Seroprevalence and risk factors of Toxoplasma gondii infection in humans in East Hararghe Zone, Ethiopia.

A cross-sectional study was conducted from April 2013 to September 2013 to determine the seroprevalence and possible risk factors for human Toxplasma gondii infection in East Hararghe Zone, Ethiopia. Serum samples were analysed using direct agglutination test, and immunosorbent agglutination assay for detecting IgG (n = 354) and IgM (n = 167) T. gondii antibodies. The T. gondii IgG and IgM seroprevalences were 65·8% [95% confidence interval (CI) 60·62-70·75] and 8·98% (95% CI 5·11-14·38), respectively. Gender difference in IgG seroprevalence was not significant (P > 0·05), but 69·5% of adults exhibited an IgG seroresponse to T. gondii. Pregnant women showed 76·4% and 9·3% seropositivity to IgG and IgM antibodies, respectively. Multivariable logistic regression analysis identified the risk factors significantly associated with T. gondii seropositivity were district [odds ratio (OR) 2·24, 95% CI 1·25-4·01, P = 0·007], pipe water source (OR 6·70, 95% CI 2·70-16·64, P < 0·001), age, with adults (OR 4·32, 95% CI 1·91-9·75, P < 0·001), and keeping cats in the home (OR 2·01, 95% CI 1·11-3·65, P = 0·021). The high seroprevalence of toxoplasmosis in the human population in the study area and the corresponding level of IgM seropositivity may be indicative of reactivation or recent infection and further studies on the status of congenital toxoplasmosis in the study area merit consideration.

Seroepidemiology of Toxoplasma gondii infection in free-range chickens (Gallus domesticus) of Central Ethiopia.

We performed a seroepidemiological study of Toxoplasma gondii infection in free-range chickens from October 2012 to May 2013. We used cross-sectional two-stage cluster sampling to collect blood samples from wing veins of 601 chickens from central Ethiopia. T. gondii-specific antibodies were assayed by modified agglutination test (MAT). We collected information about risk factors by questionnaire and used univariable and multivariable logistic regression to assess risk factors. An overall seroprevalence of 30·5% [95% confidence interval (CI) 26·27-34·14] and 54·2% (95% CI 47·06-61·36) was found at animal- and flock-level, respectively. The MAT end titre of seropositive chickens (n = 183) were 1 : 60 in 46, 1 : 180 in 28, 1 : 540 in 29, ⩾1 : 1620 in 48, 1 : 6000 in 22, 1 : 18,000 in five, 1 : 54,000 in one, and ⩾1 : 162,000 in four. Animal-level risk factors identified using multivariable logistic regression model were: midland altitude [odds ratio (OR) 2·53, 95% CI 1·12-5·72], cross and exotic breeds (OR 3·17, 95% CI 1·39-7·23), increased age of chickens (OR 2·32, 95% CI 1·19-4·49), extensive management (OR 6·92, 95% CI 1·34-35·86) and the presence of cats (OR 2·08, 95% CI 1·20-3·61). Similarly, flock-level risk factors were midland altitude (OR 3·62, 95% CI 1·31-9·99) and the presence of cats (OR 1·19-4·94). The knowledge of the local people about the health risk of cats to humans and animals is poor. Housing and management of cats and chickens are also poor. The widespread presence of T. gondii infection in free-range chickens of Central Ethiopia provides suggestive evidence for the high level of contamination of the living environment of people with T. gondii oocysts. Meat from free-range chickens might be an important source of infection for humans. Altitude, breed, age, management and presence of cats are independent predictors of seropositivity. Education of farmers about toxoplasmosis and further studies to elucidate the burden of toxoplasmosis in animals and humans warrants consideration.

Molecular and biological characterization of first isolates of Hammondia hammondi from cats from Ethiopia.

Toxoplasma gondii oocysts are morphologically and antigenically similar to oocysts of another feline coccidian, Hammondia hammondi. The distinction between H. hammondi and T. gondii is important from an epidemiological perspective because all isolates of T. gondii are potentially pathogenic for humans and animals, whereas H. hammondi is not known to cause clinical disease in any naturally infected intermediate or definitive hosts. In the present report, H. hammondi (designated HhCatEt1 and HhCatEt2) oocysts were found microscopically in the feces of 2 of 36 feral domestic cats (Felis catus) from Addis Ababa, Ethiopia. Oocysts were orally infective to Swiss Webster and gamma interferon gene knockout mice; the inoculated mice developed tissue cysts in their muscles. Laboratory-raised cats fed mouse tissues of infected mice shed H. hammondi oocysts with a prepatent period of 5 days. The DNA extracted from sporulated oocysts reacted with H. hammondi-specific primers, and sequences were deposited in GenBank (accession nos. JX477424, and KC223619). This is the first report of isolation of H. hammondi from cats from the African continent.

Genetic diversity of Toxoplasma gondii isolates from Ethiopian feral cats.

Recent studies indicate greater genetic variability among isolates of Toxoplasma gondii worldwide than previously thought. However, there is no information on genetic diversity of T. gondii from any host in Ethiopia. In the present study, genotyping was performed on viable T. gondii isolates by bioassays in mice from tissues and feces of 27 cats from Ethiopia. Viable T. gondii was isolated from hearts of 26 cats, feces alone of 1 cat, and feces and tissues of 6 cats; in total there were 33 isolates. Genotyping was performed on DNA from cell-cultured derived T. gondii tachyzoites and by using 10 PCR-restriction fragment length polymorphism markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). Four genotypes were recognized, including ToxoDB #1 (Type II clonal, nine isolates), ToxoDB #2 (Type III, five isolates), Toxo DB #3 (Type II variant, ten isolates), and ToxoDB #20 (nine isolates). Of interest is the isolation of different genotypes from tissues and feces of two cats, suggesting re-infection or mixed strain T. gondii infection. These findings are of epidemiological significance with respect to shedding of oocysts by cats. This is the first report of genotyping of T. gondii from any host in Ethiopia.

An investigation into the seroprevalence of Toxoplasma gondii, Bartonella spp., feline immunodeficiency virus (FIV), and feline leukaemia virus (FeLV) in cats in Addis Ababa, Ethiopia.

Toxoplasma gondii and Bartonella spp. are zoonotic pathogens of cats. Feline immunodeficiency virus (FIV), and feline leukaemia virus (FeLV) are immunosuppressive viruses of cats that can affect T. gondii oocyst shedding. In this study, the prevalence of antibodies to T. gondii, Bartonella spp., FIV, as well as FeLV antigens were determined in sera from feral cats (Felis catus) from Addis Ababa, Ethiopia. Using the modified agglutination test, IgG antibodies to T. gondii were found in 41 (85.4%) of the 48 cats with titres of 1:25 in one, 1:50 in one, 1:200 in six, 1:400 in six, 1:800 in six, 1:1600 in eight, and 1:3200 in 13 cats. Toxoplasma gondii IgM antibodies were found in 11/46 cats tested by ELISA, suggesting recent infection. Antibodies to Bartonella spp. were found in five (11%) of 46 cats tested. Antibodies to FIV or FeLV antigen were not detected in any of the 41 cats tested. The results indicate a high prevalence of T. gondii and a low prevalence of Bartonella spp. infection in cats in Ethiopia.

Isolation of viable Toxoplasma gondii from tissues and feces of cats from Addis Ababa, Ethiopia.

Cats are important in the epidemiology of Toxoplasma gondii because they are the only hosts that excrete environmentally resistant oocysts in feces. In the present study, hearts, serum, and feces from 36 feral cats from Addis Ababa area, Ethiopia, were examined for T. gondii infection. Antibodies to T. gondii were determined with the modified agglutination test (MAT, cutoff 1:25); 33 cats were seropositive. Hearts of all 36 cats were homogenized, digested in pepsin, and bioassayed in mice. Feces were examined for T. gondii oocysts by bioassay in mice. Viable T. gondii was isolated from heart of 26 by bioassay in mice and from 25 seropositive and 1 seronegative cats. Toxoplasma gondii was isolated from feces (oocysts) by bioassay in mice. In total, viable T. gondii was isolated from 27 of the 36 cats, and these isolates were designated TgCatEt1 to TgCatEt27. The high prevalence of T. gondii oocysts in feces of 8 (19.4%) of 36 cats is of high epidemiologic significance. This is the first report of isolation of viable T. gondii from any host in Ethiopia.

Prevalence of Toxoplasma gondii from free-range chickens (Gallus domesticus) from Addis Ababa, Ethiopia.

Prevalence of Toxoplasma gondii in free-range chickens (Gallus domesticus) is a good indicator of the environmental contamination with oocysts because chickens become infected mainly by feeding from ground, feed, or soil contaminated with oocysts. The seroprevalence of T. gondii antibodies in 125 free-range chickens from the Addis Ababa, Ethiopia, was determined. Antibodies to T. gondii were assayed by the modified agglutination test; 48 of 125 (38.4%) chickens were seropositive, with titers of 1:5 in 14, 1:10 in 12, 1:20 in 14, 1: 40 in 3, 1: 80 in 1, 1:160 in 1, 1:320 in 1, and ≥1:640 in 2 chickens. The hearts of 115 chickens were bioassayed for T. gondii infection. Hearts of 72 seronegative (modified agglutination test [MAT] < 1:5) chickens were pooled in 4 groups (20 + 18 + 19 + 15) and fed to 4 T. gondii -free cats; none of these 4 cats shed oocysts in their feces examined 3-21 days after feeding chicken tissues. Hearts of 43 seropositive chickens (MAT ≥ 1:5) were bioassayed individually in mice. Toxoplasma gondii was isolated from only 1 chicken, with a MAT titer of 1:80. This isolate was designated TgCKEt1 and was not pathogenic for outbred mice. Restricted fragment length polymorphism (RFLP) genotyping using 10 loci indicated the TgCKEt1 was ToxoDB polymerase chain reaction-RFLP genotype #1 (Type II clonal). Results of this study indicate very low environmental contamination with T. gondii oocysts around Addis Ababa.

Prevalence and financial effects of hydatidosis in cattle slaughtered in Birre-Sheleko and Dangila Abattoirs, Northwestern Ethiopia.

A cross-sectional survey of bovine hydatidosis was carried out on local zebu cattle slaughtered at Birre-Sheleko and Dangila Abattoirs from August 2007 to July 2008 to determine the prevalence and to estimate financial loss caused by the disease. Postmortem examination, hydatid cyst characterization and direct and indirect financial loss estimations were conducted. Out of the total of 521 animals examined (255 Birre-Sheleko and 266 Dangila), 79 (15.2%) were found harbouring one or more hydatid cyst. The prevalence of the disease between the two abattoirs was not significantly different (P > 0.05). The result obtained from postmortem examination indicated that a total of 112 visceral organs were found harbouring one or more hydatid cysts. The involvement of lung, liver, spleen and kidney was found to be 70.5%, 21.4%, 6.3% and 1.8% respectively. From the total of 224 cysts counted, 147 (65.6%), 29 (12.9%), 3 (1.3%) and 45 (20.1%) were small, medium, large and calcified cysts respectively, and 114 (50.9%) and 65 (29%) were sterile and fertile cysts respectively. Viability rate of 47.7%, all from the lungs, and higher liver calcification rate were observed. The annual financial loss from organ condemnation and carcass weight loss due to bovine hydatidosis at Birre-Sheleko and Dangila abattoirs were estimated to be $18911.6.

Retrospective survey of human hydatidosis in Bahir Dar, north-western Ethiopia.

To determine the prevalence of human hydatidosis in Bahir Dar and the sex and age distribution and awareness, we used a questionnaire and retrospective analysis covering 5 years of the case reports at public health institutions in Bahir Dartown and the surrounding areas. We interviewed 244 individuals: 150 households, 32 abattoir workers, 30 butchers and 32 health professionals. None of the householders or butchers knew about cystic echinococcosis, nor did 25% of the health professionals; however, 100% of the abattoir workers and 75% of the health professionals recognized it. The householders owned on average 3 livestock and 1 dog and during holidays, ceremonies and other feasts, the community mostly practised backyard slaughter. Case book analysis between January 2002 and December 2006 showed that out of the total of 36,402 patients admitted for ultrasound examination, 24 hydatidosis cases were registered, giving a mean annual incidence rate of approximately 2.3 cases per 100,000 per year. Ultrasound was the most frequently used diagnostic method.

Retrospective survey of human hydatidosis in Bahir Dar, north-western Ethiopia

To determine the prevalence of human hydatidosis in Bahir Dar and the sex and age distribution and awareness, we used a questionnaire and retrospective analysis covering 5 years of the case reports at public health institutions in Bahir Dar town and the surrounding areas. We interviewed 244 individuals: 150 households, 32 abattoir workers, 30 butchers and 32 health professionals. None of the householders or butchers knew about cystic echinococcosis, nor did 25% of the health professionals; however, 100% of the abattoir workers and 75% of the health professionals recognized it. The householders owned on average 3 livestock and 1 dog and during holidays, ceremonies and other feasts, the community mostly practised backyard slaughter. Case book analysis between January 2002 and December 2006 showed that out of the total of 36 402 patients admitted for ultrasound examination, 24 hydatidosis cases were registered, giving a mean annual incidence rate of approximately 2.3 cases per 100 000 per year. Ultrasound was the most frequently used diagnostic method

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.

Seroprevalence of Toxoplasma gondii in Nazaret town, Ethiopia.

OBJECTIVE: To determine the seroprevalence of toxoplasmosis, assess its zoonotic importance and identify factors associated with seroprevalence. METHODS: Questionnaire survey was conducted on 65 serum samples collected from male and female urban and peri-urban residents aged between 15 days and 65 years. Main outcome measures were feeding habits, purpose of keeping cats and association with family members. Serologic evidence of toxoplasmosis was conducted by the Modified Direct Agglutination Test (MDA T) and determination of HIV status using the HIV - Spot Test. RESULTS: Over 50% of the interviewed people had a history of consumption of raw or undercooked mutton and had close contact with cats. 60% of the serum samples analyzed by the MDA T had serologic evidence of Toxoplasma infection. Significantly higher MDA T tiers were encountered both in pregnant and immunocompromised individuals. The risk factors associated to Toxoplasma infection, i.e. raw or undercooked mutton consumption and presence of cats appeared significant. CONCLUSION AND RECOMMENDATIONS: The significance of toxoplasmosis as a disease of zoonotic importance was demonstrated. Close contact between family members and the consumption of raw or undercooked mutton were the major risk factors in the transmission of the disease. Considering the relatively high prevalence as revealed by this study it would be important to conduct studies on a wider scale. It would also be important to increase public awareness and upgrade the knowledge on congenital toxoplasmosis.

Seroprevalence of Toxoplasma Ghondii in Nazareth Town; Ethiopia

Objective: To determine the seroprevalence of toxoplasmosis; assess its zoonotic importance and identify factors associated with seroprevalence. Methods: Questionnaire survey was conducted on 65 serum samples collected from male and female urban and peri-urban residents aged between 15 days and 65 years. Main outcome measures were feeding habits; purpose of keeping cats and association with family members. Serologic evidence of toxoplasmosis was conducted by the Modified Direct Agglutination Test (MDA T) and determination of HIV status using the HIV - Spot Test. Results: Over 50of the interviewed people had a history of consumption of raw or undercooked mutton and had close contact with cats. 60of the serum samples analyzed by the MDA T had serologic evidence of Toxoplasma infection. Significantly higher MDA T tiers were encoun- tered both in pregnant and immunocompromised individuals. The risk factors associated to Toxoplasma infection; i.e. raw or undercooked mutton consumption and presence of cats appeared significant. Conclusion and recommendations: The significance of toxoplasmosis as a disease of zoonotic importance was demonstrated. Close contact between family members and the consumption of raw or undercooked mutton were the major risk factors in the transmission of the disease. Considering the relatively high prevalence as revealed by this study it would be important to conduct studies on a wider scale. It would also be important to increase public awareness and upgrade the knowledge on congenital toxoplasmosis

Taeniasis and its socio-economic implication in Awassa town and its surroundings, Southern Ethiopia.

OBJECTIVE: The study was conducted between October 2005 and April 2006 in Awassa town and its surroundings to investigate the status of T. saginata taeniasis, its socio-economic importance and potential risk factors. METHODS: Questionnaire survey was conducted on 120 volunteer individuals selected at random. Additionally, retrospective study on taenicidal drugs inventories at 12 pharmaceutical shops was conducted. RESULTS: T. saginata taeniasis was a wide spread problem in the town and its surroundings with overall prevalence of 64.2% (77 out of 120) and maximum infection frequencies of five times per year. The prevalence of taeniasis was significantly varied between religion, occupation, raw meat consumption and use of spices with raw meat. Accordingly, Christian communities (OR = 5.2, 95% CI = 1.20-22.50), high-risk groups (OR = 4.05, 95% CI = 1.27-12.93), raw meat consumers (OR = 7.9, 95% CI = 2.46-5.66), and spices users (OR = 11.6, 95% CI = 2.85-47.28) had higher likelihood of acquiring taeniasis than Muslim communities, low risk groups, cooked meat eaters and non-spices users, respectively. Conversely, prevalence was not varied between sex, age, marital status and educational backgrounds of the respondents. Respondents' preferences to available taenicidal drugs had strong linear relationship with drug dose sold (R2 = 0.92), and showed that Niclosamide (46.8%) was the drug of first choice while Praziquantel (13%) was the least preferred drug. The taenicidal drug doses and treatment cost from 2002 to 2005 were estimated to be 4,913,346 adult doses and 820,343 USD (7,219,021 Eth. Birr as per rate of 2006). CONCLUSION: Taeniasis was a wide spread problem with higher prevalence and frequent infections in the town and its surroundings. Sociocultural conditions and occupation were the major risk factors for the occurrence of the disease. Hence, owing to its public health and economic importance, taeniasis deserves serious attention in order to safeguard the public health.

Haemonchus contortus: in vitro and in vivo anthelmintic activity of aqueous and hydro-alcoholic extracts of Hedera helix.

In vitro anthelmintic activity of crude extracts of the ripe fruits of Hedera helix was investigated on eggs and adult nematode parasites Haemonchus contortus. Aqueous extract of H. helix was also evaluated for in vivo anthelmintic activity at dose of 1.13 and 2.25 g/kg in sheep artificially infected with H. contortus. ED(50) for egg hatch inhibition was 0.12 and 0.17 mg/ml for aqueous and hydro-alcoholic extracts, respectively. There was no statistically significant difference in the activity of the two extract types (p>0.05). Hydro-alcoholic extract showed better in vitro activity against adult parasites compared to the aqueous extract. Significant faecal egg count reduction (FECR) was detected in groups treated with both doses of H. helix (p<0.05) on day 2 post-treatment. On day 7 post-treatment significant reduction was detected only for higher dose of H. helix (p<0.05) while on day 14 post-treatment there was no significant FECR in both groups treated with H. helix. The percentage of larvae recovered from culturing faeces obtained from groups of sheep treated with lower and higher doses of H. helix was 47.52% and 36.07%, respectively, which was significantly lower than (p<0.05) that recovered from the control group (60%). Significant (p<0.05), dose dependent total worm count reduction (WCR) was observed for groups of sheep treated with H. helix. Increasing the dose of H. helix improved the efficacy against the male than the female parasites. Treatment with both doses of H. helix helped the animals maintain their packed cell volume (PCV) unlike the untreated control group. The overall findings of the current study indicated that H. helix has a potential anthelmintic benefit and further in vitro and in vivo evaluation of the different parts and fractions is needed to make use of this plant for therapeutic purposes.

In vitro and in vivo anthelmintic activity of crude extracts of Coriandrum sativum against Haemonchus contortus.

In vitro anthelmintic activities of crude aqueous and hydro-alcoholic extracts of the seeds of Coriandrum sativum (Apiaceae) were investigated on the egg and adult nematode parasite Haemonchus contortus. The aqueous extract of Coriandrum sativum was also investigated for in vivo anthelmintic activity in sheep infected with Haemonchus contortus. Both extract types of Coriandrum sativum inhibited hatching of eggs completely at a concentration less than 0.5 mg/ml. ED(50) of aqueous extract of Coriandrum sativum was 0.12 mg/ml while that of hydro-alcoholic extract was 0.18 mg/ml. There was no statistically significant difference between aqueous and hydro-alcoholic extracts (p>0.05). The hydro-alcoholic extract showed better in vitro activity against adult parasites than the aqueous one. For the in vivo study, 24 sheep artificially infected with Haemonchus contortus were randomly divided into four groups of six animals each. The first two groups were treated with crude aqueous extract of Coriandrum sativum at 0.45 and 0.9 g/kg dose levels, the third group with albendazole at 3.8 mg/kg and the last group was left untreated. Efficacy was tested by faecal egg count reduction (FECR) and total worm count reduction (TWCR). On day 2 post treatment, significant FECR was detected in groups treated with higher dose of Coriandrum sativum (p<0.05) and albendazole (p<0.001). On days 7 and 14 post treatment, significant FECR was not detected for both doses of Coriandrum sativum (p>0.05). Significant (p<0.05) TWCR was detected only for higher dose of Coriandrum sativum compared to the untreated group. Reduction in male worms was higher than female worms. Treatment with both doses of Coriandrum sativum did not help the animals improve or maintain their PCV while those treated with albendazole showed significant increase in PCV (p<0.05).

Seroprevalence of Toxoplasma gondii in Nazareth Town, Ethiopia.

OBJECTIVE: To determine seroprevalence of toxoplasmosis, assess its zoonotic importance and identify factors associated with seroprevalence. DESIGN: Questionnaire survey and serological studies. SUBJECTS: Questionnaire survey and 65 serum samples from male and female urban and peri-urban residents aged between 15 days and 65 years. MAIN OUTCOME MEASURES: Feeding habits, purpose of keeping cats and association with family members, serologic evidence of toxoplasmosis by the Modified Direct Agglutination Test (MDAT), examination of HIV status using the HIV-Spot Test. RESULTS: Over 86% of the interviewed people had a history of consumption of raw or undercooked mutton and had close contact with cats. Of the serum samples analyzed by the MDAT 60% had serologic evidence of Toxoplasma infection. Significantly higher MDAT tiers were encountered both in pregnant and immunocompromised individuals. The risk factors associated with Toxoplasma infection, i.e. raw or undercooked mutton consumption and presence of cats appeared significant. CONCLUSION AND RECOMMENDATIONS: The significance of toxoplasmosis as a disease of zoonotic importance was demonstrated. Close contact between family members and the consumption of raw or undercooked mutton were the major risk factors in the transmission of the disease. Considering the relatively high prevalence as revealed by this study it would be important to conduct studies on a wider scale. It would also be important to increase public awareness and upgrade the knowledge on congenital toxoplasmosis.

Multiple-drug resistant Trypanosoma congolense populations in village cattle of Metekel district, north-west Ethiopia.

Investigations were carried out to determine the prophylactic activity of isometamidium chloride in village populations of cattle naturally infected with trypanosomes in Metekel district, northwest Ethiopia. In a cross-sectional study in March 1997, 484 randomly selected cattle from four villages were examined for trypanosome infections by the dark ground/phase contrast buffy coat technique (BCT). The trypanosome prevalence was 17.2%. Trypanosoma congolense was the dominant species accounting for 47.6% of the overall infections. Fifty parasitaemic cattle from two villages were treated with isometainidium chloride (Trypamidium(R)) at a prophylactic dose of 1.0 mg/kg body weight (b.w.) and thereafter monitored on a monthly basis for parasitaemia. Trypanosomes were detected in six cattle within 1 month and in 18 cattle within 2 months of treatment. Twenty three percent (6/26) of cattle infected with T. congolense at the time of treatment were detected parasitaemic with this trypanosome species 1 month after treatment. Mice were infected with three T. congolense isolates obtained from cattle which were detected parasitaemic within one or 2 months after isometamidium treatment. The mice were subsequently treated with ranges of doses of isometamidium chloride or diminazene aceturate (Berenil(R)) and thereafter monitored for parasitaemia for a period of 60 days. Isometamidium chloride at doses of 0.5-4.0 mg/kg b.w. and diminazene aceturate at doses of 3.5-28.0 mg/kg b.w. failed to cure T. congolense infections in any of the animals. Three clones were derived from one of the isolates; each clone expressed high levels of resistance to both trypanocides when tested in mice. Based on these results it is concluded that the prophylactic activity of isometamidium is greatly reduced for some of the T. congolense populations present in the area, and in addition there is resistance to diminazene aceturate in this trypanosome species.

Prevalence of bluetongue virus antibodies in sheep in central Ethiopia.

Competitive ELISA was applied to detect antibodies against bluetongue virus in sheep sera collected from different agro-climatic areas in Ethiopia. A total of 90 serum samples were tested and 42 (46.67%) were positive for bluetongue virus antibodies. A prevalence rate ranging from 9.67% for sheep sampled in the highland to 92.85% for sheep sampled in the lowland was recorded. The prevalence correlated with the probable distribution of the Culicoides vector. This is the first report indicating the presence of bluetongue virus infection in animals from Ethiopia.

Financial losses caused by ovine fasciolosis in the Ethiopian highlands.

An estimate of the economic loss due to ovine fasciolosis in the Ethiopian highlands was made based on available data on mortality, weight loss, reduced reproductive efficiency and liver condemnation at slaughter. The economic effects of fasciolosis were identified and models for estimating the financial loss presented. Ovine fasciolosis losses were estimated at 48.4 million Ethiopian Birr per year of which 46.5, 48.8 and 4.7% were due to mortality, productivity (weight loss and reproductive wastage) and liver condemnation, respectively. These losses can be reduced substantially by fasciolosis control programmes that may include the use of anthelmintics, grazing management and nutritional supplementation.