Symptomatic and Asymptomatic Protist Infections in Hospital Inpatients in Southwestern China

Subtype Distribution of Blastocystis spp. in Patients with Gastrointestinal Symptoms in Northern Spain

Limited molecular data exist on the prevalence and subtype distribution of Blastocystis spp., the most prevalent parasite in human and animal feces worldwide. A total of 44 different subtypes (STs) of Blastocystis are currently recognized based on the sequence of the small subunit ribosomal RNA (SSU-rRNA) gene. This is a molecular study of Blastocystis spp. in hospitalized patients with gastrointestinal symptoms in northern Spain. We analyzed 173 Blastocystis-positive patients with gastrointestinal symptoms by using nested PCR for molecular detection, subtype identification, phylogenetic analyses, and genetic diversity assessment. ST2 (34.1%) and ST3 (34.7%) predominated, followed by ST1 (15.6%) and ST4 (15.6%). Mixed infections with different subtypes were observed in some patients. Sequence analysis revealed for the first time in European humans the allele 88 (a variant of ST1). In other cases, alleles commonly found in animal samples were detected (allele 9 in ST2, allele 34 in ST3, and allele 42 in ST4). Phylogenetic analysis showed high variability in ST1 and ST2, suggesting a polyphyletic origin, while both ST3 and ST4 exhibited higher genetic homogeneity, indicating a possible monophyletic origin and recent transmission to humans. These data confirm Blastocystis spp. subtype diversity and may help in understanding the evolutionary processes and potential zoonotic transmission of this parasite.

Prevalence and Associated Risk Factors of Intestinal Parasites among Diarrheic Under-Five Children Attending Bahir Dar and Han Health Centers, Northwest Ethiopia: A Cross-Sectional Study

Background. Intestinal parasitic infection is one of the major public health problems in developing countries including Ethiopia. The problem is highly pronounced in children under five years of age who are not able to adhere to prevention and control precautions. Objective. To assess the prevalence of intestinal parasitic infections (IPIs) and associated factors among diarrheic children under five years of age attending Bahir Dar and Han Health Centers, Bahir Dar, Northwest Ethiopia. Methods. An institution-based cross-sectional study was conducted among diarrheic children less than five years of age at Bahir Dar and Han Health Centers, Northwest Ethiopia, 2020. A total of 221 diarrheic children less than five years of age were recruited using the convenience sampling technique. Data were collected using a pretested structured Amharic version questionnaire after obtaining informed consent from children’s parents or guardians. Approximately 1 mL of fresh fecal specimen was collected and subjected to direct saline wet mount microscopy. All data were entered into Epi Info version 7 and transferred to SPSS statistical software version 20 for analysis. Logistic regression was employed to assess risk factors associated with increased prevalence of intestinal parasitic infection in diarrheic children under five years of age, and a $P$ value < 0.05 was taken as statistically significant. Results. The overall prevalence of intestinal parasites was 19% ( $95\%\text{CI}=14–24.6$ ). The most prevalent intestinal parasites were Entamoeba histolytica/Entamoeba dispar (24 (10.86%)), Giardia lamblia (12 (5.43%)), and Ascaris lumbricoides (2 (0.9%)). Children’s mother/guardian washed their hands sometimes after the toilet ( $\text{AOR}=2.98$ , 95% CI: 1.09-8.18), children who always eat unwashed fruits and vegetables ( $\text{AOR}=4.63$ , 95% CI: 1.09–19.75), and children’s mother/guardian who had no knowledge about the mode of transmission ( $\text{AOR}=4.03$ , 95% CI: 1.04–15.64) were risk factors significantly associated with increased intestinal parasitic infections. Conclusion. The prevalence of intestinal parasitic infections was found low compared to the population prevalence reported by WHO. However, strengthening health education about food and personal hygiene of both children and their mothers/guardians is crucial to limit the transmission of IPIs.

Occurrence and subtyping of Blastocystis in coypus (Myocastor coypus) in China

BACKGROUND

Blastocystis is an anaerobic unicellular protist frequently detected in the gastrointestinal tracts of humans and animals worldwide. However, the prevalence and subtype distribution of Blastocystis in the coypu (Myocastor coypus) population have not been reported so far. The aim of this study was to determine the prevalence, genetic characteristics, and zoonotic potential of Blastocystis isolates detected in coypus in China.

RESULTS

A total of 308 fecal samples were collected from coypus in seven regions across China and subsequently examined. Blastocystis was detected in 44 (14.3%) specimens by nested PCR amplification of the small subunit ribosomal rRNA (SSU rRNA) gene. Further DNA sequencing and phylogenetic analyses resulted in the identification of two zoonotic known subtypes, ST4 and ST5, and an unknown subtype. ST4 was the most predominant subtype observed in the samples. ST5 infections were only observed in three coypus. Factors that were associated with prevalence of Blastocystis included age, geographical region and subtype. Interestingly, this is the first report about a potentially novel subtype infecting coypus.

CONCLUSIONS

This is the first comprehensive report of Blastocystis in M. coypus across a wide geographic range of China. A moderate degree of genetic divergence was observed. The presence of zoonotic subtypes in farmed M. coypus suggests that these animals have the potential to transmit blastocystosis to both humans and domestic animals. These findings provide a better understanding of the genetic diversity of Blastocystis in rodents and contribute towards the establishment of efficient blastocystosis control strategies in the investigated areas.