Studies on the most reactive purified antigen for immuno-diagnosis of hydatid disease.

Fourty hydatidosis patients and 36 patients with various parasitic diseases taken from Ain Shams University Hospitals and 15 normal controls as well were subjected to clinical examination, stool and urine examination, serological examination using indirect hemagglutination (IHA), counterimmunoelectrophoresis (CIEP) and enzyme-linked immunosorbent assay (ELISA) tests with crude and partially antigens for hydatidosis. Partial purification of crude hydatid fluid antigen abolished reactions in IHA test, reduced in ELISA or had no effect on cross reactions in the CIEP test. The crude antigen was more sensitive than the purified antigen in all tests applied. Using crude antigen, IHA (83%) was the most sensitive test followed by ELISA (68%) and then CIEP (60%) tests. In case of partially purified hydatid fluid antigen, CIEP was the most sensitive (58%) test with the purified peak I antigen followed by IHA test with peak III (48%) then ELISA with purified peak I (45%). In all serological tests applied, hepatic hydatidosis cases gave the highest reactions followed by cases of combined hepatic and pulmonary infections and then pulmonary cases alone.

Evaluation of crude and purified Toxocara canis antigens in serodiagnosis of human toxocariasis.

Three serological tests: Immunodiffusion (ID), Counterimmunoelectrophoresis (CIEP) and Enzyme-linked immunosorbent assay (ELISA) were used to study the role of crude adult worm antigen (CAWA) of Toxocara canis and each of its purified fractions in the serodiagnosis of human toxocariasis. Sensitivities of the three tests were lower in the ocular than in the visceral group, using different antigens. Purified fraction 1 showed more sensitive and specific reactions in the three tests, compared to CAWA or purified fraction 2 (P-F2) antigen. The other purified fractions (P-F3, P-F4 and P-F5) gave no positive reactions in any of the three tests. Using P-F1 antigen, ELISA was the most sensitive technique for diagnosis of both visceral and ocular toxocariasis followed by CIEP and then ID and the difference was statistically significant. However, CIEP was the most specific test followed by ELISA and lastly ID test. The ELISA test using Excretory-Secretory (E-S) larval antigen of Toxocara canis was less sensitive than the ELISA test using P-F1, although it was 100% specific. Thus, ELISA test using P-F1 is the test of choice for diagnosis of human toxocariasis, but when the specificity of a reaction is in doubt, CIEP test using the same antigen can be of value.

Laboratory study on the molluscicidal effect of Earth Tec: an environmentally responsible copper sulfate product.

Studies were carried out, under laboratory conditions to evaluate the molluscicidal activity of Earth Tec on Biomphalaria alexandrina snails, the intermediate host of Schistosoma mansoni. Earth Tec is an environmentally responsible copper sulfate product manufactured and marketed as an algicide/bactericide with an active ingredient form of copper ion (Cu++). A single application, of 1 ppm of copper equivalent, for 24 hours caused 100% mortality rate of the snails. Exposure for 48 hours to 1 ppm and 2 weeks to 0.25 ppm caused mortality rates of 84% and 100% respectively. It was concluded that this chemical compound is a promising molluscicide. Field studies are ongoing and will be published in due time.

Treatment of human scabies by sulfur and permethrin.

Scabies is one of the most important prevalent contagious disease caused by itch mite "Sarcoptes scabiei." Many effective scabiecides have been suggested and tried. They differ in their side effects since they are applied on diseased skin sometimes all over the body. In this paper, sixteen parasitologically proved human scabies were successfully treated by 5% sulfur precipitate and 2.5% permethrin. Application of sulfur for one week or 2 applications of permethrin followed by a third one a week later proved to be safe and effective. The one week course of sulfur and the third application of permethrin acts against any emerging immature stages of the mite.

The effect of praziquantel treatment on the liver functions, worm burden, and granuloma size using two drug regimen in murine Schistosoma mansoni infection.

The effect of single dose of praziquantel (400 mg/kg) or two doses on two consecutive days was studied in mice infected with S. mansoni. With the single dose there was improvement in the serum protein pattern towards pre-infection values & a transient rise in serum transaminases which soon declined to normal. Improvement was more evident after using two doses of praziquantel (P < 0.001). Worms were eradicated by 70%. 77% and 80% after the single dose and by 88%, 92% and 95% after two doses. Granuloma size was reduced by 50%, 54% and 60% after single dose and by 58% and 73% respectively after 10, 20, and 30 days from treatment.

Evaluation of cercarien hullen reaction (CHR) as a diagnostic test in chronic schistosomiasis and as a parameter for reinfection in acute cases.

CHR was evaluated as a serodiagnostic test in relation to stool analysis, rectal snip and indirect haemagglutination test (IHA) in 25 cases with chronic active mansonian schistosomiasis. Sensitivities of CHR, IHA, rectal snip and stool analysis, respectively, proved to be 68%, 48%, 84% and 52%. Rectal ship showed higher diagnostic efficacy 90% followed by CHR (77.5%), while IHA showed 67.5% diagnostic efficacy. To study CHR as parameter for pattern of reaction after treatment, 120 school children with acute mansonian schistosomiasis were examined CHR was done before and one month after treatment. These children were followed up for one year by stool examination. Results of CHR test after treatment showed that the children who were not reinfected gave the highest degree of reaction, while those of high reinfection showed decrease in reaction. This denotes that anticercarial antibodies may play a role in resistance to reinfection and CHR test could be used as parameter for reinfection in such cases.

Comparative study of three tests (indirect haemagglutination, direct agglutination, and indirect immunofluorescence) for detection of antibodies to Toxoplasma gondii in pregnant women.

Sera of 600 asymptomatic pregnant women were tested by IHAT for Toxoplasma antibodies. The positive reactors were further tested by IFAT and direct agglutination test (DAT). The prevalence of Toxoplasma antibodies was found to be 27.3% by IHAT, and 58.5% of those found positive were also positive by IFAT, while only 51.8% of them were positive by DAT with 71.34% degree agreement between both tests. So, IFAT was found to be more sensitive than DAT in reference to IHAT and is recommended as a confirmatory test for those found positive on screening by IHAT, DAT, compared to IFAT, gave 69.7% sensitivity and 73.5% specificity. Results support previous findings that IHAT, IFAT and DAT measure different antibodies of Toxoplasma gondii.

Comparative evaluation of antigens used in immunofluorescence (IFAT) antibody test for serodiagnosis of schistosomiasis.

The diagnostic value of antigens used in the IFAT for serodiagnosis of schistosomiasis has been evaluated. Cryosections of Schistosoma mansoni adults, formaline fixed cercariae and cryosections of infected liver, from gold hamster, which contained granuloma were used as antigens in this evaluation. The cryosections of adult worm were more reliable and more specific as an antigen for immunofluorescence (Diagnostic efficacy was 95.52%). The cercarial antigens gave the same results as the cryosection of adults. The IFAT using cryosection of infected liver contains granuloma was less reliable due to autofluorescence of eggs in the granuloma with negative sera (Diagnostic efficacy was 49.01).

Toxoplasmosis among pregnant women in Abha, Saudi Arabia.

The prevalence of toxoplasmosis in Abha, Saudi Arabia, was measured in pregnant women, by the indirect hemagglutination test. It was found to be still as high (31.6%) as reported previously, and the problem of toxoplasmosis in Saudi Arabia needs an organised health education and control program.

Parasitic infections and haemoglobin level among school children of different socioeconomic classes in Abha, Saudi Arabia.

A total of 717 school children from Abha region, from upper, middle and lower social classes (182, 405 & 130 respectively), were examined for parasitic infections and haemoglobin level. Giardia lamblia was found to be the most common intestinal parasite among children of all classes, Entamoeba histolytica followed among children of middle class, and Hymenolepis nana among those of lower one. Anaemia was more prevalent among parasitically infected children particularly the multi-infected ones of the lower social class.

Immunodiagnostics of visceral toxocariasis.

Twenty five suspected cases of visceral toxocariasis and 25 apparently healthy controls, were tested in four serological tests, namely precipitin absorption test (PAT), counter immunoelectrophoresis (CIEP), indirect fluorescent antibody test (IFAT), and enzyme linked immunosorbent assay (ELISA). Adult Toxocara worm antigen was used in PAT & CIEP as saline extract and as frozen sections (FS) in IFAT while the embryonated eggs (EE) were used as saline extract in ELISA and as a whole in IFAT. The percentages of positivity reported were 44% by PAT, 24% with CIEP, 52% with IFAT (EE), 48% with IFAT (FS), and 52% in the ELISA. In the apparently healthy control group, only one subject gave positive result with PAT, and ELISA at titres of 1/16 and 1/64 respectively. The EE antigen proved to be more sensitive than adult worm antigen, where it was used in IFAT & ELISA and gave the highest percentage of positivity and the highest titre (1/256 & 1/4096 respectively). It was noticed that the children below the age of 10 years, were statistically significant (P less than 0.05) by all tests except CIEP.

A preliminary survey of parasitic infections and nutritional status among school children in Riyadh, Saudi Arabia.

A total of 320 school children in the Model Institute of the Capital in Riyadh, were clinically and parasitologically examined. Thirty-five (10.94%) had intestinal parasites. Entamoeba coli (61.91%) was found more frequently among the commensals, while Giardia lamblia (28.57%) was the most common pathogenic parasite. All urines were parasite free. The low infection rate with Gardia could be explained by the good physical and nutritional status and better sanitary and living conditions.