Epidemiology of Epizootic Lymphangitis Among Carthorses in Ethiopia

Prevalence and risk factors for epizootic lymphangitis among equids in ethiopia during 2002-2023: A systematic review and meta-analysis

In Sub-Saharan Africa (SSA), particularly in Ethiopia, Epizootic Lymphangitis (EL) is the most prevalent fungal disease of equids, which causes significant economic losses as well as a decrease in equid populations. Therefore, this systematic review and meta-analysis were designed to pool the results of individual studies and estimate the prevalence of EL among equids in Ethiopia. A systematic search of research articles on the prevalence and risk factors of EL among equids in Ethiopia was conducted in registers, databases, and other sources. Cochrane's Q, inverse variance (I2), sensitivity analysis, funnel plot, Begg's, and Egger's regression tests were used to check heterogeneity and publication bias. A random-effects model was used to calculate the pooled burden of EL among equids. For this meta-analysis, a total of 7217 equids were included in the 14 eligible studies. The overall pooled prevalence of EL among equids in Ethiopia was 20.24% (95% CI: 16.27, 24.21). According to the subgroup analysis, the highest prevalence was observed in cart horses (20.98%), the Amhara region (21.46%), and studies conducted using sample sizes of 384 equids or greater (24.67%) and from 2002 to 2018 (25.52%) study periods. Harness-inflicted wounds, sharing stables or yards with harnesses, and the presence of preexisting wounds were identified as factors significantly associated with EL magnitude. Early diagnosis and proper medication, as well as implementing appropriate prevention and control measures, are necessary for the management of EL in equids.

Ulcerative and Spreading Nodular Lesion of Epizootic Lymphangitis in Adult Black Horse in Gondar, Ethiopia: Case Report and Wound Treatment

An adult male black horse was presented to the UOG veterinary clinic with swelling, discharge, and skin wounds on the chest wall and the right front leg; then, it goes to the lateral and medial hind leg. Inspection and palpation were carried out, and we revealed that the skin was swelled, thickened and hard on clinical examination. There was also nodule rupture, and discharge on the limb and chest skin. Different therapy was applied starting from washing the wound with water-diluted potassium permanganate and then 0.9% NaCl together with paraffin topically placed on the wound. 10% povidone-iodine was also applied by using gauze. Griseofulvin 750 mg/day for one week was given as antifungal therapy orally. The prognosis was poor due to the long incubation period and high resistance of the causative agent.

Growth inhibitory effect of selected medicinal plants from Southern Ethiopia on the mycelial phase of Histoplasma capsulatum var. farciminosum

BACKGROUND

Epizootic lymphangitis is an infectious and chronically debilitating disease of the equines. Histoplasma capsulatum var. farciminosum, a thermally dimorphic fungi, is the causative agent for the disease. In Ethiopia, the disease significantly affects carthorses, posing threats to animal welfare, and resulting in substantial economic losses. Limited availability of widely accessible antifungals in addition to the chronic nature of the disease is the major challenge against management of epizootic lymphangitis. This study aimed to assess the in vitro efficacy of specific local medicinal plant extracts against the mycelial phase development of H. capsulatum var. farciminosum in southern Ethiopia. The leaves of Xanthium strumarium, Kanda (Family Rubiaceae), Croton macrostachyus (Bisana in Amharic), and Centella Asiatica (Echere waye as a local name in Zeyissegna) that are traditionally used for the treatment of different skin ailments were collected and extracted for the in vitro trial.

RESULTS

The study revealed that methanol extracts of Xanthium strumarium, Kanda, Croton macrostachyus, and Centella Asiatica, at minimum inhibitory concentrations of 1.25 mg/ml, 2.5 mg/ml, 2.5 mg/ml, and 5 mg/ml, respectively, inhibited the growth of H. capsulatum var. farciminosum.

CONCLUSION

This in vitro finding could serve as significant preliminary data in the exploration of effective alternative treatment options for epizootic lymphangitis. This study provides a crucial foundation for further research aimed at determining the chemical components and in vivo effectiveness of these plant extracts against both the mycelial and yeast forms of Histoplasma capsulatum var. farciminosum.

The socioeconomic impact of equine epizootic lymphangitis in working equids in low and middle-income countries: A scoping review

Equine epizootic lymphangitis (EEL) is a very infectious and contagious fungal disease that, with its ocular, respiratory and skin forms, causes severe effects on the health and welfare of working equids. Treatment is expensive and rarely available in low and middle-income countries (LMICs). Epidemiological data is lacking in most countries where the disease is known to exist. The purpose of this scoping review is to identify the current knowledge on the socioeconomic impact of EEL in working equids in LMICs, to highlight knowledge gaps and provide recommendations for future research. Seven eligible papers were obtained from the search of four databases and backward citation searching. The review showed that the available research on this subject is very scarce and restricted to Ethiopia. From the results it emerged that EEL causes detrimental socioeconomic effects on working equids' owners, compromising their health and livelihood. Its economic consequences were attributed to the reduced working capacity and loss of sick animals. Among the social impacts, authors highlighted the stigma around sick equids and their owners. Further studies on the socioeconomic impact of EEL conducted in endemic areas are highly required. The integration of epidemiological data with socioeconomic impact studies from LMICs may promote funding allocation for the development of cost-effective treatments and vaccines and for implementing disease prevention and control programmes. Future research would gain from applying the One Health approach to better examine the multiplicity of the disease socioeconomic effects, therefore increasing the potential of research to orientate policy.

The Socioeconomic Impact of Diseases of Working Equids in Low and Middle-Income Countries: A Critical Review

Working equids provide a crucial contribution to the livelihoods and food security of communities in low- and middle-income countries (LMICs). Nevertheless, they are a neglected category within animal health policies and interventions of governmental and non-governmental institutions. This critical review aims to assess the socioeconomic impact of diseases of working equids in LMICs. By highlighting the implications of diseases on working equid welfare, human wellbeing and livelihoods, this review seeks to sensitise policymakers within governments and international organisations to develop policies and interventions aimed at protecting the health of working equids and, consequently, the health and livelihoods of their dependent communities. Twenty relevant publications were identified through the search of five databases (CAB Abstracts, Web of Science Core Collection, BIOSIS, EMBASE and Scopus), backward citation searching and screening of indexes of proceedings and Special Issues retrieved from the database search. The review findings show that diseases of working equids have detrimental socioeconomic effects. However, this subject is under-researched and restricted to few diseases and geographical settings. Considering the complexity of the issue, this review demonstrates that the 'One Health' approach represents an opportunity to clarify the link between equid health, human wellbeing and livelihoods, facilitating the translation of research into policy.

Striving towards access to essential medicines for human and animal health; a situational analysis of access to and use of antifungal medications for histoplasmosis in Ethiopia

Antifungal medications are vital in combatting fungal diseases that affect over a billion people annually. Antifungal medications for people and equids are scarce in Ethiopia, where lack of resources to treat fungal infection, in particular histoplasmosis, is a major health challenge. Histoplasmosis is endemic within the equine population in Ethiopia, where it is estimated that one in five horses are infected. This disease has far reaching impacts on equine welfare and the socio-economic wellbeing of families. The burden of histoplasmosis in people in Ethiopia is currently unknown, representing a blind spot in public health surveillance. Previous research has identified contact with wildlife, and domestic animal species as possible transmission pathways for histoplasmosis however, questions remain about the role of equids in human histoplasmosis. Given the close proximity of people and animals in this setting, the high level of endemic disease among equids, and the common sources of anti-fungals in Ethiopia, our study adopted a One-Health approach to examine how systemic issues affect access to, and use of antifungals to treat histoplasmosis among people and equids. A qualitative study was conducted in 6 urban regions of Oromia, Ethiopia in December 2018, incorporating semi-structured face-to-face interviews and focus group discussions. Twenty-seven individual interviews were held with doctors (n = 7), pharmacists (n = 12), veterinarians (n = 5), para-veterinarians (n = 2) and an equid owner (n = 1). Eleven focus groups were conducted with equid owners (n = 42), 3 with veterinarians (n = 6), 1 with para-veterinarians (n = 2) and 1 with pharmacists (n = 2). Transcripts were analysed using thematic analysis, and dimensions of key themes conceptualised and compared. Two overarching themes namely, 'Structural', and 'Human factors', summarised the main limitations to access to antifungal medications. 'Structural factors' included the national reliance on importation of medicines or pharmaceutical ingredients, inaccurate demand forecasting due to poor recording of the shortfall within the pharmaceutical supply chain, deficiencies in diagnostic capacity for fungal disease and, a healthcare system funded with a significant component of out-of-pocket expenditure. 'Human factors' that influenced access to antifungals included the perception of the expense of antifungals compared with competing needs such as food and education, the social stigma attached to histoplasmosis that could lead to delays in treatment seeking and, readily available home remedies or alternative treatment options. Furthermore, it was reported that trust in healthcare and veterinary provisions was undermined by a perceived lack of efficacious medications. Access to antifungals remains an urgent public health and animal welfare concern in Ethiopia. Key points within the supply and distribution chain that affect access to anti-fungals are identified, and policies that facilitate anti-fungal procurement and distribution should be reviewed. This paper highlights the structural, socio-economic and cultural factors influencing the management of infection with histoplasmosis, including how it is understood, identified and treated. This study identifies areas where further cross-sectorial work is needed to address these factors to improve disease control and clinical outcomes observed in human and animal histoplasmosis within Ethiopia.