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Year : 2022  |  Volume : 9  |  Issue : 1  |  Page : 120-122

Diarrhea associated with Pentatrichomonas hominis in an infant: A case report

Department of Microbiology, Dr. D.Y. Patil Medical College, Hospital & Research Center, Dr. D Y Patil Vidyapeeth, Pune, Maharashtra, India

Date of Submission24-Dec-2021
Date of Acceptance22-Feb-2022
Date of Web Publication23-Mar-2022

Correspondence Address:
Dr. Sameena Khan
Department of Microbiology, Dr. D Y Patil Medical College, Hospital & Research Center, Dr. D.Y. Patil Vidyapeeth, Pimpri Colony, Pune 411018, Maharashtra.
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/mgmj.mgmj_108_21

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Pentatrichomonas hominis is a flagellated protozoan parasite that resides in the digestive tract of humans and is generally nonpathogenic. Although parasites of diarrheal etiology are widespread, neonatal infection with P. hominis is an uncommon incident. This case report depicts an instance of active P. hominis in an 8-month-old child with complaints of fever, vomiting, and loose stools. Stool examination was done with saline and iodine wet mount that showed motile trophozoites of P. hominis with a jerky movement. Treatment with metronidazole was effective as no parasite was found on repeated stool examinations. Pentatrichomonas hominis should be recognized as a cause of diarrhea in neonates, despite being rare.

Keywords: Infant, metronidazole, Trichomonas hominis

How to cite this article:
Khan S, Gandham NR, Das NK, Patil RA, Mirza S, Kannuri S. Diarrhea associated with Pentatrichomonas hominis in an infant: A case report. MGM J Med Sci 2022;9:120-2

How to cite this URL:
Khan S, Gandham NR, Das NK, Patil RA, Mirza S, Kannuri S. Diarrhea associated with Pentatrichomonas hominis in an infant: A case report. MGM J Med Sci [serial online] 2022 [cited 2022 May 17];9:120-2. Available from: http://www.mgmjms.com/text.asp?2022/9/1/120/340578

  Introduction Top

Pentatrichomonas hominis, formerly known as Trichomonas hominis, is a flagellated protozoan parasite that inhabits the intestines of humans and animals. Previously recognized as a commensal, this protozoan parasite has been identified as a potential causative agent of diarrhea in adults and the young population. Therefore, the possibility of infection caused by T. hominis cannot be excluded especially in developing countries.[1]

The trichomonads are composed of a group of flagellated parasites that include four species that infect humans. They are Dientamoeba fragilis, P. hominis, T. vaginalis, and T. tenax. Dientamoeba fragilis has been identified in stool samples of patients suffering from gastrointestinal issues and is related to irritable bowel syndrome. Trichomonas tenax has been found as a commensal in the human oral cavity.[2],[3]Trichomonas vaginalis, which colonizes the human vagina, is responsible for trichomoniasis, a common sexually transmitted infection (STI) associated with adverse pregnancy outcomes. Several reports relate P. hominis as a possible cause of diarrhea, particularly in children.[4]Pentatrichomonas hominis are recognized by the presence of three to five anterior flagella and a single recurrent flagellum.[5]

  Case report Top

An 8-month-old male child presented to the pediatric outpatient department with a 4-day history of intermittent fever and watery diarrhea. The infant was reported to have had about 10 episodes of watery stools over the previous 24 h and 3 episodes of vomiting. The child refused to eat and drink and had been crying a lot.

On physical examination, the infant was alert but irritable. The temperature was (100°F), heart rate was between 150 and 170 beats/min, and respiratory rate was between 40 and 80 breaths/min. Laboratory investigations showed hemoglobin of 12 g/dL and C-reactive protein(CRP) was 14.10 mg/dL. The results of other laboratory tests such as complete blood count (CBC) and chemistry all were negative. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were raised. The urine analysis and culture were normal and negative, respectively. The patient was admitted and empirically started on injectables of Ondansetron, Pantoprazole, oral Zinc syrup, and suspension of Bacillus clausii spores. Stool samples were collected in a wide-mouthed, clean, leak-proof container without contamination and sent for routine microscopy and parasitological examination. Samples were first examined macroscopically and then microscopically as part of routine parasitological examinations. On naked eye examination, a sample was yellowish in color, watery inconsistency, and with a foul odor. No red blood cells (RBCs), mucus, or any larva or adult worm were seen. Microscopic examination of stool wet mount in normal saline and Lugol’s iodine showed many pyriform-shaped motile trophozoites [Figure 1]A and B]. The motility was rolling and jerky. Few pus cells and crystals were also seen under stool wet mount examination.
Figure 1: (A) Black arrow: Trophozoites of Pentatrichomonas hominis on stool saline mount (40×). (B) White arrow: Trophozoites of Pentatrichomonas hominis on stool iodine mount (40×)

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Three additional samples were obtained to rule out misidentification which showed similar results. As the trophozoite nuclei were not seen in the wet mount we stained smears with Giemsa and modified trichrome stain after methanol fixation. Numerous pear-shaped trophozoites with a single nucleus, and the undulating membrane extending through the entire length of the body. The undulating membrane and flagella of P. hominis produce this type of motion, which helped in its identification. Similar findings were reported from all the other three stool samples collected. Stool culture was done to rule out bacterial causes of diarrhea, and no pathogens were found. The patient was treated with injection Metronidazole (30 mg/kg/day) for 3 days and diarrhea subsided. Repeat wet mount preparation of the stool sample was examined and did not show the presence of any parasite. Hence, our patient was successfully treated and discharged in stable condition after 7 days of admission.

  Discussion Top

The case described here is the first documented case of infection caused by P. hominis in an infant in our part of the globe. Diarrhea is a common and serious disease that affects approximately 25% of children all around the world. In recent years, Pentatrichomonas hominis has become increasingly recognized as an important enteric pathogen in immunocompromised that infects a wide range of hosts. It is a commensal in the human caecum and large intestines that undergo multiplication under favorable conditions and can cause diarrhea.[1 Meloni et al.[2] identified P. hominis as a cause of diarrhea in two children: one with irritable bowel syndrome and the other with abdominal pain. Compaoré et al.[3] found P. hominis in the stool sample of a rheumatoid arthritis patient who was treated with adalimumab (immunosuppressive agent) suffering from gastrointestinal symptoms. Infections with P. hominis are more common in children than in adults mainly due to the fecal-oral transmission route of the trichomonad. Prevalence of 1.1% has been reported for children in Morocco.[6] Information regarding the parasite being susceptible to metronidazole is not many but our patient was completely cured by this drug.[2],[3] It draws attention to the possibility of encountering diarrhea in an infant due to P. hominis and being appropriately treated.

  Conclusion Top

The flagellate P. hominis is often identified in human diarrheic stools. Because of the fecal-oral transmission route, infection with T. hominis is more frequently reported in children than in adults. It can be a major health concern in many countries around the world, and hence stool samples should be screened carefully. Detailed research, prompt diagnosis, and routine screening of stools, particularly in immunocompromised patients can be helpful.

Ethical policy and institutional review board statement

Institutional Ethics Sub-Committee of Dr. D.Y. Patil Medical College Hospital and Research Center, Pune, Maharashtra, India has reviewed the case report and found involving unusual findings increasing awareness of such observations among faculty and students and waiver will not adversely affect the right and welfare of the concerned patient. Hence, a waiver has been granted for this Case Report vide letter no. I.E.S.C./W/02/2022 dated February 10, 2022.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Maritz JM, Land KM, Carlton JM, Hirt RP. What is the importance of zoonotic trichomonads for human health? Trends Parasitol 2014;30:333-41.  Back to cited text no. 1
Meloni D, Mantini C, Goustille J, Desoubeaux G, Maakaroun-Vermesse Z, Chandenier J, et al. Molecular identification of Pentatrichomonas hominis in two patients with gastrointestinal symptoms. J Clin Pathol 2011;64:933-5.  Back to cited text no. 2
Compaoré C, Kemta Lekpa F, Nebie L, Niamba P, Niakara A. Pentatrichomonas hominis infection in rheumatoid arthritis treated with adalimumab. Rheumatology (Oxford) 2013;52:1534-5.  Back to cited text no. 3
Wenrich DH. Morphology of the intestinal trichomonad flagellates in man and of similar forms in monkeys, cats, dogs, and rats. J Morphol 1944;74:189-211.  Back to cited text no. 4
Felleisen RS. Host-parasite interaction in bovine infection with tritrichomonas foetus. Microbes Infect 1999;1:807-16.  Back to cited text no. 5
El-Fadeli S, Bouhouch R, Lahrouni M, Chabaa L, Asmama S, Fdil N, et al. The prevalence of intestinal parasites in school children in a rural region of Marrakech-Morocco. Int J Innov Sci Res 2015;19:229-34.  Back to cited text no. 6


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