In North Africa, the livestock population is estimated to be about 7 million large ruminants and 75 million small ruminants (>12% of the small ruminant population of Africa). In this region, the movements of animals – especially at the borders – are frequent, regular and conducted mainly informally. Figure 1 illustrates the main patterns of the animal movements occurring in North Africa region since centuries for social, economic and religious purposes as well as the pathways of the recent incursions of different FMD strains in North Africa based on the samples analysed by OIE reference laboratories. The Figure highlights the fact that the zone ranging from Libya to Morocco – known to have high degree of borders porosity – could be considered as a unique epidemiological unit since these countries share a common risk factor, such as the animal movements without an effective traceability system in place.

The figure highlights as the corridor from Middle East to North Africa (via Egypt and Libya) was in the recent years permeable to the introductions of FMD strains in 2009, 2010 and 2013 coming from Western Asia continent. Although in the Middle East there are countries that mainly import animals, it should not be neglected the degree of connectivity of the animal's movement occurring between Middle East and North Africa (via Egypt and/or via Libya). Further introductions have occurred from East African countries. This pattern of incursions - at least in part - overlaps with the high concentration of animal movements entering into Egypt and Libya from Ethiopia, Chad, Niger and Sudan.

Based on the OIE immediate notifications, foot and mouth disease reoccurred in Tunisia (April 2014), Algeria (July 2014 and March 2015) and Morocco (October 2015) creating the major significant sanitary event in the North African region in the recent times. While recognising the presence of the disease in the neighboring countries such as Mauritania, Libya and Egypt (endemic vs intermittent reoccurrences), this disease was absent in these three countries in the period ranging from 1999 to 2014. The foot and mouth disease viruses - isolated from the outbreaks occurred in Tunisia, Algeria and Morocco (during the period 2014-2015) - were classified within serotype O, and the phylogenetic analysis on VP1 coding sequences revealed that these viruses belong to the Ind-2001 lineage within the Middle East-South Asia (ME-SA) topotype. The O/ME-SA/Ind-2001 lineage was initially identified in the Indian subcontinent in 2001 and subsequently became the predominant lineage in the region. Escape of this lineage from the Indian subcontinent has occurred sporadically, up to 2013, when viruses from outbreaks in Libya (September to November 2013) and Saudi Arabia (August to November 2013) were found to belong to the O/ME-SA/Ind-2001 lineage and phylogenetic analyses showed these viruses are most closely related to viruses from India, Nepal and Bhutan collected in 2013. These laboratory results provided evidence that a new FMD virus was introduced into Libya and that FMD outbreaks in Libya and Saudi Arabia have arisen through separate introduction of this virus in these two countries (Knowles et al, Transboundary and Emerging Diseases 2016, Valdazo-Gonzalez et al., 2014). To corroborate these results, there was an epidemiological investigation carried out by the Libyan Veterinary Services soon after the discovery of the new FMD serotype in their territory. This led to the conclusion that Libya used to import goats from the Middle East by plane and noting that goats were first imported from the Indian continent to Middle East and then (after only 24 hours stopping in Middle East) loaded in the plane to be exported to Libya. Figure 2 illustrates the potential pathway of the introduction of FMD strain O/ME-SA/Ind-2001 in North Africa via Libya in 2013. Owing to the long-standing interrelated animal movements - in particular between Libya, Tunisia, Algeria and Morocco - this exotic lineage of FMD introduced in Libya in 2013 spread, in turn, first to Tunisia (total outbreaks in 2014=142) then to Algeria (total outbreaks in 2014= 419 and a total outbreaks in 2015=12) and finally reached Morocco (total outbreaks in 2015=6) (Figure 3).

Based on the phylogenetic analysis carried out on both VP1 and full genome sequences of the viral isolates obtained from Tunisia, Algeria and Morocco, the following major indications were reflected for the FMD epidemic occurred in 2014-2015 (Pezzoni et al., 2016):

• A unique introduction of the FMDV O/Ind-2001 lineage occurred in North Africa, in Libya in 2013, as suggested by evidence that all Libyan isolates share a common ancestor (estimated to be originated in July 2013);
• There was a single introduction from Libya into the Little Maghreb (Tunisia, Algeria and Morocco). In fact, all the Maghreb isolates were shown to derive from a unique putative common ancestor, estimated to be present since beginning of 2014;
• In Tunisia, the virus evolved in three main clusters, probably consistent with animal movements in the country;
• Two different introductions from Tunisia to Algeria have likely occurred, in 2014 and 2015 respectively; in fact, Algerian isolates from 2014 and those from 2015 cluster in different branches, together with different Tunisian isolates;
• The Moroccan isolate derived from viruses of the 2015 Algerian outbreaks, with which it shares a common ancestor.

However, major challenges were encountered to control the disease in North Africa:

• Difficulties to control animal movements;
• Difficulties in having immediate availability of appropriate vaccine;
• Absence - between countries - of an appropriate regional FMD vaccination strategy and other control measures (e.g. harmonised surveillance plans, stamping-out policy);
• Political instability occurring in Libya and the unknown animal health sanitary situation present in Libya. The latest available information on FMD is dated back to 2013. Tunisia established – for security reasons – a military zone at the border with Libya and animals coming from Libya and entering this restricted area are confiscated and – when serologically positive for FMD – are slaughtered. In 2016, about 6.000 animals coming from Libya were confiscated by Tunisia and 20% of them tested positive for FMD at the 3ABC ELISA test.

As mentioned, the control measures applied by the three countries (Algeria, Tunisia and Morocco) to face the incursion of the FMD strain O/ME-SA/Ind-2001 were different among the countries. However, the vaccination – although applied differently (see Table 1) – was the main control measure that reduced the virus circulation of FMD strain O/ME-SA/Ind-2001 and the related clinical disease manifestation, mainly in cattle population.

Table 1. Vaccination strategies against FMD in the Maghreb region

The Table 2 shows the FMD serotypes that circulated in the Maghreb Region since the 1960s.

Table 2. History of FMD in the North Africa Region

1. Knowles NJ, Bachanek-Bankowska K, Wadsworth J, Mioulet V, Valdazo-González B, Eldaghayes IM, Dayhum AS, Kammon AM, Sharif MA, Waight S, Shamia AM, Tenzin S, Wernery U, Grazioli S, Brocchi E, Subramaniam S, Pattnaik B, King DP. Outbreaks of Foot-and-Mouth Disease in Libya and Saudi Arabia During 2013 Due to an Exotic O/ME-SA/Ind-2001 Lineage Virus. Transbound Emerg Dis. 2016 Oct;63(5):e431-5. doi: 10.1111/tbed.12299. Epub 2014 Dec 7.

2. Valdazo-Gonzalez, B., N. J. Knowles, and D. P. King. Genome sequences of foot-and-mouth disease virus O/ME-SA/Ind-2001 lineage from outbreaks in Libya, Saudi Arabia, and Bhutan during 2013. Genome Announc. 2014 Apr 10;2(2). pii: e00242-14. doi: 10.1128/genomeA.00242-14.

3. Pezzoni Giulia, Calzolari Mattia, Sghaier Soufien, Madani Hafsa, Chiapponi Chiara, Grazioli Santina, Bakkali Labib, Anthony Remy, Brocchi Emiliana. Bayesian evolutionary analysis of FMD viruses collected from outbreaks that occurred in Maghreb regions during 2014-2015. Pg.55. 27-29 September 2016, X° Annual Meeting Epizone – Madrid, Spain.

4. G. Pezzoni, M. Calzolari, S. Sghaier, H. Madani, C. Chiapponi, S. Grazioli, A. Remy, L. Bakkali, E. Foglia, E. Brocchi. Antigenic and evolutionary analysis of FMD viruses from the 2014-2015 outbreaks in the Maghreb region.pg.67, Open Session of the Standing Technical and Research Committees of the European Commission for the Control of Foot-and-Mouth Disease OS'16. Cascais, Portugal. 26th-28th October 2016.