宁夏部分地区奶牛场犊牛腹泻病原调查分析

为了明确宁夏地区奶牛犊牛腹泻的发病情况及引起腹泻的病原微生物种类,随机采集宁夏地区10个规模化奶牛场有腹泻症状的132头0~60日龄奶牛犊牛腹泻粪便样品,采用抗原快速检测试剂盒对轮状病毒、冠状病毒、隐孢子虫、大肠埃希氏菌K99、贾第鞭毛虫进行病原检测;采用麦克马斯特氏法进行艾美耳球虫检测。结果显示,132份样品中共检出95份阳性粪便,6种病原平均检出率为71.96%。10个牧场检出率各有不同,最低检出率33.33%,最高检出率为100%。隐孢子虫检出率为40.00%(38/95),轮状病毒检出率43.16%(41/95),冠状病毒检出率为34.74%(33/95),大肠埃希氏菌K99检出率为3.16%(3/95),贾第鞭毛虫检出率为25.26%(24/95),艾美耳球虫检出率为5.26%(5/95)。隐孢子虫、轮状病毒和冠状病毒之间的样本阳性率差异不显著(P>0.05);隐孢子虫和轮状病毒样本阳性率与大肠埃希氏菌K99样本阳性率差异极显著(P<0.01);贾第鞭毛虫样本阳性率与隐孢子虫、轮状病毒、大肠埃希氏菌K99、球虫样本阳性率差异极显著(P<0.01)。在检出的95份阳性样品中,最多出现3种病原混合感染。其中单一病原感染阳性样品占61.05%(58/95),以隐孢子虫感染比例最大,与冠状病毒和大肠埃希氏菌阳性率相比差异极显著(P<0.01);2种病原混合感染样品占28.42%(27/95),以轮状病毒和冠状病毒混合感染比例最大,与轮状病毒和贾第鞭毛虫混合感染阳性率、隐孢子虫和冠状病毒混合感染阳性率差异显著(P<0.05);3种病原混合感染样本占10.53%(10/95),以隐孢子虫、轮状病毒、冠状病毒混合感染比例最大,但与其他3种不同病原混合感染阳性率相比差异不显著(P>0.05)。结果表明,引起宁夏部分奶牛场0~60日龄奶犊牛腹泻病原体中,隐孢子虫、轮状病毒和冠状病毒感染较为严重。     

宁夏地区犊牛腹泻的病原调查

为了解宁夏地区奶牛犊牛腹泻的病原微生物种类及流行病学情况,2017年6月至12月对宁夏地区20个牧场有临床腹泻症状的犊牛,随机采集127份腹泻粪便样品,采用快速检测试剂盒对轮状病毒、隐孢子虫、大肠杆菌和贾第鞭毛虫4种病原微生物进行了抗原检测。结果显示:在127份腹泻粪样中,轮状病毒的阳性检出率为32. 28%(41/127),隐孢子虫的阳性检出率为25. 20%(32/127),大肠杆菌阳性检出率为11. 02%(14/127),贾第鞭毛虫阳性检出率为4. 72%(6/127)。结果表明:宁夏部分奶牛养殖区犊牛已经存在着较为严重的轮状病毒和隐孢子虫病感染,此调查为宁夏制定科学有效的综合防控措施提供了有效依据,对促进宁夏地区奶产业健康持续发展具有重要意义。     

不同养殖模式下山羊隐孢子虫感染分析及基因型鉴定

为探讨四川部分地区不同养殖模式下成年山羊隐孢子虫的感染差异以及感染虫种基因型,分别采集了规模化养殖模式和散养模式各6个养殖场共342份新鲜粪便,采用改良饱和蔗糖溶液漂浮法处理后提取粪便DNA,经套式PCR扩增18S rRNA基因,产物测序后进行遗传进化分析。结果:采样地区山羊隐孢子虫总感染率为4.7%,12个养殖场中4个养殖场(名山、纳溪、邻水和双流)存在隐孢子虫感染,感染率2.5%～19.2%,且4个隐孢子虫感染阳性场均为散养模式。序列分析表明,感染虫种为肖氏隐孢子虫(Cryptosporidium xiaoi)和猪隐孢子虫(C.suis),并以肖氏隐孢子虫为主(68.7%)。本试验初步表明,规模化养殖模式和散养模式下山羊隐孢子虫感染存在差异(P0.01);首次在成年山羊中检出猪隐孢子虫虫种,序列分析表明所获得的猪隐孢子虫序列与人源猪隐孢子虫序列完全一致,提示此次分离的羊源猪隐孢子虫为人兽共患隐孢子虫种。     

烟台部分地区奶牛隐孢子虫病调查

为了解奶牛隐孢子虫在烟台地区的流行情况,从烟台市的海阳、莱阳、牟平和招远4个地区6个奶牛场采集粪便样品565份,采用实时荧光定量聚合酶链反应法进行检测,分析奶牛隐孢子虫感染与腹泻、季节、年龄等方面的相关性.结果表明,隐孢子虫总感染率为10.44%(59/565),其中发生腹泻的奶牛隐孢子虫感染率为20.13(32/15...     

宁夏牛隐孢子虫感染情况调查研究

为了解宁夏地区牛隐孢子虫感染情况,在宁夏5个地级市中的10个县(区)随机抽取10个规模牛场,采集牛粪便样品600份,用牛隐孢子虫抗原检测试剂盒进行ELISA检测。结果显示,在600份样品中,有157份样品隐孢子虫阳性,阳性率为26.17%。其中奶牛的阳性率为10.42%,肉牛的阳性率为36.67%,两者差异极显著(P0.01)。不同地区牛的隐孢子虫阳性率不同,其中奶牛的阳性率在1.67%~23.33%之间,肉牛的阳性率在16.67%~63.33%之间,均差异极显著(P0.01)。不同年龄阶段牛的阳性率也不同,育成奶牛、成年奶牛以及成年肉牛的阳性率较高,分别达11.25%、11.25%和41.67%。该研究首次采用牛隐孢子虫抗原检测试剂盒对宁夏5个市的规模养殖牛场进行检测,为深入了解该地区牛隐孢子虫流行情况、制定有效的防控措施提供了依据。     

保定地区奶牛源隐孢子虫的分离与基因鉴定

为了解保定地区奶牛源隐孢子虫感染情况,从当地3个奶牛场随机采集145份奶牛粪便经饱和蔗糖溶液漂浮后直接镜检和抗酸染色后镜检,阳性样品采用PCR方法扩增18S rRNA基因,同时将扩增出的目的片段进行克隆和序列分析,并将分离株与其他11个隐孢子虫参考株的18S rRNA序列进行比对和遗传距离比较。结果表明:有10份粪便样本为隐孢子虫阳性,感染率为6.9%(10/145),不同奶牛场、年龄段奶牛隐孢子虫感染率有显著性差异(P0.05)。10份粪便样品采用PCR方法扩增后有7份为18S rRNA基因阳性,扩增出的18S rRNA部分基因片段长528 bp。保定地区隐孢子虫分离株扩增的基因序列与牛源隐孢子虫18S rRNA基因序列(Gen Bank登录号为HQ179571)同源性最高,确定保定地区分离到的奶牛源隐孢子虫为牛隐孢子虫。     

宁夏部分地区奶牛犊牛隐孢子虫感染情况调查

为了解宁夏地区犊牛隐孢子虫的感染情况,从3个市8个规模化奶牛场采集272份犊牛粪便样品,利用巢氏PCR技术对18S rRNA基因位点进行检测和分析。结果显示,隐孢子虫的总感染率为12.88%,银川市隐孢子虫感染率为16.89%,吴忠市隐孢子虫感染率为6.94%,石嘴山市隐孢子虫感染率为9.62%,三者差异不显著(P0.05),断奶前、后感染率分别为14.14%,12.14%。序列处理分析发现3种隐孢子虫,分别为牛隐孢子虫(Cryptosporidium bovis,C.bovis)、瑞氏隐孢子虫(Cryptosporidium ryanae,C.ryanae)和微小隐孢子虫(Cryptosporidium parvum,C.parvum),其中C.bovis分离率最高(54.29%)。研究表明这些地区犊牛隐孢子虫感染比较普遍,且感染的虫种有3种,其为深入了解宁夏部分地区隐孢子虫的分子流行情况提供了参考数据。     

西北部分地区藏香猪隐孢子虫感染情况研究

为了解我国西北部分地区藏香猪隐孢子虫的感染和种类分布,从陕西省和青海省采集了共450份藏香猪新鲜粪便样品,基于隐孢子虫18S rRNA基因的分子生物学方法对粪便样品中隐孢子虫感染情况及其种类进行了研究。结果显示,藏香猪隐孢子虫总感染率为14.2%,青海省藏香猪的感染率(23.9%)显著高于陕西省(3.7%)(P0.01);不同年龄段藏香猪隐孢子虫感染率差异显著(P0.01),其中断奶后仔猪感染率(42.9%)最高,而哺乳仔猪和成年猪均未检测到隐孢子虫的感染;序列分析发现,藏香猪的隐孢子虫均为Cryptosporidium scrofarum。研究结果为藏香猪隐孢子虫病的防控提供了基础数据。     

南京地区畜禽隐孢子虫感染情况调查

应用改良抗酸染色法对南京地区猪、奶牛、兔、犬、蛋鸡和鹅粪便样品进行隐孢子虫卵囊检测,调查隐孢子虫的感染情况。结果显示:南京地区奶牛、猪、兔和犬粪样品的阳性率分别为17.80%(34/191)、12.29%(29/236)、14.10%(22/156)和21.05%(20/105),差异均不显著(χ2<2.70,P>0.05);产仔母畜与仔畜的感染率之间差异不显著(P>0.05);鹅隐孢子虫感染率(16.67%,17/102)显著高于蛋鸡(7.74%,13/168)(χ2=5.12,P<0.05)。说明南京地区动物隐孢子虫感染率较高,母畜在仔畜隐孢子虫感染中发挥着重要作用。     

河南省山羊隐孢子虫流行病学调查

对河南省4个山羊场进行了隐孢子虫病流行病学调查.采集山羊粪样1 017份,以饱和蔗糖漂浮法和改良抗酸染色法检查,结果共检出隐孢子虫卵囊阳性山羊粪样28份,平均感染率为2.75%;有2个山羊场检出隐孢子虫卵囊,场感染率为50%;中牟某羊场阳性率最高,达4.95%;在各年龄段中,2～4月龄山羊隐孢子虫感染率最高,达5.43%;山羊隐孢子虫感染可能与季节有关;所检出的隐孢子虫卵囊经形态学观察,初步鉴定为微小隐孢子虫(Cryptosporidium parvum).     

Prevalence of Giardia and Cryptosporidium in beef cows in southern Ontario and in beef calves in southern British Columbia

In 1998 and 1999, fecal samples were collected from 669 beef cows on 39 farms located within 10 counties of Ontario. Overall prevalences of Giardia, Cryptosporidium muris, and Cryptosporidium parvum in cows were 8.7%, 10.6%, and 18.4%, respectively. Of the 39 farms sampled, Giardia was detected on 64%, Cr. muris on 72%, and Cr. parvum on 90%. Cryptosporidium parvum was detected in 28% of the cows in 1998 and in 5.2% in 1999. Differences between the 2 y were attributed to sampling during calving in 1998 and during gestation in 1999. In 1998, Giardia, Cr. muris, and Cr. parvum were detected in herds provided with municipal water. In 1998, 193 calves were sampled from 10 farms, representing 4 watersheds, in British Columbia. Thirty-six percent of the calves exhibited signs of diarrhea. Overall prevalences of Giardia and Cryptosporidium spp. in calves were 36% and 13%, respectively. There was evidence that calves with Giardia were more likely to develop scours. Restricting cattle from surface water during periods of high shedding may reduce watershed contamination.     

Longitudinal investigation of protozoan parasites in meat lamb farms in southern Western Australia

In this study, 96 faecal samples were collected from pregnant Merino ewes, at two broad-acre, commercial sheep farms in southern Western Australia, on two separate occasions (16 and 2 weeks prior to lambing). Following lambing, 111 (Farm A) and 124 (Farm B) female crossbred lambs (2-6 weeks old), were individually identified using ear tags (a numbered tag and a radio-frequency tag). A total of 1155 faecal samples were collected only from these individually identified lambs on five separate sampling occasions. All samples were screened using PCR to detect Cryptosporidium (18S rRNA and actin loci) and Giardia duodenalis (glutamate dehydrogenase and triosephosphate isomerise loci). The overall prevalences (lambs positive for a parasite on at least one of the five samplings) at Farm A and B were 81.3% and 71.4%, respectively for Cryptosporidium and similarly 67.3% and 60.5% for Giardia, respectively. Cryptosporidium and Giardia prevalences at individual samplings ranged between 18.5 and 42.6% in lambs and were <10% in the ewes. Cryptosporidium xiaoi was the most prevalent species detected at all five samplings and was also isolated from lamb dam water on Farm B. Cryptosporidium ubiquitum was most commonly detected in younger lambs and Cryptosporidium parvum was detected in lambs at all five samplings, typically in older lambs and as part of a mixed species infection with C. xiaoi. A novel, possibly new genotype (sheep genotype I), was identified in six Cryptosporidium isolates from Farm B. Giardia duodenalis assemblage E was the most common genotype detected at all five samplings, with greater proportions of assemblage A and mixed assemblage A and E infections identified in older lambs. This longitudinal study identified high overall prevalences of Cryptosporidium and Giardia in lambs grazed extensively on pastures, while reinforcing that sampling a random selection of animals from a flock/herd on one occasion (point prevalence), underestimates the overall prevalence of these parasites in the flock/herd across an extended time period. Based on these findings, grazing lambs were identified as a low risk source of zoonotic Cryptosporidium and Giardia species/genotypes, with these protozoa detected at all five samplings in some lambs, indicating that these individuals were either unable to clear the naturally acquired protozoan infections or were repeatedly re-infected from their environment or other flock members.     

Molecular and immunohistochemical detection of assemblage E, Giardia duodenalis in scouring North Dakota calves

Despite many reports on the shedding of Giardia parasites by scouring calves, the role of Giardia as a cause of calf diarrhea is still controversial. To elucidate the role of Giardia duodenalis in calf scours, diagnostic samples from 189 scouring calves were tested by different assays during a 1-year-study period. Giardia antigens were detected in 22/189 scouring calves by a fecal-based enzyme-linked immunosorbent assay and 10 of these were positive for assemblage E, G. duodenalis by polymerase chain reaction. Giardia trophozoites were demonstrated by immunohistochemistry in intestinal sections from five calves in which the parasites were spatially distributed in areas of microscopically detectable enteritis. Our data suggest that under certain circumstances, Giardia may cause intestinal lesions leading to calf scours. Gnotobiotic calf-based infectivity studies are needed if the pathogenicity of Giardia in calves is to be definitively determined.     

Experimental infection of calves and sheep with bovine Giardia isolates

9 Giardia-free calves were artificially infected with 1.5-5.1 x 10(6) Giardia cysts originating from Swiss cattle ("bovine isolates"). In 4 of these animals the course of infection was examined. After prepatent periods of 7-8 days all calves excreted high numbers of Giardia cysts for 60-112 days. During patency on 44% of the examination days Giardia cysts and antigen could be detected simultaneously in faecal samples using the flotation method and a sandwich-ELISA, respectively. With the exception of light diarrhoea lasting only for some days at the beginning of patency no other symptoms occurred. Further 5 artificially infected calves were submitted to autopsy. Giardia trophozoites were detected in 4 calves in the jejunum and in 1 animal in the ileum (peroxidase-antiperoxidase method). All animals were simultaneously infected with Campylobacter spp. and/or Rota- and Corona-virus. Electronmicroscopically mucosal attachment sites of Giardia trophozoites had intact microvilli and enterocytes. In various parts of the intestine blunting and flattening of the villi and cellular infiltrations of the mucosa were present. These alterations in calves are generally associated with bacterial and/or viral infections of calves. A Swiss bovine Giardia cyst-isolate was transmitted to 4 Giardia-free conventionally maintained lambs which excreted Giardia cysts after prepatent periods of 10-21 days for 31-61 days.     

The efficacy of a Giardia lamblia vaccine in kittens.

Twenty kittens were vaccinated with a Giardia lamblia vaccine prepared on a commercial scale on day 0 and boosted on day 21 (group 1); while 10 kittens received only saline (group 2). These kittens were challenged on day 35 with 10(6) Giardia lamblia trophozoites by a surgical intraduodenal injection. Three control kittens were not vaccinated and not challenged (group 3). Following challenge, Giardia vaccinated kittens had significantly fewer days in which abnormal stools were observed and reduced food intake occurred compared to saline injected animals. The rate of weight gain between group 1 and group 2 animals was not different in the prechallenge period (day 0 to day 35), but vaccinated animals had a significantly higher weight gain in the postchallenge period (P < 0.05). On day 56, all vaccinated animals were not passing cysts in their feces, while 40% of saline injected kittens had Giardia cysts in their feces. In vaccinated kittens, cysts were never demonstrated in 45% of the animals, while cysts were detected in 90% of the saline injected kittens. Viability of the cysts in vaccinated kittens was 38% while the cysts viability in saline injected kittens was 99%. On postmortem examination, trophozoites could be detected in 5% of vaccinated kittens and 60% of saline injected kittens. Vaccination produced an elevated Giardia specific serum IgG and IgA response prior to challenge and throughout the postinfection period. The Giardia infection in the saline injected group did not induce an elevated specific serum response. Giardia vaccination of kittens provides protection in kittens from an experimental challenge by reducing or eliminating intestinal trophozoites and fecal cyst excretion.     

Prevalence of Cryptosporidium, Giardia and Eimeria infections in post-weaned and adult cattle on three Maryland farms

The prevalence of Cryptosporidium, Giardia and Eimeria, in healthy, asymptomatic, post-weaned and mature cattle was investigated on three Maryland farms. One farm, a dairy research facility, had 150 multiparous Holstein milking cows; 24 were examined and Cryptosporidium andersoni was detected in three (12.5%) but neither Giardia nor Eimeria was detected. The second farm, a commercial dairy, had 57 multiparous Holstein milking cows and an equal number of heifers. Of 19 cows examined, C. parvum, Giardia duodenalis, and Eimeria bovis and/or E. ellipsoidalis were detected in two (10.5%), two (10.5%) and one (5.26%) cow, respectively. Of 23 heifers examined, C. parvum, Giardia, and E. bovis and E. ellipsoidalis, was detected in two (8.7%), four (17.4%), and five (21.7%), heifers, respectively. The third farm, a beef cattle breeding and genetics research facility, had 180 7- to 9-month old purebred black Angus. Of 118 examined for C. parvum and Giardia, 34 (28.8%) and 44 (37.3%) were positive, respectively, of 97 examined for E. bovis and/or E. ellipsoidalis 32 (33.0%) were positive. These findings, based on a method with a minimum detection level of 100 oocysts of C. parvum/g of feces, which underestimates the number of infected cattle, clearly demonstrate the presence of low level, asymptomatic infections in post-weaned and adult cattle in the United States and indicate the potential role of such cattle as reservoirs of infectious parasites.     

Impacts of naturally acquired protozoa and strongylid nematode infections on growth and faecal attributes in lambs

On two separate sampling occasions, faecal samples were collected from lambs (2-5 months of age) grazing pasture on two separate sheep farms in southern Western Australia. Live weight, body condition score (BCS), faecal consistency score (FCS) and faecal dry matter percentage (DM%) were measured. Faecal samples were screened by PCR for Cryptosporidium (18S rRNA, actin and 60 kDa glycoprotein [gp60] loci), Giardia duodenalis (glutamate dehydrogenase [gdh] and β-giardin) and patent strongylid nematode infections (ITS-2 nuclear ribosomal DNA for Haemonchus contortus, Teladorsagia circumcincta, Trichostrongylus spp. Chabertia ovina and Oesophagostomum spp.). Faecal worm egg counts (WECs) were performed using a modified McMaster WEC technique. The WECs were adjusted for FCS and transformed using log(10)(adjusted WEC+25) prior to statistical analyses. Cryptosporidium, Giardia and Trichostrongylus spp. detected by PCR were associated with an increased risk of non-pelleted faeces (FCS ≥ 3.0) for both flocks. Cryptosporidium-positive lambs were 2.8-11.6 times more likely to have non-pelleted faeces and Giardia-positive lambs were 2.4-14.0 times more likely to have non-pelleted faeces compared to lambs negative for each respective parasite. Lambs positive for both Cryptosporidium and Giardia were 2.9-11.8 times more likely to have non-pelleted faeces than lambs positive for only one or neither of these parasites. Mixed internal parasite infections were found to have greater impacts on FCS and BCS than single infections. A higher number of internal parasites detected per lamb was associated with lower BCS and more loose faeces. The relationship between parasite detection and live weight or growth rate were inconsistent for both flocks. Adjusted WEC was correlated with FCS and faecal DM% for one flock only, although little or no correlation was found with live weight and growth rate for both flocks. Cryptosporidium ubiquitum and Cryptosporidium parvum were the most prevalent Cryptosporidium species isolated in the two flocks. Giardia assemblage E was the most commonly isolated genotype assemblage from both flocks, while assemblage A was isolated almost as frequently as assemblage E in the one flock. One flock was a potential source of zoonotic Cryptosporidium and the other flock was a potential source of zoonotic Giardia.     

The frequency and geographic distribution of Giardia infections in ruminants in Switzerland

In various districts (Cantons) of Switzerland 815 calves (a few days up to 6 months old), 382 lambs and 20 young goats (both groups 1-6 months old) were selected randomly for a single coprological examination (flotation method) for Giardia infection. In average 26.6% of the calves, 29.8% of the lambs and 4 of 20 young goats excreted Giardia cysts. In 9 Cantons the percentages of cyst excretors among the calves varied between 15 and 32, but these differences were not significant. Further there were no significant differences in the frequency of cyst excretion between calves of 3 different breeds and 2 age groups (up to 3 months old and 3 to 6 months). The intensity of cyst excretion was high and varied in random samples between 4.1 x 10(3) and 3.0 x 10(5) cysts per g of faeces in calves and between 2.2 x 10(3) and 1.6 x 10(5) in lambs. In 5 of 7 farms where calves and lambs were maintained simultaneously both animal species were Giardia infected. As expected, trophozoites of Giardia isolates from calves and lambs belonged to the Giardia duodenalis type and could not be differentiated on a morphological basis. Giardia cysts from calves (average measurements: 13.7 x 9.1 microns) and lambs (13.8 x 9.2 microns) were indistinguishable both morphologically and morphometrically. The results indicate that Giardia infections are frequent and geographically widely distributed in calves and lambs in Switzerland.     

Prevalence of Giardia spp. and Cryptosporidium spp. on dairy farms in southeastern New York state

A prevalence study was designed to determine the presence of Cryptosporidium spp. and Giardia spp. in the soil of 37 dairy farms in southeastern New York state. A sampling design was developed and used to collect soil samples from these farms. Areas on the farms which were considered to be potential sources of contamination to the environment were evaluated quantitatively using a multidimensional scale. This scale included factors which could have the potential to contribute to the risk of contamination of the environment with Giardia or Cryptosporidium. In addition, the runoff pathway from these areas was identified and sampling points along that pathway were determined. Using a sampling grid, sampling sites were determined and soil samples collected and analyzed individually for the following: presence of Giardia and Cryptosporidium, pH, gravimetric moisture content, and volumetric moisture content. Out of 782 soil samples, 17% were positive for Cryptosporidium and 4% were positive for Giardia. The pH of the soil ranged from 3.7 to 9.8 with a mean of 7.0. There was a significant association between the pH and the likelihood of detecting Cryptosporidium spp. As the pH increased, the likelihood of detecting an oocyst decreased. Gravimetric moisture content had a mean of 40% and a range from 7 to 86%. There was a significant association between the gravimetric moisture content and the likelihood of detecting Giardia in soil samples.     

Detection of Cryptosporidium parvum oocysts in environmental water in Hokkaido, Japan

Control of cryptosporidiosis is important in public health. Rivers that are polluted with Cryptosporidium and drinking water that is treated for drinking water production from polluted rivers could result in the waterborne disease of cryptosporidiosis. We carried out an epidemiological study of natural water supplies in Hokkaido, one of the largest dairy prefectures in Japan. To detect Cryptosporidium oocysts in environmental water, the filtration method was used for 28 samples, which were collected from 10 rivers. A method adapted from the United States Environmental Protection Agency (U.S. EPA) filtration method using a cartridge filter has been used for the collection of samples. Oocysts were separated from a pellet by discontinuous sucrose gradient method. Twelve samples were collected from 10 rivers and parasites were purified by iron (III) flocculation method. Cryptosporidium parvum oocysts were identified with the immunofluorescence antibody technique using DIF kit (Cellabs Pty. Ltd., Sydney/Australia). We detected Cryptosporidium oocysts in 6 out of 10 rivers sampled. Fifty percentage (14/28) of the samples were Cryptosporidium-positive. The average number of Cryptosporidium oocysts was 16.73/100 L (max. 80/100 L).