Synanthropic rodents are involved in the transmission of several parasitic zoonoses to humans, such as helminth parasites. As part of a multidisciplinary study concerning the rodent population in Barcelona (Spain), 300 specimens of the Norway rat, Rattus norvegicus, were analyzed to elucidate their helminth community, mainly species with a zoonotic potential. The sample included 263 specimens from the sewage system and 37 from public gardens. A total of 253 (84.3%) rats were found to be parasitized, and 206 (68.7%) harbored zoonotic species. Adult rats were found to be more heavily parasitized with zoonotic helminths than juveniles, but the sex and site of capture had no influence. Six zoonotic helminths were identified: Hydatigera taeniaeformis larvae (1.7%), Rodentolepis nana (8.0%), Hymenolepis diminuta (21.3%), Calodium hepaticum (46.3%), Gongylonema neoplasticum (36.7%), and Moniliformis moniliformis (2.3%). Human zoonotic helminth infections often go unreported, so that the role of R. norvegicus in their transmission is unknown. According to our results, it is advisable to monitor and control rodent populations in deprived settlements close to cities and in cities themselves, and to promote good hygienic and sanitary practices, especially among vulnerable populations and workers with high exposure such as sewage workers.

Mosquitoes breeding in urban sewage infrastructure are both a source of nuisance to the local population and a public health risk, given that biting mosquitoes can transmit pathogenic organisms to humans. The increasing presence of the invasive mosquito species Aedes albopictus in European cities has further exacerbated the problems already caused by native Culex pipiens. We tested the effectiveness of modifications to sewage structures as an alternative to the use of biocides to prevent mosquito breeding. The placing of a layer of concrete at the bottom of sand sewers to prevent water accumulation completely eliminated mosquito reproduction, and so eliminates the need for biocides in modified structures. Sewer modification is thus a valid low-cost alternative for mosquito control.

Abstract Background Classically, dogs have been considered to be the only reservoir of leishmaniasis in urban areas. However, in a previous study, we found a 33.3% prevalence of Leishmania infantum in the spleens of Norway rats (Rattus norvegicus) sampled in the underground sewer system of the city of Barcelona (Spain). The aim of the present study was to verify, using molecular methods, the potential reservoir role of these rats in the same sewer system. Methods A sensitive real-time PCR (qPCR) assay, DNA sequencing and phylogenetic analysis were carried out to identify and quantify the presence of L. infantum DNA in sand fly individuals captured in the same underground sewer system of Barcelona as in our previous study and in the spleens and ears of rats captured in the same sewer system. Results Leishmania infantum DNA was found in 14 of the 27 (51.9%) sand flies identified as Phlebotomus perniciosus, and 10 of the 24 (41.7%) rats studied were infected. Leishmania infantum was found in the spleens (70%) and in the ears (40%) of the infected rats. Quantitative results revealed the presence of high loads of L. infantum in the rats studied (> 3 × 106 parasites/g ear tissue) and among the sand flies (> 34 × 106 parasites in 1 individual). Conclusions The molecular methods used in this study demonstrated a high prevalence of L. infantum in the underground sewer populations of both R. norvegicus and P. perniciosus. These results suggest that sewer rats, in addition to dogs, are likely to act as reservoirs of leishmaniasis in cities, where sewer systems seem to offer the ideal scenario for the transmission of leishmaniasis. Therefore, to achieve the WHO 2030 target on the elimination of leishmaniasis as a public health problem successfully, an efficient control strategy against leishmaniasis in rats and sand flies should be implemented, particularly in the sewer systems of urban areas of endemic countries. Graphical Abstract

Control of rodent populations is a big challenge because of the rapid evolution of resistance to commonly used rodenticides and the collateral negative impacts that these products may have on biodiversity. Second-generation anticoagulants are very efficient but different single nucleotide polymorphisms (SNPs) in the Vkorc1 gene may confer resistance in rodents. We sequenced exons 1, 2 and 3 of the Vkorc1 gene from 111 mice (Mus musculus domesticus) captured across the city of Barcelona and found SNPs associated with resistance to first- and second-generation anticoagulants in all of them. Although most of the SNPs were associated with resistance to bromadiolone, we also found SNPs associated with resistance to brodifacoum. Out of all the individuals analyzed, 94.59 % carried mutations associated to introgression events with Mus spretus, a sympatric rodent species. Currently most of the chemical products for rodent control commercialized in the area are based on bromadiolone, although recent public control campaigns have already shifted to other products. Thus, the widespread occurrence of resistant mice to bromadiolone represents a challenge for rodent control in Barcelona and may increase the risk of secondary poisoning of animals preying on this species. Public health managers, pest control companies and citizens should be aware that the use of bromadiolone based products is ineffective and represents a risk for the environment, including human and animal health.

Rattus norvegicus, the brown or Norway rat, is the most abundant mammal after humans in urban areas, where they live in close proximity to people. Among rodent-borne diseases, the reservoir role of Norway rats of zoonotic parasites in cities has practically been ignored. Considering the parasitic diseases in the One Health approach, we intended to identify and quantify the zoonotic intestinal protozoans (ZIP) in an urban population of R. norvegicus in the city of Barcelona, Spain. We studied the presence of ZIP in 100 rats trapped in parks (n = 15) as well as in the city’s sewage system (n = 85) in the winter of 2016/17. The protozoans were molecularly identified by means of a multiplex PCR (AllplexTM Gastrointestinal Panel-Parasite Assay). We also investigated the presence of co-infections among the species found. Four ZIP were identified, presenting significant prevalences in sewers, specifically Blastocystis (83.5%), Giardia duodenalis (37.7%), Cryptosporidium spp. (34.1%), and Dientamoeba fragilis (14.1%). Several co-infections among the detected ZIP were also detected. The reservoir role of ZIP that Norway rats play in cities as well as the role rats may play as sentinels of zoonotic parasites affecting humans in urban areas are strongly backed up by our findings. The increasing worldwide urbanization, climate change, and the COVID-19 pandemic are factors that are producing an increase in human–rat interactions. Our results should be considered a warning to the authorities to intensify rat control and surveillance in public health interventions.

Norway rats are an important commensal species of human settlements. They are abundant in urban areas and generate several problems to our societies. Integrated rat management programs, based on detailed knowledge of its biology, are needed to keep rat populations under control. One of the main habitats of rats in cities is the sewer system. Unfortunately, very few studies have been conducted on sewer rats due to the logistic challenges of such projects. Hence, information on the ecology of rats in a key habitat, crucial to management programs, is scarce. The aim of this study is to estimate the abundance of Norway rats in the sewers of the city of Barcelona and determine the main related ecological factors. We sampled 63 sewer sections 90 m long during the study. We obtained several rat activity estimates, we compared them, we calculated a minimum rat density, and with that, we estimated the minimum rat population size in the sewer system of Barcelona. Bait consumption and rat capture estimates showed low correlations. Sewer rats showed the highest activity in areas with high density of housing and in old sections. The presence of natural soil favoured the activity of rats only inside the areas with a high density of housing. The activity of rats showed a high variability among sewer sections. The citizen complaints for rats, which were positively related to the human density and negatively related to the mean disposable household income, were bad predictors of the activity of rats in the sewer system.

We detected Leishmania infantum in 98 Norway rats (Rattus norvegicus) trapped in parks and sewers of Barcelona, Spain. The 84 rats from the sewers showed a prevalence of 33.3% and up to 2,272 estimated parasites. These results, in the most abundant potential reservoir in cities, is of public health concern.

The brown rat, Rattus norvegicus, with a worldwide distribution, is the most commensal species among synanthropic rodents, since its main habitat, in urban as well as in rural areas, is always linked to humans. Therefore, people living in close proximity to rodent populations can be exposed to infection. Whereas bacteria and viruses are the best known rat-associated zoonoses in urban environments, the role of brown rats as reservoirs for helminth parasites and the associated risk for humans are less well known. Specifically, this role has not been analyzed in Spain to date. A total of 100 R. norvegicus trapped in the sewage system (n = 85), and parks (n = 15) of Barcelona was examined. The overall prevalence of helminth infection was 85%. The helminths found were Hymenolepis nana (17%), H. diminuta (33%) (Cestoda), Calodium hepaticum (17%), Eucoleus gastricus (28%), Aonchotheca annulosa (12%), Trichosomoides crassicauda (7%), Nippostrongylus brasiliensis (46%), Heterakis spumosa (62%), Gongylonema neoplasticum (20%) (Nematoda) and Moniliformis moniliformis (6%) (Acanthocephala). Five of the ten helminth species are considered zoonotic parasites, with rats acting as reservoirs for human infection, i.e. H. nana, H. diminuta, C. hepaticum, G. neoplasticum and M. moniliformis. G. neoplasticum and M. moniliformis are reported for the first time in urban rats in Europe. H. nana, H. diminuta and C. hepaticum are the most widespread species in European cities. For H. nana and C. hepaticum, rats act as effective spreaders of the human infective stage (eggs). For H. diminuta, G. neoplasticum and M. moniliformis, rats act as indirect reservoirs of the zoonoses since the eggs shed by the rats are infective for their insect intermediate hosts only. Medical practitioners need to be made aware of the range of parasites carried by rats, as there is a realistic likelihood that ill health currently caused by rat infestations may be misdiagnosed.

62 Schistosomiasis in the Senegal River Basin and the role of wild rodents as reservoir hosts Stefano Catalano1, Elsa Léger1, Cheikh B. Fall2, Anna Borlase1, Mariama Sène3, Nicolas D. Diouf3, Khalilou Bâ4, Joanne P. Webster1 1Centre for Emerging, Endemic and Exotic Diseases (CEEED), Department of Pathobiology and Population Sciences, The Royal Veterinary College, University of London, Hatfield AL9 7TA, United Kingdom, scatalano@rvc.ac.uk 2Faculté de Médecine, de Pharmacie et d’Odontologie, Université Cheikh Anta Diop, Dakar, Senegal 3Unité de Formation et de Recherche (UFR) des Sciences Agronomiques, d’Aquaculture et de Technologies Alimentaires (S2ATA), Université Gaston Berger, Saint-Louis BP234, Senegal 4Centre de Biologie et de Gestion des Populations, Institut de Recherche pour le Développement, Campus ISRA-IRD Bel Air, Dakar, Senegal

Las infecciones por arbovirus son un grupo de enfermeda - des cuya incidencia está aumentando y que suponen un problema importante para la salud pública. El objetivo de este estudio fue describir los casos detec - tados de arbovirosis en la ciudad de Barcelona y las actuaciones de vigilancia y control realizadas para reducir el riesgo de transmisión. Métodos: Estudio descriptivo transversal de casos confirmados de den - gue, chikungunya y Zika en Barcelona durante el período de 2014 al 2016. Los casos sospechosos detectados en la ciudad se notificaron al Servicio de Epidemiología de la Agencia de Salud Pública de Barcelona (ASPB), don - de se realizó una encuesta epidemiológica y, si procedía, se contactaba con el Servicio de Vigilancia y Control de Plagas Urbanas. Desde allí se realizó la inspección entomológica y se llevaron a cabo acciones de control y segui - miento. Se recogieron variables sociodemográficas, epidemiológicas, clínicas y entomológicas de los casos. Resultados: En 2014 se detectaron 50 casos de virus chikungunya y 20 de dengue, realizándose 25 inspecciones entomológicas en domicilios y 38 en la vía pública. En 2015 se detectaron 47 casos de chikungunya, 51 de dengue y 2 de Zika, realizándose 27 inspecciones entomológicas en domicilios y 80 en vía pública. En 2016 se detectaron 17 casos de chikungunya, 52 de dengue y 48 de Zika, realizándose 50 inspecciones entomológicas en domicilio y 103 en vía pública. No se detectó ningún caso autóctono. Conclusiones: Se observó un aumento creciente de los casos de arboviro - sis durante los 3 años de estudio. Se intensificaron progresivamente las actua - ciones de vigilancia y control vectorial (inspecciones, muestras recogidas...).

ABSTRACT Seventy-two (54.5%) out of 132 fecal samples from a group of yellow-legged gulls in Barcelona, Spain, were positive for Escherichia coli producing either extended-spectrum β-lactamases (ESBL) (51.5%), carbapenemase (1.5%), or cephamycinase (1.5%). The isolation of two carbapenemase-producing E. coli strains is a matter of concern.

Background: On February 1st 2016 the WHO declared the Zika Virus (ZIKV) infection a worldwide public health emergency because of its rapid expansion and severe complications, such as Guillain-Barré Syndrome or microcephaly in newborn. The huge amount of people traveling to endemic areas and the presence of Aedes albopictus in Barcelona increase the risk of autochtonous transmission. The objective of this study was to describe the first ZIKV cases diagnosed in our city and to analyze the surveillance, prevention, and control measures implemented to avoid autochthonous transmission.Methods: An observational cross-sectional population-based study in Barcelona, Spain was performed.An analysis of the socio-demographic, epidemiological, clinical characteristics, and mosquito control activities of the ZIKV cases detected between January 1st and December 2016 was carried out using a specific ZIKV epidemiological survey of the Barcelona Public Health Agency.Results: A total of 118 notifications of possible ZIKV infections were received, and 44 corresponded to confirmed cases in Barcelona residents.Amongst these, the median age was 35 years and 57% were women. All cases were imported, 48% were Spanish-born and 52% foreign-born. Dominican Republic was the most visited country amongst foreign-born patients and Nicaragua amongst Spanish-born. The most frequent symptoms were exanthema, fever, and arthralgia. Among the 24 diagnosed women, 6 (25%) were pregnant. There was one case of microcephaly outside Barcelona city. Entomological inspections were done at the homes of 19 cases (43.2% of the total) and in 34 (77.3%) public spaces. Vector activity was found in one case of the 44 confirmed cases, and 134 surveillance and vector control were carried out associated to imported ZIKV cases. In all cases prevention measures were recommended to avoid mosquito bites on infected cases.Conclusion: Epidemiological and entomological surveillance are essential for the prevention of autochthonous transmission of arbovirosis that may have a great impact on Public Health.The good coordination between epidemiologists, entomologists, microbiologists, and clinicians is a priority in a touristic city with an intense relationship with endemic countries to minimize the risk of local transmission by competent vectors.

OBJECTIVE:Arbovirus infections are a group of diseases whose incidence is increasing and that entail an important problem for public health. The aim of this study was to describe detected cases of arbovirosis in Barcelona, and surveillance and control actions performed in order to reduce the risk of transmission.METHODS:Descriptive cross-sectional study of confirmed dengue, chikungunya and Zika cases in Barcelona during 2014-2016 (1st trimester). Suspected cases detected in the city were notified to the Epidemiology Department of the Barcelona Public Health Agency, where an epidemiological survey is undertaken and, if appropriate, Urban Pests Surveillance and Control Department is contacted. They perform an entomological inspection and implement control and monitoring actions. We collected sociodemographical, epidemiological, clinical and entomological variables.RESULTS:In 2014, 50 chikungunya and 20 dengue cases were detected; 25 entomological inspections were carried out in residences and 38 in the street. In 2015, 47 chikungunya, 51 dengue and 2 Zika cases were detected; 27 inspections were carried out in residences and 80 in the street. In 2016, 17 chikungunya, 52 dengue and 48 Zika cases were detected; 50 inspections were carried out in residences and 103 in the street. No autochtonous case was detected.CONCLUSIONS:We observed an increasing incidence of arbovirosis cases during the 3-year study period. There was a progressive intensification of vector surveillance and control actions (inspections, sample collection…).

BACKGROUND:As feeding by humans is one of the main food resources to pigeons (Columba livia), there is general agreement that public education that aims to reduce the food base may be the most feasible way to reduce pigeon abundance. However, except for the classic example of Basel, the method has rarely been tested or implemented. We provide results from a 1 year study in the city of Barcelona where we tested the effect of public education on pigeon population abundance and composition.RESULTS:The quantity of food provided by people to pigeons was significantly reduced during the study. Feral pigeon density was reduced by 40% in the two experimental districts, but no variation was detected in the control district. Detailed analyses in one of the districts showed that the reduction was mainly related to the reduction in food availability but not to culling. Pigeons captured at the end of the experiment were larger than at the start of the study, but body condition was reduced.CONCLUSION:Results show the effectiveness of public information to manage feral pigeon populations in a large city, and that control operations can exert important selection pressure on the population, leading to changes in population composition. © 2016 Society of Chemical Industry.

Objective To analyse population-based data on hospitalisation caused by dog bite injuries after changes in legal regulations on dog ownership, including breed-specific regulations.Design Descriptive study.Setting Hospitals in Catalonia (Spain), 1997-2008.Subjects Persons hospitalised with injuries caused by dog bites.Results There has been a significant decline in hospitalisation caused by injuries from dog bites from 1.80/100 000 in 1997-9 to 1.11/100 000 in 2006-8, after the enactment of stricter regulations on dog ownership in 1999 and 2002. The magnitude of this change is significant (-38%), and has been greatest in less urban settings.Conclusions Government regulations were associated with a sizable decrease in injuries caused by dog bites in Catalonia. More evaluative studies in this field may provide criteria to focus future regulations and other preventive interventions.