pathogens intrusion. Blackleg (1970, 1995) and the contagious ecthyma (1999) were probably introduced into the country by live ruminants imported from Madagascar (9). Since 2002, importation of live animals from Tanzania has been common, increasing the risk of introducing continental pathogens or vectors as illustrated with outbreaks of East Coast fever in 2003 and 2004 in Grande Comore (10). RVFV circulation presented in this study is another example of the exposure of the Republic of Comoros to emerging pathogens and potentially bears major consequences for the local economy and for public health. The improvement of the Comorian veterinary services and the setting up of surveillance programs are essential to limit the risk of introducing devastating diseases in the area.

Rift Valley fever virus (RVFV) is an arthropod-borne phlebovirus reported to be circulating in most parts of Africa. Since 2009, RVFV has been suspected of continuously circulating in the Union of Comoros. To estimate the incidence of RVFV antibody acquisition in the Comorian ruminant population, 191 young goats and cattle were selected in six distinct zones and sampled periodically from April 2010 to August 2011. We found an estimated incidence of RVFV antibody acquisition of 17.5% (95% confidence interval (CI): [8.9-26.1]) with a significant difference between islands (8.2% in Grande Comore, 72.3% in Moheli and 5.8% in Anjouan). Simultaneously, a longitudinal entomological survey was conducted and ruminant trade-related information was collected. No RVFV RNA was detected out of the 1,568 blood-sucking caught insects, including three potential vectors of RVFV mosquito species. Our trade survey suggests that there is a continuous flow of live animals from eastern Africa to the Union of Comoros and movements of ruminants between the three Comoro islands. Finally, a cross-sectional study was performed in August 2011 at the end of the follow-up. We found an estimated RVFV antibody prevalence of 19.3% (95% CI: [15.6%-23.0%]). Our findings suggest a complex RVFV epidemiological cycle in the Union of Comoros with probable inter-islands differences in RVFV circulation patterns. Moheli, and potentially Anjouan, appear to be acting as endemic reservoir of infection whereas RVFV persistence in Grande Comore could be correlated with trade in live animals with the eastern coast of Africa. More data are needed to estimate the real impact of the disease on human health and on the national economy.

Bluetongue virus (BTV) and epizootic haemorrhagic disease virus (EHDV) are members of the Orbivirus genus of the Reoviridae family transmitted between ruminants by the bites of Culicoides midges. BTV went undetected in Reunion Island between its first documented emergence in 1979 and two other serious outbreaks with both BTV-3 and EHDV-6 in 2003, and both EHDV-6 and BTV-2 in 2009. In these outbreaks, infected animals developed symptoms including hyperthermia, anorexia, congestion, prostration and nasal discharge.Samples were collected in 2011 to assess the prevalence of Bland EHD in ruminants native to Reunion Island by serological analysis. A cross-sectional study was undertaken on 67 farms, including a total of 276 cattle, 142 sheep and 71 goats. The prevalence rates of BT and EHD were 58% (95% CI [54.03-62.94]) and 38% (95% CI [33.85-42.63], respectively. Two further suspected outbreaks were confirmed to involve EHDV and BTV/EHDV. A new circulating EHDV serotype 1 of unknown origin was isolated. Our results confirm that the prevalence of both BT and EHD is high and that both are likely currently circulating. A high risk of BTV and EHDV infections was associated with the introdution of ruminants from neighbouring farms without quarantine, the presence of organic and other waste on the farm, and treatment against ectoparasites and insects. (C) 2014 Published by Elsevier B.V.

Abstract. A 58-year-old woman living in Reunion Island and returning from Madagascar was hospitalized for neuroinvasive encephalitis and died 1 month later. West Nile virus (WNV) infection was biologically confirmed by detection of immunoglobulin M (IgM) reactive with WNV antigens in both cerebrospinal fluid and serum, and weak neutralizing activity was also detected. A veterinary survey performed in her traveling area showed a seroprevalence of WNV of 28.7% (95% confidence interval [CI] = 21.1-36.3) in adult poultry, confirming an active circulation of the virus. Development of a severe form could be related to a weak antibody response, because the patient presented low IgM and IgG titers. This case report underlines the constant risk of emergence of West Nile in Indian Ocean territories, including Reunion Island where competent vectors are widely present during the whole year.

Rift Valley fever virus (Phlebovirus, Bunyaviridae) is an arbovirus causing intermittent epizootics and sporadic epidemics primarily in East Africa. Infection causes severe and often fatal illness in young sheep, goats and cattle. Domestic animals and humans can be contaminated by close contact with infectious tissues or through mosquito infectious bites. Rift Valley fever virus was historically restricted to sub-Saharan countries. The probability of Rift Valley fever emerging in virgin areas is likely to be increasing. Its geographical range has extended over the past years. As a recent example, autochthonous cases of Rift Valley fever were recorded in 2007-2008 in Mayotte in the Indian Ocean. It has been proposed that a single infected animal that enters a naive country is sufficient to initiate a major outbreak before Rift Valley fever virus would ever be detected. Unless vaccines are available and widely used to limit its expansion, Rift Valley fever will continue to be a critical issue for human and animal health in the region of the Indian Ocean.

During 2009, pandemic influenza A(H1N1)pdm09 virus affected humans on Réunion Island. Since then, the virus has sustained circulation among local swine herds, raising concerns about the potential for genetic evolution of the virus and possible retransmission back to humans of variants with increased virulence. Continuous surveillance of A(H1N1)pdm09 infection in pigs is recommended.

Introduction : A Madagascar, les premieres epidemies et epizooties de Fievre de la Vallee du Rift (FVR) ont ete rapportees en 1990-1991. A la suite des epidemies et epizooties de FVR en Afrique de l'Est en 2006-2007, la FVR a ete detectee dans les iles du sud ouest de l'Ocean Indien (Union des Comores, Madagascar) en 2007 et 2008. A Madagascar, le premier cas humain a ete detecte en Janvier 2008 suivi de nombreux cas humains et animaux jusqu'en mars 2009. Des etudes retrospectives ont montre que le VFVR avait largement circule dans le pays depuis 2007. Au cours d'une epidemie, des moustiques ont ete collectes autour des cas et des pools de femelles non gorgees composees d'Anopheles coustani, Anopheles squamosus/cydippis et Culex antennatus ont ete trouve infectes par le VFVR, suggerant que ces especes auraient pu jouer un role dans la transmission du virus. Les analyses phylogenetiques des souches ayant circule lors des episodes de 2008-2009 ont montre que le virus etait genetiquement proche de celui ayant circule en 2006-2007 au Kenya suggerant une nouvelle introduction du virus a Madagascar depuis l'Afrique de l'Est. Les mecanismes d'introduction, de maintenance et de diffusion du VFVR a Madagascar restent a elucider. Pour une meilleure comprehension de ces mecanismes, plusieurs etudes ont ete mises en place dans le cadre du programme de cooperation scientifique sur les maladies emergentes dans l'Ocean Indien (OI) : le PCSMAE AnimalRisk avec pour objectifs (i) detecter une circulation a bas-bruit du VFVR, (ii) determiner les especes de moustiques pouvant etre impliquees dans cette circulation a bas-bruit, (iii) determiner si le virus circulant actuellement est genetiquement similaire a celui circulant en 2008-2009 et enfin (iv) identifier des facteurs de risque et les mecanismes associes a cette circulation et a la dissemination de VRFV a Madagascar, (v) etudier les flux de ruminant a l'interieur du pays et entre les iles du sud ouest de l'OI Methodes : Un troupeau sentinelle a ete mis en place dans deux zones agro-ecologiques differentes a Tulear (Sud) et Mampikony (Nord-Ouest). Cent cinquante zebus (60 a Mampikony et 90 a Tulear) âges de 6 mois a 13 mois au debut de l'etude ont ete identifies et preleves mensuellement. Les prelevements de serums ont ete testes pour une recherche en Immunoglobuline (Ig) M et Ig G dirigees contre le VFVR par ELISA sandwich et ELISA indirect respectivement. Des captures entomologiques ont ete organisees dans les sites d'etude en mai et septembre 2010 et mars 2011 pour Tulear ainsi qu'en avril 2010 et avril 2011 a Mampikony. Enfin une etude sur les flux commerciaux de ruminants dans le pays et entre les iles de l'OI a ete menee. Resultats : Durant la periode d'etude 53 animaux ont ete detectes positifs en IgM dirigees contre le VFVR, traduisant une circulation recente du VFVR. Le nombre d'animaux positif en IgM est plus eleve a Tulear qu'a Mampikony (respectivement 38 et 15 animaux). Le pic de nouveaux individus en contact avec le VFVR est situe en janvier 2011. La detection du VFVR par RT-PCR dans les serums recoltes est en cours. Les enquetes menees dans les ports situes au nord et au nord ouest de Madagascar ne nous ont pas permises d'identifier des importations illicites d'animaux vivants ou denrees alimentaires d'origine animale (DAOA) depuis l'Afrique de l'Est ou l'Archipel des Comores. En revanche, nos enquetes nous ont permis de determiner que des exportations de bovins avaient eu lieu depuis le port de Manjunga a destinations des Comores. L'etude sur les flux de bovins dans le pays, nous a permis de determiner et quantifier les flux d'animaux entrant et sortant des marches a zebus d'Ambalavao, Ihosy et Ampanotonkana et les flux entrant a Antananarivo. Au total, 10 849 moustiques dont 5 genres et 31 especes a Mampikony et 5 706 moustiques dont 4 genres et 16 especes a Tulear ont ete identifies. En 2010, les vecteurs potentiels (seules les trois especes citees plus haut sont concernees)

To the Editor: Bluetongue and epizootic hemorrhagic disease are caused by orbiviruses transmitted by Culicoides spp. biting midges (Diptera: Ceratopogonidae). These diseases are restricted to regions where their vectors exist (1) and seem to be expanding to previously unaffected areas (2). Infection of wild and domestic ruminants is common. Bluetongue virus (BTV) causes severe clinical disease in certain breeds of sheep; BTV and epizootic hemorrhagic disease virus (EHDV) cause clinical disease in some species of deer (3,4). Rusa deer (Cervus timorensis rusa), originally from Indonesia, are found in diverse countries in the Pacific region (Papua New Guinea, New Caledonia, New Zealand, and Australia). Introduced to the island of Mauritius in 1639, they are commonly raised in high numbers (≈60,000) for meat production (5). Mauritius is considered free from major livestock diseases; its animal health surveillance is based mainly on clinical monitoring and inspection of carcasses at slaughter. To our knowledge, circulation of orbiviruses in Rusa deer has not been reported in detail in any country where this deer is present. Our study was an initial screening survey of the deer population on the island. A total of 369 deer, representing 28 private farms, were chosen from a list of 42,959 deer. Blood was collected at slaughter, and serum samples were sent to Onderstepoort Veterinary Institute, South Africa, to be tested for antibodies against orbiviruses with a homemade indirect ELISA. To distinguish between BTV and EHDV, samples positive by indirect ELISA were tested for BTV antibodies with the competitive ELISA produced by the Institute for Animal Health (Pirbright, UK). Of the samples positive by competitive ELISA, 3 were tested by serum neutralization against the 24 BTV serotypes (cutoff value >16). Simultaneously, Culicoides spp. midges were trapped in Onderstepoort-type blacklight traps at 3 deer farms in coastal areas (Figure). Trapping was conducted 1 night at each farm, during optimal weather conditions. Midges were kept at room temperature in 95% ethanol until sent to Strasbourg University, France, for identification. Figure Location of farms where Rusa deer were sampled (open circles), herds with orbivirus-seropositive deer (closed circles), biting midge collection sites (triangles), and main cities (crosses) in Mauritius. Most (99%) Culicoides spp. midges were trapped at ... Of the 369 deer serum samples tested, 15 were positive for BTV and 5 for EHDV; seroprevalence was 4.1% for BTV (95% confidence interval 2.0%–6.1%) and 1.3% for EHDV (95% confidence interval 2.0%–6.1%). No significant differences were observed for sex (χ2 = 0.05, p = 0.82). Antibodies (indirect ELISA) against orbiviruses were more prevalent among adults (χ2 = 4.56, p = 0.03). The 3 samples tested by serum neutralization had high titers against BTV-2 (256, 256, and 128) and lower but positive titers against BTV-17 (32 in each), BTV-10 (16 in each), and BTV 21 (32 in 1). Despite reports of clinical signs in other deer species infected with both viruses (3,4), no signs of bluetongue or epizootic hemorrhagic disease were reported for the Rusa deer population in our survey. This absence of clinical disease might be the result of natural resistance of this species to orbiviruses or to the fact that the circulating serotypes are endemic to the area. A total of 13,356 Culicoides spp. midges were obtained; 12% were identified as C. imicola (1,459 females, 138 males) and 88% as C. enderleini (8,800 females, 2,878 males). The former species has been reported in Mauritius (6). In our study, the positive serum came from deer on 4 farms located in the coastal area. This finding could indicate a higher abundance and activity of C. imicola midges in coastal areas, where climate and altitude are more favorable for the vector. Serum neutralization results suggested that at least 4 serotypes could have been circulating in deer from Mauritius. During outbreaks of both viruses in neighboring Reunion Island, several serotypes of BTV were isolated from sheep (7,8) and of EHDV from cattle (9). However, BTV serotypes 17 and 21 have never been isolated from Indian Ocean countries, and serotype 21 has been detected only in Australia (2). Equally, diverse BTV serotypes circulate at different locations on the Indian Ocean and the east coast of Africa (2,5,6). Our results provide serologic indication that EHDV and BTV circulate in Rusa deer in Mauritius. The large population of Rusa deer can represent a potential reservoir host for those viruses and a risk for transmission to other ruminants in Mauritius and neighboring countries. However, Rusa deer could be used as a sentinel population to regularly monitor the circulation of orbiviruses and the introduction of new serotypes to Mauritius. To detect and isolate circulating serotypes and genotypes of these viruses in ruminant species and in potential vectors in Mauritius, further research is needed. In addition, the extent of both viruses and the distribution of Culicoides midges over the island should be investigated in more detail.

To the Editor: Rift Valley fever (RVF) is caused by a Phlebovirus (family Bunyaviridae) transmitted by a wide range of mosquitoes (1). This zoonotic disease is present in Africa, the Middle East, and Madagascar. Infections by RVF virus (RVFV) in ruminants cause massive abortions in livestock and high death rates in young animals, which result in major economic consequences. Humans are infected by mosquito bites, contact, or inhalation of aerosols. RVF is frequently unapparent or mild for humans, inducing an influenza-like illness that occasionally leads to more serious complications such as hemorrhage, meningoencephalitis, retinopathy, or even death (2). Cattle are socially important in Republic of Comoros because massive slaughtering occurs during traditional wedding ceremonies known as “Grands Mariages,” especially on the main island, Grande Comore. Because of low meat production (only 20,000 head of local cattle), a large number of live ruminants enter Grande Comore from Anjouan and Moheli, the other 2 islands of the Republic, from Madagascar and Tanzania without quarantine or any other preliminary veterinary control. We report results from a serosurvey of the ruminant populations on the 3 islands of the Republic of Comoros during the 2009 dry season (April–August). A total of 488 blood samples were collected from randomly selected sheep, goats, and horned cattle and sent to laboratory facilities in Mayotte to be tested by an RVFV immunoglobulin (Ig) G competitive ELISA (3). Fifty IgG RVFV-negative and -positive serum samples were randomly selected for confirmation by a seroneutralization assay using the reference method described in the World Organisation for Animal Health manual (4,5). Of the 488 serum samples tested, 160 were positive for RVFV, for a seroprevalence of 32.8% (95% confidence interval [CI] 28.6%–36.9%). The 3 species were positive for IgG, with prevalence of 30.6% (95% CI 24.2%–37.1%) for cattle, 33.5% (95% CI 27.6%–39.3%) for goats, and 39.0% (95% CI 24.1%–54.0%) for sheep. Using a χ2 test, we found no statistically significant differences regarding species and gender, but more adults than young animals were seropositive for RVFV IgG (p<0.001). Significant differences in RVFV seroprevalence were found between islands (p<0.005), especially between Anjouan (26.6%; 95% CI 20.0%–33.3%) and Moheli (45.8%; 95% CI 31.7%–59.9%); p = 0.011). Of the 50 samples tested in seroneutralization, 31/31 (100%) of RVFV IgG ELISA-positive serum samples were confirmed as positive for RVFV (Table). Table Cross-sectional Rift Valley fever seroprevalence in sheep, goats, and horned cattle, Republic of Comoros, April–August 2009* The serologic evidence of RVFV circulation in the ruminant population of the Republic of Comoros is in accordance with the epidemiologic situation described in other countries in the area. Actually, the serosurvey was implemented after the RVF outbreaks reported in several countries in eastern Africa in 2007 during El Nino rains (6). In August 2007, RVFV was detected in a young person from Comoros, and indigenous transmission of RVFV in Mayotte was confirmed in 2008 (7). RVF outbreaks were also reported in Madagascar during the 2008 and 2009 rainy seasons (January–May 2008 and November–March 2009) (8). To our knowledge, no circulation of RVFV in Republic of Comoros has been reported despite frequent legal and illegal movements of populations and goods between Republic of Comoros and eastern Africa, Mayotte, Madagascar, and the others islands of the area. With 1 of 3 ruminants having been in contact with RVFV, our results suggest that the human population in these islands have likely been widely exposed to this virus. However, several questions remain unanswered: Was RVFV recently introduced in the country? Has the virus settled down in a local reservoir for years without major clinical consequences before reemerging thanks to favorable conditions? Actually, no massive abortions in livestock or high death rate in young animals have been notified so far by the Comorian Sanitary Services. Therefore, the origin of infection is presently unknown because animals could have been infected on the island or in another country from where they have been imported. Because live ruminants have been imported from neighboring countries for 20 years, the risk of introducing new diseases in the country is high. Despite efforts of the Comorian sanitary services, the Republic of Comoros is particularly vulnerable to pathogens intrusion. Blackleg (1970, 1995) and the contagious ecthyma (1999) were probably introduced into the country by live ruminants imported from Madagascar (9). Since 2002, importation of live animals from Tanzania has been common, increasing the risk of introducing continental pathogens or vectors as illustrated with outbreaks of East Coast fever in 2003 and 2004 in Grande Comore (10). RVFV circulation presented in this study is another example of the exposure of the Republic of Comoros to emerging pathogens and potentially bears major consequences for the local economy and for public health. The improvement of the Comorian veterinary services and the setting up of surveillance programs are essential to limit the risk of introducing devastating diseases in the area.

BACKGROUND:The genus Varicellovirus (family Herpesviridae subfamily Alphaherpesvirinae) includes a group of viruses genetically and antigenically related to bovine herpesvirus 1 (BoHV-1) among which cervid herpesvirus 2 (CvHV-2) can be of importance in reindeer. These viruses are known to be responsible for different diseases in both wild and domestic animals. Reindeer are a keystone in the indigenous Saami culture and previous studies have reported the presence of antibodies against alphaherpesviruses in semi-domesticated reindeer in northern Norway. Mortality rates, especially in calves, can be very high in some herds and the abortion potential of alphaherpesvirus in reindeer, unlike in bovines, remains unknown. ELISA kits are the most used screening method in domestic ruminants and given the close genetic relationship between viruses within this genus, it might be possible to use such kits to screen cervids for different alphaherpesviruses. We have compared three different commercial ELISA kits in order to validate its use for reindeer and CvHV-2.METHODS:Three commercial bovine ELISA kits (A, B and C), using either indirect (A) or blocking (B and C) ELISA techniques to detect antibodies against BoHV-1 were tested with sera from 154 reindeer in order to detect antibodies against CvHV-2. A Spearman's rank-based coefficient of correlation (rho) was calculated. A dilution trial was performed for all kits. A virus neutralization test using both BoHV-1 and CvHV-2 was carried out.RESULTS:Seroprevalence was almost the same with all kits (40-41%). Despite a similar qualitative score, quantitatively kits classified samples differently and a strong correlation was only identified between Kits B and C. Blocking kits performed better in both repeatability and in the dilution trial. The virus neutralization results confirmed the ELISA results to a very high degree. Neutralizing titres ranged from 1:2 to 1:256 and from 0 to 1:16 against CvHV-2 and BoHV-1 respectively.CONCLUSION:Results show that the genetic and antigenic similarity between BoHV-1 and CvHV-2 enables the use of a bovine gB blocking ELISA kit to screen reindeer. The use of an ELISA kit is both cheaper and time saving, allowing screening of large populations. This study revealed a high number of positive animals against CvHV-2 and its impact and distribution in the general population should be further evaluated.