Biological, seasonal and environmental factors associated with Pulex irritans infestation of dairy goats in Greece

The objectives of the present study were to study the fauna of fleas infesting dairy goats in Greece, the spectrum of hosts each flea species infests, identify risk factors in the environment, and goat management practices that favour flea infestation of goats, and describe the seasonal variation of infestation in goats. For this purpose, a total of 64 herds, with a history of flea infestation in goats, were visited during June and July of 2002 for data collection on flea burdens, species of fleas on goats, and other farm or pet animal species in the farm. Also data were collected on herd characteristics and management along with the flea infestation status of the village where it was located through a questionnaire survey. Data on elevation and climatic characteristics of the villages where the herds were located were also used in the study. All fleas collected from goats, sheep, pigs, and cattle were identified as being Pulex irritans. All fleas collected from cats were identified as being Ctenocephalides felis. Dogs were infested either with P. irritans, C. canis, or C. felis, or with both C. canis and C. felis. Kids had a significantly higher flea burden than goats and the Skopelos breed had the highest flea burden of all breeds followed in diminishing order by the breeds Capra prisca, Saanen cross mix, and Alpine cross mix (p < 0.05). The gender of the animal had no significant effect on flea burden. Factors significantly affecting the flea burden of goats were duration of flea infestation in the herd, type of flea control, and manure imported prior to the appearance of fleas in the herd (p < 0.05). The flea burden of goats was highest during summer and lowest during winter (p < 0.01), with complete an absence of infestation in January and February. Finally, a significant difference (p < 0.05) was found between the average annual temperature of villages with flea infestation (15.59 degrees C) and villages without flea infestation (17.14 degrees C). It was concluded that P. irritans was a true infestation of goats in Greece.

Qualitative and quantitative observations on the flea population dynamics of dogs and cats in several areas of Germany

From an ongoing country-wide study on the spectrum, the epidemiology and the population dynamics of flea infestations in dogs and cats, important preliminary results from the three areas of Karlsruhe, Nuernberg and Leipzig are presented. A total of 1922 dogs and 1838 cats from 12 different veterinary practices or clinics in three areas of Germany were systematically examined between July 2003 and June 2004. All dogs and cats appearing for a clinical veterinary consultation on one regular working day per month, per practice, were clinically examined. Dogs and cats were examined irrespective of any kind of prior therapeutic or prophylactic insecticidal treatment. The results show that a total of 99 dogs (5.13%) and 263 cats (14.33%) were infested. Cats were more often flea-infested than dogs (p < 0.05). The highest infestation rates for dogs (x = 7.87%) were detected between July and October, and for cats (x = 21.14%) between July and September, the lowest infestation rates for dogs (x = 2.88%) were observed between November and May, and for cats (x = 12.16%) between November and April (p < 0.05). Although the prevalences were generally higher during the summer months, no statistical differences were detectable when looking at the pattern between the four seasons, neither for dogs, nor for cats. Interestingly, the highest prevalences in dogs (9.9%) were detected in June 2004 and comparatively, in cats (23.86%) in August. The lowest detection rates in dogs were seen (1.28%) in April and in cats (7.26%) in January. The preliminary results did not indicate any tendency for a relationship between climatic conditions and flea infestation rates. Similarly, no differences of the infestations rates were detectable between urban and rural areas, 56% (dogs) and 46% (cats) of the infested pets originated from urban habitats. The flea species collected include Ctenocephalides felis, Ctenocephalides canis, Archaeopsylla erinacei, Pulex irritans, Ceratophyllus gallinae, etc. The overall frequencies reveal that C. felis was the most prominent species (81.5%), followed by C. canis (12.5%), A. erinacei (2.7%) and P. irritans (1.7%).

Possible Vector Dissemination by Swift Foxes following a Plague Epizootic in Black-tailed Prairie Dogs in Northwestern Texas

To determine whether swift foxes (Vulpes velox) could facilitate transmission of Yersinia pestis to uninfected black-tailed prairie dog (Cynomys ludovicianus) colonies by acquiring infected fleas, ectoparasite and serologic samples were collected from swift foxes living adjacent to prairie dog towns during a 2004 plague epizootic in northwestern Texas, USA. A previous study (1999-2001) indicated that these swift foxes were infested almost exclusively with the flea Pulex irritans. Black-tailed prairie dogs examined from the study area harbored only Pulex simulans and Oropsylla hirsuta. Although P. irritans was most common, P. simulans and O. hirsuta were collected from six swift foxes and a single coyote (Canis latrans) following the plague epizootic. Thus, both of these canids could act as transport hosts (at least temporarily) of prairie dog fleas following the loss of their normal hosts during a plague die-off. All six adult swift foxes tested positive for antibodies to Y. pestis. All 107 fleas from swift foxes tested negative for Y. pestis by mouse inoculation. Although swift foxes could potentially carry Y. pestis to un-infected prairie dog colonies, we believe they play only a minor role in plague epidemiology, considering that they harbored just a few uninfected prairie dog fleas (P. simulans and O. hirsuta).

High exposure to Tunga penetrans (Linnaeus, 1758) correlates with intensity of infestation

Tungiasis is a parasitic skin disease widespread in resource-poor urban and rural communities in Brazil. Inhabitants of an urban slum in Northeast Brazil were examined for the presence of tungiasis lesions and followed-up twice a week for a period of three weeks. Each time the number, stages, and topographic localization of lesions were recorded on a documentation sheet. The infestation rate (number of newly embedded sand fleas per individual and day) remained stable during the observation period. The infestation rate was significantly related to the intensity of infestation (total number of lesions present) (rho = 0.70, p < 0.0001) and the proportion of viable lesions (rho = 0.28, p < 0.0001). The results indicate that in an endemic area the infestation intensity and the proportion of viable lesions can be used as a proxy to assess the exposure of individuals at risk for tungiasis. Persistently high infestation rates during the transmission season favour the use of prevention measures against invading sand fleas (such as a repellent) rather than a drug to kill already embedded parasites.

Epidemic trichodinosis associated with severe epidermal hyperplasia in largemouth bass, Micropterus salmoides, from North Carolina, USA

An epidemic of trichodinosis associated with severe epidermal hyperplasia occurred in adult largemouth bass (Micropterus salmoides) from the Chowan River drainage, North Carolina (USA) in late winter to early spring 2002. Initial reports by anglers of fish with a "jelly-like slime coat" on the skin prompted an electrofishing survey in which about 10% of sampled largemouth bass had a very thick, bluish-white "mucoid layer" on the body and fins. Moderate to heavy infestations of the ciliate Trichodina were detected in wet mounts of skin from five of five fish having the mucoid layer; these fish also had significant gill infestations. An additional two fish with only mild reddening and four asymptomatic fish (no skin lesions) had mild skin infestations but no gill infestations. Two asymptomatic fish had no skin parasites. Four fish with the mucoid layer were necropsied and had extremely severe epidermal hyperplasia on the body and fins. The hyperplasic epidermis had relatively few mucus cells and typically was about 5-10 times thicker than healthy epidermis. The upper four fifths of the epidermis consisted of finely vacuolated, highly flattened, somewhat disorganized epithelial cells. No other significant clinical or histopathologic abnormalities were detected. No systemic infection by pathogenic bacteria was noted. The environmental cause of the epidemic is uncertain but the lesions suggest that some chronic stressor was involved.

Tungiasis in rural Haiti: a community-based response

Tungiasis is a disease endemic to poor communities in Latin America, the Caribbean and Africa. It is caused by the female flea, Tunga penetrans, which burrows into the skin of its host to feed while producing and extruding eggs. Consequent lesions may be painful and even crippling with damage ranging from mild erythema and swelling to necrosis. Superinfection of lesions can be serious and may result in auto-amputation or death from tetanus. We describe an outbreak of tungiasis in rural Haiti and a community-based intervention used to address it. Of 177 patients assessed, 132 (47 female, 85 male, 23 children) had tungiasis lesions. Forty-four patients had clinical signs of superinfection; 15 had ectopic lesions. Community health workers cleaned and disinfected patients' feet and any parts of the body with ectopic lesions, and then extracted fleas from existing lesions. Patients with superinfections were treated with appropriate antibiotics. Over 1000 pairs of shoes were distributed in the villages. Over 400 adults were given tetanus vaccinations during follow-up visits. Patients who had been treated reported feeling better and those who had received shoes indicated they had not developed new lesions. All superinfections were resolved. We concluded that community-based care can treat tungiasis effectively.

The epidemiology, diagnosis, management, and prevention of ectoparasitic diseases in travelers

Ectoparasitic diseases have been reported in travelers returning from both developed and developing nations.(1-3) Ectoparasitic diseases afflict the skin and its appendages and orifices, especially the scalp, facial, and pubic hairs; external ears; nares; orbits and eyelids; and genitourinary and rectal orifices. Like endoparasites, ectoparasites may be either obligatory parasites, which need to feed on human hosts to complete their life cycles, or facultative parasites, which prefer to feed on nonhuman hosts and infest humans only as accidental or dead-end hosts.(4,5).

A faunal survey of streblid flies (Diptera: Streblidae) associated with bats in Paraguay

An extensive survey of the ectoparasites infesting bats in Paraguay provides information regarding the taxonomy and host distribution of streblid bat flies at a geographic interface between subtropical and temperate habitats. Five families of bats representing 45 species, including Molossidae (5 genera and 15 species), Natalidae (1 genus and 1 species), Phyllostomidae (11 genera and 15 species), Noctilionidae (1 genus and 2 species), and Vespertilionidae (4 genera and 12 species) were collected from 24 localities across Paraguay and sampled for ectoparasites. In total, 2,467 bat flies were collected, representing 11 genera and 31 nominal species of Streblidae, of which 6 genera and 24 species are new records for Paraguay. No streblids were collected from vespertilionid bats; 23 species infested phyllostomids, 6 species noctilionids, 1 species a natalid, and 1 species molossids. Streblid bat flies were highly specific to certain host groups and individual host species, and their geographic distributions closely followed those of their host bats. Of 31 streblid species surveyed, 27 were monoxenous (i.e., associated with a single host species), and 4 were stenoxenous (i.e., associated with a group of phylogenetically related hosts). The number of streblid species is greatly reduced in the Chaco region west of the Paraguay River, largely because of the lack of phyllostomid host bats.

No Evidence of Persistent Yersina pestis Infection at Prairie Dog Colonies in North-Central Montana

Sylvatic plague is a flea-borne zoonotic disease caused by the bacterium Yersinia pestis, which can cause extensive mortality among prairie dogs (Cynomys) in western North America. It is unclear whether the plague organism persists locally among resistant host species or elsewhere following epizootics. From June to August 2002 and 2003 we collected blood and flea samples from small mammals at prairie dog colonies with a history of plague, at prairie dog colonies with no history of plague, and from off-colony sites where plague history was unknown. Blood was screened for antibody to Y. pestis by means of enzyme-linked immunosorbent assay or passive hemagglutination assay and fleas were screened for Y. pestis DNA by polymerase chain reaction. All material was negative for Y. pestis including 156 blood samples and 553 fleas from colonies with a known history of plague. This and other studies provide evidence that Y. pestis may not persist at prairie dog colonies following an epizootic.

A PLAGUE EPIZOOTIC IN THE BLACK-TAILED PRAIRIE DOG (CYNOMYS LUDOVICIANUS)

Plague is the primary cause for the rangewide decline in prairie dog (Cynomys spp.) distribution and abundance, yet our knowledge of plague dynamics in prairie dog populations is limited. Our understanding of the effects of plague on the most widespread species, the black-tailed prairie dog (C. ludovicianus), is particularly weak. During a study on the population biology of black-tailed prairie dogs in Wyoming, USA, plague was detected in a colony under intensive monitoring, providing a unique opportunity to quantify various consequences of plague. The epizootic reduced juvenile abundance by 96% and adult abundance by 95%. Of the survivors, eight of nine adults and one of eight juveniles developed antibodies to Yersinia pestis. Demographic groups appeared equally susceptible to infection, and age structure was unaffected. Survivors occupied three small coteries and exhibited improved body condition, but increased flea infestation compared to a neighboring, uninfected colony. Black-tailed prairie dogs are capable of surviving a plague epizootic and reorganizing into apparently functional coteries. Surviving prairie dogs may be critical in the repopulation of plague-decimated colonies and, ultimately, the evolution of plague resistance.

METAZOAN PARASITE COMMUNITIES OF SENTINEL BLUEGILL CAGED IN TWO URBANIZING STREAMS, SAN ANTONIO, TEXAS

Urbanization has deleterious effects on water quality and biota in stream systems. This project used caged bluegill (Lepomis macrochirus) to assess metazoan fish parasite communities in 2 urbanizing streams of the upper San Antonio River Basin, Bexar County, Texas. Field studies on Leon and Salado creeks were conducted during late summer in 1999 and 2000. Juvenile bluegill, obtained from a local aquaculturist, were held in cages for 10-22 days at middle and lower watershed sites to expose them to in-stream conditions and to allow parasite communities to establish. After removal from cages, fish were examined for metazoan parasites. In 2000, wild Lepomis spp. also were collected at study sites for parasite assessment. In both years, physical and chemical water properties were monitored at each site. Of the 120 fish examined for parasites, 96.7% were infected by at least 1 organism from among the 11 parasitic taxa observed. For caged fish, both diversity and equitability of parasite communities tended to be lower at the more eutrophic downstream sites; accordingly, parasite diversity and equitability were inversely correlated with nitrate concentrations. Ectoparasites were more prevalent in caged fish and endoparasites were more abundant in wild fish. An Ergasilus sp. copepod and a Posthodiplostomum sp. trematode dominated the ecto- and endoparasite faunas, respectively. This study suggests that assessment of watershed health can benefit from comparative cage studies of parasite community development involving sentinel fish species.

A preliminary survey of ectoparasites of small mammals in Kuala Selangor Nature Park

Trapping of small mammals was conducted at 5 study sites in Kuala Selangor Nature Park (KSNP) from 20-24 June 2005. A total of 11 animals comprising 2 species of rodents, Maxomys whiteheadi and Rattus exulans were caught from 3 sites, i.e from an area of mixed secondary forest and mangrove swamp; an area of mangrove swamp, and from an area of lalang fringing mangrove swamp. From these animals, the following 7 species of ectoparasites were found: Laelaps echidninus, Laelaps nuttalli, Ascoschoengastia indica, Leptotrombidium deliense, Hoplopleura pectinata, Hoplopleura pacifica and Polyplax spinulosa. One of the ectoparasites found, L. deliense is a known vector of scrub typhus and thus may pose potential health risks to visitors to KSNP.

Identifying risk factors for tungiasis and heavy infestation in a resource-poor community in northeast Brazil

Tungiasis is a neglected parasitic skin disease caused by penetration of female sand fleas into the epidermis. The ectoparasitosis is widespread in resource-poor communities in South America, the Caribbean and sub-Saharan Africa. To identify risk factors for the presence of sand fleas and severe infestation in an endemic community, we examined the entire population of a traditional fishing village for the presence of embedded sand fleas and determined the number and type of lesions. Demographic, behavioural and environmental characteristics of the population were assessed using a structured questionnaire. Multivariable analysis showed that both occurrence of tungiasis and heavy infestation were significantly related to poor housing conditions (odds ratio [OR]=4.7, 95% CI 1.4-15.8), lack of health education (OR=4.1, 95% CI 2.0-8.6) and presence of animals on the compound (OR=1.9, 95% CI 1.1-3.4). Contrary to common belief, a protective effect of frequent use of closed footwear could not be demonstrated. Based on the population attributable fractions calculated for the major risk factors identified, we conclude that several low-cost interventions would have a considerable impact on the occurrence of tungiasis and heavy infestation.

Ektoparasitosen

Hauterkrankungen stellen die dritthäufigste Gesundheitsstörung bei Tropenrückkehrern dar. Obwohl ektoparasitäre Affektionen nur einen Teil dieser Patienten betreffen, sind sie nicht selten Ursache für eine Konsultation beim Hausarzt nach der Reise. Die klinisch oft verkannte Krätze kann ebenso eine differentialdiagnostische Knacknuss sein wie Residuen von Arthropodenstichen. Hier können eine gezielte Anamnese und die sorgfältige klinische Untersuchung weiterhelfen. Allergische Reaktionen als Ausdruck einer individuellen Modulation immunologischer Prozesse werden bei vielen ektoparasitären Problemen beobachtet. Ferner sind spezifisch in den Tropen und Subtropen vorkommende Parasiten wie Sandflöhe und tropische Myiasen in die differentialdiagnostischen Überlegungen einzubeziehen. Mit geringem therapeutischem Aufwand kann eine bedeutende Linderung erheblicher subjektiver Beschwerden erreicht werden.

Field trial of the efficacy of a combination of imidacloprid and permethrin against Tunga penetrans (sand flea, jigger flea) in dogs in Brazil

In a field trial in Brazil 17 dogs penetrated by females of the jigger flea, Tunga penetrans, were topically treated with a combination of 10% imidacloprid and 50% permethrin (Advantix), while 17 dogs remained untreated. The follow-up controls on days 7, 14, 21 and 28 post-treatment clearly showed that, beginning from day 7, the flea load in treated dogs decreased, so that most of the dogs became free of tungiasis lesions, while in the untreated group the flea load remained high. Since the dogs distribute the flea eggs throughout the village, leading to a high incidence of tungiasis in humans, treatment of dogs probably also decreases the number of cases of tungiasis in the latter.

Size relationships between the parasitic copepod, Lernanthropus cynoscicola , and its fish host, Cynoscion guatucupa

The effects of the size of Cynoscion guatucupa on the size and demographic parameters of their parasitic copepod Lernanthropus cynoscicola were evaluated. Prevalence of copepods increased with host size up to fish of intermediate length, then it decreased, probably because changes in size of gill filaments affect their attachment capability, enhancing the possibility of being detached by respiratory currents. Body length of copepods was significantly correlated with host length, indicating that only parasites of an 'adequate' size can be securely attached to a fish of a given size. The absence of relationship between the coefficient of variability in copepod length and both host length and number of conspecifics, together with the host-size dependence of both male and juvenile female sizes, prevent to interpret this relationship as a phenomenon of developmental plasticity. Therefore, the observed peak of prevalence could reflect the distribution of size frequencies in the population of copepods, with more individuals near the average length. Concluding, the 'optimum' host size for L. cynoscicola could merely be the adequate size for most individuals in the population, depending, therefore, on a populational attribute of parasites. However, its location along the host size range could be determined by a balance between fecundity and number of available hosts, which increases and decreases, respectively, with both host and parasite size.

A survey of ectoparasites in Gunung Stong Forest Reserve, Kelantan, Malaysia

A survey of ticks and other ectoparasites was carried out during a national biodiversity scientific expedition at Gunung Stong Forest Reserve, Kelantan, Malaysia from 23-29 May 2003. A total of 272 animals comprised of 12 species of birds, 21 species of bats, 7 species of rodents and 2 species of insects were examined for ticks and other ectoparasites. From these animals, 5 species in 4 genera of ticks; 7 species in 2 families of Mesostigmatid mites and 5 species of chiggers were collected. Among the ectoparasites found were Ixodes granulatus and Leptotrombidium deliense, which are of known medical importance. A tick island consisting of 10 nymphal stages of Dermacentor spp was observed feeding on Rattus tiomanicus.

Cymothoa indica (Crustacea, Isopoda, Cymothoidae) parasitizes the cultured larvae of the Asian seabass Lates calcarifer under laboratory conditions

Parasitic disease in fishes is one of the most important factors limiting aquaculture production and its economic viability. Cymothoa indica, a cymothoid isopod, is reported here for the first time parasitizing cultured larvae of the Asian seabass Lates calcarifer in India. Fourteen-day-old L. calcarifer larvae of mean weight 8.73 +/- 0.03 mg were fed with wild zooplankton in the laboratory. On Day 14 of rearing, larvae were found parasitized by cymothoids. Infected larvae reached a mean (+/- SE) weight of 98.86 +/- 0.30 mg, while uninfected specimens weighed 117 +/- 0.43 mg at the end of the experiment (Day 21). C. indica occurred in the branchial and anterodorsal regions of infected fish, where resultant skin lesions were red, hemorrhagic, without scales and with abundant secreted mucus. The cumulative mortality over the 3 wk period was 16.54 %. These parasites are transferred to the host via the zooplankton used as food; this could easily be overcome, either by filtering wild zooplankton to remove the infectious swimming larvae of C. indica or by using cultured copepods.

Ectoparasites of road-killed vertebrates in northwestern South Carolina, USA

Road-killed animals are overlooked as the source of ectoparasites for monitoring vectors of zoonotic pathogens. We demonstrate that by exclusively sampling road-killed animals, a wide spectrum of vertebrate hosts and ectoparasites can be collected. Fifty-one species of ectoparasites were recovered from 35 species of road-killed vertebrates in northwestern South Carolina. Approximately, 11% of the total known terrestrial vertebrate species in the region were examined, which included more than 25% of the known mammal species. Our sampling techniques produced new state and regional records for chewing lice, ticks, and parasitic mites. Most ectoparasites were alive when they were collected, which would allow them to be screened for zoonotic pathogens.

What are the factors determining the probability of discovering a flea species (Siphonaptera)?

Our aim was to determine which of four variables (number of host species exploited by the parasite, taxonomic distinctness of these hosts, geographic range of the principal host, and year of description of this host) was the best predictor of description date of fleas. The study used previously published data on 297 flea species parasitic on 197 species of small mammals from 34 different regions of the Holarctic and one region from the Neotropics. We used both simple linear and multiple regressions to evaluate the relationships between the four predictor variables and the year of flea description, on species values as well as on phylogenetically independent contrasts. Whether or not the analyses controlled for flea phylogeny, all predictor variables correlated significantly with year of flea description when tested separately. In multiple regressions, however, the number of exploited host species was the best predictor of the date of flea description, with the geographic range of the principal host species as well as the date of its description having a lesser, though significant, influence. Overall, our results indicate that a flea species is more likely to be discovered and described early if its biological characteristics (exploitation of many host species) and those of its hosts (long-known to science, broad geographic distributions) increase its chances of being included in a collection. Because the variables we investigated only explained about 10-11% of the variation in year of description among flea species, other factors must be important, such as temporal variability in the activity of flea taxonomists.

Les puces (Insecta : Siphonaptera) parasites d’oiseaux : diversité taxonomique et dispersion biogéographique

If Mammals are the primary hosts of Siphonaptera, 6% of them have changed their trophic appetency for Birds. What are the reasons, what are the adaptations to be adopted by Fleas, what are the families or species groups of fleas concerned, and at last what are the host-families? As to this last question, it is clear that deviation was ecological but not phyletical.