The Epidemiology of Entamoeba histolytica Infection and Its Associated Risk Factors among Domestic and Imported Patients in Taiwan during the 2011-2020 Period

Infectious foodborne disease outbreaks and sporadic cases in Saudi Arabia: A 2017-2023 trend analysis

AIM

The present study aims to precisely indicate the status of infectious foodborne disease in Saudi Arabia between 2017 and 2023.

SUBJECT AND METHODS

A trend analysis was conducted based on epidemiologic data in Saudi Arabia during 2017-2023. The data include reports from governmental and private health agencies regarding Saudi citizens and residents, whatever their ages, who were diagnosed with infectious foodborne disease. Outbreak and sporadic patients were evaluated. Saudi Arabian crude incidence rates per 100,000 inhabitants and foodborne pathogens were established.

RESULTS

All in all, 42,079 infectious foodborne illnesses were reported in Saudi Arabia between 2017 and 2023; the crude incidence rate averaged 18.0 ± 5.7 per 100,000. In 2017-2023, there were 12,710 foodborne outbreaks with a mean incidence rate of 5.4 ± 2.2 per 100,000. Results also indicate 29,369 sporadic cases reported during 2017-2023, with a mean crude incidence rate of 12.6 ± 3.9 per 100,000. The most widely described pathogen was Entamoeba spp. (mean crude incidence rate of 6.3 per 100,000), followed by Salmonella spp. (5.6 per 100,000), Hepatitis A virus (0.5 per 100,000), and Shigella spp. (0.2 per 100,000).

CONCLUSION

This research presents trends regarding for confirmed infectious foodborne cases in Saudi regions from 2017 to 2023. Outbreak-related and sporadic cases have decreased in recent years. Given the high incidence of Entamoeba and Salmonella spp. in foodborne sporadic cases, health agencies are called upon to use diagnostic tools for frequently reported microbes in view of identifying and locating foodborne outbreaks.

Risk of Environmental Contamination by Gastrointestinal Parasites in Public Areas of the Central Plateau Microregion of Brazil: A Public Health Concern

The risk of zoonotic parasitic infections is closely linked to direct and indirect interactions between animals and humans. The mutual coexistence of species in public spaces predisposes individuals to gastrointestinal parasitosis owing to various social and hygienic-sanitary factors. This study aimed to assess the risk of environmental contamination by gastrointestinal parasites in fecal samples collected from parks and public squares in 18 municipalities located in a microregion of the central plateau of Brazil, correlating the collection with the population size of each municipality. We collected 536 soil fecal samples from 117 randomly selected public areas across a 56,111.874 km2 region. Eggs, cysts, and oocysts were detected using the Willis flotation technique and the Hoffman's spontaneous sedimentation method. The Hoffman's analysis revealed that 70.3% of the fecal samples were infected across 91.5% of the sampled areas. Identified parasites included the members of the family Ancylostomatidae (56.5%), Toxocara spp. (6.2%), Trichuris spp. (1.7%), Strongyloides spp. (0.2%), Dipylidium caninum (25.8%), Spirometra spp. (0.4%), Taeniidae (0.2%), Platynosomum fastosum (0.6%), Trematoda (0.2%), Giardia spp. (3.2%), Cystoisospora spp. (5.6%), Sarcocystis spp. (0.2%), and Entamoeba spp. (2.4%). The presence of positive fecal samples in public areas and municipalities correlated with populations of up to 10,000 inhabitants (p = 0.023). Areas contaminated with feces were 63.4% more likely to contain parasites than other areas (odds ratio 1.6336). Favorable environmental factors combined with inadequate sanitary management contribute to a high risk of environmental contamination, representing a significant zoonotic potential and highlighting the need for improved public health policies and preventive measures.

Decision tree-based learning and laboratory data mining: an efficient approach to amebiasis testing

BACKGROUND

Amebiasis represents a significant global health concern. This is especially evident in developing countries, where infections are more common. The primary diagnostic method in laboratories involves the microscopy of stool samples. However, this approach can sometimes result in the misinterpretation of amebiasis as other gastroenteritis (GE) conditions. The goal of the work is to produce a machine learning (ML) model that uses laboratory findings and demographic information to automatically predict amebiasis.

METHOD

Data extracted from Jordanian electronic medical records (EMR) between 2020 and 2022 comprised 763 amebic cases and 314 nonamebic cases. Patient demographics, clinical signs, microscopic diagnoses, and leukocyte counts were used to train eight decision tree algorithms and compare their accuracy of predictions. Feature ranking and correlation methods were implemented to enhance the accuracy of classifying amebiasis from other conditions.

RESULTS

The primary dependent variables distinguishing amebiasis include the percentage of neutrophils, mucus presence, and the counts of red blood cells (RBCs) and white blood cells (WBCs) in stool samples. Prediction accuracy and precision ranged from 92% to 94.6% when employing decision tree classifiers including decision tree (DT), random forest (RF), XGBoost, AdaBoost, and gradient boosting (GB). However, the optimized RF model demonstrated an area under the curve (AUC) of 98% for detecting amebiasis from laboratory data, utilizing only 300 estimators with a max depth of 20. This study highlights that amebiasis is a significant health concern in Jordan, responsible for 17.22% of all gastroenteritis episodes in this study. Male sex and age were associated with higher incidence of amebiasis (P = 0.014), with over 25% of cases occurring in infants and toddlers.

CONCLUSIONS

The application of ML to EMR can accurately predict amebiasis. This finding significantly contributes to the emerging use of ML as a decision support system in parasitic disease diagnosis.

Epidemiological Features, Clinical Symptoms, and Environmental Risk Factors for Notifiable Japanese Encephalitis in Taiwan From 2008 to 2020: Retrospective Study

Background

Japanese encephalitis (JE) is a zoonotic parasitic disease caused by the Japanese encephalitis virus (JEV), and may cause fever, nausea, headache, or meningitis. It is currently unclear whether the epidemiological characteristics of the JEV have been affected by the extreme climatic conditions that have been observed in recent years.

Objective

This study aimed to examine the epidemiological characteristics, trends, and potential risk factors of JE in Taiwan from 2008 to 2020. Specifically, the study focused on gender, age, season, residential area, clinical manifestations, high-risk areas, and the impact of environmental and climate factors.

Methods

This study reviewed publicly available annual summary data on reported JE cases in the Taiwan Centers for Diseases Control between 2008 and 2020.

Results

This study collected 309 confirmed domestic patients and 4 patients with imported JE. There was an increasing trend in the incidence of JE, 0.69-1.57 cases per 1,000,000 people, peaking in 2018. Case fatality rate was 7.7% (24/313). Comparing sex, age, season, and place of residence, the incidence rate was highest in males, 40- to 59-year-old patients, summer, and the Eastern region, with 1.89, 3.27, 1.25, and 12.2 cases per million people, respectively. The average coverage rate of the JE vaccine for children in Taiwan is 94.9%. Additionally, the major clinical manifestations of the cases included fever, unconsciousness, headache, stiff necks, psychological symptoms, vomiting, and meningitis. The major occurrence places of JE included paddy fields, pig farms, pigeon farms, poultry farms, and ponds. For air pollution factors, linear regression analysis showed that SO2 (ppb) concentration was positively associated with JE cases (β=2.184, P=.02), but O3 (ppb) concentration was negatively associated with them (β=-0.157, P=.01). For climate factors, relative humidity (%) was positively associated with JE cases (β=.380, P=.02).

Conclusions

This study is the first to report confirmed cases of JE from the surveillance data of the Taiwan Centers for Diseases Control between 2008 and 2020. It identified residence, season, and age as risk factors for JE in Taiwan. Air pollution and climatic factors also influenced the rise in JE cases. This study confirmed that JE remains a prevalent infectious disease in Taiwan, with its epidemic gradually increasing in severity. These findings empower clinicians and health care providers to make informed decisions, guiding their care and resource allocation for patients with JE, a disease that significantly impacts the health and well-being of the Taiwanese population.

Epidemiological feature of imported malaria in Taiwan during the 2014-to-2020 period

Although the World Health Organization (WHO) certified Taiwan as being malaria-free in 1965, there are reports of a few imported cases each year by travelers who visit malaria-endemic areas. This study examined the epidemiology of imported malaria cases in Taiwan from 2014 to 2020, utilizing national surveillance data from the Taiwan Centers for Disease Control. Malaria cases were confirmed through the application of standard laboratory methods. Passenger data came from the Tourism Bureau, Ministry of Transportation and Communication, Taiwan (TBMTC). All data were analyzed using SPSS version 21. The analysis included a dataset comprising 64 cases of imported malaria. Of the total cases, 77.8% were acquired from Africa, and 17.5% from Asia. Plasmodium falciparum was responsible for more than half (57.1%) of the cases, Plasmodium vivax malaria for 25.4% of cases, Plasmodium malariae malaria for 6.3%, Plasmodium ovale malaria for 4.8%, and unspecified pathogen malaria for 6.3% of the cases. Majority of the patients were male (75%) and were predominantly aged 20 to 59 years (70.3%). Most cases of imported malaria occurred during the fall season, and 51.6% of cases occurred in 8 cities during the period of 2014 to 2020. No evidence exists to indicate that indigenous malaria transmission occurs in Taiwan. Anopheles minimus was found in 4 cities (counties), namely Tainan City and Pingtung County in Southern Taiwan; Hualien County and Taitung County in Eastern Taiwan. The findings of this study highlight the necessity for robust surveillance systems, effective vector control measures, and targeted interventions for travelers and immigrants to prevent malaria outbreaks and maintain Taiwan's malaria-free status.

Diloxanide in amoebiasis management: Unravelling the mechanism of action and effectiveness

Although diloxanide is a drug of choice for treating asymptomatic amoebiasis, its mechanism of action (MOA) remains unclear. This review aims to shed light on the current understanding of the effectiveness and MOA of diloxanide in treating amoebiasis . It involves analysis of articles, retrieved from PubMed, Google Scholar and EBSCOhost, on diloxanide and the treatment of Entamoeba histolytica infection. Diloxanide is used in an ester form, which allows its high luminal concentration and greater efficacy than metronidazole in the management of asymptomatic amoebiasis. The current understanding of the action of diloxanide is based on its structural similarity to chloramphenicol at dichloroacetamide group. It acts against protein synthesis in E. histolytica trophozoites, blocking their conversion to more virulent and invasive cyst forms. Furthermore, it has a parasite clearance rate of 81-96% and treats amoebic abscesses when combined with metronidazole and chloroquine. Nevertheless, it is associated with adverse events such as flatulence, anorexia, headache and urticaria. Diloxanide is efficacious against amoebiasis but there is a need to explore its structure-activity relationship.The study suggests future directions, including novel drug formulations, diagnostic improvements, and combination regimens to enhance treatment outcomes and mitigate relapse associated with the use of diloxanide.

Food and Drinking Water as Sources of Pathogenic Protozoans: An Update

This narrative review was aimed at collecting updated knowledge on the risk factors, illnesses caused, and measures for the prevention of protozoan infections transmitted by food and drinking water. Reports screened dated from 2019 to the present and regarded global prevalence in food handlers, occurrence in food and drinking water, impact on human health, and recently reported outbreaks and cases of severe infections attributable to the dietary route. Cryptosporidium spp., Cyclospora cayetanensis, Entamoeba histolytica, and Cystoisospora belli were the protozoans most frequently involved in recently reported waterborne and foodborne outbreaks and cases. Blastocystis hominis was reported to be the most widespread intestinal protozoan in humans, and two case reports indicated its pathogenic potential. Dientamoeba fragilis, Endolimax nana, and Pentatrichomonas hominis are also frequent but still require further investigation on their ability to cause illness. A progressive improvement in surveillance of protozoan infections and infection sources took place in developed countries where the implementation of reporting systems and the application of molecular diagnostic methods led to an enhanced capacity to identify epidemiological links and improve the prevention of foodborne and waterborne protozoan infections.

Screening and Structural Characterization of Heat Shock Response Elements (HSEs) in Entamoeba histolytica Promoters

Entamoeba histolytica (E. histolytica) exhibits a remarkable capacity to respond to thermal shock stress through a sophisticated genetic regulation mechanism. This process is carried out via Heat Shock Response Elements (HSEs), which are recognized by Heat Shock Transcription Factors (EhHSTFs), enabling fine and precise control of gene expression. Our study focused on screening for HSEs in the promoters of the E. histolytica genome, specifically analyzing six HSEs, including Ehpgp5, EhrabB1, EhrabB4, EhrabB5, Ehmlbp, and Ehhsp100. We discovered 2578 HSEs, with 1412 in promoters of hypothetical genes and 1166 in coding genes. We observed that a single promoter could contain anywhere from one to five HSEs. Gene ontology analysis revealed the presence of HSEs in essential genes for the amoeba, including cysteine proteinases, ribosomal genes, Myb family DNA-binding proteins, and Rab GTPases, among others. Complementarily, our molecular docking analyses indicate that these HSEs are potentially recognized by EhHSTF5, EhHSTF6, and EhHSTF7 factors in their trimeric conformation. These findings suggest that E. histolytica has the capability to regulate a wide range of critical genes via HSE-EhHSTFs, not only for thermal stress response but also for vital functions of the parasite. This is the first comprehensive study of HSEs in the genome of E. histolytica, significantly contributing to the understanding of its genetic regulation and highlighting the complexity and precision of this mechanism in the parasite's survival.

Diversity and Plasticity of Virulent Characteristics of Entamoeba histolytica

The complexity of clinical syndromes of amebiasis, caused by the parasite Entamoeba histolytica, stems from the intricate interplay between the host immune system, the virulence of the invading parasite, and the surrounding environment. Although there is still a relative paucity of information about the precise relationship between virulence factors and the pathogenesis of Entamoeba histolytica, by accumulating data from clinical and basic research, researchers have identified essential pathogenic factors that play a critical role in the pathogenesis of amebiasis, providing important insights into disease development through animal models. Moreover, the parasite's genetic variability has been associated with differences in virulence and disease outcomes, making it important to fully understand the epidemiology and pathogenesis of amebiasis. Deciphering the true mechanism of disease progression in humans caused by this parasite is made more difficult through its ability to demonstrate both genomic and pathological plasticity. The objective of this article is to underscore the heterogeneous nature of disease states and the malleable virulence characteristics in experimental models, while also identifying persistent scientific issues that need to be addressed.

Global burden and trends of the Entamoeba infection-associated diseases from 1990 to 2019: An observational trend study

BACKGROUND

Entamoeba infection-associated diseases (EIADs) in humans are a worldwide public health problem, but there is a lack of a global picture of EIADs, which is vital to prevention and control.

METHODS

We applied 2019 Global Burden of Disease (GBD) data collected from multiple sources at global, national and regional levels. The disability-adjusted life years (DALYs) with corresponding 95% uncertainty intervals (95% UIs) were extracted as the main measure of the burden of EIADs. The Joinpoint regression model was used to estimate the trends of age-standardised DALY rates by age, sex, geographical region, and sociodemographic index (SDI). Besides, a generalized linear model was conducted to analyze the influence of sociodemographic factors on the DALY rate of EIADs.

RESULTS

In 2019, there were 2,539,799 (95% UI 850,865-6,186,972) DALY cases attributable to Entamoeba infection, and the global age-standardised DALY rate of EIADs was 36.77/100,000 (95% UI: 12.03-90.49). Although over the past 30 years, the age-standardised DALY rate of EIADs presented significantly declining trends [average annual percent change (AAPC) = -3.79%, 95% CI: -4.05% - -3.53%], it has remained a heavy burden among the age group of <5 years (257.43/100,000, 95% UI: 67.73-676.78) and the low SDI regions (100.47/100,000, 95% UI: 32.27-249.09). The age-standardized DALY rate in high-income North America and Australia had an increasing trend (AAPC = 0.38%, 95% CI: 0.47% - 0.28% and 0.38%, 95% CI: 0.46% - 0.29%, respectively). Furthermore, the DALY rates in high SDI regions showed statistically significant increasing trends among the age groups of 14-49, 50-69 years and 70+ years, with AAPCs of 1.01% (95% CI: 0.87% - 1.15%), 1.58% (95% CI: 1.43% - 1.73%), and 2.93% (95% CI: 2.58% - 3.29%), respectively.

CONCLUSIONS

Over the past 30 years, the burden of EIADs has declined significantly. However, it has still caused a high burden in the low SDI regions and the age group of <5 years. At the same time, in adults and the elderly of the high SDI regions, the increasing trends of Entamoeba infection-associated burden should also be given more attention.