The seroprevalence and spatial distribution of liver fluke infection in a sample of West Coast and Canterbury dairy herds

IF 1.4 Q3 PARASITOLOGY

Veterinary parasitology, regional studies and reports Pub Date : 2025-02-01 DOI:10.1016/j.vprsr.2025.101201

A. Dowling , K.E. Lawrence , L. Howe , I. Scott , W. Pomroy

{"title":"The seroprevalence and spatial distribution of liver fluke infection in a sample of West Coast and Canterbury dairy herds","authors":"A. Dowling , K.E. Lawrence , L. Howe , I. Scott , W. Pomroy","doi":"10.1016/j.vprsr.2025.101201","DOIUrl":null,"url":null,"abstract":"<div><div>The West Coast region of the South Island of New Zealand is recognised as having a high prevalence of liver fluke infection, however, few studies have tested this assumption. This study aimed to estimate the seroprevalence and spatial distribution of liver fluke infection in most West Coast and some Canterbury dairy herds using bulk milk ELISA. Herds were bulk milk sampled on three occasions, twice, a week apart in March 2017 (<em>n</em> = 430 and <em>n</em> = 99) and once in October 2017 (<em>n</em> = 412). The concentration of liver fluke antibodies was estimated using the IDEXX Fasciolosis Verification ELISA (IDEXX Europe BV, Hoofdorp, The Netherlands) on these bulk milk samples. Herds were categorised according to the test instructions, with “medium” (≥20 % cows infected) or “strong” (≥50 % cows infected) results designated as production limiting. All herds were also sent a short questionnaire about awareness of liver fluke and treatment in their herds. The agreement between the IDEXX results for 99 herds sampled twice in March 2017, and between the IDEXX results for March and October for all herds was assessed with a Kappa test. There was a substantial agreement between the two March tests, kappa = 0.7 (95 % CI 0.58–0.82) and moderate agreement between the March and October samples kappa = 0.41 (95 % CI 0.34–0.48). The results of the questionnaire were linked to the IDEXX results, and the distribution of herds categorised by their IDEXX result plotted. At the March and October samplings 0/35 (0 %) and 0/27 (0 %) Canterbury herds, 248/395 (63 %) and 193/385 (50 %) of West Coast herds had a production limiting seroprevalence of liver fluke infection. Mapping showed that West Coast herds with a production limiting infection were clustered in coastal areas, whereas those without, were clustered in inland valleys. The odds of a coastal West Coast dairy herd having a production limiting seroprevalence of liver fluke were 10.7 (95 % CI, 6.6–17.3) times that of an inland herd in March and 8.6 (95 % CI, 5.4–13.8) times in October. There was no effect on IDEXX ELISA SP% (<em>p</em> = 0.92) of herds which were treated for liver fluke at dry off soon after the March test compared to their SP% in the following October test, soon after calving.</div><div>The results show that liver fluke infection is a potentially serious problem for West Coast dairy herds especially for those on coastal river plains prone to flooding.</div></div>","PeriodicalId":23600,"journal":{"name":"Veterinary parasitology, regional studies and reports","volume":"58 ","pages":"Article 101201"},"PeriodicalIF":1.4000,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Veterinary parasitology, regional studies and reports","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2405939025000085","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PARASITOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

The West Coast region of the South Island of New Zealand is recognised as having a high prevalence of liver fluke infection, however, few studies have tested this assumption. This study aimed to estimate the seroprevalence and spatial distribution of liver fluke infection in most West Coast and some Canterbury dairy herds using bulk milk ELISA. Herds were bulk milk sampled on three occasions, twice, a week apart in March 2017 (n = 430 and n = 99) and once in October 2017 (n = 412). The concentration of liver fluke antibodies was estimated using the IDEXX Fasciolosis Verification ELISA (IDEXX Europe BV, Hoofdorp, The Netherlands) on these bulk milk samples. Herds were categorised according to the test instructions, with “medium” (≥20 % cows infected) or “strong” (≥50 % cows infected) results designated as production limiting. All herds were also sent a short questionnaire about awareness of liver fluke and treatment in their herds. The agreement between the IDEXX results for 99 herds sampled twice in March 2017, and between the IDEXX results for March and October for all herds was assessed with a Kappa test. There was a substantial agreement between the two March tests, kappa = 0.7 (95 % CI 0.58–0.82) and moderate agreement between the March and October samples kappa = 0.41 (95 % CI 0.34–0.48). The results of the questionnaire were linked to the IDEXX results, and the distribution of herds categorised by their IDEXX result plotted. At the March and October samplings 0/35 (0 %) and 0/27 (0 %) Canterbury herds, 248/395 (63 %) and 193/385 (50 %) of West Coast herds had a production limiting seroprevalence of liver fluke infection. Mapping showed that West Coast herds with a production limiting infection were clustered in coastal areas, whereas those without, were clustered in inland valleys. The odds of a coastal West Coast dairy herd having a production limiting seroprevalence of liver fluke were 10.7 (95 % CI, 6.6–17.3) times that of an inland herd in March and 8.6 (95 % CI, 5.4–13.8) times in October. There was no effect on IDEXX ELISA SP% (p = 0.92) of herds which were treated for liver fluke at dry off soon after the March test compared to their SP% in the following October test, soon after calving.

The results show that liver fluke infection is a potentially serious problem for West Coast dairy herds especially for those on coastal river plains prone to flooding.

查看原文本刊更多论文

西海岸和坎特伯雷奶牛群肝吸虫感染的血清流行率和空间分布

新西兰南岛西海岸地区被认为是肝吸虫感染的高发地区，然而，很少有研究证实这一假设。本研究旨在利用散装牛奶ELISA法测定美国西海岸和坎特伯雷部分奶牛的肝脏吸虫感染的血清阳性率和空间分布。2017年3月（n = 430和n = 99）和2017年10月（n = 412）分别对牛群进行了三次、两次、每周一次的散装牛奶取样。使用IDEXX片形吸虫病验证ELISA （IDEXX Europe BV, Hoofdorp, The Netherlands）对这些散装牛奶样品进行肝吸虫抗体浓度估计。根据测试说明对牛群进行分类，以“中等”（≥20%的奶牛感染）或“强烈”（≥50%的奶牛感染）结果指定为生产限制。同时，还向所有畜群发送了一份简短的问卷，了解其畜群对肝吸虫的认识和治疗情况。通过Kappa测试评估了2017年3月两次采样的99个牛群的IDEXX结果之间的一致性，以及3月和10月所有牛群的IDEXX结果之间的一致性。3月和10月的两个样本kappa = 0.7 (95% CI 0.58-0.82), kappa = 0.41 (95% CI 0.34-0.48)，两者之间有很大的一致性。调查问卷的结果与IDEXX结果相关联，并绘制了按其IDEXX结果分类的畜群分布。在3月和10月取样时，坎特伯雷畜群的0/35（0%）和0/27(0%)，西海岸畜群的248/395（63%）和193/385（50%）有生产限制型肝吸虫感染的血清阳性率。制图显示，受生产限制感染的西海岸畜群聚集在沿海地区，而未受感染的畜群则聚集在内陆山谷。3月份，西海岸沿海奶牛群的产限血清肝吸虫患病率是内陆奶牛群的10.7 （95% CI, 6.6-17.3）倍，10月份是8.6 （95% CI, 5.4-13.8）倍。与产犊后不久的10月试验相比，在3月试验后不久干脱肝吸虫处理的牛群的IDEXX ELISA SP%无显著影响（p = 0.92）。结果表明，肝吸虫感染对西海岸的奶牛群来说是一个潜在的严重问题，特别是对那些易受洪水影响的沿海河流平原。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Veterinary parasitology, regional studies and reports Multiple-

CiteScore

2.90

自引率

7.10%

发文量

126

审稿时长

97 days

期刊介绍： Veterinary Parasitology: Regional Studies and Reports focuses on aspects of veterinary parasitology that are of regional concern, which is especially important in this era of climate change and the rapid and often unconstrained travel of people and animals. Relative to regions, this journal will accept papers of the highest quality dealing with all aspects of disease prevention, pathology, treatment, epidemiology, and control of parasites within the field of veterinary medicine. Also, case reports will be considered as they add to information related to local disease and its control; such papers must be concise and represent appropriate medical intervention. Papers on veterinary parasitology from wildlife species are acceptable, but only if they relate to the practice of veterinary medicine. Studies on vector-borne bacterial and viral agents are suitable, but only if the paper deals with vector transmission of these organisms to domesticated animals. Studies dealing with parasite control by means of natural products, both in vivo and in vitro, are more suited for one of the many journals that now specialize in papers of this type. However, due to the regional nature of much of this research, submissions may be considered based upon a case being made by the author(s) to the Editor. Circumstances relating to animal experimentation must meet the International Guiding Principles for Biomedical Research Involving Animals as issued by the Council for International Organizations of Medical Sciences (obtainable from: Executive Secretary C.I.O.M.S., c/o W.H.O., Via Appia, CH-1211 Geneva 27, Switzerland).