WASHINGTON - More than 14 million people worldwide are affected by tuberculosis, the National Institutes of Health (NIH) said, marking the anniversary Monday of World TB Day.
Nearly one-third of the world's population is infected with Mycobacterium tuberculosis, the bacterium that causes TB, according to the NIH. While the disease is on the rise worldwide, it is on the decline in the U.S., with 13,293 cases reported in 2007, a drop of 4.2 percent from 2006, health officials reported. Foreign-born residents and racial and ethnic minorities accounted for a majority of the U.S. cases.
The TB incidence rate in the U.S. for 2007 was the lowest recorded since national reporting began in 1953, the Centers for Disease Control and Prevention reported.
However, despite the overall improvement in the U.S., progress in eradicating the disease here has slowed in recent years.
The average annual percentage decline in the TB rate slowed from 7.3 percent per year from 1993 to 2000 to 3.8 percent during 2000 to 2007, the CDC said.
The TB rate in foreign-born U.S. residents was nearly 10 times higher than that of those born in this country, health officials said. Among U.S.-born racial and ethnic groups, the greatest disparity in TB rates was for U.S.-born blacks, whose rate remained nearly eight times that of whites.
The slowing decline in TB incidence and the persistent disparities among foreign-born residents and minorities threaten progress toward TB elimination in the U.S., the CDC declared.
Among new cases of TB, about 5 percent, or 500,000 annually, are multidrug-resistant, with resistance to at least the first-line TB drugs isoniazid and rifampin, NIH officials said.
The proportion of multidrug-resistant TB cases in the U.S. remained stable in 2006, accounting for 1.1 percent of cases for which data are available, the CDC said.
Controlling TB ultimately depends on effective prevention strategies, such as new vaccines, NIH officials said, noting that the agency considers development of TB vaccines a top priority.
NIH officials noted that Rockville, Md.-based Sequella Inc. recently was granted orphan-drug status by the FDA and the European Medicines Agency for its anti-TB drug candidate SQ109, which the firm developed in partnership with the NIH's National Institute of Allergy and Infectious Diseases.
SQ109 has demonstrated in vitro and in vivo activity against drug-susceptible and drug-resistant TB bacterium and has shown an ability to synergize with other TB drugs in experimental animal models, according to Sequella.
The current market for TB drugs and vaccines is estimated to be about $450 million and is projected to reach $700 million by 2010, according to the Global Alliance for TB Drug Development.
Congress to Probe Heparin Safety Issue
Reps. Bart Stupak (D-Mich.), chairman of the House Energy and Commerce Subcommittee on Oversight and Investigations, and ranking member John Shimkus (R-Ill.) said they plan to convene at least two hearings next month to examine the latest U.S. drug safety crisis, which involved tainted heparin and a Chinese manufacturing site.
After a month of investigating the cause of hundreds of heparin-associated allergic-type reactions, which caused at least 19 confirmed deaths, the FDA said it had identified a contaminant in batches of the drug as oversulfated chondroitin sulfate, a synthetic chemical substance.
The active ingredient in heparin is derived from pig intestines.
The chemical contaminant, which mimics heparin activity "didn't come straight from the pig," Janet Woodcock, director of the FDA's Center for Drug Evaluation and Research, told reporters.
Woodcock added that it is unclear at this point in the FDA's investigation whether the contaminant was added to the batches of heparin deliberately or accidentally.
A congressional investigation found that the Chinese facility where the active pharmaceutical ingredient for Baxter International Inc.'s heparin was made had never been inspected by the FDA.
Stupak, along with Rep. John Dingell (D-Mich.), chairman of the Energy and Commerce Committee, are considering emergency legislation to force the FDA to conduct pre-approval inspections. (See BioWorld Today, Feb. 25, 2008.)
The lawmakers have asked FDA Commissioner Andrew von Eschenbach to provide information to the subcommittee about policies and procedures in conducting inspections of plants in China.
The FDA each year inspects 20 percent or less of the 700 Chinese manufacturing facilities where U.S. drugs are made, congressional investigators have found.
"At this inspection rate, FDA can only inspect a Chinese firm exporting drug products to the U.S. once every 40 to 50 years," lawmakers said in a March 19 letter to von Eschenbach.
The FDA last week said it planned to place eight new safety inspectors in China and hire five Chinese nationals to work at diplomatic posts in that nation to improve the safety of products exported to the U.S. (See BioWorld Today, March 18, 2008.)
The heparin safety issue, Dingell said in a statement, "underscores our concerns that FDA does not have a robust enough presence overseas in conducting inspections in plants that make drugs for the U.S. market. Ongoing surveillance inspections are critical if FDA is to find shortcomings."
Rep. Joe Barton (R-Texas), ranking member of the Energy and Commerce Committee, said the contaminated heparin "only heightens my suspicions about deliberate illegal conduct and reinforces my concerns about the need for closely examining Chinese manufacturers that ship FDA-regulated products to the United States."
Stupak said the hearings, scheduled tentatively for April 15 and 22, will evaluate what went wrong leading up to the heparin recall and the role increased overseas inspections by the FDA could play in preventing future incidents.
In addition, lawmakers want von Eschenbach to explain how to address the subcommittee's concerns about the FDA efforts to inspect foreign drug plants making products for the U.S. market.