Prevalence of Balantidium coli infection in sows in Hunan province, subtropical China

Prevalence and molecular characterisation of Balantioides coli in pigs raised in Italy

Balantioides coli is the only ciliated protist of both human and veterinary interest and colonises the large intestine of several hosts, including humans and pigs. Given the scarcity of data on B. coli circulation in pigs in Italy, a study was planned to record its prevalence and genetic types and compare the analytical sensitivity of two copromicroscopic techniques. For this purpose, 880 faecal samples were collected from pigs raised in 22 farms located in northern Italy and analysed with the sedimentation and the FLOTAC® dual technique, employing sodium chloride and zinc sulphate flotation solutions, and the Cohen's kappa coefficient was calculated to assess the agreement between these methods. Conventional PCR to amplify the ribosomal internal transcribed spacer region (ITS) was subsequently performed on 22 samples, one for each farm, which were positive for B. coli cysts by sedimentation; when more than one sequence was detected in the chromatograms, the PCR products were cloned. Overall, 813 samples were positive for B. coli cysts by sedimentation (92.4%), and moderate concordance with the zinc-based FLOTAC® technique was observed, whereas the agreement was slight with the salt-based FLOTAC® technique. Among the 22 sequenced samples, type B was amplified in 19 samples, type A in two samples, and both A and B types were co-expressed in one sample. This study demonstrated a high prevalence of B. coli in Italian pigs; further insights are needed to trace its distribution and genetic polymorphism in other pig production categories and in humans, defining its public health significance.

Prevalence and sequence diversity of Balantioides coli in pigs in Xinjiang, China

Balantioides coli is a common intestinal parasitic protozoan in pigs. In the present study, 801 fecal samples of pigs from seven farms in Xinjiang were analyzed based on the ITS1-5.8S rRNA-ITS2 gene. The prevalence of B. coli was 4.2% (34/801), with the highest prevalence of 18.9% (18/95) occurring in Alaer, Xinjiang. B. coli was detected in all age groups (pre-weaned pigs, post-weaned pigs, fattening pigs and sows), with the highest rate in fatteners (6.9%, 9/129) and the lowest (1.2%, 2/169) in pre-weaned pigs. Significant differences (P = 0.000) were found among sampling sites but not among age groups (P = 0.084). Sequence analysis indicated that 34 sequence variants, including sequence type A (n = 11) and sequence type B (n = 23), occurred in all age groups. In this study, the existence of sequence type A suggested that B. coli poses a potential threat to human health. More studies are needed to better understand the distributions and public health significance of B. coli in China.

Balantidium coli; Rare and Accidental Finding in the Urine of Pregnant Woman: Case Report

Background

Balantidium coli is a ciliated protozoan parasite, which causes intestinal and extraintestinal infections in humans. It is transmitted feco-orally by ingesting infective cysts with food and water. Urinary balantidiasis may occur through contamination (direct spread from the anal area), secondarily to rectovaginal fistula and following immune suppression. Data about cases of urinary balantidiasis are rare in the world. Currently, there are no documented reports of urinary balantidiasis in Ethiopia. As our understanding, there are only eleven documented reports of urinary balantidiasis globally. However, cases of urinary balantidiasis among pregnant women have not been documented yet. The aim of this report is to alarm health professionals for considering the occurrence of such rare cases and conduct diagnosis.

Case Presentation

A 24-year old pregnant woman was admitted due to severe preeclampsia and preterm delivery at Debre Tabor Comprehensive Specialized Hospital, gynecology ward. Her urine was presented to inpatient laboratory for routine urinalysis. We detected unusual and ciliated parasite from her urine sediment characterized by its active and rotary motility through its cilia and possessing macro- and micro-nuclei, several food vacuoles and ingested red blood cells inside the cytoplasm. Hematuria, many white blood cells and epithelial cells were also detected from the urine sediment, which suggests genito-urinary tract infection due to this parasite. This rare parasite finding was confirmed to be B. coli.

Conclusion

The route of transmission and extraintestinal existence from this woman’s urine was unclear. It might be due to feco-oral transmission and spread to the genitourinary tract through direct anal contact. Moreover, it might be associated with immune suppression as she is pregnant woman.

Prevalence of Balantidium coli (Malmsten, 1857) infection in swine reared in South Italy: A widespread neglected zoonosis

Background and Aim:

Balantidiasis, caused by Balantidium coli (syn. Neobalantidium coli or B. coli), represents a neglected parasitic infection of zoonotic significance affecting a variety of hosts, including domestic pigs that are the main reservoir. B. coli has a direct life cycle with a fecal-oral route transmission that occurs mainly by the ingestion of food and water contaminated with cysts. The ingestion of meat contaminated during inappropriate slaughtering processes may represent a new potential route of transmission. Only a few studies have investigated the prevalence of B. coli in domestic pigs in Italy, despite its high prevalence and zoonotic significance. This study aimed to improve the knowledge on B. coli prevalence in domestic swine reared both in intensive and “en plein air” breeding systems in the south of Italy.

Materials and Methods:

The infection rate of B. coli in pigs bred in 15 different pig farms and regularly slaughtered in South Italy, in the Calabria region, was investigated. From 2017 to 2019, 177 terminal parts of the rectums of pigs, of which 91 commercial hybrids and 86 autochthonous (Nero Calabrese), reared, respectively, in intensive and “en plein air” breeding system, were tested for parasite detection. After the slaughtering, the terminal part of the rectum was sampled and transported to the laboratories and immediately processed. For the detection of trophozoites, fresh smears of feces were examined at light microscopy. Moreover, flotation was performed using a sodium chloride solution, then smears of feces were dispersed on microscope slides and examined at light microscopy. The observed parasites were identified at the species level using morphological characteristics.

Results:

B. coli was detected in a total of 83 (i.e., 46.89%) pigs, with a significantly higher prevalence (p<0.0001) found in commercial hybrid (i.e., 59/91-64.84%) pigs rather than in autochthonous ones (i.e., 24/86-27.91%). It follows that the infection was more common in pigs reared in the intensive breeding system than in “en plein air” ones (p<0.0001). The infection prevalence was higher in males than in females and lower in elder animals than in younger ones (p=0.012 and p<0.0001, respectively).

Conclusion:

The breeding system is likely the main discriminant for the parasite spread as well as the hygienic condition of the farms. Good manufacturing and hygiene practices along the food production chain are crucial in preventing human balantidiasis transmission by meat consumption. The high B. coli prevalence, the wide spectrum of host species, and its zoonotic significance push toward a greater public interest.

Balantioides coli

Balantioides coli (=Balantidium coli) is the only ciliate that parasitizes humans. Pigs are the main reservoir. Other species, as camels, cattle, donkey, sheep and goat have been also proposed as reservoirs for human infections. The parasite has a direct life cycle, being transmitted by the faecal-oral route. This type of cycle and the large number of host species imply an important potential for zoonotic transmission of the parasite. Infections are most commonly found in tropical and temperate regions, with prevalence up to 100% in pigs; high prevalence values have been also recorded in some non-human primates and camels. In humans, prevalence is usually under 10% in the population at risk. The main epidemiological factors involved in the transmission of this parasite include close contact with pigs, lack of basic sanitation infrastructures (water supply, wastewater disposal) and hygiene. Individual health status, intestinal microbiota and diet are also important for the onset of the infection. Outbreaks caused by this parasite are rare; those reported to date were related to poor hygienic conditions or to catastrophic natural disasters. Balantioides coli infections can be asymptomatic and symptomatic, which can be chronic (with intermittent diarrhoea), or acute (a dysenteric form which can be life-threatening). Efective treatments include tetracycline, iodoquinol and 5-nitroimidazole compounds (metronidazole, secnidazole). The main effective individual preventive measure is the use of disinfected water for drinking and other uses. Adequate water supply infrastructures, proper disposal of wastewater and animal faeces, and regular monitoring programs on farms will help limit transmission.

Molecular characterization of Balantioides coli in pigs from Shaanxi province, northwestern China

Balantioides coli (syn. Balantidium coli) is an important zoonotic but usually neglected protozoa infecting human and a great number of animals, and the pig was considered to be the most important natural host and reservoir. However, no information about the infection of B. coli in pigs in northwestern China was available. In the present study, the prevalence and genetic diversity of B. coli in pigs in Shaanxi province were investigated. A total of 560 fecal samples were collected from pigs of four age groups in five different geographical regions and analyzed by using PCR targeting the ITS1-5.8S rRNA-ITS2 gene fragment. The infection of B. coli was detected in all age groups and regions, with the total prevalence of 16.8% (94/560). Significant differences (P < 0.01) in prevalence were found among four investigated age groups, with the highest in fatteners (38.8%) and the lowest in adults (5.7%). The prevalence was also significantly (P < 0.01) different among pigs from five sampling regions. Sequence analysis revealed two genetic variants, namely, A and B, in these investigated pigs, and both of them were detected in all age groups and regions, with the latter as the predominant one. Further, sixty-eight different haplotypes were found, with 19 and 49 belonged to genetic variants A and B, respectively. The findings in the present study indicated wide distribution and high diversity of B. coli in pigs in Shaanxi province and provided fundamental data for implementing control strategies on B. coli infection in pigs as well as other hosts in this province.

Balantidium coli in domestic animals: An emerging protozoan pathogen of zoonotic significance

Balantidium coli (B. coli) is an emerging ciliated protozoan parasite of zoonotic importance which causes a disease balantidiasis in a variety of host species including pigs, camels, ruminants, equines and even human. This disease has a cosmopolitan distribution with high prevalence rates in tropical and sub-tropical areas of the world due to favorable geo-climatic conditions for the development and survival of the parasite in these regions. Main reservoir hosts for this pathogen are pigs and animals; acquire infection mainly by the ingestion of the food or water contaminated with the porcine feces. The infected animal manifests clinical signs of anorexia, dehydration, profuse watery diarrhea and retarded growth. Wet mount slide prepared from intestinal scrapings and fecal material is used for the identification of trophozoites and cysts stages of this parasite. PCR can also be used to confirm the parasite. Secnidazole, oxytetracycline and metronidazole have varying efficacy against B. coli infection in various domestic animal species. There is no comprehensive literature available on the occurrence and distribution of the infection at international level. Therefore, the published data between 1989 and 2019 regarding this disease is critically analyzed to provide a detailed overview on this pathogen with special emphasis on geographical distribution of B. coli in domestic animals and different therapeutic agents used to treat this infection. This review will pinpoint the endemic regions which may be a source of potential disease outbreaks and will also help in application of more effectual control strategies against balantidiasis.

The First Case of Diarrhoea in Tibetan Sheep, Ovis aries, Caused by Balantidium coli in the Qinghai Tibetan Plateau Area, China

This study was carried out to determine the pathogen-causing diarrhoea in sheep Ovis aries in the Qinghai Tibetan Plateau Area, China. A trophozoite was identified as species of ciliate alveolates infecting the sheep based on morphological characteristics examined by microscope. It was mostly spherical, colourless and transparent, with many vesicles. Macronucleus and contractile vacuoles could not be distinguished. Size of the trophozoite was 80–180×70–150 μm and its surface was covered with cilia. Molecular analysis based on sequences of 18S rRNA and ITS genes confirmed the ciliate species as Balantidium coli. According to the literature, there have been many epidemiological investigations of B. coli infection in pigs, monkeys and humans. To our knowledge, this was the first report of B. coli infections in sheep in the Qinghai Tibetan Plateau Area of China, or eleswhere around the world. Importantly, the sheep case was rare but raised our concern that B. coli may spread across species and expand its host range.

Prevalence and Phylogenetic Analyses of Trichuris suis in Pigs in Hunan Province, Subtropical China

Trichuris suis infection in pigs is ubiquitous in intensive and extensive farms, which causes potential threat to human health. The objective of this research was to investigate the prevalence of T. suis in pigs in Hunan province. Total 2,267 fresh fecal samples distributed in 28 pig farms from 7 different administrative regions (Hunan province) were evaluated for the existence of T. suis eggs using saturated NaCl floating method. The average infection rate of T. suis in pigs was 8.91% in Hunan province. To determine genetic variation of the gained T. suis isolates in the present study, the internal transcribed spacer (ITS) regions from nuclear ribosomal DNA (rDNA) of 7 T. suis isolates were cloned and analyzed. Nucleotide diversities were 1.0–3.5% and 0–3.8% for ITS-1 and ITS-2, respectively. Phylogenetic analyses indicated that all isolates collected in the present study and T. suis available in Genbank generated a monophyletic clade. The present investigation revealed high infection rates of T. suis in pigs in Hunan province, which shed light on making effective measures to prevent and control T. suis infection in pigs in Hunan province.