Serological Epidemiology of Foot-and-mouth Disease among Sedentary Mixed-species Herds in Adamawa Region, Cameroon
Silas Lendzele Sevidzem *
Ecole Doctorale des Grandes Ecoles (EDGE), Laboratoire d’Ecologie Vectorielle (LEV-IRET), BP: 13354, Libreville, Gabon.
Abdoulmoumini Mamoudou
Department of Parasitology and Parasitological Diseases, School of Veterinary Medicine and Sciences, University of Ngaoundere, P.O.Box 455, Ngaoundere, Cameroon.
Jacques François Mavoungou
Institut de Recherche en Ecologie Tropicale (IRET-CENAREST), BP: 13354, Libreville, Gabon and University of Science and Technology of Masuku (USTM), Franceville, Gabon.
Ikoum Dalida
Department of Parasitology and Parasitological Diseases, School of Veterinary Medicine and Sciences, University of Ngaoundere, P.O.Box 455, Ngaoundere, Cameroon.
Mohammadou Bouba
Department of Parasitology and Parasitological Diseases, School of Veterinary Medicine and Sciences, University of Ngaoundere, P.O.Box 455, Ngaoundere, Cameroon.
Oumarou Lebale
Department of Parasitology and Parasitological Diseases, School of Veterinary Medicine and Sciences, University of Ngaoundere, P.O.Box 455, Ngaoundere, Cameroon.
Hiol Victor Dermy
Department of Parasitology and Parasitological Diseases, School of Veterinary Medicine and Sciences, University of Ngaoundere, P.O.Box 455, Ngaoundere, Cameroon.
Rodrigue Mintsa Nguema
Institut de Recherche en Ecologie Tropicale (IRET-CENAREST), BP: 13354, Libreville, Gabon.
Zinga-Koumba Christophe Roland
Institut de Recherche en Ecologie Tropicale (IRET-CENAREST), BP: 13354, Libreville, Gabon.
Acapovi-Yao Genevieve Lydie
Université Félix Houphouët - Boigny, UFR Biosciences 22, BP: 582, Abidjan 22, Côte d’Ivoire.
Simon Dickmu
Laboratoire National Vétérinaire-LANAVET, Garoua, Cameroon.
Garabed Rebecca
Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, OH, USA.
*Author to whom correspondence should be addressed.
Abstract
Foot-and-mouth disease (FMD) is an economically important viral disease of domestic animals and wildlife. High circulation occurs during outbreaks but little is known about the current transmission dynamics in sedentary cattle and sheep herds. To investigate on this, samples from cattle and sheep located in the Vina Division of the Adamawa region of Cameroon, during FMD outbreaks were collected. Non-Structural Protein (NSP) and antigen detecting/serotyping FMD ELISAs were used for sample screening. The NSP serological data of cattle was used to estimate transmission parameters in catalytic and reverse catalytic models. The Akaike’s Information Criteria (AIC) revealed the reverse catalytic model as the most parsimonious for the NSP serological data and was used to estimate the force of infection (FOI), the rate of waning immunity and to estimate historic periods of sustained transmission. Four serological types of FMD notably O, A, SAT 1 and SAT 2 were identified from cattle vesicular epithelia tissues. Seroprevalence findings revealed 65.14% and 15.71% FMDV antibodies in cattle and sheep respectively with highest prevalence in both populations occurring in Mbidjoro. The FOI (λ) in sedentary herds was constant; the rate of waning immunity (ω) was 0.32 meaning cattle are generally immune for 3.12 years post natural infection. The reproductive number (Rt) was 7.33, meaning approximately 87% of cattle always need to be effectively immunized to prevent outbreaks. Therefore, FMD circulates in sedentary cattle and sheep populations in the study area with four serological types detected in cattle.
Keywords: Seroprevalence, serotypes, Foot-and-mouth disease, reverse catalytic model, cattle, sheep