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Background: Schistosomiasis is an important snail-borne parasitic disease whose transmission is exacerbated by water resource management activities. In Rwanda, meeting the growing population's demand for food has led to wetlands reclamation for cultivation and increased agrochemical enrichment for crop production. However, the ecological consequences of agrochemical enrichment on schistosomiasis transmission remain unexplored. Methods: A malacological survey was conducted in 71 villages selected from 15 schistosomiasis endemic districts. Snail sampling was done in wetlands used for agriculture, along lake Kivu and at constructed multipurpose water dams. Water physico-chemical parameters were collected at all snail sampling sites. Analysis of collected data was performed using Xgboost (gain) and Random Forest (mean decrease in accuracy), machine learning techniques, to construct models that evaluate and categorize the importance of all physico-chemical properties on the presence and abundance of intermediate host snails (IHS). Results: Different sets of parameters were relevant for the presence and abundance of Biomphalaria spp. and/or Bulinus spp. snails. Electrical conductivity, elevation, magnesium and lead content were deemed to shape the presence and abundance of Bulinus spp. snails. The impact of phosphate ion concentration, ammonia ions, total nitrogen and total organic carbon levels mirrored their importance towards the presence and abundance of Biomphalaria spp. Factors such as pH, electric conductivity, total nitrogen content and total organic carbon influenced the coexistence of both species. Our study highlights the value of integrating a wide range of predictor variables, enabling effective variable selection to uncover important predictors of snail distribution. Conclusion: The results suggest that agrochemical compounds can enhance the abundance of IHS leading to an increased risk of Schistosoma transmission. Snail surveillance could therefore be integrated into agricultural expansion projects in our match towards schistosomiasis elimination. Recognizing the impact of agrochemicals on IHS is crucial for minimizing schistosomiasis transmission among those working in wetlands while meeting the growing need for food. Author summary: Schistosomiasis is a neglected tropical disease (NTD) affecting more than 250 million people worldwide, the biggest burden being in Africa. In Rwanda, a national control program was established in 2008 and since then, regular mass deworming campaigns target populations at risk. However, quinquennial mapping surveys and epidemiological studies reveal areas with persistent infection and new foci of transmission. Since these foci often coincide with water bodies used for agricultural activities, this study aimed to investigate how agrochemical compounds and physical properties of water bodies influence the distribution and abundance of snails that are intermediate hosts for Schistosoma parasites. We used in comparison two machine learning approaches to analyze a wide range of physico-chemical parameters of water bodies in relation to snail abundance throughout the country. Findings indicate that water acidity and chemicals like those found in fertilizers influence the abundance of snails, confirming that agricultural expansion may carry the unwanted burden of schistosomiasis transmission. As the country aims to move towards schistosomiasis elimination as a public health problem, it is imperative to integrate infection control such as public health education, snail control (improved agricultural practices), and mass drug administration into efforts to improve agricultural production. [ABSTRACT FROM AUTHOR]

Abstract: Background: Intestinal schistosomiasis remains a worrying health problem, particularly in western Côte d'Ivoire, despite control efforts. It is therefore necessary to understand all the factors involved in the development of the disease, including biotic and abiotic factors. The aim of this study was to examine the factors that could support the maintenance of the intermediate host and its vectorial capacity in western Côte d'Ivoire. Methods: Data on river physicochemical, microbiological, and climatic parameters, the presence or absence of snails with Schistosoma mansoni, and human infections were collected between January 2020 and February 2021. Spearman rank correlation tests, Mann–Whitney, analysis of variance (ANOVA), and an appropriate model selection procedure were used to analyze the data. Results: The overall prevalence of infected snails was 56.05%, with infection reaching 100% in some collection sites and localities. Of 26 sites examined, 25 contained thermophilic coliforms and 22 contained Escherichia coli. Biomphalaria pfeifferi was observed in environments with lower land surface temperature (LST) and higher relative air humidity (RAH), and B. pfeifferi infection predominated in more acidic environments. Thermal coliforms and E. coli preferred higher pH levels. Lower maximum LST (LST_Max) and higher RAH and minimum LST (LST_Min) were favorable to E. coli, and lower LST_Max favored coliforms. The presence of B. pfeifferi was positively influenced by water temperature (T °C), LST_Min, RAH, and precipitation (Pp) (P < 0.05) and negatively influenced by pH, total dissolved solids (TDS), electrical conductivity (EC), LST_Max, and mean land surface temperature (LST). The parameters pH, TDS, EC, LST_Min, LST, and Pp had a positive impact on snail infection, while LST_Max had a negative impact on infection. Only pH had a positive effect on coliform and E. coli abundance. Of the 701 people examined for human schistosomiasis, 73.13% were positive for the point-of-care circulating cathodic antigen (POC-CCA) test and 12.01% for the Kato–Katz (KK) test. A positive correlation was established between human infections and the abundance of Biomphalaria (r2 = 0.879, P = 0.04959). Conclusions: The results obtained reflect the environmental conditions that are conducive to the maintenance of S. mansoni infection in this part of the country. To combat this infection as effectively as possible, it will be necessary not only to redouble efforts but also to prioritize control according to the level of endemicity at the village level. [ABSTRACT FROM AUTHOR]

Background: Schistosomiasis is a neglected tropical disease caused by trematodes of the genus Schistosoma. The pathogen is transmitted via freshwater snails. These snails are highly tolerant to agricultural pesticides and indirectly benefit from exposure due to adverse effects on their more sensitive enemy species. Pesticides in surface waters may thus increase the risk of schistosomiasis transmission unless they also affect the pathogen. We tested the tolerance of the free-swimming life stages (miracidia and cercariae) of Schistosoma mansoni to the insecticides diazinon and imidacloprid. We also investigated whether these pesticides decrease the ability of miracidia to infect and further develop as sporocysts within the host snail Biomphalaria pfeifferi. Results: Exposure to imidacloprid for 6 and 12 h immobilized 50% of miracidia at 150 and 16 µg/L, respectively (nominal EC50); 50% of cercariae were immobilized at 403 and 284 µg/L. Diazinon immobilized 50% of miracidia at 51 and 21 µg/L after 6 and 12 h; 50% of cercariae were immobilized at 25 and 13 µg/L. The observed insecticide tolerance is lower than those of the host snail B. pfeifferi and comparable to those of other commonly tested freshwater invertebrates. Exposure for up to 6 h decreased the infectivity of miracidia at high sublethal concentrations (48.8 µg imidacloprid/L and 10.5 µg diazinon/L, i.e. 20–33% of EC50), but not at lower concentrations commonly observed in the field (4.88 µg imidacloprid/L and 1.05 µg diazinon/L). The development of sporocysts within the snail host was not affected at any of these test concentrations. Conclusions: Insecticides did not affect the performance of S. mansoni at environmentally relevant concentrations. Particularly within its host snail the pathogen can escape exposure peaks that have been shown to affect other sensitive invertebrates and their biological control of host snails. Our findings suggest that freshwater pollution with agricultural pesticides increases the risk of schistosomiasis; they illustrate the need to integrate an environmental and public health risk assessment and management. [ABSTRACT FROM AUTHOR]

Background: Multi-factorial reasons are an induction to cause cancer. Different infections and infestations with viruses, bacteria, and parasites have been detected for many years to be related to human carcinogenesis. Purpose: The study aimed to review all ideas of tumor carcinogenesis and its associations with parasitic infections and infestations. Methods: We reviewed several articles (published and imprinted) by selecting, extracting, and synthesizing data about the relationship between cancers and parasites. Results: Several helminths infections as schistosomiasis, are highly carcinogenic agents for bladder cancer, whereas trypanosomiasis has a bi-model role in cancer development. Leishmaniasis may be a cause of hepatocarcinoma, skin cancer, and lymphomas. In addition, malaria appears to be causative in the carcinogenesis of some cancers; as Burkitt lymphoma. Also, data from previous studies suggested that Strongyloides stercoralis may be a relevant co-factor in lymphomas. Conclusion: There are different mechanisms of parasitic infection to be enhancing in carcinogenesis of cancer in human. [ABSTRACT FROM AUTHOR]

Background: Patients' adherence to artemisinin-based combination therapy (ACT) is a malaria control strategy. Studies report varied experiences regarding patients' adherence to ACT. The study aimed at determining factors influencing patients' adherence to ACT for malaria in Kamuli, Uganda. Methods: In a longitudinal study, 1266 participants at 8 public health facilities were enrolled. Equal numbers (422) were assigned to the three arms (no follow-up, day 2 and day 4). To establish the mean difference between groups, Student t-test was used and a chi-square test was used for proportionality. A multivariate logistic regression analysis was used to establish the influence of predictor variables on the dependent variable. Statistical significance was established at p < 0.05. Results: A total of 844 patients were analysed. The median age was 20 years, majority (64.3%) were females. Overall patients' adherence was 588/844 (69.7%). At bivariate level, age (t-test = 2.258, p = 0.024), household head (χ2 = 14.484, p = 0.002), employment status (χ2 = 35.886, p < 0.0001), patients' preference of ACT to other anti-malarials (χ2 = 15.981, p < 0.0001), giving a patient/caregiver instructions on how to take the medication (χ2 = 7.134, p = 0.011), being satisfied with getting ACT at facility (χ2 = 48.261, p < 0.0001), patient/caregiver knowing the drug prescribed (χ2 = 5.483, p = 0.019), patient history of saving ACT medicines (χ2 = 39.242, p < 0.0001), and patient ever shared ACT medicines (χ2 = 30.893, p < 0.0001) were all associated with patients' adherence to ACT. Multivariate analysis demonstrated that adhering to ACT is 3.063 times higher for someone satisfied with getting ACT at the facility (OR = 3.063; p < 0.0001), 4.088 times for someone with history of saving ACT medicines (OR = 4.088; p < 0.0001), 2.134 times for someone who shared ACT (OR = 2.134; p = 0.03), and 2.817 times for someone with a household head (OR = 2.817; p = 0.008). Conclusion: Patients' adherence to ACT is generally good in the studied population. However, patients' tendencies to save ACT for future use and sharing among family members is a threat, amidst the benefits associated with adherence. There is a need to educate all about adherence to medicines as prescribed, and tighten government medicine supply chain to avoid stock-outs. [ABSTRACT FROM AUTHOR]

Digenetic trematodes form a major group of human parasites, affecting a large number of humans, especially in endemic foci. Over 100 species have been reported infecting humans, including blood, lung, liver and intestinal parasites. Traditionally, trematode infections have been diagnosed by parasitological methods based on the detection and the identification of eggs in different clinical samples. However, this is complicated due to the morphological similarity between eggs of different trematode species and other factors such as lack of sensitivity or ectopic locations of the parasites. Moreover, the problem is currently aggravated by migratory flows, international travel, international trade of foods and changes in alimentary habits. Although efforts have been made for the development of immunological and molecular techniques, the detection of eggs through parasitological techniques remains as the gold standard for the diagnosis of trematodiases. In the present chapter, we review the current status of knowledge on diagnostic techniques used when examining feces, urine, and sputum and also analyze the most relevant characteristics used to identify eggs with a quick key for the identification of eggs., (© 2024. The Author(s), under exclusive license to Springer Nature Switzerland AG.)