Prevalence and risk factors of intestinal protozoan infection among symptomatic and asymptomatic populations in rural and urban areas of southern Algeria

Prevalence of Blastocystis sp. in Morocco: Comparative assessment of three diagnostic methods and characterization of parasite forms in Jones' culture medium

Blastocystosis is an infection caused by Blastocystis sp., which colonizes the digestive tract of various hosts, including humans, although its pathogenicity is debated. It is crucial to detect and distinguish the different forms of Blastocystis to understand better its impact on human health and its epidemiological evolution. This study evaluated three diagnostic methods on 105 stool samples: direct examination, culture in Jones' medium, and conventional PCR. PCR is considered the gold standard and revealed a high prevalence of Blastocystis (67.62%) compared to direct examination (20.95%) and culture in Jones' medium (51.43%). Although the sensitivity of direct examination and culture was 31% and 76.1%, respectively, their specificity was 100%. No significant risk factors were identified. A statistically significant association was observed between Blastocystis infection and abdominal pain. Microscopic analysis revealed various morphological forms. Molecular diagnosis is an essential tool to determine the true prevalence of Blastocystis, and studying the different forms of this microorganism will contribute to a better understanding of its biological cycle and, therefore, the impact of this emerging infection on human health.

Prevalence of Intestinal Parasites and Associated Risk Factors among Diarrheal Patients Attending Negelle Borena General Hospital: A Case-Control Study

Background

In tropical countries, intestinal protozoal parasitic infections are among the common infections causing significant morbidity and mortality. Thus, the present study was conducted to assess the status of intestinal protozoal parasitic infections among diarrheal patients attending Negelle Borena General Hospital and investigate the possible risk factors for the infection.

Methods

A case-control study design was employed in the study. The intestinal protozoal parasites were detected using a wet-mount, stool concentration, and modified Ziehl-Neelsen methods. The crude and adjusted odd ratios were considered to identify the associated risk factors for intestinal protozoal parasitic infections among the study participants.

Results

The overall status of parasitic infection was 46.88% in cases and 27.08% in the control groups. The most prevalent protozoal infection was Giardia lamblia (9.38%) and followed by Entamoeba histolytica/dispar (6.25%) in the cases. The highest prevalence of the infection was detected in the age groups that varied from 6 to 10 years in cases (71%). The enteric G. lamblia and E. histolytica/dispar were found to be 33.3% and 9.1%, respectively, in the age groups of 6-10 years in cases. Based on sex, 56.50% and 27.30% of protozoal (parasitic) infections were revealed by females in the cases and control groups, respectively, indicating a significant variation (P < 0.05). The education level (illiteracy), absence of toilet usage, no hand washing after toilet and before eating as significant risk factors for patient's infection with G. lamblia, E. histolytica, and Cryptosporidium spp. (P < 0.05, AOR = 1-14). However, eating raw fruit and vegetables was also found as a major risk factor for E. histolytica (P < 0.05, AOR = 6.2) 40. Moreover, the residence of the patients was also indicated as a plus risk factors for the infection to be occurred by Cryptosporidium spp. in the study participants (P > 0.95, AOR = 0.2).

Conclusion

The prevalence of intestinal protozoal parasitic infection showed variation based on age, sex, and educational background of the study participants. Therefore, awareness creating training should be provided to the Negelle area communities so as to minimize the parasitic infection.

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.

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.

[Molecular characterization of algerian strains of Blastocysts sp]

INTRODUCTION

Blastocystis sp. is a protozoan that colonizes the gastrointestinal tract of humans and many animals and is currently the most common parasite found in human stools. In some developing countries, its prevalence in study populations may exceed 50%. Morphologically, isolates of Blastocystis sp. found in different hosts are very similar. However, these same isolates show a very high genetic diversity between them and no less than 17 subtypes (or genotypes) have already been identified from molecular data. Genotyping studies have been carried out in many countries around the world and in particular in some Mediterranean countries such as France, spain, Italy, Turkey and Egypt. However, very little genotyping data is available in Algeria. To this end, we conducted the present study to identify and genotype Blastocystis in human and animal stool samples.

PATIENTS AND METHODS

One thousand eight hundred and sixty-nine (1,869) stool samples from kitchen staff as part of the periodic medical check-up, from subjects for the provision of a medical certificate required for the processing of a visa file and from patients with gastrointestinal disorders were examined. In addition to human faeces, animal samples, including 10 poultry, 2 cattle and 2 murine animals were examined. All stools were subjected to direct microscopic examination supplemented by concentration techniques and modified Ziehl Neelsen staining. Molecular characterization of 39 human and 14 animal isolates was performed by sequencing and the resulting sequences compared with those available from GenBank. Sequencing was only contributory for 30 human and 9 animal strains.

RESULTS

Of all human samples examined 284 were positive (15.19%) with a prevalence of 7.38% for Blastocystis. Of the 30 strains that were molecularly characterized, ST3 was predominant (15/30, 50%) followed by ST1 (10/30, 33.33%) and in third place ST2 (4/30, 13.33%). ST4 was identified in only one patient (1/30, 3.33%). The correlation between clinical status and the subtype of Blastocystis identified showed that the number of ST3 was high in asymptomatic subjects (11/15, 73%) compared to symptomatic subjects (4/15, 26.66%), as well as for the ST1 subtype (7/10, 70% versus 3/10, 30%). Conversely, the number of ST2 was higher in subjects with gastrointestinal disorders (3/4, 75%). In addition to human strains, we genotyped 7 avian, 2 murine and 2 bovine strains. Characterization of the avian strains revealed 5 ST6 (71.42%) and 2 ST7 (28, 57%). The murine and bovine strains are identified as ST7 and ST6 respectively.

Detection, Molecular Identification and Transmission of the Intestinal Protozoa Blastocystis sp. in Guinea from a Large-Scale Epidemiological Study Conducted in the Conakry Area

Blastocystis sp. is a single-celled parasite estimated to colonize the digestive tract of 1 to 2 billion people worldwide. Although it represents the most frequent intestinal protozoa in human stools, it remains still under-investigated in countries with a high risk of infection due to poor sanitary and hygiene conditions, such as in Africa. Therefore, the present study was carried out to determine the prevalence and subtype (ST) distribution of Blastocystis sp. in the Guinean population. For this purpose, fecal samples were collected from 500 individuals presenting or not digestive disorders in two hospitals of Conakry. Search for the parasite in stools was performed by real-time PCR targeting the small subunit rDNA gene followed by sequencing of the PCR products for subtyping of the isolates. A total of 390 participants (78.0%) was positive for Blastocystis sp. Five STs were identified in the Guinean cohort (ST1, ST2, ST3, ST4 and ST14) with varying frequency, ST3 being predominant. Among them, ST4 was found in only two patients confirming its global rarity in Africa whereas infections by ST14 were likely the result of zoonotic transmission from bovid. No significant association was detected between Blastocystis sp. colonization or ST distribution and the symptomatic status of Guinean subjects or the presence of digestive symptoms. In contrast, drilling water consumption represented a significant risk factor for infection by Blastocystis sp. Predominance of ST3 coupled with its low intra-ST diversity strongly suggested large-scale human-to-human transmission of this ST within this cohort. In parallel, the highest intra-ST diversity of ST1 and ST2 was likely correlated with various potential sources of infection in addition to anthroponotic transmission. These findings highlighted the active circulation of the parasite in Guinea as reported in some low-income African countries and the necessity to implement prevention and control measures in order to limit the circulation of this parasite in this endemic geographical area.