Effect of vaccination on cattle subclinically infected with foot-and-mouth disease virus in Cameroon
Effect of vaccination on cattle subclinically infected with foot-and-mouth disease virus in Cameroon
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DOI：
10.1016/j.prevetmed.2018.04.003
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发表时间：
2018-07-01
影响因子：
2.6
通讯作者：
Arzt, Jonathan
中科院分区：
文献类型：
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作者：
Bertram, Miranda R.;Delgado, Amy;Arzt, Jonathan
口蹄疫（Foot-and-mouth disease，FMD）是世界范围内传染性最强、经济上最重要的家畜疾病之一。四种血清型口蹄疫病毒（FMDV; O，A，SAT 1，SAT 2）在喀麦隆流行，最近在2014年推出了针对三种最常见血清型（0，A，SAT 2）的三价灭活疫苗。本研究的目的是表征喀麦隆阿达马瓦地区自然高流行条件下牛的疫苗性能。在12个月期间，通过采集血清和口咽液（OPF）样本监测接种牛（n = 50）和未接种对照牛（n = 100）。抗FMDV非结构蛋白（抗NSP）血清阳性率从研究开始时的59.3%（89/150）增加到研究结束时的85.8%（103/120），尽管仅在6只未接种疫苗的动物中检测到FMD的临床体征，但在28%（42/150）的动物中发现了FMDV RNA。病毒序列分析表明，在研究期间，研究牛群中存在FMDV血清型O和A的亚临床感染，这反映在研究期间抗NSP血清阳性率的总体增加。在OPF中，疫苗接种状态与血清转换或FMDV RNA流行率之间没有关联。较年轻的牛在OPF中检测到FMDV RNA的几率较高，但较年长的动物更可能是血清阳性。这项研究表明，对先前暴露于FMDV的畜群进行疫苗接种可能有助于限制FMDV的临床症状，减少FMDV造成的经济损失。这些发现也表明，亚临床流行的口蹄疫病毒发生在高流行地区，无论疫苗接种。
Foot-and-mouth disease (FMD) is one of the most contagious and economically important livestock diseases worldwide. Four serotypes of FMD virus (FMDV; O, A, SAT1, SAT2) circulate in Cameroon, and a trivalent inactivated vaccine against the three most common serotypes (0, A, SAT2) was recently introduced in 2014. The objective of this study was to characterize vaccine performance in cattle under natural hyperendemic conditions in the Adamawa region of Cameroon. Vaccinated cattle (n = 50) and non-vaccinated controls (n = 100) were monitored by serum and oropharyngeal fluid (OPF) sample collection through a 12-month period. Anti-FMDV non-structural protein (anti-NSP) seroprevalence increased from 59.3% (89/150) at the beginning of the study to 85.8% (103/120) at the end of the study, and FMDV RNA was found in 28% (42/150) of animals overall, despite detection of clinical signs of FMD in only 6 non-vaccinated animals. Viral sequence analysis indicated that subclinical infections of FMDV serotypes O and A were present within the study herds during the study period, which was reflected by an overall increase of anti-NSP seroprevalence during the study. There was no association between vaccination status and seroconversion or prevalence of FMDV RNA in OPF. Younger cattle had higher odds of detection of FMDV RNA in OPF, but older animals were more likely to be seropositive. This study suggests vaccination of herds previously exposed to FMDV may help to limit clinical signs and reduce economic losses caused by FMDV. These findings also suggest that subclinical circulation of FMDV occurs in hyperendemic regions regardless of vaccination.