Keeping tabs on TB

ALBUQUERQUE -- Dr. Gary Simpson, a self-described "infectious disease guy," says the recent disclosure that a government lab scientist might have been the source of deadly anthrax mailings post-9/11 brought to the forefront the need for national archives of infectious diseases, both bacterial and viral.

 

"It's just beyond me, to be honest [that it took six years]," Simpson told the New Mexico Independent. "[The anthrax] could have been from anywhere in the world." He said it could have come from Pakistan or from the naturally occurring anthrax in the soil in New Mexico, Louisiana and Texas.

 

But the source wasn't specifically pinpointed until this month "because we didn't have a national archive." If we had, he said, the result could have been known within weeks.

 

Creating a database for deadly pathogens has become a passion for Simpson, a molecular biologist and clinical associate research professor at the University of New Mexico, particularly when it comes to one of the world's greatest health threats -- tuberculosis.

 

He and distinguished colleagues in the field believe a TB archive of national and even international significance could be up and running -- serving scientists, clinicians and the public health community -- in just six months.

 

"It would be the nation's first integrated, comprehensive biological and informational resource," project director Dr. Damian Gessler told NMI. Gessler is a genome-sequencing expert with the National Center for Genome Resources, a private nonprofit in Santa Fe spun off from Los Alamos National Laboratory.

 

All that is lacking for the project's fruition is the funding: $15 million over three years -- "coffee money" in terms of health organizations and initiatives, in Simpson's words.

 

Pretty much everything else is already in place or easily accessible: the pathogen samples, the expertise, the support and the site -- not at Johns Hopkins, Cambridge or Stanford, but at UNM.

 

"With nothing more than today's technology, TB research could take a quantum leap into the information age," Simpson, Gessler and their colleagues wrote in a letter to potential supporters last year.

 

Ten of the leading science and health experts in the fight against tuberculosis, including Gessler, Simpson, UNM's Terry Yates and Paul Farmer, published in March 2006 a Policy Forum piece in Science magazine explaining the archive as a simple yet effective approach.

 

 

TB infects one-third of the world's population, with nearly 9 million new cases and up to 3 million deaths a year.

 

UNM is the ideal site for a National Tuberculosis Archive, supporters say, because it has already proven itself in the archiving field. In fact it was discussions Simpson had had with the late Terry Yates of UNM's Museum of Southwestern Biology that led to the kind of harmonic convergence that has brought the idea of a National Tuberculosis Archive in Albuquerque this far.

 

When people in the Southwest started dying from an unknown viral disease in 1993, Yates traced the cause to deer mice by testing a fraction of the 600,000-odd rodent specimens he had collected and placed in the museum. Simpson had met Yates just a few months before the mice were unequivocally documented as the cause of Hantavirus -- a mystery solved within days to weeks rather than months and years because of the museum, which was quite a feat considering the remote locations of those who came down with the disease.

 

"I had actually thought, what could that ever mean to me?" Simpson said of his discussions with Yates about the museum, which houses the second-largest specimen archive in the world, all genotyped and computerized by bar code. [A genotype is not an actual DNA sequence, but a kind of fingerprint that gives scientists an idea how strains may differ, Gessler explained.]

 

"The lesson I learned (from the Hantavirus case) is that we really need to able to tell where a pathogen strain is originating," Simpson said. "Is it from spill, an intentional release? Was it here all along and we didn't recognize it? Was it a non-pathological form and now it's dangerous, or is it newly introduced, like West Nile?"

 

Immense TB data already exists -- but not in one place

 

With tuberculosis, an immense collection of data is already in place. Gessler pointed out that most state health departments started as TB control departments, and actual sputum samples from patients have been collected by public health clinics for decades. The TB bacterium isolated from these samples and "grown" into living bacteria is accompanied by a form with all the information about the patient, whether the TB was pulmonary and whether it's drug-resistant. This bulky collection would be integrated at the archive at an anonymized level so that researchers and clinicians could determine down to the county where the TB was found without ever revealing a patient's name or address.

 

Gessler said that 15 years ago, it cost more than a $1 billion to sequence the human genome, whereas "you can now sequence 2 billion bases in three days for $10,000-$20,000."

 

Currently there are 13,000 strains of TB in the United States. "We could process 13,000 strains in a month!" Simpson said.

 

Dr. Marcos Burgos, New Mexico's medical director of TB control and an advocate of a national archive in Albuquerque, told NMI information from the archive could help researchers develop a new TB vaccine. "We are now at the point where the number of cases in the U.S. is slowly coming down," he said. "The question now is, what else can we do to improve TB control? The TB vaccine, basically developed in the 1920s, is 90 years old -- a very rudimentary vaccine" that doesn't help with pulmonary TB, which is TB's most common form.

 

"TB in other organs is not contagious, and if treated, one is never going to transmit it," said Burgos, an assistant professor in the Infectious Diseases Division at UNM Medical School's Department of Internal Medicine. Pulmonary TB, however, is airborne and contagious. "That's why we need a vaccine to treat TB as a whole."

 

New Mexico does not have the TB problem that is devastating other nations, particularly in Africa, Asia and some Central American countries. With a population of 2 million, New Mexico has 50 cases a year, Burgos said, whereas the south African nation of Lesoto, which also has a population of 2 million, has 40,000 cases a year.

 

The U.S. incidence rate is two to five per 100,000 people; the numbers are 25 to 40 per 100,000 in Mexico and 100 to 150 per 100,000 in Russia, he said.

 

 

As Gessler pointed out, nearly half the cases in the United States are in foreign-born residents who contracted the disease at a young age and are exhibiting symptoms now that they are older. An archive would help public health officials determine types of strains based on origin and how to best treat them.

 

 

Burgos said the archive could also help those doing research on bovine TB. He said there is little danger to humans from bovine TB in the United States because the bacterium is usually killed during the cooking process and usually found in the lungs -- "and we don't tend to eat lungs in the U.S." However, it is a problem in developing countries where they can't test their cattle, he said.

 

Simpson said he spent two days at a border conference earlier this month in Santa Teresa, where he heard that the United States is "importing 300,000 cattle a year from Chihuahua. They need a rapid test [for bovine TB]." The conference was also attended by representatives of the livestock industry, LANL, Sandia Laboratories and Homeland Security, he said.

 

New Mexico is perfect for the National TB Archive, Gessler said, because several groups are already involved and others have expressed an interest in participating: UNM would provide archiving; Los Alamos National Laboratory, research; National Center for Genome Resources, sequencing expertise; New Mexico Tech, cybersecurity; New Mexico State University, bovine TB research; and Tri-Core Laboratories, clinical expertise.

 

 

 

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