Helminth Parasite Prevalence in the Endangered Ethiopian Wolf (Canis simensis) in Web Valley, Bale Mountains National Park, Ethiopia.

Ethiopian wolves (EWs), Canis simensis, are the rarest canids in the world and Africa's most endangered carnivore, found in only six isolated habitat fragments in the highlands of Ethiopia. Previous reports on the prevalence of parasites in the EW in Bale Mountains National Park (BMNP) are limited, with little information on their helminth fauna. This study seeks to understand the prevalence of helminth parasites in the EW in BMNP, Ethiopia. In this study, fecal samples were collected from 43 EWs in Web Valley (WV), BMNP, from June to October 2020, and the presence of helminth eggs was assessed using fecal sedimentation and centrifugal floatation methods with microscopy. Forty-two out of 43 fecal samples from wolves (98%) contained eggs from two taxonomic groups of helminths. Eggs from Capillaria spp. and Trichuris vulpis were found most frequently, followed by Toxocara canis, Diphyllobothrium spp., Toxascaris leonina, and Capillaria aerophila. One EW (2%) was recorded for harboring the cestode Moniezia expansa. About 9 of the 43 EWs (21%) presented monospecific infection: 9 EWs (21%) harbored 2 parasite species, 9 EWs (21%) hosted 3 parasite species, 11 EWs (26%) had infection involving 4 parasite species, 2 EWs (5%) were infected with 5 parasite species, 1 EW (2%) presented 6 parasite species, 1 EW (2%) harbored 7 parasite species, and 1 EW (2%) was diagnosed without parasite species. Concurrent helminth infection was highly associated with female EW. Megeti 3 was associated with a low level of concurrent helminth infection. The prevalence of helminth parasites found in wolves in the study area suggests that the environment is highly contaminated with intestinal parasites. Regular control of parasite transmission in EW, domestic dogs, and humans in and around BMNP, public education, and further parasite epidemiological studies must be conducted.

Knowledge, Attitudes, Practices, and Risk Perception of Antimicrobial Use and Antimicrobial Resistance Among Dairy Farm Owners/Workers in Addis Ababa, Ethiopia.

Introduction: Antimicrobial resistance (AMR) is one of the most significant global health threats to the public, animals, and the ecosystem. Inappropriate use of antibiotics in food animals is considered a major driver of AMR in humans. This study was conducted to assess the knowledge, attitude, practices, and risk perception (KAPP) of dairy farm owners/workers in Addis Ababa about antibiotic use and resistance. Methods: A face-to-face interview using a structured questionnaire was conducted with 281 respondents in four selected subcities of Addis Ababa. The responses provided by each participant were recoded into a binary scale based on the mean score of each domain. Pearson chi-square was used to check the association between the KAPP and sociodemographic characteristics of the respondents and logistic regression analysis was done to explore the factors associated with KAPP. Results: Overall, more than half of the surveyed dairy farm owners/workers had good knowledge (57.7%) and appropriate practice (53.0%), while less than half of the respondents showed desirable attitudes (47.7%) and positive risk perceptions (42.7%). The findings revealed a strong association between the respondents' KAPP and education and between knowledge and risk perception and farming experience. Conclusion: This study found that continuous education of dairy farm owners/workers regarding antimicrobial usage and antimicrobial resistance in dairy farms will increase their awareness and perception of risk as well as motivate them to adopt desirable attitudes and appropriate practices, and consequently limit inappropriate use of antimicrobials leading to mitigating emergence of AMR.

Epidemiological study on bovine cystic echinococcosis: Abattoir survey, cyst characterization and its economic impact at Mekaneyesuse municipality abattoir, Northwest Ethiopia.

Cystic echinococcosis (CE) is a major medical and veterinary concern in the world. It is one of the significant diseases in livestock farming communities managed under extensive grazing system like Ethiopia. Domestic intermediate hosts are an important reservoir for the disease spread. A cross-sectional study was conducted to determine the occurrence and economic losses associated with CE in cattle slaughtered at Mekaneyesuse Municipality abattoir, South Gondor zone of Amhara Region, North West Ethiopia. Ante-mortem inspection, postmortem examinations of organs, hydatid cyst characterization and financial loss estimations were conducted. The study was conducted on 384 cattle. The involvement of different organs was as follows: lungs (46.09%), liver (45.22%), heart (6.09%), and kidneys (2.6%). Out of the total of 115 cysts observed, small cysts constituted 57.39%, medium-sized were 34.78%, and large cysts accounted for 7.83%. Of these 115 cysts, 53.9% were fertile which included both viable (29%) and non-viable (71%) cysts. Furthermore, 46.1% cysts were non fertile, 62.3% were sterile and 37.7% were calcified. Based on the origin of animal, the prevalence of hydatid cysts was recorded to be 31.25%, 24%, 22.05% and 14.25% in Tachgayent, Semada, Andabet and Estie district, respectively. Higher cyst occurrence was observed in animals with poor body condition (51.56%) followed by medium (13.7%) and good body condition scores (8.25%). The total annual economic loss due to the direct condemnation of organs and indirect losses were estimated to be 851,252.68 ETB ($16,061.06). This study revealed that CE is economically important disease at Mekaneyesuse, South Gondar Zone, Amhara Region, Northwest Ethiopia. A more comprehensive investigation is required on prevalence and genotyping of Echinococcus granulosus s.l. cysts is important also to identify and estimate the relative contribution of each species or genotype to the disease in this area. Moreover, efforts to enhance public awareness in the area should also be pursued.

Epidemiology of Echinococcus granulosus sensu lato in the Greater Horn of Africa: A systematic review.

BACKGROUND: Cystic echinococcosis (CE) is a neglected zoonotic disease that is caused by Echinococcus granulosus sensu lato (s.l.), the life cycle of which involves multiple hosts. We conducted a systematic review (SR) on E. granulosus s.l. in the Greater Horn of Africa (GHA), to provide a picture of its recent epidemiology across all hosts. METHODS: For this SR, conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, five electronic databases, as well experts in the region were consulted to retrieve records published between 2000 and 2022, reporting the presence of E. granulosus s.l. infections in any natural host in the GHA (Djibouti, Eritrea, Ethiopia, Kenya, Sudan, Somalia, South Sudan, Tanzania and Uganda). PRINCIPAL FINDINGS: A total of 247 records were retained, describing the presence of E. granulosus s.l. throughout the GHA, except for Djibouti. Only few population surveys on human CE were conducted in the area, with the prevalence ranging between 0.3 and 11.3%. In animals, the reported prevalence ranged up to 61.6% in camels, 88.4% in cattle; 65.2% in goats, 9.9% in pigs, 67.8% in sheep and 94.5% in dogs. In addition, E. granulosus s.l. was also reported in wildlife. A total of five species were reported in the different hosts, namely E. granulosus sensu stricto (G1, G3, GOmo), E. canadensis (G6/7), E. ortleppi (G5), E. felidis, and E. equinus (G4). CONCLUSIONS: We confirm that E. granulosus s.l. is prevalent throughout the GHA. Nevertheless, despite our efforts to screen grey literature, an accurate assessment of the epidemiology in GHA remains challenging, due to the lack of combined host, in-depth risk factor and behavioural studies, as well as the wide diversity in subpopulations studied and diagnostic tools used. Interdisciplinary and transboundary partnerships would be essential for the design of effective control strategies, tuned to the GHA setting.

Seroprevalence and risk factors for Toxoplasma gondii infection among pregnant women at Debre Markos Referral Hospital, northwest Ethiopia.

BACKGROUND: To assess the seroprevalence and risk factors of Toxoplasma gondii infection in pregnant women at the Debre Markos Referral Hospital, northwest Ethiopia. METHODS: A facility-based cross-sectional study was undertaken among pregnant women from March 2020 to May 2021. Sociodemographic and clinical data were collected from randomly selected participants. Five millilitres of blood was collected and an enzyme-linked immunosorbent assay kit was used to test for T. gondii immunoglobulin G (IgG) antibodies. A logistic regression model was computed to identify the risk factors. The adjusted odds ratio (aOR) was estimated along with the 95% confidence interval (CI). A statistically significant association was defined as p<0.05. RESULTS: T. gondii IgG antibody positivity was found in 38.8% (n=132) of 340 pregnant women. Contact with cats (AOR 2.5 [95% CI 1.5 to 4.2]), eating raw/undercooked meat (AOR 5.7 [95% CI 3.2 to 10.3]), consuming unwashed vegetables (AOR 4.1 [95% CI 2.1 to 8.0]), a history of abortion (AOR 1.9 [95% CI 1.1 to 3.3]) and drinking water sources (AOR 2.5 [95% CI 1.2 to 5.2]) demonstrated a statistically significant association with T. gondii infection. CONCLUSIONS: Toxoplasmosis was found to be fairly common in pregnant mothers. Proper cat excreta disposal, not eating raw/undercooked meat, maintaining hand cleanliness and following environmental sanitation protocols could be important to decrease T. gondii infection.

Interventions to reduce camel and small ruminant young stock morbidity and mortality in Ethiopia.

Morbidity and mortality of young stock is a challenge for livestock producers globally. In Ethiopia, where camels and small ruminants (sheep and goats) are essential smallholder and pastoral livestock, young stock losses can cause severe consequences to livelihoods. This pilot study, part of a Government-led Young Stock Mortality Reduction Consortium project, was undertaken to identify and evaluate interventions to reduce young stock mortality in mixed crop-livestock and pastoral production systems in Ethiopia. Pastoralists and mixed crop-livestock farmers were enrolled by convenience sampling across four regions. Households were sampled with questionnaire surveys to establish baseline mortality risk and prevalence of diarrhoea and respiratory disease in animals younger than one year, and followed longitudinally over a one-year period, with final evaluations conducted from March to July 2020. Mortality risk and prevalence of diarrhoea and respiratory disease before and after implementation were compared using Poisson regression models including household as random effect. Prior to intervention, median camel mortality, prevalence of diarrhoea, and respiratory disease across production systems in the different households was 0.4, 0.44 and 0.2, respectively. This compared to median pastoralist small ruminant mortality risk and prevalence of diarrhoea and respiratory disease of 0.45, 0.32 and 0.18, respectively. Post-intervention, median camel mortality, prevalence of diarrhoea and respiratory disease dropped to 0.1, 0.08 and 0. Similarly, more than half of the small ruminant households reported no mortality, and no cases of diarrhoea or respiratory disease. In camels, rate ratios of mortality risk, prevalence of diarrhoea, and respiratory disease post-intervention compared to the baseline were 0.41, 0.41 and 0.37. In small ruminants, rate ratios were 0.33, 0.35 and 0.46. All reductions were statistically significant (p < 0.01). Generally, pastoralists experienced higher mortality and disease prevalence compared to mixed crop-livestock smallholders, and the effect of intervention was slightly higher in pastoralist households. The pilot study findings demonstrated highly significant reductions in mortality and risk of diarrhoea and respiratory disease post-interventions. However, not all households benefitted from the interventions, with a few households reporting increased mortality and morbidity. Many households had very few animals which made it challenging to measure impact and the study was conducted over a single year, without a control group, so between year effects could not be accounted for in the reductions observed. These findings should contribute to improved livestock productivity in Ethiopia.

Infection of sheep by Echinococcus multilocularis in Gansu, China: evidence from mitochondrial and nuclear DNA analysis.

BACKGROUND: In the normal life cycle of the parasite (Echinococcus multilocularis) that causes alveolar echinococcosis, domestic and wild carnivores act as definitive hosts, and rodents act as intermediate hosts. The presented study contributes to the research on the distribution and transmission pattern of E. multilocularis in China having identified sheep as an unusual intermediate host taking part in the domestic transmission of alveolar echinococcosis in Gansu Province, China. METHODS: From 2020 to 2021, nine whitish different cyst-like were collected from the liver of sheep in Gansu Province for examination. A near complete mitochondrial (mt) genome and selected nuclear genes were amplified from the cyst-like lesion for identification. To confirm the status of the specimen, comparative analysis with reference sequences, phylogenetic analysis, and network analysis were performed. RESULTS: The isolates displayed ≥ 98.87% similarity to E. multilocularis NADH dehydrogenase sub-unit 1 (nad1) (894 bp) reference sequences deposited in GenBank. Furthermore, amplification of the nad4 and nad2 genes also confirmed all nine samples as E. multilocularis with > 99.30% similarity. Additionally, three nuclear genes, pepck (1545 bp), elp-exons VII and VIII (566 bp), and elp-exon IX (256 bp), were successfully amplified and sequenced for one of the isolates with 98.42% similarity, confirming the isolates were correctly identified as E. multilocularis. Network analysis also correctly placed the isolates with other E. multilocularis. CONCLUSIONS: As a result of the discovery of E. multilocularis in an unusual intermediate host, which is considered to have the highest zoonotic potential, the result clearly demonstrated the necessity for expanded surveillance in the area.

Seasonal prevalence of bovine trypanosomosis and trypanosome species distribution in Jimma Horo district, Oromia regional state, Western Ethiopia.

A study was conducted to determine the prevalence of bovine trypanosomosis in rainy (June 2019) and dry (February 2020) seasons in Jimma Horoo district, Kellem Wollega Zone, Oromia Regional State, Ethiopia. A total of 720 blood samples were examined using buffy coat and thin blood smear techniques. The packed cell volume (PCV) of each animal was determined. The overall bovine trypanosomosis prevalence was 4.3% (χ2 = 1.25, P = 0.26). The prevalence was 5% (95% CI = 4.1-8.3) and 3.3% (95% CI = 2.7-6.3) in the dry and rainy reasons, respectively (P > 0.05). Trypanosoma congolense, T. vivax and T. b. brucei were detected in (60%), (33.3%) and (6.7%) of infected cattle, respectively. The highest trypanosome prevalence was observed in Burka Gudina (7.6%), and the lowest in Melka Nega village (2.1%). There were significant variations between trypanosome prevalence in relation to body condition scores (χ2 = 23.16; P = 0.0.00) of examined cattle. No significant difference (P > 0.05) was observed between seasons, age, and sex categories of cattle. The PCV values of trypanosome infected (22.94%) was significantly lower than non-infected cattle (26.47%) (χ2 = 19.60; (P < 0.05). The prevalence of bovine trypanosomosis in Jimma Horo district was low and it can be controlled by treatment of infected cattle using sanative pairs of trypanocidal drugs with additional application of deltamethrin pour-on in the dry season. Further, in view of poor sensitivity of buffy coat technique used the use of molecular techniques should be encouraged.

Predicting the potential for zoonotic transmission and host associations for novel viruses.

Host-virus associations have co-evolved under ecological and evolutionary selection pressures that shape cross-species transmission and spillover to humans. Observed virus-host associations provide relevant context for newly discovered wildlife viruses to assess knowledge gaps in host-range and estimate pathways for potential human infection. Using models to predict virus-host networks, we predicted the likelihood of humans as hosts for 513 newly discovered viruses detected by large-scale wildlife surveillance at high-risk animal-human interfaces in Africa, Asia, and Latin America. Predictions indicated that novel coronaviruses are likely to infect a greater number of host species than viruses from other families. Our models further characterize novel viruses through prioritization scores and directly inform surveillance targets to identify host ranges for newly discovered viruses.

Reducing Calf Mortality in Ethiopia.

Morbidity and mortality of young stock present economic and production challenges to livestock producers globally. In Ethiopia, calf morbidity and mortality rates, particularly due to diarrhea and respiratory disease, are high, limiting production, incomes, and the ability of farmers to improve their livelihoods. In this paper, we present findings from the combined experience of the Young Stock Mortality Reduction Consortium, which conducted epidemiological and intervention testing in calves across three production systems. This innovative alliance identified Cryptosporidium parvum and E. Coli K99 as the most common causes of diarrhea in pastoral and peri-urban calves; Strongyloides spp. as the most common fecal parasite in mixed crop-livestock and peri-urban calves; and bovine adenovirus, parainfluenza virus-3, and bovine respiratory syncytial virus as the most common respiratory pathogens in peri-urban calves. Furthermore, by improving producer knowledge with respect to fundamental livestock husbandry, feeding, housing, and neonatal care practices, calf mortality risk across production systems was reduced by 31.4 to 71.4% compared to baseline (between 10.5 and 32.1%), whereas risk of diarrhea was reduced by 52.6-75.3% (baseline between 11.4 and 30.4%) and risk of respiratory disease was reduced by 23.6-80.8% (baseline between 3.3 and 16.3%). These findings have informed scaling strategies and can potentially contribute to improved livestock productivity and human livelihoods in Ethiopia.

The magnitude of calf morbidity and mortality and risk factors in smallholder farms across livestock production systems in central Ethiopia.

BACKGROUND: Calf morbidity and mortality are major constraints in Ethiopian cattle production that severely limit available replacement stock. Calf morbidity and mortality reports in Ethiopia mostly focus on market-oriented dairy production systems. A cross-sectional study was undertaken in central Ethiopia with the objectives of estimating the magnitude of calf morbidity and mortality across three production systems and contributing risk factors. METHODS: A cross-sectional study was conducted at pastoral, mixed-crop livestock, and dairy farms in central Ethiopia from February 2019 to June 2019 to collect 1-year retrospective and cross-sectional data on calf morbidity and mortality from smallholder farmers using a structured questionnaire. RESULTS: A total of 293 smallholder farmers were involved in the study. Among the households interviewed, 83% of respondents encountered feed shortages in the year prior to this study. The overall annual calf morbidity prevalence and mortality rate were 6.49% (95% CI: 4.87-8.44) and 10% (95% CI: 8.28-11.93), respectively. Morbidity was higher in Dalocha and Sululta districts in mixed crop-livestock and peri-urban production systems, respectively. Logistic regression analysis of potential risk factors indicated that calf morbidity was associated with the calf and dam body condition score (BCS). Calves with BCS of 3 (medium) were less likely to be morbid (odds ratio [OR]: 0.20 [95% CI: 0.07-0.56]) than calves with BCS of 1 (emaciated), and calves born from dams with a body condition score of 2 (thin) were also at lower risk (OR: 0.25 [95% CI: 0.07-0.95]) than calves born from emaciated dams. The odds of calf mortality in Awash Fentale district were higher (OR: 6.19 [95% CI: 2.09-18.32]) compared to Sululta district. CONCLUSIONS: The study results revealed that the production system and management affect the magnitude of calf morbidity and mortality. We recommend improving water and feed access and resources for livestock owners to reduce calf morbidity and mortality.

Coronavirus and Paramyxovirus Shedding by Bats in a Cave and Buildings in Ethiopia.

Bats are important hosts of zoonotic viruses with pandemic potential, including filoviruses, MERS-Coronavirus (CoV), SARS-CoV -1, and likely SARS-CoV-2. Viral infection and transmission among wildlife are dependent on a combination of factors that include host ecology and immunology, life history traits, roosting habitats, biogeography, and external stressors. Between 2016 and 2018, four species of insectivorous bats from a readily accessed roadside cave and buildings in Ethiopia were sampled and tested for viruses using consensus PCR assays for five viral families/genera. Previously identified and novel coronaviruses and paramyxoviruses were identified in 99 of the 589 sampled bats. Bats sampled from the cave site were more likely to test positive for a CoV than bats sampled from buildings; viral shedding was more common in the wet season; and rectal swabs were the most common sample type to test positive. A previously undescribed alphacoronavirus was detected in two bat species from different taxonomic families, sampling interfaces, geographic locations, and years. These findings expand knowledge of the range and diversity of coronaviruses and paramyxoviruses in insectivorous bats in Ethiopia and reinforce that an improved understanding of viral diversity and species-specific shedding dynamics is important for designing informed zoonotic disease surveillance and spillover risk reduction efforts.

Epidemiology of Porcine Cysticercosis in Eastern and Southern Africa: Systematic Review and Meta-Analysis.

Taenia solium cysticercosis is the most common cause of acquired epilepsy in pig-raising and pork-consuming parts of Africa, Latin America, and Asia. This review aimed to systematically compile and synthesize data on the epidemiology of porcine cysticercosis in the Eastern and Southern Africa (ESA) region. Comprehensive searching strategies were employed to retrieve the studies published or reported between January 1,1997 and March 1, 2021, from Pub Med, Hinari, and Google Scholar databases and search platforms. The identified studies that met the inclusion criteria were then appraised for methodological quality. Finally, 44 studies obtained from nine countries were selected and included in this review. Relevant data were extracted using standardized templates for qualitative synthesis and meta-analysis. The overall pooled prevalence estimate of porcine cysticercosis in the ESA region was 17% (95% CI: 14-20%). The prevalence level between and within countries showed high variability. The pooled estimate showed high heterogeneity among the reports (the inverse variance index value (I2) of 98.99%, p < 0.05). The meta-analysis sub-grouped by the type of diagnostic test showed the pooled prevalence estimate of 27% (95% CI: 9-50) by carcass dissection; 23% (95% CI: 14-33) by Antibody-based immunodiagnostic techniques; 23% (95% CI: 18-29) by antigen detecting (Ag)-ELISA, 12% (95% CI: 7-18) by meat inspection, and 9% (95% CI: 7-11) by lingual examination. The meta-analysis sub-grouped by region showed a relatively higher pooled prevalence estimate for the Southern region 22% (95% CI: 15-30) compared to 13% (95% CI: 11-15) in the Eastern region. The highest country-based pooled prevalence was obtained from South Africa (33%, 95% CI: 20-48) and Zambia (22%, 95% CI: 16-29), whereas the lowest pooled prevalence was identified in Madagascar (5%, 95% CI: 4-5) and Rwanda (7%, 95% CI: 6-8). The lack of latrine, traditional pig husbandry practices, unprotected water sources, and increase in age were identified as significant risk factors for the occurrence of porcine cysticercosis in the pooled studies. The findings of this review will provide context-specific input to prioritize the possible intervention programs for T. solium control in the ESA region. More sensitive and specific test-based prevalence estimates, detailed risk factor investigations, and financial losses analysis are needed to establish feasible control strategies. Systematic Review Registration: http://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021238931.

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

Background: Salmonella is one of the most common foodborne pathogens globally, and it remains a major public health concern with the increasing concern of the emergence and spread of antimicrobial-resistant strains. In Ethiopia, the information on the prevalence of Salmonella is scarce in export abattoirs. Objective: To estimate the magnitude and antimicrobial susceptibility profile of Salmonella recovered from export abattoirs located in East Shewa, Ethiopia. Methods: A cross-sectional study was conducted from January to October 2020. In the study, 345 samples were collected from five export abattoirs using a systematic random sampling method. There were 150 carcass swabs (100 from goats and 50 from sheep), 60 goat skin swabs, 60 knife swabs, and 75 human stools. The isolates were identified and characterized using standard bacteriological procedures and confirmed using Salmonella genus-specific primer by polymerase chain reaction. Isolates were subjected to antimicrobial susceptibility to 14 antibiotics using the Kirby-Bauer disk diffusion method, and the results were assessed by using Clinical and Laboratory Standards Institute 2018. Results: Of the 345 samples, 21 (6.08%; 95% CI 4.9-11.2%) were positive for Salmonella. The specific prevalence of Salmonella in carcass, skin, and knife swabs were 10 (6.67%; 95% CI 3.5-11.19%), 7 (11.67%; 95% CI 5.70-23.00%), and 4 (6.67%; 95% CI 2.50-16.64%), respectively. There was no statistically significant difference in the occurrence of Salmonella among export abattoirs and types of samples (P>0.05). In the current study, Salmonella was not isolated from sheep carcass and human stool samples. Among the 21 Salmonella isolates, 7 (33.3%) were resistant to at least 1 of the 14 antimicrobial agents tested and 2 (9.04%) of isolates were resistant to two antibiotics, tetracycline, and streptomycin. All isolates were susceptible to kanamycin, chloramphenicol, cephalothin, gentamycin, and ceftriaxone. Conclusion: Salmonella was detected in carcass, skin, and knife samples from export abattoirs, which can have serious public health consequences. Some commonly used drugs in veterinary medicine have developed antimicrobial resistance. Therefore, sufficient sanitation at abattoirs, appropriate cooking of carcasses, and rational drug use is strongly advised. Further in-depth study such as serotyping and antimicrobial-resistant gene identification is recommended.

Magnitude of Antibody Cross-Reactivity in Medically Important Mosquito-Borne Flaviviruses: A Systematic Review.

INTRODUCTION: Flaviviruses are a genus of enveloped single-stranded RNA viruses that include dengue virus (DENV), yellow fever virus, West Nile virus (WNV), Japanese encephalitis virus, and Zika virus. Nowadays, diverse serological assays are available to diagnose flaviviruses. However, infection with flaviviruses induces cross-reactive antibodies, which are a challenge for serological diagnosis. OBJECTIVE: This systematic review aimed to assess the magnitude of medically important mosquito-borne flavivirus-induced antibody cross-reactivity and its influence on serological test outcomes. METHODS: This study was designed based on the PRISMA guidelines. It includes original research articles published between 1994 and 2019 that reported serological cross-reactions between medically important mosquito-borne flaviviruses. Articles were searched on PubMed using controlled vocabulary. Eligibility was assessed by title, abstract, and finally by reading the full paper. The articles included are compared, evaluated, and summarized narratively. RESULTS: A total of 2,911 articles were identified, and finally 14 were included. About 15.4%-84% of antibodies produced against non-DENV flaviviruses were cross-reactive with DENV on different assays. Up to 30% IgM and up to 60% IgG antibodies produced against non-WNV flaviviruses were cross-reactive with WNV on EIA assays. The magnitude of antibodies produced against flaviviruses that are cross-reactive with chikungunya virus (Alphavirus) was minimal (only about 7%). The highest antibody cross-reactivity of flaviviruses was reported in IgG-based assays compared to IgM-based assays and assays based on E-specific immunoglobulin compared to NS1-specific immunoglobulin. It was found that preexisting immunity due to vaccination or prior flavivirus exposure to antigenetically related species enhanced the cross-reactive antibody titer. CONCLUSION: This review found the highest cross-reaction between DENV and non-DENV flaviviruses, especially yellow fever virus, and the least between chikungunya virus and DENV. Moreover, cross-reaction was higher on IgG assays than IgM ones and assays based on Eprotein compared to NS1protein. This implies that the reliability of serological test results in areas where more than one flavivirus exists is questionable. Therefore, interpretation of the existing serological assays should be undertaken with a great caution. Furthermore, research on novel diagnostic signatures for differential diagnosis of flaviviruses is needed.

Epidemiological investigation of bovine trypanosomosis in Bedele district, Buno Bedele zone, Oromia regional state, Ethiopia.

A cross-sectional study was conducted in December 2018 in four purposively selected villages of Bedele district, Oromia Regional State, Southwest Ethiopia. The study aimed to determine the prevalence of bovine trypanosomosis and associated risk factors of trypanosome infections in cattle. A total of 384 blood samples were collected from systematically selected cattle and examined using buffy coat and thin blood smear examination methods. The overall prevalence of bovine trypanosomosis was 8.3%. Trypanosoma congolense (68.8%) and T. vivax (31.2%) were the prevailing trypanosome species identified in the area. A statistically significant difference (P < 0.05) was observed in the prevalence of bovine trypanosomosis between body condition scores of cattle. The prevalence of bovine trypanosomosis was slightly higher in female (9%) as opposed to male (7.3%) cattle, but the difference was not statistically significant (P > 0.05). Similarly, no statistically significant difference (P > 0.05) was observed between age categories of cattle. The mean PCV value of trypanosome infected cattle (21.4 ± 3.6) was significantly (P < 0.05) lower than that of non-infected (25.6 ± 4.6). The current study indicated that, despite vector control measures implemented for several years, bovine trypanosomosis persists and continues to be a core problem to cattle health and production in the Bedele district. Therefore, more attention should be given to control the disease and its vectors based on temporal and spatial distribution. Also, the use of molecular techniques should be encouraged in view of their greater sensitivity when compared to the buffy coat method.

Bovine trypanosomosis: Prevalence and vector distribution in Sadi Chanka district, Kellem Wollega zone, Oromia regional state, Ethiopia.

Bovine trypanosomosis remains an important livestock disease constraint, which is threatening livestock health and production, despite ongoing tsetse and trypanosomosis control efforts in Sadi Chanka district, Kellem Wollega zone, Oromia regional state, Ethiopia. A cross-sectional study was conducted in May 2018, to determine the prevalence of bovine trypanosomosis and distribution of the vectors of disease in Sadi Chanka district, Western Ethiopia. A total of 370 blood samples were collected from randomly selected local Horro and Abigar cattle breeds covering five villages of the district. The collected samples were examined using buffy coat microscopy and Giemsa-stained thin blood smear techniques. In this study, 12.4% (95% CI: 12.3-12.4) of the animals were found to be infected with trypanosomes. The study showed that 69.6% of trypanosome infections were caused by T. congolense followed by 26.1% T. vivax and 4.3% mixed T. congolense and T. vivax. In the present study, the association of bovine trypanosomosis was assessed in releation to body condition scores, sex, and age of cattle, and a significant association (P < 0.05) was observed between body condition scores. However, significant differences were not observed between sex and age categories (P > 0.05). The Mean Packed Cell Volume (PCV) of infected (21.6%) and non-infected (24.5%) groups of cattle had significant variation (P < 0.05). In an entomological survey, a total of 616 flies were trapped, of which 280 (45.5%) were Glossina and the remaining 336 (54.5%) were Stomoxys, Tabanus, and Haematopota. The apparent density of Glossina, Stomoxys, Tabanus, and Haematopota was 3.5, 3.1, 0.7 and 0.4 fly per trap per day, respectively. This study generated basic scientific data on the epidemiology of bovine trypanosomosis and its vectors in Sadi Chanka district, which can be used in planning the control of bovine trypanosomosis in the area.

Bovine trypanosomosis in upstream and downstream of Ghibe-III hydroelectric dam: parasitological and entomological study, southern Ethiopia.

Two-point cross-sectional study design in dry and rainy seasons was employed near Ghibe-III Dam from December 2018 to July 2019. Trypanosomosis prevalence comparison between downstream (Kindodidaye) and upstream (Loma districts), associated risk factors, vector dispersion, identification and vector infection rate considered. Blood sample collected from 1280 cattle from two districts during dry and rainy seasons; the assumed risk factors recorded. Samples were examined using heamatological and parasitological techniques. In this study 9.1% (116/1280) trypanosomosis prevalence recorded. Prevalence was significantly (p < 0.05) different between Kindodidaye (11.7%) and Loma (6.4%). Most of the infections were due to T. congolense (79.3%) followed by T. vivax (17.2%) and T. brucei (2.6%) and one mixed infection recorded. Significant (p < 0.05) difference observed in season, within district and between districts. Among the assumed risk factors: district, season, Kebele and body condition score showed significant (p < 0.05) difference; whereas sex, age, color weren't significantly (p > 0.05) different. Significantly (p < 0.05) low mean PCV observed in infected group, dry season and Kindodidaye district. Entomological survey revealed 1030 tsetse spp. (G. pallidipes and G. fuscipes) and 2045 biting flies mainly Stomoxysis and Tabanus, and other unidentified spp. recorded. Tsetse apparent density were significantly (p < 0.05) high in Kindodidaye and rainy season with value of 5.3 and 7.1 F/T/D, respectively. Out of 182 tsetse fly dissected twenty seven (14.6%) of them were infected. A proportion of 23.0%, 30.8% and 46.2% infection rate recorded in proboscis, salivary gland and mid gut, respectively. The study shows Kindodidaye and rainy season had high trypanosomosis and tsetse apparent density than Loma. The difference might be associated with water reserve created due to Ghibe III hydroelectric dam and this could be a golden opportunity in the area to contribute tsetse control program. Stakeholders' need to aware to use this opportunity before tsetse adapts itself into new environment or niche for their survival.

Prevalence of bovine abortion, calf mortality, and bovine viral diarrhea virus (BVDV) persistently infected calves among pastoral, peri-urban, and mixed-crop livestock farms in central and Northwest Ethiopia.

BACKGROUND: Bovine Viral Diarrhea virus (BVDV) is one of important diseases of cattle worldwide causing economic losses to the cattle industry primarily due to increased premature culling and decreased reproductive performance. The virus can cross the placenta during early pregnancy and result in the birth of persistently infected (PI) calves that are efficient transmitters of BVDV and serving as the primary reservoirs for BVDV. Relatively few studies have focused on understanding BVDV seroprevalence, virus detection, genotyping and its distribution in Africa. Most BVDV research in Ethiopia has involved serologic surveys in adult cattle, rather than the identification of PI calves, despite their role in viral shedding and recurring infections. A cross-sectional study was undertaken in three different livestock production systems of Ethiopia with the objective to estimate the prevalence of bovine abortion, calf mortality, and BVDV persistently infected calves. RESULTS: Ear notch samples (882) collected from calves in 349 households were tested for BVDV antigen using antigen capture enzyme-linked immunosorbent assay (ACE). All samples tested were negative for BVDV antigen. The overall animal level crude abortion and calf mortality prevalence were 4.0% (95% CI: 2.9-5.2) and 9.2% (95% CI: 7.7-11.0) respectively. The lower BVDV PI prevalence may be due to a lower effective contact rate between cattle reared in small-scale extensive production systems in Ethiopia. CONCLUSIONS: This is the first report of BVDV Ag test in Ethiopia and no PI was detected in calves in the study areas. Since BVDV is a disease of great economic importance, this study finding must be interpreted with care since absence of evidence is not evidence of absence and even a single BVDV infected animal can serve as source of infection and contribute to the persistent spread of the virus. Greater attention needs to be given to screening for PI animals through testing large number of animals and culling positive animals. Hence, future research should focus on regions and production systems with high BVDV seroprevalence followed by antigen ELISA or BVDV real-time PCR to detect persistently infected and acutely viremic animals.