Erratum to: A cross-sectional study on bovine tuberculosis in Hawassa town and its surroundings,Southern Ethiopia

Tropical Animal Health and Production -     

Status of bovine tuberculosis and its zoonotic implications in Borana zone,Southern Ethiopia

A cross-sectional study was carried out from April 2015 to June 2016 to estimate the status of bovine tuberculosis (BTB), assessment of community’s current knowledge, and zoonotic importance on this disease in Borana zone, southern Ethiopia. In this study, comparative intradermal tuberculin (CIDT) test, structured questionnaires, and retrospective data were used, while the result indicated 3.8% prevalence at individual animal level with 5.6% (31/554) of doubtful reactors. Among related risk factors included, old animals were significantly infected by BTB than young one (χ ²?=?32.005, P?=?0.001). Parity number again showed significant difference (χ ²?=?29.163, P?=?0.001) where animals with many parity were more reactive to conducted test than few parity numbers. Animals born in the breeding center managed under semi-intensive production system were more infected (χ ²?=?10.795, P?=?0.029) than those brought from outside of the center. Questionnaire survey in this study indicated that out of 130 interviewed respondents, only 30% pastoralists knew what BTB mean; whereas the level of individual knowledge from interviewed showed about 72.3% of respondents had poor understanding of BTB and only about 11.5% of them knew its zoonotic importance. Meat eating habit of communities in the area were culturally inhabited to eat cooked meat and only 12.3% (16/130) of respondents gave response on habit of eating both raw and cooked meat. Milk drinking habit of pastoralist in the area showed about 79.2% drunk raw milk and the rest 20.8% used both raw and boiled milk. A retrospective data from Yabello Hospital indicated that current prevalence of human TB as 38.79% and showing the disease was highly increasing from year to year in the study area. This implies a great importance of human tuberculosis and its future concern in Borana zone. From this, there should be detail awareness of communities on BTB, its zoonotic importance, and the need of further investigation to develop control and prevention strategies according to the pastoral settings.     

Major causes of mastitis and associated risk factors in smallholder dairy farms in and around Hawassa, Southern Ethiopia

A cross-sectional study was carried out from October 2008 to May 2009 in smallholder dairy farms in and around Hawassa to estimate the prevalence of mastitis, to isolate and characterize major bacterial pathogens, and to identify possible associated factors. The study involved a total of 201 milking cows randomly drawn from smallholder farms. The prevalence of clinical and subclinical mastitis was determined through clinical examination of the udder and using mastitis indicator paper (Bovivet indicator paper, Kruuse, Denmark). The prevalence of mastitis at cow and quarter level was 30.3 (61/201) and 10.3 (79/766), respectively. Subclinical mastitis was 25.4% and 5.0% was clinical. Stage of lactation significantly affected (P < 0.05) the prevalence of mastitis, with the highest prevalence observed in the late stage of lactation (41.3%) as compared to early (25.0%) and mid (22.1%) stages of lactation. Floor type and bedding had association (P < 0.05) with mastitis prevalence. Cows housed in concrete-floored houses had lower prevalence (19.0%) of mastitis compared to cows kept in soil-floored houses (47.6%). Mastitis prevalence was low in farms which do not use bedding (23.5%) as compared to farms using hay/straw bedding (37.4%). However, age, parity, and history of mastitis had no association (P > 0.05) on the prevalence of mastitis. The pathogens isolated from mastitic cows were Staphylococcus aureus (48.6%), other staphylococci species (15.7%), Streptococcus agalactiae (11.4%), other streptococci (17.1%), Bacillus species (2.9%), and coliforms (Escherichia coli and Klebsiella species) (4.3%). Strict hygienic measure of housing and bedding should be considered, in reducing the prevalence of mastitis.     

Prevalence study on bovine tuberculosis and molecular characterization of its causative agents in cattle slaughtered at Addis Ababa municipal abattoir, Central Ethiopia

A cross-sectional study was conducted on 500 cattle slaughtered at Addis Ababa abattoir to determine the prevalence of bovine tuberculosis (BTB) and characterize its causative agents. Postmortem examination, mycobacteriological culturing, region of difference-4 (RD4)-based PCR and spoligotyping were applied. The prevalence of BTB was 5 % on the basis of postmortem inspection alone but 1.2 % based on molecular confirmation. Factors including age, sex, and breed showed statistically significant association with BTB (p?<?0.05). Gross lesions were observed most frequently (68 %) in the lungs and lung-associated lymph nodes compared to other organs and lymph nodes. Of the 25 grossly suspicious TB lesions processed and cultured, only six (24 %) were culture-positive, yielding Mycobacterium bovis confirmed by RD4 deletion typing. Further characterization of the six M. bovis isolates at the strain level by using spoligotyping revealed that one did not belong to any previously known type, while the others belonged to types SB1176 (two), SB1477 (two), and SB0133 (one). The new strain was submitted to the international M. Bovis.org database for international code designation. The study confirms the considerable prevalence of bovine tuberculosis in cattle slaughtered at Addis Ababa abattoir and highlights the need for control of bovine tuberculosis in the country.     

Study on the prevalence of cystic hydatidosis and its economic significance in cattle slaughtered at Hawassa Municipal abattoir,Ethiopia

A cross-sectional study was conducted from December 2008 to March 2009 to assess the status of cystic hydatidosis in cattle slaughtered at Hawassa Municipal abattoir. Out of the total 632 cattle examined visually and manually (palpation and incision), 333 (52.69%) were found harboring hydatid cysts. A significantly higher infection was detected in older cattle (P < 0.05, χ ² = 4.36) than young. Regarding body condition score, no significant variation (P > 0.05, χ ² = 2.148) was observed as the prevalence was 54.55% for lean cattle followed by medium (53.83%) and fat (46.88%). Of the total 333 infected, 123 (36.9%) had hydatid cysts only in the lung, 23 (6.9%) in the liver, 12 (3.6%) in the spleen, five (1.5%) in the heart, and three (0.9%) in the kidney while the rest 167 (50.2%) had multiple organ infections. Of the 530 viscera harboring hydatid cysts, the highest (52.83%) was lung followed by liver (34.15%), spleen (9.06%), heart (3.39%), and kidney (0.56%). Size assessment made on 874 cysts indicated that 308 (35.3%) were small, 251 (28.7%) medium, 89 (10.2%) large, and 226 (25.9%) were calcified. The distribution of characterized cysts in different organs based on their size was found to be statistically significant (P < 0.05). In addition, out of the total 874 cysts collected, 26.9% were fertile, 47.3% sterile, and 25.9% calcified or purulent cysts. There was a significant difference in fertility of cyst from different organs (P < 0.05, χ ² = 27.96), those of lung origin being highly fertile. Likewise, out of the 121 fertile cysts subjected for viability test, 68 (56.2%) were viable. Considering the current result, the total annual economic loss from organ condemnation and carcass weight loss due to bovine hydatidosis at Hawassa Municipal abattoir was estimated at 1,791,625.89 Ethiopian Birr (ETB; 1USD = 12.93ETB). Results in the study were discussed in light of the situation in different parts of Ethiopia and abroad, and finally, relevant recommendations were forwarded.     

Low prevalence of bovine tuberculosis in Somali pastoral livestock, southeast Ethiopia

A cross-sectional study of bovine tuberculosis (BTB) detected by the comparative intradermal tuberculin test (CIDT) was conducted in livestock of the Somali region in southeast Ethiopia??in four pastoral associations from January to August 2009. In 94 herds, each of 15 cattle, camels, and goats was tested per herd leading to a total of 1,418 CIDT tested animals, with 421 cattle, 479 camels, and 518 goats. A herd was considered positive if it had at least one reactor. Prevalence per animal species was calculated using a xtgee model for each species. The individual animal prevalence was 2.0% [95% confidence interval (CI), 0.5?C8.4], 0.4% (95% CI, 0.1?C3%), and 0.2% (95% CI, 0.03?C1.3) in cattle, camels, and goats, respectively. Prevalence of avian mycobacterium purified protein derivative (PPD) reactors in cattle, camels, and goats was 0.7% (95% CI, 0.2?C2.0%), 10.0% (95% CI, 7.0?C14.0%), and 1.9 (95% CI, 0.9?C4.0%), respectively, whereby camels had an odds ratio of 16.5 (95% CI, 5.0?C55.0) when compared to cattle. There was no significant difference between livestock species in BTB positivity. In the present study, the prevalence of bovine tuberculosis was low in Somali pastoral livestock in general and in camels and goats in particular. The high proportion of camel reactors to avian PPD needs further investigation of its impact on camel production.     

A cross-sectional study of epizootic lymphangitis in cart-mules in western Ethiopia

A cross-sectional study was conducted to determine the prevalence of epizootic lymphangitis (EL) in 309 cart-mules (cart-pulling mules) in Bako and Ejaji towns, Western Ethiopia using clinical and microbiological examinations, between November 2002 and April 2003. The overall prevalence was 21% (CI = 16.6–26%). The clinical, histological and mycological characteristics of EL in a cart-mule were similar with those in a horse. There was significant (χ² = 133.5, P = 0.001) association between tick infestation and EL lesions in study cart-mules. Amblyoma coherence and Boophilus genera were the ticks collected from lesions of cases of EL, and thus played a predisposing role. In conclusion, our results showed that EL has high prevalence in cart-mules in the two towns.     

The influence of cattle breed on susceptibility to bovine tuberculosis in Ethiopia

Bovine tuberculosis in domestic livestock such as cattle is an economically important disease with zoonotic potential, particularly in countries with emerging economies. We discuss the findings of recent epidemiological and immunological studies conducted in Ethiopia on host susceptibility differences between native zebu and the exotic Holstein-Friesian cattle that are increasingly part of the Ethiopian National herd, due to the drive to increase milk yields. These findings support the hypothesis that native Zebu cattle are more resistant to bovine tuberculosis. We also summarise the results of experimental infections that support the epidemiological data, and of laboratory experiments that suggest a role for the innate immune response, and in particular interleukin-6, in the outcome of bovine tuberculosis infection.     

Epidemiological study on clinical bovine dermatophilosis in northern Ethiopia

A total of 5586 indigenous and cross breed cattle were examined for clinical dermatophilosis, and 292 (5.22%) were positive. In indigenous cattle, statistically discernible (p < 0.05) difference was recorded between the prevalence in wet (5.5%) and dry (4.0%) seasons. During both seasons, infestation with A. Variegatum significantly (p < 0.05, chi 2 = 59.9) influenced clinical dermatophilosis. A. variegatum-infested cattle were at 7x higher risk (OR, Odds Ratio = 6.8) of acquiring the disease than non-infested ones. Logistic regression analysis of the overall prevalence showed a significant difference (p < 0.05) between prevalence in indigenous and cross breeds; the crossbreeds being at about 3x higher risk (OR = 2.68). Improved management reduced the prevalence in cross breeds from 15.1% in dry to 8.6% in wet season suggesting the significance of management in the epidemiology of dermatophilosis. The disease occurrence was also significantly (p < 0.05, chi 2 = 133.05) affected by agro-climatic (altitude) variation suggesting the impact of rainfall, humidity, vegetation and vector population that varied with altitude. Age and gender had no influence (p > 0.05) on the disease. Our result showed that season of the year, breed, management, infestation with A. variegatum and agro climatic difference are important risk factors influencing the disease pattern in the region. A tick control strategy and a better and adequate management particularly when keeping cross breeds are recommended.     

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.     

A cross-sectional study of bovine tuberculosis in the transhumant and agro-pastoral cattle herds in the border areas of Katakwi and Moroto districts,Uganda

A study to determine the prevalence of bovine tuberculosis in the transhumant and agro-pastoral cattle herds in the border areas of Katakwi and Moroto districts in Uganda was carried out from July 2006 to January 2007 using comparative intradermal tuberculin test containing bovine and avian PPDs. A total of 1470 animals, 612 (41.6%) males and 858 (58.4%) females, 883 (60%) young, 555 (37.8%) adult and 32 (2.2%) old animals were included. The study involved a cross-sectional multistage sampling technique with random selection of individual animals from a herd. The results revealed a 1.3% overall prevalence of bovine tuberculosis in cattle herds in the study area, with a marked variation between sub-counties. The highest recorded prevalence was 6.0% in Kapujan, while no cases were recorded in Ongogonja, Magoro and Katakwi sub-counties. Distinctly different patterns in the avian-bovine reactions were also found in different sub-counties. A multivariate logistic regression showed more positive reactions (OR = 6.3; 95%CI (1.4-26.34) in females than males. BTB prevalence did not differ significantly between cattle maintained in pastoral and agro pastoral production systems. The study demonstrated a relatively low prevalence of bovine tuberculosis in local zebu cattle reared under traditional husbandry systems in Uganda, suggesting low infectiousness of the disease under such mode of production. The risk associated with the consumption of raw milk among the pastoral communities and that, the pooling of milk together from different animals is a common practice, warrants more investigation into the zoonotic transmission of tuberculosis within these communities.     

Prevalence of bovine tuberculosis in pastoral cattle herds in the Oromia region,southern Ethiopia

A cross-sectional study of bovine tuberculosis (BTB) was conducted in pastoral cattle herds in southern Ethiopia, from February to August 2008 using the comparative intradermal tuberculin test. The prevalence of BTB and the risk factors for having positive reactor herds were assessed in four pastoral associations in two districts of southern Ethiopia, namely Goro-Dola with 242 cattle in 16 herds and Liben with 231 cattle in 15 herds. A herd was considered positive if there was at least one reactor animal in a herd. The test results were interpreted based on the Office Internationale des Epizooties recommended 4-mm and a recently suggested 2-mm cut-off. The apparent individual animal prevalence of tuberculin reactors was 5.5% (95% confidence interval (CI), 4.0–8.0%) and 7.0% (95% CI, 5.0–10.0%), whereas the true prevalence estimate was 4.4% (95% CI, 0.8–8.0%) and 6.1% (95% CI, 2.6–9.5%), when using the 4-mm and the 2-mm cut-offs, respectively. The overall herd apparent prevalence of tuberculin reactor animals was 41.9% (95% CI, 24.9–60.9%) and 48.4% (95% CI, 30.2–66.9%) with the 4-mm and 2-mm cut-offs, respectively. A positive tuberculin test was associated with the age of animals and the main drinking water sources during dry seasons. In order to investigate the public health risks and the epidemiological importance of BTB in the area, we recommend to include other livestock species (camels and goats) as well as humans in future studies.     

Effect of skin testing and segregation on the prevalence of bovine tuberculosis, and molecular typing of Mycobacterium bovis, in Ethiopia

In 2002, the prevalence of bovine tuberculosis (tb) among 500 cattle on Holeta Farm, near Addis Ababa, Ethiopia, was 48 per cent, and the farm was divided into positive and negative herds. After three consecutive rounds of skin testing and segregation of skin test-positive and -negative animals, the prevalence of bovine tb was reduced from 14 per cent to 1 per cent in the negative herd in a year. Spoligotyping of 41 isolates from 17 cows gave an identical and unique spoligotype pattern, which can be represented as the binary number 1100000101111110111111100010000000000100000, where 1 indicates the presence of a spacer and 0 represents a loss. This spoligotype pattern had not previously been reported on the Mycobacterium bovis spoligotype database, and it was therefore designated SB1176, Ethiopian M bovis strain 1 (EMbs1). The variable number tandem repeat (VNTR) profile of the strain was 5254(*)33.1, which differed from the VNTR profile of strains reported in Great Britain.     

Risk factors of bovine tuberculosis in cattle in rural livestock production systems of Ethiopia

This study shows a representative stratified cluster sample survey of the prevalence of comparative intradermal tuberculin test in cattle from four regions in Ethiopia. Using a cut-off for positivity of 2 mm, it assesses possible risk factors for tuberculin-positive reaction in cattle. Seventy-three villages in 24 kebeles (administrative units) were randomly selected, from which 2216 cattle from 780 owners were tested. In addition, 450 of these cattle owners were interviewed for risk factor assessment. Ninety-nine percent of the tested cattle in this rural livestock production system were traditional zebus. The individual overall prevalence of cattle bovine tuberculosis (BTB)e was 3%, with the highest found in Meskan Mareko, in Central Ethiopia (7.9%) and the lowest in Woldia, in the North East edge of the Rift Valley (1.2%). Generalised Linear Mixed Models (GLMM) with random effect on kebeles was used to analyse risk factors of cattle reactors and human tuberculosis (TB) infection. Purchase of cattle and presence of other livestock in the herd were statistically significant, with OR: 1.7, p-values of 0.03 and OR: 2, p = 0.05, respectively. Family members diagnosed with TB or showing clinical signs of extra-pulmonary TB (EPTB) were reported in 86 households (19%). None of the assessed potential risk factors of disease transmission between cattle and human (food consumption, livestock husbandry and presence of BTB-positive cattle) were statistically significant.     

Cattle brucellosis in traditional livestock husbandry practice in Southern and Eastern Ethiopia,and its zoonotic implication

Background

Cattle brucellosis has significant economic and zoonotic implication for the rural communities in Ethiopia in consequence of their traditional life styles, feeding habits and disease patterns. Hence, knowledge of brucellosis occurrence in traditional livestock husbandry practice has considerable importance in reducing the economic and public health impacts of the disease.

Methods

A total of 1623 cattle sera were serially tested using the rose Bengal test as screening and complement fixation test as confirmatory tests. The Stata survey command was used to establish prevalences for the overall and individual variables, while potential risk factors for seropositivity were analyzed using a multivariable logistic regression analysis.

Results

The results showed that 3.5% (95% CI = 2.4, 4.5%) of the animals and 26.1% (95% CI = 18.6, 33.7) of the herds tested had antibodies against Brucella species. Village level seroprevalence ranged from 0% to 100%. A higher seroprevalence was observed in pastoral system than mixed farming although this variable was not significant in the final model. The final logistic regression model identified herd size; with large (odd ratio (OR) = 8.0, 95% CI = 1.9, 33.6) and medium herds (OR = 8.1, 95% CI = 1.9, 34.2) showing higher risk of Brucella infection when compared to small herds. Similarly, the odds of Brucella infection was higher in cattle aged above 4 years when compared to age groups of 1-2 (OR = 5.4, 2.1, 12.9) and 3-4 years (OR = 3.1, 95% CI = 1.0, 9.6). Herd level analysis of the risk factors revealed that large and medium herds as well as herds kept with multiple livestock species were at higher risk of acquiring Brucella infection. Brucellosis in traditional livestock husbandry practices certainly poses a zoonotic risk to the public, in consequence of raw milk consumption, close contact with animals and provision of assistance during parturition. Due to lack of diagnostic facilities and information on its occurrence, human brucellosis is most likely misdiagnosed for other febrile diseases prevailing in the areas and treated empirically.

Conclusions

The results of this study demonstrated that bovine brucellosis is widely prevalent in the study areas particularly in pastoral production system. Hence, the study suggests the need for implementing control measures and raising public awareness on prevention methods of brucellosis.     

A comparative longitudinal study of bovine trypanosomiasis in tsetse-free and tsetse-infested zones of the Amhara Region, northwest Ethiopia

A study was conducted to determine the incidence of trypanosome infections in cattle in tsetse-free and tsetse-infested zones of the Amhara Region of northwest Ethiopia. A total of six sentinel herds were established and the cattle observed during a period of 8 consecutive months. The prevalence of seropositive cattle was high in both the tsetse-free and tsetse-infested zones. The average monthly incidence of trypanosome infection, determined using molecular diagnostic tools, was 20.9% and 25.7% in the tsetse-free and the tsetse-infested zones, respectively. In the tsetse-free, Trypanosoma vivax was responsible for 90.9% of the cattle trypanosome infections. In the tsetse-infested zone, Trypanosoma congolense and T. vivax contributed almost equally to the trypanosome infections in cattle. Trypanosome infection, regardless of species, resulted in anaemia as evidenced by a significant decrease in the packed cell volume of the infected animal. The outcome of this longitudinal study suggests that control of trypanosomiasis in the Amhara Region cannot be achieved by tsetse control alone. Supplemental measures to include drug therapy and biting fly control are discussed.     

A study on sheep farming practices in relation to future production strategies in Bensa district of Southern Ethiopia

Tropical Animal Health and Production - The study was carried out in Bensa district of Sidama zone, Southern Ethiopia. Agro-ecologically, the study sites were classified into highland and...     

Sero-prevalence of bovine brucellosis and its risk factors in Jimma zone of Oromia Region,South-western Ethiopia

A cross sectional sero-prevalence study was conducted on 1,595 cattle in Jimma zone, Ethiopia to investigate the status of bovine brucellosis and identify potential risk factors. Sera samples were analyzed using Rose Bengal Plate Test (RBPT) and Complement Fixation Test (CFT). The overall individual and herd level sero-prevalences were 3.1% (n = 1,595) and 15.0% (n = 227), respectively. The sero-prevalence of bovine brucellosis at individual animal level was significantly higher in non-pregnant (11.18%) than pregnant (2.77%) and lactating (22.35%) than non-lactating animals (2.46%). Moreover, significantly higher sero-prevalence was observed in herds of larger sizes. Individual animal sero-prevalence was also positively associated with the occurrence of abortion (26.98 and 1.54% in those with and without previous history of abortion, respectively). Generally, the sero-prevalence of bovine brucellosis found in Jimma area was not high and the sero-prevalence was closely associated with some of the risk factors considered at individual animal and herd level.