Mortality risk factors show similar trends in modern and historic populations exposed to plague

Abstract

Introduction: Plague has been responsible for two major historic pandemics (6th-8th century CE; 14th-19th century CE) and a modern one. The recent Malagasy plague outbreaks raised new concerns on the deadly potential of the plague-causing bacteria Yersinia pestis. Between September 2014 and April 2015, outbreaks of bubonic and pneumonic plague hit the Malagasy population. Two hundred and sixty-three cases, including 71 deaths, have been reported in 16 different districts with a case fatality rate of 27%. The scope of our study was to ascertain whether the risk factors for health in modern-day populations exposed to plague and in ancient populations that faced the two historic pandemics varied or remained substantially unaltered. Methodology: The risk of mortality of the Malagasy population with those obtained from the reconstruction of three samples of European populations exposed to the historic pandemics was contrasted. Results: The evidence shows that the risks of death are not uniform across age neither in modern nor in historic populations exposed to plague and shows precise concentrations in specific age groups (children between five and nine years of age and young adults). Conclusions: Although in the post-antibiotic era, the fatality rates have drastically reduced, both modern and historic populations were exposed to the same risk factors that are essentially represented by a low standard of environmental hygiene, poor nutrition, and weak health systems.

A critical review of anthropological studies on skeletons from European plague pits of different epochs

“…This is, seemingly, the only clear trend for plague lethality we could identify across sites and time. Similar peaks of mortality have already been highlighted in previous studies on single plague burials in France 58 , 59 , and in Italy 34 . Interestingly, this trend seems not to be peculiar to the Black Death, but it is present in any period and seems not to support the hypothesis of frailty due to age as an element of susceptibility to plague during the Black Death, as previously suggested 31 .…”

“…This is not the case with age at death estimations and, as a result, our comparisons were strongly limited by the use of diverse age classes in the different studies. Nevertheless, the simpler distinction between subadults and adults allowed us to confirm the existence of an inhomogeneous distribution among plague victims from different populations, as previously proposed 11 , 34 , 56 , and different periods. In general, descriptive statistics showed a more abundant presence of adults, if taken globally, and we noted many peaks of distribution between 5–10 years among subadults and 20–35 years among adults (Fig.…”

“…“non-plague”) population. Few exceptions are represented by works comparing 2–7 burial grounds 11 , 14 , 17 , 33 , 34 .…”

Plague risk in vulnerable community: assessment of Xenopsylla cheopis susceptibility to insecticides in Malagasy prisons

“…In all prisons in Madagascar, hygiene conditions are very poor and sanitation facilities are insufficient [ 8 ]. According to Rubini et al in 2016, the mortality risk factors associated with plague in the European medieval city can be found today in Malagasy detention centers [ 9 ]. In addition, rats are pests of everyday life in prisons [ 10 ].…”

“…In addition, rats are pests of everyday life in prisons [ 10 ]. Then in a case of plague outbreak, infected fleas can spread from the prison environment to the surroundings, with rats themselves, prisoners, prison guards, and visitors [ 9 ].…”