Saliva de animais hematófagos: fonte de novos anticoagulantes

High risk of bat bites in an indigenous village in Brazil: Warning of the re-emergence of rabies among the Maxakali People

Bat-mediated human rabies is a viral zoonotic disease that poses a serious threat to the public health of traditional peoples, especially indigenous populations that maintain primitive cultural and social habits, such as the Maxakali ethnic group, located in the southeastern region of Brazil. The sociocultural habit of this population led to the emergence between April and May 2022 of the viral spillover of rabies transmitted by bats, which decimated the lives of four children from this population who maintained contact with this animal as a recreational practice. Because the vampire bats Desmodus rotundus have exceptional ecology and social characteristics that can have important effects on the dynamics of viral dispersion in this indigenous population, I present the dynamics of contact between native children and the bat and the meaning of this relationship, which involves ritualistic and recreational significance. As important as knowing the reasons for this practice is discussing some intrinsic and extrinsic factors that imply risks that intensify the vulnerability of this population to the transmission of the rabies virus at any time. In view of this, I warn of the need to adopt efficient strategies to mitigate the risks of a new emergency in this region. Although emergency containment measures were carried out during the critical period of the outbreak, such animal and environmental control actions must become routine programmatic and structuring interventions. Essential for rabies surveillance in this population is to develop culturally adapted interethnic health education campaigns to guarantee the accessibility of the Maxakali indigenous people to the content taught, so that any attempt at domestication, captivity and recreational practices with bats of any species is discouraged, thus avoiding a possible re-emergence of this anthropozoonosis that has impacted not only the epidemiological scenario in this region, but throughout Brazil, and also throughout Latin America.

Aspects regarding renal morphophysiology of fruit-eating and vampire bats

Bats have adapted to many different feeding habits, which are known to induce morphophysiological adaptations in several tissues, especially those particularly involved with absorption, metabolism and excretion. The common vampire bat (Desmodus rotundus) has a very unique diet (blood), which, among other challenges, seems to pose a risk to their kidneys, due to the increased nitrogen excretion imposed by their remarkably high protein meal. Fruit-eating bats (Artibeus lituratus) consume a high carbohydrate diet and may be taken as a suitable species for this dietary comparative study. Here we aimed at investigating the renal morphology and stereology, kidneys antioxidant capacity, and plasma antidiuretic hormone (ADH) concentrations in adult fruit-eating and vampire bats. Sixteen animals were captured and used in this study, being 8 adult males from each species. Our results showed higher morphological standards of glomerular area, volumetric density of glomeruli, and renal somatic index for vampire bats, as well as higher reactive species of oxygen (ROS) production, such as nitric oxide (NO), higher plasma iron reduction ability (FRAP), higher activity of the antioxidant enzyme glutathione-S-transferase (GST) and a higher malondialdehyde production (MDA) in vampires' kidneys, compared to the fruit-eating species. The activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were higher in fruit-eating bats. Plasma ADH concentrations were not different between species. Taken together, the renal morphophysiology conditions presented by vampire bats might be associated with a high demand for nitrogenous products excretion imposed by protein and iron overload. These features may play an important role on preventing protein-overload nephropathy, allowing vampires to survive under such a unique diet.