Dittmer K E, Hinkson J A, Dwyer C, Adlington B, van Andel M
a Institute of Veterinary, Animal and Biomedical Sciences , Massey University , Private Bag 11 222, Palmerston North 4442 , New Zealand.
b Ministry for Primary Industries , Wallaceville, Upper Hutt 5018 , New Zealand.
N Z Vet J. 2018 Jan;66(1):9-15. doi: 10.1080/00480169.2017.1369912. Epub 2017 Aug 31.
To determine the prevalence of infection with Candidatus Mycoplasma haemolamae (Mhl), antibodies to bovine viral diarrhoea virus (BVDV), and BVDV antigen, and the prevalence of animals with elevated faecal nematode egg counts (FEC) in a sample of adult New Zealand alpaca (Vicugna pacos).
Blood samples were obtained from 175 alpaca, collected from 15 farms around New Zealand, and from 31 samples sent to a diagnostic laboratory for routine haematology. Blood smears (n=170) were examined microscopically for the presence of haemoplasma, and DNA was extracted from whole blood (n=206) for real-time PCR testing for Mhl. Packed cell volume (PCV) was determined for 193 samples. Serum samples (n=195) were tested for BVDV antibody using ELISA, and for BVDV antigen using a real-time PCR assay. Faecal samples were collected from 143 animals; FEC were measured, and samples pooled for larval culture.
No haemoplasma organisms were present on blood smear examination. Of the 206 blood samples, two (from the same farm) were positive for Mhl by real-time PCR testing, giving a prevalence of infection with Mhl of 0.97%. Of the 195 serum samples tested, four (2.1%) were positive for antibodies to BVDV; animals with BVDV antibodies were from 3/15 (20%) farms, none of which farmed cattle. None of the serum samples were positive by PCR for BVDV antigen. The median FEC was 50 epg (min 0, max 4,700), with 55/143 (38.5%) samples having 0 epg, and 33/143 (23.1%) having ≥250 epg. Haemonchus spp. were the most common nematodes present in faecal larval cultures from the North Island. Log FEC was negatively associated with PCV (p=0.02), and was higher in males than females (p<0.001), and in animals that were positive compared with negative for Mhl (p=0.022).
The number of alpaca infected with Mhl was low, as was the seroprevalence of BVDV. Gastrointestinal parasitism was, however, a common finding in this sample of New Zealand alpaca.
确定成年新西兰羊驼（小羊驼）样本中溶血隐秘支原体（Mhl）感染率、牛病毒性腹泻病毒（BVDV）抗体和BVDV抗原，以及粪便线虫卵计数（FEC）升高的动物比例。
从新西兰各地15个农场采集的175只羊驼以及送往诊断实验室进行常规血液学检查的31份样本中获取血样。对170份血涂片进行显微镜检查以检测血支原体的存在，并从206份全血中提取DNA用于Mhl的实时PCR检测。测定193份样本的红细胞压积（PCV）。使用酶联免疫吸附测定法（ELISA）检测195份血清样本中的BVDV抗体，并使用实时PCR测定法检测BVDV抗原。从143只动物采集粪便样本；测量FEC，并将样本合并用于幼虫培养。
血涂片检查未发现血支原体。在206份血样中，两份（来自同一农场）通过实时PCR检测Mhl呈阳性，Mhl感染率为0.97%。在检测的195份血清样本中，四份（2.1%）BVDV抗体呈阳性；有BVDV抗体的动物来自3/15（20%）个农场，这些农场均未养殖牛。血清样本中通过PCR检测BVDV抗原均为阴性。FEC中位数为50个虫卵/克（范围0至4700），55/143（38.5%）份样本FEC为0个虫卵/克，33/143（23.1%）份样本FEC≥250个虫卵/克。血矛线虫属是北岛粪便幼虫培养中最常见的线虫。FEC对数与PCV呈负相关（p=0.02），雄性高于雌性（p<0.001），Mhl阳性动物高于阴性动物（p=0.022）。
感染Mhl的羊驼数量较少，BVDV血清阳性率也较低。然而，胃肠道寄生虫感染在该新西兰羊驼样本中是常见现象。
