Prevalence Of Tick Infestation Research Articles

Ectoparasites of goats in three agroecologies in central Oromia, Ethiopia

A cross-sectional study was conducted to determine the prevalence and risk factors for ectoparasites infestation in 979 goats in three agroecologies in central Oromia, Ethiopia from October 2009 through April 2010. The results of the study showed that of the total goats examined 487 (49.7 %) of them were infested with one or more ectoparasites. The ectoparasites identified were (16.5 %) Linognathus spp., 8.8 % Sarcoptes, 5 % Ctenocephalides spp. 11.8 % Amblyomma variegatum, 5.9 % Rhipicephalus evertsi evertsi, 4.3 % Rhipicephalus pravus, 1.6 % Boophilus decoloratus, 1.8 % Rhipicephalus sanguineus, 1.3 % Rhipicephalus praetextatus, and 0.4 % Hyalomma truncatum. Statistically significant (OR = 0.477, p = 0.000) difference was observed in prevalence of Linognathus stenopsis among highland, lowland and midland. Significantly higher prevalence of tick infestation in the lowland than both the midland and highland agroecology was recorded. The risk of tick infestations in lowland and midland was 2.841 and 5.635 times, respectively, higher than in highlands. Age-related variation was not observed in the prevalence of both Linognathus and tick infestations in examined goats. Significantly (OR = 7.864, p = 0.000) higher prevalence of sarcoptic mange in the lowland than the midland was observed. Goats in lowland were 7.864 times at higher risk for sarcoptic mange than those in the midlands. Sex-related variation in the prevalence of ectoparasites was never recorded in goats. Significantly higher prevalence of sarcoptic mange (OR = 0.266, p = 0.000) and Ctenocephalides spp. (OR = 2.430, p = 0.005) on young than adult goats was recorded. The logistic regression results showed statistically significant difference in prevalence of tick infestations (OR = 0.565, p = 0.000) and sarcoptic mange (OR = 0.582, p = 0.003) between goats with poor and good body condition. Further studies on role of ectoparasites in transmission of diseases to goats, comparative prevalence and load, and the importance of goats as alternative hosts in different agroecology and management systems in Ethiopia are recommended so as to design applicable control program in the country. Furthermore, the threat of ectoparasites on overall productivity of goats and the tanning industry warrants detail studies and urgent control intervention.

Ixodid ticks on ruminants, with on-host initiated moulting (apolysis) of Ixodes, Haemaphysalis and Dermacentor larvae

To screen the host-dependent abundance of hard tick (Acari: Ixodidae) developmental stages on ruminants in South Hungary, red and roe deer, as well as goats and sheep were examined in a season, when larvae and nymphs are active. Altogether 2271 ticks were collected. In the relevant period the prevalence of tick-infestation was significantly higher among goats, than among sheep kept in the very same area, most likely in association with the browsing habit of the former. Roe deer and goats were found to be important hosts for Ixodes ricinus and Haemaphysalis concinna larvae, in contrast to the view that this stage does not usually feed on medium-sized mammals. Interestingly, one third of I. ricinus larvae and one larva of H. concinna and of Dermacentor reticulatus collected from goats in the same herd in August have started the moulting process (showed apolysis) on their host, despite being three-host ticks. This is the first survey involving four species of domestic and wild ruminants in Europe to compare the host-preference of ixodid ticks in the same region.

Research Article: Parasitology Tsetse and Livestock Disease Situation in a Ranch and Surrounding Farms of Makueni District, Kenya

Surveys on vectors, livestock diseases and socio-economic issues were undertaken in June and August 2005 in Kiboko area, Makueni District of Kenya. It was deemed that the information generated would help to understand the farmersf awareness of the extent of tsetse and trypanosomosis and other diseases within and around Kiboko ranch. Over 500 head of cattle belonging to KARI and surrounding small scale farms were screened for parasites . tick-borne, trypanosomes, helminths and ticks. The farmers who presented their animals were interviewed to generate the socio-economic data. Biconical traps deployed were baited with acetone and 8.4.1.phenol sachets. A total of 21 tsetse flies (6 in June and 15 in August) were caught. Veterinary records from the area indicated the commonest diseases to be anaplasmosis, trypanosomosis and non-specific pneumonia in cattle. The overall trypanosome point prevalence in phase I and II were 3.9% and 0 respectively. On a four-point scale stratification the abundance of tick infestation in Kiboko was clean to low (Clean = 0; low . 20) with the overall tick infestation prevalence of 28.2%. Results on helminth-faecal egg count ranged from 0 . 4000 epgs with a mean 74.64. Skin diseases, trypanosomosis and tick-borne diseases (TBDs) were mentioned by the respondents as the most important livestock diseases in proportions of 61%, 50% and 36%, respectively. From this investigation, despite livestock playing a key role in the economy of farmers around Kiboko ranch, their knowledge of livestock diseases and their management was found to be low. In conclusion, trypanosomosis and TBDs as well as their vectors are still constraints to livestock production.

Prevalence and species composition of ixodid ticks infesting horses in three agroecologies in central Oromia, Ethiopia

A cross-sectional study was conducted to determine the species composition and prevalence of ixodid ticks infesting horses in three agroecological zones in central Ethiopia. For this purpose, a total of 1,168 horses were examined for tick infestation. An overall prevalence of 39.04% of tick infestation on horses was recorded. A total of 917 adult ticks were collected from infested horses. Amblyomma, Boophilus, Rhipicephalus, and Hyalomma genera with the respective prevalence of 3.2%, 1.8%, 29.2%, and 4.7% were identified. In the study, Rhipicephalus evertsi evertsi was encountered with the highest prevalence (15.8%) whereas Amblyomma gemma was with lowest prevalence (1.5%). From the highland, Hyalomma marginatum rufipes (3.1%), Hyalomma truncatum (1.0%), and Boophilus decoloratus (0.3%) were identified. From the midland, R. evertsi evertsi (27.5%), Rhipicephalus pulchellus (18%), Amblyomma variegatum (3.6%), B. decoloratus (2.8%), H. marginatum rufipes (2.6%), H. truncatum (1.8%), and A. gemma (1.5%) were identified. R. evertsi evertsi, 107 (27.5%), was with the highest prevalence in the midland. From the lowland, R. pulchellus (22.3%), R. evertsi evertsi (20%), H. truncatum (3.6%), A. gemma (3.1%), B. decoloratus (2.3%), H. marginatum rufipes (2.1%), and A. variegatum (1.5%) were identified. In the lowland, R. pulchellus, 87 (22.3%), was the most abundant tick species. The overall prevalence of tick infestation on horses was significantly (P<0.05) higher both in the midland, 225 (57.8%), and the lowland, 214 (54.87%), than the highland, 17 (4.4%). This suggests that horses in midland and lowland are at higher risk of tick infestation than those horses in the highland. Further studies on the role of ticks in transmission of diseases to equines and the importance of horses as alternative hosts in different parts of Ethiopia are needed.

Prevalence, distribution and risk associated with tick infestation of dogs in Great Britain

Current concerns over the potential impacts of climate change and the increased movement between countries of people and companion animals on the distribution of ectoparasites, highlight the need for accurate understanding of existing prevalence patterns. Without these future changes will not be detected. Here, the distribution and prevalence of tick infestations of domestic dogs in Great Britain were examined. A total of 173 veterinary practices were recruited to monitor tick attachment to dogs in their local areas between March and October 2009. Practices selected five dogs at random each week from those brought to the surgery and undertook a thorough, standardized examination for ticks. Each veterinary practice participated for 3 months before being replaced. Any ticks identified were collected and a sample sent to the investigators for identification, along with a clinical history of the dog. A total of 3534 dogs were examined; 810 dogs were found to be carrying at least one tick. Ixodes ricinus (Linnaeus) (Acari: Ixodidae) was identified in 72.1% of cases, Ixodes hexagonus Leach in 21.7% and Ixodes canisuga Johnston in 5.6% of cases. Five samples of Dermacentor reticulatus (Fabricius) (Acari: Ixodidae) were also found, adding to the growing evidence that an established population of D. reticulatus now exists in south-eastern England. Almost all the ticks found were adults. Overall, 19.2% of the veterinary practices reported no tick detections, 50% reported that ≥14.9% of the dogs seen were infested and 14.6% reported that >50% of the dogs inspected carried ticks. The estimated incidence of tick attachment was 0.013 per day in March (lowest) and 0.096 per day in June (highest). A number of risk factors affected the likelihood of tick attachment on dogs. Gundog, terrier and pastoral breed groups were more likely to carry ticks, as were non-neutered dogs. Dogs with shorter hair were less likely to have ticks, and dogs were most likely to carry a tick in June. This study is of value because, unusually, it presents the results of a randomized sample of dogs and gives a prevalence which is higher than those previously recorded in Great Britain.

Prevalence, associated determinants, and in vivo chemotherapeutic control of hard ticks (Acari: Ixodidae) infesting domestic goats (Capra hircus) of lower Punjab, Pakistan

A total of 800 goats of various breeds, age, and sex were randomly selected from Muzaffargarh (M. garh) and Layyah districts of lower Punjab, Pakistan. The selected goats were visited twice a month to collect information about determinants influencing goat tick infestation prevalence. For acaricidal efficacy, 360 tick-infested adult goats were subjected to an acaricidal treatment and post-treatment quantitative assessment of tick burden. Quantification of adult tick detachment 24 h post-treatment and the duration of treatment efficacy were calculated. Overall prevalence of goat tick infestation in both study districts was 60.1% (481/800). The prevalence was higher in district M. garh than in district Layyah. Tehsil-wise prevalence in district Layyah was highest in tehsil Layyah followed in order by Chaubara and Karor. In district M. garh, highest prevalence was found in tehsil M. garh followed by Kot Addu, Alipur, and Jatoi. Hyalomma a. anatolicum (75.9%; 365/481) and Rhipicephalus sanguineus (24.1%; 116/481) were the predominant species in both the districts. The highest month-wise prevalence was 56.9% and 62.7% in Layyah and M. garh districts, respectively, during July 2008, and the minimum (0%) prevalence was reported in November and December, respectively. Regarding host determinants, female goats were more heavily infested (72.8%) than males (47.5%), and younger animals were (63.5%) more burdened than older ones (56.7%). Teddy goats were the most susceptible breeds followed in order by Beetal, cross-bred, Nachi, and Dera Din Pannah. The preferred sites of attachment were inside and outside of the ear. Both the ivermectin (IVM)- and cypermethrin (CYM)-treated groups resulted in significantly lower (P < 0.05) tick counts relative to controls on all post-treatment counting days. The lowest tick burden in the IVM-treated group was significantly higher (P < 0.05) as compared to the CYM-treated group, the latter being close to zero. Hence, the in vivo efficacy trials of injectable IVM vs CYM pour-on revealed better results for the latter. These observations provided the first insights into what determinants impact goat tick infestation, and laid a foundation for planning of future control programs in the lower Punjab, Pakistan.

EPIZOOTIOLOGICAL STUDIES ON TICK INFESTATION AMONG DROMEDARY CAMELS IN UPPER EGYPT

The goal of the present work was to study tick infestation in camels in relation to different localities, age, sex and seasons. A total number of 1000 one humped camels were investigated, out of the investigated camels, three hundred and ninety were infested with ticks. The current work indicated that the prevalence of tick infestation of the examined camels located in Assiut, El-Minia and Sohag (River Nile Governorates) were 44.78%, 51.43% and 35.55% respectively. Meanwhile the prevalence rates of tick infestation of camels in the border governorates (El-Wady El-Gadid, Aswan and Shalatin) were 47.52%, 33.46% and 32.61% respectively. Statistical analysis revealed that there was no significant variation at P < 0.05 between prevalence rates of tick infestation in River Nile Governorates and Border Governorates. There was highly significant increase in prevalence of tick infestation in camels located in El-Wady El-Gadid governorate at P < 0.05. The prevalence of tick infestation of the examined camels was primarily increased by increasing the age of the animal and the infestation rate ranged from 8.7% to 44.78% (maximum) at 5.5 years. Thereafter, the prevalence of tick infestation was decreased by increasing in the age of infested camel and the percent of infection decreased from 44.78% till 7.41% at 15 years. The susceptibility rate of females (44.5%) to tick infestation was highly significant (p < 0.01) in contrast to males (37.20%). The percentage of infestation with ticks reached its peak (p < 0.01) at hot months of the year (44.3%). It could be concluded that prevalence of tick infestation in Upper Egypt reach its highest level in El-Wady El-Gadid governorate especially during the hot months of the year and camels 5.5 years of age is the most affected.

Tick prevalence and identification in calves in Al-Manathera city/Al-Najaf Al-Ashraf

A study was carried out in three months , to show the prevalence of tick infestation among feedlode calves in Al-Manathera region in Al-Najaf Al-Alashraf city . the infestation rate was 43.9 % (354 from 806 ) .Severity of infestation of calves were 23 % with 5-10 tick/animal which represent the highest rate , and 6 % with 21-25 tick/animal . which represent the lowest rate . The most infested area are perineum in a rate of 36.72 % ,while the less infested area are testis in a rate of 5.36 % . two genus were identified , which are Hyalomma spp. and Ixodes spp. In a rate of 43.7 % (146 tick from 404 ) and 56.2 % (258 tick from 404).

Transport of Ticks by Migratory Passerine Birds to Norway

Ticks can be transported over large distances and across geographical barriers by avian hosts. During the spring migrations of 2003 to 2005, 9,768 passerine birds from 4 bird observatories along the southern coastline of Norway were examined for ticks. Altogether, 713 birds carried a total of 517 larvae and 1,440 nymphs. The highest prevalence of tick infestation was observed in thrushes and dunnock (Prunella modularis). The degree of tick infestation varied during each season, between localities, and from year to year. Blackbirds (Turdus merula) caught in localities with many ticks had greater infestation than those from localities with few or no ticks, suggesting local tick recruitment. A similar study performed during 1965–1970 involving 2 of the bird observatories in the present study found ticks on 4.2% of birds, while we found infestation of 6.9% at the same localities (P < 0.001). With the exception of 10 nymphs and 1 larva, the predominant tick was Ixodes ricinus. Seven nymphs of Hyalomma rufipes and 1 larva of Dermacentor sp. were also found. No species of Dermacentor had previously been found in Norway.

Prevalence and associated risk factors for bovine tick infestation in two districts of lower Punjab, Pakistan

Bovine tick infestation is still a serious nuisance to livestock and the dairy industry of Pakistan. The current paper reports the prevalence and associated risk factors for bovine tick infestation in the districts Layyah and Muzaffargarh of lower Punjab, Pakistan. A questionnaire-based survey was conducted to identify and to quantify variation in the prevalence of bovine tick infestation with respect to host (age, species, sex, and breed) and environmental (geographical area and climate) determinants. Multiple stage cluster random sampling was used and 3500 cattle and buffaloes from the two districts were selected. Prevalence of bovine tick infestation was significantly higher (OR = 1.95; p < 0.05) in cattle (1076/1475; 72.9%) than in buffaloes (957/2025; 47.3%). Hyalomma anatolicum anatolicum was the major tick species (33.5%; 1173/3500), followed by Rhipicephalus sanguineus (13%; 456/3500). The highest monthly prevalence in both the districts was found in July. Ticks were not found in Layyah from November to March and in Muzaffargarh from December to March. The average number of ticks was proportional to the prevalence of infestation. Also, tick infestation in a 7 cm × 7 cm dewlap of the animal was proportional to that of the rest of body. Prevalence of tick infestation was associated ( p < 0.05) with district, host species and breed. In cattle, prevalence of tick infestation was associated ( p < 0.05) with age and sex of host. The results of this study provide better understanding of disease epidemiology in the study districts, which will help for planning of control strategies.

Detection ofBorrelia burgdorferisensu lato in Lizards and Their Ticks from Hungary

To investigate the involvement of lizard species in the natural cycle of Borrelia burgdorferi sensu lato (s.l.) in Hungary, a total of 186 reptiles belonging to three species--126 green lizards (Lacerta viridis), 40 Balkan wall lizards (Podarcis taurica), and 20 sand lizards (Lacerta agilis)--were captured in 2007 and 2008. All ticks removed from the lizards were Ixodes ricinus, either larvae (324/472; 68.6%) or nymphs (148/472; 31.4%). More than half (66/126; 52.4%) of L. viridis individuals were infested, and the prevalence of tick infestation on both the other two species was 35% each. All 472 I. ricinus ticks and tissue samples collected from 134 collar scales and 62 toe clips of lizards were further analyzed for the presence of B. burgdorferi s.l. with polymerase chain reaction. The amplification of B. burgdorferi s.l. DNA was successful in 8% (n = 92) of L. viridis, 9% (n = 32) of P. taurica, and 10% (n = 10) of L. agilis tissue samples. Restriction fragment length polymorphism genotyping identified the species Borrelia lusitaniae in all tested lizard samples. Prevalence of B. burgdorferi s.l. in ticks collected from L. viridis, P. taurica, and L. agilis was 8%, 2%, and 0%, respectively. Most of the infected ticks carried B. lusitaniae (74% of genotyped positives); however, Borrelia afzelii (5%) and B. burgdorferi sensu stricto (21%) were detected in ticks removed from green lizards and Balkan wall lizards, respectively. We conclude that lizards, particularly L. viridis, can be important hosts for I. ricinus larvae and nymphs; thus, they can be regarded as reservoirs of these important pathogen vectors. The role of green lizards has been confirmed, and the implication of Balkan wall lizards is suggested in the natural cycle of B. lusitaniae at our study site.

Survey of tick infestation in small ruminants of Miesso district, West Harergie, Oromia Region, Ethiopia

A survey was conducted to identify tick species and determine the prevalence of tick infestation in small ruminants of Miesso District, West Harergie Zone. Collection and identification of the ticks were undertaken from November 2007 to April 2008. All visible individual adult ticks were collected from the body of 328 goats and 40 sheep. The prevalence of tick infestation in goats and sheep was found to be 89.9% and 87.5%, respectively. In this study, ten species of ticks which grouped under four genera were identified. The most abundant species found in this study were Boophilus decoloratus (60%), Rhipicephalus pulchellus (25.1%), and Amblyomma gemma (11%). Hyalomma dromedarii was the minor species observed on goats. The difference in the prevalence of tick infestation between sheep and goats was not statistically significant (Chi( 2 ) = 0.22, p = 0.63) but found to be statistically significant between male and females (Chi( 2 ) = 9.8, p = 0.003). Attention should be given to the control and prevention of ticks, since they cause sever damage to the skins of small ruminants and thereby reduce the foreign exchange of the country; they also transmit some diseases which can cause sever loss to the productivity of these animals.

Trends in ixodid tick abundance and distribution in Great Britain

The popular, but rarely documented, view in Britain is that ticks have increased in distribution and abundance over recent years. To assess this, we gathered evidence for changes in tick distribution and abundance by distributing a survey questionnaire throughout Britain and by analysing trends in the prevalence of tick infestation on red grouse chicks Lagopus lagopus scoticus Latham (Galliformes: Tetranoidae), gathered over 19 years at three Scottish sites, and on deer (Cetartiodactyla: Cervidae) culled over 11 years on 26 Ministry of Defence (MoD) estates. Based on the survey, the current known distribution of Ixodes ricinus Linnaeus (Acari: Ixodidae) has expanded by 17% in comparison with the previously known distribution. The survey indicated that people perceive there to be more ticks today than in the past at 73% of locations throughout Britain. Reported increases in tick numbers coincided spatially with perceived increases in deer numbers. At locations where both tick and deer numbers were reported to have increased, these perceived changes occurred at similar times, raising the possibility of a causal link. At other locations, tick numbers were perceived to have increased despite reported declines in deer numbers. The perceptions revealed by the survey were corroborated by quantitative data from red grouse chicks and culled deer. Tick infestation prevalence increased over time on all grouse moors and 77% of MoD estates and decreased at six locations.

Some epidemiological aspects and vector role of tick infestation on layers in the Faisalabad district (Pakistan)

This study was carried out on some epidemiological aspects and vector role of ticks infesting layers in Faisalabad (Pakistan). The prevalence of tick infestation was found as 11% (88/800), 24% (192/800) and 12.7% (413/3250) on Indigenous, Babcock and White Leghorn varieties of layers, respectively. Two species of ticks namely Argas persicus (10%; 485/4,850) and Argas vespertilionis (3.5%; 170/4,850) were recorded. Tick infestation was found higher in summer months, in younger birds and in areas having densely located farms. The vector role of Argas persicus and Argas vespertilionis in the transmission of spirochaetosis in layer chicken was confirmed through isolation of Borrelia anserina from naturally infected ticks and their experimental transmission. Three species of bacteria namely Staphylococcus aureus, Salmonella pullorum and Escherichia coli were isolated from the triturated Argas persicus and Argas vespertilionis. Results of the present study were not different from those reported in literature, but for the first time in the study area. These results warrant for further research and also following effective tick control programs in order to save the farmers from economic losses.

A comparison of infestation patterns byIxodesticks in urban and rural populations of the Common BlackbirdTurdus merula

Although spatial variation in the patterns of parasite infestations among host populations may have important ecological and epidemiological consequences, the causes underlying such variation are poorly known. In the context of a long‐term study on the population biology of Common BlackbirdsTurdus merula, we examined the prevalence and intensity of infestation byIxodesticks between birds living in rural vs. urban habitats. The overall prevalence of tick infestations was significantly higher in the rural habitat where 74% of individuals (n = 130) were infested. This result contrasted markedly with the situation in the urban habitat where less than 2% of individuals (n = 360) carried ticks. There was no significant effect of the sex of the host on the intensity or prevalence of tick infestations. There was a significant effect of the age of the host on tick infestations essentially due to the absence of ticks on nestlings. Possible mechanisms responsible for the differences between habitats could include differences in tick survival and/or host resistance towards ticks. Previous studies have shown higher population densities and suggested longer survival for Blackbirds in urban than in rural habitats. Given that ixodid ticks are known to transmit pathogens likeBorreliaspp. to wild birds, and that Blackbirds can act as reservoirs for these pathogens, the infection patterns observed in our study area provide a suitable situation to study the interrelations between ticks, Blackbirds and pathogens.

Birds and their ticks in northwestern California: minimal contribution to Borrelia burgdorferi enzootiology.

Birds and their attendant ticks were surveyed for infection with the Lyme disease spirochete Borrelia burgdorferi, in chaparral and woodland-grass habitats in northwestern California from March to July, 1998 to 1999. In total, 234 birds were captured and recaptured (15%); nearly 2.5 times more birds were captured in chaparral than in woodland-grass. Overall, 34 species representing 15 families were collected during this study; of these, 24 species were caught in chaparral, 19 in woodland-grass, and 9 in both vegetational types. The most frequently captured birds were sage sparrows (Amphispiza belli) in chaparral, and American robins (Turdus migratorius) and oak titmice (Baelophus inornatus) in woodland-grass. Birds hosted 35 Ixodes pacificus (15 larvae, 20 nymphs) and 9 Haemaphysalis leporispalustris (3 larvae, 5 nymphs, 1 adult) ticks, of which 32 were removed from chaparral birds and 12 from woodland birds. The prevalence of tick infestation was 13% (21/167) in chaparral and 5% (3/67) in woodland-grass, but the relative and mean tick intensities of 0.19 and 1.5 for chaparral birds, and 0.18 and 4.0 for woodland birds, respectively, did not differ significantly by habitat. Spirochetes were not detected in either bird-blood or tick-tissue samples when tested by culture, immunofluorescence, or Giemsa-staining. In contrast, over 90% (86/94) of western fence lizards (Sceloporus occidentalis) collected in June or July were infested with an average of 6.9 and 8.9 immature I. pacificus in chaparral and woodland-grass, respectively. We conclude that birds contribute little to the enzootiology of B. burgdorferi in chaparral and woodland-grass habitats in northwestern California because of their limited parasitism by tick vectors and lack of detectable spirochetemias.

Human otoacariasis

Accidental entry of insects and other arthropods is a common aetiology of aural foreign bodies (FB) presenting to accident and emergency departments. A retrospective study revealed that the FB in almost half (148) of 348 cases of aural FB investigated at the Universiti Sains Malaysia Hospital was an arthropod. The most common arthropod encountered was the cockroach, followed by a cattle tick. The high prevalence of tick infestation of the human ear canal (i.e. human otoacariasis) currently appears to be unique to the Malaysian state of Kelantan. The presentation of patients with intra-aural ticks, the methods used to remove the ticks, the complications encountered, and recommendations for an appropriate course of action in such cases are discussed.

Seasonal distribution of Rhipicephalus sanguineus ticks (Acari: Ixodidae) on dogs in an urban area of Morelos, Mexico.

Between 1993 and 1995, we examined 1742 dogs at two veterinary clinics in Cuernavaca City in Mexico for the presence of Rhipicephalus sanguineus ticks. The overall tick infestation prevalence was 20% and there were no significant differences (p > 0.05) between different years. The prevalence was somewhat higher in spring, summer and autumn (20% or more) than in winter (13.7%). A positive correlation (p < 0.01) was found between prevalence of ticks and rainfall in spring, summer and autumn, whereas in winter there was only a correlation with temperature. Different stages of the tick were found and it was calculated that 2.5 generations could be completed each year. It is concluded that the environmental conditions of Cuernavaca City favour development and maintenance of R. sanguineus ticks throughout the year and that its role as a vector of diseases poses a threat to dogs and may have potential zoonotic risks.

Abundance of ticks (Acari: Ixodidae) infesting the western fence lizard, Sceloporus occidentalis, in relation to environmental factors.

We examined the impact of environmental characteristics, such as habitat type, topographic exposure and presence of leaf litter, on the abundance of Ixodes pacificus ticks infesting the western fence lizard (Sceloporus occidentalis) at the University of California Hopland Research and Extension Center (HREC), Mendocino County, California. A total of 383 adult lizards were slip-noosed and examined for tick infestation in April and May 1998. At least 94% of the lizards were infested by ticks and at least 20% of the females and 33% of the males carried > 15 ticks. This intensive utilization of western fence lizards (which do not serve as natural reservoirs for Lyme disease spirochetes) by subadult ticks, is probably the primary reason for the low prevalence of infection with Borrelia burgdorferi in I. pacificus nymphs and adults previously recorded at the HREC. Tick loads were higher on male than female lizards. Also, male lizards were generally more heavily infested in late April than in late May. The prevalence of tick infestation exceeded 88% in all habitat types but males collected in woodland and grass/woodland edges had higher tick loads than those collected in open grassland. Male lizards captured in open, exposed grassland tended to carry heavier tick loads in northern/eastern, as compared to southern/western, exposures, and when leaf litter was present.

Studies on Some Ecological Aspects of Tick West Azarbidjan, Iran

Abstract Rahbari, S. 1995. Studies on some ecological aspects of tick fauna of west Azarbidjan, Iran. J. Appl. Anim. Res., 7: 189–194. The study on tick population of sheep, goat and cattle was conducted in six villages of northwest of Iran. Out of the nine species of ixodid ticks recorded, Ornithodorua lohorxmsis was the only argasid tick, which infested sheep, goat and cattle. The prevalence of tick infestation on sampled animals was 55%, 57% and 62% in sheep, goat and cattle respectively. The comparative tick yield obtained from different species of animals in each of the six villages showed no significant difference within mean tick number, however, the predilection site of ticks per animal showed the largest number on head, axilla and groin. The seasonal distribution of tick indicated that hard ticks were apparently found throughout the year, but were more abundant in spring and least in autumn. Whereas, soft ticks were observed only during autumn up to late winter. The maximum tick count per animal was 21–50 when microhabitat determined at 10–20C and 50–70% relative humidity.