Rodent-borne diseases

Public health area

Rodents are reservoirs of a number of human diseases. Rodents can act as both intermediate infected hosts or as hosts for arthropod vectors such as fleas and ticks. Rodent populations are affected by weather conditions. In particular, warm, wet winters and springs increase rodent populations, which have been observed in recent years. Under climate change scenarios, rodent populations could be anticipated to increase in temperate zones, resulting in greater interaction between human beings and rodents and a higher risk of disease transmission, especially in urban areas. In some European countries, breakdown in sanitation and inadequate hygiene are contributing to serious rat infestations.


Since the last major plague outbreak in 1720, plague is no longer circulating in Europe - neither in human beings nor in rodent populations. Plague is a zoonosis caused by the bacterium Yersinia pestis that is spread by fleas feeding on black rats (Rattus rattus). Milder weather conditions are favourable to rodent populations, while harsh weather conditions such as heat waves might drive rodents indoors in search of water and thus increase contact with human beings. Fluctuations in the abundance of its main reservoir host have been linked to variation in plague incidence. Climatic changes in Central Asia favour conditions for the propagation of plague; it has been projected that only a 1 C degree increase in spring temperatures could result in a 50% increase in Y pestis prevalence in its reservoir host. Plague epizootics may become more frequent in central Asia and pose a threat to eastern European countries.

Hantavirus Infections

Hantaviruses are rodent-borne viruses with four genotypes circulating in Europe of which at least Puumala, Dobrava, and Saaremaa viruses are human pathogens. Human beings are at risk of exposure through the inhalation of virus aerosol from the excreta of infected rodents. . Excess proliferation of rodent populations related to climatic changes is of considerable international public-health concern. Hantavirus infection is sensitive to climatic conditions; for example, increased grass seed production following heavy precipitation has been linked to higher deer mouse densities that caused an outbreak in the Four Corners region of the (New Mexico) of the USA. Similarly, bank vole populations in Belgium are linked to tree seed production that in turn has been linked to high summer and autumn temperatures. These climatic conditions are associated with hantavirus disease incidence and can be used as early warning indicators of potential outbreaks. In other parts of Europe warm weather has also been associated with hantavirus and it is anticipated that general warming of the European climate will increase the risk of infection.


Rodent populations respond rapidly to conducive weather conditions, such as heavy precipitation events which can directly or indirectly propagate rodent-borne pathogens such as spirosis, a zoonotic bacterial disease, with an unknown, but probably high human and veterinary prevalence in eastern Europe and the Mediterranean. However, an increase in disease incidence is also related to a number of other variables such as rodent abatement strategies, human activities, land use, the contribution of each ought to be quantified.

Source: Semenza JC, Menne B. Climate Change and Infectious Diseases in Europe. Lancet ID. 2009;9:365-75.


  1. Kausrud KL, Viljugrein H, Frigessi A, Begon M, Davis S, Leirs H, Dubyanskiy V, Stenseth NC. Climatically driven synchrony of gerbil populations allows large-scale plague outbreaks. Proc Biol Sci. 2007;274(1621):1963-9.
  2. Davis S, Begon M, De Bruyn L, Ageyev VS, Klassovskiy NL, Pole SB, Viljugrein H, Stenseth NC, Leirs H. Predictive thresholds for plague in Kazakhstan. Science. 2004;304(5671):736-8.
  3. Stenseth NC, Samia NI, Viljugrein H, Kausrud KL, Begon M, Davis S, Leirs H, Dubyanskiy VM, Esper J, Ageyev VS, Klassovskiy NL, Pole SB, Chan KS. Plague dynamics are driven by climate variation. Proc Natl Acad Sci U S A. 2006;103(35):13110-5. Epub 2006 Aug 21
  4. Akiev AK, Yemelyanov PE, Labunets NF. European suslik as a possible carrier of plague in natural foci in eastern Europe. Hyg Epidemiol Microbiol Immunol. 1976;20(1):82-90.
  5. Linderholm M, Elgh F. Clinical characteristics of hantavirus infections on the Eurasian continent. Curr Top Microbiol Immunol. 2001;256:135-51.
  6. Kausrud KL, Viljugrein H, Frigessi A, Begon M, Davis S, Leirs H, Dubyanskiy V, Stenseth NC. Climatically driven synchrony of gerbil populations allows large-scale plague outbreaks. Proc Biol Sci. 2007;274(1621):1963-9.
  7. Anyamba A, Chretien JP, Small J, Tucker CJ, Linthicum KJ. Developing global climate anomalies suggest potential disease risks for 2006-2007. Int J Health Geogr. 2006;28;5:60.
  8. Engelthaler DM, Mosley DG, Cheek JE, Levy CE, Komatsu KK, Ettestad P, Davis T, Tanda DT, Miller L, Frampton JW, Porter R, Bryan RT. Climatic and environmental patterns associated with hantavirus pulmonary syndrome, Four Corners region, United States. Emerg Infect Dis. 1999;5(1):87-94.
  9. Hjelle B, Glass GE. Outbreak of hantavirus infection in the Four Corners region of the United States in the wake of the 1997-1998 El Nino-southern oscillation. J Infect Dis. 2000;181(5):1569-73.
  10. Tamerius J, Wise E, Uejio C, McCoy A, Comrie A. Climate and human health: synthesizing environmental complexity and uncertainty. Stochastic Environmental Research and Risk Assessment, 2007; 21 (5): 601-613.
  11. Tersago K, Verhagen R, Servais A, Heyman P, Ducoffre G, Leirs H. Hantavirus disease (nephropathia epidemica) in Belgium: effects of tree seed production and climate. Epidemiol Infect. 2009;137(2):250-6.
  12. Pejcoch M, Kriz B (2006) Ecology, Epidemiology and Prevention of Hantavirus in Europe. In Climate Change and Adaptation Strategies for Human Health [B. Menne and K Ebi (eds)]. Steinkopff, Darmstadt, 243-57.
  13. Pettersson L, Boman J, Juto P, Evander M, Ahlm C. Outbreak of Puumala virus infection, Sweden. Emerg Infect Dis. 2008;14(5):808-10.
  14. Pappas G, Papadimitriou P, Siozopoulou V, Christou L, Akritidis N. The globalization of leptospirosis: worldwide incidence trends. Int J Infect Dis. 2008;12(4):351-7
  15. Tassinari WS, Pellegrini DC, Sá CB, Reis RB, Ko AI, Carvalho MS. Detection and modelling of case clusters for urban leptospirosis. Trop Med Int Health. 2008;13:503-12.