Biothreat projections for pandemic and bioterrorist planning are generated by a straight-forward computational system, rather than scientific evidence. The mathematical-modeling method typically uses three variables involved in disease transmission with values culled from assorted past epidemics, often assuming the absolute worst-case scenario. However, other important metrics, such as biological plausibility, relevant historical data, and modern medical practice, are often ignored. Past pandemic projections for avian flu, smallpox, anthrax, swine flu, and Ebola grotesquely overestimated the disease's incidence and mortality illustrating deficiencies in current models, and in some cases, generating adverse health consequences more severe than any realistic epidemic. These catastrophic predictions generate fear and hysteria, thereby establish the predicate for maximum federal funding, impeding rational safeguards to our national security by inappropriately diverting resources from necessary, but less glamorous, quotidian public-health concerns. Rather than modeling actual weapons of mass destruction, in essence, the exercise artificially creates weapons of mass hysteria ("WMH").
Allocating billions of dollars to futile biodefense endeavors--or WMH--is clearly wasteful. It also breeds suspicion about the government's ability to accurately predict and prepare for biothreats, damaging citizens' confidence in governmental anti-terrorism programs and in homeland-security preparedness. Consistently overestimating epidemic risks suggests a systemic failure in methodology, highlighting the need for a scientific-statecraft paradigm to properly assess these risks.
For fear of being underprepared, the government continues to rely on worst-case scenario models. Trying to prove these models are flawed is fraught with political danger. What if these worst-case scenarios are in fact correct? Ignoring the possibility of calamity is a consideration no politician wishes to contemplate, even if overzealous projections ultimately cause more harm than more realistic and more prudent risk estimates.
This article demonstrates that worst-case scenario mathematical models for projection purposes are invalid, dangerous, and possibly motivated by their proponents' personal interests by using past smallpox epidemics as a case-study. Further, this work discusses historical facts that seriously undermine the assumptions used in homeland-security planning for smallpox and raises considerations that may be useful in planning for other biothreats.
"It is the beginning of scientific wisdom to recognize that not all questions have answers." ([dagger][dagger])
Contents I. Introduction II. Background III. Are Models Beautiful? A. Re-Analysis of Mathematical Modeling of Disease Projections B. Re-Modeling Dark Winter (DW) C. Parameters for Evaluating Disease Transmission 1. Exposure and Attack Rate 2. Reproduction Rate and the Transmission Rate 3. Transmission Potential and Susceptibility 4. Generations of Transmission and Case-Fatality Rate 5. Extrinsic Factors and Secular Trends IV. Truth? or Consequences A. A Statistical Summary of Post-World War II Epidemics B. Research Plan and Methodology C. Factors of Concern V. The Case-Studies A. New York City in 1947: The Vaccine-Shortage Scenario B. Bradford, England, in 1961-62: High Case-Fatality Rate C. Canada in 1962: Limited Transnational Transmission D. Stockholm in 1963: Spread by Close Contact E. Germany in 1970: Airborne Transmission(?) F. Yugoslavia in 1972: Instant Access to Eighteen Million Doses of Vaccine... G. 1973 and 1978: Laboratory Outbreaks VI. Analysis A. Modeling Revisited B. Replication Rate C. Delay in Diagnosis D. Infectivity and Spread E. Susceptibility F. Case-Fatality Rates G. Spread by Air Travel H. Airborne or Weaponized Transmission J. Hype, Hyperbole, Hysteria, and the Press J. Vaccine Availability K. Vaccine Hysteria a. Would inadequate vaccine engender hysteria as Dark Winter predicts? b. Was an approach other than mass vaccination available? c. Could the United States have gotten more vaccine sooner? d. Is vaccine dilution feasible? L. Who makes decisions on the data to use? Conclusion Appendix I. Introduction
After the 2001 and 2002 anthrax scares, official American bio-terror priority lists were updated. (1) The Centers for Disease Control and Prevention ("CDC") in Atlanta, Georgia had refined its original list of high-profile bio-agents based on the conclusions of Donald Henderson and his Working Group on Civilian Biodefense, (2) put forth in 1999. (3) The group identified six agents as particularly fearsome, and prominently featured smallpox as the worst of the Class A bioterrorist agents. (4) By 2001 the CDC dramatically augmented the list. (5) Among the new diseases listed was Ebola, now also considered a Class A bioterrorist threat due to its perceived high case-fatality rate, (6) ease of spread, and contagion. (7)
To deal with the expected biothreats, states enacted myriad quarantine regulations, (8) academic institutions composed manuals for disaster planning, (9) public-health lawyers drafted model laws, (10) government agencies developed contingency plans, (11) Presidents Bush and Obama signed key Executive Orders, (12) and millions of dollars were allocated to academia to develop homeland-security programs. (13) In 2005, the CDC proposed a regulation authorizing it to impound planes or ships with passengers who appeared ill with summary provisions allowing for up to a week's detention. (14) The regulation never passed, but the sentiment of the country was clear: better to restrict travel for anyone who might transmit a contagious disease than for a single American to succumb to one. (15) By 2007, the United States operated more than 1356 level-three biosafety labs and fifteen level-four biosafety labs, (16) presumably to devise treatment and preventive measures for bioterrorist and pandemic threats. To date, the results of their research are murky at best.
It appears, however, that the bioterror-prevention tactics were for naught. In the ensuing decade, no bioterrorist-mediated event materialized and none appear on the event-horizon. Mother Nature, however, filled the gap. In 2014, she unleashed an epidemic of unseen proportions in recent times: the Ebola virus swept through Africa. In March, the World Health Organization ("WHO") reported its outbreak in four districts of Guinea with eighty-six suspected cases and fifty-nine deaths. (17) More cases were reported in neighboring Liberia and Sierra Leone. (18) Not long afterwards, Liberia declared an international state of emergency, (19) generating fear that cascaded out of control; apocalyptic projections predicted 1.4 million cases by January, 2015. (20) The WHO re-sounded the pandemic warning on August 8, 2014, (21) allocating billions of dollars and deploying thousands of personnel to infection zones as top-tier health officials around the world made potentially risky decisions. (22)
The United States mounted an unprecedented response effort in terms of funding, allocation of person-power, and deployment of healthcare workers and auxiliary personnel. A White House press release announced that the U.S. would be "leveraging] the unique capabilities of the U.S. military and broader uniformed services to help bring the epidemic under control," (23) which "would entail command and control, logistics expertise, training, engineering support and 350 million dollars." (24) The WHO allocated more aid in October, (25) after the CDC published its September Mortality and Morbidity Report ("MMWR") that estimated approximately eight-thousand cases would occur in Liberia and Sierra Leone by September 30, noting the figure could be 21,000 when correcting for underreporting. (26) To account for underreporting, the MMWR used a correction factor of 2.5, asserting that "for every case reported and recorded in publicly available case counts, an additional 1.5 cases are not recorded." (27) The CDC concluded that "without additional interventions or changes in community behavior ... by January 20, 2015, there will be a total of approximately ... 1.4 million [cases]." (28) The CDC used a ninety percent case-fatality rate estimate for the Zaire subtype of Ebola and predicted there would be 1.26 million deaths; (29) the WHO used an estimated case-fatality rate of seventy percent, and predicted approximately one million deaths. (30)
More than a year later, after WHO declared the epidemic over, a grand total of 28,638 cases and 11,315 deaths were reported worldwide. (31) Of these fatalities, eighty-seven percent were in Liberia and Sierra Leone. (32) The worldwide case-fatality rate did not even reach forty percent; in Liberia and Sierra Leone, it barely topped thirty-five percent, similar to the case-fatality rates for hantavirus and Legionnaires' disease. (33)
The press and public-health experts criticized WHO for its inadequate response efforts, (34) yet the projection-versus-reality mismatch and resultant hysteria was never addressed. It appears that the CDC's and WHO's estimation methodologies were flawed due to a lack of critical information and rapidly changing parameters on the ground. (35) Had this been the only incident of gross over-projection, one might attribute the mishap to an anomaly. However, the consistent pattern of over-projection calls into question the efficacy of mathematical modeling as a pandemic-projection tool. We saw similar overestimates for swine flu, (36) avian flu, (37) anthrax, and Middle East Respiratory Syndrome ("MERS"). (38) An all-but-certain and omnipresent bioterrorist-attack clarion call emerged:
[a]s the 20th century drew to a close, most biological[-]defense professionals, both military and civilian, were in agreement that the probability of a bioterrorist event occurring the United States was not a matter of if, but when....'if' is now behind us, and we are left...