Diagnostic Methods of Common Intestinal Protozoa: Current and Future Immunological and Molecular Methods

Electrochemical biosensors for the detection of protozoan parasite: a scoping review

The development of rapid, accurate, and efficient detection methods for protozoan parasites can substantially control the outbreak of protozoan parasites infection, which poses a threat to global public health. Idealistically, electrochemical biosensors would be able to overcome the limitations of current detection methods due to their simplified detection procedure, on-site quantitative analysis, rapid detection time, high sensitivity, and portability. The objective of this scoping review is to evaluate the current state of electrochemical biosensors for detecting protozoan parasites. This review followed the most recent Preferred Reporting Items for Systematic Review and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) recommendations. Using electrochemical biosensor and protozoan parasite keywords, a literature search was conducted in PubMed, Scopus, Web of Science, and ScienceDirect on journals published between January 2014 and January 2022. Of the 52 studies, 19 were evaluated for eligibility, and 11 met the review's inclusion criteria to evaluate the effectiveness and limitations of the developed electrochemical biosensor platforms for detecting protozoan parasite including information about the samples, biomarkers, bioreceptors, detection system platform, nanomaterials used in fabrication, and limit of detection (LoD). Most electrochemical biosensors were fabricated using conventional electrodes rather than screen-printed electrodes (SPE). The range of the linear calibration curves for the developed electrochemical biosensors was between 200 ng/ml and 0.77 pM. The encouraging detection performance of the electrochemical biosensors demonstrate their potential as a superior alternative to existing detection techniques. On the other hand, more study is needed to determine the sensitivity and specificity of the electrochemical sensing platform for protozoan parasite detection.

Amebic liver abscess: An update

Amebic liver abscess (ALA) is still a common problem in the tropical world, where it affects over three-quarters of patients with liver abscess. It is caused by an anaerobic protozoan Entamoeba hystolytica, which primarily colonises the cecum. It is a non-suppurative infection of the liver consisting primarily of dead hepatocytes and cellular debris. People of the male gender, during their reproductive years, are most prone to ALA, and this appears to be due to a poorly mounted immune response linked to serum testosterone levels. ALA is more common in the right lobe of the liver, is strongly associated with alcohol consumption, and can heal without the need for drainage. While majority of ALA patients have an uncomplicated course, a number of complications have been described, including rupture into abdomino-thoracic structures, biliary fistula, vascular thrombosis, bilio-vascular compression, and secondary bacterial infection. Based on clinico-radiological findings, a classification system for ALA has emerged recently, which can assist clinicians in making treatment decisions. Recent research has revealed the role of venous thrombosis-related ischemia in the severity of ALA. Recent years have seen the development and refinement of newer molecular diagnostic techniques that can greatly aid in overcoming the diagnostic challenge in endemic area where serology-based tests have limited accuracy. Metronidazole has been the drug of choice for ALA patients for many years. However, concerns over the resistance and adverse effects necessitate the creation of new, safe, and potent antiamebic medications. Although the indication of the drainage of uncomplicated ALA has become more clear, high-quality randomised trials are still necessary for robust conclusions. Percutaneous drainage appears to be a viable option for patients with ruptured ALA and diffuse peritonitis, for whom surgery represents a significant risk of mortality. With regard to all of the aforementioned issues, this article intends to present an updated review of ALA.

Beyond schistosomiasis: unraveling co-infections and altered immunity

Schistosomiasis is a neglected tropical disease caused by the helminth Schistosoma spp. and has the second highest global impact of all parasites. Schistosoma are transmitted through contact with contaminated fresh water predominantly in Africa, Asia, the Middle East, and South America. Due to the widespread prevalence of Schistosoma, co-infection with other infectious agents is common but often poorly described. Herein, we review recent literature describing the impact of Schistosoma co-infection between species and Schistosoma co-infection with blood-borne protozoa, soil-transmitted helminths, various intestinal protozoa, Mycobacterium, Salmonella, various urinary tract infection-causing agents, and viral pathogens. In each case, disease severity and, of particular interest, the immune landscape, are altered as a consequence of co-infection. Understanding the impact of schistosomiasis co-infections will be important when considering treatment strategies and vaccine development moving forward.

Intestinal parasitic infections and their potential risk factors among prison inmates in Valencia, Spain

BACKGROUND

Despite the fact that prison inmates are a population at higher risk than other groups of suffering from intestinal parasite infections in relation to their living conditions, information about these diseases in prison environments is still scarce. Herein, we analyze the status of intestinal parasite infections in a Spanish prison.

METHODS

A cross-sectional study involving 528 inmates was conducted from April to June 2022 among inmates at Centro Penitenciario Picassent (Valencia, Spain). Stool specimens were examined using the direct wet mount technique, the formol-ether concentration technique, and the Ziehl-Neelsen staining method. We used STATA 16.1 for data analysis. We consider a p-value less than 0.05 significant at a 95% confidence level.

RESULTS

Of the 528 inmates (471 men and 57 women; a mean age of 41.94 years) enrolled in the study, 83 (15.7%) were infected. Only six species of protozoa were detected. The gut potential microeukaryotic pathobiont Blastocystis sp. was the predominant parasite, accounting for 37 (44.6%) of the infections. Gut parasite amebas (6.6%) and pathobionts (5.3%) were more prevalent than flagellates (2.3%). The prevalence of infection with pathogenic species (8.9%) was similar to that of non-pathogenic species (8.7%). Infection among men (15.2%) was higher than in women (0.6%) (p < 0.0001). In multivariate analysis, the country of birth (AOR = 0.31, 95% CI = 0.18-0.52) and the time spent in prison (AOR = 1.83, 95% CI = 1.06-3.14) were statistically significant associated to intestinal parasite infections (p < 0.0001 and p = 0.028, respectively).

CONCLUSION

This study found low levels of intestinal parasite infections in the CPP which could be indicative of the implementation of sanitary measures in prison environments in Spain. The less time spent in prison favor the risk of having infection while the Spanish nationality of inmates could reduce the risk of infection. The main recommendation would be to introduce routine parasitological tests upon foreigners entering prison.