Transmission of Smallpox: Systemic Review of Natural Outbreaks in Europe & North America Since Wwii

It is a deadly virus that can kill as many as 30% of the people it infects. As recently at 1967, an estimated 15 million people contracted the disease, with 2 million of those dying. What is this sickness? Smallpox, caused by the Variola virus, is a highly contagious disease that, if unprepared for, could cause mass devastation if used as a biological weapon. Its affects can range from small, raised pustules on the skin combined with flu-like symptoms, to hemorrhages that develop in the skin and mucous membranes that can cause the skin to slough off. A disease this virulent must be prepared for. In this post-9/11 era, readiness is as important as ever, and one of the most efficient ways to be prepared for a smallpox attack is to study its transmission patterns in Europe and North America following World War II, specifically examining our current vulnerability, traits of these past outbreaks, and any patterns that may arise.

So why is smallpox such a threat to today's society? Though it was eradicated in 1977, the virus is still stored officially in two licensed labs in the United States and Russia (Radetsky, 1999; Outbreak, 2004). Additionally, there exists a very real worry that terrorists have acquired weaponized forms of the disease, and a definite concern that the virus can be mass produced (Henderson et al, 1999). These weapons could include an aerosol form, where virus particles are dispersed in the air, resulting in a widespread distribution that would affect many people (Smallpox FAQ, 2005; Henderson et al, 1999). Once let out, the virus can survive for more that twenty-four hours if the location of release if not decontaminated by ultraviolet light (Henderson et al, 1999). Due to the fact that an infectious measure of the virus is very small, a delivery device could easily be smuggled into a busy location. Furthermore, those who do not contract the disease may panic even if a small outbreak occurs. That is because when a person hears "smallpox," they think of a horrible disease which they do not understand. The panic would perhaps require law enforcement officials to use their resources not only in conjunction with containment measures, but also to control the general public. If another, more conventional attack were to then occur, it would be pure pandemonium. It is extremely likely, though, that the present society would be devastated by a release of smallpox, even if no other attack was combined with it. While vaccination in the United States was standard three decades ago, it has since come to an end, leaving the population without any resistance, even for those who were vaccinated because the effects fade over time (Henderson et al, 1999). Furthermore, there are certain groups of people who should not receive the vaccine, including pregnant women and people with eczema (Henderson et al, 1999). Heightening that existing weakness is the mobility of our culture, which, when combined with an already severely contagious disease, could be catastrophic (Henderson et al, 1999). The virus could move around the country as fast as its human hosts can, allowing it to spread at a heightened pace in several parts of the country, or even the world. Europe and North America after 1945 best represent the modern United States as a pre-eradication era "in terms of their demographic, social, and physical structure" (Bhatnagar et al, 2006). During this time, few adults were re-vaccinated, and because outbreaks were rare, there was little chance for naturally attained protection (Bhatnagar et al, 2006).

These conditions make the post-World War II era most suitable for an analysis of the United States' current susceptibility. From 1945 until the disease's eradication, there were a total of fifty-one significant outbreaks that were documented, with forty-five of those having enough pertinent information to be analyzed thoroughly. The following pieces of information had to be included in the records for the outbreak to be part of the review: "the date of occurrence, and the number of index cases, total cases, cases in each generation, and generations" (Bhatnagar et al, 2006). These features can assist in evaluating the effect of an outbreak, along with the effective reproductive rate (R), which is how many people some one with the virus could infect in a realistic setting (Bhatnagar et al, 2006). In this study, R was equal to the number of first generation cases, which are those that are contracted from original, or index, cases, divided by the index cases (Bhatnagar et al, 2006). Additional information was also considered, including "the number of cases acquired within a hospital, a household, or at a distance...the number of missed cases...and deaths; the generation at which the outbreak was identified, and the clinical presentation of the index case" (Bhatnagar et al, 2006). Lastly, whether ring vaccination, case isolation, quarantine, and/or mass vaccination were used was also noted (Bhatnagar et al, 2006). As for where the outbreaks are seen to have occurred, the greater part of them took place in the following three countries: eighteen in the United Kingdom (40%), eight in the Federal Republic of Germany (18%), and three in the U.S.S.R. (7%) (Bhatnagar et al, 2006). Four of the aforementioned forty-five outbreaks have been separated and divided into ten separate outbreaks by V. Bhatnagar and his associates, bringing the total back to fifty-one. The R value for all of these cases had a median value of two in a range of zero to thirty-eight (Bhatnagar et al, 2006). Over 66% of the outbreaks never surpassed an R of 3, with half having it equal to one or less (Bhatnagar et al, 2006). Though there existed as many as nine generations in a single outbreak, close to "a third did not extend beyond the index generation, and nearly three quarters lasted for 3 or fewer generations," (Bhatnagar et al, 2006). The number of deaths covered a broad spectrum, as well, maxing out at twenty-six for an outbreak in Yugoslavia, with some cases having no deaths at all (Bhatnagar et al, 2006). However, as with previous details of the incidents, the majority of occurrences were in the lower region of the range, as evident by the fact that 75% had three or fewer deaths (Bhatnagar et al, 2006).

Many of these characteristics of the outbreaks follow certain trends that are consistent throughout all incidences. For example, the outbreaks that had high R values were inclined to also last longer and cause more cases of the disease (Bhatnagar et al, 2006). There were also thirty cases that were described in greater detail, and these had more deaths, total cases, generations, and higher R values than the twenty-one with fewer factors involved (Bhatnagar et al, 2006). The fact that they were larger in scale may be why more details were available. At the time of the documentation of the outbreaks, smallpox was still fairly