Thoughts on the New Bird Flu H7N9 & It’s Animal Connection

3

Much of the United States is mesmerized by the belligerent squawks from North Korea’s Kim Jong-un and the volatile tension straddling the Korean peninsula, but I’m more concerned about what is happening in China right now and the troubling trickle of news on a new bird flu strain H7N9.

At least 16 people have been infected, patients who were widely distributed through the geographic enormity that is China, and already six have died. But what makes this small cluster of flu cases unusual is its timing – we usually see flu outbreaks emerging in the fall and winter months and we are just now breaking into the month of April – and that this type of flu strain is not known to infect humans.

H7N9 seems to be following a well established pattern of other emerging viruses: originating in east Asia, the infection appears to have a tentative association with wet markets and butchering, and is of zoonotic or animal origin. We’ve seen this situation previously with Nipah virus in Malaysia infected pigs and slaughterhouse employees and with SARS and its birth in the wet markets of Guangdong Province in China.

Laurie Garret masterfully crafts an unnerving story, of unknown unknowns regarding these human flu cases and the potential linkage between the thousands of pigs and fowl carcasses that clogged Chinese waterways in March.

Here’s how it would happen. Children playing along an urban river bank would spot hundreds of grotesque, bloated pig carcasses bobbing downstream. Hundreds of miles away, angry citizens would protest the rising stench from piles of dead ducks and swans, their rotting bodies collecting by the thousands along river banks. And three unrelated individuals would stagger into three different hospitals, gasping for air. Two would quickly die of severe pneumonia and the third would lay in critical condition in an intensive care unit for many days. Government officials would announce that a previously unknown virus had sickened three people, at least, and killed two of them. And while the world was left to wonder how the pigs, ducks, swans, and people might be connected, the World Health Organization would release deliberately terse statements, offering little insight.

By the end of March, at least 20,000 pig carcasses and tens of thousands of ducks and swans had washed upon riverbanks that stretch from the Lake Qinghai area all the way to the East China Sea — a distance roughly equivalent to the span between Miami and Boston. Nobody knows how many more thousands of birds and pigs have died, but gone uncounted as farmers buried or burned the carcasses to avoid reprimands from authorities.

We are very early into this developing scenario and this spate of cases could fizzle into just a blip in the news cycle and on the infectious disease radar. You should read Maryn McKenna’s reasoned and calm analysis here and to devour a slew of delicious infectious disease geek resources at the tail end of her article.

The point I want to make here is a reminder of how closely intertwined the lives of humans are with the lives of the animals we breed and eat. Not many of us raise pigs in the backyard or hear the cock’s crow in the morning and it’s easy to forget that for thousands of years we have lived in close proximity to our poultry and livestock.

But this is still the case in developing nations and particularly those with industries reliant on raising and butchering animals for the global market as well as people supporting a family with their hens and chicks. It is these people and places that are at most risk of emerging zoonotic infections like H7N9 and they require careful surveillance and monitoring of the health and well-being of both people and animals. Remember: catching a novel disease from an animal is the rule not the exception.

Resources

The most important link I can give you: “The New Bird Flu, And How To Read The News About It” from Maryn McKenna.

A timeline of events from Laurie Garret’s article “Is This a Pandemic?” in the short news cycle of H7N9. Her article can be accessed here.

Shanghai will be temporarily closing its live poultry markets on Saturday due to fears of a spreading H7N9 .

Meet Your Mites

3

Just two months ago, I had the distinct pleasure of acting not as a science scholar but as a research participant. Instead of having my face in a book, I willingly offered it to a woman who diligently scraped my forehead in search of Demodex mites. I know that it’s everyone’s humble dream to contribute their own exquisite arachnological flora to Science with an S and so, yes Reader, I can feel your oozing envy.

I spent the last weekend of January in Raleigh, North Carolina attending the incredible Science Online 2013 conference and one of the events at the opening reception included an opportunity to “Meet Your Mites” from the Your Wild Life team. As you can imagine, I quite literally squealed for joy. Demodex is one of my favorite parasites and I was eager to contribute my own special brand of commensal to a subject that is little studied. While waiting impatiently in line, my fellow participants and I gazed at a video of a squirming captive mite recently scraped with spatula from a very lucky individual and excitedly wondered if we too would see our own Demodex under the microscope.

You can see a Youtube video below of a mite that yielded to the executioner’s spatula from the Science Online event below!

Your Wild Life is a “team of scientists, science communicators, students, and citizens who are passionate about exploring the ecological frontiers that exist right under our noses.” Thus far they’ve ventured into some amazing, uncharted territory – looking at the bacterial biodiversity of belly buttons and armpits, the spectrum of arthropod species in human households, among other fact-finding missions that seek to illuminate the underlying richness that lives within and around us.

Meet Your Mites is their very latest biological mission on this little known buggie. In fact, the most that we know of Demodex mites is that … well, that they can be found on people’s faces. We don’t know much of anything about their evolutionary history, their geographical distribution and prevalence, or their preference for cosmetics. Just what are these little guys (and girls) up to? Why are they nesting in our eyebrows, crawling over our eyelids and eating our sebaceous goo? What kind of awful cosmological practical joke is this?

Megan Thoemmes is a research assistant affiliated with the this endeavour and she kindly enlightened me on this very fun project.

What is the goal of the Meet Your Mites project? 

The purpose of this study is to map the evolutionary history of Demodex mites with the expansion of human populations through time and space. Despite their intimate, parasitic relationship with human hosts, Demodex mites have not been extensively studied. We will trace the evolutionary history and  diversification of Demodex mites, and in doing so, gain new insights about the radiation of human populations.

Why now? 

This is the age of personal science, where we are learning about the similarities and differences between people and their own individual biomes. Understanding our association with these organisms is an important piece of the picture when figuring out the relationships we have with the species that live on, in and around our bodies. This project also serves as an opportunity to reach out and engage the public in both interesting and significant research. What have you guys found so far?

The project is still in its infancy, so we don’t have a large sample size or any solid results yet. We have just had our first round of sampling events, and we are trying to figure out our methods for getting the best possible DNA sequences from the mites, but we do seem to have a good method for sample collection. We’re also working out a new way of getting mite DNA from an individual’s face that would allow the participant to easily sample themselves, while allowing us to get a large number of samples from around the world.
Even though we are still in the early stages of the project, I suppose that one of the most interesting observations we have had is that there is a lot of morphological variation across the individual mites, and we think it is possible we could be seeing more than the two previously described species of human specific mites. 
A captured Demodex brevis,  a rare species that the Meet Your Mites has only found with certainty twice. Image: Your Wild Life.

Under the microcope, a captured Demodex brevis, one of two species of Demodex mites found on humans. Image: Your Wild Life.

The Meet Your Mites project hopes to shed light on the ancient history of one of our most ancient and overlooked commensals. I’m eager to hear what they discover and to see if one of my own little mite sidekicks has yielded any of my precious bodily secrets. And if you’re in the Raleigh-Durham area, you can contribute to this form of citizen-science too, as the project is hosting various “face sampling events” over the year. You can sign up here to be notified of upcoming events and check out their website on the project here. Face sampling, ya’ll, face sampling! How can you resist?

Resources
Visit the Your Wild Life website to learn more about their fun projects, the resarch team and read their blog.
Dr. Rob Dunn heads the Your Wild Life project with Dr. Holly Menninger and has written a book on the subject of our commensal comrades. You can purchase his book here and visit his website here.

A Nepalese Odysseus: XDR-TB is in South Texas

The Wall Street Journal has a superb write-up of a Nepalese man infected with extremely drug resistant tuberculosis (XDR-TB) who is currently detained at the US border in South Texas. XDR-TB is resistant to four of the major types of antibiotics that are used to treat and control TB infections and this man is the first person with this particularly dangerous strain of TB  to cross the border and be quarantined in this country (1).

Traveling in all of the modern ways known to man – by foot, car, boat and plane – the man ventured from his home in Nepal, traipsing through South Asia, flying to Brazil and hoofing it through Central America until reaching the southernmost tip of Texas.

From the WSJ,

His three-month odyssey through 13 countries – from his homeland of Nepal through South Asia, Brazil, Mexico, and finally into Texas – shows the way in which dangerous new strains of the disease can migrate across the world unchecked.

The Nepalese patient was taken into custody by the U.S. Border Patrol in late November as he tried to cross the border illegally near McAllen, Texas, according to Department of Homeland Security officials. The government declined to name him. He was transferred five days later to an Immigration and Customs Enforcement detention facility in Los Fresnos, Texas, and put into “medical isolation” with suspected tuberculosis.

 His XDR strain has been seen only once before in the U.S., in another patient of Nepalese origin, according to the government description.

A map of the U.S. Quarantine Stations. Staffed with quarantine medical and public health officers from CDC, they're located at 20 ports of entry and land-border crossings where international travelers arrive. Image: CDC. Click for source.

A map of the U.S. Quarantine Stations. Staffed with quarantine medical and public health officers from CDC, they’re located at 20 ports of entry and land-border crossings where international travelers arrive. Image: CDC. Click for source.

Our Nepalese man has innocently launched a global public health dilemma: of the potentially thousands of people that this man came across in his odyssey, who else has he infected? It will be a herculean and futile task for public health officers as many of the people that he may have passed on this pathogen are in a similar socioeconomic, nomadic situation – fellow tenacious migrants that quickly move from one place to another in their journey for economic sanctuary and personal salvation.

This case is a powerful reminder that globalization and innovations in travel have radically changed the rules of the game for dangerous and communicable infectious diseases. Of the 950,000 international travelers that arrive in the United States every single day, good public health institutions like the US quarantine stations scattered throughout the country are vital to monitoring hitch-hiking drug-resistant pathogens (2).

Please click here to read the WSJ’s article “Dangerous TB Patient Detained on U.S. Border.”

Note: To be specific, XDR-TB is resistant to the two first-line drugs, isoniazid and rifampin, used to treat TB initially, plus any fluoroquinolone and at least one of three injectable second-line drugs (i.e., amikacin, kanamycin, or capreomycin).

Resources

A fact sheet from the CDC on XDR-TB.

Reference

(1) B McKay (March 1, 2013) Dangerous TB Patient Detained on U.S. Border. Wall Street Journal. Accessed on March 7, 2013 here.

(2) CDC (August 3, 2012) Public Health Interventions Involving Travelers with Tuberculosis — U.S. Ports of Entry, 2007–2012. MMWR. 61(30); 570-573.

ResearchBlogging.org
Centers for Disease Control and Prevention (CDC) (2012). Public health interventions involving travelers with tuberculosis–U.S. ports of entry, 2007-2012. MMWR. Morbidity and mortality weekly report, 61 (30), 570-3 PMID: 22854625