El-Rhman Mariam M Abd, Abo El-Hassan Diea G, Awad Walid S, Salem Sayed A H
Department of Preventive Medicine, General Organization for Veterinary Services, Dokki, Giza, Egypt.
Department of Internal Medicine and Infectious Diseases, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt.
Vet World. 2020 Jan;13(1):1-9. doi: 10.14202/vetworld.2020.1-9. Epub 2020 Jan 3.
The present study was aimed to investigate the epidemic situation of foot-and-mouth disease (FMD) in Egypt from 2016 to 2018 based on the detection of FMD virus (FMDV) in carrier or previously infected animals, by determination of antibodies against non-structural protein (NSP), implementation a pilot study on circulating FMDV serotypes and assure the efficacy of locally produced inactivated trivalent vaccine.
A total of 1500 sera were collected from apparent healthy vaccinated cattle and buffaloes from three Egyptian geographical sectors, representing ten governorates. Determination of FMD antibodies against NSP was carried out using 3ABC enzyme-linked immunosorbent assay (ELISA) test. Serotyping of the circulating FMDV and assure the vaccine efficacy was performed using solid-phase competitive ELISA.
The 3ABC ELISA test revealed 26.4% and 23.7% positive for FMDV-NSP antibodies in cattle and buffalo sera, respectively. The highest positivity was in Delta Sector among both cattle 42.3% and buffaloes 28.8%. Serotyping of FMDV-positive NSP sera in El-Qalyubia Governorate for the circulating FMDV serotypes O, A, and Southern African Territories (SAT) 2 was 52.2%, 17.4%, and 30.4% in cattle and 31.8%, 27.3%, and 40.9% in buffaloes, respectively. The overall protection level due to the vaccination program was 62.1 and 60.9% in cattle and buffaloes, respectively, while the protective level of the FMDV serotypes O, A, and SAT2 included in the inactivated trivalent vaccine was 73.9, 84.6, and 63.8% in cattle and 72.3, 82.3, and 63.5% in buffaloes, respectively.
The present study recommended full determination for the immunogenic relationship between the vaccine strains and the field strains to attain maximum protection against the circulating viruses.
本研究旨在基于对携带或曾感染口蹄疫病毒（FMDV）的动物进行检测，通过测定抗非结构蛋白（NSP）抗体，对流经的FMDV血清型开展初步研究，并确保本地生产的三价灭活疫苗的效力，调查2016年至2018年埃及口蹄疫（FMD）的流行情况。
从埃及三个地理区域（代表十个省份）表面健康且已接种疫苗的牛和水牛中总共采集了1500份血清。使用3ABC酶联免疫吸附测定（ELISA）试验测定抗NSP的FMD抗体。使用固相竞争ELISA对流经的FMDV进行血清分型并确保疫苗效力。
3ABC ELISA试验显示，牛血清和水牛血清中FMDV-NSP抗体阳性率分别为26.4%和23.7%。牛和水牛中阳性率最高的是三角洲地区，分别为42.3%和28.8%。在盖勒尤比省，FMDV阳性NSP血清中，牛的O型、A型和南非地区（SAT）2型FMDV血清型分别为52.2%、17.4%和30.4%，水牛分别为31.8%、27.3%和40.9%。由于疫苗接种计划，牛和水牛的总体保护水平分别为62.1%和60.9%，而三价灭活疫苗中包含的O型、A型和SAT2型FMDV血清型的保护水平，牛分别为73.9%、84.6%和63.8%，水牛分别为72.3%、82.3%和63.5%。
本研究建议全面确定疫苗株与田间毒株之间的免疫原性关系，以实现对流行病毒的最大程度保护。
