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Parasite Epidemiology and Control Nov 2023World Health Organization (WHO) recommends periodic praziquantel Mass Drug Administration (MDA) to vulnerable populations, especially school-aged children, to reduce the...
BACKGROUND
World Health Organization (WHO) recommends periodic praziquantel Mass Drug Administration (MDA) to vulnerable populations, especially school-aged children, to reduce the risk of transmission. In the endemic Lindi region, on the southeastern coast of Tanzania, praziquantel has been distributed for more than a decade (12 rounds) in schools. However, there is a paucity of data on the current burden and factors perpetuating ongoing urogenital schistosomiasis among SAC. The study investigated the prevalence and factors associated with the ongoing transmission of among school-age children (SAC) after 12 rounds of praziquantel in Nachingwea, Southern Tanzania.
MATERIAL AND METHODS
A quantitative cross-sectional study was conducted between May and June 2022 among 483 SAC in the Nachingwea district. Macrohematuria, microhaematuria, and eggs were assessed in the collected urine sample for each participant, using macroscopic observation, urine dipstick, and urine filtration techniques, respectively. Infection intensity was quantified for positive urine samples. Knowledge and attitudes towards schistosomiasis were assessed among participants through an interview-administered questionnaire, and water contact practices were registered through an observation checklist. Data were summarized using descriptive statistics, the Chi-square test, and logistic regression.
RESULTS
The prevalence of infection was 10.6%, with 0.6% (3/51) prevalence of heavy infection. The factors associated with persistence transmission were a habit of visiting the water bodies (AOR = 1.62, 95% CI: 0.40-1.96), swimming in the visited water bodies (AOR = 4.58, 95% CI: 1.72-12.19), using water from the river source (AOR = 3.79, 95% CI: 1.51-9.51) and attending Mkumba Primary School (17.4%; AOR = 6.12, 95% CI: 1.64-22.85).
CONCLUSIONS
Findings suggest ongoing transmission of urogenital schistosomiasis in the Nachingwea District despite 12 rounds of praziquantel treatment, with a low prevalence of heavy infection (0.6%). Praziquantel distribution should be complemented with health education, especially on the cause and transmission of urogenital schistosomiasis to increase knowledge that will improve a good attitude towards schistosomiasis prevention. An adequate water supply is to be considered to reduce infections due to the visit to water sources for daily use.
PubMed: 37692460
DOI: 10.1016/j.parepi.2023.e00323 -
Heliyon Dec 2023Rapid diagnosis of urogenital schistosomiasis caused by requires an accurate and timely assay, especially for low-intensity infection cases and in non-endemic areas....
Rapid diagnosis of urogenital schistosomiasis caused by requires an accurate and timely assay, especially for low-intensity infection cases and in non-endemic areas. The mitochondrial cytochrome oxidase 1 (cox1) gene fragment of was selected as detection target as this short fragment, which can be rapidly sequenced and yet possess good diagnostic resolution. A pair of primers and a fluorescent probe were designed according to the principle of recombinase-aided amplification (RAA), which was subsequently optimized and applied as an -specific RAA assay. Its diagnostic performance was validated for sensitivity and specificity in comparison to microscopy-based egg counting after urine filtration. The RAA assay could detect as little as 10 copies/μL of recombinant plasmid, and no cross-reactions were observed with , , , or . This test can be conducted at 39 °C and the whole RAA reaction can be completed within 20 min. The validation of the RAA assay showed that it had 100 % consistency with urine-egg microscopy, as it does not require an elaborate reading tool, is simple to use, and should be useful for field diagnostics and point-of-care applications.
PubMed: 38144328
DOI: 10.1016/j.heliyon.2023.e23031 -
Diagnostics (Basel, Switzerland) May 2024Urine filtration microscopy (UFM) lacks sensitivity in detecting low-intensity infections. In pursuit of a superior alternative, this study evaluated the performance of...
Urine filtration microscopy (UFM) lacks sensitivity in detecting low-intensity infections. In pursuit of a superior alternative, this study evaluated the performance of FlukeCatcher microscopy (FCM) at detecting eggs in human urine samples. Urine samples were collected from 572 school-age children in Afar, Ethiopia in July 2023 and examined using UFM and FCM approaches. Using the combined UFM and FCM results as a reference, the sensitivity, negative predictive value, and agreement levels for the two testing methods in detecting eggs in urine samples were calculated. The sensitivity and negative predictive value of detecting eggs in urine samples for FCM was 84% and 97%, respectively, compared to 65% and 93% for UFM. The FCM test results had an agreement of 61% with the UFM results, compared to 90% with the combined results of FCM and UFM. However, the average egg count estimates were lower when using FCM (6.6 eggs per 10 mL) compared to UFM (14.7 eggs per 10 mL) ( < 0.0001). Incorporating FCM into specimen processing could improve the diagnosis of infection but may underperform in characterizing the intensity of infection.
PubMed: 38786335
DOI: 10.3390/diagnostics14101037 -
PLoS Pathogens Jul 2023Schistosomiasis, a severe parasitic disease, is primarily caused by Schistosoma mansoni, Schistosoma japonicum, or Schistosoma haematobium. Currently, praziquantel is... (Review)
Review
Schistosomiasis, a severe parasitic disease, is primarily caused by Schistosoma mansoni, Schistosoma japonicum, or Schistosoma haematobium. Currently, praziquantel is the only recommended drug for human schistosome infection. However, the lack of efficacy of praziquantel against juvenile worms and concerns about the emergence of drug resistance are driving forces behind the research for an alternative medication. Schistosomes are obligatory parasites that survive on nutrients obtained from their host. The ability of nutrient uptake depends on their physiological structure. In short, the formation and maintenance of the structure and nutrient supply are mutually reinforcing and interdependent. In this review, we focus on the structural features of the tegument, esophagus, and intestine of schistosomes and their roles in nutrient acquisition. Moreover, we introduce the significance and modes of glucose, lipids, proteins, and amino acids intake in schistosomes. We linked the schistosome structure and nutrient supply, introduced the currently emerging targets, and analyzed the current bottlenecks in the research and development of drugs and vaccines, in the hope of providing new strategies for the prevention and control of schistosomiasis.
Topics: Animals; Humans; Praziquantel; Schistosomiasis; Schistosoma japonicum; Schistosoma haematobium; Schistosoma mansoni; Eating
PubMed: 37498810
DOI: 10.1371/journal.ppat.1011498 -
Journal of Parasitology Research 2023Anaemia is common in sub-Saharan Africa, and parasitic infections could worsen its burden during pregnancy. Moreover, women become susceptible to malaria during...
BACKGROUND
Anaemia is common in sub-Saharan Africa, and parasitic infections could worsen its burden during pregnancy. Moreover, women become susceptible to malaria during pregnancy. We investigated () and () infections and determined their association with anaemia during pregnancy.
METHODS
A cross-sectional study involving 707 pregnant women attending antenatal care visits (ANC) and 446 at delivery was conducted in Battor and Adidome hospitals. Pregnant women were screened by microscopy and qPCR for and infections. Haemoglobin (Hb) levels were determined, and most participants received intermittent preventive treatment during pregnancy (IPTp) during ANC till delivery. Regression analyses were performed for associations between parasite infection and anaemia.
RESULTS
microscopy prevalence at ANC and delivery was 8% and 2%, respectively, and by PCR 24% at ANC and 12% at delivery. Anaemia prevalence at ANC was 52% and 49% at delivery. There was an increased risk of anaemia with infection (aOR = 1.92; = 0.04). IPTp ( = 0.003) and age ( = 0.004) were associated with increased Hb levels at delivery. prevalence by microscopy was 4% at ANC and 2% at delivery. No significant correlation between and Hb levels was observed (coef. = -0.62 g/dl; = 0.07).
CONCLUSION
High anaemia prevalence was observed during pregnancy, and infection was associated with anaemia at ANC. Low prevalence could be attributed to previous praziquantel treatment during mass drug administration. Routine diagnosis and treatment of infections in endemic areas could be initiated to reduce schistosomiasis during pregnancy.
PubMed: 37808169
DOI: 10.1155/2023/7500676 -
Parasites & Vectors Aug 2023Although schistosomiasis is a public health issue in Mali, little is known about the parasite genetic profile. The purpose of this study was to analyze the genetic...
BACKGROUND
Although schistosomiasis is a public health issue in Mali, little is known about the parasite genetic profile. The purpose of this study was to analyze the genetic profile of the schistosomes of Schistosoma haematobium group in school-aged children in various sites in Mali.
METHODS
Urine samples were collected from 7 to 21 November 2021 and subjected to a filtration method for the presence S. haematobium eggs. The study took place in two schistosomiasis endemic villages (Fangouné Bamanan and Diakalèl), qualified as hotspots according to the World Health Organization (WHO) definition. Molecular genotyping on both Cox1 and ITS2/18S was used for eggs' taxonomic assignation.
RESULTS
A total of 970 miracidia were individually collected from 63 school-aged children and stored on Whatman FTA cards for molecular analysis. After genotyping 42.0% (353/840) and 58.0% (487/840) of miracidia revealed Schistosoma bovis and S. haematobium Cox1 profiles, respectively; 95.7 (885/925) and 4.3% (40/925) revealed S. haematobium and S. haematobium/S. curassoni profiles for ITS/18S genes, respectively. There was a significant difference in the Cox1 and ITS2/18S profile distribution according to the village (P < 0.0001). Overall, 45.6% (360/789) were hybrids, of which 72.0% (322/447) were from Diakalèl. Three hybrids' profiles (Sb/Sc_ShxSc with 2.3%; Sb/Sc_ShxSh with 40.5%; Sh_ShxSc with 2.8%) and one pure profile (Sh_ShxSh with 54.4%) were identified.
CONCLUSION
Our findings show, for the first time to our knowledge, high prevalence of hybrid schistosomes in Mali. More studies are needed on population genetics of schistosomes at the human and animal interface to evaluate the parasite's gene flow and its consequences on epidemiology of the disease as well as the transmission to humans.
Topics: Child; Animals; Humans; Schistosoma haematobium; Parasites; Disease Hotspot; Genetic Profile; Schistosoma; Schistosomiasis; Schistosomiasis haematobia
PubMed: 37542265
DOI: 10.1186/s13071-023-05860-8 -
The Pan African Medical Journal 2023schistosomiasis is a neglected tropical disease and remains a disease of public health concern. Despite its relative importance, paucity of information on...
INTRODUCTION
schistosomiasis is a neglected tropical disease and remains a disease of public health concern. Despite its relative importance, paucity of information on schistosomiasis in urban settings such as Ndola remains. Here, we present findings on the prevalence and factors associated with Schistosoma haematobium (S. haematobium) infections among School-going children in the Kawama in Ndola district in Zambia, an urban area in the Copperbelt Province, Zambia.
METHODS
we employed a cross-sectional study design among 354 school going-children between 5 and 17 years of age between November 2020 and February 2021. A Multivariate forward step-wise logistic regression model was used to determine the associations of risk factors. Adjusted odds ratios and 95% confidence intervals are reported.
RESULTS
of the 354 school-going children included in the analysis, 13.3% had S. haematobium infection. Children who swam in the stream/dam were more likely to have S. haematobium infection as compared to those who did not (aOR 6.531, 95% CI: 2.90-14.69).
CONCLUSION
S. haematobium infection is endemic among school-going children in an urban setup of the Kawama area of Ndola City, Zambia. There is a need for targeted interventions to mitigate infections among this population.
Topics: Animals; Humans; Schistosoma haematobium; Prevalence; Zambia; Cross-Sectional Studies; Schistosomiasis haematobia
PubMed: 37900207
DOI: 10.11604/pamj.2023.45.170.41193 -
Pathogens (Basel, Switzerland) Jul 2023Medical complications during pregnancy have been frequently reported from Western Africa with a particular importance of infectious complications. Placental tissue can...
Screening for Resistant Bacteria, Antimicrobial Resistance Genes, Sexually Transmitted Infections and spp. in Tissue Samples from Predominantly Vaginally Delivered Placentae in Ivory Coast and Ghana.
Medical complications during pregnancy have been frequently reported from Western Africa with a particular importance of infectious complications. Placental tissue can either become the target of infectious agents itself, such as, e.g., in the case of urogenital schistosomiasis, or be subjected to contamination with colonizing or infection-associated microorganisms of the cervix or the vagina during vaginal delivery. In the retrospective cross-sectional assessment presented here, the quantitative dimension of infection or colonization with selected resistant or pathogenic bacteria and parasites was regionally assessed. To do so, 274 collected placental tissues from Ivory Coastal and Ghanaian women were subjected to selective growth of resistant bacteria, as well as to molecular screening for beta-lactamase genes, spp. and selected bacterial causative agents of sexually transmitted infections (STI). Panton-Valentine-negative methicillin-resistant (MRSA) was grown from 1.8% of the tissue samples, comprising the types t008 and t688, as well as the newly detected ones, t12101 (n = 2) and t12102. While the culture-based recovery of resistant Enterobacterales and nonfermentative rod-shaped Gram-negative bacteria failed, molecular assessments confirmed beta-lactamase genes in 31.0% of the samples with multiple detections of up to four resistance genes per sample and , , , , -like, , -like, -like and occurring in descending order of frequency. The beta-lactamase genes -like, , , , and were not detected. DNA of the urogenital schistosomiasis-associated complex was recorded in 18.6% of the samples, but only a single positive signal for with a high cycle-threshold value in real-time PCR was found. Of note, higher rates of schistosomiasis were observed in Ghana (54.9% vs. 10.3% in Ivory Coast) and Cesarean section was much more frequent in schistosomiasis patients (61.9% vs. 14.8% in women without spp. DNA in the placenta). Nucleic acid sequences of nonlymphogranuloma-venereum-associated and of were recorded in 1.1% and 1.9% of the samples, respectively, while molecular attempts to diagnose and did not lead to positive results. Molecular detection of spp. or STI-associated pathogens was only exceptionally associated with multiple resistance gene detections in the same sample, suggesting epidemiological distinctness. In conclusion, the assessment confirmed considerable prevalence of urogenital schistosomiasis and resistant bacterial colonization, as well as a regionally expected abundance of STI-associated pathogens. Continuous screening offers seem advisable to minimize the risks for the pregnant women and their newborns.
PubMed: 37623959
DOI: 10.3390/pathogens12080999 -
PLoS Pathogens Jul 2023Human schistosomiasis is a neglected tropical disease caused by Schistosoma mansoni, S. haematobium, and S. japonicum. Praziquantel (PZQ) is the method of choice for...
Human schistosomiasis is a neglected tropical disease caused by Schistosoma mansoni, S. haematobium, and S. japonicum. Praziquantel (PZQ) is the method of choice for treatment. Due to constant selection pressure, there is an urgent need for new therapies for schistosomiasis. Previous treatment of S. mansoni included the use of oxamniquine (OXA), a drug that is activated by a schistosome sulfotransferase (SULT). Guided by data from X-ray crystallography and Schistosoma killing assays more than 350 OXA derivatives were designed, synthesized, and tested. We were able to identify CIDD-0150610 and CIDD-0150303 as potent derivatives in vitro that kill (100%) of all three Schistosoma species at a final concentration of 71.5 μM. We evaluated the efficacy of the best OXA derivates in an in vivo model after treatment with a single dose of 100 mg/kg by oral gavage. The highest rate of worm burden reduction was achieved by CIDD -150303 (81.8%) against S. mansoni, CIDD-0149830 (80.2%) against S. haematobium and CIDD-066790 (86.7%) against S. japonicum. We have also evaluated the ability of the derivatives to kill immature stages since PZQ does not kill immature schistosomes. CIDD-0150303 demonstrated (100%) killing for all life stages at a final concentration of 143 μM in vitro and effective reduction in worm burden in vivo against S. mansoni. To understand how OXA derivatives fit in the SULT binding pocket, X-ray crystal structures of CIDD-0150303 and CIDD-0150610 demonstrate that the SULT active site will accommodate further modifications to our most active compounds as we fine tune them to increase favorable pharmacokinetic properties. Treatment with a single dose of 100 mg/kg by oral gavage with co-dose of PZQ + CIDD-0150303 reduced the worm burden of PZQ resistant parasites in an animal model by 90.8%. Therefore, we conclude that CIDD-0150303, CIDD-0149830 and CIDD-066790 are novel drugs that overcome some of PZQ limitations, and CIDD-0150303 can be used with PZQ in combination therapy.
Topics: Animals; Humans; Praziquantel; Oxamniquine; Schistosomiasis; Schistosoma mansoni; Combined Modality Therapy; Neglected Diseases; Schistosomiasis mansoni; Anthelmintics
PubMed: 37428793
DOI: 10.1371/journal.ppat.1011018 -
Pathogens (Basel, Switzerland) Jan 2024Schistosomiasis is a bloodborne, and waterborne parasitic disease caused by the human species, namely and . The parasite requires an intermediate snail host, where...
Schistosomiasis is a bloodborne, and waterborne parasitic disease caused by the human species, namely and . The parasite requires an intermediate snail host, where they grow and develop, along with a human host (definitive). egg detection in feces () and urine () are the WHO-recommended confirmatory diagnostic tests. The goal of our research was to determine the efficacy of detecting single or dual Schistosome species from filtered human urine samples collected in Tanzania by amplifying species-specific cell-free repeat DNA fragments via polymerase chain reaction (PCR) and gel electrophoresis. In total, 104 filtered human urine samples were evaluated and collected from individuals residing in the village of Kayenze, Tanzania. All samples were detected with 100% accuracy and no cross-amplification was present. For a single infection of , 22 (21%) of the samples were positive, while 15 (14%) of the samples were negative via PCR. Moreover, for a single infection of , 7 (7%) of the samples were positive, while 15 (14%) of the samples were negative. Dual infections were found in a higher percentage, with 60 (58%) of the samples being positive. Thus, we have justified that PCR is more sensitive and specific by amplifying species-specific cell-free repeat DNA fragments from the same urine sample than WHO-recommended methods of processing stool and urine.
PubMed: 38251366
DOI: 10.3390/pathogens13010059