A systematic review and meta-analysis of Hymenolepis nana in human and rodent hosts in Iran: A remaining public health concern

A systematic review and meta-analysis on prevalence of gastrointestinal helminthic infections in rodents of Iran: An emphasis on zoonotic aspects

Rodents are the largest group of mammals that adapt to different ecosystems and may act as the potential reservoirs of significant pathogens including gastrointestinal (GI) helminths. Rodent-borne parasitic pathogens have been and remain a great concern for animal and human health. The aim of this systematic review and meta-analysis is thus to clarify and better understand the pooled prevalence of GI helminthic infections and the associated risk factors in rodents in Iran. Multiple databases (PubMed, Scopus, Web of Science, Google Scholar, SID, Magiran and Irandoc) were searched for relevant literature published up to March 2022. A random-effects meta-analysis model was applied to estimate the pooled prevalence with 95 % confidence interval. Moreover, heterogeneity among studies was evaluated using the Cochran's Q test and the I 2-statistic. Out of the 5438 publications searched, 28 articles (30 datasets) were ultimately eligible for inclusion in the study. Thus, 3649 captured rodents belonging to 6 families, 20 genera, and 35 species were examined for GI helminths in Iran. Then, 54 helminth species were identified in the present research, including 33 nematodes, 16 cestodes, 4 trematods, and 1 acanthocephalan. The prevalence rate of GI parasitic infections was 56 % (95 % CI: 50-63 %). Hymenolepis diminuta, Syphacia obvelata and Rodentolepis nana were the most common helminthic infections (13 %, 9 %, and 8 %, respectively). Moreover, 11 potential zoonotic helminths were found. There was no significant difference in pooled prevalence between male and female rodents (P = 0.40). Considering geographical areas, northern and eastern provinces had the highest prevalence of GI helminthic infections among rodents. The prevalence of GI worms in Iranian rodents was as high as 56 % with 11 zoonotic helminths. Therefore, it is suggested to observe the health of the environment, destroy the biological nests of rodents, avoid half-finished constructions, repair and improve streams and sidewalks, organize and collect garbage, and carry out biological and chemical control to handle the population of rodents. Increasing the awareness of local people about the harmful effects of rodents and the ways of transmission and prevention of rodent-borne intestinal worms transmitted to humans should be prioritized in health decisions.

Answer to the Photo Quiz: An unexpected visitor

Read the full article for the answer.

Gastrointestinal parasites in Africa: A review

Data on human gastrointestinal parasites (GIP) infections in the african sub-regions and countries are mainly lacking in terms of prevalence and population stratification by afflicted age group, symptomatology, multi-parasitism, and diagnostic methods. This study aims to describe the GIP reported in african countries and discuss the extent of the burden in the african context. Only 68.42% (39/57) of african countries reported human cases of GIP with helminths (45%, CI: 40-50%, I²: 99.79%) as the predominant parasitic group infecting the african population. On a regional scale, Central Africa had the highest pooled prevalence for GIP (43%, CI: 32-54%, I²: 99.74%), while the Central African Republic led all countries with a pooled prevalence of 90% (CI: 89-92%, I²: 99.96%). The vulnerable population (patients who are minorities, children, old, poor, underfunded, or have particular medical conditions) was the most affected (50%, CI: 37-62%, I²: 99.33%), with the predominance of GIP in the 6 to <20 years age group (48%, CI: 43-54%, I²: 99.68%). Reports on multi-parasitism (44%, CI: 40-48%, I²: 99.73%) were almost double the reports of single infections (43%, CI: 27-59%, I²: 99.77%) with combined molecular and non-molecular techniques demonstrating the best performance for GIP identification. The current review spans more than 40 years of GIP reports from the african continent. Geographical characteristics, environmental factors, habits of its inhabitants, and their health status play a crucial role in GIP modulation and behaviour in its captive hosts. Strategies for regular and enhanced surveillance, policy formation, and high-level community awareness are necessary to identify the true incidence in Africa and the transmission of the pathogens via water and food.

Tunable Polymeric Mixed Micellar Nanoassemblies of Lutrol F127/Gelucire 44/14 for Oral Delivery of Praziquantel: A Promising Nanovector against Hymenolepis nana in Experimentally-Infected Rats

Hymenolepiasis represents a parasitic infection of common prevalence in pediatrics with intimidating impacts, particularly amongst immunocompromised patients. The present work aimed to snowball the curative outcomes of the current mainstay of hymenolepiasis chemotherapy, praziquantel (PRZ), through assembly of polymeric mixed micelles (PMMs). Such innovative nano-cargo could consolidate PRZ hydrosolubility, extend its circulation time and eventually upraise its bioavailability, thus accomplishing a nanoparadigm for hymenolepiasis tackling at lower dose levels. For consummating this goal, PRZ-PMMs were tailored via thin-film hydration technique integrating a binary system of Lutrol F127 and Gelucire 44/14. Box-Behnken design was planned for optimizing the nanoformulation variables employing Design-Expert^® software. Also, in Hymenolepis nana-infected rats, the pharmacodynamics of the optimal micellar formulation versus the analogous crude PRZ suspension were scrutinized on the 1st and 3rd days after administration of a single oral dose (12.5 or 25 mg/kg). Moreover, in vitro ovicidal activity of the monitored formulations was estimated utilizing Fuchsin vital stain. Furthermore, the in vivo pharmacokinetics were assessed in rats. The optimum PRZ-PMMs disclosed conciliation between thermodynamic and kinetic stability, high entrapment efficiency (86.29%), spherical nanosized morphology (15.18 nm), and controlled-release characteristics over 24 h (78.22%). ¹H NMR studies verified PRZ assimilation within the micellar core. Additionally, the in vivo results highlighted a significant boosted efficacy of PRZ-PMMs manifested by fecal eggs output and worm burden reduction, which was clearly evident at the lesser PRZ dose, besides a reversed effect for the intestinal histological disruptions. At 50 µg/mL, PRZ-PMMs increased the percent of non-viable eggs to 100% versus 47% for crude PRZ, whilst shell destruction and loss of embryo were only clear with the applied nano-cargo. Moreover, superior bioavailability by 3.43-fold with elongated residence time was measured for PRZ-PMMs compared to PRZ suspension. Practically, our results unravel the potential of PRZ-PMMs as an oral promising tolerable lower dose nanoplatform for more competent PRZ mass chemotherapy.

Patterns of Gastrointestinal Helminth Infections in Rattus rattus, Rattus norvegicus, and Mus musculus in Chile

Few studies have assessed the patterns of parasite populations of rodents over a longitudinal gradient in Chile. In this work, the gastrointestinal helminthic fauna of invasive rodents in Chile was examined to assess the association between their presence/absence and abundance with latitude, host sex, and host body condition, and to assess the coexistence and correlation of the abundance between parasite species. Rodents were obtained from 20 localities between 33 and 43°S. Helminths were extracted from the gastrointestinal tract and identified morphologically. Overall, 13 helminth taxa were obtained. The most frequently identified parasite species was Heterakis spumosa, and the most abundant was Syphacia muris, while Physaloptera sp. was the most widely distributed. No locality presented with a coexistence that was different from that expected by chance, while the abundance of five helminthic species correlated with the abundance of another in at least one locality, most likely due to co-infection rather than interaction. Host sex was associated with parasite presence or abundance, and female sex-biased parasitism was notably observed in all cases. Body condition and latitude presented either a positive or negative association with the presence or abundance of parasites depending on the species. It is notable that the likely native Physaloptera sp. is widely distributed among invasive rodents. Further, gravid females were found, suggesting spillback of this species to the native fauna. The low frequency and abundance of highly zoonotic hymenolepid species suggest that rodents are of low concern regarding gastrointestinal zoonotic helminths.

Intestinal parasitic infections among patients referred to hospitals affiliated to Shiraz University of Medical Sciences, southern Iran: a retrospective study in pre- and post-COVID-19 pandemic

Intestinal parasitic infections (IPIs) are still a serious public health problem worldwide, particularly in developing countries. The COVID-19 pandemic has affected people's lifestyles and quality of life. Besides, the prevalence of IPIs is directly associated with environmental sanitation, overcrowding, and personal hygiene. Therefore, the current study aimed to determine the prevalence of IPIs among patients referred to hospitals affiliated to Shiraz University of Medical Sciences by reviewing the available data of hospital information system database in the pre- and post-COVID-19 pandemic. The total data of 13,686 patients referred to hospitals affiliated to Shiraz University of Medical Sciences, southern Iran were collected from March 2019 to March 2021. The overall prevalence of IPIs was found to be 4.4%, and Blastocystis spp. was the most common parasite. The prevalence of protozoan parasites (4.4%) was significantly higher than helminthic parasites (0.04%, P < 0.001). A significant association was observed between IPIs with age, gender, and year (P < 0.05). The prevalence of IPIs among those referred to hospitals before the COVID-19 pandemic was higher than those referred to hospitals during the COVID-19 pandemic (5.8% vs 2.8%), and the differences were statistically significant (P < 0.001). The odds of infection among people investigated during the COVID-19 pandemic was about 40% lower than those investigated before the COVID-19 pandemic (AOR: 0.60, 95% CI: 0.49-0.73, P < 0.001). Our results showed that the prevalence of IPIs has decreased during the COVID-19 pandemic. Improved sanitation, personal hygiene, and health education can be effective in reducing parasitic infections in the COVID-19 pandemic.

Intestinal parasites among intellectually disabled individuals in Iran: a systematic review and meta-analysis

BACKGROUND

Poor self-care skills and personal hygiene resulted from limitations in learning and understanding, put intellectually disabled individuals at greater risk for intestinal parasitic infections (IPIs). Despite several regional reports in Iran, the overall burden on IPIs among intellectually disabled individuals is poorly understood. Hence, the present study aimed to estimate the pooled prevalence of IPIs among intellectually disabled individuals in Iran.

METHODS

Using the PRISMA guidelines, we conducted a systematic review and meta-analysis of data retrieved from seven electronic databases (PubMed, Web of Science, Scopus, Embase, and ProQuest for English articles, as well as SID and Magiran for Persian) from their inception up to December 2020. Pooled prevalence was estimated using a random-effects model with a 95% confidence interval (CI) and depicted as a forest plot, while heterogeneity was evaluated using Cochran's Q-test.

RESULTS

Exactly 1263 of the 3004 intellectually disabled individuals examined by 14 studies across 10 provinces of Iran were positive for IPIs. Overall pooled prevalence estimate was 41% (95% CI 29-53%) with a range of 21% (95% CI 10-32%) to 68% (95% CI 55-80%) across sub-groups. Entamoeba coli (16.2%; 95% CI 10.3-22%), Blastocystis spp. (12.2%; 95% CI 7.2-17.2%), and Giardia duodenalis (11.9%; 95% CI 7.4-16.3%) were the most prevalent protozoan species. In terms of helminthic agents, the most prevalent species were Enterobius vermicularis (11.3%; 95% CI 6.3-16.3%) followed by Strongyloides stercoralis (10.9%; 95% CI 5.0-16.9%) and Hymenolepis nana (2.8%; 95% CI 0.4-5.2%) CONCLUSION: IPIs are highly prevalent among intellectually disabled individuals in Iran. Improving the health status and implementing infectious disease prevention strategies in rehabilitation centers, health promotion interventions to improve personal hygiene of intellectually disabled individuals, as well as utilize sensitive diagnostic methods besides routine stool examination techniques, and treatment of infected individuals will help in the control of these infections among intellectually disabled individuals.

Parasites of Native and Invasive Rodents in Chile: Ecological and Human Health Needs

Invasive populations are a threat to biodiversity, resulting in the loss of species, and also a threat to human health, participating in the reservoir of diseases. Rodents are among the most important invasive species worldwide. Chile is a country that features island conditions in terms of geography and has been widely invaded by allochthonous rodents. In this mini-review, we updated the literature on macro-parasites infecting both native and invasive rodents and of vector-borne pathogens in continental Chile in order to assess the relative importance of invasive rodents from both ecological and public health points of view. A total of 174 parasite species were found, with Siphonaptera representing the most diverse group. When examining how parasites are shared between native and introduced rodents, the analysis suggests that parasites circulate freely within recipient populations, and are not significantly transmitted from source populations. Further, generalist parasites are typically more prone to being shared between native and introduced rodents. Most zoonotic parasites were reported in invasive rodents, suggesting that these rodents must represent a public health concern. Although several vector-borne pathogens have been reported in rodents or ectoparasites, most of the recently emerging research has illustrated that there is a lack of evidence on rodent-vector-borne zoonoses in most pathogens.