The top 10 infectious disease news stories in 2001

December 2001

As regular readers know, the December issue of Infectious Disease News has become a time of reflection and looking back over the year past. This year, again, we offer the selection of top 10 infectious disease stories published during the year, as selected by members of the editorial board. We would not presume to rank-order them, so in no particular order, here they are:

• Vaccine-associated polio outbreak in Haiti
• Keeping out BSE and vCJD
• Ebola virus outbreak in Uganda finally contained
• IOM Committee finds no link between MMR vaccine and autism
• Evidence against a relationship between hepatitis B vaccine and MS
• Developing linezolid resistance
• Spreading viruses: dengue, hantavirus, West Nile virus
• Bioterrorism
• Hepatitis G may improve HIV survival rates
• EIS is 50 years old

Several of these topics have appeared on our “top 10” list in prior years; others are brand new. The updated stories appear in a special section of this issue. Some comments follow about these stories, as well as some that do NOT appear on the list.

Bioterrorism stands out as the most shocking story of the year. The anthrax outbreak appears finally to be subsiding, and a great deal of new information has been gleaned already. Notable is the relatively low (40%) mortality rate among the first 10 cases of inhalational anthrax, and the inference that modern hospital care and antibiotic therapy can reduce the mortality rate in this disease, previously documented to be >80%. Also notable is the stunning efficiency of spore distribution within the U.S. mail system.

Of greatest concern is the fact that we are just as susceptible to this kind of terrorist event today as we were 2 months ago! Attention is turning to other infectious agents that might pose a threat, most notably smallpox. The “surveillance and ring vaccination” approach to global smallpox eradication, used with striking success in developing countries 3 decades ago, was announced by CDC as its initial plan for containing smallpox, should there be such an event in the United States. Whether this approach would work as well in a highly mobile society such as ours as it worked in relatively immobile populations in the developing world 30 years ago is not known. One hopes that this question will never need to be answered.

The EIS 50th anniversary story is surely closely linked to the previous story, for CDC has been very much in the center of the investigation. (It probably also reflects the fact that a number of editorial board members are EIS alumni!) Ironically, one of Alex Langmuir’s major justifications for initiating the Epidemic Intelligence Service was to enhance preparedness for biowarfare, a great concern as the Cold War evolved after WWII; 50 years elapsed before this capability was needed. Critics are already examining CDC’s performance in the anthrax “event,” and while there were some missteps, to be sure, and a lot of mid-course learning and correcting, CDC in general acquitted itself well.

Emerging infections in 2001

Several stories deal with “emerging” or spreading viruses. The largest reported outbreak of Ebola hemorrhagic fever was finally contained in Uganda, after continuing for 6 months or more, and involving 425 patients and 224 deaths. The second story deals with the spread of arbovirus infections to new locations, dengue to Hawaii, hantavirus infection to New England, and West Nile virus down the East Coast to Florida and Georgia. Such virus spread undoubtedly will continue, and surprise us even more as the population grows and as the virus and vectors adapt to new environments. Fortunately, none of these viruses (except possibly Ebola) show any propensity for person-to person spread via the respiratory route.

The outbreak of OPV-derived type 1 polio is worrisome, of course, and vividly illustrates what can happen when populations are incompletely or inadequately immunized and when OPV continues to be used. This outbreak is a strong argument for immunizing the entire population at risk and maintaining a high level of immunity; of course, it can also be an argument for switching to IPV.

Two other stories represent vaccine science with negative results, ie, the conclusion of an IOM committee that there was no link between MMR vaccine (M-M-R II, Merck) and the development of autism, and the other reporting two investigations published in The New England Journal of Medicine that could identify no link between hepatitis B vaccine and demyelinating diseases such as multiple sclerosis. The MMR–autism link has gained a following in England, and the hepatitis B vaccine/MS link spread in France. Although it is certainly beneficial to have such negative data available, the sad truth is that many of the vaccine “dissidents” simply do not accept scientific evidence as “truth,” and will never believe that there was any other cause for their own or their loved one’s condition, however persuasive the evidence might be.

Bovine spongiform encephalopathy is an old-timer on this list. The top 10 “tradition” is really only 5 years old and was first done in 1996; BSE was on that list, too. Although there were no startling new scientific developments, the topic remains of great concern because of the continuing spread of BSE to countries in which it has not previously been identified, ie, Japan, and because of the continuing importation of possibly contaminated animal protein and by-products into this country. A page 1 story in the Wall Street Journal on Nov. 28, 2001, detailed just how porous our borders are, and did not make reassuring reading. A blood/serum/urine test to detect BSE-infected cattle remains the “holy grail” for this disease for the present.

Linezolid resistance came as no surprise, but the speed with which it appeared did provide a surprise, and an unpleasant one. Risk factors facilitating the appearance of resistance are well known by now, but are reinforced by this report; they include the presence of an indwelling prosthetic device, long-term therapy, suboptimal dosing, and of greatest importance, undrained pus.

The only AIDS/HIV story on the list (surprising in itself) is a very tantalizing one, that is, the apparent protection against lethality conferred by co-infection with both hepatitis G (GBV-C) and HIV. Further studies of this phenomenon will surely enhance our understanding of the immunopathogenesis of HIV infection, and possibly provide important clues about new targets for drug/vaccine development.

One worth mentioning

Finally, one story not on the list that merits brief comment is the report of the field trial and now the licensure of recombinant activated protein C (drotrecogin a) for severe sepsis. The sponsor, Eli Lilly, has mounted an extensive promotional effort to introduce this product. It seems to have attracted little interest within the ID community, probably reflecting the fact that most ID physicians do not function as critical care physicians, with a few exceptions. The product clearly brings about a modest ( ±20%) but real reduction in mortality from severe sepsis. I believe this is noteworthy for 3 reasons. First is that it represents the first success for recombinant immune modulators after a series of 5-6 strikeouts in the past. Second, even if not a home run, it is at least a solid single. And finally, other recombinant products are being developed that work at a number of different sites in the inflammatory cascade, and may prove even more effective, perhaps in combination, in treating the systemic inflammatory response syndrome.