Lophomonas Blattarum Research Articles

Diagnosis of pulmonary lophomoniasis infection in patient with systemic lupus erythematosus; A case report and literature review.

Over the past 30 years, there has been an increasing number of documented human infections associated with the protozoan Lophomonas, specifically Lophomonas blattarum, which is considered a relatively rare infection. These infections are primarily associated with states of immune suppression, including those resulting from corticosteroid therapy. We report a 61-year-old female patient with a 20-year medical history of Systemic lupus erythematosus (SLE) who was admitted due to persistent respiratory symptoms that were unresponsive to treatment. The patient was receiving immunosuppressive therapy for SLE. Upon hospitalization, computed tomography of the lungs revealed the presence of centrilobular nodules exhibiting tree-in-bud patterns, as well as bronchiectasis, predominantly in the middle and lower lobes. Subsequently, the patient underwent bronchoscopy, during which a BAL sample was obtained. Microscopic analysis of the sample indicated the presence of L. blattarum. Clinicians often focus on the primary symptoms of SLE, but they must also consider the risk of severe respiratory complications like lophomoniasis. This condition is critical to address in the management of SLE patients, who are immunosuppressed due to the disease's nature and its treatment.

Neumonía atípica por Lophomonas blattarum en un paciente inmunocomprometido: reporte de un caso

Respiratory infection by Lophomonas Blattarum is a rare opportunistic pathology, however, immunocompromised individuals are susceptible to contract this infection. The following is a case of Lophomonas Blattarum pneumonia in a 44-year-old patient with Human Immunodeficiency Virus (HIV), who was admitted to the Regional Military Hospital of Puebla with respiratory distress, non-productive cough, chest pain and fever; during his initial approach a presumptive positive HIV 1-2 Ac. test was detected. Imaging studies showed findings characteristic of pneumonia caused by atypical microorganisms, so empirical treatment with cephalosporin, macrolide, triazoles and sulfonamide was decided. The bronchial secretion culture revealed a multiflagellate protozoan parasite (L. Blattarum), so pharmacological management was started with metronidazole with an impregnation dose of 1500 milligrams, continuing with 500 milligrams every 8 hours for 2 weeks, which resulted in improvement of symptoms and respiratory function. She concluded her stay at the Regional Hospital of Puebla, for follow-up and confirmation of HIV at the third level of care. Finally, despite antibiotic treatment, immunosuppressed patients, together with any opportunistic infection, mortality is present in more than 80%.

Imaging patterns of Lophomonas blattarum infection in the respiratory tract: a registry-based analysis

BackgroundLophomonas blattarum is an emerging protozoan that mostly infects the lower respiratory tract and causes pulmonary lophomoniasis. Radiologic findings in patients with pulmonary lophomoniasis have yet to be studied. Thus, we conducted a registry-based clinical investigation to evaluate the radiologic findings of lophomoniasis.MethodsIn this cross-sectional study, 34 Lophomonas positive patients were enrolled. Demographic data, relevant characteristics, and radiologic findings of the patients were recorded and analyzed.ResultsThirty-four (male = 18, female = 16) patients with an average age of 52.21 ± 20.48 years old were examined. Radiological findings such as Alveolar consolidation (26.5%), Ground glass opacity (5.9%), Centrilobular nodules (23.5%), Tree -in- bud (38.2%), Cavitation (23.5%), Pleural effusion (23.5%), Interstitial opacity (8.8%), Lymphadenopathy (23.5%), Bronchocele (5.9%), Bronchiectasis (29.4%), Nodules (8.8%) and Mass (11.8%) were obtained, that the frequency of all radiological findings was less than 50%.ConclusionIn this study, the most common radiological findings in patients with lophomoniasis were tree-in-bud nodules, alveolar consolidation, bronchiectasis, and centrilobular nodules which were mostly seen in the right lung and its middle and lower lobes. Given that the radiologic findings of this disease are unknown, it can be considered in differential diagnosis.

Lophomonas as a respiratory pathogen-jumping the gun.

Human infections with the protozoan Lophomonas have been increasingly reported in the medical literature over the past three decades. Initial reports were based on microscopic identification of the purported pathogen in respiratory specimens. Later, a polymerase chain reaction (PCR) was developed to detect Lophomonas blattarum, following which there has been a significant increase in reports. In this minireview, we thoroughly examine the published reports of Lophomonas infection to evaluate its potential role as a human pathogen. We examined the published images and videos of purported Lophomonas, compared its morphology and motility characteristics with host bronchial ciliated epithelial cells and true L. blattarum derived from cockroaches, analyzed the published PCR that is being used for its diagnosis, and reviewed the clinical data of patients reported in the English and Chinese literature. From our analysis, we conclude that the images and videos from human specimens do not represent true Lophomonas and are predominantly misidentified ciliated epithelial cells. Additionally, we note that there is insufficient clinical evidence to attribute the cases to Lophomonas infection, as the clinical manifestations are non-specific, possibly caused by other infections and comorbidities, and there is no associated tissue pathology attributable to Lophomonas. Finally, our analysis reveals that the published PCR is not specific to Lophomonas and can amplify DNA from commensal trichomonads. Based on this thorough review, we emphasize the need for rigorous scientific scrutiny before a microorganism is acknowledged as a novel human pathogen and discuss the potential harms of misdiagnoses for patient care and scientific literature.

True molecular phylogenetic position of the cockroach gut commensal Lophomonas blattarum (Lophomonadida, Parabasalia).

Lophomonas blattarum is a facultative commensal gut dweller of common pest cockroaches. Its cells are roughly spherical in shape with an apical tuft of ~50 flagella. Controversially, it has been implicated in human respiratory infections based on light microscopic observations of similarly shaped cells in sputum or bronchoalveolar lavage fluid. Here, we have sequenced the 18S rRNA gene of L. blattarum and its sole congener, Lophomonas striata, isolated from cockroaches. Both species branch in a fully supported clade with Trichonymphida, consistent with a previous study of L. striata, but not consistent with sequences from human samples attributed to L. blattarum.

Lophomonas blattarum-like organism in bronchoalveolar lavage from a pneumonia patient: current diagnostic scheme and polymerase chain reaction can lead to false-positive results.

Lophomonas blattarum is an anaerobic protozoan living in the intestine of cockroaches and house dust mites, with ultramicroscopic characteristics such as the presence of a parabasal body, axial filament, and absence of mitochondria. More than 200 cases of Lophomonas infection of the respiratory tract have been reported worldwide. However, the current diagnosis of such infection depends only on light microscopic morphological findings from respiratory secretions. In this study, we attempted to provide more robust evidence of protozoal infection in an immunocompromised patient with atypical pneumonia, positive for Lophomonas-like protozoal cell forms. A direct search of bronchoalveolar lavage fluid via polymerase chain reaction (PCR), transmission electron microscopy (TEM), and metagenomic next-generation sequencing did not prove the presence of protozoal infection. PCR results were not validated with sufficient rigor, while de novo assembly and taxonomic classification results did not confirm the presence of an unidentified pathogen. The TEM results implied that such protozoal forms in light microscopy are actually non-detached ciliated epithelial cells. After ruling out infectious causes, the patient's final diagnosis was drug-induced pneumonitis. These findings underscore the lack of validation in the previously utilized diagnostic methods, and more evidence in the presence of L. blattarum is required to further prove its pathogenicity.

Lophomonas Blattarum Respiratory Infection in an Immunocompromised Patient: A Case Report from Dubai

Lophomonas Blattarum Respiratory Infection in an Immunocompromised Patient: A Case Report from Dubai

An emerging new respiratory pathogen, Lophomonas blattarum, found in bronchoalveolar lavage in an immunodeficient patient with asthma

Infections with unusual organisms are frequently found in patients with primary and acquired immunodeficiency. It is estimated that 1 in 1200 individuals in the United States have a diagnosis of primary immunodeficiency, with common variable immunodeficiency (CVID) accounting for approximately 35% of the cases. 1 Boyle JM Buckley RH. Population prevalence of diagnosed primary immunodeficiency diseases in the United States. J Clin Immunol. 2007; 27: 497-502 Crossref PubMed Scopus (317) Google Scholar CVID is a heterogeneous disorder that is primarily a defect of the humoral immune system, although approximately 50% of patients have T cell defects as well. Patients with CVID have increased susceptibility to infections, particularly of the upper and lower respiratory tract, and increased incidence of autoimmune diseases and neoplasms. 2 Bonilla FA Kahn DA Ballas ZK Chinen J Frank MM Hsu JT et al. Practice parameter for the diagnosis and management of primary immunodeficiency. J Allergy Clin Immunol. 2015; 136 (1186-1205.e1-e78) Abstract Full Text Full Text PDF PubMed Scopus (394) Google Scholar Common pathogens causing respiratory tract infections in CVID include Streptococcus pneumoniae, Haemophilus influenza, and Staphylococcus aureus.2 Bonilla FA Kahn DA Ballas ZK Chinen J Frank MM Hsu JT et al. Practice parameter for the diagnosis and management of primary immunodeficiency. J Allergy Clin Immunol. 2015; 136 (1186-1205.e1-e78) Abstract Full Text Full Text PDF PubMed Scopus (394) Google Scholar Although parasitic infections can occur, the most often described is Giardia infection of the gastrointestinal tract. 2 Bonilla FA Kahn DA Ballas ZK Chinen J Frank MM Hsu JT et al. Practice parameter for the diagnosis and management of primary immunodeficiency. J Allergy Clin Immunol. 2015; 136 (1186-1205.e1-e78) Abstract Full Text Full Text PDF PubMed Scopus (394) Google Scholar Infections with other parasites particularly of the respiratory tract have rarely been described. Lophomonas blattarum is a flagellated protozoa found in the gut of cockroaches and termites which has been found to cause rare bronchopulmonary infections, although there are no published cases in the United States to date. 3 Martinez-Girón R Cornelis van Woerden H. Lophomonas blattarum and bronchopulmonary disease. J Med Microbiol. 2013; 62: 1641-1648 Crossref Scopus (35) Google Scholar ,4 Chaudhury A Parija SC. Lophomonas blattarum: a new flagellate causing respiratory tract infections. Trop Parasitol. 2020; 10: 7-11 Google Scholar The most often reported symptoms of L blattarum infection are fever and productive cough. The infection is usually responsive to treatment with metronidazole. 3 Martinez-Girón R Cornelis van Woerden H. Lophomonas blattarum and bronchopulmonary disease. J Med Microbiol. 2013; 62: 1641-1648 Crossref Scopus (35) Google Scholar ,4 Chaudhury A Parija SC. Lophomonas blattarum: a new flagellate causing respiratory tract infections. Trop Parasitol. 2020; 10: 7-11 Google Scholar

Detection of Lophomonas blattarum (Order: Hypermastigida) from Iranian Patients with Allergic Rhinitis.

Allergic rhinitis (AR) is one of the most common allergic diseases triggered by indoor and outdoor allergens. Certain arthropods, such as mites and cockroaches, contain protozoa like Lophomonas blattarum in their intestines to help with digestion that may have some role in AR. We aimed to determine the frequency of L. blattarum in nasal smears of patients with AR in comparison with healthy controls. In this prospective cross-sectional study (March 2015-March 2016), 36 patients with a clinical presentation of AR (with a positive prick test including mites) and 34 normal controls were included at ear, nose, and throat (ENT) clinic at Imam Reza Hospital of Mashhad, Iran. Nasal secretions were evaluated to examine presence of L. blattarum in the patients and control group by direct method. Diagnosis of L. blattarum was based on microscopic observation both on direct smear and Giemsa stained specimens. Patients with AR had a higher frequency of L. blattarum in their nasal smears than the control group (25% vs. 2.9%) (P=0.001). We found L. blattarum more frequently in the nasal secretion of AR patients compared with healthy subjects; this protozoon may have some role in this condition. However, the relationship between L. blattarum and AR requires further studies to allow a greater understanding.

Effective Treatment of Chronic Cough with Tinidazole as the Newest Antiprotozoa against Lophomonas blattarum.

Chronic cough is a common problem in the setting of family physicians. Recently, Lophomonas blattarum was considered a cause of respiratory symptoms in children and adults. This study is aimed at determining the effect of antiprotozoal treatment of Lophomonas in patients with a chronic cough in Mashhad during 2020-2021. This study was a randomized clinical trial. In this study, 60 patients with chronic cough and unremarkable imaging findings, who were unresponsive to three steps of standard treatment, were randomly assigned to the treatment, with 2 weeks of tinidazole and placebo. The tinidazole and placebo were prepared in a completely identical shape, and a random assignment was performed by a third party. The primary outcome was a complete resolution of cough. A follow-up of treatment was performed. Data were analyzed using the SPSS software version 25. The basic demographic results showed no significant differences of sex and age between two groups. The results of this study showed a complete resolution of all respiratory symptoms in 40% (12), a complete improvement of cough in 40% (12), and a complete resolution of dyspnea in 50% (10) of the tinidazole group. The remaining showed significant improvement in the severity of cough and dyspnea. Postnasal drip, sputum, body temperature, and airway hyperresponsiveness were improved significantly. After tinidazole treatment, laboratory assessment of bronchial lavage and sputum revealed that 86 percent of smears were converted to negative. Tinidazole effectively resolved the chronic cough and most of the respiratory symptoms. Lophomonas blattarum is a potential mechanism for chronic cough.

Fiberoptic Bronchoscopic Findings in Patients Suffering from Emerging Pulmonary Lophomoniasis: A First Registry-Based Clinical Study

Background Lophomonas blattarum is an emerging protozoan agent that mainly infects the lower respiratory system, causing pulmonary lophomoniasis. The bronchoscopic findings in patients with pulmonary lophomoniasis have not been investigated yet. Accordingly, we assess the bronchoscopic findings of lophomoniasis in patients suffering from pulmonary lophomoniasis through a registry-based clinical study. Methods In this retrospective study, of 480 patient candidates for bronchoscopy, 50 Lophomonas-positive patients were enrolled. Demographic data, relevant characteristics, and bronchoscopy findings of the patients were recorded and analyzed. Results Overall, 50 (male = 32, female = 18) patients with an average age of 61.8 ± 13.3 years were examined. Nineteen patients (38%) had normal bronchoscopic findings, and 31 patients (62%) had abnormal bronchoscopic findings. According to the severity index, most (52%) of patients had mild severity, followed by moderate (30%) and severe (18%) cases. The highest involvement was in the right lung bronchus (46%), and the lowest was in the carina (8%). Furthermore, purulent and mucosal secretions in the right and left lung bronchus were the most abnormalities found in different anatomical locations. Conclusion For the first time, the current study demonstrated that pulmonary lophomoniasis does not have pathognomonic bronchoscopic findings. However, each suspected patient must be checked for lophomoniasis, even with normal bronchoscopic findings, particularly in endemic areas.

Lower Respiratory Tract Infection due to Lophomonas blattarum : A Report of Two Cases and a Review

Lower Respiratory Tract Infection due to Lophomonas blattarum : A Report of Two Cases and a Review

Molecular Evidence of Emerged Pulmonary Lophomoniasis due to Lophomonas blattarum among Hospitalized Patients in Southwestern Iran: A National Registry-Based Study.

Objectives Lophomonas protozoan is an emerging pathogen transmitted through arthropods such as cockroaches. Lophomoniasis is still a mysterious disease with many unknown epidemiological aspects. The current study aimed to determine the prevalence of lophomoniasis among patients who were hospitalized in Hajar Hospital, Shahrekord, southwestern Iran, using a conventional PCR technique. Methods In this retrospective study, 132 frozen bronchoalveolar lavage fluid (BALF) specimens from patients with respiratory disorders hospitalized in Hajar Hospital, Shahrekord district, southwestern Iran, were analyzed during 2020-2021. Samples are referred to the Iranian National Registry Center for Lophomoniasis (INRCL), Mazandaran Province, Northern Iran, for detecting Lophomonas spp. infection by a conventionally small subunit ribosomal RNA (SSU rRNA) PCR test. Results A total of 132 frozen BALF specimens were examined, 36 (27.3%) tested Lophomonas spp. positive using the conventional PCR technique. Also, based on sequencing data and blast analysis, the presence of L. blattarum species was confirmed. The average age of Lophomonas spp.‐ positive patients was 67.02 ± 15.14 years. Out of the 36 positive subjects, 63.9% were male and 36.1% female. Male and Lophomonas infection had a significant correlation (p=0.001). Our findings revealed that L. blattarum infected nonsmokers more than smokers (p=0.001). The most common underlying disease was also bronchitis Conclusion Our results showed, for the first time, that pulmonary lophomoniasis caused by L. blattarum is a common and emerging disease in the study area, southwestern Iran. Furthermore, our findings support the use of the PCR test to detect Lophomonas infection in archived frozen clinical samples.

Diagnosis of Lophomonas blattarum in bronchoalveolar lavage samples

Lophomonas blattarum is a multi-flagellate protozoan which causes bronchopulmonary infection in human. As the culture and molecular diagnosis of Lophomonas blattarum have not yet been developed, direct slide examination from Bronchoalveolar lavage (BAL) or sputum is the best method for diagnosis of Lophomonas with morphological features. In the present study, in order to achieve quick and easy identification of Lophomonas, the sensitivity of different staining techniques has been investigated in comparison with the direct wet slide as the gold standard. Giemsa, Trichrome, and Papanicolaou stained-slides have been examined in patients who had lophomoniasis. Material &Methods BAL samples of patients suspected to lophomoniasis were collected. After confirmation of Lophomonas blattarum by observation in the direct test, the slides were prepared using Geimsa, Trichrome, and Papanicolaou staining for each patient. Results Among 158 BAL specimens sent to Imam Reza hospital lab, 50 samples were positive by direct microscopic examination which was stained by Giemsa, Trichrome, and Papanicolaou techniques. The highest sensitivity was seen for Papanicolaou staining with 16% and then Geimsa and Trichrome staining with 12% and 8%, respectively. Conclusion The results of this study show the Papanicolaou staining method had the best sensitivity compared to Giemsa, Trichrome stained-slides for differential diagnosis of this protozoan from epithelial cells.

Morphological and Molecular Identification of Emerged Lophomonas blattarum Infection in Mazandaran Province, Northern Iran: First Registry-Based Study.

In the last decade, several cases of bronchopulmonary lophomoniasis (BPL) have been recorded. Little information is available about epidemiological aspects on Lophomonas infection among BPL patients. The present study was aimed to investigate the prevalence of Lophomonas spp. infection in patients who were referred to the Iranian National Registry Center for Lophomoniasis (INRCL), using morphological and molecular tests. We examined patients enrolled in the INRCL from 2017 to 2019 at the Mazandaran University of Medical Sciences, northern Iran. All bronchoalveolar lavage fluid (BALF) and two nasal discharges of the patients were examined by both microscopic and small-subunit ribosomal RNA (SSU rRNA) PCR methods. To confirm the species of Lophomonas, two positive samples were sequenced. In this study, 321 specimens (including 319 BALF and 2 nasal discharges) were microscopically examined. Lophomonas spp. was found in 45(14%) (n = 44 BAL; n = 1 nasal discharge). The mean age of infected patients was 54.9 ± 17.1years. The following morphological characteristics were observed in both fresh and Papanicolaou-stained smears to identify Lophomonas spp. All microscopically positive specimens were confirmed with genus-specific PCR technique. The obtained sequences were deposited in Gen Bank under the accession numbers (MN243135-36). The BLAST analysis of our two sequences with the only available sequence in the Gen Bank of the Thailand strain of L. blattarum, showed identity of 99-100% and 98.51%, respectively. To the best of our knowledge, this is the first registry-based study regarding lophomoniasis worldwide. According to our study, the conventional PCR test is an available and reliable tool for confirming the Lophomonas parasite in clinical samples. Moreover, the results confirmed that L. blattarum is circulating at least in our region.

Neumonía por Lophomonas spp. a propósito de un caso

Lophomonas es un género de protozoos flagelados que contiene dos especies, Lophomonas striata y Lophomonas blattarum. Ambas son consideras endocomensales provenientes del tracto intestinal de artrópodos tales como termitas y cucarachas. Aunque Lophomonas striata no se considera importante en salud pública, Lophomonas blattarum es el agente causal de una infección respiratoria llamada lofomoniasis que afecta particularmente a individuos inmunocomprometidos (VIH/sida), trasplantados, neoplasias, corticoterapias a su vez pacientes asmáticos, ya sean estos niños y adultos. Se presenta el caso clínico de un hombre de 23 años atendido en el Hospital de Infectología Dr. José Daniel Rodríguez Maridueña, quien acude por debilidad generalizada, pérdida de peso, acompañado de alza térmica de tres meses de evolución. En el estudio microbiológico se evidenció Lophomonas spp., microorganismo poco frecuente en presentaciones clínicas.
 

Study of Lophomonas blattarum Infection in Kidney Transplant Patients in Mashhad City, Iran.

Background Lophomonas blattarum is a flagellate protozoan which is known as an emerging parasite in the human respiratory system. Organ transplant recipients are considered as immunocompromised patients due to prescription of immunosuppressive drugs. This group of patients is susceptible to opportunistic infection as well as lophomoniasis. This study aims to investigate the prevalence and clinical manifestation of pulmonary infections caused by L. blattarum in kidney transplant recipients. Methods This is a case-control study including 50 kidney transplant recipients and 50 controls. The sputum samples were collected from 50 kidney transplant recipients with bronchopulmonary infection signs suspected to lophomoniasis admitted in Montaserieh and Imam Reza hospitals, Mashhad, Iran. 50 healthy individuals as the control group were matched for sex and age with case ones. The consent form, checklist, and required information were provided for each patient. All samples were microscopically examined for the flagellated protozoan, L. blattarum, using direct smear. Results Among 50 kidney transplant recipients suspected to lophomoniasis, L. blattarum was identified in sputum samples of 4 (8%) participants of the case group including one female and three males. None of the samples were positive among the control group. Symptoms in patients of this study were high fever (4 out of 4 patients), cough (3 out of 4 patients), and dyspnea (2 out of 4 patients). Three patients showed a positive response to metronidazole treatment. Conclusion The results of this study suggest that L. blattarum should be considered as a pathogenic agent in kidney transplant recipients. It is necessary to examine sputum samples in posttransplant pneumonia patients, especially in those resistant to antibacterial therapy.

Lophomonas blattarum - A blunder!

Background: Lophomonas blattarum is a parasite colonising gut of cockroaches. There are 136 case reports from immunocompromised patients and children suffering from respiratory tract infections. Here we report a case where broncho alveolar lavage fluid from a child showed structures which convincingly appeared like a flagellate parasite but was later confirmed to be ciliocytophthoria. Case Description: A 5 y old female child hailing from rural southern India came with complaints of cough, cold and abdominal pain since 6 m. In view of increased severity of symptoms, high grade fever and cavitatory lesions in the lung, the child was referred to our centre. We considered the differential diagnoses - Hydatid cyst, Tuberculosis, non infectious causes of lung cyst. Investigations showed Eosinophilia and raised ESR. CT scan of chest showed consolidation with cavities involving apical segment of right lower lobe, anterior segment of left upper lobe suggestive of infective etiology. Broncho alveolar lavage fluid was negative for acid fast bacilli and TB PCR. On wet mount examination, motile structures appearing to have tuft of flagella were seen. Modified Trichrome stain showed numerous inflammatory cells and pyriform shaped structures with tuft of flagella arranged irregularly at one pole. Inner structures were not appreciated very clearly and a presumptive diagnosis of the parasite Lophomonas blattarum was made. The patient was treated with metronidazole 7.5 mg/kg body weight for 10 d awaiting further results. Child improved symptomatically and discharged. Discussion: Since it was difficult to do the molecular tests, we sent the micrscopic photographs and videos to CDC Diagnostic Assistance team to help us solve the case. They confirmed it to be ciliocytophthoria. Bronchial epithelial cells are cylindrical with basal nuclei and a visible terminal bar just beneath the regularly arranged cilia at the other end. This was a learning experience for us to differenciate the cells from the parasite. We now routinely perform special stains on samples found to have motile structures like these. Conclusion: Lophomonas blattarum rarely causes human disease more often misdiagnosed because the movement of the flagellate parasite resembles the motion of detached ciliated bronchoepithelial cells when brochoalveolar lavage fluid is examined under the microscope.

Pulmonary Infection with Lophomonas blattarum.

ObjectiveTo describe the characteristics of Lophomonas blattarum infection in children based on a retrospective review of medical records data from Beijing Children’s Hospital, Capital Medical University, China.MethodsThis study included 53 cases from July 2014 through December 2016. The data were tabulated and statistically analysed in a Microsoft Excel spreadsheet and SPSS 17.0.ResultsThe average age of the 53 patients was 7.10 ± 0.56 years, and the male/female ratio was 3:2.3. The most common clinical manifestation was cough, and almost half of the patients had fever. Furthermore, all patients were treated with metronidazole and recovered.ConclusionsFor children who have had long-term respiratory symptoms, the possibility of Lophomonas blattarum infection should be ruled out. Metronidazole is effective in treating L. blattarum infection in children.

Protozoan Cysts in Faecal Pellets of German Cockroaches (Blattella germanica), with Particular Emphasis on Lophomonas blattarum

PurposeThe aim of this study was to investigate protozoan cysts and oocyts in the faecal pellets of the German cockroach (Blattella germanica), with emphasis on the prevalence of Lophomonas blattarum.MethodsThirty adult Blattella germanica (12 males; 18 females) were trapped near Madrid, Spain. Expelled faecal pellets were collected in the laboratory over 5 days in two plastic containers. Protozoan cysts from one container were weighted and those in the other used for morphologically identification.ResultsProtozoan cysts/oocysts per gram of faecal pellet were: Nyctotherus sp. (0.0019/g), Entamoeba (0.0007/g), Balantidium coli (0.0001/g), Lophomonas blattarum (0.00038/g). Observation of 189 protozoan cysts/oocysts indicated the following prevalence: Nyctotherus sp. 65 (34.4%); Gregarina spp. 34 (18%); Entamoeba sp. 24 (12.7%); Cryptosporidium sp. 17 (9%); Coccidia 16 (8.4%); Lophomonas blattarum 13 (6.8%); Balantidium coli 4 (2.1%); and unclassified 16 (8.4%).ConclusionLophomonas blattarum has previously been demonstrated in the gut of cockroaches, but this is the first assessment of the prevalence in Blattella germanica in faecal pellets. The presence of protozoa in faecal pellets provides some evidence for one step in a hypothesised route of respiratory infection whereby protozoa from household insects enter the respiratory tract.