Aman et al. BMC Veterinary Research (2020) 16:185 https://doi.org/10.1186/s12917-020-02411-6 RESEARCH ARTICLE Open Access Spatial and temporal distribution of foot and mouth disease outbreaks in Amhara region of Ethiopia in the period 1999 to 2016 Endris Aman1, Wassie Molla2* , Zeleke Gebreegizabher3 and Wudu Temesgen Jemberu2 Abstract Background: Foot and mouth disease (FMD) is an economically important trans-boundary viral disease of cloven- hoofed animals. It is caused by FMD virus, which belongs to the genus Aphthovirus and family Picornaviridae. FMD is a well-established endemic disease in Ethiopia since it was first detected in 1957. This retrospective study was carried out to identify the spatial and temporal distribution of FMD outbreaks in Amhara region of Ethiopia using 18 years (January 1999–December 2016) reported outbreak data. Results: A total of 636 FMD outbreaks were reported in Amhara region of Ethiopia between 1999 and 2016 with an average and median of 35 and 13 outbreaks per year respectively. In this period, FMD was reported at least once in 58.5% of the districts (n = 79) and in all administrative zones of the region (n = 10). The average district level incidence of FMD outbreaks was 4.68 per 18 years (0.26 per district year). It recurs in a district as epidemic, on average in 5.86 years period. The incidence differed between administrative zones, being the lowest in East Gojjam and highest in North Shewa. The occurrence of FMD outbreaks was found to be seasonal with peak outbreaks in March and a low in August. The long-term trend of FMD outbreaks indicates a slight, but statistically significant (p < 0.001) decrease over the study period. Conclusion: FMD occurred in all zones of the region and showed statistically significant decrease in the long-term trend. Numbers of outbreaks were relatively higher during dry season. The spatial and temporal distribution identified in this study should be considered in controlling the disease. As unregulated and frequent animal movements are the likely causes of high outbreak occurrence during the dry season, animal movement regulations should be considered for the long-term control of FMD. Keywords: Amhara region, Ethiopia, FMD, Outbreak, Spatial, Temporal * Correspondence: [email protected] 2College of Veterinary Medicine and Animal sciences, University of Gondar, P.O.BOX 196, Gondar, Ethiopia Full list of author information is available at the end of the article © The Author(s). 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Aman et al. BMC Veterinary Research (2020) 16:185 Page 2 of 8 Background progressive control pathway (PCP). Ethiopia has been Foot and mouth disease (FMD), is an economically identified to be in stage one of the FMD progressive important trans-boundary viral disease of cloven- control pathway. The progressive control path way re- hoofed animals. Foot and mouth disease virus quires detail epidemiological studies to locate and iden- (FMDV), the cause of the disease, belongs to the tify the spatiotemporal distribution of FMD in the genus Aphthovirus and family Picornaviridae.The country to progress to the next stage. In spite of a num- virus affects a wide range of hosts including domes- ber of sero-prevalence studies conducted in different re- tic and wild ruminants and pigs. According to OIE gions of Ethiopia, there are no studies that investigated (World Organization for Animal Health), FMD was the spatial and temporal distribution of FMD, particu- the first viral infection of animals recognised and larly in Amhara region. Therefore, this study was under- ranks first among the diseases of animals [1]. FMD taken with the objective of identifying the spatial and is one of the most important livestock diseases re- temporal distribution of the reported outbreaks of FMD sponsible for the loss of production and productivity, from January 1999 to December 2016 in Amhara region trade embargoes and huge control costs across the of Ethiopia. globe [2]. FMDV has seven distinct serotypes: A, O, C, and Results South African Territories (SAT) 1, SAT 2, SAT 3, and Incidence of FMD outbreaks Asia 1. Each serotype has many biotypical strains and to- A total of 636 FMD outbreaks were reported in Amhara potypes, with incomplete cross protection [3, 4]. Of region of Ethiopia between 1999 and 2016 with an aver- these seven serotypes, serotype O and A have the broad- age and median of 35 and 13 outbreaks per year respect- est distribution in Africa [5, 6]. The occurrence of FMD ively. In this period, FMD was reported at least once in due to serotype C seems decreasing in recent time. Sero- 58.5% of the districts (n = 79) and in all administrative type C occurrence was reported for the last time in zones of the region (n = 10). Majority of the outbreaks Kenya in 2004 and in Ethiopia in 2008 [7, 8]. were from North Shewa zone (44%), South Wollo zone In Ethiopia, FMD is a well-established endemic disease (18.5%), West Gojjam zone (11.16%) and Awi zone (7%) since its detection in 1957 for the first time [9, 10]. Pre- (Additional file 1: Fig. S1). The average incidence of vious studies in the country reported FMD in different FMD outbreaks at district level was 4.68/18 district years animal species with different prevalence levels. For ex- or 0.26/ district year. ample, in cattle they reported FMD prevalence that The reoccurrence of FMD outbreak in the districts of ranges from 1.4 to 53.6% at animal level and up to 61% Amhara region varies from 1 to 17 years. The average at herd level [11–13], in domestic small ruminants 4 to time for the reoccurrence of the disease in the same dis- 11%, and in ungulate wildlife 30% [14, 15]. Among the trict is 5.86 years. The time between outbreaks was known FMD serotypes, four serotypes (A, O, SAT 1 and shorter in districts of West Gojjam, Oromia, North SAT 2) are maintained endemically in Ethiopia. Pub- Wollo and Awi zones and a bit longer in districts of lished articles on FMD show that type A and O are the other six zones. main serotypes responsible for significant economic losses in the country [6, 8, 16]. Geographical distribution of FMD outbreaks In recent times, there is an interest to control FMD in The geographical distribution of the 18 years FMD out- Ethiopia to boost its live animal and meat exports as the breaks within the Amhara region is depicted in Fig. 1. disease is considered the main obstacle to the inter- FMD has been reported from all zones (n = 10) of Am- national trade of livestock and their products [17]. How- hara region during the period 1999–2016. The outbreak ever, controlling of FMD in endemic developing incidence mapped by the administrative zones showed countries in general and in Ethiopia in particular is not that the eastern part of the region was more affected by an easy task due to several reasons. These include the FMD outbreak than the western part (Fig. 1). The FMD wide distribution of multiple serotypes and subtypes, outbreak incidence was above the average incidence of and the presence of diverse hosts of the virus across the the region in North Shewa (12.2/18 district years), South country, uncontrolled livestock movement and shortage Wollo (6.6/18 district years) and West Gojjam (5.5/18 of effective and affordable FMD vaccines in sufficient district years). quantities in the country. Besides, FAO and OIE advo- cate that the control of FMD in endemic countries like Temporal trends of FMD outbreak occurrences in Amhara Ethiopia has to be carried out in a long-term progressive region risk reduction approach [18, 19]. In the period of January 1999 to December 2016, high Currently, in Ethiopia, there is planning towards a na- number of FMD outbreaks were reported in 1999 (n = tional FMD control program, which is a part of 173 outbreaks), 2001 (n = 102), 2004 (n = 76) and 2012 Aman et al. BMC Veterinary Research (2020) 16:185 Page 3 of 8 Fig. 1 Zonal distribution of FMD outbreaks per 18 district years in Amhara region over the period 1999–2016 (we created the map by QGIS version 3.10.2 (a Coruna) software (https://qgis.org/en/site/forusers/download.html)) (n = 85) while the lowest number of outbreaks were re- of outbreaks shows higher frequency of outbreaks in the ported in 2006 (n = 3) (Fig. 2, Additional file 2: Table dry season months compared to other seasons, which S1and Additional file 3: Table S2). The highest number demonstrates statistically significant seasonality of FMD of outbreaks were reported in the month of March (n = outbreaks (Fig.