Dual infections of feeder pigs with porcine reproductive and respiratory syndrome virus followed by porcine respiratory coronavirus or swine influenza virus: A clinical and virological study
Dual infections of feeder pigs with porcine reproductive and respiratory syndrome virus followed by porcine respiratory coronavirus or swine influenza virus: A clinical and virological study
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DOI：
10.1016/0378-1135(95)00145-x
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发表时间：
1996-02-01
影响因子：
3.3
通讯作者：
Pensaert, M
中科院分区：
文献类型：
--
作者：
VanReeth, K;Nauwynck, H;Pensaert, M
研究了猪繁殖与呼吸综合征病毒（PRRSV）和第二种常见呼吸道病毒（猪呼吸道冠状病毒（PRCV）或猪流感病毒（SIV））的双重感染。目的是确定双重感染与单一病毒感染相比是否会导致临床表现增强。还检查了PRRSV复制是否影响呼吸道中PRCV或SIV的复制。将常规的10周龄猪的组用仅PRRSV（3只猪）、仅PRCV（4只猪）或仅SIV（4只猪）接种。以3天的间隔进行PRRSV-PRCV（4头猪）和PRRSV-SIV（3组，每组3头、4头和5头猪）的双重接种。包括一组未接种的对照猪（8头猪）。仅PRRSV感染在2 DPI时诱导一过性发热（40.2 ℃），但无呼吸体征。仅PRCV感染仍处于亚临床状态。仅SIV感染导致1天发热（40.1 ℃）伴中度呼吸急促和呼吸困难。PRRSV-PRCV感染引起持续9天的发热（峰值40.9 ℃），伴有呼吸急促、呼吸困难和排痰性咳嗽。PRRSV-SIV感染在所有3组中均导致发热和呼吸道体征。然而，第1组的临床体征比第2组和第3组更明显。第1组猪在10天内出现发热（峰值41.4 ℃）、呼吸急促、腹式呼吸明显呼吸困难和排痰性咳嗽。第2组和第3组的猪分别发热5天和3天（峰值40.6和40.3 ℃），并出现轻度呼吸系统疾病。在第二病毒的14 DPI期间，PRRSV-PRCV组的平均体重增加为5.9 kg，PRRSV-SIV组1、2和3分别为4.0、6.8和6.7 kg。在相应期间，仅PRRSV组的平均体重增加为8.6 kg。结果表明，病毒双重感染比病毒单一感染引起的疾病和生长迟缓更严重，PRCV排泄曲线在病毒单一感染组和双重感染组中相似。在双重接种猪中，SIV的排泄延迟2天。因此，第二病毒的复制不受（PRCV）或仅受轻微（SIV）的先前感染PRRSV的影响。
Dual infections of pigs with porcine reproductive and respiratory syndrome virus (PRRSV) followed by a second common respiratory virus, either porcine respiratory coronavirus (PRCV) or swine influenza virus (SIV), were studied. The aim was to determine if dual infections, as compared to single virus infections, result in enhanced clinical manifestations. It was also examined if PRRSV replication affects replication of PRCV or SIV in the respiratory tract. Groups of conventional 10 week old pigs were inoculated with PRRSV-only (3 pigs), PRCV-only (4 pigs) or SIV-only (4 pigs). Dual inoculations with PRRSV-PRCV (4 pigs) and PRRSV-SIV (3 groups of 3, 4 and 5 pigs) were performed at a 3 day interval. A group of uninoculated control pigs (8 pigs) was included. The infection with PRRSV-only induced a transient fever (40.2 degrees C) at 2 DPI, but no respiratory signs. The PRCV-only infection remained subclinical. The SIV-only infection resulted in a one day fever (40.1 degrees C) with moderate tachypnoea and dyspnoea. Mean weight gain in the virus-inoculated groups was retarded compared with the control group.The PRRSV-PRCV infection induced a 9 day lasting fever (peak 40.9 degrees C) with tachypnoea, dyspnoea and productive coughing. The PRRSV-SIV infection resulted in fever and respiratory signs in all 3 groups. Clinical signs, however, were more pronounced in group 1 than in groups 2 and 3. Pigs of group 1 showed fever during 10 days (peak 41.4 degrees C), tachypnoea, marked dyspnoea with abdominal breathing, and a productive cough. Pigs of groups 2 and 3 had fever for 5 and 3 days (peaks 40.6 and 40.3 degrees C) respectively and mild respiratory disorders. Mean weight gain during 14 DPI of the 2nd virus was 5.9 kg in the PRRSV-PRCV group and 4.0, 6.8 and 6.7 ki: in PRRSV-SIV groups 1, 2 and 3 respectively. Mean weight gain during the corresponding period in the PRRSV-only group was 8.6 kg. It was concluded that dual infections with viruses causes more severe disease and growth retardation than single PRRSV infection.PRCV excretion curves were similar in single and dual virus inoculated groups. Excretion of SIV was delayed by 2 days in the dual inoculated pigs. Thus, replication of the second virus is not (PRCV) or only slightly (SIV) affected by a prior infection with PRRSV.