Rodents are the most abundant and diversified order of living mammals in the world. Already since the Middle Ages we know that they can contribute to human disease, as black rats were associated with distribution of plague. However, also in modern times rodents form a threat for public health. In this review article a large number of pathogens that are directly or indirectly transmitted by rodents are described. Moreover, a simplified rodent disease model is discussed.

Rodent-borne diseases and their risks for public health

Nephropathia epidemica (NE), an emerging rodent-borne viral disease, has become the most important cause of infectious acute renal failure in Belgium, with sharp increases in incidence occurring for more than a decade. Bank voles are the rodent reservoir of the responsible hantavirus and are known to display cyclic population peaks. We tried to relate these peaks to the cyclic NE outbreaks observed since 1993. Our hypothesis was that the ecological causal connection was the staple food source for voles, being seeds of deciduous broad-leaf trees, commonly called "mast". We also examined whether past temperature and precipitation preceding "mast years" were statistically linked to these NE outbreaks. Since 1993, each NE peak is immediately preceded by a mast year, resulting in significantly higher NE case numbers during these peaks (Spearman R = -0.82; P = 0.034). NE peaks are significantly related to warmer autumns the year before (R = 0.51; P < 0.001), hotter summers two years before (R = 0.32; P < 0.001), but also to colder (R = -0.25; P < 0.01) and more moist summers (R = 0.39; P < 0.001) three years before. Summer correlations were even more pronounced, when only July was singled out as the most representative summer month. NE peaks in year 0 are induced by abundant mast formation in year-1, facilitating bank vole survival during winter, thus putting the local human population at risk from the spring onwards of year 0. This bank vole survival is further promoted by higher autumn temperatures in year-1, whereas mast formation itself is primed by higher summer temperatures in year-2. Both summer and autumn temperatures have been rising to significantly higher levels during recent years, explaining the virtually continuous epidemic state since 2005 of a zoonosis, considered rare until recently. Moreover, in 2007 a NE peak and an abundant mast formation occurred for the first time within the same year, thus forecasting yet another record NE incidence for 2008. We therefore predict that with the anticipated climate changes due to global warming, NE might become a highly endemic disease in Belgium and surrounding countries.

https://link.springer.com/content/pdf/10.1186%2F1476-072X-8-1.pdf

Relating increasing hantavirus incidences to the changing climate: the mast connection

Hantaviruses are rodent-borne, emerging viruses that cause life-threatening human diseases in Eurasia and the Americas. We detected hantavirus genome sequences in an African wood mouse (Hylomyscus simus) captured in Sangassou, Guinea. Sequence and phylogenetic analyses of the genetic material demonstrate a novel hantavirus species, which we propose to name "Sangassou virus."

/pdf/hantavirus-in-african-wood-mouse-guinea-fnkeg2d71m.pdf

Hantavirus in African wood mouse, Guinea.

Different definitions of acute renal failure (ARF) abound. The existence of multiple definitions makes it difficult to determine the true epidemiological characteristics of this condition. Despite this difficulty, it has been possible to detect notable variations in the epidemiology of ARF during the past few decades. The absolute incidence of ARF has increased, while associated mortality rate has remained relatively static. Several factors have contributed to this altered epidemiology. Here, we discuss the relative contribution of these factors, which include site of disease onset (developed or developing countries, community or hospital or intensive care unit), patient age, infections (HIV, malaria, leptospirosis and hantavirus), concomitant illnesses (cardiopulmonary failure, hemato-oncological disease), and interventions (hematopoietic progenitor cell and solid organ transplantation).

The changing epidemiology of acute renal failure

Viral hemorrhagic fevers

Hantaviruses are rodent-borne bunyaviruses that are associated with two main clinical diseases in humans: hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome. It has been suggested that host-related immune mechanisms rather than direct viral cytopathology may be responsible for the principal abnormality (vascular dysfunction) in these syndromes. This review summarizes the current knowledge on hantaviral host immune responses, immune abnormalities, laboratory diagnosis, and antiviral therapy as well as the current approaches in vaccine development.

Irina Gavrilovskaya

Papers

Hantaviruses: Immunology, Treatment, and Prevention