Prevalence and Risk Factors for Intestinal Protozoan Infections in Children with Cancer in Taif, Western Saudi Arabia.

BACKGROUND: Cancer is a category of diseases that cause an individual's immune system to become suppressed. In a case-control study, the current study aims to detect the frequency of intestinal parasites and related risk factors in children with cancer. METHODS: Stool samples were collected from 178 children with cancers (cases) and 150 cancer-free children (controls) who sought treatment for diarrheal episodes at nearby hospitals. Samples were processed by direct smear examination, concentration technique, permanent staining by Lugol's iodine, modified Ziehl-Neelsen, modified trichrome, and chromotrope 2R stains. RESULTS: The overall prevalence of intestinal parasites was 7.3% (24/328), with non-statistically significant differences between cases (7.8%; 14/178) and controls (6.6%; 10/150). Children with leukemia had a higher infection rate (9%; 9/100) than children with lymphoma (6.9%; 3/43) or solid tumors (5.7%; 2/35). Blastocystis sp. (3.3%) was the most common intestinal parasite found in cases, followed by Cryptosporidium sp. (2.2%), Giardia lamblia (1.6%), and Microsporidia sp. (0.5%). For all parasites, no statistical difference was found between the two groups. (p > 0.05). Male gender, young age, non-bottled water use, travel to parasite-endemic areas, living in an urban area, and infrequent hand washing were all associated with intestinal parasitosis, with non-statistical significance observed between the two groups. In children with cancer, intestinal parasites were found to be significantly associated with chronic (p = 0.04) and severe (p = 0.03) diarrhea. CONCLUSIONS: Children with cancer, particularly those with hematological cancers, should be screened for intestinal parasites on a regular basis and treated for their overall health.

Microsporidia infection in patients with autoimmune diseases.

Purpose: Microsporidium is a spore-forming intracellular parasite that affects a wide range of hosts including humans. The tumor necrosis factor alpha (TNF-α) plays a key role in the immunity to infection with microsporidia. Recently, the TNF-α antagonists have proven successful in treating variable autoimmune diseases. In the current study, we aimed to investigate the impact of using TNF-α antagonists as a therapeutic regimen in the prevalence of infections with microsporidia. Materials and Methods: Diarrheal patients with distinct autoimmune diseases (n = 100) were assigned to the study. Patients taking anti-TNF-α medications (n = 60) were allocated to Group 1A and those undergoing non-TNF-α inhibitor treatment (n = 40) to Group 1B. Furthermore, patients with diarrhea without autoimmune disorders (n = 20) were allocated as controls. Stool specimens, 3 per patient, were collected and microscopically examined for microsporidia spores. A microsporidia-specific stool polymerase chain reaction was used to confirm the microscopic findings. Results: Microsporidia infection was identified in 28.3% (17/60), 10% (4/40), and in 5% (1/20) of patients in Group 1A, Group 1B, and in the control group, respectively. Overall, infection was significantly high in cases compared to the controls and in patients receiving TNF-α antagonists compared to patients not given TNF-α inhibitors (P < 0.05). Finally, infection was significantly higher in cases treated with TNF-α antagonists for ≥2 months compared to cases treated for <2 months of duration (P < 0.05). Conclusion: There was a significant increase in microsporidia infection in autoimmune disease patients undergoing treatment with TNF-α antagonists, and the duration of treatment is one of the risk factors. The study highlights the importance of microsporidia testing in immunocompromised patients, particularly those undergoing treatment with anti-TNF-α drugs and emphasises the need for awareness among clinicians regarding this opportunistic parasite.

Association of toll-like receptors 2, 4, 9 and 10 genes polymorphisms and Helicobacter pylori-related gastric diseases in Saudi patients.

Purpose: Helicobacter pylori is one of the most prevalent human pathogens worldwide. However, the outcomes of H. pylori infection are markedly variable from asymptomatic mild lesion to malignant transformation. Many factors are suggested to influence these infection outcomes, including host immunity and genetic susceptibility. Toll-like receptors (TLRs) can recognise different microbial components and play an essential role in the mucosal immune response against H. pylori infection. Materials and Methods: The association between the common single nucleotide polymorphisms (SNPs) in the genes of TLR2, 4, 9 and 10 and H. pylori-related gastric diseases were investigated by molecular methods after the confirmation of H. pylori infection. The study included 210 patients in three groups; chronic gastritis (n = 90), peptic ulcer disease (PUD) (n = 75) and gastric carcinoma (n = 45). Results: The results showed a significant association between TLR4 SNPs (rs 4986790 and rs 4986791) and the presence of H. pylori infection, especially in chronic gastritis patient group. Furthermore, TLR9-rs352140 TT genotype was more prevalent among chronic gastritis patient group. TLR10-rs 10004195 TT genotype was found to be less prevalent among H. pylori-related chronic gastritis and PUD and was suspected to have a protective effect. TLR2 SNPs (rs3804099 and rs3804100) showed no significant statistical difference between H. pylori-infected patients and the controls. Conclusion: TLR genes polymorphisms may play a role in H. pylori infection susceptibility and may influence its outcomes; however, the ethnic and other factors may modify this effect.

High Frequency of Enteric Protozoan, Viral, and Bacterial Potential Pathogens in Community-Acquired Acute Diarrheal Episodes: Evidence Based on Results of Luminex Gastrointestinal Pathogen Panel Assay.

Infectious diarrhea is endemic in most developing countries. We aimed to investigate the protozoan, viral, and bacterial causes of acute diarrhea in Taif, Saudi Arabia. A cross-sectional prospective 1-year study was conducted on 163 diarrheal patients of various ages. Stool samples were collected, 1 per patient, and tested for 3 protozoa, 3 viruses, and 9 bacteria with the Luminex Gastrointestinal Pathogen Panel. Overall, 53.4% (87/163) of samples were positives (20.8% protozoa, 19.6% viruses, 2.8% bacteria, and 9.8% mixed). Rotavirus (19.6%), Giardia duodenalis (16.5%), and Cryptosporidium spp. (8.5%) were the mostly detected pathogens. Adenovirus 40/41 (4.2%), Salmonella (3%), Shiga toxin-producing Escherichia coli (3%), and Entamoeba histolytica (2.4%) were also detected. Norovirus GI/II, Vibrio cholerae, Yersinia enterocolitica, and Clostridium difficile toxin A/B were not detected in any patients. All pathogens were involved in coinfections except E. histolytica. Giardia (5.5%) and rotavirus (3%) were the most commonly detected in co-infections. Enterotoxigenic E. coli (2.4%), Campylobacter spp. (2.4%), E. coli 0157 (1.8%), and Shigella spp. (1.2%) were detected in patients only as co-infections. Infections were more in children 0-4 years, less in adults <40 years, and least >40 years, with statistically significant differences in risk across age groups observed with rotavirus (P<0.001), Giardia (P=0.006), and Cryptosporidium (P=0.036) infections. Lastly, infections were not significantly more in the spring. This report demonstrates the high burden of various enteropathogens in the setting. Further studies are needed to define the impact of these findings on the clinical course of the disease.

LYMPHO-PROLIFERATIVE RESPONSES TO VARIOUS FASCIOLA HEPATICA WORM'S ANTIGENS: AN IN VITRO STUDY.

Fascioliasis is an important zoonotic disease with approximately 2-4 million people infected worldwide and a further 180 million at risk of infection. F. hepatica can survive within the bile ducts for many years through its ability to suppress the host immunity with Fasciola cathepsin L1 cysteine protease and Glutathione S transferase playing an important role. The aim of the present study is to investigate the in vitro lympho-proliferative responses of hepatic hilar lymphocytes (HLN) of infected sheep in response to different F. hepatica antigens. The suppressive effects of Fasciola excretory/secretory (ES) and tegument (TEG) and their fractions were also investigated. Our results showed that both ES and TEG had significant suppressive effects on lympho-proliferation, up to 74% and 92%, respectively. When these antigens were fractionated, fraction 3 (MW of >10000-30000) of both ES (64%) and TEG (59%) in addition to fraction 4 (MW of ≤ 10000) of TEG (38%) inherited the suppressive effects. Identification of the potential molecule(s) with such suppressive effects on lymphocytes in TEG fraction 4 could reveal vaccine candidates.

DNA extraction from protozoan oocysts/cysts in feces for diagnostic PCR.

PCR detection of intestinal protozoa is often restrained by a poor DNA recovery or by inhibitors present in feces. The need for an extraction protocol that can overcome these obstacles is therefore clear. QIAamp® DNA Stool Mini Kit (Qiagen) was evaluated for its ability to recover DNA from oocysts/cysts directly from feces. Twenty-five Giardia-positive, 15 Cryptosporidium-positive, 15 Entamoeba histolytica-positive, and 45 protozoa-free samples were processed as control by microscopy and immunoassay tests. DNA extracts were amplified using 3 sets of published primers. Following the manufacturer's protocol, the kit showed sensitivity and specificity of 100% towards Giardia and Entamoeba. However, for Cryptosporidium, the sensitivity and specificity were 60% (9/15) and 100%, respectively. A series of optimization experiments involving various steps of the kit's protocol were conducted using Cryptosporidium-positive samples. The best DNA recoveries were gained by raising the lysis temperature to the boiling point for 10 min and the incubation time of the InhibitEX tablet to 5 min. Also, using a pre-cooled ethanol for nucleic acid precipitation and small elution volume (50-100 µl) were valuable. The sensitivity of the amended protocol to Cryptosporidium was raised to 100%. Cryptosporidium DNA was successfully amplified by either the first or the second primer set. When applied on parasite-free feces spiked with variable oocysts/cysts counts, ≈ 2 oocysts/cysts were theoretically enough for detection by PCR. To conclude, the Qiagen kit with the amended protocol was proved to be suitable for protozoan DNA extraction directly from feces and support PCR diagnosis.