15.9: Conflicting ethics

Fundamental conflicts in ethical behavior are hidden just below the surface of the cold mathematics in these equations. Virulence \(\alpha\) appearing in the numerator of a term with a minus sign means that the greater the virulence, the lower the equilibrium level of disease, \(\hat{p}\). In the absence of vaccination \((v\,=\,0)\), setting \(\hat{p}\) = 0 and solving for \(\alpha\) yields \(\alpha\,=\,\beta\). Artificially increasing the virulence \(\alpha\) of a disease to equal or exceed the infectivity \(\beta\) will therefore drive the disease extinct.

The enduring ethical conflict here is between the individual and the population. With all other things being equal, working to reduce virulence benefits the individual but may cause more individuals in the population to become infected. Working to increase virulence, in contrast, harms individuals but may reduce the number who become infected.

The ethics of modern medicine emphasizes individuals— working to cure disease and reduce virulence, ameliorating symptoms, reducing discomfort, and recognizing patient needs. Increasing the virulence of a disease in a human patient to reduce its spread is unthinkable, both in medicine and public health. The ethics of modern agriculture, however, are the diametric opposite. If a crop is infected with a destructive communicable disease, entire fields of the crop may be mowed, burned, or otherwise disposed of. Infected populations of poultry and livestock are treated similarly, killed en masse and buried or burned to contain the disease.

Artificially altering the infectivity \(\beta\) is also a possibility. In Equation 15.4, \(\beta\) appears in the denominator of a term having a minus sign—meaning that decreasing \(\beta\) will decrease the equilibrium level of the disease, \(\hat{p}\). Ethical conflicts also arise here, though they are not as stark as the conflicts connected with \(\alpha\). During the influenza epidemic of 1918–19, San Francisco leaders required citizens to wear breathing masks—for “conscience, patriotism, and self-protection,” wrote the mayor.

Figure \(\PageIndex{1}\). Funeral pyre of infected cows. Exterminating a living organism when it is infected artificially increases the virulence of the disease to something like \(\alpha\rightarrow\infty\).

This lowered \(\beta\) by containing respiratory droplets from infected individuals, and lowered the chance of infected droplets entering the respiratory systems of susceptible individuals, in turn reducing the infectivity \(\beta\). Some citizens, however, refused to wear the masks.

During the Ebola outbreak of 2014–15, amidst fears and warnings of the disease becoming established around the world, some U.S. governors ordered temporary quarantine of returning medical workers who had been in direct proximity with Ebola, until it was clear that they were not infected. At least one refused the quarantine based on individual rights, and the courts upheld the refusal.

These ethical conflicts surrounding \(\beta\) are not as grim as those surrounding \(\alpha\), with options currently practiced for domestic plants and animals but so extreme that they are never proposed for human populations.

It is curious that these high-level social dilemmas are perceptible within the most basic equations of ecology. Science can inform such ethical issues, but society must decide them.

Figure \(\PageIndex{2}\). The slogan “Obey the laws and wear the gauze” accompanied regulations intended to protect public and individual health in 1918–19 San Francisco. Thousands of city residents died of influenza, but at a rate lower than that of many other cities. Most of the public complied with the regulations; some who refused were quarantined in jail. Pictured above are police officers in Seattle in 1918.