Storage Mite Infestation of Dry-Stored Food Products and Its Relation to Human Intestinal Acariasis in the City of Minia, Egypt.

Initial data on the prevalence of storage mites in dry-stored food products and estimates of the presence of mites in human stool in the city of Minia, Egypt are provided. In total, 847 samples were collected randomly from houses and retail stores between March 2017 and February 2018. In addition, 1,000 human stool samples were collected for the detection of the presence of mites. Mites were extracted from 285 of 840 (33.9%) samples, and mite contamination was found to be most prevalent in wheat flour (73.3%). In total, 11 mite species belonging to six families were identified, with the pest species Tyrophagus putrescentiae (Schrank) (Acari: Acaridae) (TP) being the most prevalent (91.2% of samples). The seasonal density distribution showed the highest storage mite density in March-April, followed by October, and the lowest in January. In addition, mites were detected in 87 (8.7%) human stool samples, with significant associations between certain occupations and some personal characteristics. Therefore, more attention needs to be paid to intestinal acariasis arising from mite infestation of dry-stored food products.

Prevalence of Cryptosporidium species isolated from diarrheic children in Makkah, Saudi Arabia.

Cryptosporidiosis has been identified as a significant underlying cause of morbidity and mortality worldwide. Studies in high and low income countries have recognized the importance of Cryptosporidium as a cause of diarrhea. The objectives of the current study were to determine the prevalence rate and genotypes of Cryptosporidiumin in diarrheic children in Makkah Region. A total of 1,380 fecal samples were collected from children aged up to 14 years attending 3 major hospitals of Makkah between March 2015 and March 2016. Stool collected were subjected to direct microscopic examination and crypto antigen detection using ImmunoCard STAT, Cryptosporidium/Giardia rapid test. Part of each positive stool sample was kept frozen at -20ºC for molecular characterization. Initial screening by immunochromatographic detection kit revealed 23 positive cases. PCR was performed for positive cases by amplification of a piece of the gene encoding the small (18S) subunit of rRNA producing a 435-438 bp product. Cryptosporidium genotyping was performed by RFLP analysis of PCR products. Genotyping revealed 18 cases C. hominis genotype, 4 cases C. parvaum genotype and one sample failed to be amplified. The data revealed a higher incidence of the common human species C. hominis (81.8%). The detection of both C. hominis and C. parvaum genotypes point to the possibility of both anthroponotic and zoonotic transmission routes occurring in Makkah region. Further studies are needed to verify the subgenotypes of Cryptosporidium to elucidate the real transmission modes and hence plan for effective control strategies.

Specific anti-Toxoplasma antibodies in relation to infection and reinfection using different infective stages.

The possibility of rat re-infection with different Toxoplasma gondii stages was studied in this work. Two groups of rats were infected with either intra-peritoneal injection of 1000 trophozoites of virulent Toxoplasma strain or 1000 oocysts through oral routes. IgA, IgM and IgG were detected 15, 30, 60 and 120 days post infections. IgA and IgM appeared as early as 15 days post infection but declined afterwards. IgA antibody response was more prominent with oocyst infection and IgM was more prominent with tachyzoite infection with insignificant statistical difference. On the other hand, IgG started to increase 60 days post infection, then increased gradually till the end of the experiment (120 days). The primary orally infected rats were either re-infected orally with oocysts or intra-peritoneal trophozoites and re-examined after 15 and 120 days for the same immunological parameters. Those rats which primary infected with intra-peritoneal trophozoites were re-examined after oral infection with oocysts or injection of trophozoites intra-peritoneal. The level of IgA and IgM in one rat of group A and 2 rats of group B were significantly increased and this occurred in presence of anti-Toxoplasma IgG from the primary infection. In this study, the rats were lab-bred so, the factors affect the immune system could be under control, also strain variability was excluded as the infection was only by one strain, and as the IgG level was high, these rats were presumed to be immune from the primary infection. So, the rats which became positive after challenge most probably re-infected.

Sensitive and specific assay for detecting circulating antigens in individuals infected with Schistosoma mansoni.

Monoclonal antibody 128C3/3/21 in an antigen-capture ELISA was used to detect circulating antigen in individuals infected with Schistosoma mansoni. This antibody recognizes a carbohydrate epitope expressed on the major group of acidic egg glycoproteins and on glycoproteins and glycolipids in all other stages of parasite development. The overall sensitivity of the assay was 78%, with a sensitivity of 100% for patients excreting >100 egg/g feces (EGF) and 72% for those excreting <100 EGF. By increasing the degree of antibody biotinylation, the authors have now achieved sensitivities of 92.4% overall and 82% for those excreting <100 EGF. A direct increase in the mean level of circulating antigen was found with increasing egg counts. The difference between those excreting >100 EGF (53 individuals) and those excreting <100 EGF (39 cases) was statistically significant (P<0.01). None of the control sera (23 uninfected individuals and 16 patients infected with other parasites) had circulating antigen levels >80 ng/ml. Thus, the test specificity was >99%. The test accuracy was 94.7%, the positive predictive value 100%, and the negative predictive value 84.8%.

Circulating filarial antigens for monitoring the efficacy of ivermectin in treatment of filariasis.

Seventy-three asymptomatic bancroftian filariasis patients with positive microfilaria in their blood films were included. The patients were randomly divided into 2 groups: ivermectin group (50 cases) given 2 doses each of 100 ug/kg body weight, 3 months apart, and 23 cases had 2 doses of placebo. The study was run blindly for one year. The initial mean microfilaria (MF) count was 111/ml. At 3 months after ivermectin therapy, mean MF became 7.8/ml and 24% of ivermectin treated cases had no detectable MF (P <0.05). At 6, 9 and 12 months, the mean MF count became 4.1, 6.5 and 11/ml with amicrofilaria in 54%, 42% and 40% of treated cases respectively (P <0.05). On the other hand, no statistically significant change in the mean MF count in placebo group was detected. The routine laboratory investigations were unchanged or slightly improved at 3 and 6 months. Side effects after the first dose of ivermectin were mild fever in 16% and weakness in 20%. None was recorded after the second dose. Circulating filarial antigens could be detected in 66% of cases before treatment, as all cases with high microfilaremia had positive antigenemia. The mean antigen level started to decline significantly after 9 months post treatment. At the end of the study (one-year), all negative microfilaremic cases had negative antigen levels, indicating that detection of antigen in-patients sera is a very good indicator of cure and efficacy of the drug.