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

Focusing nucleic acid-based molecular diagnostics and xenomonitoring approaches for human helminthiases amenable to preventive chemotherapy

The current mainstay for control of the four major helminth diseases in humans (lymphatic filariasis, onchocerciasis, soil-transmitted helminthiases and schistosomiasis) is with preventive chemotherapy by mass administration of key anthelminthics. Following the London Declaration on Neglected Tropical Diseases in 2012, a roadmap for the elimination and control of these helminthiases by 2020 has been devised. With expected declines in prevalence and intensity of these infections, there is urgent need for implementing more sensitive, high-throughput and cost-effective diagnostic tools. Currently available diagnostic approaches for surveying, monitoring and evaluating helminth control programmes are based on microscopical observation of eggs/larvae, and/or detection of antibodies or parasite antigens in stool, urine or blood; all relatively low-throughput and of limited sensitivity and specificity. Newly proposed approaches for helminthiases diagnosis include the nucleic acid-based methods of (multiplex) real-time polymerase chain reaction assays, loop-mediated isothermal amplification and recombinase polymerase amplification. However, as well as sensitivity/specificity evaluation, their comparison to current ‘gold standard’ diagnostics and future application in individual-/community-based diagnosis, or in xenomonitoring requires consideration of relative costs, agreement of standard methods and strategic interpretation of resulting data before control/elimination programmes might best utilize molecular diagnostics to inform decision making. We review current nucleic-acid-based molecular diagnostic methods and highlight the needs and future research required to refine these tools for monitoring and evaluation of control and elimination programmes for four major human helminthiases

A systematic review with epidemiological update of male genital schistosomiasis (MGS): A call for integrated case management across the health system in sub-Saharan Africa.

Male genital schistosomiasis (MGS) is a gender specific manifestation of urogenital schistosomiasis (UGS) first described in 1911 by Madden in Egypt. Today, while affecting millions of men and boys worldwide, MGS receives insufficient attention, especially in sub-Saharan Africa (SSA). To provide a systematic review with an epidemiological update of MGS, we inspected both online and hardcopy resources in our appraisal. A total of 147 articles were eventually identified, only 31 articles were exclusively focused on MGS with original or targeted research. From these, we discuss pertinent clinico-pathological features of MGS, highlight the possible connection and interplay with HIV, and assess current diagnostic techniques alongside consideration of their use and application in SSA. To appreciate the burden of MGS more fully, especially in endemic areas, there is a clear need for better surveillance and longitudinal population research to investigate the best point-of-care (POC) diagnostic and its performance through time. Furthermore, to optimise individual case management, exploration of alternative praziquantel dosing regimens is needed for MGS in men with or without HIV co-infection

An update on non-invasive urine diagnostics for human-infecting parasitic helminths: what more could be done and how?

Reliable diagnosis of human helminth infection(s) is essential for ongoing disease surveillance and disease elimination. Current WHO-recommended diagnostic assays are unreliable in low-endemic near-elimination settings and typically involve the invasive, onerous and potentially hazardous sampling of bodily fluids such as stool and blood, as well as tissue via biopsy. In contrast, diagnosis by use of non-invasive urine sampling is generally painless, more convenient and low risk. It negates the need for specialist staff, can usually be obtained immediately upon request and is better accepted by patients. In some instances, urine-based diagnostic assays have also been shown to provide a more reliable diagnosis of infection when compared to traditional methods that require alternative and more invasive bodily samples, particularly in low-endemicity settings. Given these relative benefits, we identify and review current research literature to evaluate whether non-invasive urine sampling is currently exploited to its full potential in the development of diagnostic tools for human helminthiases. Though further development, assessment and validation is needed before their routine use in control programmes, low-cost, rapid and reliable assays capable of detecting transrenal helminth-derived antigens and cell-free DNA show excellent promise for future use at the point-of-care in high-, medium- and even low-endemicity elimination settings

Moving from control to elimination of schistosomiasis in sub-Saharan Africa: time to change and adapt strategies.

Schistosomiasis is a water borne parasitic disease of global importance and with ongoing control the disease endemic landscape is changing. In sub-Saharan Africa, for example, the landscape is becoming ever more heterogeneous as there are several species of Schistosoma that respond in different ways to ongoing preventive chemotherapy and the inter-sectoral interventions currently applied. The major focus of preventive chemotherapy is delivery of praziquantel by mass drug administration to those shown to be, or presumed to be, at-risk of infection and disease. In some countries, regional progress may be uneven but in certain locations there are very real prospects to transition from control into interruption of transmission, and ultimately elimination. To manage this transition requires reconsideration of some of the currently deployed diagnostic tools used in surveillance and downward realignment of existing prevalence thresholds to trigger mass treatment. A key challenge will be maintaining and if possible, expanding the current donation of praziquantel to currently overlooked groups, then judging when appropriate to move from mass drug administration to selective treatment. In so doing, this will ensure the health system is adapted, primed and shown to be cost-effective to respond to these changing disease dynamics as we move forward to 2020 targets and beyond

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

Future schistosome hybridizations: Will all Schistosoma haematobium hybrids please stand-up!

nterrogating the genetic make-up of schistosome larvae (i.e. eggs, miracidia and cercariae) originating from definitive or intermediate snail hosts with molecular DNA methods has, by noting unexpected inter-species hybrids, started a revolution in our appraisal of African schistosomiasis [1-4]. Here, two dominant species of human schistosome exist, Schistosoma haematobium and S. mansoni, which are transmitted by specific intermediate freshwater snails, Bulinus spp. for the former and Biomphalaria spp. for the latter. The two schistosomes cause either urogenital or intestinal schistosomiasis, respectively [5] and depending on local snail distributions, schistosome transmission zones in the aquatic habitat may or may not overlap [6]. Within the S. haematobium group, a further 8 sister species are described with S. intercalatum and S. guineensis of medical importance, causing intestinal schistosomiasis while others, such as S. bovis, S. curassoni and S. mattheei occur in livestock, with the remaining species infecting wildlife. Schistosoma mattheei is also of medical interest for occasional infection and associated disease [7]. In contrast, S. mansoni has a single sister species, S. rodhaini, typically found in small rodents which can hybridise with S. mansoni, if given sufficient opportunity [2]