Comparison of Sensitivity of Sucrose Gradient, Wet Mount and Formalin - Ether in Detecting Protozoan Giardia lamblia in Stool Specimens of BALB/c Mice

Prevalence of Giardia duodenalis among African children: A systematic review and meta-analysis

Background

Giardia duodenalis (G. duodenalis) is one of the major causes of diarrhea among children. We performed a systematic review and meta-analysis to assess the prevalence of G. duodenalis and associated risk factors among African children.

Methods

We searched online databases (PubMed, Scopus, and Web of Science) as well as the Google Scholar search engine for studies measured the prevalence of G. duodenalis among African children, published between 1 January 2000 and 15 March 2022. Due to high heterogeneity among the included studies, a random-effects meta-analysis model was employed to estimate pooled prevalence and 95% confidence intervals (CI).

Results

A total of 114 articles from 29 African countries met the inclusion criteria. The pooled prevalence of G. duodenalis infection among African children was estimated as 18.3% (95% CI: 16.5-20.2). The highest and lowest pooled prevalence of G. duodenalis infection were estimated in Niger and Cameroon as 65.1% (55-75.2) and 0.08% (0.02-1.05), respectively. Considering the type of study population, the highest prevalence was related to, iron-deficient children 65.2% (61.3-69.1), handicapped children 30.4% (18.3-42.4), HIV infected children 25.7% (11.2-40.2) and displaced children 20.2% (16.5-23.9).

Conclusions

Giardiasis is common among African children, hence, prevention and control scheme of this protozoan in children should be considered by health officials and health policymakers, especially in African countries where prevalence is highest.

Prevalence of Giardia duodenalis among Asian children: a systematic review and meta-analysis

Giardia duodenalis is one of the major causes of diarrhea among children. We performed a systematic review and meta-analysis to assess the prevalence of G. duodenalis and associated risk factors among Asian children. We searched online databases (PubMed, Scopus and Web of Science) and Google Scholar search engine for studies published from 1 January 2000 to 15 March 2022 that measured the prevalence of G. duodenalis among Asian children. Accordingly, the pooled prevalence and 95% CIs were estimated using a random-effects meta-analysis model for the included studies. A total of 182 articles from 22 Asian countries met the inclusion criteria. The pooled prevalence of G. duodenalis infection among Asian children was estimated as 15.1% (95% CI 14.1 to 16%). The highest and lowest pooled prevalence values of G. duodenalis infection were estimated for Tajikistan and China as 26.4% (95% CI 22.9 to 30%) and 0.6% (95% CI 0.001 to 1.02%), respectively. The infection had a higher prevalence in males than in females (OR=1.24; 95% CI 1.16 to 1.31; p<0.001), which was statistically significant. Giardiasis is common among Asian children, hence, a prevention and control scheme of this protozoan in children should be considered by health officials and health policymakers, especially in Asian countries where the prevalence is highest.

A 'One Health' perspective of Africa-wide distribution and prevalence of Giardia species in humans, animals and waterbodies: a systematic review and meta-analysis

Giardiasis, caused by Giardia duodenalis, is a leading cause of diarrhoea in resource-poor countries. To gain a better insight into the epidemiology of Giardia in Africa, we undertook a robust study to comprehend the distribution and prevalence of Giardia infection in humans, animals and their dispersal in the environment. Our protocol was registered with PROSPERO (registration number CRD42022317653). Deep literature search from 5 electronic databases, namely, AJOL, Google scholar, PubMed, ScienceDirect and Springer Link was performed using relevant keywords. Meta-analysis was performed using a random-effects model and heterogeneity among studies was evaluated using Cochran's Q and the I2-statistic. More than 500 eligible studies published from 1 January 1980 until 22 March 2022 were retrieved. In humans, exactly 48 124 Giardia spp. infection cases were registered from the 494 014 stool samples examined resulting in a pooled prevalence estimate (PPE) of 8.8% using microscopy. Whereas copro-antigen tests and molecular diagnostic methods generated PPE of 14.3 and 19.5%, respectively, with HIV+ subjects and those with diarrhoeatic stool having infection rates of 5.0 and 12.3%, respectively. The PPE of Giardia spp. infection in animals using molecular methods was 15.6%, which was most prevalent in pigs (25.2%) with Nigeria registering the highest prevalence at 20.1%. The PPE of Giardia spp. contamination from waterbodies was 11.9% from a total of 7950 samples which were detected using microscopy, with Tunisia documenting the highest infection rate of 37.3%. This meta-analysis highlights the necessity of ‘One Health’ approach for consolidated epidemiological studies and control of giardiasis in the African continent.

In Vitro Antiprotozoal Effects of Nano-chitosan on Plasmodium falciparum, Giardia lamblia and Trichomonas vaginalis

BACKGROUND

Treatment of parasitic infections with conventional drugs is associated with high toxicity, and undesirable side effects require cogent substitutions. Nanotechnology has provided novel approaches to synthesize nano-drugs to improve efficient antipathetic treatment.

PURPOSE

Nano-chitosan as a nontoxic antimicrobial agent was examined against three most prevalent protozoa in humans, Plasmodium falciparum, Giardia lamblia and Trichomonas vaginalis.

METHODS

Chitosan extracted from Penicillium fungi was converted to nanoparticles to maximize its therapeutic properties. Safety of nano-chitosan was examined by determining its hemolytic property and toxicity on PC12 cells. The studied parasites were identified with RFLP-PCR and cultivation in relevant media. Characteristics of nano-chitosan as an useful and valuable curative compound was evaluated by FTIR, DLS and SEM. Dose dependent anti-parasitic effect of nano-chitosan was evaluated.

RESULTS

The highest anti-parasitic activity of the nano-chitosan was observed at 50 μg/mL by which growth rates of cultivated P. falciparum, T. vaginalis and G. lamblia were inhibited by 59.5%, 99.4%, and 31.3%, respectively. The study demonstrated that nano-chitosan with the least toxicity, low side effects, and substantial efficacy deserved to be considered as an anti-parasitic nano-compound.

CONCLUSION

Nano-chitosan significantly inhibited protozoan growth in vitro promising to explore its use to combat parasitic infections. Further investigations covering extended sample size, in vivo experiments and optimizing the concentration used may lead to efficient treatment of protozoan diseases.

Human intestinal parasitic infection: a narrative review on global prevalence and epidemiological insights on preventive, therapeutic and diagnostic strategies for future perspectives

INTRODUCTION

Intestinal parasitic infection (IPI) is a global health concern among socioeconomically deprived communities in many developing countries. Many preventative strategies have been deployed to control IPI, however, there is a lack in standards on the techniques used to diagnose and monitor the prevalence of IPI.

AREAS COVERED

The present article will review the diseases associated with IPI and discuss the current IPI control strategies such as the water, sanitation, and hygiene (WASH) interventions, community-led total sanitation (CLTS) approach, and regular anthelminthic treatments. For the first time, this review will also evaluate all currently practised diagnostic techniques for the detection of intestinal parasites and provide insights on future IPI control strategies.

EXPERT OPINION

Advanced and improved diagnostic methods such as qPCR coupled with a high-resolution melting curve, aptamers, biosensors, and detection of extracellular vesicles can be used for detection of IPI. Vaccination against intestinal parasites can be made available to increase antibodies to interfere with the blood-feeding process by the parasites, which subsequently reduces the reproductive rates of the parasites. These methods collectively can serve as future management strategies for intestinal parasitic infections.

Epidemiology of human giardiasis in Romania: A 14 years survey

Giardia spp. is the most common intestinal protozoan (causing gastrointestinal illness) and the most frequent cause of parasitic gastroenteritis in humans and animals worldwide. The aim of this study was to highlight new data in a specific area regarding clinical presentation and epidemiological prevalence over a long period of time. Patients (a total number of 54,623 patients) admitted in a tertiary center for infectious diseases serving a county for a period of 14 years were tested for infection with Giardia. Positive cases were recorded through analyzing the clinical complaints, the month of incidence and the demographic area from which the patients came from. Longitudinal trends have been evaluated. The incidence of giardiasis among the tested patients was 4.47%. A decreasing trend was observed regarding the annual incidence. Patients between the ages of 15 and 44 presented most commonly giardiasis, especially those from urban areas and women. The most common symptoms are loss of appetite (71.24%) and abdominal pain (69.07%). The highest monthly incidence was quoted in July (10.65%), August (10.49%) and June (10.20%). This epidemiological study allows a better knowledge of the infection with Giardia spp. It gives the long-term changes in demographic characteristics of the infected patients in a specific area and the monthly incidence.

Effects of some natural products from fungal and herbal sources on Giardia lamblia in vivo

Giardia lamblia (G. lamblia) is the most widely known protozoan parasite that causes human gastrointestinal infection worldwide. Some natural compounds exhibited pivotal effects against different infectious diseases. In this research, the antigiardial activity and cytotoxicity of fungal chitosan, nano-chitosan, Rhamnus cathartica (R. cathartica) and emodin were evaluated in Balb/c mice. Genotyping of G. lamblia was assessed by PCR-RFLP technique. Different concentrations of mentioned compounds were used to check their antigiardial and cytotoxicity effects on human intestinal epithelial cells (HT-29) after 24, 48 and 72 h. The G. lamblia strain used in the current work was genotyped and revealed as an AII assemblage. All the concentration showed acceptable activity against G. lamblia cysts and trophozoites in comparison to the negative and positive controls (furazolidone and metronidazole) in vitro (P 0.05). The maximum mortality rate (100%) was achieved at 100 and 50 µg kg-1 concentrations after 48 and 72 h of exposure time, respectively. Our results provide significant information about the new antigiardial agent and proposed the nano-chitosan and emodin for the development of new drugs against G. lamblia in the future.