Short Communication First serological investigation of peste-des-petits-ruminants and Rift Valley fever in Tunisia Emna Ayari-Fakhfakh a , Abdeljelil Ghram a , Ali Bouattour a , Imen Larbi a , Latifa Gribâa-Dridi a , Olivier Kwiatek b , Michèle Bouloy c , Geneviève Libeau b , Emmanuel Albina b , Catherine Cêtre-Sossah b, * a Institut Pasteur de Tunis 13, Place Pasteur, B.P. 74, 1002 Tunis Belvédère, Tunisia b CIRAD, UMR Contrôle des Maladies, Montpellier F-34398, France c Institut Pasteur, 25 Rue du Dr. Roux, F-75724 Paris Cedex 15, France article info Article history: Accepted 16 January 2010 Available online xxxx Keywords: Peste-des-petits-ruminants Rift Valley fever Vectors Tunisia abstract This study, carried out between September 2006 and January 2007, is the first cross-sectional serological investigation of peste-des-petits-ruminants (PPR) and Rift Valley fever (RVF) in Tunisia. The objective was to assess the potential need to develop a dual, recombinant PPR–RVF vaccine and how such a vaccine might be utilised in Tunisia. An overall PPR seroprevalence of 7.45% was determined, a finding supported by the high specificity (99.4%) and sensitivity (94.5%) of the ELISA used. On assessment of the diversity and density of mosquitoes in the sampling area, four species of RVF-vectors of the genus Aedes and Culex were identified. However, no serological evidence of RVF was found despite the use of a highly sensitive ELISA (99–100%). Larger scale investigations are underway to confirm these findings and the continuation of the emergency vaccination program against these two diseases remains valid. Ó 2010 Elsevier Ltd. All rights reserved. The ongoing, un-regulated movement of livestock between Algeria and Libya poses a risk to the health of animals in interven- ing Tunisia, in particular to diseases such as peste-des-petits-rumi- nants (PPR) and Rift Valley fever (RVF). In consequence, the development and use of a dual, recombinant capripox vector vac- cine against these diseases has been proposed (Faye et al., 2007). To determine the current prevalence of these diseases in Tunisia a cross-sectional serological study was conducted in six regions considered high-risk areas for PPR and RVF because of their ecol- ogy and livestock density. A total of 610 serum samples were ran- domly collected from animals near water sources between September 2006 and January 2007 (Table 1). Serological analysis was carried out at the Pasteur Institutes at Tunis and Paris and at CIRAD Montpellier, France. To assess the seroprevalence of PPR, blood samples from 263 sheep and 119 goats were analysed by competitive ELISA as previ- ously described (Libeau et al., 1995). In addition, 28 lung samples harvested from slaughtered animals (25 sheep; 3 goats) from dif- ferent regions were tested using a PPR virus-specific RT-PCR (Cou- acy-Hymann et al., 2002). All sera were also analysed using a RVF competitive ELISA as previously described (Paweska et al., 2005). In order to assess the extent and prevalence of potential mosquito vectors, larvae from potential breeding sites in each region (the main wetland areas), were collected and identified. Statistical anal- ysis was carried out using Winepiscope software (De Blas et al., 2000). The overall apparent seroprevalence of PPR was 7.6% (95%, con- fidence interval, CI, 4.9–10.1), a finding supported by the high specificity (99.4%) and sensitivity (94.5%) of the ELISA (Libeau et al., 1995). The Kairouan (95%, CI 8.7–22.3) and Kebili (95%, CI 3.1–20.9) regions had the highest seroprevalence, a finding that was not unexpected given the abundant animal movement within these areas (Table 2). The difference in seroprevalence between goats (11.8%) and sheep (5.7%) was statistically significant (v 2 = 4.3, 1df, P = 0.04), which was consistent with the pathogene- sis of PPR in these species. The lung samples were all negative on RT-PCR (Couacy-Hymann et al., 2002). Although this is the first serological evidence of PPR in Tunisia, no clinical signs were reported in the sampled animals. The similarity in clinical presentation between PPR with other diseases such as bluetongue and sheep-pox, endemic in Tunisia, may account for this finding (Ozmen et al., 2009). In our serological assessment of RVF, given an assumed preva- lence of at least 1% (CI 99.5%), a sample size of 527 was required to detect at least one positive animal. This number was considered as an indicator given our sampling was not random but focused on high-risk areas. All of the 610 samples tested were found negative (De Blas et al., 2000). Since the ELISA we used to screen for RVF is highly sensitive (99–100%) (Paweska et al., 2005) we concluded 1090-0233/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.tvjl.2010.01.007 * Corresponding author. Tel.: +33 467 593911; fax: +33 467 593798. E-mail address: catherine.cetre-sossah@cirad.fr (C. Cêtre-Sossah). The Veterinary Journal xxx (2010) xxx–xxx Contents lists available at ScienceDirect The Veterinary Journal journal homepage: www.elsevier.com/locate/tvjl ARTICLE IN PRESS Please cite this article in press as: Ayari-Fakhfakh, E., et al. First serological investigation of peste-des-petits-ruminants and Rift Valley fever in Tunisia. The Veterinary Journal (2010), doi:10.1016/j.tvjl.2010.01.007