[Dynamics of Egg Excretion of Schistosoma haematobium in a Longitudinal Cohort Under Treatment with Praziquantel over a Five-Year Period in Kalifabougou, Mali]. / Dynamique de l'excrétion ovulaire de Schistosoma haematobium dans une cohorte de Kalifabougou (Mali) sous traitement par le praziquantel (PZQ) durant cinq ans.

This study aim was to evaluate the dynamics of Schistosoma haematobium eggs excretion after the scaling up of "Mass Drug Administration" (MDA) with praziquantel (PZQ) from 2011 to 2016 in a cohort of volunteers living in the village of Kalifabougou, Mali. We conducted a cross-sectional study on 676 volunteers in May 2011 niched in cohort study from 696 volunteers aged three months to 25 years. The eggs of Schistosoma haematobium (Sh) were tested by urine filtration technique, Soil-transmitted helminth and Schistosoma mansoni by the Kato-Katz technique. Maximal MDA/ PZQ population coverage was 83% in 2015 and no MDA/PZQ n 2014. A total of 676 volunteers was included in this prospective cohort. The prevalence rate of Sh showed a significate decreasing from 2011, 2013 to 2014 with respectively 10.2% [95% CI=10.04-10,18], 5.32% [95% CI=5.30-5.33], and 5.25% [95% CI=524.-5.31], followed by an increase to 10.6% [95% CI = 10.47-10.63] in 2015 and a significative decrease in 2016 to 5.4% [95% CI=3.5-7,3]. Children aged from six to 10 years and mostly boys were more infected with Sh, then could serve of parasite reservoir. MDA with PZQ remains an effective strategy for schistosomiasis control against Sh in Kalifabougou. Additional studies on MDA/PZQ average treatment covering human-water contact behaviors and population migration are necessary to understand the persistence of the 5% annual prevalence rate of egg shedding in the cohort of volunteers periodically treated with PQZ. Testing eggs shed viability will be also an added value.

L'objectif de cette étude était d'évaluer la dynamique de l'excrétion ovulaire de Schistosoma haematobium (Sh) après la mise à échelle du « traitement de masse ¼ (TDM) avec le praziquantel (PZQ) de 2011 à 2016 dans une cohorte de volontaires vivant dans le village de Kalifabougou au Mali. Nous avons conduit une étude transversale sur 676 volontaires au mois de mai 2011 nichée dans une étude de cohorte de 695 volontaires, âgés de 3 mois à 25 ans et suivis de 2011 à 2016. Les œufs de Sh ont été recherchés par la technique de filtration d'urines et ceux des géo helminthes et de Schistosoma mansoni avec le Kato-Katz. Le taux de couverture maximum de la population cible de Kalifabougou en TDM/PZQ était de 83 % en 2015 et il n'a pas eu de TDM/PZQ en 2014. Le taux de prévalence de Sh montrait une réduction significative entre 2011, 2013 et 2014 avec respectivement 10,20 % [95 % CI = 10,04-10,18]- 5,32 % [95 % CI = 5,30- 5,33], et 5,25 % [95 % CI = 5,24-5,31], suivi d'une augmentation à 10,60 % [95 % CI = 10,47-10,63] en 2015 et d'une baisse significative en 2016 à 5,40 % [95 % CI = 3,5-7,3]. Les enfants âgés de six à dix ans, et majoritairement les garçons, seraient plus infectés par Sh, et pourraient servir de réservoir de parasites. Le TDM avec le PZQ reste une stratégie efficace pour le contrôle de la schistosomose à Sh à Kalifabougou. Des études complémentaires sur la couverture moyenne en TDM-PZQ, les comportements de contact homme-eau et les mouvements de population sont nécessaires pour comprendre la persistance du taux de prévalence annuel de 5 % de l'excrétion ovulaire dans la cohorte de volontaires traités périodiquement par le PQZ. Un test de viabilité des œufs excrétés serait aussi une valeur ajoutée.

Detecting hybridization in African schistosome species: does egg morphology complement molecular species identification?

Hybrid parasites may have an increased transmission potential and higher virulence compared to their parental species. Consequently, hybrid detection is critical for disease control. Previous crossing experiments showed that hybrid schistosome eggs have distinct morphotypes. We therefore compared the performance of egg morphology with molecular markers with regard to detecting hybridization in schistosomes. We studied the morphology of 303 terminal-spined eggs, originating from 19 individuals inhabiting a hybrid zone with natural crosses between the human parasite Schistosoma haematobium and the livestock parasite Schistosoma bovis in Senegal. The egg sizes showed a high variability and ranged between 92·4 and 176·4 µm in length and between 35·7 and 93·0 µm in width. No distinct morphotypes were found and all eggs resembled, to varying extent, the typical S. haematobium egg type. However, molecular analyses on the same eggs clearly showed the presence of two distinct partial mitochondrial cox1 profiles, namely S. bovis and S. haematobium, and only a single nuclear ITS rDNA profile (S. haematobium). Therefore, in these particular crosses, egg morphology appears not a good indicator of hybrid ancestry. We conclude by discussing strengths and limitations of molecular methods to detect hybrids in the context of high-throughput screening of field samples.

Ultra-low-cost urine filtration for Schistosoma haematobium diagnosis: a proof-of-concept study.

Simple, efficient, and cost-effective strategies are needed for urine sample preparation in the field diagnosis of infection with Schistosoma haematobium. In this proof-of-concept study, we evaluated inexpensive and widely available paper products (paper towels, school workbook paper, and newspaper) to gravity-filter urine containing 60 eggs/mL of Schistosoma haematobium. Eggs were reliably visualized by light microscopy by using single-ply paper towels as urine filters. This filtration method has broad applicability in clinical and public health settings in resource-constrained environments.

The emerging threat of schistosomiasis spread in Pakistan.

Schistosomiasis is among the thirteen neglected tropical diseases of the world. While prevalent in a number of countries, it has only rarely been reported in Pakistan. Here we report a 25 year old male who acquired the infection during travel to Malawi and presented with haematuria and dysuria. He was successfully treated with praziquantel. The possibility of schistosomiasis becoming endemic in the country is discussed. A number of risk factors are present including dams, irrigation, increased travel and geographical proximity to endemic countries. The local presence of at least one snail species of potential hosts for Schistosoma mansoni is confirmed. We see that schistosomiasis endemicity is a possible threat in Pakistan. Solutions to prevent this include reducing travel to endemic areas, prompt recognition and treatment of cases, and health education.

Applications for profiling the schistosome transcriptome.

Some of the most fruitful applications of gene expression studies of schistosome parasites have occurred in the last decade. Recent transcriptomics approaches to schistosome research from an expanding biological perspective will be reviewed, ranging from the whole organism tissue or cellular levels. The latest studies of transcription in relation to schistosome-host interactions are examined, including the impact of the environment or therapies on the parasite and the reciprocal impact the parasite has on the host. Finally, the relevance of transcriptomics for exploring and contrasting different parasite populations or species is discussed.

Diagnosis of Schistosoma haematobium on voided urine cytology: a case report with radiologic correlation.

BACKGROUND: Infection with schistosomal species is becoming a more frequent finding in hospitals throughout the United States. Some causes that can be attributed to the rise include increased immigration from and travel to endemic areas. CASE: We report a case of urinary schistosomiasis diagnosed on urine cytology in a 7-year-old Nigerian boy. Infection was suspected after review of the clinical history and correlation with radiologic images. CONCLUSION: The rise in incidence has made it necessary for cytopathologists to be increasingly aware of these infections, in particular, Schistosoma haematobium, because it is the most frequent agent to be encountered on a cytology specimen, particularly urine. Similar cases have been published, one with specimen concentration and one without. However, no cases of cytology diagnosis with radiologic correlation are seen in the English literature.

Diagnostic value of a miracidium in urinary sediment.

Although rarely encountered in the United States, urinary tract schistosomiasis occurs commonly in many countries in the eastern hemisphere. Travel and immigration may contribute to imported cases of schistosomiasis. Excessive morbidity and increased mortality, including the development of urinary-tract squamous-cell carcinoma, are associated with untreated Schistosoma haematobium infection. Therefore, in the appropriate clinical context, all efforts should be made to rule out infectious and readily treatable causes of chronic hematuria. The presence of characteristic eggs in the urinary sediment is the usual means of diagnosing a S. haematobium infection. Additionally, the small and less commonly encountered miracidium stage of S. haematobium may also be present in the urine, which is another means of diagnosing urinary tract schistosomiasis. The present report describes a case in which a miracidium was detected in a fresh, unstained urine specimen. As detection of miracidia can be made in specimens also processed by routine cytologic methods, it behooves cytologists to be aware of this entity for the diagnosis of schistosomiasis.

[Paleoparasitology: presumption of a case with bilharzia of the 15th century at Montbéliard (Doubs, France)]. / Paléoparasitologie: présomption d'un cas de bilharziose au XVe siècle à Montbéliard (Doubs, France).

On the archeological site of Montbéliard, paleoparasitological and sedimentological analysis of cesspit deposits led to the detection of well preserved parasitological forms (remains of helminths with associated eggs). The morphology and morphometry of these forms point to a plausible case of bilharzia transmitted by Schistosoma haematobium. The chance of ancient or recent contamination of the sample is discussed.

Speed of skin penetration and initial migration route of infective larvae of Schistosoma haematobium in Meriones unguiculatus.

The kinetics of skin penetration of Schistosoma haematobium (Bilharz, 1852) (Trematoda, Schistosomatidae) cercariae is reported for the first time, Meriones unguiculatus (Rodent, Gerbillidae) being used as experimental model. It has been demonstrated that the cercariae cross the epidermis of their hosts either directly or through hair follicles culs-de-sac from 3 to 5 min. The corresponding schistosomulae slide into the superficial part of the dermis or move along the base of hair follicles. Six minutes after, schistosomulae are found in the lumen of lymphatic vessels running alongside blood capillaries. One hour post-infestation, the dermis presents acute inflammatory reaction with edema, infiltration of neutrophil and eosinophil leukocytes. Conversely, dilated blood capillaries do not contain any schistosomula. Thus, the initial migration path of infective larvae of S. haematobium in M. unguiculatus is lymphatic.

A study of the biological characteristics of a hybrid line between male Schistosoma haematobium (Dar es Salaam, Tanzania) and female S. intercalatum (Edea, Cameroun).

The viability of a hybrid between male Schistosoma haematobium (Dar es Salaam, Tanzania) and female S. intercalatum (Edea, Cameroun) was studied for up to the F7 hybrid generation and the biological characteristics of the hybrid were compared with those of each of the parental species. Using the total cercarial production/100 exposed snails/5 weeks value (TCP) as an index the hybrid miracidial infectivity to Bulinus forskalii (Kinshasa, Zaire), the host snail for S. intercalatum, remained comparable to that of S. intercalatum for up to at least the F5 generation and the TCP values for the hybrid/B. wrighti combination remained for up to the F7 generation intermediate between those of the parental species in B. wrighti. The hybrid also retained the infectivity for up to at least the F5 generation to B. globosus (Mazeras, Kenya), the host snail for S. haematobium, but the TCP values for the hybrid/B. globosus combination remained consistently lower than that of the S. haematobium/B. globosus combination. The hybrid cercarial infectivity to hamsters was for up to the F7 generation comparable to that of both parental species and the egg production capacity/worm pair/day of production of the F1 hybrid generation exceeded in both hamsters and mice that of both parental species. However, the egg production capacity subsequently decreased with that of the F3 to F6 generations in hamsters and with that of the F2 and F5 generations in mice being comparable to that of S. intercalatum. The pattern of distribution of eggs in tissue of hamsters of the F1 and F2 generations resembled that of S. haematobium and S. intercalatum, respectively, but the distributional pattern of the F3 to F6 generations deviated markedly from that of both the parental species and the preceding hybrid generations. The hybrid cercarial infectivity to mice and the pattern of egg distribution corresponded to that of S. intercalatum. The egg morphology of the P1 generation corresponded to that of S. intercalatum while that of the F1, F2 and F3 hybrid generations exhibited great polymorphism with a range of shapes through those of the parental species but with most eggs being intermediate in shape. However, the eggs of the F4 to F7 hybrid generations exhibited less polymorphism and resembled those of S. bovis in both size and shape.

A comparative study of the vitelline cell in Schistosoma mansoni, S. haematobium, S. japonicum and S. mattheei.

A comparison is given of the ultrastructure of the vitelline cell in Schistosoma mansoni, S. haematobium, S. japonicum and S. mattheei. Four stages in development of the vitelline cell have been categorized as follows: Stage 1, the undifferentiated cell; Stage 2, the developing cell showing the beginning of synthetic activity; Stage 3, the developing cell showing active protein synthesis; Stage 4, the fully mature vitelline cell. These stages in development have been defined morphologically and Stages 1, 2 and 3 are very similar in all 4 species. Lipid is present in the Stage 4 cells of all species but appears earlier at Stage 3 in S. haematobium and S. mattheei. There are several differences as to the intercellular inclusions of the Stage 4 cells, the most marked of these being the absence of calcareous corpuscles from S. japonicum as compared with the other 3 species.

Multispecies schistosomal infections of the female genital tract detected in cytology smears.

Egg morphology of Schistosomes affecting man in Africa is described and illustrated with particular reference to the appearance of the ova of S. haematobium, S. mansoni and S. mattheei in Papanicolaou stained smears.

The timing of reproductive cell development and movement in Schistosoma mansoni, S. japonicum, and S. haematobium, using techniques of autoradiography and transplantation.

Tritiated thymidine was incorporated into gonial and vitelline cells of male and female Schistosoma mansoni, S. japonicum, and S. haematobium after 2 hr of incubation. Spermatogonial cells developed into labeled mature sperm after 6 days of transplantation in all species. Insemination of females was detected on the same day indicating copulation is frequent. Oogonia labeled in the initial incubation matured into primary oocytes after 7 days of transplantation for S. mansoni and S. haematobium and after 6 days in S. japonicum. Cytoplasmic thymidine label was observed after 2-hr incubations in the primary oocytes of all species. Initial label in the vitellaria was scattered and heavy. After 3 days of transplantation, label was considerably diluted and by day 6 was undetectable in vitelline glands. These times for development and movement of reproductive cells are considered to be standards against which the effects of stressful conditions on the reproductive system can be assessed.

Culture of Schistosoma haematobium in vivo and in vitro.

The maximum rate of development of Schistosoma haematobium in the hamster was determined by examination of the most advanced worms recovered at short intervals throughout the course of development. In culture S. haematobium developed at the same rate as in the hamster up to day 31 when pairing first occurs and male worms produce some spermatozoa. In vitro males formed some spermatozoa but pairing did not take place and, probably for this reason, females did not complete sexual maturation as occurs in the host between days 57-65. Somatic growth continued in vitro and at 70 days male worms had achieved almost the same length as in the hamster at this time. The culture medium, previously used for S. mansoni, consisted of equal volumes of serum and Earle's balanced saline with a final concentration of 0.25% lactalbumin hydrolysate, 100 units/ml penicillin, 100 mug/ml streptomycin and 1% rbc. The best culture results were obtained with one particular human serum; seven other human sera gave a wide range of growth support. The samples of baboon, rhesus monkey or foetal calf sera tested provided little or no growth support but prolonged survival was possible in all the sera.