoonotic disease through joint efforts from various health disciplines, especially veterinary and human medicine.

The events surrounding the emergence of West Nile virus (WNV) in the United States in 1999 provide some of the best evidence that human and animal medicine have remained too distinct. WNV first entered the US in New York City during the summer of 1999. Crows, now known to be one of most highly susceptible North American WNV hosts, began dying in large quantities in June, but the New York state wildlife pathologist misdiagnosed 400 crow samples 3. Birds at the Bronx Zoo began dying on August 10th; by September 23, the zoo had lost a total of 27 birds 4. It was the zoo’s pathologist, Dr. Tracy McNamara, who started putting the puzzle pieces together when she realized that the encephalitis she was seeing in her birds may have something to do with the human disease outbreak that the city announced on Labor Day, which was misattributed to St. Louis encephalitis (SLE). She knew that her animals could not be dying from SLE, as it is generally asymptomatic in birds 3. Dr. McNamara appealed to both the USDA and the CDC to test her samples, and was met with resistance. One of the main problems she faced was jurisdictional, as neither government department wanted to claim responsibility for the health of wild and exotic species 5. People also did not want to believe that there was a link between the avian deaths and the human disease. Dr. McNamara finally got the Army to test her samples, and it was discovered that it was West Nile virus that was the causative agent. By that point it was September. In 1999, 62 individuals were infected with West Nile virus, 7 of whom died, statistics which may have been lower had there been more rapid identification of WNV 6.

Developing an effective surveillance program for West Nile virus activity took time, and retrospective analysis from avian samples collected during 2000 has revealed that WNV was evident in samples at least 2 weeks before the first human case 7. However, WNV birds were collected 3 months before the first human infection, so if laboratory testing had been conducted more swiftly there might have again been more advanced warning, and prevention of human disease 8. Today, WNV surveillance data is collected for human infections, sentinel chicken flocks, mosquitoes, veterinary cases, and dead birds (which rely on public reporting) 6. In 2012, there was a large WNV outbreak, resulting in increased avian and human deaths. The data has not yet been finalized, but the confirmed 5,387 human infections and 243 human deaths represent the most severe seasonal WNV epidemic since 2003 6.

Given the prevalence of zoonotic diseases, it would be impossible to have healthy people without also ensuring the health of other animals. That’s one of the reasons I get upset when I hear professors at JHSPH say things along the lines of “since this is a school of public health, obviously we’re going to focus more on human health.” We understand that multihost pathogens cannot be generally eliminated if you only focus on control in a single host, so I believe that public health is doing human health a disservice if it narrows its focus and ignores other species.

One Health is by no means a new concept, but one that has taken on increased importance given the globalization of our world, the growing prevalence of zoonotic infectious diseases, and the use of animal models in biomedical testing. Facing emerging medical problems as a collective force is perhaps the best way for all health professionals to ensure the well-being of all animal species, including humans.

1. One Health initiative. http://www.onehealthinitiative.com/.

2. King LJ, Anderson LR, Blackmore CG, et al. Executive summary of the AVMA One Health initiative task force report. J Am Vet Med Assoc. 2008;233(2):259-261.

3. Keynote by Dr. Tracey McNamara — 2012 Zoobiquity conference. http://www.youtube.com/watch?v=cBk9X4iwhmE. Updated 2012.

4. Steele KE, Linn MJ, Schoepp RJ, et al. Pathology of fatal West Nile virus infections in native and exotic birds during the 1999 outbreak in New York City, New York. Vet Pathol. 2000;37(3):208-224.

5. Microbeworld Video. One Health and the lessons learned from the 1999 West Nile virus outbreak (MWV46). http://www.microbeworld.org/podcasts/microbeworld-video/898-one-health-and-the-lessons-learned-from-the-1999-west-nile-virus-outbreak-mwv46-. Updated 2011.

6. CDC. West Nile virus. http://www.cdc.gov/ncidod/dvbid/westnile/index.htm. Updated 20122013.

7. Mostashari F, Kulldorff M, Hartman JJ, Miller JR, Kulasekera V. Dead bird clusters as an early warning system for West Nile virus activity. Emerg Infect Dis. 2003;9(6):641-646.

8. Eidson M. “Neon needles” in a haystack – the advantages of passive surveillance for West Nile virus. West Nile Virus: Detection, Surveillance, and Control. 2001;951:38-53.

 

Avian Flu Update

Since our first post the scale of the H7N9 avian flu outbreak in China has continued to increase. Authorities are now reporting 63 cases and 14 deaths (Update-now 77 cases, 16 deaths), and Beijing has also reported its first case. Additionally, thanks to the rapid work of Chinese researchers, we have learned a lot about this novel virus. Some of the information we have learned about this virus is certainly worrisome, but it’s extremely important to understand that neither the WHO nor the Chinese government have found any evidence of sustained person-to-person transmission. This means that while the number of cases is increasing, all cases are believed due to transmission from an infected bird to person, or perhaps limited transmission between people with extensive close contact, such as family members.

Researchers at the Chinese Centers for Disease Control and Prevention have published their initial, but extensive analysis of the H7N9 virus in The New England Journal of Medicine. Interpreting these findings requires knowledge of some basic virology, which we’ll try to keep to the basics. Those desiring a more technical explanation of influenza virus structure, lifecycle, and disease should look at Influenza 101 on Dr. Vincent Racaniello’s virology blog.

H7N9 denotes the subtype of influenza virus as defined by the two main proteins on the surface of the virus, HA and NA. Human influenza viruses are typically H1 or H3, whereas avian viruses include H5 and H7, among others. Unlike most viruses, which have a genome consisting of either one or two strands of RNA or DNA, the influenza virus genome consists of eight separate RNA segments, each of which directs the production of viral proteins. This segmented nature of the genome underlies the ability of influenza to mutate dramatically and cause pandemics, which is described in detail in Influenza 101.

The HA protein is particularly important. It is responsible for attachment of the virus to a target cell, and is also the protein against which our immune response produces protective antibodies. The structure of the HA protein also determines whether a virus is better suited to infecting avian or human cells, and therefore distinguishes between human and avian influenza viruses. When avian flu viruses do infect human cells, they normally do so deep in the respiratory tract, rather than in the upper respiratory tract. This makes them much less transmissible, or “contagious”, because they are less likely to be sneezed, coughed, or breathed out.

The Chinese researchers identified several troubling mutations in the HA protein of H7N9. Some of these mutations may make the virus better adapted to infecting human cells, especially cells in the upper respiratory tract. Other mutations are associated with an increased ability to infect cells outside the respiratory tract, and with increased virulence. Some of these mutations, as well as a mutations in a protein called PB2, are among those identified in last year’s controversial H5N1 research on avian flu transmission in ferrets. This underscores the critical important of continuing avian flu transmission research, despite the sensationalistic reporting in major media outlets such as The New York Times last year.

In the same issue of NEJM U.S. CDC flu researchers published a companion article detailing the pandemic risk posted by H7N9. The mutations identified by Chinese researchers make the risk very real. However, there is still no evidence of sustained person-to-person transmission, and little or no evidence for transmission even between very close contacts. The Chinese government is monitoring thousands of people who have been in contact with H7N9 patients, so any such transmission is likely to be quickly identified. Of course, the Chinese researchers as well as scientists in the U.S. and around the world are feverishly working to have a vaccine ready in the event H7N9 proves capable of causing a pandemic. Additionally, H7N9 is susceptible to Tamiflu, as demonstrated by the successful treatment of a young girl in Beijing along with laboratory testing.

Excellent resources for following new developments continue to be the CDC page on H7N9, the WHO disease outbreak and FAQ pages and the CDC Flu Twitter page. Additionally, feel free to leave comments or pose questions on our website or Facebook page.

-Steve

Saving Lives With Better Science Communication