Key cytokines and hematological parameters in patients with uncomplicated falciparum malaria in Hodeidah, Yemen

Immunity to malaria has a major role in controlling disease and pathogenesis with cytokine production being involved in almost every phase of the immune response. The present study aimed to assess hematological variables and to measure plasma levels of TNFα, IFNγ and IL10, their ratios, and their relation to parasitemia among patients with uncomplicated falciparum malaria in Hodeidah, Yemen. Forty patients with uncomplicated P. falciparum monoinfection and 40 healthy age and sex-matched controls were enrolled in the study. Parasitological diagnosis was confirmed, and parasite density was estimated. Plasma cytokine levels, hematologic parameters, and the presence of gametocytes were determined. Results revealed higher TNFα, IFNγ and IL10 in patients than in controls. A relatively higher IL10 production was demonstrated by the significantly lower TNFα/IL10 and IFNγ/IL10 ratios in patients than in controls. TNFα and IL10 correlated positively with parasite density. Lower Hb levels, RBC, lymphocyte and platelet counts, and higher neutrophil and reticulocyte counts were observed in patients compared to controls. Reticulocyte count was higher and IFNγ level was lower in the presence of gametocytes. Conclusively, uncomplicated falciparum malaria is associated with the ability to regulate the production of pro-inflammatory and anti-inflammatory cytokines. This mediates parasite clearance while simultaneously avoiding severe pathology.

Remarkable histopathological improvement of experimental toxoplasmosis after receiving spiramycin-chitosan nanoparticles formulation

The present study investigated the anti-Toxoplasma effect of chitosan nanoparticles [CS NPs], spiramycin, spiramycin co-administered with metronidazole and spiramycin-CS NPs formulation on the parasite burden and histopathological changes in the liver, spleen and brain in experimentally infected mice. Seventy male Swiss albino mice were classified into seven equal groups: healthy control (I), infected untreated control (II), infected group receiving CS NPs (III), spiramycin administered infected group (IV), infected group receiving spiramycin-metronidazole (V), infected receiving 400 mg/kg spiramycin-CS NPs (VI) and infected treated with spiramycin-loaded CS NPs 100 mg/kg (VII). All groups were inoculated intraperitoneally with 2500 T. gondii tachyzoites RH strain except the healthy control group. All groups were sacrificed on the 8th day after infection. Density of the parasite and histopathological examination of the liver, spleen and brain of all treated mice revealed reduction in the mean tachyzoites count as well as decreased inflammation, congestion and necrosis within tissue sections. Spiramycin-loaded NPs displayed the highest significant reduction in the pathological insult tailed by spiramycin-metronidazole and CS NPs. In conclusion, spiramycin-loaded CS NPs showed a promising synergistic combination in the treatment of the histopathology caused by toxoplasmosis.

Detection and molecular identification of Blastocystis isolates from humans and cattle in northern Egypt

Blastocystis is one of the less well-understood waterborne protozoa of medical and veterinary importance. The present study aimed to detect, identify, and subtype Blastocystis in cattle and humans in northern Egypt and to investigate the potential for zoonotic transmission. Fecal samples were collected from 136 humans (68 in contact with animals and 68 no animal contact) and 190 cattle from a rural area in Kafr El-Sheikh Province, Egypt. All samples were microscopically examined by direct wet mount technique and cultured in Jones' medium. Genomic DNA was extracted from positive cultures. A region of the Blastocystis small subunit ribosomal ribonucleic acid (SSU rRNA) gene was amplified using PCR. Blastocystis subtypes were identified by sequencing of the amplified SSU rRNA gene. The relatedness of sequence types obtained in this study and others submitted in GenBank was compared according to their genetic relatedness. Out of 136 human and 190 cattle samples, Blastocystis was detected in 53 (38.9%) and 37 (19.4%), respectively using either culture or direct wet mount. Blastocystis SSU rRNA gene was amplified in 55 samples (32 humans and 23 animals). Six subtypes were identified (STs 1-3 in humans and ST4, ST10 and ST14 in cattle) and were distinguishable with inter (up to 0.075) and intra (up to 0.024) subtype variations. A close phylogenetic relationship between human and animal isolated STs 1-4 was demonstrated. To the best of our knowledge, this is the first study to investigate the the potentiality for zoonotic transmission of certain Blastocystis subtypes in northern Egypt.

Hematological Parameters and Key Cytokines in Patients With Uncomplicated Falciparum Malaria in Hodeidah, Yemen.. [DOI: 10.21203/rs.3.rs-695903/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Immunity to malaria has a major role in controlling disease and pathogenesis with cytokine production being involved in almost each phase of the immune response. The present study aimed to assess hematological variables and to measure plasma levels of TNFα, IFNg and IL10, their ratios, and their relation to parasitemia among patients with uncomplicated falciparum malaria in Hodeidah, Yemen. Forty patients with uncomplicated P. falciparum monoinfection and 40 healthy age and sex matched controls were enrolled in the study. Parasitological diagnosis was confirmed, and parasite density estimated. Hematologic parameters, the presence of gametocytes, and plasma cytokine levels were determined. Results revealed lower Hb levels, RBC, lymphocyte and platelet counts and higher neutrophil and reticulocyte counts among patients compared to controls. TNFα, IFNg and IL10 were higher in patients than controls. A relatively higher IL10 production was demonstrated by the significantly lower TNFα/IL10 and IFNg/IL10 ratios in patients than controls. TNFα and IL10 correlated positively with parasite density. Reticulocyte count was higher and IFNg level was lower in the presence of gametocytes. Conclusively, uncomplicated falciparum malaria is associated with the ability to regulate the production of the pro-inflammatory and anti-inflammatory cytokines. This mediates parasite clearance while simultaneously avoiding severe pathology.

Detection and Molecular Identification of Cryptosporidium Species Among Children with Malignancies

BACKGROUND

Cryptosporidiosis represents a major health problem worldwide particularly among children. Its diagnosis is still difficult and demands sensitive methods. In Egypt, there is little documentation of infection among children with malignancies. This work was designed to study the infection rate of Cryptosporidium among children with malignancies, compare the performance of modified Ziehl-Neelsen (MZN) stain with nested polymerase chain reaction (PCR) and identify the species subtypes of positive cases.

METHODS

The study was conducted on 100 children with malignancies (leukemia, lymphoma and solid tumors), below 10 years of age, from El-Shatby hospital, Alexandria University. After obtaining the informed consent, their stool samples were collected and examined microscopically following MZN stain for the diagnosis of Cryptosporidium spp. All samples were then subjected to nested PCR. Restriction fragment length polymorphism (RFLP) targeting the Cryptosporidium oocyst wall protein (COWP) gene was applied to positive cases, using restriction enzyme RsaI for digestion of nested PCR products.

RESULTS

Out of the 100 examined children, MZN detected higher positive cases compared to nested PCR. Six cases (6%) were diagnosed positive by MZN stain, three of which (3%) were concordantly positive by nested PCR. All positives were among children with acute lymphoblastic leukemia (ALL). Fair agreement was found between the two tests (K = 0.36). Genotyping results revealed that positive samples were of Cryptosporidium parvum (C. parvum) type II.

CONCLUSIONS

Low Cryptosporidium infection rate was detected among children with malignancies. MZN diagnosed more positive cases compared to nested PCR. C. parvum type II was the identified species among the examined children. Further optimization of PCR steps is needed.

Therapeutic efficacy of mebendazole and artemisinin in different phases of trichinellosis: a comparative experimental study

The present work aimed at studying the efficacy of mebendazole (MBZ) compared to artemisinin (ART) for the treatment of trichinellosis at various phases of infection. Seventy Swiss albino mice were orally infected by 300 Trichinella spiralis (T. spiralis) larvae. Mice were divided into infected untreated control group and infected groups treated with 50 mg kg-1 MBZ and 300 mg kg-1 ART for three and five consecutive days, respectively, at the enteral phase [2-4 days post infection (PI)], invasive phase (10-12 days PI) and encapsulated phase (28-30 days PI). All mice were sacrificed 35-42 days PI. MBZ and ART revealed a significant decrease in mean larval counts and increase of larval per cent reduction (LR %) when treatment was initiated during the enteral phase compared to the other phases. MBZ showed significantly higher LR % (99.7, 83.95 and 89.65%) than ART (80.58, 67.0 and 79.2%) when administered at the three infection phases. Histopathological study showed a decrease in the number of encysted larvae, their surrounding cellular infiltrates and increased regenerative muscles in all treated mice. In conclusion, ART possesses a substantial anthelmintic activity against T. spiralis infection in mice both at the enteral and encapsulated phases, yet, significantly lower than MBZ.

Intestinal schistosomiasis among preschool and school-aged children in a rural setting near Alexandria: initiative for elimination

OBJECTIVE

To assess the status of intestinal schistosomiasis among preschool-aged (PSAC) and school-aged children (SAC) and to compare the efficacy of praziquantel (PZQ) in both groups.

METHODS

The study was conducted on 400 children; 103 PSAC and 297 SAC. Diagnosis of Schistosoma mansoni was based on triplicate Kato-Katz thick smears from a single stool sample. To identify the missed cases by Kato-Katz, 120 randomly selected negative cases (38 PSAC and 82 SAC) were screened by real-time PCR. All S. mansoni-positive cases by Kato-Katz were treated by crushed PZQ tablets. Four weeks after treatment, the cure rate was assessed by Kato-Katz smears and real-time PCR.

RESULTS

The prevalence of S. mansoni with Kato-Katz was 7.8% among PSAC and 7.4% among SAC. Most of children (63.3%) had light-intensity infection. The cure rate was 100% among PSAC by both techniques, and 91%, and 77.2% among SAC by Kato-Katz and real-time PCR, respectively. In the 120 stool samples screened by real-time PCR, S. mansoni prevalence was 25%; 15.8% and 29.3% were among PSAC and SAC respectively. Treated cases showed a lower range of Ct values than untreated cases. Two melting temperature ranges (Tm = 83-87°C and 89-93°C) were recognised among uncured cases which may point to S. mansoni genetic variability.

CONCLUSION

Continuous monitoring and inclusion of PSAC in schistosomiasis control programmes are crucial. Real-time PCR and other molecular tools are recommended for evaluation of the true prevalence, assessment of cure and further studies on genetic diversity.

Intestinal parasites among humans and their livestock animals in a rural community in Gharbia governorate, Egypt

Our objective was to study the prevalence of intestinal parasitic infections among humans and their contact livestock animals in a rural community in Gharbia governorate, Egypt. The collected human and livestock animal fecal samples were examined by formol ether sedimentation technique and modified Ziehl-Neelsen stain. Human samples were further examined by the Kato-Katz technique. The total prevalence of intestinal parasites in humans was 52.3%; 7.3% helminths and 45% protozoa. Regarding animals, 29% of livestock animals had protozoan parasites and no helminths were detected. Results revealed that risk factors including drinking tap water and attendance of nurseries, affected the rate of parasitic infection among humans. The infection rate of protozoa was significantly higher among humans (1.5 times) as compared to animals.

Comparison among FLOTAC, Kato-Katz and formalin ether concentration techniques for diagnosis of intestinal parasitic infections in school children in an Egyptian rural setting

The study aimed to compare the diagnostic performance of the Kato-Katz, formalin ether concentration method (FECM) and FLOTAC using Sheather's sugar solution (FS1), saturated sodium chloride (FS2) and zinc sulfate (FS7) for the diagnosis of intestinal parasites among school children, focusing on Schistosoma mansoni. Ninety fecal samples were examined using the above mentioned techniques. The overall infection rate was 87.7%. Concerning protozoa, FLOTAC (FS1 and FS2) and FECM detected nearly equal infection rates (43.3% and 44.4%, respectively) with very good agreement. Kato-Katz diagnosed the highest helminthic infection rate (57.8%) followed by FLOTAC FS7 (44.4%) and FECM showed the lowest helminthic infection rate (27.7%). As for S. mansoni, Kato-Katz showed an infection rate of 38.8% vs FLOTAC (22.2%) and FECM (11.1%). The three techniques detected the same infection rate (11.1%) with egg counts more than 72 eggs/gram of feces. The FLOTAC sensitivity and accuracy for the diagnosis of protozoa were 97% and 99%, respectively. Regarding helminths diagnosis, FLOTAC technique showed higher sensitivity (77%) and accuracy (87%) compared to FECM (48% sensitivity and 70% accuracy). Therefore, FLOTAC can be used synchronously or in replacement to other diagnostic techniques. This can strategically impact future control programmes of intestinal parasitic infections in limited resources settings.

A study on positive school children as indicators of schistosomiasis status in their families

This study aimed to evaluate schistosomiasis positive school children as indicators of infection in their families. Four hundred and sixteen stool samples of children from two primary schools were examined microscopically for Schistosoma mansoni (S. mansoni) after Kato-Katz. Equal numbers from families of schistosomiasis positive and negative school children were examined by Kato-Katz. Circulating cathodic antigen (CCA) cassette test was performed on 100 Kato-Katz negative children to detect missed S. mansoni cases if any. S. mansoni infection rates among the primary school children were 15.3% and 1.6% in high and low prevalence schools respectively. Sixty five percent of school children had light intensity infection. Family members were either negative or exhibited a prevalence rate as low as 5-6% whether related to positive or negative children. A higher infection rate of S. mansoni was detected by the CCA test compared to the Kato-Katz. Conclusively, children can be good indicators of their particular families in areas of limited resources and low endemicity. Efforts are required to permit large scale use of CCA cassette test.

Evaluation of two doses of triclabendazole in treatment of patients with combined schistosomiasis and fascioliasis

To determine the safety and efficacy of 2 consecutive doses of triclabendazole (TCBZ) in the treatment of Schistosoma mansoni infection in human cases infected with both S. mansoni and Fasciola sp., we conducted a field survey involving 6314 individuals from 15 villages. The overall prevalence of schistosomiasis alone was 15.8%, of fascioliasis alone 2.2%, and of combined infection 0.7%. Treatment with 2 doses of TCBZ was given to the 49 cases with combined infection. Eight weeks after treatment, the cure rate was 96% for fascioliasis and was 32.7% for schistosomiasis. All schistosomiasis cases cured had a low intensity infection. Liver function tests done before treatment and 8 weeks after substantiate the safety of 2 doses of TCBZ given to those with combined infection. Administration of TCBZ should precede praziquantel in treatment of combined infection, however TCBZ cannot be recommended for infection with S. mansoni alone.

Ineffectiveness of myrrh-derivative Mirazid against schistosomiasis and fascioliasis in humans

The present study assessed the schistosomicidal and fasciolicidal actions of the myrrh-derivative Mirazid in an area of low schistosomiasis transmission. A total of 27 patients infected with Schistosoma mansoni and 16 with Fasciola spp. received the maximum recommended dose of Mirazid. Pretreatment egg counts in 4 Kato-Katz slides were compared with similar counts in stool samples collected 1 and 2 months after treatment. Standard procedures and quality control measures were followed. The results revealed that Mirazid used as schistosomicidal or fasciolicidal agent in the maximum recommended dose has a low cure rate and produced a negligible reduction in egg counts. Prescribing such an ineffective drug in Egypt might endanger the achievements of the schistosomiasis control strategy.

Intra-specimen and day-to-day variations of Fasciola egg counts in human stools

Intra-specimen and day-to-day variations of Fasciola egg counts in stools were investigated for 16 cases of established fascioliasis. For each case six Kato slides from a single stool sample were examined daily for 5 consecutive days. The results indicated the presence of significant intra-specimen variations in more than one-third of the examined series, while the inter-specimen variation was almost negligible. The sensitivity of the Kato-Katz test for diagnosing Fasciola infection with three Kato slides from the same specimen or on different days ranged from 96.0%-99.1%. The examination of three Kato smears from a single stool specimen, which is more feasible in field studies, would give an accurate diagnosis of fascioliasis. Used as such, the Kato-Katz technique is highly sensitive in the diagnosis of fascioliasis.

Identification of the Egyptian species of Fasciola

Reports on the species of Fasciola present in the Nile Delta, Egypt, appear controversial. Some authors reported the presence of both Fasciola gigantica and Fasciola hepatica, others reported F. gigantica only and mentioned that F. hepatica was found only in imported animals. This study was an attempt to identify the species of Fasciola flukes collected from locally bred animals. Morphologic, morphoanatomic, morphometric, and chemotaxonomic criteria of the fluke isolates were studied. Speciation based on morphologic and morphometric data was not decisive due to overlap in the values of most measurements. Morphoanatomic data proved the presence of both the species, and isoelectric focusing (IEF) of fluke soluble protein confirmed the presence of both F. gigantica and F. hepatica in Egypt.

Specific IgG avidity in acute and chronic human fascioliasis

The detection of IgG avidity in sera is potentially useful in the diagnosis of acute and chronic infection. We studied IgG avidity in 31 patients with fascioliasis, with the aim of evaluating the clinical application of this test to confirm the diagnosis of incubating cases and to distinguish between acute and chronic cases. Of the 31 cases, 13 were incubating and had a mean avidity index of 57.28 +/- 5.79%. The 18 chronic cases had an avidity index of 68.80 +/- 8.92%. The difference was highly significant. We conclude that IgG avidity is a reliable means of identifying the stage of fascioliasis and suggest a cut-off point of 59.90% to distinguish between acute and chronic infection.

Circulating antibodies and antigens correlate with egg counts in human fascioliasis

We explored the relationships between specific IgG antibody levels and circulating E/S antigen to intensity of Fasciola infection in the human host. Twenty patients with patent infection and six healthy individuals were enrolled in the study. Intensity of infection was determined by repeated egg counts in stools, while IgG antibodies against adult Fasciola gigantica somatic FI, FII and against E/S antigens were measured as ELISA O.D. readings. The level of circulating E/S antigens was determined by IELISA. Positivity as well as levels of antibodies and antigen correlated with infection intensity. These findings may disclose in the future a relation between morbidity in the acute phase and worm load.

Detection of circulating E/S antigens in the sera of patients with fascioliasis by IELISA: a tool of serodiagnosis and assessment of cure

An IELISA was developed to evaluate the performance of Fasciola E/S antigens in diagnosis and cure assessment of human Fasciola infection. Twenty patients with acute (prepatent) fascioliasis and another 20 with patent infection were enrolled in the study. Patients were treated with TCZ and followed at 1, 3 and 6 months after therapy. At inspection, the sensitivity of the test to diagnose prepatent cases was 100% compared to 70% for patent infections. There was a gradual decrease of antigenaemia over the follow-up period in acute cases. In chronic cases antigen disappeared from 13 cases (65%) at 1 month; this proportion did not change at 3 or 6 months.

Metacercarial precipitin test for diagnosis of human fascioliasis

A metacercarial precipitin test was devised for diagnosis of human fascioliasis. The sera tested were those of cases of fascioliasis (acute and chronic), of schistosomiasis and of normal healthy individuals. Metacercariae were prepared in the laboratory from naturally infected snails. Serum dilutions of 1:5 (20%) and 1:10 (10%) were incubated with metacercariae for periods of 6, 24 and 48 hours. No precipitation was observed when the sera of healthy persons were used. With sera of fascioliasis cases a precipitate was formed which increased in amount with time. It was more rapid in its formation and greater in its quantity with sera of acute fascioliasis. When incubation was prolonged a free precipitate was seen in the medium. With sera of schistosoma cases, a precipitate was observed in a few cases only; it was negligible in amount and localized to the plug area. Metacercarial precipitin is considered a simple, sensitive and specific test for diagnosis of human fascioliasis. It is recommended to use the serum in a dilution of 1:5 (20%), to give preliminary results after 6 hours incubation and to confirm 24 hours later.

Phagocytic activity of neutrophils in human fasciolosis before and after treatment

Neutrophil phagocytic function was studied in fifteen patients with chronic fasciolosis and five in the incubating phase of the disease. Results were compared with a control group. The chematactic index which is the ratio of directed to non directed migration, the (NBT) reduction test which estimates phagocytosis and the more recent and specific test the chemiluminescence which measures phagocytosis and intracellular killing were performed. The results showed that in fasciolosis chemotactic activity, NBT and chemiluminescence index were significantly increased as compared to controls. This increase was more prominent in the acute phase. In this stage, the immature parasites are in close contact with the liver tissue. With chronicity of infection, they reach the bile ducts and inflammation in the liver parenchyma subsides. At this stage a lower level of metabolites and antigens reach the tissues, while the majority pass with bile to the intestinal lumen. The indices returned to normal level after treatment of fasciolosis. This signifies disappearance of all stimuli responsible for activation of PMN phagocytes.

Evaluation of Fasciola excretory-secretory (E/S) product in diagnosis of acute human fasciolosis by IgM ELISA

Diagnosis of fasciolosis in the acute phase depends on a sensitive and accurate serological test. The present study is an evaluation of the efficacy of excretory-secretory Fasciola gigantica adult worm antigen by IgM ELISA. Thirty eight patients with acute fasciolosis and 14 in the chronic phase together with 23 patients with different parasitic infections were introduced in the study. Seventeen healthy, parasite free individuals, were served as controls. A crude excretory-secretory antigen and its fractions I and II (obtained by gel filtration chromatography on Sephadex G-200) were tested. The crude antigen revealed 100% sensitivity, 94% specificity and 98% accuracy at the cut off level of 0.3 in acute infection. It gave positive results in 77% of chronic cases. Cross reactions with Schistosoma and Toxoplasma were negligible. A significant positive correlation between IHA titres and ELISA O.D. readings was observed. Fractions I and II proved of no diagnostic significance. The test system F. gigantica E/S product by IgM ELISA is highly recommended for diagnosis of acute fasciolosis.

Studies on human fascioliasis in Egypt. 1--Seasonality of transmission

The present study aimed at investigating the seasonality of human fascioliasis. The monthly distribution of acute infection was studied together with the monthly Lymnaea cailliaudi snail density and infection Infection was observed in both snail and human host through out the year. However maximal snail infection was observed during the months of June and July while the number of acute human infections peaked in August. It was concluded that summer was the highest transmission season. The clinical incubation period was considered one or two months.

Studies on serum beta-glucuronidase activity and urinary tryptophan metabolites in human fascioliasis

In the last few years, human fascioliasis has been reported more frequently from different parts of the world including Egypt. The present work aimed to study the ability of fascioliasis affected patients to metabolize tryptophan and to explore how this disease can affect the activity of the hydrolytic lysosomal enzyme beta-glucuronidase. Liver and kidney functions and complete blood pictures of the studied patients were considered. Eleven tryptophan metabolites together with 4-pyridoxic acid, the major metabolite of vitamin B6, were determined. Fascioliasis showed an abnormal pattern of tryptophan metabolism which resembled that described earlier by Kupke and Knapp and which indicated that those patients were suffering from vitamin B6 deficiency. This conclusion was proved by the decreased levels of 4-pyridoxic acid. Abnormally high levels of beta-glucuronidase were also encountered in the fascioliasis cases which points to the liver damage caused by the fluke.

Evaluation of Fasciola somatic antigenic fractions in the diagnosis of human fascioliasis

Fasciola somatic antigen was fractionated by column chromatography. Four peaks were obtained. They were evaluated separately using IgG and IgM ELISA in the diagnosis of fascioliasis. Patients were diagnosed through a survey in Abis 13/4 Village depending on stool examination, clinical, haematological findings and on the results of IHAT. Sera were obtained from cases of confirmed fascioliasis, acute fascioliasis, schistosomiasis and from parasite free healthy individuals. After establishing the optimal conditions for the test, ELISA was performed using all fraction and all sera. The results were then computerized and specificity, sensitivity, accuracy, positive predictive value (PPV), negative predictive value (NPV), and probability of disease when test is positive (PDP) were determined at different cut off levels. These parameters were calculated using both sera of normal cases and of S. mansoni infected cases as controls. It was concluded that fraction I in IgG ELISA was the best for diagnosis of chronic cases. Fraction I by IgM was the best for acute infection. Results of the latter antigen/system combination were not decreased when S. mansoni sera were used as control.

A study of the ultrastructure of the intestines of mice experimentally infected with S. mansoni and treated with praziquantel

The present experimental work studied the ultrastructural changes occurring in the intestines of mice infected with S. mansoni and treated with praziquantel. Mild degenerative changes of the intestinal cells together with degranulation of the APUD cells were observed. The enterochromaffin cells in the intestines secrete serotonin which is a vaso constrictor and a strong stimulator of the smooth muscles. A possible explanation of the side effects of praziquantel is thus offered.

Modification of cytochrome P-450, NADPH-cytochrome c reductase and aryl hydrocarbon hydroxylase activities by schistosomicidal drugs

This study was planned to investigate the modification of the mouse microsomal monooxygenase enzymes using various schistosomicidal drugs. Enzymes investigated were cytochrome P-450, NADPH-cytochrome c reductase and aryl hydrocarbon hydroxylase (AHH). Administration of oxamniquine and niridazole increased, whereas praziquantel and hycanthone lowered the cytochrome P-450 content. An apparent increase in the activity of NADPH-cytochrome c reductase was only observed with oxamniquine. The in vivo and in vitro effects of schistosomicidal drugs on the activity of AHH were investigated using benzo(a)pyrene (BP) as substrate. Oxamniquine and niridazole significantly increased the AHH activity in vivo and in vitro, while the antimonial drugs enhanced the enzyme activity only in vivo. On the other hand, praziquantel and hycanthone lowered the AHH activity only in vivo. Metrifonate did not show any effect either in vivo or in vitro. The mechanisms by which these drugs modify the AHH activity are discussed in the text.

Bithionol (Bitin) treatment in established fascioliasis in Egyptians

The present study is an evaluation of bithionol treatment in established fascioliasis. Eight patients were enrolled in the study. All were passing eggs of Fasciola spp. and seven had concomitant Schistosoma mansoni infection. The clinical and haematological findings conformed with the known picture of fascioliasis. Bitin tablets (200 mg) were administered in the dose of 30 mg kg-1 body wt every other day for five doses. Eggs were counted during and for 4 months after the end of therapy. Fasciola ova disappeared after the second or third dose giving a cure rate of 100%. Ova of S. mansoni did not show any change in number. As regards the liver function tests; bilirubin, SGOT and SGPT values were within the normal range and were not affected by treatment. A raised SAP level was observed before therapy which was significantly higher after bithionol. Creatinine phosphokinase and lactate dehydrogenase enzymes and kidney function tests showed almost normal values and were not altered by therapy. It was concluded that Bitin was a potent fasciolicidal drug in the dose used. No side effects were observed.

A short note on praziquantel in human fascioliasis

Ten patients suffering from fascioliasis were treated with praziquantel. In two patients, egg counts dropped to zero following treatment, but there was no significant reduction in egg counts in the other eight.

Intestinal parasitosis in the population of the Yemen Arab Republic

The present work is a report on the various parasitic infections in the Yemeni population during the period 1980-1982. Specimens were received and examined in the Parasitology Department of the Central Public Health Laboratory at Sana'a. Over 37.000 stool specimens and 25.000 urine specimens formed the subject of this study. 53% of the stool specimens were positive for intestinal parasites. T. trichiura, A. lumbricoides and G. lamblia had the highest prevalence. Fasciola ova were found in 0.5% of specimens. N. americanus and A. duodenale were both identified. S. mansoni was detected in 6% of stool specimens and S. haematobium in 2% of urine specimens.

Schistosoma haematobium infection in the white mouse--histopathological and histochemical studies

Mice were infected with 1000 Schistosoma haematobium cercariae (Egyptian strain). Histopathological and histochemical studies were performed on the different organs, during the first four weeks after infection and on the fourth week after oviposition. Pathological changes during early prepatency matched with those in S. mansoni infection. Eggs were laid in aggregates in the colon and liver. They initiated the development of typical granulomatous lesions. Abundant bilharzial pigment and areas of sclerosis were present in both liver and spleen. The heart, kidneys and urinary bladder were pathologically free. Disturbed succinic dehydrogenase and acid phosphatase enzyme levels were detected which point to a derangement in the functions of the cell organelles.

Indirect immunoperoxidase tests in the diagnosis of schistosomiasis

An enzymatic technique, immunoperoxidase histochemistry, was applied in the diagnosis of human schistosomiasis. Sera of patients with S. haematobium, S. mansoni and mixed infection, together with control sera, were studied. The test proved easily applicable and gave reliable results particularly with S. mansoni and double infection. The depth of the colour reaction, was then compared with ELISA readings, but there was no relation in the results of the individual cases.

A focus of human fascioliasis in the Nile Delta, Egypt

This study was carried out in Abis II village. A representative sample of the population was examined for parasitic infections. Of these 40 cases were positive for Fasciola ova and the diagnosis was confirmed. The prevalence of fascioliasis was 7.3 per cent. The egg size was determined in both human and animal samples. Although the ova measurements corresponded in many instances to Fasciola hepatica, yet the identification of the Fasciola spp. needs further investigations.

Granuloma size in the liver of mice with Schistosoma haematobium infection and Schistosoma mansoni challenge

Swiss albino mice have been infected with S. haematobium and challenged with S. mansoni. S. haematobium infection in the mouse runs a course more or less parallel to that of S. mansoni infection. Granuloma has reached a maximal size at 135 days post infection and has regressed thereafter. Suppression of S. mansoni granuloma was observed in mice previously infected with S. haematobium. This manifests the presence of cross immunization.

Diagnosis of bilharziasis (S. haematobium and S. mansoni) by the ELISA using the homologous antigen

Sera of subjects with S. haematobium, S. mansoni and mixed infection were studied by the ELISA by means of homologous antigens. The extinction values for S. haematobium and S. mansoni cases were higher with the homologous antigen. Generally, S. haematobium cases were less reactive than S. mansoni or mixed infection.

The enzyme linked immunosorbent assay in the diagnosis

This study included 72 persons with ova of S. mansoni and/or S. haematobium in their stool or urine, 16 persons from Schistosomiasis-endemic areas but without demonstration of ova, and 9 healthy persons from areas with no schistosomiasis who served as controls. The sera were examined with ELISA using antigen from adult S. mansoni worms. All parasitologically proven cases had extinction values higher than those of controls. False positive results were obtained in 11 out of 16 persons from endemic areas but without ova. These results may have been due to cross-reactions, a past history of schistosomiasis or a missed diagnosis of S. mansoni-infections. Cases with S. haematobium and cases with S. mansoni showed signifcantly different extinction values. The differences between both sexes were not statistically significant.

Studies on experimental mixed infection of Schistosoma haematobium and Schistosoma mansoni in the albino mouse

Swiss albino mice have been infected with S. haematobium and challenged with S. mansoni. No apparent disturbances as regards worm load and oviposition were observed. Yet certain deviations in the egg-distribution sites for both species were found. They were attributed to the possibility of earlier de-development of collateral circulation. Cross-pairing between the two species was met with, which might explain the extra number of S. haematobium eggs found in the small intestine. Although no major effect has been revealed, no conclusion at this stage could be put forward as regards complete absence of cross-immunity.