We admitted a 58-year-old patient with chief complaints of fever, losing weight, and cough with whitish-yellow sputum that started one month ago. Her symptoms gradually progressed, and she did not completely respond to outpatient treatment. We ordered the bronchoscopy according to abnormal laboratory tests, and CT scan findings. After further evaluation, the BAL specimen reported a negative fungal and bacterial infection in the samples. However, the microscopic examination revealed some live and oval flagellated lophomonas protozoa, hydatid cyst protoscoleces (the larval forms of the parasites), and M. tuberculosis. The positive anti-echinococcus antibodies were founded. Finally, the patient was treated with metronidazole, oral albendazole, and a combination M. tuberculosis regimen started.
Clinically significant pulmonary protozoan infections are rare but have been increasingly recognized in recent decades because of individual states of suppressed immunity. Various studies have declared the high prevalence of co-infection of M. tuberculosis and parasitic diseases such as E. granulosus and lophomonas. Furthermore, M. tuberculosis and parasitic diseases were the risk factors for each other. The study by Li X.,et al.2013, found that many factors possibly affect the co-infection of TB and parasitic diseases, such as socio-demographics (gender and age), underlying diseases, and living in co-endemic areas (higher prevalence of M. tuberculosis and parasitic infections). According to a study by Li R.,et al.2016, L. blattarum was considered an opportunistic infection in patients with kidney and liver allograft transplantation under corticosteroid therapy, HIV, E. granulosus and M. tuberculosis infection [1, 2, 4, 12,13,14].
In this study, we reported the co-infection of M. tuberculosis, lophomonas, and E. granulosus; the occurrence of these infections together is rare and has not been previously reported. In endemic areas such as Iran, the diagnosis of E. granulosus and M. tuberculosis infection can often be easily made by clinical findings, serological tests, and radiographic findings [1, 4, 7, 12].
It could be suspected that the patient first had E. granulosus or M. tuberculosis infection, and in the subsequent period, lophomonas as super infection was added to co-infections. Because lophomonas often occurs in immunocompromised patients, and M. tuberculosis or E. granulosus infection impairs the immune system, making individuals more susceptible to L. blattarum infections and reactivating latent infections. However, considering the patient’s symptoms presented acutely and two months prior to admission, the patient’s previous routine laboratory tests and inflammatory markers were normal. In addition, due to the positive E. granulosus-specific IgM and IgG, active tuberculosis, our patients were more likely to have co-infection M. tuberculosis and E. granulosus with lophomonas. The study by Kalani M., et al. 2022, mentioned that the prevalence of lophomonas infection was relatively high in patients with suspected tuberculosis due to similar clinical manifestations of this co-infection (1, 2,3,4, 11, 12).
L. blattarum, M. tuberculosis, and E. granulosus infections present with untypical and non-specific clinical manifestations, such as cough, sputum, sweating, weight loss, weakness, malaise, hemoptysis, and dyspnea. These infections often involve the respiratory tract system with the most likely form of airborne transmission and are similar in terms of clinical patterns and radiographic findings. Notably, these non-specific symptoms might obscure the diagnosis and treatment, and clinical symptoms cannot distinguish these infections from other diseases. Researchers believe these infections should be considered in patients with eosinophilia, severe respiratory infection, immunosuppression, and unsuccessful antimicrobial treatment [1,2,3,4,5,6,7,8,9,10,11,12,13,14].
These infections’ X-ray and CT scan findings revealed ground-glass opacity, patchy consolidation, patchy or streaky shadows, cystic lesions, abscesses, and pleural effusion. Using these findings makes it difficult to differentiate this co-infection from other common diseases with similar radiographic findings (such as pneumonia, bronchitis, cancer, or inflammation) [1, 3, 4, 9, 12].
A bronchoscopy biopsy smear, sputum smear, or BAL can be performed to detect L. blattarum, tuberculosis, and hydatid in patients. However, it is challenging to differentiate L.blattarum and ciliated epithelial cells based on morphology under a light microscope, which can lead to misdiagnosis [2,3,4,5,6,7]. The lung epithelial cells display cilia of uniform size with consistent movement, and a terminal bar is observed at the base of the cilia. These cells also exhibit a slightly slender shape. L. blattarum features two tufts of flagella of varying sizes located in the anterior region, demonstrating a wavy movement. No terminal bar is observed at the base of the flagella, and the parasite is nearly round. Additionally, the morphological characteristics of this parasite were examined using an electron microscope, confirming its presence. Microscopy-based diagnosis often lacks the necessary sensitivity and specificity. Consequently, molecular-based diagnosis (PCR method) was performed in this study to identify Lophomonas spp [15].
As M. tuberculosis and E. granulosus are common infections in this region, and the true mechanism of lophomonas transmission has not been clearly described, the management and diagnosis of these co-infections are essential in practice. Clinicians should consider this co-infection in differential diagnoses of patients with a chronic dust allergy, unresponsiveness to antibiotic therapy, and recurrent respiratory infections.
Our study had strengths. We reported an extremely rare case of M. tuberculosis, E. granulosus, and lophomonas co-infection in a patient. In addition, according to the patient’s present illness, clinical examination, and initial radiography findings, we initially isolated the patient with the suspicion of possible opportunistic infections. We gave the necessary warnings to all the people in close contact with her and examined them for possible infections. Moreover, we prevented the patient from suffering from complications caused by each mentioned pathogen with timely diagnosis and appropriate treatment. We also faced limitations. We had to send the patient’s sample to another center for a definitive diagnosis of lophomonasis, which was time-consuming.
