Differential pathogenicity and lethality of bubonic plague (1720-1945) by sex, age and place.

COVID-19 brought back to the attention of the scientific community that males are more susceptible to infectious diseases. What is clear for other infections-that sex and gender differences influence both risk of infection and mortality-is not yet fully elucidated for plague, particularly bubonic plague, although this knowledge can help find specific defences against a disease for which a vaccine is not yet available. To address this question, we analysed data on plague from hospitals in different parts of the world since the early eighteenth century, which provide demographic information on individual patients, diagnosis and course of the disease in the pre-antibiotic era. Assuming that the two sexes were equally represented, we observe a worldwide prevalence of male cases hospitalized at any age, a result which seems better explained by gender-biased (thus cultural) behaviours than biological sex-related factors. Conversely, case fatality rates differ among countries and geographic macro-areas, while globally, lethality appears slightly prevalent in young females and older adults (regardless of sex). Logistic regression models confirm that the main risk factor for bubonic plague death was the geographical location of the cases and being older than 50 years, whereas sex only showcased a slight trend.

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

In historical times, plague epidemics intermittently ravaged Europe for more than 1,400 years, and still represent a threat in many countries all over the world. A debate is ongoing about the past plague, if it killed randomly in a population or discriminated among persons on the basis of their biological features. To address questions of plague lethality, we reviewed a large number of anthropological studies published in the last twenty years on victims of the past pestilences in Europe. In particular, we focused on data concerning demography (age at death and sex determination), and health status (skeletal biomarkers). We applied to these data a model system based on Multiple Linear Regression, which aimed to discern among possible predictors of sex-selective plague lethality in entire populations, in different periods and regions. Based on available data, we lack evidence for general trends of association between biological features. Differences in sex ratio are more likely due to the original population compositions or to distinct cultural behaviours of the two genders. We concluded that generalizations on biological evidence are not feasible for ancient plagues if we exclude that the infection possibly killed primarily persons between 5-10 and 20-35 years of age.

Changes in lung function during an extreme mountain ultramarathon.

This study aimed to assess the effects of an extreme mountain ultramarathon (MUM, 330 km, 24,000 D+) on lung function. Twenty-nine experienced male ultramarathon runners performed longitudinally [before (pre), during (mid), and immediately after (post) a MUM] a battery of pulmonary function tests. The tests included measurements of forced vital capacity, forced expiratory volume in 1 s, peak flow, inspiratory capacity, and maximum voluntary ventilation in 12 s (MVV12). A significant reduction in the running speed was observed (-43.0% between pre-mid and mid-post; P < 0.001). Expiratory function declined significantly at mid (P < 0.05) and at post (P < 0.05). A similar trend was observed for inspiratory function (P < 0.05). MVV12 declined at mid (P < 0.05) and further decreased at post (P < 0.05). Furthermore, there are significant negative correlations between performance time and MVV12 pre-race (R = -0.54, P = 0.02) as well as changes in MVV12 between pre- and post-race (R = -0.53, P = 0.009). It is concluded that during an extreme MUM, a continuous decline in pulmonary function was observed, likely attributable to the high levels of ventilation required during this MUM in a harsh mountainous environment.