Comparison of Various Diagnostic Techniques for the Detection of Blastocystis Spp. and its Molecular Characterisation in Farm Animals in the United Arab Emirates.

Introduction: Blastocystis spp. is a common anaerobic intestinal parasite infecting humans and a diverse range of animals. The aim of the study was to compare different diagnostic methods for the detection of Blastocystis and survey the occurrence of its subtypes in farm animals, namely sheep, cows and camels, in Al-Ain, United Arab Emirates. Material and Methods: Ninety-seven faecal samples comprised of 69 from sheep, 12 from cows and 16 from camels were submitted to DNA extraction, PCR and sequencing. Blastocystis was screened for microscopically in 65 samples using direct wet-mount, modified acid-fast staining, trichrome staining and in vitro culture techniques. Results: Fifteen (15.5%) samples were positive by PCR, twelve of which were confirmed by sequencing. Using PCR as a comparison standard, the sensitivity and specificity of the direct wet-mount, modified acid-fast staining, trichrome staining and in vitro culture methods were 40.0% and 78.3%, 40.0% and 83.3%, 80.0% and 80.0%, and 80.0% and 76.7% respectively. Only culture and trichrome tests were significantly associated with PCR (odds ratio (OR) = 13.14; 95% confidence interval (CI): 1.35-127.4; P = 0.007 and OR = 16; 95% CI: 1.63-156.5; P = 0.003, respectively) with trichrome detecting more positive cases than in vitro culture. The subtype (ST)10 was the only one found in all 12 sequenced sheep isolates. Conclusion: The study corroborated previous data indicating that sheep are the natural hosts for ST10. No zoonotic subtypes nor mixed-subtype colonisation were found. The report also confirmed the superiority of trichrome staining in detecting Blastocystis spp.

Prevalence and Phylogenetic Analysis of Parvovirus (B19V) among Blood Donors with Different Nationalities Residing in Qatar.

Human parvovirus (B19V) is the causative agent of erythema infectiosum in children and is linked to a wide range of clinical manifestations. Studies related to B19V prevalence in the Middle East and North Africa (MENA) region and other parts of Asia are very scarce. The objectives of this study were to estimate the seroprevalence (anti-B19V IgM and IgG), the viremia rate (B19V DNA), and the circulating genotypes of B19V among blood donors in Qatar. METHODS: Donors' blood samples (n = 5026) from different nationalities, mainly from the MENA region and South East Asia, were collected from 2014-2016. Samples were tested for the B19V DNA using RT-PCR. Furthermore, 1000 selected samples were tested to determine the seroprevalence of B19V antibodies using enzyme-linked immunosorbent assay (ELISA). Genotyping was performed on 65 DNA positive samples by sequencing of nested PCR fragments (NS1-VP1u region, 927 nt). RESULTS: Only 1.4% (70/5026) of the samples had detectible B19V DNA in their blood. B19V DNA prevalence statistically decreased with age (p = 0.03). Anti-B19V IgG was detected in 60.3% (561/930) of the tested samples, while only 2.1% (20/930) were IgM-positive and 1.2% (11/930) were both IgM- and IgG-positive. B19V genotyping showed a predominance of Genotype 1 (100%). Sequence analysis of the NS1-VP1u region revealed 139 mutation sites, some of which were amino acid substitutions. CONCLUSION: Our results indicated a relatively high seroprevalence of B19V in Qatar. Most importantly, B19 DNA was detected among Qatari and non-Qatari blood donors. Therefore, blood banks in Qatar might need to consider screening for B19V, especially when transfusion is intended for high-risk populations, including immunocompromised patients.

Intestinal Parasite Detection in Assorted Vegetables in the United Arab Emirates.

OBJECTIVES: Consuming raw vegetables presents a considerable risk to the public and is the chief mode of transmission of intestinal parasites. We sought to assess the degree of parasitic contaminations on selected vegetables in the UAE. METHODS: A total of 218 fresh vegetable samples were collected randomly from different farms and local supermarkets between February 2017 and January 2018. After washing and centrifugation, the sediment was examined microscopically for parasitic forms. RESULTS: Protozoa cysts and helminths eggs were detected in 15.1% (33/218) of samples. The most detected parasites were Entamoeba complex (E. histolytica/E. dispar/E. moshkovskii) (30.3%), Entamoeba coli (18.2%), Trichuris trichiura (12.1%), Strongyloides stercoralis (12.1%), Ascaris lumbricoides egg (9.1%), Endolimax nana cyst and Enterobius vermicularis egg (6.1% each), and Giardia lamblia and Hymenolepis nana (3.0% each). We found no significant association between the vegetable type and the parasite occurrence (p > 0.050). Moreover, parasite incidence was independent of the vegetable type (p > 0.050). CONCLUSIONS: The study highlights the potential of raw produce serving as a major source of foodborne disease outbreaks and its role in the transmission of intestinal parasitic infections. Public education on the safe handling of raw vegetables is recommended.

Molecular Subtyping of Blastocystis from Diverse Animals in the United Arab Emirates.

The contribution of Blastocystis from non-human hosts to zoonotic transmission is only partly known. The objective of this study was to determine the distribution of Blastocystis genetic subtypes in different animal species in United Arab Emirates. A total of 114 stool samples were tested using PCR of the small subunit (SSU) rRNA gene and sequence analysis. Twenty-three Blastocystis-positive samples were identified. The following detection rates were observed: cattle, 22.7%; sheep, 63.6%; rabbits, 33.3%; rodents, 37.5%; reptiles, 21.2%. Four subtypes were identified in this study; ST4, ST10, ST14, and ST17; ST10 was isolated from sheep and cattle, corroborating previous data indicating that these are natural hosts for this subtype. Cases of mixed subtype colonization were also detected. Conspicuously, we found ST14 in rabbits. The discovery of ST17 in a squirrel indicates a novel host for this subtype. Furthermore, the discovery of ST4 in rodents suggests that these may serve as reservoir for human Blastocystis ST4 colonization. Six tortoises and one iguana were positive for Blastocystis. In conclusion, this is the first report of Blastocystis infection in various animals in the UAE. Apart from ST4, no potentially zoonotic subtypes were detected.

PREVALENCE OF CRYPTOSPORIDIUM SPP. AMONG ASYMPTOMATIC HEALTHY EXPATRIATE WORKERS IN SHARJAH, UNITED ARAB EMIRATES.

BACKGROUND: Epidemiological data on Cryptosporidium infections in the United Arab Emirates (UAE) is scarce. Therefore, the main objective of this study was to determine the prevalence of Cryptosporidium species among a community of expatriates in Sharjah, UAE working in different sectors, including the food industry, house maids and other domestic occupations. MATERIALS AND METHODS: One hundred and thirty four stool samples were collected from asymptomatic individuals presenting to the Sharjah Municipality Public Health Clinic (SMPHC) for screening of intestinal parasites for work permission purposes between 2009 and 2011. Demographic information such as age, sex, and country of origin was collected. Genomic DNA extracted from the stool samples were tested for Cryptosporidium species using real-time PCR (qPCR). RESULTS: Twenty-six individuals (19.4%) were positive for Cryptosporidium sp. by PCR. The infection rate was found to be highest in Afghan nationals (33%; 3/9) compared with the rest of the study population; yet, no significant association existed between nationality and infection rate. Moreover, no association was observed between infection rate and gender (χ2 = 2.439; P = 0.118), nor infection rate and age group (χ2 = 1.219; P = 0.544). CONCLUSION: Infection by Cryptosporidium sp. was common in the study group, and further studies are needed within the native Emirati population before any conclusions can be made about foreigners potentially transmitting the parasite. Furthermore, data provided in this study could help determine its public and veterinary significance particularly in outbreaks in the country.

First study in Qatar to reveal high Legionella counts in cooling towers.

Legionella spp. is transmitted from water to humans by aerosol-generating devices, including cooling towers (CTs). There have not been published reports about Legionella in these systems in Qatar. Ten CTs in Qatar University were sampled on a monthly basis. Bacteria were recovered from 90 water samples by filtration and concentration. Legionella DNA copy number (CN) was assessed by quantitative RT-PCR. Legionella DNA was detected in 100% of the samples. The bacterial counts ranged from 0.006 to 199.56 CFU/mL, and critical counts were found in 51 (56.7 %) samples. Moreover, 7 (7.8%) samples showed a count of more than 100 CFU/mL. The highest counts were found in the months of May and June. These results suggest that this organism is found in high number in tested CTs, presenting a potential health risk to the local population.

Prevalence and molecular profiling of Epstein Barr virus (EBV) among healthy blood donors from different nationalities in Qatar.

BACKGROUND: The Epstein-Barr virus (EBV) is the causative agent of infectious mononucleosis. EBV is highly prevalent lymphotropic herpesvirus and has been linked to several malignancies. Transmission is generally by oral secretions, but can be through blood transfusions and organ transplantations. This study aimed to determine the seroprevalence, viremia rates, and circulating genotypes of EBV in healthy blood donors in Qatar. METHODS: Blood samples from 673 blood donors of different nationalities residing in Qatar (mainly Qatar, Egypt, Syria, Jordan, Pakistan, and India) were collected and tested for anti-EBV capsid (VCA; IgG & IgM), nuclear (EBNA; IgG), and early (EA-D; IgG) antigens. Avidity testing was determined when active infection was suspected. DNA was extracted from the buffy coat and subjected to EBV-DNA quantification using qRT-PCR. Genotyping was performed using nested-PCR targeting EBV-EBNA2 gene, and phylogeny by sequence analysis of the LMP-1 gene. RESULTS: 97.9% (673/659) of the samples were seropositive as indicated by the presence VCA-IgG, while 52.6% (354/673) had detectible EBV-DNA. EBV seroprevalence and viremia rates increased significantly with age. Genotyping of 51 randomly selected samples showed predominance of Genotype 1 (72.5%, 37/51) as compared to genotype 2 (3.5%), and mixed infections were detected in 4% of the samples. Sub-genotyping for these samples revealed that the Mediterranean strain was predominant (65.3%), followed by B95.8 prototype and North Carolina strains (12.2% each), and China1 strain (6%). CONCLUSION: As a first study to evaluate EBV infection in highly diverse population in Qatar, where expatriates represent more than 85% of the population, our results indicated high seroprevalence and viremia rate of EBV in different nationalities, with genotype 1 and Mediterranean strain being predominant. Clinical significance of these finding have not been investigated and shall be evaluated in future studies.

Intestinal parasitic infections among expatriate workers in various occupations in Sharjah, United Arab Emirates.

Intestinal parasitic infections are prevalent throughout many countries. This study aimed to determine the prevalence of intestinal parasite carriers among 21,347 expatriate workers, including food handlers and housemaids attending the public health center laboratory in Sharjah, UAE. Stool sample collection was performed throughout the period between January and December 2013. All samples were examined microscopically. Demographic data were also obtained and analyzed. Intestinal parasites were found in 3.3% (708/21,347) of the studied samples (single and multiple infections). Among positive samples, six hundred and eighty-three samples (96.5%) were positive for a single parasite: Giardia lamblia (257; 36.3%) and Entamoeba histolytica/Entamoeba dispar (220; 31.1%), respectively, whereas mono-infections with helminths accounted for 206 (29.1%) of the samples. Infection rates with single worms were: Ascaris lumbricoides (84; 11.9%), Hookworm (34; 4.8%), Trichuris trichiura (33; 4.7%), Taenia spp. (27; 3.81%), Strongyloides stercoralis (13; 1.8%), Hymenolepis nana (13; 1.8%), and Enterobius vermicularis (2; 0.28%), respectively. Infections were significantly associated with gender (x2 = 14.18; p = 0.002) with males as the most commonly infected with both groups of intestinal parasites (protozoa and helminths). A strong statistical association was noted correlating the parasite occurrence with certain nationalities (x2= 49.5, p <0.001). Furthermore, the study has also found a strong statistical correlation between parasite occurrence and occupation (x2= 15.60; p = 0.029). Multiple infections were not common (3.5% of the positive samples), although one individual (0.14%) had four helminth species, concurrently. These findings emphasized that food handlers with different pathogenic parasitic organisms may pose a significant health risk to the public.

Association of Vitamin D receptor gene polymorphisms with metabolic syndrome and its components among adult Arabs from the United Arab Emirates.

AIMS: The aim was to investigate relationships of Vitamin D receptor gene (VDR) polymorphisms to the components of MetS among Arabs adult residing in the United Arab Emirates. METHODS: A cross-sectional study of 198 Arabs adult (50 males and 148 females). Serum levels of glucose, vitamin D, HDL-C, and TG, and blood pressure were measured. FokI, BsmI & TaqI genotyping of VDR were investigated using PCR-RFLP technique. RESULTS: Age of the participants was 21(9) years with a BMI of 26.8(7.8) kg/m2. About 15% had MetS with serum vitamin D levels of 25.5(18.2) nmol/L. VDR genotyping yielded: FokI: 57.1% FF and 38.9% Ff, BsmI: 29.8% bb and 51.5% Bb, while TaqI showed 39.4% TT and 43.4% Tt. The ff carriers had higher total cholesterol [174(12.4) mg/dl] than FF and Ff genotypes. Bb carriers showed higher BMI and LDL-C than BB and bb genotypes. In females, FokI VDR polymorphism showed significant association with systolic blood pressure (SBP) and F allele carriers were at higher risk of developing high SBP [x2=4.4, df1, OR=0.29 (95%CI: 0.087-0.98), p=0.035]. CONCLUSION: VDR gene polymorphisms were not associated with MetS, yet it may affect the severity of some of components of MetS, namely the association of BsmI with obesity, FokI and BsmI with dyslipidemia and FokI with SBP.

Prevalence of anelloviruses (TTV, TTMDV, and TTMV) in healthy blood donors and in patients infected with HBV or HCV in Qatar.

BACKGROUND: Anelloviruses (TTV, TTMV, and TTMDV) have been associated with non A-G hepatitis. The goal of the current study was to estimate the prevalence of these anelloviruses in Qatar. METHODS: A total of 607 blood samples (500 healthy donors, and 53 HBV-and 54 HCV-positive patients) representing different nationalities were tested for the presence of TTV, TTMV, and TTMDV DNA by nested PCR. RESULTS: Prevalence rates for the three viruses were high in all studied groups, and exceeding 95% in the HBV group (for TTV and TTMDV). Infection with more than one type of viruses was common and significant in most of the positive patients (p < 0.05) and ranging from 55.4% for TTV/TTMV and TTMV/TTMDV co-infections in the healthy group, to 96.3% for TTV/TTMV co-infections in the HBV group. Further, and as with most previous studies, no significant association was found between anelloviruses infections and age, nationality, or gender (p > 0.05) albeit the detection of higher infection rates among females and Qatari subjects. CONCLUSION: This was the first published study to look at prevalence of Anellowviruses in the Middle East. High prevalence rates of the three viruses in all studied groups was noted. Further studies are needed to explore and compare the different genotypes of these viruses in the region.

Prevalence and subtype distribution of Blastocystis in healthy individuals in Sharjah, United Arab Emirates.

Blastocystis is estimated to be one of the most common parasites of the intestinal tract of humans, comprising multiple subtypes (ST). Meanwhile, the distribution of Blastocystis ST in many communities and countries remains unknown. In the present work, we aimed to identify the prevalence of Blastocystis and the ST distribution in human stool samples collected from healthy expatriates from different geographical regions and residing in Sharjah, United Arabian Emirates (UAE). A total of 133 samples were screened and subtyped using partial small subunit ribosomal RNA gene sequencing. Fifty-nine (44.4%) samples were identified as positive. Among these, 39 were successfully sequenced and subtyped. The ST distribution was as follows: ST3, 58.9% (23/39); ST1, 28.2% (11/39); and ST2, 7.6% (3/39). No correlation between geographic origin and infection (χ(2)=11.006; P=0.528) nor gender and infection (χ(2)=1.264; P=0.261) was observed. The data were compared with those available for other Middle Eastern and North African neighboring countries. This study is the first to provide data concerning the prevalence of Blastocystis and the frequency of various STs in the UAE, confirming the absence of ST4 and the commonness of ST1, ST2, and ST3 in this geographical region.

Detection and phylogenetic analysis of human pegivirus (GBV-C) among blood donors and patients infected with hepatitis B virus (HBV) in Qatar.

Human Pegivirus (HPgV), formerly GB virus-C/Hepatitis G virus (GBV-C/HGV), collectively known as GBV-C, is widely spread and has been reported to be associated with non-A-E hepatitis. To our knowledge, no previous study was conducted about HPgV in Qatar. Thus, the objectives of this study were as follows: (i) to determine the rates of HPgV infection in Qatar among healthy blood donors and HBV-infected patients, and (ii) to determine the most predominant HPgV genotype in Qatar. A total of 714 blood plasma samples from healthy donors (612) and HBV-infected patients (102) were collected. RNA was extracted, reversed transcribed, and then subjected for HPgV detection by two round-nested PCR using primers amplifying a 208 bp of 5'-UTR of the HPgV. For genotyping, the 5'-UTR PCR products (from 25 randomly picked samples) were cloned and sequenced. The overall infection rate of HPgV in Qatar was 13.3%. There was no significant difference (P = 0.41) in the infection rates between healthy donor (13.7%) and in HBV-infected patients (10.7%). Moreover, we did not find any significant association between HPgV infection rates and nationality, sex, or age (P > 0.05). Sequence analysis of 40 5'-UTR PCR amplicons yielded the European genotype 2 as most predominant in Qatar, although other genotypes (5 and 7) were also present. Our results indicate that there is no strong correlation between HPgV infection rate, condition, nationality, age, and sex, and genotype 2 is most predominant in Qatar.

Detection and genotyping of torque teno virus (TTV) in healthy blood donors and patients infected with HBV or HCV in Qatar.

Torque Teno virus (TTV) has been associated with non A-G hepatitis. The goal of this study was to estimate the infection rates and genotypic characteristics of TTV in the State of Qatar. A total of 644 blood samples representing different nationalities: (i) Qatari (118) and (ii) non-Qatari (526) nationals (mostly from Arab and South Eeast Asia countries) were tested for the presence of TTV DNA by nested PCR. The majority (573) of the blood samples belonged to healthy blood donors, whereas 54 and 53 of the blood samples belonged to patients infected with hepatitis B virus (HBV) and hepatitis C virus (HCV), respectively. The results obtained showed that the TTV infection rates in the healthy blood donors, and those infected with HBV or HCV patients were 81.4, 90.75 and 84.9%, respectively. Significant association between TTV viremia and age, or nationality was observed. Sequence analysis of PCR fragments amplified from the 5'-untranslated region (5'-UTR) of all (531) TTV positive samples showed that 65.5% (348/531) of the PCR fragment sequences were classified into main genogroup 3, followed by main genogroups 5 (24%), 2 (5.8%), and 1 (4.7%). Genogroup 4 was not detected among the our studied subjects. Phylogenetic and pairwise analyses using sequences from TTV viremic samples also showed an overall close similarity to the main genogroup 3. In conclusion, there was no significant difference in the rates of TTV detection among Qataris and non-Qataris and several genotypes, mainly genotype 3, were isolated.

Detection and genotyping of TT virus in healthy and subjects with HBV or HCV in different populations in the United Arab Emirates.

TT virus (TTV) and TTV-like viruses (TTVLs) have been reported to be associated with non-A-E hepatitis. To determine the rate of infection and genotypic characteristics of TTV in the United Arab Emirates (UAE), a total of 449 serum samples representing different populations in the UAE and comprising healthy as well as patients positive for HBsAg and HCV were screened. National subjects (n = 200) and non-nationals residing in the UAE (n = 249) were tested by PCR. The results obtained showed that the rate of TTV infection in healthy nationals, and those with HBsAg or antibody to HCV were 34.9, 97.9, and 95.7, respectively, compared to 89.1% (115/129), 89.2% (66/74), and 84.8% (39/46), respectively, in non-nationals. Sequence analysis of the untranslated region (UTR) using 71 clones generated from the PCR products of eight serum samples from healthy individuals (four nationals and four non-nationals) showed that 83.1% of the TTV clones were classified into groups 1-4, whereas 16.9% into possibly new genotype(s). The analysis also revealed that healthy national subjects carried multiple viruses. Phylogenetic analysis of representative sequences revealed clustering of clones into at least five major groups. Also, when compared to reference genotypes (from GenBank), two of our clones belonged to two previously identified genotypes. Non-significant gender differences were seen in all ethnic groups studied (P > 0.05). In conclusion, the rate of TTV infection in the UAE nationals is significantly lower (P < 0.05) than that of the non-nationals and several genotypes were isolated with common multi-infections.

Molecular approaches to the study of Coccidioides immitis.

The study of the molecular biology of Coccidioides sp. is only just beginning. As the importance of coccidioidomycosis grows as a public health problem, our need for understanding of pathogenesis, immune responses, and improved antifungal therapy also increases in proportion. Tools have now become available to study gene manipulation in this pathogen and this will allow molecular approaches to be used. Genetic experiments will also be accelerated by the availability of the whole coccidioidal genome, expected to be made public in the spring of 2003 (see http://www.tigr.org/tdb/tgi/cigi/GenInfo.html). Thus, there seems to be several reasons to expect considerable progress in the coming years.