Monospecific helminth and arthropod infections in an urban population of brown rats from Doha, Qatar

Occurrence of Hymenolepis diminuta: a potential helminth of zoonotic importance in murid rodents

The study reveals the prevalence of a potential rodent-borne zoonotic helminth species, Hymenolepis diminuta in commensal rodents caught from irrigated and rain-fed areas of Swat, Pakistan. Three hundred and fifty rodents (269 rats and 81 mice) trapped during vegetative, flowering/fruiting and mature/harvesting stages of crops were studied from 2011-2013. Hymenolepisdiminuta eggs were identified on the basis of their shape, size, colour and markings on the surface of the egg shell and three pairs of embryonic hook-lets. Overall prevalence of H. diminuta was 3.14% (n=11/350). The highest prevalence 3.49% (n=5/143) of H. diminuta was noted at harvesting stages of the crops whereas the lowest 2.59% (n=2/77) during vegetative stage. Infection was higher in males 3.25% (n=7/215) than females 2.96% (n=4/135). Adult rodents were highly infected while no sub-adult was found infected. Infection was higher in mice 3.70% (3/81) than rats 2.69% (8/269) while no significance (p=1.0000:0.1250 to 32.00 CI). Rats and mice appears to show the most suitable reservoirs by hosting H. diminuta a zoonotic helminth. The presence of these rodents in all possible habitats can act as a main channel of transferring parasites through various habitats and can pose a hazard to humans in the area.

Morphometric Study of Mus musculus, Rattus norvegicus, and Rattus rattus in Qatar

Simple Summary

Rodents are the most abundant and diversified group of mammals. These animals show genetic and physical diversity in different ecosystems of the world, including the desert ecosystem. The current study was undertaken to check the morphometric pattern of three commensal rodent species, viz, Mus musculus, Rattus norvegicus, and Rattus rattus, in Qatar. One hundred forty-eight rodents were captured and studied for body and cranio-mandibular measurements. The study found R. norvregicus as the most prevalent rodent in Qatar. Most of the rodents were collected from Al Rayan municipality, were adults, and were from livestock farms. The rodents’ average body weights were 18.8 ± 2.2 gm, 264.3 ± 87.5 gm, and 130 ± 71.3 gm for M. musculus, R. norvegicus, and R. rattus, respectively. The average morphometric measurements of the external body and skull were normally distributed and can be used as a reference of R. norvegicus and R. rattus for Qatar.

Abstract

The current study was undertaken to estimate the morphometric pattern of three commensal rodents, i.e., Mus musculus, Rattus norvegicus, and Rattus rattus in Qatar. One hundred forty-eight rodents were captured from different facilities throughout Qatar. The captured rodents were used to identify the external body and cranio-mandibular morphometry. The study found that R. norvregicus was the most prevalent (n = 120, 81%, 95% CI: 73.83–87.05). Most of the rodents were collected from Al Rayan municipality (n = 92, 62%), were adults (n = 138, 93.2%, 95% CI: 87.92–96.71), and were from livestock farms (n = 79, 49%, 95% CI: 41.02–57.65). The rodents’ average body weights were 18.8 ± 2.2 gm, 264.3 ± 87.5 gm, and 130 ± 71.3 gm for M. musculus, R. norvegicus, and R. rattus, respectively. The research found that the studied rodents are smaller than those of other countries such as Turkey, Tunisia, and Iran. The study of morphometry is a useful tool for the traditional identification of small mammal species, including rodents. The average morphometric measurements of the external body and skull were normally distributed and can be used as a reference of R. norvegicus and R. rattus for Qatar. A further comprehensive study is required to investigate the rodent population index, eco-friendly control program, and public health importance in Qatar.

Rodent-Related Zoonotic Pathogens at the Human-Animal-Environment Interface in Qatar: A Systematic Review and Meta-Analysis

Rodents are one of the most diversified terrestrial mammals, and they perform several beneficial activities in nature. These animals are also important as carriers of many pathogens with public health importance. The current systematic review was conducted to formulate a true depiction of rodent-related zoonoses in Qatar. Following systematic searches on PubMed, Scopus, Science Direct, and Web of Science and a screening process, a total of 94 published articles were selected and studied. The studied articles reported 23 rodent-related zoonotic pathogens that include nine bacterial, eleven parasitic, and three viral pathogens, from which the frequently reported pathogens were Mycobacterium tuberculosis (32 reports), Escherichia coli (23), and Salmonella spp. (16). The possible pathway of entry of the rodent-borne pathogens can be the land port, seaports, and airport of Qatar through carrier humans and animals, contaminated food, and agricultural products. The pathogens can be conserved internally by rodents, pets, and livestock; by agricultural production systems; and by food marketing chains. The overall estimated pooled prevalence of the pathogens among the human population was 4.27% (95%CI: 4.03–4.51%; p < 0.001) with significant heterogeneity (I² = 99.50%). The top three highest prevalent pathogens were M.tuberculosis (30.90%; 22.75–39.04%; p < 0.001; I² = 99.70%) followed by Toxoplasma gondii (21.93%; 6.23–37.61%; p < 0.001; I² = 99.30%) and hepatitis E virus (18.29%; 11.72–24.86%; p < 0.001; I² = 96.70%). However, there is a knowledge gap about the listed pathogens regarding the occurrence, transmission pathways, and rodent role in transmission dynamics at the human–animal–environment interface in Qatar. Further studies are required to explore the role of rodents in spreading zoonotic pathogens through the One Health framework, consisting of zoologists, ecologists, microbiologists, entomologists, veterinarians, and public health experts in this country.

The pests of a pest: A systematic review of ectoparasitic fauna among synanthropic rodents in the 21st century with meta-analysis

Synanthropic rodents are important urban pests that frequently carry hematophagous ectoparasites. These blood-sucking pests are capable of transmitting epizootic and zoonotic pathogens by landing on one host after feeding on an infected animal. This study aimed to estimate the prevalence of ectoparasites carried by synanthropic rodents and discuss the pathogens that are associated with these external parasites. We searched relevant literatures using predefined criteria in the following databases: EMBASE, PUBMED, Web of Science and Scopus from January 2000 to June 2020. Quality of studies was evaluated using Newcastle-Ottawa scale (NOS). Of 35 included studies from 15 countries in Africa, America, Asia, Europe and Oceania, black rats (R. rattus), brown rats (R. norvegicus), pacific rats (R. exulans) and house mice (Mus musculus) were common synanthropic rodents. Mites (Mesostigmata, Sarcoptiformes and Trombidiformes) were the most prevalent (42.6%, 95% CI 26-59.2), followed by ticks (Ixodida) (21.5%, 95% CI 10.5-32.6), lice (Phthiraptera) (17.8%, 95% CI 7.7-27.9) and fleas (Siphonaptera) (14.1%, 95% CI 10.1-18.1). Heterogeneity (I2>96%) across studies was statistically significant. The ectoparasitic fauna was shared considerably by different urban rodent species and appeared to be more diverse in R. rattus and R. norvegicus. Nonetheless, pathogens carried by these ectoparasites were rarely investigated. In conclusion, ectoparasites are ubiquitous in urban-dwelling rodents but our understanding of the epidemiology and the associated pathogens of these parasites remains limited. Further studies are warranted to unravel the pathogen landscape found in rodent-associated ectoparasites.

Rodent Ectoparasites in the Middle East: A Systematic Review and Meta-Analysis

Rodents carry many ectoparasites, such as ticks, lice, fleas, and mites, which have potential public health importance. Middle Eastern countries are hotspots for many emerging and re-emerging infectious diseases, such as plague, leishmaniasis, Crimean Congo hemorrhagic fever, and Q fever, due to their ecological, socioeconomic, and political diversity. Rodent ectoparasites can act as vectors for many of these pathogens. Knowledge of rodent ectoparasites is of prime importance in controlling rodent ectoparasite-borne zoonotic diseases in this region. The current systematic review and meta-analysis performs a comprehensive synthesis of the available knowledge, providing an evidence-based overview of the ectoparasites detected on rodents in Middle Eastern countries. Following a systematic search in Pubmed, Scopus, and Web of Science, a total of 113 published articles on rodent ectoparasites were studied and analyzed. A total of 87 rodent species were documented, from which Mus musculus, Rattus norvegicus, and Rattus rattus were found to be the most common. Fleas were the most reported ectoparasites (87 articles), followed by mites (53), ticks (44), and lice (25). Xenopsylla cheopis, Polyplax spinulosa, Ornithonyssus bacoti, and Hyalomma rhipicephaloides were the most commonly described fleas, lice, mites, and ticks, respectively. Based on the reviewed articles, the median flea, louse, mite, and tick indices were highest in Israel (4.15), Egypt (1.39), Egypt (1.27), and Saudi Arabia (1.17), respectively. Quantitative meta-analysis, using a random-effects model, determined the overall pooled flea prevalence in the Middle East as 40% (95% CI: 25-55, I2 = 100%, p < 0.00001), ranging between 13% (95% CI: 0-30, I2 = 95%, p < 0.00001) in Iran and 59% (95% CI: 42-77, I2 = 75%, p < 0.00001) in Israel. The overall pooled louse prevalence was found to be 30% (95% CI: 13-47, I2 = 100%, p < 0.00001), ranging between 25% in Iran (95% CI: 1-50, I2 = 99%) and 38% in Egypt (95% CI: 7-68, I2 = 100%). In the case of mites, the pooled prevalence in this region was 33% (95% CI: 11-55, I2 = 100%, p < 0.00001), where the country-specific prevalence estimates were 30% in Iran (95% CI: 4-56, I2 = 99%) and 32% in Egypt (95% CI: 0-76, I2 = 100%). For ticks, the overall prevalence was found to be 25% (95% CI: 2-47, I2 = 100%, p < 0.00001), ranging from 16% in Iran (95% CI: 7-25, I2 = 74%) to 42% in Egypt (95% CI: 1-85, I2 = 100%). The control of rodent ectoparasites should be considered to reduce their adverse effects. Using the One Health strategy, rodent control, and precisely control of the most common rodent species, i.e., Mus musculus, Rattus norvegicus, and Rattus rattus, should be considered to control the rodent-borne ectoparasites in this region.

Helminth Parasites among Rodents in the Middle East Countries: A Systematic Review and Meta-Analysis

Rodents can be a source of zoonotic helminths in the Middle East and also in other parts of the world. The current systematic review aimed to provide baseline data on rodent helminths to recognize the threats of helminth parasites on public health in the Middle East region. Following a systematic search on PubMed, Scopus, and Web of Science, a total of 65 research studies on rodent cestodes, nematodes, and trematodes, which were conducted in the countries of the Middle East, were analyzed. The study identified 44 rodent species from which Mus musculus, Rattus norvegicus, and Rattus rattus were most common (63%) and recognized as the primary rodent hosts for helminth infestation in this region. Cestodes were the most frequently reported (n = 50), followed by nematodes (49), and trematodes (14). The random effect meta-analysis showed that the pooled prevalence of cestode (57.66%, 95%CI: 34.63-80.70, l2% = 85.6, p < 0.001) was higher in Saudi Arabia, followed by nematode (56.24%, 95%CI: 11.40-101.1, l2% = 96.7, p < 0.001) in Turkey, and trematode (15.83%, 95%CI: 6.25-25.1, l2% = 98.5, p < 0.001) in Egypt. According to the overall prevalence estimates of individual studies, nematodes were higher (32.71%, 95%CI: 24.89-40.54, l2% = 98.6, p < 0.001) followed by cestodes (24.88%, 95%CI: 19.99-29.77, l2% = 94.9, p < 0.001) and trematodes (10.17%, 95%CI: 6.7-13.65, l2% = 98.3, p < 0.001) in the rodents of the Middle East countries. The review detected 22 species of helminths, which have zoonotic importance. The most frequent helminths were Capillaria hepatica, Hymenolepis diminuta, Hymenolepis nana, and Cysticercus fasciolaris. There was no report of rodent-helminths from Bahrain, Jordan, Lebanon, Oman, United Arab Emirates, and Yemen. Furthermore, there is an information gap on rodent helminths at the humans-animal interface level in Middle East countries. Through the One Health approach and countrywide detailed studies on rodent-related helminths along with their impact on public health, the rodent control program should be conducted in this region.

Helminth infections of the brown rat (Rattus norvegicus Berkenhout, 1769) in the biocenoses of South-West Belarus

The result of helminthological examination of 20 brown rats from various biocenoses of South-West Belarus during 1996-2011 is presented. Twelve animals were infected. Six species of helminths were found: 1 trematode species, 3 cestode species and 2 nematode species. The most often, the brown rat infected with mesocercariae of trematode Alaria alata (Goeze, 1782). The helminth fauna of brown rats living in the biocenoses are specified for the first time in Belarus.

Biotic and abiotic effects on the intestinal helminth community of the brown rat Rattus norvegicus from Rio de Janeiro, Brazil

Rattus norvegicus has attracted much attention because of its role as a reservoir of zoonotic pathogens. This work aimed to identify the intestinal helminth species in R. norvegicus and to analyse the effects of temperature, rainfall, host age and sex on the helminth community structure. Moreover, this study investigated the possible associations among helminth species in an urban population of R. norvegicus in São Gonçalo, Rio de Janeiro, sampled during the rainy and dry seasons over a span of 2 years. A total of 112 rats were infected by six species of helminths. The nematode Nippostrongylus brasiliensis was the most prevalent and abundant species, with high mean intensity in both seasons, followed by Strongyloides venezuelensis, Heterakis spumosa, Raillietina sp., Hymenolepis nana and Moniliformis moniliformis. Co-occurrence was found between N. brasiliensis and S. venezuelensis and between N. brasiliensis and H. spumosa. The occurrence of S. venezuelensis was related to rainfall. The understanding of the helminth community structure in this synanthropic rat provides basic information on parasites of public health importance, as two helminth species (H. nana and M. moniliformis) recovered from rats in the urban area studied can infect humans.

Occurrence of ectoparasitic arthropods associated with rodents in Hail region northern Saudi Arabia

Ectoparasitic arthropods are a diverse element of the Saudi fauna. Due to this, a survey of ectoparasites associated with rodents was conducted as a preliminary study in five districts of Hail region of northern Saudi Arabia for the first time. Ectoparasites extracted from 750 rodents were sampled and identified by recording their frequency of appearance. Results revealed that 1,287 ectoparasites infested 316 of the captured rodent hosts. These ectoparasites parasitized on four species of rodents including three species of rats Rattus rattus rattus, Rattus rattus frugivorus, and Rattus rattus alexandrinus and one species of mouse Acomys dimidiatus (Rodentia: Muridae). The ectoparasites belong to four different groups: ticks, fleas, lice, and mites. Ticks were the highest in the number, while fleas were the lowest among all the extracted ectoparasite groups. The collected ectoparasitic arthropods consisted of seven species. Ticks were of two species: Rhipicephalus turanicus and Rhipicephalus sanguineus (Acari: Ixodidae), fleas were of two species: Xenopsylla cheopis and Xenopsyllus conformis mycerini (Siphonaptera: Pulicidae), lice was a single species: Polyplax serrata (Anoplura: Hoplopleuridae), and mites were of two species: Laelaps nuttali and Laelaps echidninus (Mesostigmata: Laelapidae). The findings of the study showed that the intensity of infestation was varied between rodent host sexes, wherein females had the highest rate of parasitic infestation, and the parasitic index of appearance was very high for one group of parasites (i.e., ticks). The parasitic prevalence was 42.13 % on rodents, and mites were the most prevalent parasite species. Overall, this study was carried out to establish baseline data for ectoparasite-infested rodents in Hail region, Saudi Arabia, and may help for appropriate planning to control zoonotic diseases in this area.

A longitudinal study of Angiostrongylus cantonensis in an urban population of Rattus norvegicus in Brazil: the influences of seasonality and host features on the pattern of infection

BACKGROUND

The nematode Angiostrongylus cantonensis is a zoonotic parasite and the most important cause of eosinophilic meningitis worldwide in humans. In Brazil, this disease has been reported in the states of Espírito Santo and Pernambuco. The parasite has been detected in the naturally infected intermediate host, in the states of Rio de Janeiro, Pernambuco and Santa Catarina. The murid Rattus norvegicus R. rattus were recently reported to be naturally infected in Brazil. In this study, we conducted a two-year investigation of the dissemination pattern of A. cantonensis in R. norvegicus in an urban area of Rio de Janeiro state, Brazil, and examined the influence of seasonality, year, host weight and host gender on parasitological parameters of A. cantonensis in rats.

METHODS

The study was conducted in an area of Trindade, São Gonçalo municipality, Rio de Janeiro, Brazil. Prevalence of infected rats, intensity and abundance of A. cantonensis were calculated, and generalized linear models were created and compared to verify the contribution of host gender, host weight, year and seasonality to the variations in A. cantonensis abundance and prevalence in rats.

RESULTS

The prevalence of A. cantonensis infection was stable during the rainy (71%, CI 58.9- 81.6) and dry seasons (71%, CI 57.9-80.8) and was higher in older rats and in females. Seasonality, host weight (used as a proxy of animal age) and gender were all contributing factors to variation in parasite abundance, with females and heavier (older) animals showing larger abundance of parasites, and extreme values of parasite abundance being more frequent in the dry season.

CONCLUSIONS

The high prevalence of this parasite throughout the study suggests that its transmission is stable and that conditions are adequate for the spread of the parasite to previously unaffected areas. Dispersion of the parasite to new areas may be mediated by males that tend to have larger dispersal ability, while females may be more important for maintaining the parasite on a local scale due to their higher prevalence and abundance of infection. A multidisciplinary approach considering the ecological distribution of the rats and intermediate hosts, as well as environmental features is required to further understand the dynamics of angiostrongyliasis.

Helminth communities from two urban rat populations in Kuala Lumpur, Malaysia

BACKGROUND

The prevalence of parasitic infections among commensal animals such as black and brown rats in many tropical countries is high and in comparison with studies on rodents in temperate climates, little is known about the community structure of their parasites. Rodent borne parasites pose threats to human health since people living in close proximity to rodent populations can be exposed to infection.

METHODS

The helminth community structures of two urban rat populations in Kuala Lumpur, Malaysia were investigated. The rats were from two contrasting sites in the city caught over a period of 21 months in 2000-2002.

RESULTS

Eleven species of helminth parasites comprising seven nematodes (Heterakis spumosum, Mastophorus muris, Nippostrongylus brasiliensis, Syphacia muris, Pterygodermatites tani/whartoni, Gongylonema neoplasticum, Angiostrongylus malaysiensis), three cestodes (Hymenolepis (Rodentolepis) nana, H. diminuta and Taenia taeniaeformis) and one acanthocephalan (Moniliformis moniliformis) were recovered from 346 Rattus rattus and 104 R. norvegicus from two urban sites, Bangsar and Chow Kit, during 2000-2002. Rattus rattus harboured over 60% of all helminths compared with R. norvegicus, although both host species played a dominant role in the different sites with, for example R. norvegicus at Bangsar and R. rattus at Chow Kit accounting for most of the nematodes. Overall 80% of rats carried at least one species of helminth, with the highest prevalences being shown by H. diminuta (35%), H. spumosum (29.8%) and H. nana (28.4%). Nevertheless, there were marked differences in prevalence rates between sites and hosts. The influence of extrinsic (year, season and site) and intrinsic (species, sex and age) factors affecting infracommunity structure (abundance and prevalence of infection) and measures of component community structure were analyzed.

CONCLUSIONS

Since at least two species of rat borne helminths in Kuala Lumpur have the potential to infect humans, and these showed high prevalences in the rats, the assessment and regular monitoring of infections carried by wild rodents have important roles to play in public health.

Intestinal helminths of feral cat populations from urban and suburban districts of Qatar

A survey of the helminths of 658 adult cats from feral urban and suburban populations in Qatar was conducted across all months in 2006 and 2007. Six species of helminths were identified, comprising two cestodes (Taenia taeniaeformis [73.6%] and Diplopylidium acanthotetra [47.1%]) and four nematodes (Ancylostoma tubaeforme [14.7%], Physaloptera praeputialis [5.2%], Toxocara cati [0.8%] and Toxascaris leonina [0.2%]), and 83% of cats were infected with at least one of these. The average number of species harboured was 1.4 and the average worm burden was 55.8 worms/cat. The vast majority of worms (97.6%) were cestodes, nematodes being relatively rare. Prevalence and abundance of infections were analyzed, taking into consideration four factors: year (2006 and 2007), site (urban and suburban), season (winter and summer) and sex of the host. Analyses revealed marked year effects, female host bias in some species and interactions involving combination of factors, but especially sex and season of the year. The results indicate that whilst the majority of adult feral cats in Qatar carry helminth infections, infections are variable between years and subject to annual changes that may reflect climatic and other environmental changes in the rapidly developing city of Doha and its suburban surroundings. Only two species have the potential to infect humans and both were rare among the sampled cats (A. tubaeforme and T. cati).

Patterns of parasitic infections in faecal samples from stray cat populations in Qatar

The parasite fauna of stray cat populations, comprising mainly helminth parasites, is described for the first time from the arid environment of the Qatar peninsula. During the winter and summer months of 2005, 824 faecal samples were examined from six sites in Qatar. Up to seven species of parasites were identified, six of which were nematodes - Strongyloides stercoralis as the most prevalent (18.4%), followed by Aelurostrongylus abstrusus (7.5%), Toxocara cati (6.1%), Ancylostoma tubaeforme (5.9%) and Physaloptera sp. (4.8%) and Toxascaris leonina (0.7%) - and one sporozoan species, Isospora felis (0.5%). Unidentified cestode eggs were also recovered from 10.7% of samples examined. The parasite species were found to be highly overdispersed in faecal samples from all sites, whereas the prevalence and intensity of infections were influenced by site and season. Infection levels tended to be higher during the winter season, especially in the case of A. abstrusus and A. tubaeforme, when conditions of temperature and humidity were more favourable for the development of egg and/or larval stages of parasites compared with the extremely hot and dry summer months. The results are discussed in relation to the distribution of the cat population in the vicinity of Doha and its outskirts and the potential threat of parasite transmission to human communities in Qatar.

Descriptive epidemiology of intestinal helminth parasites from stray cat populations in Qatar

A total of 488 stray cats, 212 adult and 29 juvenile females plus 235 adult and 12 juvenile males, were examined post-mortem during the winter and summer months of 2006 from five sites in the vicinity of Doha and its outskirts. Five helminths, comprising three nematode and two cestode species were identified and the majority of cats harboured two of these species. The most prevalent was the cestode Taenia taeniaeformis (75.8%), followed by the cestode Diplopylidium sp. (42.8%), and the nematodes Ancylostoma tubaeforme (17.0%), Physaloptera sp. (6.6%) and Toxocara cati (0.8%). All five species were found to be typically overdispersed in their distribution. Using univariate and multivariate analyses, the prevalence and abundance of infections were primarily influenced by host gender and season, with females tending to harbour higher levels of infection during the summer. No significant differences were found relative to site except in the case of Physaloptera sp. Using bivariate Pearson product moment correlations, significant positive co-occurrences were identified between Diplopylidium sp. and T. taeniaeformis and also between A. tubaeforme and T. taeniaeformis. The results are discussed in relation to the effect of environmental conditions on the intestinal helminth infracommunities and their possible interactions in stray cat populations from such a harsh and arid region as Qatar.

Parasite populations in the brown ratRattus norvegicusfrom Doha, Qatar between years: the effect of host age, sex and density

A total of 179 urban rats were sampled in the city of Doha in Qatar across the winter seasons (February–April) of 2002 and 2003. Only two parasites were identified, with overall prevalences of 35.8% and 41.3% for the cestodeHymenolepis diminutaand the fleaXenopsylla astiarespectively. The prevalence ofH. diminutawas markedly influenced by both year of study and host age, being higher in 2003 and amongst older rats. The abundance of infection ofH. diminutawas influenced by the year of study, host age and sex. Worm burdens in adult rats were almost twice as heavy in males compared with females and adults of both sexes harboured heavier infections than juveniles. The prevalence ofX. astiawas influenced by both year and host age, being higher in juvenile rats in 2002 and in adults in 2003. The abundance ofX. astiawas significantly higher in 2003 and both male and female rats showed similar abundances, but in 2003 females were more heavily infested. Reasons for this are discussed in relation to the differing foraging strategies shown by male and female rats. The prevalence and abundance profiles for bothH. diminutaandX. astiawere higher overall in 2003 due to a significant increase in the rat population density, although this did not reflect in any increase in parasite species richness. Rats that were infected withH. diminutawere almost twice as likely to be infected withX. astiathan those without the cestode, but when controlled for the effects of year, host age and sex, no quantitative interactions were detected between the two parasite species.

Variation in the helminth community structure in spiny mice (Acomys dimidiatus) from four montane wadis in the St Katherine region of the Sinai Peninsula in Egypt

We compared helminth communities in spiny mice (Acomys dimidiatus) from 4 wadis in the arid montane region of the southern Sinai in Egypt, in a 4-week period in late summer. Total helminth species richness was 14 (8 nematodes, 5 cestodes and 1 acanthocephalan) with 94% of mice carrying at least 1 species and an overall mean species richness of 1·85. The most prevalent parasites wereProtospirura muricola(47·8%) andDentostomella kuntzi(46·3%). One larval cestode,Joyeuxiella rossicum, represents a new host record. The helminth community was dominated by intestinal nematodes (88·7%) of which 58·2% were arthropod-transmitted heteroxenic species. At the component community level, 70% of the worms were recovered from mice in just two wadis (Gharaba and Tlah) and 48·6% of intestinal nematodes were from Wadi Gharaba. Although only 7 species of helminths were recorded from Wadi Gharaba, this site gave the highest Berger-Parker dominance index because ofP. muricola. P. muricolawas also dominant in Wadi El Arbaein whilstSyphacia minutawas the dominant species in Wadis Gebal and Tlah. At the infracommunity level, mean species richness and Brillouin's index of diversity were highest in Wadi Tlah and lowest in Wadi Gebal, and the former was age dependent. Whilst mice from different wadis differed in the nematodes that were most common, those from Wadi Gharaba carried the highest mean number of worms/mouse. The abundance ofP. muricolain particular varied markedly between sites: Wadi Gharaba was distinct as the site showing the highest mean worm burden whereas mice from Wadi Gebal were uninfected. None of the directly transmitted oxyuroid nematodes showed significant variation in abundance between wadis, or host sex or age classes. Overall, the single extrinsic factor in the study, site of capture, was more important than the intrinsic factors in explaining variation in helminth communities in the region. We conclude that in the high mountains of southern Sinai, each wadi is distinct in terms of its rodent parasites, and hence we expect spatially different coevolutionary pressures on their hosts, with resultant variation in life-histories.