Performance of loop-mediated isothermal amplification (LAMP) for detection of Schistosoma mansoni infection compared with Kato-Katz and real-time PCR.

The performance of loop-mediated isothermal amplification (LAMP) for detection of Schistosoma mansoni DNA from stool and urine samples in comparison with Kato-Katz and real-time polymerase chain reaction (PCR) was studied. After obtaining informed consent, 50 children participated in the present study and agreed to submit stool and urine samples. Stool samples were examined by Kato-Katz. Both real-time PCR and LAMP techniques were applied on stool and urine samples. The overall prevalence of S. mansoni was 46% in stool and urine samples as detected by the employed techniques, and 90% of cases had light infection intensity. The highest percentage of infection was diagnosed by real-time PCR (44%), followed by Kato-Katz (42%) and LAMP in the stool (36%), while the lowest percentages of infection were diagnosed by real-time PCR and LAMP in urine samples (24% and 14%, respectively). Kato-Katz, real-time PCR and LAMP showed 100% specificity where the sensitivity was 91.3%, 95.7% and 78.3%, respectively, in stool samples. Real-time PCR and LAMP showed lower sensitivity in urine samples. The LAMP assay is a promising technique for S. mansoni diagnosis in endemic countries of moderate and high-intensity infection. Yet, it needs further optimization, particularly in urine samples.

[Rupture of the round window membrane (author's transl)]. / Ruptur der Membran des runden Fensters (Klinische Studie)

Five cases of round window membrane rupture were described and under went surgery with gelfoam and/or adipose tissue repair. Short term post-operative follow-ups for a period of three to five months showed complete recovery of vestibular function yet only slight to moderate recovery of the cochlear. The clinical complex of sudden S.N. hearing loss, tinnitus with or without vertigo and ataxia is not uncommon and often presents a diagnostic problem. The patient is anxious to prevent further attacks and yearning for a cure from this relatively disabling condition. Among other causes, viral labyrinthitis and labyrinthine vascular occlusion have been blamed. R.W. membrane rupture, whatever is its underylying factor, as a cause of this clinical complex is well established. A well-planned management i.e. bed rest and/or properly timed exploratory tympanotomy with round window membrane tissue grafting may lead to a partial or total cure.

Evaluation of different means of control of snail intermediate host of Schistosoma mansoni.

Four water courses having the same conditions and snail density were chosen for this study. All methods were applied simultaneously in April. Snails were collected monthly to evaluate the malacological effect. A single application of 100 ppm dried A. maritima decreased the snail density significantly within one month. Snail density was maintained very low until the end of the year. Fresh Azolla pinnata applied in a dose of 280 ppm lowered snail density to a level intermediate between Ambrosia maritima and Bayluscide. Snail population began to build 5 months later. Bayluscide applied once at a dose of 1 ppm lowered significantly the snail density. This lowering was maintained for 4 months after which snails began to build up and remained high until the end of the study period. Clearing of vegetations was followed by abrupt lowering of snail density which was maintained for a period longer than that following Bayluscide and Azolla.

The pulmonary performance and airway reactivity in acute and chronic fascioliasis before and after triclabendazole treatment.

The pulmonary performance and airway reactivity were evaluated in 16 acute and 12 chronic fascioliasis patients before and after treatment with triclabendazole in a trial to clarify some underlying pulmonary changes which can explain the chest symptomatology that may accompany this intestinal fluke. Before treatment, the maximum voluntary ventilation was impaired in the acute and chronic cases. In the acute stage, the affection was in the small airways (as denoted by lower values of FEF75% compared to control), while in the chronic stage, the impairment was more generalized including not only the small and large airways (as shown by diminished FVC, FEV1, FEFmax, FEF25%, FEF50% and FEF75%) but also, the upper airway (as noticed by lower values of FIVC and FIF50% compared to the corresponding control values). By individual analysis of the dose response slopes (DRS), 37.5% of acute and 33.3% of chronic cases had bronchial hyperactivity. After triclabendazole treatment and cure of the patients, most of the pulmonary flow rates improved significantly compared to the pre-treatment values. Moreover, all cases regained normal bronchial reactivity and the DRS diminished significantly than during fascioliasis infection. It is concluded that, although the fluke doesn't have a cycle in the lung, yet it may have an impact on the pulmonary performance and airway reactivity which subsides greatly after treatment with triclabendazole.

Effect of triclabendazole on the tegument of Schistosoma mansoni: a scanning electron microscopic study.

The in vitro effect of Triclabendazole on the tegument of Schistosma mansoni was studied by means of scanning microscopy. Two different concentrations of drug were used (15 micrograms/ml and 75 micrograms/ml) and the worms examined after different exposure times (1 hr, 3 hrs, 24 hrs). It was found that, exposure of S. mansoni to Triclabendazole resulted in quick reactions: (1) The tegument was immediately destroyed after exposure in several places leading to the formation of defects in the surface of the worms. (2) The parasites contracted and became immobilized within one hour showing that the uptake of the drug was very rapid. (3) Triclabendazole caused 100% mortality after 24 hrs in the two concentrations. The ultrastructural changes were proportional to the concentration of drug and time elapsed.

Serum IgM. Does it relate to the level of chronicity in fascioliasis?

Serum IgM and IgG specific to human fascioliasis were reported to monitor prepatent and patent human infection respectively. Recently an assay measuring the antigen binding avidity of IgG antibodies was proved to be of value in identification of the stage of fascioliasis. The present study investigates the level of serum IgM in relation to avidity IgG, among acute and chronic Fasciola patients (using ELISA). Specific IgM antibody was detected in all acute and in 88% of chronic cases. IgM serum level was significantly higher in acute cases. IgG antibody was found in both acute and chronic cases but with no significant difference between the two groups. Regarding IgG avidity, it was found that acute cases had low IgG avidity index whereas chronic cases had significantly higher avidity. Four chronic patients had high IgM level and high IgG avidity. The egg counts as well were relatively high. The possibility of reinfection was considered in those cases.

The circumoval precipitin reaction in Fasciola. Detection of shell pores by scanning electron microscopy.

Precipitation reaction was detected around Fasciola eggs containing mature miracidia when they were incubated for 20 minutes with the sera of acute and chronic fasciolosis patients. The reaction was of the bleb type. The amount of blebs formed around the eggs was greater in case of acute than chronic fasciolosis. Scanning electron microscopy illustrated pores in the shell of Fasciola eggs. It is probable that the metabolic antigen passes through these pores leading to the positive circumoval precipitin reaction in cases of Fasciola infection. Antibodies specific to Fasciola excretory/secretory (E/S) egg antigens were not detected in the sera of Schistosoma cases.

IL-1, IL-4 production and IgE levels in acute and chronic fasciolosis before and after triclabendazole treatment.

IL-1 generation by mononuclear phagocytes, IL-4 production by Th2 lymphocytes and IgE levels in serum were measured in eight patients with acute fasciolosis and seven patients in the chronic stage of the disease before and after triclabendazole treatment. Results were compared with those of a control group of ten individuals. The monocytes and lymphocytes from patients with acute and chronic fasciolosis produced significantly lower levels of IL-1 and IL-4 respectively, particularly in the chronic phase of the disease, as compared to the control. A significant increase in IgE level in both acute and chronic fasciolosis was observed. The level was significantly higher in acute as compared to chronic cases. After treatment with triclabendazole IL-1, IL-4 and IgE levels moved towards the control indicating obvious improvement in the immunological responses of the patients.

Laboratory assessment of the molluscicidal activity of Commiphora molmol (Myrrh) on Biomphalaria alexandrina, Bulinus truncatus and Lymnaea cailliaudi.

The molluscicidal properties of the oil extract of Commiphora molmol (Myrrh) were tested against Egyptian snail species: Biomphalaria alexandrina, Bulinus truncatus and Limnaea cailliaudi. The impact of the extract on the egg cluches of B. alexandrina and L. cailliaudi was also evaluated. Snails and their eggs were exposed for 24 and 48 hr at 22-26 degrees C to various concentrations of the extract. The results showed different susceptibilities B. alexandrina showed higher LD50 and LD90 (155, 195 ppm) than B. truncatus (50, 95 ppm) and L. cailliaudi (50, 85 ppm) after 24 hr exposure. 100% mortality was obtained for the egg cluches of B. alexandrina and L. cailliaudi at concentrations of 100 ppm and 75 ppm respectively. Lower concentrations were needed to obtain the same results after 48 hr. The present laboratory studies demonstrated that Myrrh has a molluscicidal effect on the snail intermediate hosts, particularly on their eggs. Field studies are recommended.

Prevention of human fascioliasis: a study on the role of acids detergents and potassium permenganate in clearing salads from metacercariae.

Prevention of human fascioliasis could depend on clearing of the leafy salads from the metacercariae. The present work evaluated the role of some chemicals in detaching and killing this infective stage. It was observed that washing in running water for 10 minutes detached only 50% of the metacercariae. Citric acid in the concentration of (10 ml/L) commercial vinegar (120 ml/L), liquid soap (12 ml/L) and KMnO4 (24 mg/L) detached all metacercariae after 10 minutes exposure. The use of vinegar and KMnO4 is recommended: the first is lethal to other parasites in the vegetables, the second destroyed the metacercariae. Vegetable leaves were not softened and remained fresh.

The effect of Ambrosia maritima (Damsissa) on the viability of Lymnaea cailliaudi; an experimental study.

The present work aimed at studying the effect of Ambrosia maritima (Damsissa) on the viability of Lymnaea snails. Lymnaea snails used in these trials were acclimatized to laboratory conditions before use in the toxicity test. The snails were exposed to various concentrations (100-3000 mg/l) of dry powdered Damsissa, Ambrosia maritima was lethal to Lymnaea snails at concentration of 3000 mg/L after one day and at 100 mg/l after 14 days.