Microhaematocrit Centrifugation Technique Research Articles

Effect of Tick-Borne Haemoparasitic Diseases on Haematological Parameters of Small Ruminants Managed Under Semi-intensive System in Wukari Town Taraba State Nigeria

This study was conducted to determine the effect of tick-borne haemo-parasitic diseases on haematological parameters of small ruminants managed under semi-intensive system in Wukari town Taraba State, Nigeria. A total of 100 blood samples were collected from sheep (n = 50) and goats (n = 50) from February to March, 2023. Giemsa stained blood smears were prepared and examined under light microscope, to screen for haemo-parasites. Packed cell volume (PCV) was determined by microhaematocrit centrifugation technique while haemoglobin (Hb) concentration was determined by Sahli’s method. The total white blood cell (WBC) was estimated with Neubauer haemocytometer. The results showed 13% overall prevalence of tick-borne haemo-parasitic diseases. Prevalence based on specie of animal was higher in goats (16%) than in sheep (10%). Prevalence was observed higher in adults than the young, and there was significant difference between age and prevalence of the haemo-parasites. Sex-wise, prevalence of haemo parasites in both goats and sheep was significantly higher in females than males. Anaplasma infection was more prevalent than Babesia infection in both species of the animals examined. The mean values of PCV, Hb concentration of infected sheep were significantly (P<0.05) lower than the uninfected sheep. Similarly, the mean values of PCV and Hb concentration were significantly (p<0.05) lower in infected goats. This study has confirmed that tick-borne haemo-parasitic diseases cause anaemia in infected goats and sheep kept in the study area. We recommend tick control using suitable acaricides, periodic screening and treatment of small ruminants in the study area.

Molecular Detection and Characterization of Trypanosomes Infecting Traditionally Managed Cattle in the Tropic Warm Sub-Humid Zone of Nigeria

Abstract Traditionally managed cattle constitutes the main source of animal protein to humans in Nigeria. However, seasonal migration in search of pasture exposes them to several vector-borne infections such as the African Animal Trypanosomosis (AAT), which limits their productivity. In this study, blood samples from 130 cattle in Plateau and Nasarawa states collected from May to June, 2021 were examined by the Polymerase Chain Reaction (PCR) and sequencing methods to determine the prevalence of pathogenic trypanosomes. Overall, the DNA of T. vivax was detected in 19 out of the 130 (14.6 %) samples examined by the PCR. However, using the micro-hematocrit centrifugation technique, motile haemoparasites were detected in only six (4.6 %, confidence interval [CI] 0.5—6.9 %) of the samples. The higher prevalence of T. vivax was recorded in samples sourced from the abattoir than in samples submitted from the field in Plateau state (16.7 % versus 11.5 %). However, the reverse was the case in Nasarawa state (2.9 % versus 37.5 %). The difference in prevalence of T. vivax between the abattoir and field samples was significant (P = 0.009) in Nasarawa state, but not in Plateau state (P = 0.55). The mean PCV (Packed Cell Volume) of the trypanosome infected animals was lower than that of the non-infected animals, but the difference was not significant (P = 0.29). The internal transcribe spacer region (ITS) nucleotide sequences of T. vivax generated in this study were 100 % identical to each other and formed a monophyletic cluster with the sequences of T. vivax from different countries in the GenBank. AAT remains a major constraint to profitable cattle production and food security in Nigeria and deserves more attention.

Evaluasi Pemberian Obat Diminazene Aceturate Secara In Vivo Pada Mencit (Mus musculus) yang Diinfeksi Isolat Trypanosoma evansi

Abstract Surra's disease is caused by Trypanosoma evansi parasite has been established as one of the strategic infectious animal diseases. Drug resistance in this case is one of the major challenges in handle and control them. The aim of this study is to evaluate the provision drug resistance diminazene aceturate (Tryponil®) on Trypanosoma evansi isolate from Pemalang and Brebes Central Java province with in vivo test in mice. Total 50 mice, BALB / c strain, male, 2 months, body weight ± 30 gram are obtained from LPPT-UGM, adapted for one week. Mice were divided into 10 groups consist of 5 each. Each mouse was infected with Trypanosoma evansi by intraperitonial route. Treatment was given when mice had reached the level of parasitemia 108 – 109 trypanosoma / mL of blood this was predicted 24 hours post-infection (Eisler et al., 2001). The administration of the drug tryapanosidal was done intraperitonial with doses 1mg/kg, 3mg / kg, 5 mg / kg and 7mg / kg. Observation of parasitemia did every 2 times in one week till 60 days of observation. Parasitemia observation was performed using 3 techniques. The first method was native examination used a microscope, if the negative results would be followed by MHCT (Microhaematocrit centrifugation Technique) and BCT (Buffy Coat Technique) according to OIE (2012). Data obtained from the treatment group were the level of parasitemia, the number of deaths and the number of live mice from each test dose. The results are analysed by standard logit or probit. The results of this study showed the effects of the drug Dimianzene aceturate on both isolates varied. On Brebes Isolate was effective at doses of 7 mg / kg BW (100%) and 5mg / kg BW (80%), whereas in the effective dose Pemalang isolate at 3 mg dose / kg BW (80%), 5 and 7 mg / kg BW (100%). While at the lowest dose of 1 mg / kg obtained a level of effectiveness of 0% in both isolates. It could be concluded that both isolates have different pathogens and indicate resistance subpopulation to diminazene aceturate.Keywords : diminazene aceturate, in vivo, resistance, Trypanosoma evansi.

The Prevalence of Spirochaetes and other Haemoparasites in Small Ruminants Slaughtered at Abattoirs in Ilorin Kwara State, Nigeria

The aim of this study was to investigate the prevalence of spirochaetes and other haemoparasites in small ruminants. A total of two hundred blood samples were collected from the jugular vein of sheep and goats at slaughter. The Microhaematocrit centrifugation technique, direct wet blood mount, thin blood smear and thick blood smear techniques were used to detect the presence of motile and non-motile haemoparasites. Data obtained were analyzed using percentages and tabulations. One hundred and twelve representing 56.00% of the sampled small ruminants were positive for spirochaetes and other haemoparasites. Spirochaetes was the most prevalent haemoparasites followed by Anaplasma ovis, Babesia spp. and Trypanosoma brucei. Higher prevalence of haemoparasites infection were observed in goats (82.50%) compared to sheep (41.25%). Haemoparasites were more prevalent in small ruminants sourced from the southern part (78.00%) compared to those sourced from the northern part (54.00%) of Nigeria. Higher prevalence of spirochaetes and other haemoparasites was recorded in male than female. Some spirochaetes are zoonotic therefore, the possibility of its transmission to man exists with butchers and other abattoir workers been at risk of spirochaetosis. The role of ruminant types, sex of animals, and geographical locations in the epidemiology of spirochaetes and other haemoparasites infections in Nigeria is worthy of further investigations.

Prevalence of different trypanosomes in livestock in Blue Nile and West Kordofan States, Sudan

African animal trypanosomosis, transmitted cyclically by tsetse flies or mechanically by other biting flies, causes serious health problems in livestock. Although tsetse infestations have been observed in Blue Nile State in Sudan, tsetse was eradicated in West Kordofan in 1962, and no further studies have been carried out. Accordingly, in this study, we investigated the prevalence of trypanosomosis in cattle, sheep, and goats in Blue Nile and West Kordofan States, Sudan. This cross-sectional study was conducted using 70 cattle, 62 sheep, and 116 goats, and the microhematocrit centrifugation technique was used as a parasitological test. KIN-multispecies polymerase chain reaction (PCR) was used to detect Trypanozoon sp., Trypanosoma congolense, and T. vivax; RoTat 1.2 variable surface glycoprotein-specific PCR was used to detect T. evansi; and TviCatL PCR was used to specifically detect T. vivax. The seroprevalence of trypanosomosis was assessed using card agglutination tests CATT/ T. evansi. The parasitological prevalence rates were 4% (3/70) in cattle, 2% (1/62) in sheep, and 4% (5/116) in goats. The molecular prevalence rates of T. vivax, the most prevalent parasite, were 99% (69/70) in cattle, 98% (61/62) in sheep, and 84% (98/116) in goats. Trypanozoon (T. evansi or T. brucie) rates were 30% (21/70) in cattle, 32% (20/62) in sheep, and 12% (14/116) in goats. Among Trypanozoon-positive isolates, T. evansi was confirmed in 24% (5/21) of cattle, 70% (14/20) of sheep, and 86% (12/14) of goats. Finally, T. congolense was recorded only in cattle in Blue Nile State, with a prevalence of 14% (10/70). The seroprevalence rates of CATT/T. evansi were 46% (32/70) in cattle, 45% (28/62) in sheep, and 14% (16/116) in goats. Thus, we confirmed molecularly, for the first time, the presence of Trypanozoon, particularly T. evansi and T. vivax, in sheep and goats in Sudan. Our results show that sheep and goats could be an important reservoir for trypanosomes, potentially leading to the spread of the disease to the northern parts of the country following the movement of these animals. These findings provide important insights into the epidemiology of the disease and could affect the establishment of control strategies against trypanosomosis in Sudan.

EVALUATION OF THE CARD AGGLUTINATION TEST (CATT/T. EVANSI) IN COMPARISON WITH PCR FOR DETECTION OF TRYPANOSOMA EVANSI INFECTION IN DONKEYS IN EGYPT

This study was initiated to evaluated CATT test in comparison with PCR for detection of Trypanosoma evansi infection in donkeys in Egypt. Six donkeys free from T. evansi were inoculated with T. evansi strain (Egypt CD2) which had been isolated from naturally infected horse. Parasitological examination of the donkeys revealed a prepatent period of T. evansi 1- 4 DPI. Two blood samples (heparinized and plain) were taken from each donkey every 4 days starting from day 0 until the end of the experiment for serological examination (CATT/ T. evansi). Body temperature was also estimated. Serological examination of the experimentally inoculated donkeys' no.1, 2, 4 and 5 showed that seroconversion occurred on 12 DPI and remained until death of animals. Other experiment, blood samples from 416 donkeys collected randomly from different governorates of Egypt, they were tested parasitologically (stained blood smear, mice inoculation (MI) and microhaematocrit centrifugation technique (MHCT) and serologically by using CATT/ T. evansi for diagnosis T. evansi infection. From the previous animals, 26 parasitologically negative donkeys were used for comparison between the resultsobtained by CATT/T. evansi & PCR techniques. Of 26 parasitologically negative samples, 9 (34.6%) & 14(53.85%) samples were found positive by using CATT and PCR techniques respectively. Despite of the simplicity and low-coast of CATT test, it is recommended to use it in combination with PCR technique for accurate and reliable results.

Field investigation and comparative evaluation of diagnostic tests of Trypanosoma evansi in camels in Egypt

Trypanosomosis is a chronic disease of camels caused by Trypanosoma evansi which is transmitted mechanically by Tabanus and Stomoxys spp. It has a worldwide distribution. In the present study, 259 male camels admitted to Kom-Hammada abattoir, Behera province were examined parasitologically for presence of T.evansi by Giemsa stained blood smears (GSBS), microhaematocrit centrifugation technique (MHCT) and polymerase chain reaction (PCR). The study revealed that total prevalence of T.evansi was 0.68% (2/295) using GSBS and 0.96% (2/209) using MHCT. While molecular examination of 100 samples by PCR gave a prevalence of 63%. Our results revealed that, using of PCR technique in diagnosis of trypanosomosis is more sensitive and specific especially in low infection rate cases as well as it is of potential role in epidemiological studies.

Identification of Blood Parasite on Sacrifical Cattle Slaughtered during Idul Adha 1438 H in Surabaya City and Sidoarjo Regency

The aim of this research is to detect the presence of blood parasite that infects sacrificial cattle slaughtered during idul adha 1438 H in Surabaya City and Sidoarjo Regency. This research used 147 blood samples of sacrificial cattle and used two methods, those are thin blood smear stained with Giemsa 20% and Microhematocrit Centrifugation Technique. Based on the result of the examination using a microscope with 1000x magnification, there are positive samples infected with blood parasite, that consist of Babesia sp., and Anaplasma sp.

Molecular diagnosis of acute and chronic infection of Trypanosoma evansi in experimental male and female mice.

Trypanosoma evansi is enzootic in camels in Egypt, and water buffaloes act as a reservoir for camel infection. Molecular techniques have contributed towards understanding the epidemiology of T. evansi. Trypanosoma evansi was detected in acute and chronic stages of the disease in male and female mice by polymerase chain reaction (PCR) using two primers. Two experiments were conducted. In experiment I, two groups consisting of 26 female and 26 male mice received 104 trypanosome by I/P inoculation for each mouse. In experiment II, 42 female and 42 male mice were inoculated I/P with 102 trypanosome/mouse. In addition, five mice were kept as uninfected control for each group. Mice were monitored daily for parasitaemia level during the pre-patent period using the micro-haematocrit centrifugation technique (MHCT) and conventional PCR. The primer pairs, (Trypanosoma brucei) TBR1/2 and TeRoTat1.2 (T. evansi Rode Trypanozoon antigen type [RoTat] 1.2), detected the infection after 24 hours earlier than MHCT in both experiments. The course of infection that was detected by MHCT revealed three waves of parasitaemia in female mice and two waves in male mice in the chronic stage of infection. In addition, PCR was able to detect T. evansi in different organs in the chronic stage (i.e. disappearance of parasite from blood). Application of the two primer sets on blood samples from camels showed that all samples were positive by TBR1/2 primers and only 32 of 44 were positive by TeRoTat1.2 primers. Acutely and chronically Trypanosoma-infected mice were detected by PCR in blood and organs. TBR1/2 primers were more sensitive than TeRoTat1.2 primers in detecting Trypanosoma-infected mice, and more reliable in detecting field-infected camels and excluding carrier animals.

Prevalence of bovine trypanasomosis in Katsina Central Abattoir, Katsina State

Trypanosomosis remains one of the major constraints to health and agricultural development in Nigeria and sub- Saharan Africa. Bovine (cattles) plays a major role in the investment of most famers in Nigeria, mainly for provision of animal protein and income. The output of this animal is disturbed by tsetse fly (Glossina spp) infestation which is the primary vector of trypanosome. This study was aimed to determining the species of trypanosome prevalent in Katsina Central Abattoir and their infection rates among breeds of Cattle. Two hundred and seven (200) cattle were sampled, wet, thin; thick films, giemsa staining technique, Micro Haematocrit Centrifugation Technique (MHCT) and Buffy Coat Technique (BCT) methods were used to detect trypanosomes present in the blood of the animals. Among the sample analyzed 3(1.5%) were positive for Trypanosome infection. The infection rates among the cattle breeds were; White Fulani 2(1%), Sokoto Gudali 1(0.5%), Red Bororo 0(0%) and Ketouko 0(0%). The species of Trypanosome found to be present were Trypanosoma vivax (1%) Trypanosoma congolense 1(0.5%) while Trypanosoma brucei (0%). Therefore trypanosome is prevalent in Katsina Central Abattoir even though the prevalence is low.Keywords: Buffy Coat Technique (BCT); MHCT; trypanosome; bovine; prevalence.

Parasitological and Molecular Detection of Canine Trypanosomiasis From Riyadh Province, Saudi Arabia.

Trypanosoma evansi is the most widespread of the pathogenic salivarian trypanosomes; it causes a serious disease called surra that affects domestic animals such as camels, horses, and dogs, and often leads to reduced productivity and economic losses. Therefore, the objectives of the present study were to determine the prevalence rates of trypanosomiasis using 3 parasitological tests (wet blood film, Giemsa staining, and microhematocrit centrifugation technique) and polymerase chain reaction (PCR) among stray dogs from Riyadh Province, Saudi Arabia. In the current study, 117 dog blood samples collected from certain districts of Riyadh Province showed that 5 of 117 dogs (4.3%) were positive for the genus Trypanosoma. In addition, the findings indicated no effect of dog gender or age on parasite infection. For a more specific diagnosis, PCR amplification of the RoTat 1.2 VSG gene in 5 internal transcribed spacer1-positive samples diagnosed with Trypanosoma indicated that 2 were positive for RoTat 1.2 T. evansi. The absence of the RoTat 1.2 VSG gene in 3 of the 5 T. evansi-positive samples could be explained by the circulation of T. evansi type B in dogs from Saudi Arabia. Thus, this is the first study demonstrating T. evansi type B outside of Africa.

English

A preliminary survey was conducted to determine the prevalence of some tick-borne haemoparasitic diseases (TBHDs) and their effects on the haematological parameters of sheep and goats in Maiduguri abattoir. A total of 200 blood samples were collected from sheep (n = 100) and goats (n = 100) from November 2015 to May 2016. Giemsa stained blood smears were prepared and examined under light microscope, to screen for haemoparasites. Packed cell volume (PCV) was determined by microhaematocrit centrifugation technique while haemoglobin (Hb) concentration was determined by Sahli’s method. The total white blood cell (WBC) and red blood cell (RBC) counts were estimated with Neubauer hemocytometer while erythrocyte indices were calculated. The results showed 13.5% overall prevalence of tick-borne haemoparasitic diseases in sheep 13 (6.5%) and goats 14 (7.0%). There was no significant (p>0.05) differences in prevalence of haemoparasites between sexes and age groups of sheep and goats. Anaplasma ovis and Babesia ovis were identified in the study of which A. ovis [23 (11.5%)] was higher (p<0.05) than B. ovis [2 (1.0%)]. A single co-infection of A. ovis and B. ovis was encountered in sheep. The mean values of PCV, Hb and RBC counts of infected sheep were lower (p<0.05) than the uninfected sheep. Similarly, the mean values of Hb and WBC of were significantly (p<0.05) lower in infected goats. This stud has reports important tick-borne haemoparasitic diseases in sheep and goats. We recommend tick control using suitable acaricides, periodic screening and treatment of small ruminants in Maiduguri. Key words: Anaemia, Anaplasma ovis, Babesia ovis, haemoglobin, packed cell volume, white blood cell count.

Trypanosoma vivax is the second leading cause of camel trypanosomosis in Sudan after Trypanosoma evansi

BackgroundThis study was conducted in response to recurring reports from eastern Sudan of camel trypanosomosis that can no longer be treated by currently available trypanocidal drugs. One hundred and eighty-nine blood samples were obtained from camels in different herds and local markets in the western part of Sudan, and a cross-sectional study was carried out between December 2015 and February 2016 to identify the causative agents and possible circulating genotypes.ResultsThe prevalence of trypanosomes detected using the conventional parasitological techniques of Giemsa-stained blood smears, wet blood smears and the microhematocrit centrifugation technique (MHCT) was 7% (13/189), 11% (21/189) and 19% (36/189), respectively. However, a multi-species KIN-PCR targeting the ITS region revealed that the prevalence of Trypanosoma evansi was 37% (70/189), while that of T. vivax was 25% (47/189). Consequently, we used a T. evansi-specific PCR (RoTat1.2 VSG gene) to analyse the KIN-PCR-positive samples and a T. vivax-specific PCR (Cathepsin L-like gene) to analyse all of the samples. The prevalence of T. evansi was 59% (41/70), while the prevalence of T. vivax was 31% (59/189). Mixed infections were detected in 18% (34/189) of the samples. These results were further confirmed by sequencing and a phylogenetic analysis of the complete internal transcribed spacer (ITS) region of T. evansi and the TviCatL gene of T. vivax.ConclusionWe conclude that T. vivax was newly introduced to the camel population and that T. evansi is no longer the single cause of camel trypanosomosis in Sudan. The presence of T. vivax in camels detected in this study is a challenge in the choice of diagnostic approaches, particularly serology, and PCRs. However, an analysis of drug resistance should be performed, and the genotypic variation should be verified. To our knowledge, this is the first molecular study on T. vivax and mixed-infection with T. vivax and T. evansi in Sudanese camels.

Comparison of three methods for diagnosis of Trypanosoma (Duttonella) vivax in cattle

Detection of Trypanosoma vivax in cattle is based on parasitological, serological and molecular methods. The aim of this study was to compare three different methods for detecting T. vivax during an outbreak of trypanosomiasis in southeast Brazil. Blood samples were collected from seventy-two animals to perform micro-hematocrit centrifugation technique (MHCT), indirect fluorescent antibody (IFAT), and polymerase chain reaction (PCR). A total of 84.72% (61/72) of the samples yielded a positive result in at least one test. The PCR test yielded the highest number of positives [73.6% (53/72)], followed by the IFAT [61.1% (44/72)] and MHCT [29.0% (21/72)]. Agreement among the three methods, as expressed by the kappa value, was poor. PCR proved to be the most sensitive of the three methods by demonstrating the highest positivity rate, even in the presence of low parasite levels. This work presents the first study comparing three different detection tests, to T. vivax, analyzing a relatively large-scale number of samples

English

This study was conducted to determine the prevalence of haemoparasites and some haematological parameters of slaughtered trade cattle in Maiduguri abattoir. A total of 120 blood samples were randomly collected from cattle between January and July, 2014. The samples were screened for haemoparasites by examining Giemsa stained thin blood films. Microhaematocrit centrifugation technique was used for determination of packed cell volume (PCV) while total red blood cell (RBC) counts and total white blood cell (WBC) counts were determined by cyanmethaemoglobin and hemocytometer methods. An overall prevalence of 10.8% (CI=0.064, 0.017) was recorded for Anaplasma (5.8%), Babesia (4.2%) and Trypanosoma species (0.8%). Young cattle had significantly (p<0.05) higher prevalence of 9.2% (CI= 0.052, 0.157) compared to adults with 1.7% (CI= 0.005, 0.059). Among different sexes, females had a significantly (p<0.05) higher prevalence of 7.5% (CI: 0.040-0.136) than males with 3.3% (CI= 0.130, 0.083). Rahaji breed had a significantly higher (p<0.05) prevalence of 7.5% (CI= 0.040, 0.136) compared to Ambala with 1.7% (CI= 0.005, 0.059), Kuri and Adamawa gudali each with a prevalence of 0.8% (CI= 0.002, 0.046). Cattle with moderate body condition scores had significantly (p<0.05) higher prevalence of 6.7% (CI= 0.034, 0.126) compared with those that have good body condition scores with 4.2% (CI= 0.018, 0.094) while thin and fat cattle were not infected with haemoparasites. Even though all the haematological parameters were within range of normal values, there was a significant difference (p<0.05) in mean packed cell volume (PCV) and total white blood cell (WBC) counts between infected and un-infected slaughtered cattle. It was concluded from this study that haemoparasites are endemic in cattle populations in Maiduguri and the prevalence of haemoparasites may be associated with changes in PCV and WBC count. Key words: Haematological parameters, haemoparasites, Maiduguri, Prevalence, risk factors, trade cattle.

Canine Trypanosomosis in the University of Nigeria Veterinary Teaching Hospital (UNVTH), Enugu State, Nigeria, Sub-Saharan Africa

Trypanosomosis is an insect-borne protozoan disease and a serious constraint to livestock production. The incidence of this disease in dogs at the University of Nigeria Veterinary Teaching Hospital (UNNVTH) has not been reported. This study is designed to determine the incidence of canine trypanomosis presented to the (UNNVTH) between June to August, 1998. The incidence of trypanosome species infecting dogs was also determined. Standard trypanosome detection methods comprising of wet blood films, thin films and microhaematocrit centrifugation technique were used; while the degree of anemia was determined through the use of FAMACHA eye color chart and packed cell volume (PCV) values. Results indicate that of the 55 dogs, fifteen (15) were confirmed infected. The highest incidence was recorded in July (54%) whilst those of June and August were 19% each. Of the species of trypanosomes isolated, all but one Trypanososma congelense were Trypanosoma brucei. All the infections were associated with anaemia. There is a significant difference (PKey words: Canine trypanosomosis, dogs, Nigeria, Nsukka, Trypanosoma brucei, Trypanosoma congelense.

Presence of Trypanosome Species and Anemic Status of Dogs in Zuru, Nigeria

Abstract The aim of this research is to study the presence and prevalence of trypanosome species in local dogs between January and July, 2010 in the Zuru area of Kebbi State, Nigeria.Standard trypanosome detection methods comprising of wet blood films, thin films and microhaematocrit centrifugation technique were used to detect trypanosomes; while the degree of anemia was determined through the use of FAMACHA® eye colour chart and packed cell volume values. A total of 567 dogs were enumerated in fourteen locations within the study area out of which 192 (33.7%) were randomly examined and 4 (2.08%) were positive for the presence of trypanosomes. All positive samples morphologically belong to the Trypanosoma brucei group. The obtained PCV values showed that 50 (26.04%) dogs were anemic, while the FAMACHA® detected anemia status of varying degrees in 104 (77%) sampled dogs.These findings are significant as this is the first time that the trypanosome infection will be reported in dogs from the study area. This study establishes the presence of Trypanosoma brucei group in the study area, which is of zoonotic and economic importance.

Epidemiology of Trypanosoma evansi and Trypanosoma vivax in domestic animals from selected districts of Tigray and Afar regions, Northern Ethiopia.

BackgroundAfrican animal trypanosomosis, transmitted cyclically by tsetse flies or mechanically by other biting flies, causes serious inflictions to livestock health. This study investigates the extent of non-tsetse transmitted animal trypanosomosis (NTTAT) by Trypanosoma (T.) evansi and T. vivax in domestic animals in the tsetse-free regions of Northern Ethiopia, Afar and Tigray.MethodsA cross sectional study was conducted on 754 dromedary camels, 493 cattle, 264 goats, 181 sheep, 84 donkeys, 25 horses and 10 mules. The microhaematocrit centrifugation technique was used as parasitological test. Plasma was collected for serodiagnosis with CATT/T.evansi and RoTat 1.2 immune trypanolysis (ITL) while buffy coat specimens were collected for molecular diagnosis with T. evansi type A specific RoTat 1.2 PCR, T. evansi type B specific EVAB PCR and T. vivax specific TvPRAC PCR.ResultsThe parasitological prevalence was 4.7% in Tigray and 2.7% in Afar and significantly higher (z = 2.53, p = 0.011) in cattle (7.3%) than in the other hosts. Seroprevalence in CATT/T.evansi was 24.6% in Tigray and 13.9% in Afar and was significantly higher (z = 9.39, p < 0.001) in cattle (37.3%) than in the other hosts. On the other hand, seroprevalence assessed by ITL was only 1.9% suggesting cross reaction of CATT/T.evansi with T. vivax or other trypanosome infections. Molecular prevalence of T. evansi type A was 8.0% in Tigray and in Afar and varied from 28.0% in horses to 2.2% in sheep. It was also significantly higher (p < 0.001) in camel (11.7%) than in cattle (6.1%), donkey (6%), goat (3.8%), and sheep (2.2%). Four camels were positive for T. evansi type B. Molecular prevalence of T. vivax was 3.0% and was similar in Tigray and Afar. It didn’t differ significantly among the host species except that it was not detected in horses and mules.ConclusionsNTTAT caused by T. vivax and T. evansi, is an important threat to animal health in Tigray and Afar. For the first time, we confirm the presence of T. evansi type B in Ethiopian camels. Unexplained results obtained with the current diagnostic tests in bovines warrant particular efforts to isolate and characterise trypanosome strains that circulate in Northern Ethiopia.

Prevalence of canine trypanosomiasis in certain areas of Andhra Pradesh.

A total of 937 dogs were screened for Trypanosoma evansi infection by wet blood film, blood smear staining techniques and micro haematocrit centrifugation technique (MHCT). In the present study, 2.28% of male dogs and 2.40% of female dogs were found positive by MHCT method. The findings indicated that there was no effect of T. evansi infection on sex of dogs. Higher prevalence of T. evansi infection was observed in Mongrel than in Pomeranian, Cross breeds, German Shepherd, Doberman and Labrador breeds. Age wise prevalence of T. evansi infection in dogs revealed that younger ones, below the 2years age group recorded the highest prevalence than the above the 2years age group dogs.

Trypanosoma evansi: A clinical, parasitological and immunological evaluation of trypanosomosis using a chronic rabbit model

We evaluated the clinical, parasitological and immunological effects of a Venezuelan strain of Trypanosoma evansi (T. evansi) throughout in experimentally inoculated rabbits over the course of infection and compared them with the same aspect in healthy animals. Body temperature was recorded in degrees Celsius, animal weight in kilograms, serum proteins in g/dl using a refractometer, haematocrit percentage by capillary centrifugation and the anti-T. evansi IgG titer by indirect ELISA immunoassay, from both infected animals and controls for 95 days. Infected animals showed a higher body temperature, total serum protein and anti- T. evansi antibody titer, and a lower haematocrit and weight gain than controls. These differences were related to the presence of the parasites in the blood as detected micro-haematocrit centrifugation technique (MHCT) and direct microscopic examination (DME). This study confirms the usefulness of rabbits as a model for the study of trypanosomosis; the clinical features of the disease can be observed and the three characteristic stages, prepatent period, acute and chronic phase clearly defined over the course of the infection