Spatiotemporal analysis and forecasting of lumpy skin disease outbreaks in Ethiopia based on retrospective outbreak reports

Introduction

Lumpy skin disease is a viral disease that affects cattle belonging to genus Capripoxvirus (Poxviridae) and lead to significant economic losses.

Objective

The objective of this study was to evaluate the distribution of lumpy skin disease (LSD) outbreaks and predict future patterns based on retrospective outbreak reports in Ethiopia.

Methods

Data were collected through direct communication with regional laboratories and a hierarchical reporting system from the Peasant Associations to Ministry of Agriculture. Time-series data for the LSD outbreaks were analyzed using classical additive time-series decomposition and STL decomposition. Four models (ARIMA, SARIMA, ETS, STLF) were also used to forecast the number of LSD outbreaks that occurred each month for the years (2021-2025) after the models' accuracy test was performed. Additionally, the space-time permutation model (STP) were also used to study retrospective space-time cluster analysis of LSD outbreaks in Ethiopia.

Results

This study examined the geographical and temporal distribution of LSD outbreaks in Ethiopia from 2008 to 2020, reporting a total of 3,256 LSD outbreaks, 14,754 LSD-positive cases, 7,758 deaths, and 289 slaughters. It also covered approximately 68% of Ethiopia's districts, with Oromia reporting the highest LSD outbreaks. In the LSD's temporal distribution, the highest peak was reported following the rainy season in September to December and its lowest peak in the dry months of April and May. Out of the four models tested for forecasting, the SARIMA (3, 0, 0) (2, 1, 0) [12] model performed well for the validation data, while the STLF+Random Walk had a robust prediction for the training data. Thus, the SARIMA and STLF+Random Walk models produced a more accurate forecast of LSD outbreaks between 2020 and 2025. From retrospective Space-Time Cluster Analysis of LSD, eight possible clusters were also identified, with five of them located in central part of Ethiopia.

Conclusion

The study's time series and ST-cluster analysis of LSD outbreak data provide valuable insights into the spatial and temporal dynamics of the disease in Ethiopia. These insights can aid in the development of effective strategies to control and prevent the spread of the disease and holds great potential for improving efforts to combat LSD in the country.

Livestock producers' knowledge, attitude, and behavior (KAB) regarding antimicrobial use in Ethiopia

Introduction

Inappropriate antimicrobial use (AMU) in livestock production is an important aspect of the global burden of antimicrobial resistance (AMR). In Ethiopia, a low-income country with a large and increasing livestock population, AMU in food animals is not properly regulated. Hence, farmers are fully free to use antimicrobials to their (perceived) benefit. Therefore, understanding farmers' mindsets is important to improve antimicrobial stewardship in the livestock sector.

Methods

This cross-sectional study was conducted to assess livestock disease management practices and knowledge, attitude, and behavior (KAB) among livestock producers regarding AMU, residues, and resistance, as well as factors potentially explaining differences in KAB. We determined the KAB of livestock owners of three selected districts of central and western Ethiopia (n = 457), using a pretested questionnaire administered through face-to-face interviews. Logistic regression was used to evaluate the association between potential explanatory variables and the KAB scores of the respondents.

Results

The results showed that 44% of the farmers used antimicrobials in the past few years, where antibiotics (21%) and trypanocides (11%) were most widely used to manage livestock diseases. Furthermore, most farmers showed poor knowledge about AMU, residues, and AMR (94%) and unfavorable attitudes (<50% correct answers) toward contributing factors for AMR (97%). On the contrary, 80% of the respondents had overall good behavior scores (≥50% correct answers) related to AMU. Multivariate analysis results showed that having good knowledge, keeping ≥2 animal species, and the occurrence of ≥4 livestock diseases on the farm in a year were strong predictors of bad behavior scores (p < 0.05). The findings of the current investigation also revealed that the incidence of livestock diseases on the farm and a higher level of formal education significantly contributed to better knowledge and desirable attitudes but bad AMU behavior.

Conclusion

A low level of awareness about and undesirable attitudes toward AMU and AMR could potentially affect farmers' behavior toward judicious AMU, thus requiring awareness creation efforts on livestock disease management practices.

Magnitude and Antimicrobial Susceptibility Profile of Salmonella Recovered from Export Abattoirs Located in East Shewa, Ethiopia

Background

Objective

Methods

Results

Conclusion

Comparative Immunogenicity Evaluation of Two Infectious Bursal Disease Vaccines Commonly Used in Broiler Chickens in Ethiopia

Purpose

Infectious bursal disease (IBD) is one of the most endemic diseases of commercial poultry in Ethiopia. Vaccination is used as the major means of IBD prevention and control. A study was conducted to compare the immunogenicity of two commercially available IBD vaccines in broiler chicken with maternally derived antibody (MDA).

Methods

A total of 270 day-one-old chicks were randomly assigned to three groups, group 1 vaccinated with product A vaccine at the age of 7 and 19 days and group 2 with product B vaccine on day 15 and 22 while group 3 were kept as control. Six chickens were also randomly selected and bled on day 1 for differential leukocyte count (DLC) and determination of MDA. Representative chickens from each group were bled at 24th and 42nd days of age for antibody titration using the indirect ELISA test. DLC scores were determined in the 1st and 24th days.

Results

The result revealed highly significant differences (P = 0.001) between group 1 and group 2 in DLC at 24th days of age. Antibody titers against IBD were differed significantly (P = 0.02) at 24th and 42nd days of age in broilers vaccinated with product A and product B vaccines.

Conclusion

Both vaccines have induced an adequate immunological response at the end of the experiment; however, product A has shown significantly higher antibody titers against the IBDV and DLC than product B.

Antitrypanosomal activity of hydromethanol extract of leaves of Cymbopogon citratus and seeds of Lepidium sativum: in-vivo mice model

Background

Trypanosomiasis is one of the neglected tropical diseases of both humans and animals which decreases their productivity and causes death in the worst scenario. Unavailability of vaccines, the low therapeutic index of trypanocidal drugs, and the development of resistance lead to the need for research focused on developing alternative treatment options especially from medicinal plants. The present study was aimed to investigate antitrypanosomal activities of leaves of Cymbopogon citratus and seeds of Lepidium sativum in in-vivo mice model.

Methods

The plant extracts were prepared by maceration using 80% methanol and reconstituted with 10% dimethyl sulfoxide (DMSO) to have the desired concentration. The test doses were adjusted to 100, 200 and 400 mg/kg based on the toxicity profile. The plants extracts were administered to the respective groups of mice after the 12^th day of field isolate T. congolense inoculation for seven consecutive days. The level of parasitemia, bodyweight, packed cell volume (PCV), and differential white blood cell counts were measured.

Results

The in -vivo test results revealed that both plant extracts had dose-dependent antitrypanosomal activity. Both crude extracts showed a significant reduction in parasite load (P < 0.05), increased or prevent the fall of PCV value (P < 0.05), decreased lymphocytosis and increased neutrophil counts (p < 0.05) and improved bodyweight but significant bodyweight increment (P < 0.05) was observed only in C. citratus treated mice compared to the negative and positive controls.

Conclusion

The present study concluded that the crude extracts of leaves of C. citratus and seeds of L. sativum had antitrypanosomal effects. Both plants extracts reduced parasitemia level, prevented anemia and improved bodyweight of treated mice. Comparative results from all tested parameters showed that the best activities were observed with C. citratus treated groups of mice.

Global distribution, host range and prevalence of Trypanosoma vivax: a systematic review and meta-analysis

BACKGROUND

Trypanosomosis caused by Trypanosoma vivax is one of the diseases threatening the health and productivity of livestock in Africa and Latin America. Trypanosoma vivax is mainly transmitted by tsetse flies; however, the parasite has also acquired the ability to be transmitted mechanically by hematophagous dipterans. Understanding its distribution, host range and prevalence is a key step in local and global efforts to control the disease.

METHODS

The study was conducted according to the methodological recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. A systematic literature search was conducted on three search engines, namely PubMed, Scopus and CAB Direct, to identify all publications reporting natural infection of T. vivax across the world. All the three search engines were screened using the search term Trypanosoma vivax without time and language restrictions. Publications on T. vivax that met our inclusion criteria were considered for systematic review and meta-analysis.

RESULT

The study provides a global database of T. vivax, consisting of 899 records from 245 peer-reviewed articles in 41 countries. A total of 232, 6277 tests were performed on 97 different mammalian hosts, including a wide range of wild animals. Natural infections of T. vivax were recorded in 39 different African and Latin American countries and 47 mammalian host species. All the 245 articles were included into the qualitative analysis, while information from 186 cross-sectional studies was used in the quantitative analysis mainly to estimate the pooled prevalence. Pooled prevalence estimates of T. vivax in domestic buffalo, cattle, dog, dromedary camel, equine, pig, small ruminant and wild animals were 30.6%, 6.4%, 2.6%, 8.4%, 3.7%, 5.5%, 3.8% and 12.9%, respectively. Stratified according to the diagnostic method, the highest pooled prevalences were found with serological techniques in domesticated buffalo (57.6%) followed by equine (50.0%) and wild animals (49.3%).

CONCLUSION

The study provides a comprehensive dataset on the geographical distribution and host range of T. vivax and demonstrates the potential of this parasite to invade other countries out of Africa and Latin America.

Prevalence and antibiotic susceptibility pattern of Escherichia coli O157:H7 isolated from harvested fish at Lake Hayq and Tekeze dam, Northern Ethiopia

Fisheries play a significant role in food security, livelihood, and source of income in developing countries. Although fish are a healthy source of protein, they can also spread diseases caused by pathogenic micro-organisms they may harbor. Epidemiology of foodborne pathogens is not well studied in Ethiopia. To address this issue to some extent, a cross-sectional study with a simple random sampling approach was conducted from October 2017 to May 2018 with the objectives of to isolate and estimate the prevalence of Escherichia coli O157: H7 in fish, and to evaluate the antimicrobial susceptibility pattern of the isolates in selected Lakes of Northern Ethiopia. All the microbial identification and isolation procedures were conducted based on ISO 6887-3:2017 recommendations. Antimicrobial susceptibility test was also performed following the standard procedure of Kirby-Bauer disk diffusion protocol. From the total 410 fish samples examined, six (1.46%) of them were found contaminated with Shiga toxin-producing Escherichia coli O157: H7 strain. The organism was isolated from landing sites (5/293) and local retail markets (1/75). Besides, Escherichia coli O157: H7 was isolated from filleted fish (5/214) and whole fish (1/125); however, it was not isolated from samples of ready to eat fish and working environments of restaurants. The antibiotic susceptibility test revealed that the isolates were resistant to Ampicillin and Streptomycin disks. However, Ciprofloxacin, Gentamicin and Nalidixic acid were found effective in inhibiting the growth of all of the isolates. Since pathogenic Escherichia coli strain was detected from fish, raw and undercooked fish consumption in Ethiopia may result in contracting infections. The occurrence of such pathogenic organisms in fish indicates the need for intervention by stakeholders. Supports like freezers, generators, the establishment of fish processing plants and on job training about proper fish handling practices may play a tremendous role in decreasing the level of contamination of fish in Ethiopia.

One Health collaborations for zoonotic disease control in Ethiopia

Zoonotic diseases require a One Health approach for successful control and elimination due to the nature of their transmission between animals and humans. One Health recognises that the health of humans, animals, and the environment are all interconnected. Ethiopia has committed itself to controlling five prioritised zoonotic diseases (rabies, anthrax, brucellosis, leptospirosis and echinococcosis), using a One Health approach. The National One Health Steering Committee (NOHSC) provides a framework for national stakeholders to address gaps in multisectoral communication, coordination and collaboration. In addition, the NOHSC oversees the formation of several specialised disease-focused groups, referred to as 'Technical Working Groups' (TWGs). These TWGs are responsible for developing disease prevention and control strategies, as well as implementing disease-focused public health activities and providing recommendations to the NOHSC. Ethiopia's success using the One Health approach and its efficient control of zoonotic diseases will depend on the commitment of all member Ministries to support the NOHSC and TWGs, as well as to build capacity in Ethiopia's workforce and laboratories, a task supported by its many international partners.

Seroprevalence of Neospora caninum and associated risk factors in intensive or semi-intensively managed dairy and breeding cattle of Ethiopia

A cross-sectional study of Neospora caninum infection was conducted in major milksheds of Ethiopia. Cattle (n=2334) from 273 farms were bled and the sera screened for antibodies against N. caninum using a commercial ELISA kit. Herd and individual animal level data were collected from farm records and a semi-structured questionnaire format. The overall animal level seroprevalence was 13.3%, while the prevalence at farm level was 39.6%. In urban and peri-urban smallholder dairy farms, the seroprevalence was 14.9%, while 12.9% and 9.8% reactors were found among commercial dairy farms and breeding cattle, respectively. At farm level, 35.7% of urban and peri-urban farms, 47.5% of the commercial farms and five of the breeding farms were found to have at least one infected animal. Purchased cows (OR: 2.3) and cows with history of maternal reproductive disorders (OR: 2.1) were associated with seropositivity at the individual animal level. Crossbred cattle (Holstein-Friesian crossed with indigenous zebu) were associated with lower risk than pure breeds (OR: 0.6). A trend of prevalence increment was observed for large herd sizes (OR: 1.8). Other factors that were associated with seropositivity were: presence of farm dogs for more than 5 years (OR: 1.9), access to farm by wild carnivores (OR: 3.1) and compromised farm hygienic status (OR: 3.4). Abortion, retention of foetal membrane and metritis were the most frequently reported clinical reproductive disorders among seropositive cattle. Together, these finding indicate that N. caninum infection is highly prevalent, widely distributed and clinically important in dairy and breeding cattle of Ethiopia. N. caninum should be considered an important infectious cause of reproductive disorders in Ethiopian cattle, and the risk factors for exposure identified here should be used as basis for implementing control measures that could limit the transmission of this infection.

Ovarian activity, transuterine embryo migration and prenatal losses in Ethiopian highland ewes

A study was conducted on 1442 Ethiopian highland ewes to determine the seasonality of ovarian activity, intrauterine embryo migration and prenatal reproductive wastage. Assessment of ovarian follicular activity revealed that a higher (p < 0.01) proportion of ewes ovulated in the dry season than in the heavy and light rainy seasons. However, there was a tendency (p = 0.057) of decline in the mean number of ovulations per ewes during the light rains. The mean diameter of the largest follicle on the ipsilateral ovary was higher (p < 0.01) in both ewes with single and those with twin corpora lutea (CL) than on the contralateral ovary; and, compared to ewes with single CL, it was higher (p < 0.05) in those with twin CL. The right ovary was more active (p < 0.001) only in single-ovulating ewes. Similarly, a higher (p < 0.001) proportion of ewes were pregnant in the right horn. Embryos migrated to the opposite horn in single-, twin- and triple-ovulating ewes. There was a higher (p < 0.001) tendency for the left-to-right migration than the opposite. There was significant (p < 0.01) association between embryo loss and site and number of ovulations. Embryo loss was higher (p < 0.01) in ewes with twin ovulations on the right ovary. It is very likely that these results indicate a better chance of embryo survival in the right uterine horn.

Reduced Milk Production in Udder Quarters with Subclinical Mastitis and Associated Economic Losses in Crossbred Dairy Cows in Ethiopia

The objective of the study was to estimate the losses associated with subclinical mastitis (SCM) in crossbred dairy cows in the Central Highlands of Ethiopia. A split udder investigation was performed with 30 cows to determine production losses associated with SCM. Each quarter of the study cows was examined using the California Mastitis Test (CMT) and quarter milk production was measured over a period of 8 days. Production losses were determined for different CMT scores by comparing production of quarters with CMT score 0 to quarters with CMT scores trace, 1, 2 and 3, respectively. Using data from a recently published study, economic losses were determined for different farm sizes and production subsystems by multiplying the prevalence of the respective CMT scores with the production losses associated with these CMT scores. Mean quarter milk production was 0.82 +/- 0.40 kg per milking in the split udder trial. Milk production was reduced by 1.2%, 6.3%, and 33% in quarters with CMT scores 1+, 2+, and 3+, respectively. Using data from the published study, a quarter with SCM lost an average of 17.2% of its milk production. Production losses associated with SCM were estimated at 5.6% for the Addis Ababa Milk Shed. Stratified losses were highest (9.3%) in urban dairy farms (UDF) and small-scale farms (6.3%). The estimates of the financial losses ranged from US dollars 29.1 in dairy herds in secondary towns (DHIST) to US dollars 66.6 in UDF. A total loss of US dollars 38 was estimated for each cow per lactation. Reducing mastitis in UDF (highest prevalence) to the level of DHIST (lowest prevalence) could reduce the loss by US dollars 35. As this does not include costs associated with treatment or culling of diseased cows, this figure probably underestimates the possible benefits of control measures.

Risk factors for dairy cow mastitis in the central highlands of Ethiopia

This study, with the objective of assessing the effect of risk factors on dairy cow mastitis in the central highlands of Ethiopia, was undertaken between February and September 2001 in the urban and peri-urban areas of Addis Ababa, Ethiopia. A prevalence study and questionnaire survey were carried out simultaneously. Clinical examination of lactating udders and California mastitis test (CMT) determined clinical and subclinical mastitis, respectively. Risk factors for subclinical and clinical mastitis were identified from data on animals and farm management by chi-square analysis and subsequent logistic regression. Cows aged at least 8 years, with poor body condition, with at least 8 parities and in at least the eighth month of lactation had a significantly higher risk for subclinical mastitis (p < 0.05). The risk was reduced for cows up to their third parity in good body condition and for cows receiving dry cow therapy. Cows aged at least 4 years, or with at least 8 parities, cows in at least the fourth month of lactation, cows with poor body condition, leaking milk or previous udder infections had a significantly higher risk of clinical mastitis (p <0.05). The risk was reduced by the use of separate towels for udder cleaning and by drying off at the end of lactation. Most of the risk factors were in agreement with previous reports. However, stage of lactation and drying-off style were in contrast to others. Further research is needed to identify the interrelationship between production level, specific pathogens and management risk factors.

Abnormalities of the testes and epididymis in bucks and rams slaughtered at Debre Zeit abattoir, Ethiopia

A study was conducted at Debre Zeit export abattoir on 404 bucks belonging to four breeds and 167 rams of two breeds. The animals were selected from the slaughter flock using stratified sampling based on breed. Ante-mortem and post-mortem examinations were carried out after each animal was carefully identified. Various genital abnormalities were observed, among which testicular atrophy and epididymitis were the predominant genital problems in both bucks and rams. The prevalence of cryptorchidism was higher (p<0.05) in bucks than in rams, while epididymitis (p<0.05), sperm granuloma (p<0.01) and epididymal cysts (p<0.05) were more frequent in rams. In bucks, none of these abnormalities was significantly associated with age (p>0.05). However, testicular atrophy (p<0.01), epididymitis (p<0.01) and haemorrhagic lesions (p<0.05) were associated with breed, the prevalence being higher in Woito-Guji and Boran bucks than in the Arsi-Bale and Afar breeds. In rams, age affected (p<0.05) the incidence of testicular atrophy, epididymitis and sperm granulomas. Epididymitis, sperm granuloma and epididymal cysts were more frequent (p<0.01) in Adal rams than in Black Head Somalis.

Changes in the weight, collagen concentration and content of the uterus and cervix of the ewe during pregnancy

The dry and wet weights of the uterus (caruncular and intercaruncular areas) and cervix were measured in non-pregnant (n = 5) and pregnant (n = 25) ewes post mortem; for the latter, five were obtained for each of the 5 months of gestation. The total collagen tissue content was measured in both areas of the uterus and cervix by hydroxyproline analysis and image analysis of Haematoxylin-Van Gieson stained tissue sections. Both wet and dry uterine weights increased significantly with gestational age (P < 0.001). The water content of uterine and cervical tissue remained constant, at between 83 per cent to 85 per cent and 76 per cent to 80 per cent, respectively. There was a close correlation between the two methods used to determine the collagen content (r = 0.96, P < 0.001), and between the increasing weight of the uterus during pregnancy and the total collagen content of tissues (r = 0.97, P < 0.001). At all stages, the total collagen content of the cervix [mean (SEM) 96.2 (5.4) mg g(-1)] was significantly greater (P < 0.001) than that of the caruncular mean [mean (SEM) 24.3 (1.4) mg g(-1)], and the intercaruncular areas [mean (SEM) 29.0 (1.0) mg g(-1)]. The changes in uterine and cervical weights and collagen content of the tissues were similar to those reported in other related species.

Acute phase protein response of ewes and the release of PGFM in relation to uterine involution and the presence of intrauterine bacteria

The rate of uterine involution postpartum was monitored in 13 suckling mule ewes by using radio-opaque markers and radiography, and each ewe was also monitored for intrauterine bacterial contamination during the first week, using a sterile guarded swab. Peripheral plasma or serum concentrations of haptoglobin, seromucoid, ceruloplasmin and 15-keto-13,14-dihydro-prostaglandin F2 alpha (PGFM) were measured up to six weeks postpartum. The maximum reduction in the length of the uterine body and in the diameters of the horns occurred by 28 days postpartum, except in one ewe in which the size of the uterus continued to decrease for 42 days. Four ewes were positive for intrauterine bacterial contamination; Escherichia coli, clostridial species, Staphylococcus aureus, Streptococcus uberis and Enterococcus species were isolated in pure or mixed culture. The presence of intrauterine bacteria did not affect the time for the completion of uterine involution. No bacteria were isolated from the ewe in which involution was delayed, but it had a different acute phase protein response and was therefore excluded from further analyses. In the remaining 12 ewes the mean postpartum haptoglobin response increased, with peak concentrations occurring on day 1, and decreased slowly as uterine involution progressed, but the four contaminated ewes had a significantly greater response. There was no difference between the prepartum and postpartum concentrations of seromucoid in the eight sterile ewes, but significant increases were observed in the contaminated group; the concentrations of ceruloplasmin did not vary in either group. The concentrations of PGFM were higher during the early postpartum period in the ewes with contaminated uteri.