Crimean-Congo Hemorrhagic Fever Virus Antibodies among Livestock on Corsica, France, 2014-2016.

We conducted a serologic survey for Crimean-Congo hemorrhagic fever virus antibodies in livestock (cattle, sheep, and goats; N = 3,890) on Corsica (island of France) during 2014-2016. Overall, 9.1% of animals were seropositive, suggesting this virus circulates on Corsica. However, virus identification is needed to confirm these results.

An international collaborative study to determine the prevalence of contagious caprine pleuropneumonia by monoclonal antibody-based cELISA.

BACKGROUND: Few serological tests are available for detecting antibodies against Mycoplasma capricolum subsp. capripneumoniae, the causal agent of contagious caprine pleuropneumonia (CCPP). The complement fixation test, the test prescribed for international trade purposes, uses a crude antigen that cross-reacts with all the other mycoplasma species of the "mycoides cluster" frequently infecting goat herds. The lack of a more specific test has been a real obstacle to the evaluation of the prevalence and economic impact of CCPP worldwide. A new competitive ELISA kit for CCPP, based on a previous blocking ELISA, was formatted at CIRAD and used to evaluate the prevalence of CCPP in some regions of Kenya, Ethiopia, Mauritius, Tajikistan and Pakistan in an international collaborative study. RESULTS: The strict specificity of the test was confirmed in CCPP-free goat herds exposed to other mycoplasma species of the "mycoides cluster". Prevalence studies were performed across the enzootic range of the disease in Africa and Asia. Seroprevalence was estimated at 14.6% in the Afar region of Ethiopia, whereas all the herds presented for CCPP vaccination in Kenya tested positive (individual seroprevalence varied from 6 to 90% within each herd). In Mauritius, where CCPP emerged in 2009, nine of 62 herds tested positive. In Central Asia, where the disease was confirmed only recently, no positive animals were detected in the Wakhan District of Afghanistan or across the border in neighboring areas of Tajikistan, whereas seroprevalence varied between 2.7% and 44.2% in the other districts investigated and in northern Pakistan. The test was also used to monitor seroconversion in vaccinated animals. CONCLUSIONS: This newly formatted CCPP cELISA kit has retained the high specificity of the original kit. It can therefore be used to evaluate the prevalence of CCPP in countries or regions without vaccination programs. It could also be used to monitor the efficacy of vaccination campaigns as high-quality vaccines induce high rates of seroconversion.

Unexpected field observations and transmission dynamics of contagious caprine pleuropneumonia in a sand gazelle herd.

Contagious caprine pleuropneumonia (CCPP), caused by Mycoplasma capricolum subsp. capripneumoniae, has long been considered a goat-specific disease. Since 2007 there has been growing evidence that this disease can affect wild ungulates either kept in captivity or in the wild. In 2013, a large collection of sand gazelles (Gazella marica) held in the United Arab Emirates suffered heavy losses due to a CCPP epizootic confirmed by PCR and isolation. Animals displayed typical lesions, with unilateral pneumonia and profuse pleurisy. An initial antibiotic treatment consisting of tylosin administered in drinking water did not improve the animals' condition and vaccination failed to stop the spread to contiguous pens. A treatment with tetracycline mixed in feed pellets finally succeeded to stop the evolution of the disease. A subsequent vaccine trial, performed on naïve animals, showed that only a reference CCPP vaccine produced according to OIE standards induced a sero-conversion by CCPP competition ELISA, while the commercially available vaccines did not. A SEIRD compartment transmission model was developed to better understand the dynamics of the disease. The parameters were initially set as per expert opinion and then adjusted to fit the observed mortality data. The basic reproductive number R0 was estimated to be between 2.3-2.7, while the final mortality rate reached up to 70% in some pens. Transmission of infectious droplets from an external source, through a distance of at least the 50 m separating the pens from the perimeter fence, remains the most plausible explanation for the contamination of this stock of gazelles.

Within-herd spread of contagious bovine pleuropneumonia in Ethiopian highlands.

Contagious bovine pleuropneumonia (CBPP) is a major threat for cattle health and production in Africa. This disease is caused by the small-colony type of Mycoplasma mycoides subspecies mycoides (MmmSC). Transmission occurs from direct and repeated contacts between sick and healthy animals. Veterinary services recently reported a resurgence of CBPP in the province of West Wellega, in the Ethiopian highlands. A research program was set up to estimate the epidemiological parameters of the within-herd infection spread. A follow-up survey was implemented in 71 sampled herds of the Boji district (West Wellega province). Fifteen herds were classified as newly infected and used in a serological- and clinical-incidence study. The overall 16-month cumulative sero-incidence risk was 34%. Clinical cases were recorded for 39% of the seropositive cattle; case-fatality risk was 13%. There was no evidence of benefit on infection spread of CBPP-control measures used locally by farmers (isolation or antibiotic treatments of sick animals). This might be related to a lack of power in the statistical analyses or to a quality problem for the medications used (and more generally, for health-care delivery in the Boji district).