British squirrels infected with leprosy
With the exception of armadillos in the Americas, leprosy infections are considered almost exclusively restricted to humans. Avanzi
et al.
examined warty growths on the faces and extremities of red squirrels in the British Isles and found that two species of leprosy-causing organisms were to blame (see the Perspective by Stinear and Brosch).
Mycobacterium leprae
in the southern population of Brownsea Island squirrels originated from a medieval human strain.
M. lepromatosis
was found in red squirrels from elsewhere in the United Kingdom and Ireland. Human leprosy is proving hard to eradicate, despite available drugs. Perhaps other wildlife species are also reservoirs for this stubborn disease.
Science
, this issue p.
744
; see also p.
702
Chronic inhalation of crystalline silica and silicates may lead to severe lung disease in humans, termed silicosis. The disease is an occupational health concern in miners and related professions worldwide. Silicosis is also a strong risk factor for tuberculosis in humans. Due to its subterranean lifestyle, the European badger (Meles meles) is continuously exposed to environmental dust, while this species is also susceptible to tuberculosis, caused by Mycobacterium bovis. To date, a thorough investigation of mineral dust retention and its possible implication as a risk factor for mycobacterial infection in badgers has not been performed. The aims of this retrospective histological study were (1) to describe the systemic tissue distribution of silica-laden macrophages (SLMs) in badgers; (2) to compare the amount of SLMs in tissues of badgers of differing M. bovis infection status, pulmonary SLM burden and age; and (3) to assess whether inflammation was associated with SLMs. We assessed lung, lymph nodes, liver and spleen of 60 wild-caught badgers of known M. bovis infection status for the presence of SLMs using polarizing light microscopy. SLMs were consistently present within the lungs and were widely distributed throughout the lymphatic system. No inflammatory reaction to SLMs, as occurs in human silicosis, was observed in any tissue. Distribution and amount of SLMs were similar between M. bovis positive and negative badgers, and we were not able to show an association between the amount of SLMs and M. bovis infection status. The amount of SLMs within intra- and extrathoracic lymph nodes was positively associated with the amount of pulmonary SLMs, and with age. This is the first report of substantial and systemic tissue retention of mineral dust particles in a mammalian species lacking associated chronic inflammation (i.e. silicosis). We further highlight different pathogenetic mechanisms underlying silicosis and benign SLM accumulations following siliceous dust inhalation.
A 20-year-old zoo-born female gravid white-naped mangabey (Cercocebus lunulatus) was found dead adjacent to a pool of blood. The uterus contained one female fetus in breech malposition that was developed to term. The cervix was fully dilated and fetal membranes had ruptured indicating early parturition. The placenta was located ventrally within the posterior uterus and fully blocked the os cervix. It showed multiple areas of acute haemorrhage, and was considered the source of fatal peripartum maternal haemorrhage. These findings are consistent with a diagnosis of placenta previa, an abnormal implantation of the placenta in the lower uterine segment in humans and other primates. Risk factors reported in humans, which were also present in this monkey, include pluriparity, increased maternal age and the possibility of dystocia during previous pregnancies. To our knowledge, this is the first report of placenta previa in mangabeys.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.