Preventive chemotherapy for schistosomiasis and soil-transmitted helminthiasis by cotreatment with praziquantel and albendazole

In disease-endemic areas, preventive chemotherapy with two orally administered anthelminthic drugs, praziquantel and albendazole, forms the foundation of control of schistosomiasis and soil-transmitted helminthiasis. Where diseases overlap, these two drugs are typically co-administered simultaneously, although albendazole is often interchangeable with mebendazole. With a supportive pharmaceutical industry that donates drugs and a strong international partnership that mobilizes donor funds for drug delivery, scale-up of treatment in school-aged children has expanded significantly in line with the WHO 2012–2020 strategic plan. Other high-risk groups, such as pre-school-aged children, are now benefiting from deworming campaigns conducted alongside other childhood interventions,such as vaccination, less so, however, for schistosomiasis as infections in this age class are not being treated. Looking to the future, maintaining an effective drug distribution and reporting system that regularly checks anthelminthic performance alongside documenting improvements in child health are essential for the long-term success of preventive chemotherapy with praziquantel and albendazole

Celebrating 150 volumes of Parasitology with an outlook towards 2030 production

Avid readers of our journal will have noticed that the end of 2023 saw the completion of the 150th volume of Parasitology. This is a landmark statistic in long-term scientific publishing which defines an impressive academic legacy that goes on to support the future study of parasites around the world. Over this past year and perhaps more discernible, submitting authors will have realised that Parasitology is now an Open Access (OA) journal. Since January 2023, Parasitology is following a Gold Open Access Model, specifically a nonexclusive Gold Open Access CC-BY licence (see https://www.cambridge.org/core/services/open-access-policies/open-accessresources/creative-commons-licenses

Molecular characterization of freshwater snails in the genus Bulinus: a role for barcodes?

<p>Abstract</p> <p>Background</p> <p>Reliable and consistent methods are required for the identification and classification of freshwater snails belonging to the genus <it>Bulinus </it>(Gastropoda, Planorbidae) which act as intermediate hosts for schistosomes of both medical and veterinary importance. The current project worked towards two main objectives, the development of a cost effective, simple screening method for the routine identification of <it>Bulinus </it>isolates and the use of resultant sequencing data to produce a model of relationships within the group.</p> <p>Results</p> <p>Phylogenetic analysis of the DNA sequence for a large section (1009 bp) of the mitochondrial gene cytochrome oxidase subunit 1 (<it>cox1</it>) for isolates of <it>Bulinus </it>demonstrated superior resolution over that employing the second internal transcribed spacer <it>(its2</it>) of the ribosomal gene complex. Removal of transitional substitutions within <it>cox1 </it>because of saturation effects still allowed identification of snails at species group level. Within groups, some species could be identified with ease but there were regions where the high degree of molecular diversity meant that clear identification of species was problematic, this was particularly so within the <it>B. africanus </it>group.</p> <p>Conclusion</p> <p>The sequence diversity within <it>cox1 </it>is such that a barcoding approach may offer the best method for characterization of populations and species within the genus from different geographical locations. The study has confirmed the definition of some accepted species within the species groups but additionally has revealed some unrecognized isolates which underlines the need to use molecular markers in addition to more traditional methods of identification. A barcoding approach based on part of the <it>cox1 </it>gene as defined by the Folmer primers is proposed.</p

Confirmed local endemicity and putative high transmission of Schistosoma mansoni in the Sesse Islands, Lake Victoria, Uganda

The Sesse Islands, in the Ugandan portion of Lake Victoria, have long been considered a low transmission zone for intestinal schistosomiasis. Based on observations of high prevalence of Schistosoma mansoni infection in the northern-most islands of this archipelago, a follow-up survey was conducted to ascertain whether transmission was endemic to this island group, combining parasitological and malacological surveys. Prevalence of intestinal schistosomiasis was again observed to be high, as was intensity of infections which, combined with low reported incidence of treatment, suggests that chemotherapy-based control initiatives are not being maximally effective in this region as high levels of population movement between islands and districts are confounding. The local disease transmission was confirmed by the observations of high abundance of Biomphalaria, as well as field-caught snails shedding S. mansoni cercariae. DNA sequencing of 12 cercariae revealed common mitochondrial cox1 haplotypes, as well as, novel ones, consistent with the high genetic diversity of this parasite in Lake Victoria. Intestinal schistosomiasis is firmly endemic in parts of the Sesse Islands and more broadly, this island group provides an insight into the future challenges to be faced by the Ugandan National Control Programme in regularly reaching these rather remote, inaccessible and largely itinerant communities

A Fresh Insight into Transmission of Schistosomiasis: A Misleading Tale of Biomphalaria in Lake Victoria

Lake Victoria is a known hot-spot for Schistosoma mansoni, which utilises freshwater snails of the genus Biomphalaria as intermediate hosts. Different species of Biomphalaria are associated with varying parasite compatibility, affecting local transmission. It is thought that two species, B. choanomphala and B. sudanica, inhabit Lake Victoria; despite their biomedical importance, the taxonomy of these species has not been thoroughly examined. This study combined analysis of morphological and molecular variables; the results demonstrated that molecular groupings were not consistent with morphological divisions. Habitat significantly predicted morphotype, suggesting that the different Lake Victorian forms of Biomphalaria are ecophentoypes of one species. The nomenclature should be revised accordingly; the names B. choanomphala choanomphala and B. c. sudanica are proposed. From a public health perspective, these findings can be utilised by policy-makers for better understanding of exposure risk, resulting in more effective and efficient control initiatives

Female genital schistosomiasis (FGS): from case reports to a call for concerted action against this neglected gynaecological disease

AbstractIn recent years, control of neglected tropical diseases has been increasingly gaining momentum and interventions against schistosomiasis are being progressively scaled-up through expansion of donated praziquantel and preventive chemotherapy campaigns. However, the public health importance of female genital schistosomiasis is not fully recognised nor its control is adequately addressed. Taking a clinical and anatomopathological perspective, we evaluated the available literature to highlight the importance of female genital schistosomiasis and its connections with two sexually transmitted infections of global importance, Human Immunodeficiency Virus (HIV) and Human Papilloma Virus. Outside the long list of clinical descriptive reports beginning in 1899, there is presently a shocking gap in epidemiological assessment and a significant underestimation of the burden of FGS remains. The scarcity of integrated approaches to address female genital schistosomiasis calls for more concerted action in its detection, treatment and prevention alongside other concomitant women’s health issues, otherwise female genital schistosomiasis will remain a neglected gynaecological disease

Associations between trematode infections in cattle and freshwater snails in highland and lowland areas of Iringa Rural District, Tanzania

SUMMARYThe epidemiology of trematode infections in cattle was investigated within highland and lowland areas of Iringa Rural District, in southern Tanzania. Fecal samples were collected from 450 cattle in 15 villages at altitudes ranging from 696 to 1800 m above the sea level. Freshwater snails were collected from selected water bodies and screened for emergence of cercariae. The infection rates in cattle wereFasciola gigantica28·2%, paramphistomes 62·8% andSchistosoma bovis4·8%. Notably, prevalence of trematode infections in cattle was much higher in highland (altitude &gt; 1500 m) as compared with lowland (altitude &lt; 1500 m) areas and was statistically significant (P-value = 0·000) forF. giganticaand paramphistomes but not forS. bovis. The snails collected includedLymnaea natalensis, Bulinus africanus, Bulinus tropicus, Bulinus forskali, Biomphalaria pfeifferi, Melanoides tuberculataandBellamya constrictawith a greater proportion of highland (75%) than lowland (36%) water bodies harbouring snails. Altitude is a major factor shaping the epidemiology ofF. giganticaand paramphistomes infections in cattle in Iringa Rural District with greater emphasis upon control needed in highland areas.</jats:p