Human urinary myiasis due to larvae of Telmatoscopus (Clogmia) Albipunctata in Morocco: A case report

Abstract

This is the first case of urinary myiasis in the Morocco region caused by Clogmia albipunctata. Also known as Telmatoscopus albipunctata, is a fly species in the Psychodidae family. These flies thrive in unsanitary environments like bathrooms and sewers. Transmission occurs when flies lay eggs on moist surfaces such as urogenital discharge. The larvae hatch and can traverse the urethra, entering the bladder. Clogmia albipunctata larvae and adults decompose organic matter and pose health risks as vectors of pathogens and allergens. In our case, larvae were discharged through urine by a 46-year-old female cleaner from a low socioeconomic background who presented with intermittent emission of worms in her urine. She had mild hypogastric tenderness and a history of lower urinary tract symptoms without fever. Initially misdiagnosed with cystitis, her symptoms persisted, leading to the discovery of small, mobile vermiform organisms in her urine. Living in fly-infested conditions, she had no recent travel or medical history. Urine analysis confirmed the presence of Clogmia albipunctata larvae, diagnosing urinary myiasis. Treated with ivermectin and hydration, her symptoms resolved within a week. A follow-up cystoscopy showed no larvae, confirming a complete cure.

Introduction

Human myiasis is a pathological entity defined by the infestation of the tissues of a living individual by the larval stages of Diptera, mainly flies. ¹ This condition is characterized by the development of larvae that feed on the host and occupy its body habitat, with significant clinical and health consequences. ² The sites most frequently affected include the skin, oral cavity, eyes, nasopharyngeal region, intestine, and urogenital region. ³ Urinary myiasis generally occurs in people with poor genitourinary hygiene, from low socioeconomic backgrounds, who are immunocompromised, or who live in environments where water sources are poorly sanitized. ⁴

Here, we report a case of human urinary myiasis caused by Clogmia albipunctata larvae, which, to our knowledge, represents the first case reported in the Moroccan region.

Case presentation

A 46-year-old female patient, from a low socioeconomic background, a cleaner by profession, married and mother of two children, living in the town of Bouskoura in Casablanca, Morocco, presented to the urology department with intermittent emission of worms in the urine.

In the clinical evaluation, the patient appeared to be in good general condition. She was hemodynamically and respiratory stable, and apyretic. Abdominal palpation revealed mild hypogastric tenderness. Analysis of the urine sample revealed the presence of small vermiform organisms (Figure 1). She denied any medical or surgical history and no recent travel history. From a gynecological point of view, the patient was Gravida 2, Para 2 (G2P2), with no notable pathological genital history and no recurrent genital infections. However, she did not have regular gynecological check-ups.

Figure 1.

Macroscopic appearance of mature Clogmia albipunctatus larvae. (a) The whole larva with an elongated, hairy, segmented body. (b) Larvae at different stages of maturity (left: mature, right: immature).

The symptoms began 2 months ago with a gradual onset of irritative lower urinary tract symptoms (LUTS), including pollakiuria and dysuria, albeit in the absence of fever. Upon consultation, a general practitioner diagnosed the patient with simple cystitis and administered treatment accordingly, which failed to yield clinical improvement. Subsequently, the patient developed pruritus in the periurethral and genital regions, coinciding with intermittent expulsion of small, blackish, mobile vermiform organisms in the urine. The patient reported no history of recurrent urinary tract infections or any specific genitourinary pathology. However, her living conditions were suboptimal, characterized by the use of fly-infested septic tank latrines. She also denied engaging in sexual activity, any contact with animals, or suffering insect bites.

Abdominal and pelvic ultrasound revealed no abnormalities, and the bladder exhibited a thin wall without endoluminal abnormalities. A comprehensive urinalysis and direct smear examination of the feces were performed. Morphological evaluation of the larvae in two different urine samples identified larvae of variable sizes belonging to the species C. albipunctata (Diptera: Psychodidae) (Figure 2), confirming the diagnosis of urinary myiasis. Fecal analyses were normal. Subsequent urine analyses and cultures, involving both the larvae and inter-larval stages, yielded negative results. DNA sequencing was not performed.

Figure 2.

Microscopic appearance of mature Clogmia albipunctata larvae. (a) The triangular head, with two tiny hairy antennae. (b) The abdominal segments, covered with long dark filiform setae directed backward. (c) The two respiratory tubes extending along the body. (d) The last abdominal segment, which ends in two separate respiratory tubules bearing posterior spiracles at the apex, which are protected by dorsal and ventral bristle brushes.

Treatment was initiated with a double oral dose of ivermectin at 200 μg/kg, combined with ample oral hydration. The LUTS disappeared 1 week after treatment. The patient reported no subsequent expulsion of worms in the urine. A cystoscopy performed 1 month later showed no signs of larvae and non-inflamed bladder mucosa. After follow-up, the patient was deemed completely cured.

Discussion

C. albipunctata, or Telmatoscopus albipunctata, is a species of Diptera belonging to the Psychodidae family (sewer flies). Both larvae and adults play an essential role in the decomposition of organic matter. Although these flies are non-biting and do not feed on blood, they present potential risks to human health as mechanical vectors of various pathogens, including bacteria and protozoa. ⁵ They can also cause allergic reactions in some people, including respiratory problems such as allergic rhinitis and asthma. ⁶

In addition, C. albipunctata has been reported to cause myiasis in humans. It can manifest as obligatory, facultative, or accidental for the host. ⁷ Psychodidae are commonly found in human habitats, such as bathrooms, kitchens, sewers, and poorly maintained drains, thereby facilitating infestation due to various well-defined risk factors. ⁵ These factors include poor sanitation and hygiene, as well as unfavorable living conditions like overcrowding and inadequate ventilation, which elevate the risk of infestation. Individual health issues, such as immunosuppression, limited mobility, and ulcerative lesions, further heighten susceptibility to this parasitic condition.^1,4,8 Physiological characteristics of the female urogenital system, such as a shorter urethra, may also contribute to the susceptibility of women to urinary myiasis. ⁹ Furthermore, practices such as urinating in unsanitary toilets or sleeping uncovered in hot weather, particularly among women, can promote the onset of this infestation. Urogenital discharge or moist pubic areas can attract flies to lay eggs around the urethral meatus and external genitalia. The hatched larvae can traverse the urethra and enter the bladder, ⁵ leading to urethral discharge, irritative lower urinary tract disorders, and hematuria. Pathogenicity ensues from the inflammatory granuloma and toxins secreted by the larvae, hindering healing. Progressive and continuous necrosis of the bladder wall may ensue, concomitant with the growth and invasion of the larvae. ⁹

Diagnosis of urinary myiasis relies on the microscopic identification of larvae in the urine. There is no standard treatment for managing urinary myiasis. Oral administration of an antihelminthic, ivermectin, appears to be appropriate. ⁷ However, sporadic cases of spontaneous recovery without treatment have been documented in the medical literature. ¹⁰ It could be conjectured that this spontaneous recovery is due to the interruption of the parasite cycle. As accidental hosts, humans effectively disrupt the reproductive cycle of fly larvae by eliminating them via the urinary tract. Unlike other parasites, larvae of urinary myiasis do not reproduce in the human host; only the reproductive cycle of the adult fly can sustain reinfestation.

Our case presents a limitation. Due to its high cost and unavailability, DNA sequencing was not performed. Although this would have had no impact on therapeutic management, the analysis would have been of definite epidemiological interest.

Conclusion

Although urinary myiasis is rare, it occurs worldwide. Effective fly management requires reducing food sources and implementing rigorous hygiene measures. Key preventive strategies include eliminating food waste, regularly cleaning breeding areas, and using specialized traps. In addition, insecticides, biological control methods, and professional pest management services can be considered to enhance control efforts.