Urinary infection due to Balantioides coli: a rare accidental zoonotic disease in an addicted and diabetic young female in Iran

Uninvited guest, Balantidium coli in urine in a patient with bladder cancer: A case report and review of the literature

Key Clinical Message

In contrast to intestinal balantidiasis, which is widespread throughout the world, urinary balantidiasis is uncommon. It often affects people with underlying diseases, and acute infections may be fatal. Even though urine is not typical for this parasite, specific morphologic characteristics can aid in accurate diagnosis.

Abstract

Balantidium coli is a ciliated protozoan which can infect intestinal system. Urinary balantidiasis is an extremely rare infection that may cause serious issues in patients with underlying diseases. Herein, we present a case of urinary balantidiasis in a patient with bladder cancer.

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.

Balantidiasis in humans: A systematic review and meta-analysis

Balantioides coli is a protozoan that infects different hosts species, including humans, with zoonotic transmission. The parasite, which lives in the large intestine and in other organs, can lead to serious infections that may culminate in death. Information about human balantidiasis is generally still very scanty. In view of the above, the purpose of this study was to analyze the epidemiological, clinical and laboratory characteristics of human balantidiasis based on a systematic review and meta-analysis. The scientific articles were retrieved from various databases and were subjected to descriptive analyses, chi-squared tests, and summarized on a forest plot and the heterogeneity index (I²). A total of 103 articles were eligible and included in this review. Out of these 103 articles, 75 were clinical case reports and 28 were epidemiological studies, indicating a frequency of 997 (3.98%) people potentially infected with B. coli. The publication dates of the analyzed articles ranged from 1910 to 2020, but the majority (68.9%) were published between 1998 and 2020. A considerable number of these articles were published in South America and Asia, mostly in Brazil and India, respectively. However, in Africa, Ethiopia, was observed the higher number of infected people (47.5%). A significant association (p < 0.05) was identified between proximity to pigs and positivity for B. coli, since more than 16% infected people were in proximity with pigs and/or their excreta. Infection by the protozoan was classified mainly as intestinal, and the predominant symptom was dysentery. Extraintestinal infections were found in 27 individuals, with colonization of the genitourinary tract frequently highlighted. Direct examination (17.2%), followed by an association of direct examination and sedimentation (45.7%), were the most commonly performed parasitological techniques, and the most frequently diagnosed form was trophozoites, corresponding to 22.5% of cases. The most common treatment for parasitized individuals (11.8%) was an association of tetracycline drugs with nitroimidazole derivatives. The articles retrieved, mainly epidemiological ones, used in meta-analysis showed high heterogeneity (I²> 50%, p < 0.05), impairing the retrieval and comparison of results. Some articles were found to provide incomplete information, making it difficult to retrieve and analyze variables. However, this review enabled us to compile and restate factors that appear to be associated with cases of human balantidiasis.

Prevalence and molecular identification of Balantioides coli isolates from pet guinea pigs in Central China

Balantioides coli is the only known zoonotic ciliate that can infect humans and is usually acquired from swine. It has, however, been reported in other mammals, including guinea pigs, where infection prevalence and molecular characterization are relatively unknown. In the present study, 32 guinea pigs from two different pet markets in Luoyang city of the Henan province in China were evaluated for ciliate-like trophozoites or cysts by direct fecal smear microscopy. Positive samples were further characterized using 18S rDNA and ITS1-5.8S rDNA-ITS2 sequence analysis. Microscopy indicated that ciliate-like cysts were observed in the fecal samples of several guinea pigs, were spherical in shape, and exhibited sizes of 40-65 μm in diameter. The average cyst-positive prevalence in guinea pigs was 62.5%. Sequence analysis indicated that the guinea pig-derived ciliate isolates belonged to B. coli and included two genetic variants (A and B), of which genetic variant A was more dominant among the guinea pig samples. To the best of our knowledge, the present study is the first molecular identification of B. coli in guinea pigs and provides some important information for investigating the molecular epidemiology of B. coli.