42.International Symposium on Diseases of Zoo and Wild Animals, Prague, Czech Republic,

May 04-08-2005

AN OUTBREAK OF Mycoplasma capricolum subsp. Capripneumoniae (MCCP) in nondomestic hoofstock

SCHULZ J¹, ARIF A¹, THIAUCOURT F², HAMMER S¹

¹Al Wabra Wildlife Preservation, PO Box 44069, Doha, State of Qatar; awwp.vet@alwabra.com

²CIRAD-EMVT-SA, Ta 30/G, Campus international de Baillarguet, 34398 Montpellier cedex 05, France

Extended Abstract

Summary

Contagious caprine pleuropneumonia (CCPP) is an acute highly contagious disease of goats caused by Mycoplasma capricolum subsp. capripneumoniae (Mccp). It is characterized by fever, coughing, severe respiratory distress, and a high mortality. The principal lesion at necropsy is a fibrinous pleuropneumonia. At Al Wabra Wildlife Preservation in Qatar, an outbreak of CCPP in Wild Goats (Carpa aegagrus), Nubian Ibex (Capra ibex), Laristan Mufflon (Ovis gmelini laristanica) and Gerenuk (Lithocranius walleri) was diagnosed by PCR and isolation of Mccp. To our knowledge, this is the first time that this disease was identified in nondomestic hoofstock. So far, only antibody titers of Mccp have been found in some wild herbivores and camels. Investigations have shown that CCPP might become enzootic in the Middle East. This is mainly due to the survival of unapparent chronic carriers that transmit the disease. The presented findings indicate that CCPP should be considered as a potential threat for wildlife.

Introduction

CCPP is a significant disease of goats in Africa, Western Asia and the Middle East (JONES and WOOD, 1988), and is characterized primarily by its acute, highly contagious nature, fever, coughing and severe respiratory symptoms. The incubation period varies between 6 days and 4 weeks. It starts with high fever then painful respiratory signs become apparent. Unlike other mycoplasma infections, “true CCPP” does not induce prominent lesions in organs other than the thoracic cavity. The disease causes interstitial, fibrinous pleuropneumonia, interlobular edema and hepatization (Kaliner and MacOwan, 1976) of the lung, accompanied by pleurisy with accumulation of straw-colored fluids. The mortality rate is up to 80%. CCPP is transmitted by direct contact through inhalation of infective aerosols. The causative agent of contagious caprine pleuropneumonia (CCPP) is Mycoplasma capricolum subsp. capripneumoniae (Mccp), which was previously known by the strain name F38 (Leach et al., 1993). Mccp is related to M. mycoides capri (type strain PG-3), which was for many years considered to be the causative agent of CCPP, because it was the agent most commonly isolated from goats (McMARTIN et al., 1980). In 1976, however, MACOWAN and MINETTE (1976) demonstrated a new mycoplasma strain (designated F-38) from a CCPP outbreak in Kenya to be the real cause of CCPP. Diagnosis must be confirmed by PCR technique or isolation of Mccp, which can be identified by immunofluorescence or metabolic inhibition tests. Several serological tests (ELISA, CF, PH) can be performed for the detection of antibodies. Clinically, CCPP may be confused with other pneumonic conditions such as pasteurellosis, other mycoplasma infections (Thiaucourt and Bolske, 1996) and peste des petits ruminants. To our knowledge, Mccp has never been described to cause disease in sheep, cattle or nondomestic hoofstock. Only antibody titers of Mccp have been found in some wild herbivores and camels (PALING et al., 1978).

Case Report

Al Wabra Wildlife Preservation (AWWP) in Qatar keeps more than 1500 individuals of 25 different nondomestic hoofstock species in pure breeding groups. In March and April 2004 an outbreak of a non identified disease affected mainly Wild Goats (Carpa aegagrus) and Nubian Ibex (Capra ibex). Within 6 weeks 20 Wild Goats (83% of the population) and 11 Nubian Ibex (58%) died. Additional, in May and June 2004 four Laristan Mufflon (Ovis gmelini laristanica) and one old Gerenuk (Lithocranius walleri) also deceased with similar symptoms. Concerning the family Capri, all animals had hepatized lungs, fibrinous pleuropneumonia, and straw-like fluids in the pleural cavity and sometimes also in the pericard. The similarities in the necropsy findings and the high number of dead animals in a short time, indicated very quick that an outbreak of a severe infectious disease was most probably. Considering the primarily involved species, the clinical signs and the macroscopic post mortem findings, which only affected the respiratory tract of the animals, CCPP was suspected.

In the beginning of the outbreak, animals with respiratory symptoms were treated with long-acting antibiotics without any success. In correspondence with the suggestive diagnosis of CCPP, a “CCPP-vaccine” manufactured in Turkey was found in Qatar which was used immediately trying to save the remaining animals but it didn’t seem to have any effect. Finally a CCPP vaccine manufactured in Kenya and made with Mccp antigen (Caprivax®, Kenya Veterinary Vaccines Production Institute, P.O. Box 53260, Nairobi, Kenya) was imported and used. Since then, no further animal has died with typical CCPP-findings.

Discussion

Histological samples verified a fibrinopurulent pleuropneumonia, suggestive for pasteurellosis or a mycoplasma infection. After some unsuccessful attempts of different laboratories, CIRAD in France (OIE-reference laboratory) was eventually able to culture a mycoplasma strain that was identified as Mccp by PCR (WOUBIT et al., 2004) and dot blotting with a specific monoclonal antibody. A 2400 bp long DNA fragment from this strain was amplified and sequenced (Lorenzon et al., 2002). The sequence was identical to the one obtained from a Mccp strain from East Africa (Genbank AF378154).

To the authors knowledge it is the first time that this disease could be identified in wildlife. Up to now the disease was supposed to be confined to domestic goats. Therefore this new finding is very important as it indicates that CCPP should be considered as a potential threat not only for wildlife in captivity, but also in their natural habitat.

There have been two major problems to control the disease outbreak at AWWP: First of all, it took a long time to find a laboratory which was able to isolate Mccp. Even though CCPP was suspected quickly, the confirmation took almost 2 months as the bacterium is easily overgrown by other pathogens during transport and it only develops slowly and in special media. The second big problem was to find the appropriate vaccine. The one available in Qatar didn’t induce any protection and this could be explained by the fact that it is not made with the proper mycoplasma strain even though it was labeled “CCPP vaccine”. It contains M. mycoides subsp. capri which is not in compliance with the OIE manual of standards for vaccine production (Rurangirwa and KINYILI, 2004). Up to now, the only CCPP vaccine producer is in Kenya and the vaccine contains lyophilised Mccp suspended in saponin. The optimal dose of 0.15 mg of mycoplasma provides protection for over 1 year (Rurangirwa et al., 1987). This vaccine has shown in field tests to confer 100 percent protection to contact exposure (RURANGIRWA et al., 1991). It needs great care to use this vaccine in wildlife, because it is not registered for wildlife. In the authors experience some individuals showed up with weakness for two days after vaccination with swellings at the injection site whereas others did not present any side effects after the vaccination at all. However different species/individuals may react differently to the vaccine. In AWWP a CCPP-vaccination-program has been set up with a booster four weeks after initial vaccination and then revaccination on a yearly basis.

Although the most important step for the control of CCPP is vaccination, surveillance by serology might be helpful to detect the CCPP reservoir animals too. Currently further investigations on AWWP are in process to find the origin of the outbreak, as there has been no direct contact to domestic goats.

Serologic testing of susceptible animals for import- or exportation is a recommended safeguard, but even in negative animals it should be considered that some animals may not display a sero-conversion even though they do carry mycoplasma. Some nondomestic hoofstock may not be susceptible to CCPP but serve as a reservoir. Investigations have shown that CCPP might become enzootic in the Middle East (JONES and WOOD, 1988). This is mainly due to the persistence of unapparent chronic carriers that transmit the disease. As a consequence, this would require that susceptible species that are imported to the Middle East should be vaccinated during the quarantine period.

Antibiotic treatment of affected animals at AWWP has been implemented in urgency in order to possibly save valuable animals. However it may not be advisable to use antibiotic treatment routinely as successful treated animals may be chronic carriers of Mccp and therefore a permanent risk for the collection.

References

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