Dec 6, 2001 (CIDRAP News) Eighty-five million pieces of mail were processed at anthrax-contaminated Postal Service plants in New Jersey and Washington, DC, before the plants were closed, the Centers for Disease Control and Prevented (CDC) reported today. Although the numbers suggest that cross-contaminated mail may be widespread, officials said the risk of contracting inhalational anthrax from such mail is very low.
"The risk of contracting inhalational anthrax from cross-contaminated mail is very low, but it's not zero," CDC Director Jeffrey Koplan, MD, said in a telephone press briefing. He said that people who are concerned should take precautions in handling their mail, such as not opening suspicious-looking envelopes; avoiding sniffing, blowing on, or tearing envelopes; disposing of envelopes after opening; and washing hands afterward.
Koplan had said at a briefing Monday that "tens of thousands" of letters could have been cross-contaminated when processed at the postal facility in Hamilton Township, N.J., near Trenton, after anthrax-laced letters sent to US senators were processed there. In the Dec 7 issue of Morbidity and Mortality Weekly Report, published online today, the CDC reported that 85 million pieces of mail were processed at the Trenton facility and another in Washington, DC, after the plants were contaminated.
"Approximately 85 million pieces of mail were processed on the days after the implicated envelopes passed through the NJ and the District of Columbia (DC) sorting facilities until they were closed," the report states. "Both of these plants had widespread evidence of contamination with B[acillus] anthracis. Some of the pieces of mail that passed through these facilities could have been cross-contaminated and, in turn, could have contaminated mail processing equipment or other envelopes processed elsewhere."
However, the apparent absence of additional inhalational anthrax cases among 10.5 million people in New Jersey, Washington, Pennsylvania, Maryland, and Virginia since the initial cluster of cases suggests that the risk of contracting the disease from cross-contaminated mail is very low, the report says.
Koplan said that while the CDC believes the risk is very small, "We don't have all the answers. We're trying to balance protecting people from any illness, but without creating fear when it's unwarranted." At Monday's briefing, CDC officials had said that two of the recent cases of cutaneous anthrax were probably caused by cross-contamination.
In response to questions about the possibility of tracing mail that passed through the Trenton facility to identify recipients who might be at risk, Koplan said the mail was distributed so widely that such a project would be impractical. "If we had an exact set of locations of where all that mail goes, it would be simpler," he said. "Mail from that facility does go to a very wide distribution of places."
The MMWR report gives an update on the investigation of the case of Ottilie Lundgren, 94, of Oxford, Conn., who died of inhalational anthrax in November. Investigators have found no anthrax spores in Lundgren's immediate surroundings or in tests of her friends and relatives, nor have they found a direct link to any contaminated mail. But, as officials previously reported, anthrax spores were found in three high-speed mail sorters at a postal processing center in Wallingford, Conn., which serves Oxford and other nearby towns. In addition, spores were found on an envelope that was delivered to a home in Seymour, Conn., 4 miles from Lundgren's. That envelope had passed through the Trenton (N.J.) and Wallingford facilities.
Koplan said the CDC is still examining "a very large number of environmental samples" in the Lundgren case and is continuing to work with the Postal Service in a hunt for any links to contaminated mail. Prospective and retrospective disease surveillance has failed to reveal any other cases of anthrax in Connecticut, according to the MMWR report.
CDC officials also announced that the tally of recent cutaneous anthrax cases has dropped by one, from 12 to 11, with the determination that a Delaware man did not have the disease. The 54-year-old man, who worked at a New Jersey postal facility, had what was previously suspected to be cutaneous anthrax, but the case no longer meets the CDC case definition, the MMWR report says. A lesion on the man's hand and elevated antibody levels initially led to the suspicion of anthrax, but biopsies of the lesion did not reveal B anthracis and further antibody tests were negative.
As of Dec 5, the anthrax case count stood at 22, including 11 inhalational and 11 cutaneous cases, the CDC said. Only seven of the cutaneous cases were classified as confirmed.
In other comments at the press briefing, Koplan said it appears that Kathy Nguyen, the New York City woman who died of inhalational anthrax Oct 31, was 51 years old, not 61 as reported previously. Investigators have not found the source of the anthrax that infected her. Koplan said she took some antiarthritis medications, but there is no clinical evidence that she had a weak immune system.
CDC. Update: investigation of bioterrorism-related anthraxConnecticut, 2001. MMWR 2001(Dec 7):50(48):1077-9