Outbreak of cryptosporidiosis due to Cryptosporidium parvum subtype IIdA19G1 in neonatal calves on a dairy farm in China

Abstract

a b s t r a c tNeonatal diarrhea is one of the most important syndromes in dairy cattle. Among enteropathogens, Cryptosporidium spp. are primary causes of diarrhea, but outbreaks due to cryptosporidiosis are rarely reported in cattle. From January to April in 2016, severe diarrhea was observed in over 400 neonatal dairy calves on a large dairy farm in Jiangsu Province of East China. Approximately 360 calves died due to watery diarrhea despite antibiotic therapy. In this study, 18 fecal specimens were collected from seriously ill calves on this farm during the diarrhea outbreak, and analysed for common enteropathogens by enzymatic immunoassay (EIA). In a post-outbreak investigation, 418 and 1372 specimens collected from animals of various age groups were further analysed for rotavirus and Cryptosporidium spp. by EIA and PCR, respectively, to assess their roles in the occurrence of diarrhea on the farm. Cryptosporidium spp. were genotyped using established techniques. Initial EIA tests showed that 15/18 seriously ill calves during the outbreak were positive for Cryptosporidium parvum, while 8/18 were positive for rotavirus. The overall infection rate of Cryptosporidium in pre-weaned calves on the farm was 22.7%, with odds of the Cryptosporidium infection during the outbreak 4.4-23.5 times higher than after the outbreak. Four Cryptosporidium spp. were identified after the outbreak including C. parvum (n = 79), Cryptosporidium ryanae (n = 48), Cryptosporidium bovis (n = 31), and Cryptosporidium andersoni (n = 3), with co-infections of multiple species being detected in 34 animals. Infection with C. parvum (73/79) was found in the majority of calves aged 3 weeks, consistent with the age of ill calves during the outbreak. All C. parvum isolates were identified as subtype IIdA19G1. In the post-outbreak investigation, C. parvum infection was associated with the occurrence of watery diarrhea in pre-weaned calves, C. ryanae infection was associated with moderate diarrhea in both pre-and post-weaned calves, while no association was identified between rotavirus infection and the occurrence of diarrhea. Results of logistic regression analysis further suggested that C. bovis infection might also be a risk factor for moderate diarrhea in calves. Thus, we believe this is the first report of a major outbreak of severe diarrhea caused by C. parvum IIdA19G1 in dairy calves. More attention should be directed toward preventing the dissemination of this virulent subtype in China.Ó

Seasonal monitoring of Cryptosporidium species and genetic diversity in neonatal dairy calves on two large-scale farms in Xinjiang, China

“…Our ndings indicate that C. parvum was clearly predominant in every season, whereas C. bovis and C. ryanae were found only occasionally. This is similar to two studies of cryptosporidiosis outbreaks in Ningxia and Jiangsu, in which the occurrence of C. parvum was signi cantly higher than that of C. bovis or C. ryanae [10,11]. Subtyping C. parvum revealed two zoonotic subtypes, IIdA14G1 and IIdA15G1.…”

“…In general, Cryptosporidium was signi cantly associated with calves younger than 2 weeks with diarrhea [29]. A previous study of a diarrhea outbreak among neonatal dairy calves in Jiangsu suggested that the prevalence of Cryptosporidium was signi cantly higher during the outbreak (80.3%) than after the outbreak (22.7%), and that the prevalence of Cryptosporidium in dairy calves less than 3 weeks old was much higher than in any other age group [11]. In a similar cryptosporidiosis outbreak in Ningxia, the highest prevalence of Cryptosporidium (83.3%, 40/48) was seen in 2-3-week-old calves with severe diarrhea [10].…”

“…The overall prevalence of Cryptosporidium in neonatal dairy calves on the two farms was 48.7% (185/380), which was similar to that in a report from Heilongjiang in northeastern China (47.7%, 72/151) [19], and higher than those in Hebei and Tianjin (2.6%, 9/351) [20] in northern China; Ningxia (10.2%,19/186 to 31.0%, 49/158) in three cases) [10,21,22 ], Shaanxi (24.7%, 46/186) [23], and Xinjiang (15.6%, 37/237) [24] in northwestern China; Henan (21.5%, 172/801) [14] and Hubei (15.8%, 42/265) [25] in central China; Sichuan (14.4%, 40/278) in southwestern China [26]; Shanghai (37.0%, 303/818) [27] and Jiangsu (22.7%, 139/612) [11] in eastern China; and Guangdong (24.0%, 93/388 and 6.4%, 19/297) in southern China [15,28].…”

“…Data on the global C. parvum subtypes in cattle indicate that although the IId subtypes are dominant in China, the IIa subtypes are more common in Europe, North America, and Australia. In China, cryptosporidiosis outbreaks were reported on two dairy farms in the Ningxia Autonomous Region (referred to as Ningxia hereafter) and Jiangsu Province, caused by C. parvum subtypes IIdA15G1 and IIdA19G1, respectively [10,11]. The IId subtypes have been detected in humans and various animal species, indicating that neonatal calves may be a reservoir for the transmission of human Cryptosporidium infections [12].…”

Genetic diversity of Cryptosporidium parvum in neonatal calves in Xinjiang, China

“…Gansu Provinces [9,11,12,[17][18][19]23]. Subtype IIdA19G1 was mostly found in Jiangsu, Henan, Shanghai, Xinjiang, Guangdong, Hebei, Tianjin, Beijing, and Heilongjiang Provinces [10,14,15,[21][22][23]25]. Subtype IIdA20G1 was found in Heilongjiang Province [11].…”