Prevalence and Molecular Characterization ofCyclospora cayetanensis, Henan, China

Abstract

To determine prevalence of Cyclospora cayetanensis infection in Henan, China, we conducted a study of 11,554 hospital patients. Prevalence was 0.70% (95% confidence interval 0.70% ± 0.15%), with all age groups infected. Most cases were found in the summer. Minor sequence polymorphisms were observed in the 18S rRNA gene of 35 isolates characterized.

Prevalence of Cyclospora cayetanensis and other enteropathogen among children under the age of 15 years in Biratnagar, Nepal

“…These findings are in agreement with the previous studies [11,19,[21][22][23]. In this study, high cases of parasitic infection including C. cayetanensis were found in the age group of 3-6 years.…”

Cyclospora cayetanensis

“…In Guatemala (Bern et al, 1999), Honduras (Kaminsky, 2002), Haiti (López et al, 2003), Cuba (Nuñez et al, 2003), Venezuela (Chacín-Bonilla et al, 2007), Nepal (Kimura et al, 2005;Tandukar et al, 2013), Turkey (Turgay et al, 2007), and Thailand (Thima et al, 2014) the infection was more frequent in school children less than 15 years of age. In Henan, China, children 7-17 years of age had the highest detection rate (Zhou et al, 2011). The causes for this age distribution pattern are not clear but may be related to predominant modes of exposure.…”

“…Analysis of the 18S rRNA gene of C. cayetanensis isolates and among members of C. colobi, C. papionis, and C. cercophiteci showed a significant distinct genetic variation among species and a minor genetic diversity within the species (Sulaiman et al, 2014). Examination of 18S rRNA gene sequences of isolates from China also revealed only minor sequence polymorphisms (Zhou et al, 2011). The intervening transcribed spacer 1 (ITS-1) is highly variable even within individual oocysts and is therefore not reliable for inferring relationships between strains (Olivier et al, 2001).…”

“…However, it is not uniform among different regions and defies easy explanation (Herwaldt, 2000). The seasonal trend of increased prevalence of cyclosporiasis described in various nations often coincides with warm periods of maximal rainfall as reported in Guatemala (Bern et al, 1999), Honduras (Kaminsky, 2002), Mexico (Orozco-Mosqueda et al, 2014), Jordan (Nimri, 2003), Nepal (Hoge et al, 1993(Hoge et al, , 1995Sherchand et al, 2001;Kimura et al, 2005;Bhandari et al, 2015), Indonesia (Fryauff et al, 1999), and China (Zhou et al, 2011).In contrast, infection has been more prevalent in the absence of rain during the drier and hotter months of the year in Lima, Peru (Madico et al, 1997;Bern et al, 2002) and Turkey (Turgay et al, 2007) and in cooler time in Haiti, where temperature fluctuations appear to be the moderator of the infection seasonality (Eberhard et al, 1999b).The seasonal variation of C. cayetanensis suggests that environmental factors are important in the life cycle of this parasite and that it is likely to be influenced by several of them such as rainfall, temperature, and humidity.…”

“…In contrast, the risk factors and routes of spread for C. cayetanensis in developing areas remain poorly understood. Variables related to water, eating fresh food, contact with soil, agricultural occupations, lack of hand washing, and factors associated with low socioeconomic status have been linked to infection (Wang et al, 2002;Chacin-Bonilla et al, 2007, 2008aZhou et al, 2011;Tandukar et al, 2013). The biologic and epidemiologic features of C. cayetanensis that facilitate transmission might involve an interplay among different routes of spread but the relative contributions of the different modes of transmission to the overall burden of cyclosporiasis are hard to quantify.…”