![]() 14– 17 However, the situation today is still not fully satisfactory and CA remains a significant burden in countries where small ruminant dairy production is important. ![]() These difficulties have prompted a huge field of research and development for diagnosis and control tools over the past years. As clinical signs are non-specific, a CA outbreak cannot be confirmed without laboratory testing. 7– 10 Furthermore, mixed mycoplasmal infections in goats are regularly reported, 11– 13 which could complicate diagnosis and control measures. 6– 8 They share many genetic and antigenic traits making it more complicated to specifically segregate and identify them. 5 These three (sub)species are phylogenetically distant from Ma and belong or are close to a phylogenetically homogeneous group named the M. putrefaciens ( Mp), are considered equally causative agents in goats, as their infection results in a similar clinical picture (Conclusion of the EC COST action 826). Ma is still the main etiological agent in sheep, while three other (sub)species, namely M. 4 At that time, although the Mycoplasma genus was not yet established, this type of bacteria was already known to be parasitic and to cause chronic and generally difficult-to-eradicate diseases. Mycoplasma ( M.) agalactiae (Ma), the “historical” etiological agent, was successfully isolated for the first time in 1923 and characterized as “filterable but not invisible”, similarly to the agent of bovine pleuropneumonia. It should be considered a serious threat to animal welfare in its acute phase as well as in its chronic form. ![]() 3 It primarily results in a drop in milk production, followed by an increased general morbidity and mortality. CA has multiple clinical signs that are often gathered under the acronym MAKePS, for mastitis, arthritis, keratoconjunctivitis, pneumonia, and septicemia. 2 Despite being termed “agalactia”, which refers to a marked drop or even a complete loss of milk production, its clinical outcome is not restricted to lactating females nor to only the udder/mammary glands. 1 Its contagious nature resulted in the official designation of the name CA in 1871 by Brusasco. Known for more than 200 years, contagious agalactia (CA) of sheep and goats was first reported back in 1816 in Italy, where it was quickly dubbed “mal di sito” (“disease of the place”) in reference to its ability to persist in an environment and contaminate newly introduced herds. Keywords: contagious agalactia, mycoplasma, disease prevention and control, diagnosis, pathogenicity and infection course, epidemiology Discussion also underlines the detrimental effect of contagious agalactia on small ruminant welfare. Here we review all these aspects in order to highlight recent progress made and identify gaps in knowledge or tools needed for better disease management. The existence of asymptomatic carriers and the numerous sources of infections contribute to rapid spread of the disease and complicate the control and prevention efforts. The persistence of the etiological agents, despite their overall susceptibility to antimicrobials, comes from their genetic plasticity and capacity to escape the host immune response. It requires long-term commitment but is often unsuccessful, with frequent clinical relapses. CA control relies on vaccines, chemotherapy and good herd management practices. However, as current diagnostic tests are expensive and difficult to implement, it is certainly underdiagnosed and prevalence data are only available for a few countries. CA has been reported worldwide and its geographic distribution maps to that of small ruminant breeding areas. Clinical signs are multiple, including mastitis, arthritis, keratoconjunctivitis, pneumonia, and septicemia, non-specific, and expressed differently depending whether sheep or goats are affected, on causative mycoplasmas as well as type of husbandry. Université de Lyon, ANSES, Laboratoire de Lyon, VetAgro Sup, UMR Mycoplasmoses des Ruminants, Lyon 69364, FranceĪNSES Laboratoire de Lyon, UMR Mycoplasmoses des Ruminants, 31 Avenue Tony Garnier Lyon Cedex 07 69364, FranceĪbstract: Contagious agalactia (CA) is a disease caused equally by four Mycoplasma species, in single or mixed infections.
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