Acaricide resistance status of livestock ticks from East and West Africa and in vivo efficacy of acaricides to control them

Through a collaborative effort across six Sub-Saharan African countries, using recognized international assessment techniques, 23 stocks of three tick species (Rhipicephalus microplus, Rhipicephalus appendiculatus and Amblyomma variegatum) of economic importance for rural small holder farming communities from East and West Africa were collected from cattle, and evaluated in in vitro larval packet tests (LPT). The results demonstrated medium to high resistance to chlorfenvinphos and amitraz across species. Rhipicephalus microplus demonstrated high level alpha-cypermethrin and cypermethrin resistance. Stocks of A. variegatum (West Africa) and R. appendiculatus (Uganda) demonstrated medium level ivermectin resistance. The four least susceptible stocks (East and West African R. microplus, A. variegatum and R. appendiculatus) were taken into in vivo controlled cattle studies where fipronil was found effective against West and East African R. microplus isolates although persistent efficacy failed to reach 90%. Cymiazole and cypermethrin, and ivermectin based acaricides were partially effective against R. microplus without persistent efficacy. Flumethrin spray-on killed A. variegatum within 72 h for up to 10 days posttreatment, however product application was directly to tick attachment sites, which may be impractical under field conditions. A flumethrin pour-on formulation on goats provided persistent efficacy against A. variegatum for up to one-month. Therapeutic control was achieved against R. appendiculatus through weekly spraying cattle with flumethrin, amitraz or combined cymiazole and cypermethrin. A fipronil pour-on product offered four-week residual control against R. appendiculatus (with slow onset of action). Few studies have assessed and directly compared acaricidal activity in vitro and in vivo. There was some discordance between efficacy indicated by LPT and in vivo results. This observation calls for more research into accurate and affordable assessment methods for acaricide resistance. No single active or product was effective against all three tick species, emphasising the need for the development of alternative integrated tick management solutions.

Survey of ectoparasites affecting dog and cat populations living in sympatry in Gamo Zone, Southern Ethiopia

BACKGROUND

Ectoparasites of dogs and cats are implicated to be responsible for life-threatening anaemia, allergic dermatitis and pruritic and non-pruritic skin disorders. In Ethiopia, few studies have been conducted on the arthropods of dogs and cats.

OBJECTIVES

In order to shed light on some of these aspects, a survey was conducted to investigate the presence of ectoparasites in dogs and cats living in sympatry in the urban and rural areas of Gamo Zone, Ethiopia.

METHODS

A total of 297 dogs and 110 cats were examined for ectoparasites, and questionnaires were employed to obtain information concerning owner's knowledge about arthropods and vector-borne diseases (VBDs).

RESULTS

The overall prevalence of ticks, fleas and lice in dogs was 36.7%, 69.7% and 4.7%, respectively. Similarly, on cats, an overall prevalence of 2.7% ticks and 21.8% fleas was recorded. On dogs, fleas (Ctenocephalides felis 69.4%, Echidnophaga gallinacea 1.3%, Ctenocephalides canis 1.0% and Pulex irritans 0.3%), ticks (Amblyomma variegatum 22.9%, Rhipicephalus sanguineus 14.1%, Haemaphysalis leachi 8.8%, Rhipicephalus praetextatus 4.0% and Rhipicephalus pulchellus 3.4%) and lice (Heterodoxus spiniger 4.0% and Trichodectes canis 0.7%) were identified. Likewise, on cats, fleas (C. felis [15.5%] and E. gallinacea [7.3%]) and ticks (H. leachi [2.7%]) were identified. The abundance of C. felis was significantly higher (p < 0.001) on dogs, whereas in cats, the abundance of E. gallinacea was significantly higher (p = 0.002) than the other ectoparasites. On dogs, a significantly higher prevalence of Rh. sanguineus was recorded in urban areas (<0.001) and on dogs which live in indoor environments (p = 0.003) than on dogs which live in other environments. On the other hand, the prevalence of A. variegatum in rural areas and midland agroecology was significantly higher (p < 0.001). The prevalence of H. leachi was significantly higher in midland (p < 0.001) and on adult dogs (p = 0.001). Overall, fleas were more prevalent in rural (p = 0.029) than in urban areas, and female dogs were with higher infestation than the male (p = 0.047) dogs; C. felis was prevalent in female (p = 0.038) dogs than males. Overall, 88.3% owners in the study area had no knowledge about ectoparasites and VBDs of dogs and cats. Majority of the owners (64.8%) attest that they had never visited veterinary clinics.

CONCLUSIONS

In conclusion, the data presented in the present study provide additional knowledge on the importance of ectoparasites of dogs and cats and are believed to contribute in awareness creation and strengthening of veterinary services of dogs and cats of the study area.

Data release: targeted systematic literature search for tick and tick-borne pathogen distributions in six countries in sub-Saharan Africa from 1901 to 2020

BACKGROUND

Surveillance data documenting tick and tick-borne disease (TBD) prevalence is needed to develop risk assessments and implement control strategies. Despite extensive research in Africa, there is no standardized, comprehensive review.

METHODS

Here we tackle this knowledge gap, by producing a comprehensive review of research articles on ticks and TBD between 1901 and 2020 in Chad, Djibouti, Ethiopia, Kenya, Tanzania, and Uganda. Over 8356 English language articles were recovered. Our search strategy included 19 related MeSH terms. Articles were reviewed, and 331 met inclusion criteria. Articles containing mappable data were compiled into a standardized data schema, georeferenced, and uploaded to VectorMap.

RESULTS

Tick and pathogen matrixes were created, providing information on vector distributions and tick-pathogen associations within the six selected African countries.

CONCLUSIONS

These results provide a digital, mappable database of current and historical tick and TBD distributions across six countries in Africa, which can inform specific risk modeling, determine surveillance gaps, and guide future surveillance priorities.

Biting Flies and Associated Pathogens in Camels in Amibara District of Afar Region, Ethiopia

Biting flies and associated pathogens are the major health constraints on camel production and productivity and are implicated in causing significant economic losses in the pastoralist community in Ethiopia. A cross-sectional study was conducted to estimate the prevalence of biting flies and their associated pathogens in relation to different risk factors in camels in the Amibara district, from October 2019 to April 2020. A total of 480 camels were examined for biting flies and associated pathogens. The study revealed that overall, 87% (418/480) and 18% (87/480) of camels were infested by one or more biting flies and infected with Trypanosoma evansi during the study period, respectively. The collected biting flies were identified into a total of 3 genera: Hippobosca, Stomoxys, and Tabanus under the stereomicroscope. In the present study, Hippobosca (40.4%) was the most prevalent biting fly, followed by Stomoxys (31%) and Tabanus (28.6%), which affected camels in the study area. Among camels infected with Trypanosoma evansi, 7.3% and 16% were positive for parasitological and serological tests, respectively. Age, body condition score, and season appeared to have a significant effect (p ≤ 0.005) on the prevalence of biting flies and T. evansi on dromedaries. According to the findings of this study, biting flies and Trypanosoma evansi were the most common limitations on camel health, production, and productivity in the study area. As a result of the possible threat of biting flies' infestation and Trypanosoma evansi on camels, all-around attention is required in terms of strategic acaricide application, proper antiprotozoal drug use, and raising knowledge about acaricide use to prevent and control biting flies' infestation.

Tick communities of cattle in smallholder rural livestock production systems in sub-Saharan Africa

BACKGROUND

The majority of the African population lives in rural areas and depends on agriculture for their livelihoods. To increase the productivity and sustainability of their farms, they need access to affordable yield-enhancing inputs of which parasite control is of paramount importance. We therefore determined the status of current tick species with the highest economic impact on cattle by sampling representative numbers of animals in each of seven sub-Saharan countries.

METHODS

Data included tick species' half-body counts from approximately 120 cattle at each of two districts per country, collected four times in approximately 1 year (to include seasonality). Study sites were chosen in each country to include high cattle density and tick burden.

RESULTS

East Africa (Ethiopia, Uganda and Tanzania) showed overall a higher diversity and prevalence in tick infestations compared to West African countries (Benin, Burkina Faso, Ghana and Nigeria). In East Africa, Amblyomma variegatum (vector of Ehrlichia ruminantium), Rhipicephalus microplus (Babesia bovis, B. bigemina, Anaplasma marginale), R. evertsi evertsi (A. marginale) and R. appendiculatus (Theileria parva) were the most prevalent tick species of economic importance. While the latter species was absent in West Africa, here both A. variegatum and R. microplus occurred in high numbers. Rhipicephalus microplus had spread to Uganda, infesting half of the cattle sampled. Rhipicephalus appendiculatus is known for its invasive behaviour and displacement of other blue tick species, as observed in other East and West African countries. Individual cattle with higher body weights, as well as males, were more likely to be infested. For six tick species, we found reduced infestation levels when hosts were treated with anti-parasiticides.

CONCLUSIONS

These baseline data allow the determination of possible changes in presence and prevalence of ticks in each of the countries targeted, which is of importance in the light of human-caused climate and habitat alterations or anthropogenic activities. As many of the ticks in this study are vectors of important pathogens, but also, as cattle may act as end hosts for ticks of importance to human health, our study will help a wide range of stakeholders to provide recommendations for tick infestation surveillance and prevention.

Tick-borne pathogens and body condition of cattle in smallholder rural livestock production systems in East and West Africa

BACKGROUND

The majority of the African population lives in rural areas where they heavily depend on crop and livestock production for their livelihoods. Given their socio-economic importance, we initiated a standardized multi-country (Benin, Burkina Faso, Ghana, Nigeria, Ethiopia Tanzania and Uganda) surveillance study to assess the current status of important tick-borne haemoparasites (TBHPs) of cattle.

METHODS

We assessed pathogen prevalences (Anaplasma marginale, Anaplasma centrale, Babesia bigemina, Babesia bovis, Ehrlichia ruminantium, and Theileria parva) in the blood of 6447 animals spread over fourteen districts (two districts per country). In addition, we screened for intrinsic (sex, weight, body condition) and extrinsic (husbandry, tick exposure) risk factors as predictors of infections with TBHPs.

RESULTS

There was a large macro-geographic variation observed in A. marginale, B. bigemina, B. bovis and E. ruminantium prevalences. Most correlated with the co-occurrence of their specific sets of vector-competent ticks. Highest numbers of infected cattle were found in Ghana and Benin, and lowest in Burkina Faso. While T. parva was seldomly found (Uganda only: 3.0%), A. marginale was found in each country with a prevalence of at least 40%. Babesia bovis infected individuals had lower body condition scores. Age (as estimated via body weight) was higher in A. marginale infected cattle, but was negatively correlated with B. bigemina and E. ruminantium prevalences. Ehrlichia ruminantium infection was more often found in males, and A. marginale more often in transhumance farming. High levels of co-infection, especially the combination A. marginale × B. bigemina, were observed in all countries, except for Uganda and Burkina Faso. Babesia bigemina was more or less often observed than expected by chance, when cattle were also co-infected with E. ruminantium or A. marginale, respectively.

CONCLUSIONS

Tick-borne pathogens of cattle are ubiquitous in African's smallholder cattle production systems. Our standardized study will help a wide range of stakeholders to provide recommendations for TBHP surveillance and prevention in cattle, especially for B. bovis which heavily impacts production and continues its spread over the African continent via the invasive Rhipicephalus microplus tick.

Dry Season Eimeria Infection in Dairy Cattle and Sheep in and Around Adama and Bishoftu Towns, Oromia, Ethiopia

Introduction

Eimeria infection is one of the protozoal diseases of animals caused by various species of Eimeria (intracellular parasite) and causes reduced productivity and mortality in ruminants, especially in young ones. Despite the fact that the disease is one of the leading causes of economic losses, there is little information in Ethiopia on the occurrence of the infection in cattle and sheep.

Methods

A cross-sectional study was conducted from December 2021 to April 2022 in and around Adama and Bishoftu towns with the objectives to estimate the prevalence of Eimeria infection; identify circulating Eimeria oocysts, the intensity/burden of infection and associated risk factors of Eimeria infection in cattle and sheep. A total of 384 randomly selected (265 cattle and 119 sheep) fecal samples were collected from the rectum and examined by flotation technique using sheather’s sugar solution to detect the oocysts of Eimeria. A 2.5% potassium dichromate solution was added to the positive fecal samples for sporulation of the oocysts.

Results and discussion

The overall prevalence of 48.95% Eimeria infection was recorded during the study. 45.0% and 58% prevalence of the infection was registered in cattle and sheep, respectively. There was a statistically significant difference (P ˂ 0.05) in Eimeria infection between the study animal species, age of the animals, breed, farm hygiene and management system. However, there was no significant difference in Eimeria infection (P > 0.05) in sex, body condition of the animals and fecal consistency. The maximum oocysts per gram of feces was found to be 10,000. Eimeria infection is of great importance to livestock producers and requires serious control and prevention initiatives.

Multi-country investigation of the diversity and associated microorganisms isolated from tick species from domestic animals, wildlife and vegetation in selected african countries

In many areas of Africa, recent studies highlighted the great impact of ticks on animal and human health throughout the continent. On the other hand, very limited information on the bacterial endosymbionts of the African ticks and their pattern of co-infections with other bacteria are found in literature, notwithstanding their pivotal role in tick survival and vector efficiency. Thus, we investigated the distribution of selected pathogenic and symbiotic bacteria in hard ticks collected from wild, domestic animals and from vegetation in various ecological zones in Africa and their co-occurrence in the same tick host. Overall, 339 hard ticks were morphologically identified as belonging to the genera Amblyomma, Dermacentor, Hyalomma, Haemaphysalis, Ixodes and Rhipicephalus. Molecular screening provided information on pathogens circulation in Africa, detecting spotted fever group rickettsiae, Anaplasma spp., Ehrlichia ruminantium, Borrelia garinii, Babesia spp., Theileria spp. and Coxiella burnetii. Furthermore, our work provides insights on the African scenario of tick-symbiont associations, revealing the presence of Coxiella, Francisella and Midichloria across multiple tick populations. Coxiella endosymbionts were the most prevalent microorganisms, and that with the broadest spectrum of hosts, being detected in 16 tick species. Francisella was highly prevalent among the Hyalomma species tested and correlated negatively with the presence of Coxiella, showing a potential competitive interaction. Interestingly, we detected a positive association of Francisella with Rickettsia in specimens of Hy. rufipes, suggesting a synergistic interaction between them. Finally, Midichloria was the most prevalent symbiont in Rhipicephalus sanguineus sensu lato from Egypt.

Out-of-Africa, human-mediated dispersal of the common cat flea, Ctenocephalides felis: The hitchhiker's guide to world domination

The cat flea (Ctenocephalides felis) is the most common parasite of domestic cats and dogs worldwide. Due to the morphological ambiguity of C. felis and a lack of - particularly largescale - phylogenetic data, we do not know whether global C. felis populations are morphologically and genetically conserved, or whether human-mediated migration of domestic cats and dogs has resulted in homogenous global populations. To determine the ancestral origin of the species and to understand the level of global pervasion of the cat flea and related taxa, our study aimed to document the distribution and phylogenetic relationships of Ctenocephalides fleas found on cats and dogs worldwide. We investigated the potential drivers behind the establishment of regional cat flea populations using a global collection of fleas from cats and dogs across six continents. We morphologically and molecularly evaluated six out of the 14 known taxa comprising genus Ctenocephalides, including the four original C. felis subspecies (Ctenocephalides felis felis, Ctenocephalides felis strongylus, Ctenocephalides felis orientis and Ctenocephalides felis damarensis), the cosmopolitan species Ctenocephalides canis and the African species Ctenocephalides connatus. We confirm the ubiquity of the cat flea, representing 85% of all fleas collected (4357/5123). Using a multigene approach combining two mitochondrial (cox1 and cox2) and two nuclear (Histone H3 and EF-1α) gene markers, as well as a cox1 survey of 516 fleas across 56 countries, we demonstrate out-of-Africa origins for the genus Ctenocephalides and high levels of genetic diversity within C. felis. We define four bioclimatically limited C. felis clusters (Temperate, Tropical I, Tropical II and African) using maximum entropy modelling. This study defines the global distribution, African origin and phylogenetic relationships of global Ctenocephalides fleas, whilst resolving the taxonomy of the C. felis subspecies and related taxa. We show that humans have inadvertently precipitated the expansion of C. felis throughout the world, promoting diverse population structure and bioclimatic plasticity. By demonstrating the link between the global cat flea communities and their affinity for specific bioclimatic niches, we reveal the drivers behind the establishment and success of the cat flea as a global parasite.

Cystic echinococcosis in slaughtered cattle at Addis Ababa Abattoir enterprise, Ethiopia

Cystic echinococcosis, caused by larval stages of the tapeworm Echinococcus granulosus, is responsible for hydatid cysts in the lungs, liver and other organs of intermediate hosts. A cross-sectional Abattoir study was conducted from October 2015 to May 2016 at Addis Ababa Abattoir enterprise, Ethiopia. For this purpose a total of 1209 cattle were examined using the classical meat inspection procedure for the presence of hydatid cysts. An overall prevalence of 21% (254/1209) of hydatid cyst was recorded in cattle slaughtered at Addis Ababa Abattoir enterprise. The prevalence of hydatid cyst was statistically significantly higher (P<0.05) in cattle with the age group of >6 years than those cattle with all other age categories. The study showed that lungs and livers were the most affected organs of cattle. Significantly (P < 0.05) higher overall number of hydatid cysts were observed in the lungs (63.9%; 1324/2071) than in the livers (35.4%; 734/2071). The study revealed the presence of an overall of 84.1% (333/396) sterile, 12.2% (48/396) calcified and 4.3% (17/396) fertile cysts. Of the total of 17 fertile hydatid cysts tested for viability, 17.6% (3/17) viable and 82.3% (14/17) nonviable cysts were observed. Overall, findings of the present study showed the widespread occurrence of hydatid cysts in internal organs of cattle that possibly incur significant economic losses through condemnation of edible organs rendering unfit for human consumption. Molecular studies on the role of intermediate host species, genotypes of E. granulosus, zoonotic impact and economic significance of echinococcosis are needed in different parts of Ethiopia.

Ectoparasites infesting dogs and cats in Bishoftu, central Oromia, Ethiopia

A total of 200 dogs and 137 cats were examined for the presence of fleas, ticks and lice in Bishoftu, central Oromia, Ethiopia from September 2009 through April 2010. At least one ectoparasite species was found on 97% (194/200) of the dogs and 90.5% (124/137) of the cats. On dogs, fleas (Ctenocephalides felis (95%), Pulex irritans (20.5%), Echidnophaga gallinacea (9%) and Xenopsylla cheopis (0.5%)), ticks (Haemaphysalis leachi (17.5%), Amblyomma variegatum (8.5%), Rhipicephalus sanguineus (8%), Rhipicephalus pulchellus (5.5%) and Rhipicephalus (Boophilus) decoloratus (2.5%)) and lice (Heterodoxus spiniger (5%), Linognathus setosus (1.5%) and Trichodectes canis (0.5%)) were identified. On cats, fleas (C. felis (61.7%), E. gallinacea (24.1%), P. irritans (1.5%) and X. cheopis (0.7%)) and ticks (Ha. leachi (10.9%), Am. variegatum (1.5%) and Rh. sanguineus (0.7%)) were identified. C. felis was identified as the predominant ectoparasite on both dogs and cats. The overall frequency and count of ectoparasites was higher on dogs than on cats. Significantly higher overall frequency of fleas on young versus adult cats (p = .01) was recorded. However, ticks were significantly higher on adult cats than on young cats (p = .01). In conclusion, this study demonstrated great species diversity and high frequency of ectoparasites on dogs and cats in the study area. Further studies are required to investigate the role of these ectoparasites in transmission of zoonotic pathogens to humans and animals in Ethiopia.

First record of the nematode Libyostrongylus dentatus Hoberg, Lloyd & Omar, 1995 (Trichostrongylidae) in ostriches (Struthio camelus Linnaeus, 1758) (Struthionidae) outside the Americas

Background

Libyostrongylus douglassii, Libyostrongylus dentatus and Libyostrongylus magnus are nematodes that infect ostriches. The first species has been identified in ostriches from Africa, Europe, Americas and Oceania. Although the natural range of ostriches is Africa, L. dentatus was first described in birds from the USA and later identified in Brazil, where co-infections with L. douglassii have been commonly reported. Libyostrongylus magnus is known from the original description only. There are a few reports on infections with L. douglassii in ostriches from Africa and all farmed birds examined are from the southern region of the continent. The aim of this report was to verify Libyostrongylus spp. infections in wild ostriches from Ethiopia. Fecal samples from ostriches, Struthio molybdophanes, were collected and submitted to coproculture. Infective larvae were identified to the species level based on general morphology and morphometry. In addition, phylogenetic analysis of the first and second internal transcribed spacer (ITS1 and ITS2) of the nuclear ribosomal DNA was performed.

Results

Infective larvae from Ethiopian ostriches had the morphological characteristics of L. dentatus. Confidence interval estimate for sheath tail length from Ethiopian Libyostrongylus sp. isolates overlapped one for Brazilian L. dentatus. Neighbor-joining and Maximum Likelihood phylogenetic trees based on sequences of the ITS1 and ITS2 regions revealed that the Ethiopian samples belong to the L. dentatus species clade. Monospecific infections with L. dentatus were confirmed in Ethiopian wild ostriches, opposed to the co-infections typically found in the Americas.

Conclusions

To our knowledge, this is the first record of L. dentatus from African ostriches, the region from which this parasite originated.

Anaplasma, Ehrlichia and rickettsial pathogens in ixodid ticks infesting cattle and sheep in western Oromia, Ethiopia

Although ticks are widely distributed in all agro-ecological zones of Ethiopia, information on tick-borne pathogens is scarce. This study was conducted to determine the presence of Anaplasma spp., Ehrlichia spp., and Rickettsia spp. in Rhipicephalus evertsi and Rhipicephalus (Boophilus) decoloratus collected from cattle and sheep at Bako, western Oromia, Ethiopia, using polymerase chain reaction and sequencing. Anaplasma ovis and Anaplasma spp., Ehrlichia ruminantium and Ehrlichia spp. were detected in Rh. decoloratus, whereas only A. ovis was detected in Rh. evertsi. Both tick species were found to harbor DNA belonging to Rickettsia spp., and Rickettsia africae. Our findings highlight the risk of infection of animals and humans with these zoonotic tick-borne bacteria in Ethiopia.

Morphological, molecular and MALDI-TOF mass spectrometry identification of ixodid tick species collected in Oromia, Ethiopia

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) technology has recently been reported as a promising method for arthropods identification. More recently, our laboratory reported the correct identification of tick species via the MALDI-TOF MS protein spectra profiling of legs from fresh specimens. The aim of the present study was to assess the use of MALDI-TOF MS for correct identification of ixodid tick species preserved in 70 % ethanol during field collection in Ethiopia. Following morphological identification of 12 tick species, the legs from 85 tick specimens were subjected to MALDI-TOF MS. Spectral analysis revealed an intra-species reproducibility and inter-species specificity that were consistent with the morphological classification. To support the results of the MALDI-TOF MS tick species identification, 41 tick specimens comprising 3 to 5 specimens per tick species were used to create a reference spectra database, which was evaluated using the spectra of the 44 remaining tick specimens. The blind tests revealed that 100 % of the tick specimens studied by MALDI-TOF MS were correctly identified. A relevant Log score value (LSV) of >1.8 was recorded for all of the tick species studied by MALDI-TOF MS, except for Rhipicephalus praetextatus. The morphological and MALDI-TOF MS identifications were confirmed by sequencing the 12S ribosomal RNA (rRNA) gene of 40 tick specimens belonging to 11 ixodid species. Taken together, the results of the present study indicate that MALDI-TOF MS is a reliable tool for tick species identification, even after preservation in ethanol, provided that a reference spectra database is built from specimens that represent the respective species stored under the same conditions.

Occurrence and Genotyping of Coxiella burnetii in Ixodid Ticks in Oromia, Ethiopia

This study was conducted from September 2011 to March 2014 to address the occurrence and genotypes of Coxiella burnetii using molecular methods in ticks collected from domestic animals in Ethiopia. Ticks were tested for C. burnetii by quantitative real-time polymerase chain reaction (qPCR) targeting two different genes followed by multispacer sequence typing (MST). An overall prevalence of 6.4% (54/842) of C. burnetii was recorded. C. burnetii was detected in 28.6% (14/49) of Amblyomma gemma, 25% (31/124) of Rhipicephalus pulchellus, 7.1% (1/14) of Hyalomma marginatum rufipes, 3.2% (2/62) of Am. variegatum, 3.1% (4/128) of Am. cohaerens, 1.6% (1/63) of Rh. praetextatus, and 0.6% (1/153) of Rhipicephalus (Boophilus) decoloratus. Significantly higher overall frequencies of C. burnetii DNA were observed in Am. gemma and Rh. pulchellus than in other tick species (Mantel-Haenszel [MH], P < 0.0001). The overall frequency of C. burnetii was significantly higher (MH, P < 0.0001) in ticks from southeastern districts (Arero, Moyale, and Yabelo) than that from other districts. This study demonstrated the presence of C. burnetii genotype MST 18 in ticks in southeastern districts and genotype MST 20 in ticks in central districts. This study highlights the importance of ticks in the epidemiology of C. burnetii in Ethiopia.

Mites of sheep and goats in Oromia Zone of Amhara Region, North Eastern Ethiopia: species, prevalence and farmers awareness

Background

Mites are one of the most common and widely distributed ectoparasites of small ruminants in Ethiopia, contributing to major hindrances in livestock productivity in the country. Despite of this fact, specific study was not conducted on mites of small ruminants in Ethiopia. Therefore, the present study was performed from October 2009 to May 2010 to determine the prevalence and species composition of mites in three agroecological zones in north eastern Ethiopia. In addition, a questionnaire survey on mites was conducted to assess the control practices and awareness of farmers in the study areas.

Results

Out of a total of 1280 sheep and 1264 goats examined, 97(7.6 %) of sheep and 174(13.8 %) goats were infested with one or more species of mites. In goats an overall prevalence of 10.3 % Sarcoptes, 2.8 % Demodex and 0.6 % Psoroptes were recorded whereas in sheep an overall prevalence of 3.5 % Sarcoptes, 2.1 % Demodex and 1.6 % Psoroptes were observed. Sarcoptes (P = 0.03; OR = 2.1) and Demodex (OR = 3.25; p = 0.004) were significantly more common in young than in adult sheep. Demodectic mange was significantly higher in young (4.1 %) compared to adult (2.3 %) goats (OR = 2.2; P = 0.02). Significantly higher (P < 0.01) overall prevalence of sarcoptic and demodectic mites in both sheep and goats with poor than with good body condition was recorded. Results of the questionnaire survey supported results of our cross-sectional study.

Conclusions

This study demonstrates high prevalence of mange mites in sheep and goats of the study area. The study revealed that Sarcoptes is the predominant mite in both sheep and goats. Animal owners and veterinarians should consider mite control in small ruminants as part of the routine ectoparasite control in Ethiopia.

Lice infesting horses in three agroecological zones in central Oromia

A cross-sectional study was conducted to determine the prevalence and species composition of lice infesting horses in three agroecological zones in seven different districts in central Oromia from November 2011 to April 2012. For this purpose, a total of 420 horses were thoroughly examined for presence of lice. Collected lice were identified to species level under a microscope. The study showed an overall prevalence of 28.8 % (121/420) lice infestation on horses. We identified two spp. of lice on horses namely, Bovicola (Werneckiella) equi and Haematopinus asini with an overall prevalence of 22.9 % (96/420) and 5.9 % (25/420), respectively. The overall prevalence of lice infestation on horses in districts was 48.3, 43.3, 33.3, 23.3, 21.7, 18.3 and 13.3 %, in Debre Brehan, Shashemene, Hawassa, Akaki, Adama, Modjo and Bishoftu, respectively. B. equi was encountered as the predominant species on horses in all districts. Higher overall prevalence of lice infestation was recorded in highland agroecology than mid and lowland agroecological zones. Similarly, our study revealed significantly higher overall prevalence of lice on saddle horses than on cart horses. In view of the findings of the present study two species of lice are responsible for health and welfare problems of horses in all the districts. Detailed epidemiological studies on the significance, prevalence and role of lice as vectors of zoonotic pathogens in different agroecological zones, breeds and management systems warrant urgent attention. Animal owners and veterinarians should consider lice control in horses as part of the ectoparasite control in other species of animals.

Internal parasites and health management of pigs in Burayu District, Oromia Regional State, Ethiopia

The study determined the prevalence and major types of gastrointestinal parasites in pigs and assessed the health management practices on farms in Burayu District in West Shoa Zone of Oromia Regional State, Ethiopia. The study was performed from November 2007 to April 2008 using standard coprological examination and a well-organised questionnaire survey. Of the 272 pigs examined for the presence of gastrointestinal parasites, 36 (13.2%) were infected with one or more types of parasite. Neither age nor management system proved to be a statistically significant factor in the prevalence of parasites. The highest prevalence of parasites was recorded in December, January and April, whereas the lowest was observed in February. Significant variation in the prevalence of parasites was noticed amongst study months. The majority of farmers did not use acaricides to treat and control external parasites. Anthelmintics were not used by any of the farmers. Some 76.1% of the farmers never used any type of treatment for sick pigs; 21.7% of the farmers used modern treatment and 2.2% of the farmers used traditional medicines. More than 95.0% of pigs were kept on soil floors and only 10.9% of the housing systems had good ventilation. Dung was removed at least every three days, with the majority of farmers (91.2%) removing it every morning. This study provided evidence for the occurrence of internal parasites in pigs kept in Burayu District in Oromia. Further epidemiological studies are needed to determine the zoonotic and economic importance of pig parasites in other parts of Ethiopia.

Hydatidosis of camel (Camelus dromedarius) at Jijiga municipal abattoir, Eastern Ethiopia: prevalence, associated risk factors and financial implication

A cross-sectional study was conducted from November 2010 to May 2011 to estimate the prevalence of camel hydatidosis, associated risk factors and financial loss in Jijiga municipal abattoir, Somali Regional State, Eastern Ethiopia. Accordingly, of the total 400 inspected camel, 92 (23 %) camels and 109 organs were positive for hydatid cyst with the highest proportion recorded in lung (56 %) followed by liver (33.9 %), spleen (7.3 %) and kidneys (2.8 %). The prevalence of hydatidosis significantly varied among age categories (P < 0.05), sex (P < 0.05) and body condition score (P < 0.05) of camels. Hence, there is higher likelihood for occurrence of camel hydatidosis among the older age groups (OR 1.8, 95 % CI 1.2, 3.3), in female camels (OR 2.8, 95 % CI 1.7, 4.7) and in poor body conditioned camels (OR 4.1, 95 % CI 2.2, 7.9) than younger camels, males and camels with good body condition score, respectively. Of the total 288 examined cysts for fertility and viability, 59.7 % (172/288) were fertile while the rest 24.0 % (69/288) cysts were sterile. Of the 172 fertile cysts 69.8 % (n = 120) were viable and 30.2 % (n = 52) were non-viable. The rest 16.3 % (47/288) cysts were found dead. It was also observed that the pulmonary and hepatic cysts had fertility rate of 63.7 % (116/182) and 57.4 % (54/94), respectively. The total annual direct financial loss recorded in this study as result of organs condemnation due to hydatid cyst, was 12,147.75 Ethiopian birrs ($714.57 or $7.77/camel). If this value could be extrapolated to the infected camel population of the region, financial loss due to hydatidosis could be enormous. In conclusion, this study showed the importance of hydatidosis and the associated direct financial loss due to the condemnation of organs affected by hydatid cyst in the study area.

Molecular detection of Rickettsia felis and Bartonella henselae in dog and cat fleas in Central Oromia, Ethiopia

Fleas are important vectors of several Rickettsia and Bartonella spp. that cause emerging zoonotic diseases worldwide. In this study, 303 fleas collected from domestic dogs and cats in Ethiopia and identified morphologically as Ctenocephalides felis felis, C. canis, Pulex irritans, and Echidnophaga gallinacea were tested for Rickettsia and Bartonella DNA by using molecular methods. Rickettsia felis was detected in 21% of fleas, primarily C. felis, with a similar prevalence in fleas from dogs and cats. A larger proportion of flea-infested dogs (69%) than cats (37%) harbored at least one C. felis infected with R. felis. Rickettsia typhi was not detected. Bartonella henselae DNA was detected in 6% (2 of 34) of C. felis collected from cats. Our study highlights the likelihood of human exposure to R. felis, an emerging agent of spotted fever, and B. henselae, the agent of cat-scratch disease, in urban areas in Ethiopia.

Molecular detection of piroplasms in ixodid ticks infesting cattle and sheep in western Oromia, Ethiopia

In Ethiopia, ticks and tick-borne diseases are widely distributed and contribute to important economic losses. Several studies investigated the prevalence and species composition of ticks infesting ruminants; however, data on tick-borne pathogens are still scarce. During the study period from October 2010 to April 2011, a total of 1,246 adult ticks and 264 nymphs were collected from 267 cattle and 45 sheep in Bako District, western Oromia, Ethiopia. The study showed infestation of 228/267 (85.4 %) cattle and 35/45 (77.8 %) sheep with adult ticks. Overall, eight tick species, belonging to three genera (Amblyomma, Rhipicephalus, Hyalomma), were identified and Amblyomma cohaerens (n = 577), Rhipicephalus evertsi evertsi (n = 290), Rhipicephalus (Boophilus) decoloratus (n = 287), and Amblyomma variegatum (n = 85) were the more prevalent species. A statistically significant host preference in A. cohaerens for cattle and R. evertsi evertsi for sheep was noticed. Molecular detection of piroplasms, performed only for adult ticks of two species of the genus Rhipicephalus (R. evertsi evertsi and R. decoloratus), revealed an overall prevalence of 4 % (8/202) Theileria buffeli/sergenti/orientalis, 0.5 % (1/202) Theileria velifera, and 2 % (4/202) Theileria ovis. The study showed that tick infestation prevalence is considerably high in both cattle and sheep of the area, but with a low intensity of tick burden and a moderate circulation of mildly pathogenic piroplasm species.

Molecular detection of Acinetobacter species in lice and keds of domestic animals in Oromia Regional State, Ethiopia

This study was conducted to determine the presence of Acinetobacter and Rickettsia species DNA in lice and Melophagus ovinus (sheep ked) of animals from Oromia Regional State in Ethiopia. From September through November 2011, a total of 207 cattle, 85 sheep, 47 dogs and 16 cats were examined for ectoparasites. Results of morphological identification revealed several species of ectoparasites: Linognathus vituli (L. vituli), Bovicola bovis (B. bovis) and Solenopotes capillatus (S. capillatus) on cattle; B. ovis and Melophagus ovinus (M. ovinus) on sheep; and Heterodoxus spiniger (H. spiniger) on dogs. There was a significantly (p≤0.0001) higher prevalence of L. vituli observed in cattle than both S. capillatus and B. bovis. Molecular identification of lice using an 18S rRNA gene analysis confirms the identified lice species by morphological methods. We detected different Acinetobacter species among lice (11.1%) and keds (86.4%) including A. soli in L. vituli of cattle, A. lowffii in M. ovinus of sheep, A. pittii in H. spiniger of dogs, 1 new Acinetobacter spp. in M. ovinus and 2 new Acinetobacter spp. in H. spiniger of dogs using partial rpoB gene sequence analysis. There was a significantly higher prevalence of Acinetobacter spp. in keds than in lice (p≤0.00001). Higher percentage of Acinetobacter spp. DNA was detected in H. spiniger than in both B. ovis and L. vituli (p≤0.00001). Carbapenemase resistance encoding genes for blaOXA-23, blaOXA-24, blaOXA-58, blaNDM-1 and blaOXA-51 were not found in any lice and keds. These findings suggest that synanthropic animals and their ectoparasites might increase the risk of human exposure to zoonotic pathogens and could be a source for Acinetobacter spp. infections in humans. However, additional epidemiological data are required to determine whether ectoparasites of animals can act as environmental reservoirs and play a role in spreading these bacteria to both animal and human hosts.

Ectoparasites of sheep in three agro-ecological zones in central Oromia, Ethiopia

A cross-sectional study was conducted to determine the prevalence and risk factors for ectoparasites infestation in sheep in three agro-ecological zones in central Oromia, Ethiopia, from October 2009 to April 2010. The study revealed that 637 (48.1%) of the 1325 sheep examined were infested with one or more ectoparasites. The ectoparasites identified were Bovicola ovis (27.2%), Melophagus ovinus (16.4%), Ctenocephalides sp. (2.3%), Linognathus africanus (1.2%), Linognathus ovillus (0.3%), Sarcoptes sp. (1.2%), Amblyomma variegatum (4.4%), Rhipicephalus evertsi evertsi (1.9%), Rhipicephalus pravus (1.9%), Rhipicephalus (Boophilus) decoloratus (1.1%), Rhipicephalus sanguineus (0.9%), Rhipicephalus praetextatus (1.1%) and Hyalomma truncatum (1.6%). Statistically significant difference was observed in prevalence of B. ovis amongst study agroecological zones: highland 36.6%, midland 20.9% and lowland 14.0%. Significantly higher prevalence was recorded in highland agroecological zone. A significantly (OR = 0.041, p &lt; 0.001) higher prevalence of M. ovinus in the highland (31.7%) than in both the lowland (0%) and midland (1.9%) was observed. The risk of tick infestation in the lowland and midland was 9.883 times and 13.988 times higher than the risk in the highland, respectively. A significantly higher prevalence of Ctenocephalides species was encountered in both the lowland (OR = 4.738, p = 0.011) and midland (OR = 8.078, p = 0.000) than in the highland agro-ecological zone. However, a significant difference (p = 0.191) amongst agro-ecological zones was not found for the prevalence of Linognathus and Sarcoptes species. Statistically significant variation (p &gt; 0.05) was never recorded in the prevalence of all the identified species of ectoparasites between male and female sheep hosts. However, a significantly (p = 0.006) higher prevalence of B. ovis was recorded between young and adult sheep. The risk of B. ovis infestation was 1.45 times higher in young than the adult sheep. Furthermore, a significantly (p &lt; 0.001) higher prevalence of M. ovinus, B. ovis and Sarcoptes sp. was found between sheep with poor and a good body condition. The ever increasing threat of ectoparasites on overall sheep productivity and tanning industry in Ethiopia warrants urgent control intervention. Further studies on the role of ectoparasites in transmission of diseases to sheep, zoonotic importance, comparative prevalence and load, and the importance of sheep as alternative hosts in different agroecological zones, breeds and management systems in Ethiopia are recommended so as to design applicable control programme in the country.

Hydatidosis of sheep and goats slaughtered at Addis Ababa Abattoir: prevalence and risk factors

Abattoir survey was conducted on 1,053 sheep and 639 goats slaughtered at Addis Ababa Abattoir, Ethiopia, between October 2007 and May 2008, with the objective to determine the prevalence of hydatidosis and assess the associated risk factors. Routine meat inspection procedure was employed to detect the presence of the cyst in visceral organs (lung, liver, and omentum). Hydatid cysts were found in 206 (19.94%) and 102 (16%) of the sheep and goats inspected, respectively. Statistically significant difference in infection rates was noted between the two species. Likewise, there was significant difference in infection rates between the two sexes and different age groups in both sheep and goats (P < 0.5). The study showed that hydatidosis is prevalent in Ethiopia. Thus, there is a need to introduce appropriate control measures to minimize the rate of infection and reduce the ensuing economic losses.

Synlophe structure in Pseudomarshallagia elongata (Nematoda: Trichostrongyloidea), abomasal parasites among Ethiopian ungulates, with consideration of other morphological attributes and differentiation within the Ostertagiinae

The independence of Pseudomarshallagia and its placement among the medium stomach worms of ungulates, Ostertagiinae, is confirmed based on comparative morphological studies of the synlophe and genital attributes among male and female specimens. An emended description of Pseudomarshallagia elongata is presented based on a series of specimens in sheep from northern Ethiopia. Pseudomarshallagia elongata is retained among the 15 genera of the Ostertagiinae based on presence of a prominent esophageal-intestinal valve, paired "0" papillae, a modified accessory bursal membrane containing the paired "7" papillae, and configuration of the copulatory bursa. The structure of the synlophe in males and females is also typical and within the range of variation demonstrated for Type II and Type A cervical patterns among other ostertagiines. We emphasize the importance of continued survey and inventory of parasite faunas to establish the limits of diversity on local, regional, and global scales. Consequently we strongly encourage routine deposition of voucher specimens from all survey activities designed to explore faunal diversity. Although this is particularly important in regions that remain poorly known, such as Africa, the principle certainly applies more broadly.

Multiple anthelmintic resistance on a goat farm in Hawassa (southern Ethiopia)

A study was conducted to determine the presence of anthelmintic resistance on Hawassa University goat farm in southern Ethiopia. The 180 goats were stratified by age and sex and randomly assigned to treatment groups (albendazole, tetramisole and ivermectin and untreated control). Each treatment group included 15 goats and treatments were administered according to weight of each goat with 7.5 mg/kg bw albendazole, 22.5 mg/kg bw tetramisole and 0.2 mg/kg bw ivermectin dose rates recommended by scientists. Faecal samples were collected on day 0 before treatment, and again on day 12 post treatment. Efficacy of all the drugs was assessed on day 12 post treatment by faecal egg count reduction test (FECRT). Multiple anthelmintic resistance in Haemonchus spp. against albendazole, tetramisole and ivermectin was recorded in all age categories of the goats. Likewise, Trichostrongylus/Teladorsagia spp. showed resistance against ivermectin. Coprocultures from all pre- and post-treatments revealed the predominance of Haemonchus spp. Resistance against anthelmintics is attributed to the high frequency of treatment and low dosage of treatment practices on the farm. Large scale studies, however, are needed to assess the current status of anthelmintic resistance against the most commonly used anthelmintics in different agroecology, species of animals and management systems in Ethiopia.

Bovine cysticercosis in cattle slaughtered at Awassa municipal abattoir, Ethiopia: prevalence, cyst viability, distribution and its public health implication

A cross-sectional study was conducted from October 2005 to April 2006 on bovine cysticercosis in cattle slaughtered at Awassa municipal abattoir with the objective of determining the prevalence of Taenia saginata cysticercosis, cyst viability, distribution and its public health implication. Questionnaire survey involving 120 respondents was also conducted on human taeniasis. A total of 400 carcasses were examined during the study period, of which 105 (26.25%) were infected with T. saginata metacestodes. From a total of 3200 samples inspected, 500 cysticerci were detected in 141 samples, of which 221 (44.2%) were alive. The anatomical distribution of cysticerci were 65 (29.2%) heart, 56 (25.3%) shoulder muscle, 59 (26.7%) masseter, 23 (10.4%) tongue, 12 (5.4%) diaphragm, three (1.4%) liver, two (0.9%) lung and one (0.5%) kidney samples. The prevalence varied significantly between local and crossbred animals (OR = 3.15, P < 0.05), but not varied between sex, age groups and origin of the animals. T. saginata taeniasis was a widespread public health problem in the town with an overall prevalence of 64.2% (77 of 120). The potential risk factors for disease contraction were raw meat consumption, religion and occupational risks. In conclusion, the study revealed high prevalence of T. saginata metacestodes throughout the edible organs together with existence of deep-rooted tradition of raw meat consumption. This may magnify the public health hazards of T. saginata in the study area. As a result, the disease deserves due attention to safeguard the public health and further promote beef industry in the country.