There has been an explosion of descriptions of new species of Cryptosporidium during the last two decades This has been accompanied by confusion regarding the criteria for species designation, largely because of the lack of distinct morphologic differences and strict host specificity among Cryptosporidium spp A review of the biologic species concept, the International Code of Zoological Nomenclature (ICZN), and current practices for Cryptosporidium species designation calls for the establishment of guidelines for naming Cryptosporidium species All reports of new Cryptosporidium species should include at least four basic components: oocyst morphology, natural host specificity, genetic characterizations, and compliance with the ICZN Altogether, 13 Cryptosporidium spp are currently recognized: C muris, C andersoni, C parvum, C hominis, C wrairi, C felis; and C cannis in mammals; C baileyi, C meleagridis, and C galli in birds; C serpentis and C saurophilum in reptiles; and C molnari in fish With the establishment of a framework for naming Cryptosporidium species and the availability of new taxonomic tools, there should be less confusion associated with the taxonomy of the genus Cryptosporidium The clarification of Cryptosporidium taxonomy is also useful for understanding the biology of Cryptosporidium spp, assessing the public health significance of Cryptosporidium spp in animals and the environment, characterizing transmission dynamics, and tracking infection and contamination sources

Cryptosporidium Taxonomy: Recent Advances and Implications for Public Health (Review)

Cryptosporidium and Giardia are important causes of diarrhoeal illness. Adequate knowledge of the molecular diversity and geographical distribution of these parasites and the environmental and climatic variables that influence their prevalence is important for effective control of infection in at-risk populations, yet relatively little is known about the epidemiology of these parasites in Africa. Cryptosporidium is associated with moderate to severe diarrhoea and increased mortality in African countries and both parasites negatively affect child growth and development. Malnutrition and HIV status are also important contributors to the prevalence of Cryptosporidium and Giardia in African countries. Molecular typing of both parasites in humans, domestic animals and wildlife to date indicates a complex picture of both anthroponotic, zoonotic and spill-back transmission cycles that requires further investigation. For Cryptosporidium, the only available drug (nitazoxanide) is ineffective in HIV and malnourished individuals and therefore more effective drugs are a high priority. Several classes of drugs with good efficacy exist for Giardia, but dosing regimens are suboptimal and emerging resistance threatens clinical utility. Climate change and population growth are also predicted to increase both malnutrition and the prevalence of these parasites in water sources. Dedicated and co-ordinated commitments from African governments involving “One Health” initiatives with multidisciplinary teams of veterinarians, medical workers, relevant government authorities, and public health specialists working together are essential to control and prevent the burden of disease caused by these parasites.

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Cryptosporidium and Giardia in Africa: current and future challenges

Every year, more than half a million children die due to diarrheal diseases. Recent studies have identified the most important etiologies of diarrheal disease are enterotoxigenic and enteropathogenic E. coli, Shigella spp., rotavirus, norovirus and Cryptosporidium spp. These etiologies are unsurprisingly characterized by a combination of high shedding, high infectivity, and transmissibility through multiple environmental reservoirs. The relative importance of the transmission routes is likely site-specific. So the impact of interventions, which typically target only one or two environmental reservoirs, is likely also site-specific. The factors influencing the transmission routes most important for diarrheal disease are complex, including – at a minimum – etiology of endemic disease; and water, sanitation, and hygiene infrastructure and practices. The site-specific nature – and complexity of transmission – helps explain the observed variation in impacts of water, sanitation, and hygiene interventions. It may also render efforts to estimate or quantify global means for interventions' impacts irrelevant. The theme of this Perspective is that greater reductions in diarrheal disease transmission in LMICs can be achieved by designing interventions to interrupt the most important environmental transmission pathways. Intervention choice should be informed by site-specific conditions, most notably: diarrheal etiology and existing water, sanitation, and hygiene infrastructure and practices. The theme is discussed through the lens of the characteristics of the most important diarrheal diseases (shedding, infectivity, growth, and persistence) and the general characteristics of environmental reservoirs (exposure pathways and fecal contamination). The discussion highlights when interventions – and combinations of interventions – will be most effective at reducing diarrheal disease burden.

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Environmental transmission of diarrheal pathogens in low and middle income countries

Giardia/giardiasis — A perspective on diagnostic and analytical tools

Methods for the detection of Cryptosporidium and Giardia: From microscopy to nucleic acid based tools in clinical and environmental regimes.

Giardia lamblia and Cryptosporidium parvum are recognized as the most common protozoan infections in Saudi Arabia. Microscopic examination of stool samples, either direct or concentrated, for the recovery of G. lamblia cysts and trophozoites and C. parvum oocysts is still the most commonly used for the diagnosis of both parasites. We compared the conventional parasitological techniques of iodine-stained wet mount for G. lamblia and Kinyoun's acid-fast for C. parvum against ImmunoCard STAT® Cryptosporidium/Giardia and real-time polymerase chain reaction (PCR) detecting the 18S rRNA gene of G. lamblia and conventional PCR detecting the same gene of C. parvum at a tertiary hospital in Dhahran, Saudi Arabia. Out of 148 stool samples, 19 and 12 true positives were identified for G. lamblia and C. parvum, respectively, using a composite reference standard. In this case, true positives and negatives were considered as those with at least two positive or negative results out of the three tests. Both ImmunoCard STAT! and PCR methods were more sensitive than the microscopic tests of a single stool specimen of 85.7 % (CI = 62.6–96.2 %) and 85.7 % (CI = 56.2–97.5 %) for G. lamblia and C. parvum, respectively. However, specificity of microscopic tests was higher than other techniques for both parasites. Although PCR seems to be most sensitive for both G. lamblia and C. parvum, its low specificity may render its superiority over other techniques. When a single stool sample is used for detection of G. lamblia and C. parvum, better results can be obtained when coupled with serological testing. Although PCR is the most sensitive method for the detection of both G. lamblia and C. parvum, its use requires attention in relation to the increased possible false positives.

Comparison of microscopy, rapid immunoassay, and molecular techniques for the detection of Giardia lamblia and Cryptosporidium parvum

Objectives
To study the performance of a single test using two fecal occult blood tests with colonoscopy for the detection of colorectal cancer (CRC) for the first time in Saudi Arabia to determine possible implications for the anticipated colorectal screening program.

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The sensitivity, specificity, predictive values, and likelihood ratios of fecal occult blood test for the detection of colorectal cancer in hospital settings

Background Worldwide, most of educational institutions have moved to online electronic learning methods because of the COVID-19 pandemic. On March 8, 2020, the Saudi Ministry of Education announced remote learning for public and private schools and universities as a preventive and precautionary measure to curb the spread of the coronavirus. The objective of this study was to explore the e-learning experience of the students of the colleges of health sciences with regard to the technical preparedness, academic achievements, e-learning advantages and limitations. A well-structured and validated questionnaire on a five-point Likert scale and open-ended questions about their e-learning experience was distributed to a heterogeneous purposive sample of the health sciences students in Saudi Arabian universities. Results Of the 1288 respondents, of various demographical features a relatively higher proportion of 58.2 % agreed that they had enough information about the online learning. However, the proportion who reported receiving adequate guidance, technical support, and having satisfactory hardware and internet access to online learning were 48.1 %, 42, and 35.4 %, respectively. Of all participants, 40.8 % agreed that they had gained a good understanding of their courses learning outcomes. Only 30.0 % agreed that the quality of the online teaching was similar to traditional classes and 56.1 % agreed that the online learning is unsuitable for the medical sciences studies. E-learning advantages mentioned were the flexible accessibility of the learning materials, time, effort, and money saving, acquiring and improving technical and self-learning skills, health safety, interaction without shyness, and better academic accomplishment. On the other hand, disadvantages and difficulties included inadequate tools to facilitate online learning, poor internet connection, lack of technological skills by the educators and students. In addition, there was inadequate or lack of practical classes, lack of a unified clear policy for the conduct of online classes and exams and grade distribution, limited online exam time. Conclusions The sudden shift to e-learning without prior preparedness has revealed some pitfalls that need to be adjusted. The initial findings were considered satisfactory for such a new experience for both learners and students. However, there is a great chance for improving and expanding the e-learning process.

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E- Learning experience of the medical profession's college students during COVID-19 pandemic in Saudi Arabia.

The epidemiological importance of the different routes of Toxoplasma gondii transmission is not known and depends largely on population behaviour and knowledge. This study was conducted to assess toxoplasmosis seropositivity and the related knowledge and preventive practices that are necessary for the prevention of the disease among pregnant women. All pregnant women attending antenatal clinic were tested for T. gondii immunoglobulins followed by a survey questionnaire that tested their knowledge and preventive practice. Statistical comparisons were made between the seropositive and negative ones. We determined a low to moderate seroprevalence of toxoplasmosis among pregnant women in Dhahran, Saudi Arabia as compared to many other parts of the world. The overall positivity rates of IgG and IgM against T. gondii among 400 pregnant women were 28.5 and 3%, respectively. 75.5% of the participants had never heard about toxoplasmosis and the associated risk factors. Lack of knowledge was associated with the higher risk of infection (OR = 4.04, p < 0.001). Keeping pet cats was not common and poorly associated with infections (OR = 1.15, p ≥ 0.64). Consumption of undercooked meat was reported frequently and only slight risk was associated with sheep/goat meat (OR = 1.39, p = 0.15). Eating outside the home at restaurants was reported for the first time to be related to a higher risk of infection (OR = 2.69, p < 0.001). Several possible risk factors were suggested through odds ratios calculation and overall knowledge of toxoplasmosis by pregnant women was poor. It is therefore vital to provide a formal education about toxoplasmosis risk factors to women of childbearing age.

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Toxoplasmosis seroprevalence in relation to knowledge and practice among pregnant women in Dhahran, Saudi Arabia.

Community face masking is possibly of great value in reducing COVID-19 transmission, especially when universally adopted with high compliance. The aim of this study is to investigate the knowledge, common misconceptions, barriers, and the compliance of the community with the use of face masks for the prevention of COVID-19. A validated questionnaire was administered to the participants through a web link by using various social media. The collected data were statistically analyzed for significant differences according to demographic variables. The average knowledge of face masks and their role in preventing COVID-19 transmission was 95.64%, with no differences among most of the demographical factors. Older groups and females demonstrated a better attitude towards wearing face masks than other groups did (p<0.001). Another significant difference in the participant's attitude was noticed between the various educational levels, employment, and nationality (p<0.001). Of the total respondents, 88.2% encouraged wearing face masks. Misconceptions about wearing face masks were very low. The frequency of wearing face masks at public places, workplaces, or social gatherings was 87.2%, 80.5%, and 47.5% respectively. There was a significant variation in the compliance with wearing face masks between the various groups based on age, gender, nationality, and employment status (p<0.001). The inconvenience in wearing face masks was reported by 36.3%. Face irritation and ear pain were reported by 70.2% and 43.5%, respectively. The inconvenience of wearing face masks with eyeglasses was reported by 44.3% of those wearing eyeglasses. In general, the study demonstrated a good attitude among participants towards wearing face masks. Although the respondents in the study were aware of the benefits of wearing face masks, the barriers may have decreased their desire to do so. These barriers include difficulty in breathing, discomfort, face irritation, and ear pain.

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Eidan M. Al Zahrani

Papers

Comparison of microscopy, rapid immunoassay, and molecular techniques for the detection of Giardia lamblia and Cryptosporidium parvum

The sensitivity, specificity, predictive values, and likelihood ratios of fecal occult blood test for the detection of colorectal cancer in hospital settings

E- Learning experience of the medical profession's college students during COVID-19 pandemic in Saudi Arabia.

Toxoplasmosis seroprevalence in relation to knowledge and practice among pregnant women in Dhahran, Saudi Arabia.

Community practice of using face masks for the prevention of COVID-19 in Saudi Arabia.