Health Experts Call for Stockpiling Anti-Flu Drugs

18 March (Reuters Health [Stephanie Nebehay])— Health experts called for the creation of an international stockpile of life-saving antiviral drugs amid warning signs that a human influenza pandemic may be near.

The experts also called for efforts to explore regional or global production of vaccines, as manufacturers are concentrated in a few wealthy countries.

“A stockpile must be developed for a pandemic response,” said Teresa Tam, a specialist at Health Canada.

“There will not be enough time to generate more antivirals during a pandemic,” she told a news conference after 3-day talks at the World Health Organization (WHO) including experts from 40 countries.

The WHO has said antiviral drugs and vaccines would be in short supply in the early stages of a long-predicted flu pandemic, and the meeting was called to review global readiness for such a development.

Tam said many developing countries lacked antiviral supplies, adding that Vietnam reported having only 20 doses before the recent outbreak of bird flu.

Drug manufacturers are currently only producing what is required to combat annual seasonal flu outbreaks in the Northern and Southern Hemispheres, according to Tam and WHO officials.

There has been an average of 27.5 years between pandemics since 1883. The largest, in 1918–1919, killed 40 to 50 million people, with a mortality rate of 2.2%.

The last such pandemic was in 1968, although there have been 12 outbreaks with that potential since then. Klaus Stohr, head of WHO's global influenza program, said that only 36 of the organization's 192 members had pandemic combat plans.

Editor's comment. There are increasing numbers of reports of occurrence of avian influenza all over the world. With these outbreaks, there is always the potential danger of development of an influenza A strain that can spread easily from person to person and for which no immunity exists. A vaccine would not be available early in an outbreak, and a stockpile of antivirals sounds like an obvious solution. However, because of the cost of the drugs, the size of the stockpile that would be required, and the logistics of drug distribution, this is unlikely to occur on a worldwide basis. According to Craig R. Pringle, the ProMED-mail (http://www.promedmail.org) viral diseases moderator.

The major problem is that the precise antigenic type of any newly emerging pandemic influenzaAvirus cannot be predicted in advance. It is not practical to produce adequate stocks of vaccines against even a few of the possible combinations of haemagglutinin and neuraminidasetypes to which humans have no immunity. The best option would be to have one or a few well-resourced research laboratories able to provide a rapid response in an emergency, and a network of satellite laboratories to undertake the production of vaccine according to local needs. A wellorganized surveillance system would be an additional requirement.

Antivirals are expensive to produce and they are best used to ameliorate symptoms rather than prevent infection. They could play an important role by protecting health-care personnel and others in critical occupations.

Usda Says Mad Cow Testing Will Be Expanded

16 March (Reuters Health [Randy Fabi])—The United States plans to significantly boost its testing for mad cow disease to see whether the brain-wasting disease has taken hold in the US cattle population, the Agriculture Department (USDA) said on Monday [15 March].

USDA Chief Veterinarian Ron De- Haven told reporters the department wanted to test as many “high risk” cattle as possible.

The Bush administration has come under increased pressure from Congress, academic experts, and trading partners to expand its tests for mad cow disease after the first and only US case was discovered in Washington state in December.

USDA's announcement goes far beyond the government's original plan to test 40,000 of the 35 million cattle slaughtered this year.

The USDA said it aimed to test as many adult cattle as possible that are sick, unable to walk, or have died before slaughter. Some 446,000 cattle fall under this category annually.

Japan, the biggest buyer of American beef, has indicated it wanted the United States to test all of its slaughtered cattle for mad cow disease before easing its 3- month ban.

DeHaven said testing 201,000 cattle per year would allow inspectors to be at least 95% confident that if there was 1 case of mad cow disease among 10 million cattle, it could be identified. Testing 268,000 cattle would provide 99% confidence.

The USDA said it also will randomly sample cattle from 40 US slaughter plants that represent 86% of adult cattle.

The program is expected to be implemented by 1 June.

Editor's comment. Testing should be simplified by use of a test for bovine spongiform encephalopathy recently approved by the USDA. This test (from Bio- Rad) will determine within 4 h whether a cow was infected. The currently used test takes up to 5 days to yield a result.

Fda Approves Rapid Oral HIV Test

26 March (Reuters Health [Todd Zwillich])— Federal officials announced the approval of the first rapid oral test for HIV, which can give a result in as fast as 20 minutes.

The test, called OraQuick Rapid HIV- 1/2 Antibody Test, will be available initially in approximately 40,000 certified clinics and hospitals nationwide.

The test is identical to a rapid blood test that OraSure has marketed since November 2002. Friday's approval [i.e., on 26 March] clears the test for saliva testing.

To use the test, a subject wipes the inside of the mouth with a swab and then places the sample in a vial of reactant. After about 20 minutes, the test reveals the presence or absence of antibodies to HIV-1, the strain most often found in US patients.

Patients who test positive must have the results confirmed by a different HIV test.

Pertussis Outbreak At School Shows Disease Is Not Limited To Infants

18 March (Reuters Health)—In a report, the US Centers for Disease Control and Prevention (CDC) describe a recent pertussis outbreak that began at a middle school in Arizona and spread to surrounding communities.

Although pertussis rates are highest during infancy, the current report reinforces the idea that the disease can affect persons of any age. “Health-care providers should consider pertussis in persons of any age with acute cough illnesses and consider obtaining nasopharyngeal specimens for Bordetella pertussis culture,” the CDC states in its Morbidity and Mortality Weekly Report for 19 March.

The Arizona outbreak first surfaced on 21 September 2002, when pertussis in a 13-year-old student was reported to the Yavapai County Health Department. Later, officials realized that another student from the same classroom had presented 2 weeks earlier with symptoms consistent with pertussis. Soon after, several more students and teachers presented with prolonged cough illnesses consistent with the disease.

By 24 October, the outbreak had spread to 6 surrounding communities, leading local authorities to institute an accelerated pertussis vaccination schedule for infants. After peaking in mid-October, the outbreak gradually resolved, with the last culture- positive case involving a person with cough onset on 10 January 2003.

During the 6-month period, 485 pertussis cases were reported, 113 of which involved students, the CDC notes.

“Recognizing pertussis outbreaks in schools is challenging for several reasons, including (1) patients usually do not seek medical care early, (2) a diagnosis of pertussis might be delayed or not considered, and (3) the sensitivity and specificity of diagnostic tests will be low if [nasopharyngeal] specimens are not obtained and transported to the laboratory under optimal conditions,” the CDC concludes.

Source: MMWR Morb Mortal Wkly Rep CDC Surveill Summ 2004; 53:216–9.

Judge Rules Against Bayer on Poultry Antibiotic

17 March (Reuters Health [Lisa Richwine])— Drug maker Bayer lost an appeal of the US government's proposed ban of a poultry antibiotic that regulators partly blame for a rise in drug-resistant germs that infect people.

Bayer still has a chance to convince the Food and Drug Administration that the drug, Baytril, is an important therapy for treating sick chickens and should stay on the market.

The company is contesting an FDAproposal made in 2000 to outlaw Baytril, part of a family of potent antibiotics known as fluoroquinolones that doctors consider valuable for treating serious infections in people.

An FDA administrative law judge ruled in favor of the ban, FDA and Bayer officials said.

Health officials argue that widespread use of Baytril by livestock farmers is one reason more germs are becoming resistant to other fluoroquinolones.

Since the mid-1990s, when farmers started using fluoroquinolones to fight infections in poultry, researchers have seen the drugs become less powerful against Campylobacter.

Bayer plans to appeal the judge's decision to the FDA commissioner, who has the authority to make the final decision.

A coalition of consumer groups called Keep Antibiotics Working praised the judge's ruling and called on Bayer to voluntarily comply with the FDA's proposal.