Skip to main content Accessibility help

The helminth community of a population of Rattus norvegicus from an urban Brazilian slum and the threat of zoonotic diseases

  • Ticiana Carvalho-Pereira (a1) (a2), Fábio N. Souza (a2), Luana R. N. Santos (a2), Ruth Walker (a2), Arsinoê C. Pertile (a2), Daiana S. de Oliveira (a2), Gabriel G. Pedra (a3), Amanda Minter (a3), Maria Gorete Rodrigues (a4), Thiago C. Bahiense (a1), Mitermayer G. Reis (a1) (a2) (a5), Peter J. Diggle (a6), Albert I. Ko (a5), James E. Childs (a5), Eduardo M. da Silva (a1), Mike Begon (a3) and Federico Costa (a1) (a2) (a3) (a5)...


Urban slums provide suitable conditions for infestation by rats, which harbour and shed a wide diversity of zoonotic pathogens including helminths. We aimed to identify risk factors associated with the probability and intensity of infection of helminths of the digestive tract in an urban slum population of Rattus norvegicus. Among 299 rats, eleven species/groups of helminths were identified, of which Strongyloides sp., Nippostrongylus brasiliensis and, the human pathogen, Angiostrongylus cantonensis were the most frequent (97, 41 and 39%, respectively). Sex interactions highlighted behavioural differences between males and females, as eg males were more likely to be infected with N. brasiliensis where rat signs were present, and males presented more intense infections of Strongyloides sp. Moreover, rats in poor body condition had higher intensities of N. brasiliensis. We describe a high global richness of parasites in R. norvegicus, including five species known to cause disease in humans. Among these, A. cantonensis was found in high prevalence and it was ubiquitous in the study area – knowledge which is of public health importance. A variety of environmental, demographic and body condition variables were associated with helminth species infection of rats, suggesting a comparable variety of risk factors for humans.


Corresponding author

Author for correspondence: Ticiana Carvalho-Pereira, E-mail:


Hide All
Adejinmi, JO and Emikpe, GE (2011) Helminth parasites of some wildlife in Asejire Game Reserve, Nigeria. South African Journal of Wildlife Research 41, 214217.
Alicata, JE (1965) Biology and distribution of the rat lungworm, Angiostrongylus cantonensis, and its relationship to eosinophilic meningoencephalitis and other neurological disorders of man and animals. Advances in Parasitology 3, 223248.
Almeida, A, Corrigan, R and Sarno, R (2013) The economic impact of commensal rodents on small businesses in Manhattan's Chinatown: trends and possible causes. Suburban Sustainability 1, 112.
Alruzug, IM, Khormi, MM and Alhanoo, IK (2016) Hymenolepis nana human diagnosed through colonoscopy: a case report. Bacteriology & Parasitology 7, 265.
Araújo, P (1967) Helmintos de Rattus norvegicus (Berkenhout, 1769) da cidade de São Paulo. Revista da Faculdade de Farmácia e Bioquímica da Universidade de São Paulo 5, 141159.
Bartlett, MS, Harper, K, Smith, N, Verbanac, P and Smith, JW (1978) Comparative evaluation of a modified zinc sulfate flotation technique. Journal of Clinical Microbiology 7, 524528.
Beldomenico, PM and Begon, M (2010) Disease spread, susceptibility and infection intensity: vicious circles? Trends in Ecology & Evolution 25, 2127.
Calhoun, JB (1962) The Ecology and Sociology of the Norway Rat. US Department of Health Education and Welfare, Public Health Service Publication No. 1008, USA.
Carvalho, OS, Scholte, RGC, Mendonça, CLF, Passos, LKJ and Caldeira, RL (2012) Angiostrongylus cantonensis (Nematode: Metastrongyloidea) in molluscs from harbour areas in Brazil. Memórias do Instituto Oswaldo Cruz 107, 740746.
Childs, JE, McLafferty, SL, Sadek, R, Miller, GL, Khan, AS, DuPree, ER, Advani, R, Mills, JN and Glass, GE (1998) Epidemiology of rodent bites and prediction of rat infestation in New York city. American Journal of Epidemiology 148, 7887.
Costa, F, Ribeiro, GS, Felzemburgh, RDM, Santos, N, Reis, RB, Santos, AC, Fragal, DBM, Araujo, WN, Santana, C, Childs, JE, Reis, MG and Ko, AI (2014 a) Influence of household rat infestation on Leptospira transmission in the urban slum environment. PLoS Neglected Tropical Diseases 8, e3338.
Costa, F, Porter, FH, Rodrigues, G, Farias, H, de Faria, MT, Wunder, EA, Osikowicz, LM, Kosoy, MY, Reis, MG, Ko, AI and Childs, JE (2014 b) Infections by Leptospira interrogans, seoul virus, and Bartonella spp. Among Norway rats (Rattus norvegicus) from the Urban Slum Environment in Brazil. Vector-Borne and Zoonotic Diseases 14, 3340.
Costa, F, Hagan, JE, Calcagno, J, Kane, M, Torgerson, P, Martinez-Silveira, MS, Stein, C, Abela-Ridder, B and Ko, AI (2015 a) Global morbidity and mortality of leptospirosis: a systematic review. PLoS Neglected Tropical Diseases 9, e0003898.
Costa, F, Wunder, EA Jr., De Oliveira, D, Bisht, V, Rodrigues, G, Reis, MG, Ko, AI, Begon, M and Childs, JE (2015 b) Patterns in Leptospira Shedding in Norway rats (Rattus norvegicus) from Brazilian Slum Communities at high risk of disease transmission. PLoS Neglected Tropical Diseases 9, e0003819.
Crawley, MJ (2007) The R Book. 1st edn. Chichester, UK: John Wiley & Sons, Ltd.
Cringoli, G, Rinaldi, L, Veneziano, V, Capelli, G and Scala, A (2004) The influence of flotation solution, sample dilution and the choice of McMaster slide area (volume) on the reliability of the McMaster technique in estimating the faecal egg counts of gastrointestinal strongyles and Dicrocoelium dendriticum in sheep. Veterinary Parasitology 123, 121131.
De Faria, MT, Calderwood, MS, Athanazio, DA, McBride, AJA, Hartskeerl, RA, Pereira, MM, Ko, AI and Reis, MG (2008) Carriage of Leptospira interrogans among domestic rats from an urban setting highly endemic for leptospirosis in Brazil. Acta Tropica 108, 15.
Dineen, JK and Kelly, JD (1973) Immunological unresponsiveness of neonatal rats to infection with Nippostrongylus brasiliensis the competence of neonatal lymphoid cells in worm expulsion. Immunology 25, 141150.
Falcón-Ordaz, J, Pulido-Flores, G and Monks, S (2010) New species of Aspiculuris (Nematoda: Heteroxynematidae), parasite of Mus musculus (Rodentia: Muridae), from Hidalgo, Mexico. Revista Mexicana de Biodiversidad 81, 669676.
Faust, EC, D'Antoni, JS, Odom, V, Miller, MJ, Peres, C, Sawitz, W, Thomen, LF, Tobie, J and Walker, JH (1938) A critical study of clinical laboratory technics for the diagnosis of protozoan cysts and helminth eggs in feces I. Preliminary communication. American Journal of Tropical Medicine 18, 169183.
Felzemburgh, RDM, Ribeiro, GS, Costa, F, Reis, RB, Hagan, JE, Melendez, AXTO, Fraga, D, Santana, FS, Mohr, S, dos Santos, BL, Silva, AQ, Santos, AC, Ravines, RR, Tassinari, WS, Carvalho, MS, Reis, MG and Ko, AI (2014) Prospective study of leptospirosis transmission in an Urban Slum Community: role of poor environment in repeated exposures to the Leptospira agent. PLoS Neglected Tropical Diseases 8, e2927.
Garcia, MHO, Moraes, C, Almada, GL and Araújo, WN (2008) Investigação de casos de meningite eosinofílica causada pela infecção por angiostrongylus cantonensis no Espírito Santo, Brasil. Secretaria de Vigilância em Saúde – Boletim Eletrônico Epidemiológico, 8, 15.
Gillespie, TR and Chapman, CA (2006) Prediction of parasite infection dynamics in primate metapopulations based on attributes of forest fragmentation. Conservation Biology 20, 441448.
Glass, GE, Childs, JE, Korch, GW and LeDuc, JW (1988) Association of intraspecific wounding with hantaviral infection in wild rats (Rattus norvegicus). Epidemiology & Infection 101, 459472.
Gómez Villafañe, IE, Robles, MR and Busch, M (2008) Helminth communities and host-parasite relationships in argentine brown rat (Rattus norvegicus). Helminthologia 45, 126129.
Gordon, H Mcl. and Whitlock, HV (1939) A new technique four counting nematode eggs in sheep faeces. Journal of Scientific & Industrial Research 12, 5052.
Hacker, KP, Minter, A, Begon, M, Diggle, PJ, Serrano, S, Reis, MG, Childs, JE, Ko, AI and Costa, F (2016) A comparative assessment of track plates to quantify fine scale variations in the relative abundance of Norway rats in urban slums. Urban Ecosystems 19, 561575.
Hagan, JE, Moraga, P, Costa, F, Capian, N, Ribeiro, GS, Wunder, EA Jr., Felzemburgh, RDM, Reis, RB, Nery, N, Santana, FS, Fraga, D, dos Santos, BL, Santos, AC, Queiroz, A, Tassinari, W, Carvalho, MS, Reis, MG, Diggle, PJ and Ko, AI (2016) Spatiotemporal determinants of urban leptospirosis transmission: four-year prospective Cohort study of slum residents in Brazil. PLoS Neglected Tropical Diseases 10, e0004275.
Hancke, D, Navone, GT and Suarez, OV (2011) Endoparasite community of Rattus norvegicus captured in a shantytown of Buenos Aires City. Helminthologia 48, 167173.
Himsworth, CG, Jardine, CM, Parsons, KL, Feng, AYT and Patrick, DM (2014) The characteristics of wild rat (Rattus spp.) populations from an inner-city neighborhood with a focus on factors critical to the understanding of rat-associated zoonoses. PLoS One 9, e91654.
Hoffman, WA, Pons, JA and Janer, JL (1934) Sedimentation concentration method in schistosomiasis mansoni. Puerto Rico Journal of Public Health and Tropical Medicine 9, 283298.
Hurvich, CM and Tsai, C-L (1989) Regression and time series model selection in small samples. Biometrika 76, 297307.
Instituto Brasileiro de Geografia e Estatística (IBGE) (2010), last accessed in the 11th of February 2017.
Jarret, EEE, Jarret, WFH and Urquhart, GM (1966) Immunological unresponsiveness in adult rats to the nematode Nippostrongylus brasiliensis induced by infection in early life. Nature 211, 13101311.
Jarret, EEE, Jarret, WFH and Urquhart, GM (1968) Immunological unresponsiveness to Helminth parasites: I. The pattern of Nippostrongylus brasiliensis infection in young rats. Experimental Parasitology 23, 151160.
Kataranovski, D, Kataranovski, M and Deljanin, I (2010) Helminth fauna of Rattus Norvegicus Berkenhout, 1769 from the Belgrade area, Serbia. Archives of Biological Sciences 62, 10911099.
Klein, SL (2000) The effects of hormones on sex differences in infection: from genes to behavior. Neuroscience & Biobehavioral Reviews 24, 627638.
Ko, AI, Reis, MG, Dourado, CMR, Johnson, WD Jr., Riley, LW, Ferrer, SR, Guerreiro, H, Salgado, K, Pereira, MM, Velloso, LF, Carvalho, CC, de Codes, LMG, Orrico, GS, Tavares-Neto, J, Pereira, MM and Lee, S (1999) Urban epidemic of severe leptospirosis in Brazil. The Lancet 354, 820825.
Kunwar, CB, Subba, B, Shrestha, M, Chapagain, RH, Jha, B, Subedi, J, Blangero, J, Williams Blangero, S and Towne, B (2005) A human case of Hymenolepis diminuta infection in Nepal. Journal of Institute of Medicine 27, 6667.
Lescano, SZ, Queiroz, ML and Chieffi, PP (2004) Larval recovery of Toxocara canis in organs and tissues of experimentally infected Rattus norvegicus. Memórias do Instituto Oswaldo Cruz 99, 627628.
Levecke, B, Behnke, JM, Ajjampur, SSR, Albonico, M, Ame, SM, Charlier, J, Geiger, SM, Hoa, NTV, Kamwa Ngassam, RI, Kotze, AC, McCarthy, JS, Montresor, A, Periago, MV, Roy, S, Tchuem Tchuenté, L-A, Thach, DTC and Vercruysse, J (2011) A comparison of the sensitivity and fecal egg counts of the McMaster egg counting and Kato-Katz thick smear methods for soil-transmitted helminths. PLoS Neglected Tropical Diseases 5, e1201.
Long, JL (2003) Introduced Mammals of the World. Collingwood, Victoria, AU: CSIRO Publishing and Wallingford, UK: CABI Publishing.
Lo Re, V III and Gluckman, SJ (2003) Eosinophilic meningitis. American Journal of Medicine 114, 217223.
Lynsdale, CL, Franco dos Santos, DJ, Hayward, AD, Mar, KU, Htut, W, Aung, HH, Soe, AT and Lummaa, V (2015) A standardised faecal collection protocol for intestinal helminth egg counts in Asian elephants, Elephas maximus. International Journal for Parasitology: Parasites and Wildlife 4, 307315.
Martins, AV and Pessôa, SB (1977) Pessôa Parasitologia Médica, 10th edn. Rio de Janeiro, BR: Editora Guanabara-Koogan.
McGarry, JW, Higgins, A, White, NG, Pounder, KC and Hetzel, U (2015) Zoonotic helminths of urban brown rats (Rattus norvegicus) in the UK: neglected public health considerations? Zoonoses and Public Health 62, 4452.
Mercer, JG, Mitchell, PI, Moar, KM, Bissett, A, Geissler, S, Bruce, K and Chappell, LH (2000) Anorexia in rats infected with the nematode, Nippostrongylus brasiliensis: experimental manipulations. Parasitology 120, 641647.
Mills, JN, Childs, JE, Ksiazek, TG, Peters, CJ and Velleca, WM (1995) Methods for trapping and sampling small mammals for virologic testing. U.S. Department of Health & Human Services, Edn. Atlanta, USA, 61p.
Mirdha, BR and Samantray, JC (2002) Hymenolepis nana: a common cause of paediatric diarrhoea in Urban Slum Dwellers in India. Journal of Tropical Pediatrics 48, 331334.
Mohd Zain, SN, Behnke, JM and Lewis, JW (2012) Helminth communities from two urban rat populations in Kuala Lumpur, Malaysia. Parasites & Vectors 5, 123.
Morassutti, AL, Thiengo, SC, Fernandez, M, Sawanyawisuth, K and Graeff-Teixeira, C (2014) Eosinophilic meningitis caused by Angiostrongylus cantonensis: an emergent disease in Brazil. Memórias do Instituto Oswaldo Cruz 109, 399407.
Moreira, VLC, Giese, EG, Melo, FTV, Simões, RO, Thiengo, SC, Maldonado, A Jr. and Santos, JN (2013) Endemic angiostrongyliasis in the Brazilian Amazon: Natural parasitism of Angiostrongylus cantonensis in Rattus rattus and R. norvegicus, and sympatric giant African land snails. Achatina fulica, Acta Tropica 125, 9097.
Nursyazana, MT, Mohdzain, SN and Jeffery, J (2013) Biodiversity and macroparasitic distribution of the wild rat population of Carey Island, Klang. Tropical Biomedicine 30, 199210.
Ooi, GL and Phua, KH (2007) Urbanization and slum formation. Journal of Urban Health 84, i27i34.
Panti-May, JA, Carvalho-Pereira, TSA, Serrano, S, Pedra, GG, Taylor, J, Pertile, AC, Minter, A, Airam, V, Carvalho, M, Júnior, NN, Rodrigues, G, Reis, MG, Ko, AI, Childs, JE, Begon, M and Costa, F (2016) A two-year ecological study of Norway rats (Rattus norvegicus) in a Brazilian Urban Slum. PLoS ONE 11, e0152511.
Patamia, I, Cappello, E, Castellano-Chiodo, D, Greco, F, Nigro, L and Cacopardo, B (2010) A human case of Hymenolepis diminuta in a child from Eastern Sicily. The Korean Journal of Parasitology 48, 167169.
Peig, J and Green, AJ (2009) New perspectives for estimating body condition from mass/length data: the scaled mass index as an alternative method. Oikos 118, 18831891.
Pinto, HA, Mati, VLT and Melo, AL (2014) Toxocara cati (Nematoda: Ascarididae) in Didelphis albiventris (Marsupialia: Didelphidae) from Brazil: a case of pseudoparasitism. Revista Brasileira de Parasitologia Veterinária 23, 522525.
Puckett, EE, Park, J, Combs, M, Blum, MJ, Bryant, JE, Caccone, A, Costa, F, Deinum, EE, Esther, A, Himsworth, CG, Keightley, PD, Ko, A, Lundkvist, A, McElhinney, LM, Morand, S, Robins, J, Russell, J, Strand, TM, Suarez, O, Yon, L and Munshi-South, J (2016) Global population divergence and admixture of the brown rat (Rattus norvegicus) Proceedings of the Royal Society of London B 283, 20161762.
Rafique, A, Rana, SA, Khan, HA and Sohail, A (2009) Prevalence of some helminths in rodents captured from different city structures including poultry farms and human population of Faisalabad, Pakistan. Pakistan Veterinary Journal 29, 141144.
R Development Core Team (2011) R: A Language and Environment for Statistical Computing. Vienna, AT: R Foundation for Statistical Computing. ISBN 3-900051-07-0. Last accessed in the 20th of May 2013.
Reis, RB, Ribeiro, GS, Felzemburgh, RDM, Santana, FS, Mohr, S, Melendez, AXTO, Queiroz, A, Santos, AC, Ravines, RR, Tassinari, WS, Carvalho, MS, Reis, MG and Ko, AI (2008) Impact of environment and social gradient on Leptospira infection in urban slums. PLoS Neglected Tropical Diseases 2, e228.
Riley, LW, Ko, AI, Unger, A and Reis, MG (2007) Slum health: diseases of neglected populations. BMC International Health and Human Rights 7, 16.
Santos, NJ, Sousa, E, Reis, MG, Ko, AI and Costa, F (2017) Rat infestation associated with environmental deficiencies in an urban slum community with high risk of leptospirosis transmission. Cadernos de Saúde Pública 33, e00132115.
Santos, SV, Lescano, SZ, Castro, JM and Chieffi, PP (2009) Larval recovery of Toxocara cati in experimentally infected Rattus norvegicus and analysis of the rat as potential reservoir for this ascarid. Memórias do Instituto Oswaldo Cruz 104, 933934.
Schantz, PM (1996) Tapeworms (Cestodiasis). Gastroenterology Clinics of North America 25, 637653.
Schnyder, M, Maurelli, MP, Morgoglione, ME, Kohler, L, Deplazes, P, Torgerson, P, Cringoli, G and Rinaldi, L (2011) Comparison of faecal techniques including FLOTAC for copromicroscopic detection of first stage larvae of Angiostrongylus vasorum. Parasitology Research 109, 6369.
Simões, RO, Luque, JL, Gentile, R, Rosa, MCS, Costa-Neto, S and Maldonado, A Jr. (2016) Biotic and abiotic effects on the intestinal helminth community of the brown rat Rattus norvegicus from Rio de Janeiro, Brazil. Journal of Helminthology 90, 2127.
Singleton, GR, Hinds, LA, Krebs, CJ and Spratt, DM (2003) Rats, Mice and People: Rodent Biology and Management. Australian Centre for International Agricultural Research Monograph no. 96, Canberra, AU, 564p.
Tena, D, Pérez Simón, M, Gimeno, C, Pérez Pomata, MT, Illescas, S, Amondarain, I, González, A, Domínguez, J and Bisquert, J (1998) Human infection with Hymenolepis diminuta: case report from Spain. Journal of Clinical Microbiology 36, 23752376.
Thiengo, SC, Faraco, FA, Salgado, NC, Cowie, RH and Fernandez, MA (2007) Rapid spread of an invasive snail in South America: the giant African snail, Achatina fulica, in Brasil. Biological Invasions 9, 693702.
Tiwari, S, Karuna, T and Rautaraya, B (2014) Hymenolepis diminuta infection in a child from a rural area: a rare case report. Journal of Laboratory Physicians 6, 5859.
United Nations (2003) The Challenge of Slums: Global Report on Human Settlements. London: UN Human Settlements Programme and London, UK: Sterling, Earthscan Publications Ltd., 310 p.
United Nations (2005) Investing in Development: A Practical Plan to Achieve the Millennium Development Goals. New York, USA: UN Millennium Project.
United Nations (2016) Urbanization and Development: Emerging Features. UN-Habitat World Cities Report 2016, UN Human Settlements Programme, Nairobi, Kenya, 262 p.
Vadell, MV, Gómez Villafañe, IE and Cavia, R (2014) Are life-history strategies of Norway rats (Rattus norvegicus) and house mice (Mus musculus) dependent on environmental characteristics? Wildlife Research 41, 172184.
Vicente, JJ, Rodrigues, HO, Gomes, DC and Pinto, RM (1997) Nematóides do Brasil. Parte V: nematóides de mamíferos. Revista Brasileira de Zoologia 14, 1452.
Walker, R, Carvalho-Pereira, T, Serrano, S, Pedra, G, Hacker, K, Taylor, J, Minter, A, Pertile, A, Panti-May, A, Carvalho, M, Souza, FN, Nery, N Jr., Rodrigues, G, Bahiense, T, Reis, MG, Ko, AI, Childs, JE, Begon, M and Costa, F (2017) Factors affecting carriage and intensity of infection of Calodium hepaticum within Norway rats (Rattus norvegicus) from an urban slum environment in Salvador, Brazil. Epidemiology & Infection 145, 334338.
Wang, Q-P, Lai, D-H, Zhu, X-Q, Chen, X-G and Lun, Z-R (2008) Human angiostrongyliasis. The Lancet Infectious Diseases 8, 621630.
Wang, Q-P, Wu, Z-D, Wei, J, Owen, RL and Lun, Z-R (2012) Human Angiostrongylus cantonensis: an update. European Journal of Clinical Microbiology & Infectious Diseases 31, 389395.
Waugh, CA, Lindo, JF, Foronda, P, Ángeles-Santana, M, Lorenzo-Morales, J and Robinson, RD (2006) Population distribution and zoonotic potential of gastrointestinal helminths of wild rats Rattus Rattus and R. Norveg icus from Jamaica. Journal of Parasitology 2, 10141018.
Webster, JP and Macdonald, DW (1995) Parasites of wild brown rats (Rattus norvegicus) on UK farms. Parasitology 111, 247255.
Wolff, JO (2003) Density-dependence and the socioecology of space use in rodents. In Singleton, GR, Hinds, LA, Krebs, CJ and Spratt, DM (eds). Rats, Mice and People: Rodent Biology and Management, pp. 124130. Australian Centre for International Agricultural Research Monograph No. 96. Canberra, AU.
Zuk, M (1990) Reproductive strategies and disease susceptibility: an evolutionary viewpoint. Parasitology Today 6, 231233.


Related content

Powered by UNSILO
Type Description Title
Supplementary materials

Carvalho-Pereira et al supplemantary material 1
Supplementary Figure

 PDF (5.8 MB)
5.8 MB
Supplementary materials

Carvalho-Pereira et al supplemantary material 2
Supplementary Figure

 Unknown (20 KB)
20 KB
Supplementary materials

Carvalho-Pereira et al supplemantary material 3
Supplementary Figure

 Unknown (338 KB)
338 KB
Supplementary materials

Carvalho-Pereira et al supplemantary material 4
Supplementary Table

 Word (16 KB)
16 KB
Supplementary materials

Carvalho-Pereira et al supplemantary material 5
Supplementary Table

 Word (22 KB)
22 KB
Supplementary materials

Carvalho-Pereira et al supplemantary material 6
Figure legends

 Word (13 KB)
13 KB

The helminth community of a population of Rattus norvegicus from an urban Brazilian slum and the threat of zoonotic diseases

  • Ticiana Carvalho-Pereira (a1) (a2), Fábio N. Souza (a2), Luana R. N. Santos (a2), Ruth Walker (a2), Arsinoê C. Pertile (a2), Daiana S. de Oliveira (a2), Gabriel G. Pedra (a3), Amanda Minter (a3), Maria Gorete Rodrigues (a4), Thiago C. Bahiense (a1), Mitermayer G. Reis (a1) (a2) (a5), Peter J. Diggle (a6), Albert I. Ko (a5), James E. Childs (a5), Eduardo M. da Silva (a1), Mike Begon (a3) and Federico Costa (a1) (a2) (a3) (a5)...


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.