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BMJ Open Jun 2024Multiplathogen home-based self-sampling offers an opportunity to increase access to screening and treatment in endemic settings with high coinfection prevalence of...
Zipime-Weka-Schista study protocol: a longitudinal cohort study and economic evaluation of an integrated home-based approach for genital multipathogen screening in women, including female genital schistosomiasis, human papillomavirus, Trichomonas and HIV in Zambia.
INTRODUCTION
Multiplathogen home-based self-sampling offers an opportunity to increase access to screening and treatment in endemic settings with high coinfection prevalence of sexually transmitted (HIV, human papillomavirus (HPV)) and non-sexually transmitted pathogens ()). Chronic coinfections may lead to disability (female genital schistosomiasis) and death (cervical cancer). The Zipime-Weka-Schista (Do self-testing sister!) study aims to evaluate the validity, acceptability, uptake, impact and cost-effectiveness of multipathogen self-sampling for genital infections among women in Zambia.
METHODS AND ANALYSIS
This is a longitudinal cohort study aiming to enrol 2500 non-pregnant, sexually active and non-menstruating women aged 15-50 years from two districts in Zambia with 2-year follow-up. During home visits, community health workers offer HIV and self-testing and cervicovaginal self-swabs for (1) HPV by GeneXpert and, (2) DNA detection by conventional (PCR)and isothermal (recombinase polymerase assay) molecular methods. ova and circulating anodic antigen are detected in urine. At a clinic follow-up, midwives perform the same procedures and obtain hand-held colposcopic images. High-risk HPV positive women are referred for a two-quadrant cervical biopsy according to age and HIV status. A cost-effectiveness analysis is conducted in parallel.
ETHICS AND DISSEMINATION
The University of Zambia Biomedical Research Ethics Committee (UNZABREC) (reference: 1858-2021), the London School of Hygiene and Tropical Medicine (reference: 25258), Ministry of Health and local superintendents approved the study in September 2021.Written informed consent was obtained from all participants prior to enrolment. Identifiable data collected are stored securely and their confidentiality is protected in accordance with the Data Protection Act 1998.
Topics: Humans; Female; Zambia; Longitudinal Studies; Adult; Adolescent; Young Adult; Middle Aged; Cost-Benefit Analysis; Papillomavirus Infections; HIV Infections; Mass Screening; Coinfection; Self-Testing; Animals; Schistosomiasis haematobia; Trichomonas Vaginitis; Trichomonas vaginalis; Uterine Cervical Neoplasms; Human Papillomavirus Viruses
PubMed: 38858160
DOI: 10.1136/bmjopen-2023-080395 -
PLOS Global Public Health 2024Soil transmitted helminthiasis (STH), Schistosoma haematobium and malaria co-infection lead to increased susceptibility to other infections and poor pregnancy outcomes...
Soil transmitted helminthiasis (STH), Schistosoma haematobium and malaria co-infection lead to increased susceptibility to other infections and poor pregnancy outcomes among women of reproductive age (WRA). This study sought to establish risk factors, burden of co-infection with STH, S. haematobium and Plasmodium sp. among WRA in Kilifi County, Kenya.A mixed method cross-sectional study was conducted on 474 WRA in 2021. Simple random sampling was used to select WRA from four villages in two purposively sampled sub-counties. Study participants were interviewed, and stool samples collected and analysed using Kato-Katz technique for STH. Urine samples were collected for examination of S. haematobium while malaria microscopic test was done using finger prick blood samples. Further, 15 focus group discussions (FGDs) were conducted with purposively selected WRA and qualitative data analyzed thematically using Nvivo software. Quantitative and qualitative methods were triangulated to comprehensively strengthen the study findings. Prevalence of S. haematobium was 22.3% (95%CI: 13.5-36.9), any STH 5.2% (95%CI: 1.9-14.3) and malaria 8.3% (95%: 3.8-18.2). Co-infections between any STH and S. haematobium was 0.8% (95%CI: 0.2-3.2) and between S. haematobium and malaria 0.8% (95%CI: 0.2-3.1). Multivariable analysis showed increased odds of any STH infections among participants in Rabai Sub-County, (aOR = 9.74; p = 0.026), businesswomen (aOR = 5.25; p<0.001), housewives (aOR = 2.78; p = 0.003), and casual laborers (aOR = 27.03; p<0.001). Qualitative analysis showed that the three parasitic diseases were common and responsible for possible causes of low birth weight, susceptibility to other infections and complications such as infertility and cancer later in life.The study demonstrated that STH, S. haematobium and malaria are still a public health problem to WRA. Some of the associated risks of infection were geographical location, socio-economic and WASH factors. Hence the need to implement integrated control efforts of the three parasitic infection.
PubMed: 38829897
DOI: 10.1371/journal.pgph.0003310 -
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 -
Tropical Medicine and Health May 2024Community and individual participation are crucial for the success of schistosomiasis control. The World Health Organization (WHO) has highlighted the importance of...
BACKGROUND
Community and individual participation are crucial for the success of schistosomiasis control. The World Health Organization (WHO) has highlighted the importance of enhanced sanitation, health education, and Mass Drug Administration (MDA) in the fight against schistosomiasis. These approaches rely on the knowledge and practices of the community to be successful; however, where the community knowledge is low and inappropriate, it hinders intervention efforts. Hence, it is essential to identify barriers and misconceptions related to awareness of schistosomiasis, sources of infection, mode of transmission, symptoms, and control measures.
METHODS
This was a mixed-method cross-sectional study involving 1200 pre-school children randomly selected and examined for Schistosoma mansoni infection using the Kato-Katz technique. All parents/guardians of selected children were enrolled for a pre-tested questionnaire survey, while 42 were engaged in focus group discussions (FGDs). The level of knowledge and awareness among parents/guardians about schistosomiasis was evaluated in relation to the infection status of their pre-school children.
RESULTS
Among pre-school children, the prevalence of intestinal schistosomiasis was 45.1% (95% CI 41.7-48.5). A majority of parents/guardians (85.5%) had heard about schistosomiasis, and this awareness was associated with the participant's level of education (OR = 0.16, 95% CI 0.08, 0.34). In addition, a positive association was observed between higher educational attainment and knowledge of the causative agent (OR = 0.69, 95% CI 0.49, 0.96). Low education level was significantly associated with limited knowledge of transmission through lake water contact (OR = 0.71, 95% CI 0.52, 0.97) and infection from the lake (OR = 0.33, 95% CI 0.19, 0.57). Notably, parents/guardians who have heard of schistosomiasis could not recognize symptoms of S. mansoni infection, such as abdominal pain (91.8%, 815/888) and blood in the stool (85.1%, 756/888). Surprisingly, 49.8% (442/888) incorrectly identified hematuria (blood in urine), a key sign of S. haematobium, but not S. mansoni, in an endemic area for S. mansoni infection. The majority (82.6%, 734/888) of parents/guardians were unaware that dams are potential infection sites, despite 53.9% (479/888) of their pre-school-aged children testing positive for schistosome infection.
CONCLUSIONS
Despite the high level of awareness of intestinal schistosomiasis in the study area, we identified a low level of knowledge regarding its causes, modes of transmission, signs and symptoms and potential sites of transmission within the community. This study emphasizes the need for targeted educational interventions to address the misconceptions and knowledge gaps surrounding intestinal schistosomiasis through tailored community-based programs.
PubMed: 38745247
DOI: 10.1186/s41182-024-00602-7 -
Parasites & Vectors May 2024Schistosomiasis is a neglected tropical disease that afflicts millions of people worldwide; it is caused by Schistosoma, the only dioecious flukes with ZW systems....
BACKGROUND
Schistosomiasis is a neglected tropical disease that afflicts millions of people worldwide; it is caused by Schistosoma, the only dioecious flukes with ZW systems. Schistosoma japonicum is endemic to Asia; the Z chromosome of S. japonicum comprises one-quarter of the entire genome. Detection of positive selection using resequencing data to understand adaptive evolution has been applied to a variety of pathogens, including S. japonicum. However, the contribution of the Z chromosome to evolution and adaptation is often neglected.
METHODS
We obtained 1,077,526 high-quality SNPs on the Z chromosome in 72 S. japonicum using re-sequencing data publicly. To examine the faster Z effect, we compared the sequence divergence of S. japonicum with two closely related species, Schistosoma haematobium and S. mansoni. Genetic diversity was compared between the Z chromosome and autosomes in S. japonicum by calculating the nucleotide diversity (π) and Dxy values. Population structure was also assessed based on PCA and structure analysis. Besides, we employed multiple methods including Tajima's D, F, iHS, XP-EHH, and CMS to detect positive selection signals on the Z chromosome. Further RNAi knockdown experiments were performed to investigate the potential biological functions of the candidate genes.
RESULTS
Our study found that the Z chromosome of S. japonicum showed faster evolution and more pronounced genetic divergence than autosomes, although the effect may be smaller than the variation among genes. Compared with autosomes, the Z chromosome in S. japonicum had a more pronounced genetic divergence of sub-populations. Notably, we identified a set of candidate genes associated with host-parasite co-evolution. In particular, LCAT exhibited significant selection signals within the Taiwan population. Further RNA interference experiments suggested that LCAT is necessary for S. japonicum survival and propagation in the definitive host. In addition, we identified several genes related to the specificity of the intermediate host in the C-M population, including Rab6 and VCP, which are involved in adaptive immune evasion to the host.
CONCLUSIONS
Our study provides valuable insights into the adaptive evolution of the Z chromosome in S. japonicum and further advances our understanding of the co-evolution of this medically important parasite and its hosts.
Topics: Animals; Schistosoma japonicum; Genetic Variation; Host-Parasite Interactions; Evolution, Molecular; Polymorphism, Single Nucleotide; Sex Chromosomes; Selection, Genetic; Schistosoma haematobium; Schistosoma mansoni; Biological Evolution; Schistosomiasis japonica
PubMed: 38720339
DOI: 10.1186/s13071-024-06250-4 -
PLoS Neglected Tropical Diseases May 2024Female genital schistosomiasis (FGS), caused by the parasite Schistosoma haematobium (Sh), is prevalent in Sub-Saharan Africa. FGS is associated with sexual dysfunction...
Female genital schistosomiasis burden and risk factors in two endemic areas in Malawi nested in the Morbidity Operational Research for Bilharziasis Implementation Decisions (MORBID) cross-sectional study.
BACKGROUND
Female genital schistosomiasis (FGS), caused by the parasite Schistosoma haematobium (Sh), is prevalent in Sub-Saharan Africa. FGS is associated with sexual dysfunction and reproductive morbidity, and increased prevalence of HIV and cervical precancerous lesions. Lack of approved guidelines for FGS screening and diagnosis hinder accurate disease burden estimation. This study evaluated FGS burden in two Sh-endemic areas in Southern Malawi by visual and molecular diagnostic methods.
METHODOLOGY/PRINCIPAL FINDINGS
Women aged 15-65, sexually active, not menstruating, or pregnant, were enrolled from the MORBID study. A midwife completed a questionnaire, obtained cervicovaginal swab and lavage, and assessed FGS-associated genital lesions using hand-held colposcopy. 'Visual-FGS' was defined as specific genital lesions. 'Molecular-FGS' was defined as Sh DNA detected by real-time PCR from swabs. Microscopy detected urinary Sh egg-patent infection. In total, 950 women completed the questionnaire (median age 27, [IQR] 20-38). Visual-and molecular-FGS prevalence were 26·9% (260/967) and 8·2% (78/942), respectively. 6·5% of women with available genital and urinary samples (38/584) had egg-patent Sh infection. There was a positive significant association between molecular- and visual-FGS (AOR = 2·9, 95%CI 1·7-5·0). 'Molecular-FGS' was associated with egg-patent Sh infection (AOR = 7·5, 95% CI 3·27-17·2). Some villages had high 'molecular-FGS' prevalence, despite <10% prevalence of urinary Sh among school-age children.
CONCLUSIONS/SIGNIFICANCE
Southern Malawi carries an under-recognized FGS burden. FGS was detectable in villages not eligible for schistosomiasis control strategies, potentially leaving girls and women untreated under current WHO guidelines. Validated field-deployable methods could be considered for new control strategies.
Topics: Humans; Female; Malawi; Adult; Cross-Sectional Studies; Adolescent; Schistosomiasis haematobia; Young Adult; Middle Aged; Risk Factors; Schistosoma haematobium; Animals; Aged; Prevalence; Surveys and Questionnaires; Endemic Diseases
PubMed: 38718065
DOI: 10.1371/journal.pntd.0012102 -
Infectious Diseases of Poverty May 2024The three most important genera of snails for the transmission of schistosomes are Bulinus, Biomphalaria and Oncomelania. Each of these genera, found in two distantly...
The three most important genera of snails for the transmission of schistosomes are Bulinus, Biomphalaria and Oncomelania. Each of these genera, found in two distantly related families, includes species that act as the intermediate host for one of the three most widespread schistosome species infecting humans, Schistosoma haematobium, S. mansoni and S. japonicum, respectively. An important step in the fight against schistosomiasis in Asia has been taken with the publication of the article "Chromosome-level genome assembly of Oncomelania hupensis: the intermediate snail host of Schistosoma japonicum", which means that genomes for all three major genera, including species across three continents, are now available in the public domain. This includes the first genomes of African snail vectors, namely Biomphalaria sudanica, Bi. pfeifferi and Bulinus truncatus, as well as high-quality chromosome level assemblies for South American Bi. glabrata. Most importantly, the wealth of new genomic and transcriptomic data is helping to establish the specific molecular mechanisms that underly compatibility between snails and their schistosomes, which although diverse and complex, may help to identify potential targets dictating host parasite interactions that can be utilised in future transmission control strategies. This new work on Oncomelania hupensis and indeed studies on other snail vectors, which provide deep insights into the genome, will stimulate research that may well lead to new and much needed control interventions.
Topics: Animals; Humans; Disease Vectors; Genomics; Host-Parasite Interactions; Schistosomiasis; Snails
PubMed: 38711151
DOI: 10.1186/s40249-024-01199-z -
Diagnostics (Basel, Switzerland) Apr 2024A laboratory-based lateral flow (LF) test that utilizes up-converting reporter particles (UCP) for ultrasensitive quantification of circulating anodic antigen (CAA) in...
A laboratory-based lateral flow (LF) test that utilizes up-converting reporter particles (UCP) for ultrasensitive quantification of circulating anodic antigen (CAA) in urine is a well-accepted test to identify active infection. However, this UCP-LF CAA test requires sample pre-treatment steps not compatible with field applications. Flow, a new low-cost disposable, allows integration of large-volume pre-concentration of urine analytes and LF detection into a single field-deployable device. We assessed a prototype Flow- (Flow-S) device with an integrated UCP-LF CAA test strip, omitting all laboratory-based steps, to enable diagnosis of active infection in the field using urine. Flow-S is designed for large-volume (5-20 mL) urine, applying passive paper-based filtration and antibody-based CAA concentration. Samples tested for schistosome infection were collected from women of reproductive age living in a Tanzania region where infection is endemic. Fifteen negative and fifteen positive urine samples, selected based on CAA levels quantified in paired serum, were analyzed with the prototype Flow-S. The current Flow-S prototype, with an analytical lower detection limit of 1 pg CAA/mL, produced results correlated with the laboratory-based UCP-LF CAA test. Urine precipitates occurred in frozen banked samples and affected accurate quantification; however, this should not occur in fresh urine. Based on the findings of this study, Flow-S appears suitable to replace the urine pre-treatment required for the laboratory-based UCP-LF CAA test, thus allowing true field-based applications with fresh urine samples. The urine precipitates observed with frozen samples, though less important given the goal of testing fresh urines, warrant additional investigation to evaluate methods for mitigation. Flow-S devices permit testing of pooled urine samples with applications for population stratified testing. A field test with fresh urine samples, a further optimized Flow-S device, and larger statistical power has been scheduled.
PubMed: 38667466
DOI: 10.3390/diagnostics14080820 -
Open Forum Infectious Diseases Apr 2024Reasons for the high prevalence of Kaposi sarcoma-associated herpesvirus (KSHV) in sub-Saharan Africa, and risk factors leading to viral reactivation and shedding,...
BACKGROUND
Reasons for the high prevalence of Kaposi sarcoma-associated herpesvirus (KSHV) in sub-Saharan Africa, and risk factors leading to viral reactivation and shedding, remain largely undefined. Preliminary studies have suggested that schistosome infection, which has been associated with impaired viral control, is associated with KSHV. In this study we sought to determine the relationship between active or infection and KSHV shedding.
METHODS
We quantified KSHV DNA in saliva and cervical swabs from 2 cohorts of women living in northwestern Tanzanian communities endemic for or by real-time polymerase chain reaction. χ and Fisher exact tests were used to determine differences in clinical and demographic factors between those who were and were not shedding KSHV.
RESULTS
Among 139 total women, 44.6% were KSHV seropositive. Six percent of those with and 17.1% of those with were actively shedding KSHV in saliva and none in cervical samples. Women from the cohort who were shedding virus reported infertility more frequently (80% vs 19.5%, = .009). There was no difference in frequency of KSHV salivary shedding between schistosome-infected and -uninfected women.
CONCLUSIONS
In an area with high KSHV seroprevalence and endemic schistosome infections, we provide the first report with data demonstrating no association between schistosome infection and salivary or cervical herpesvirus shedding. KSHV salivary shedding was associated with infertility, a known effect of another herpesvirus, human herpesvirus 6.
PubMed: 38654970
DOI: 10.1093/ofid/ofae161 -
Iranian Journal of Parasitology 2024Schistosomiasis is a parasitic disease caused by trematodes (body flukes), affecting millions worldwide. However, its pulmonary manifestations are rare. We report a rare...
Schistosomiasis is a parasitic disease caused by trematodes (body flukes), affecting millions worldwide. However, its pulmonary manifestations are rare. We report a rare case of a 51-year-old People Living with HIV male, managed in a tertiary care hospital in west India in May 2023, vegetable vendor who was admitted with complaints of dysphagia, odynophagia, fever and chest pain for 3 days, cough and breathlessness for 1 month. Chest x-ray and CT scan were suggestive of hypodense fluid collection with rim enhancement along right lateral and posterior aspect of thoracic esophagus. All routine investigations and urine cultures were sent, which turned to be inconclusive. Upper Gastrointestinal scopy was suggestive of pangastritis. Fiberoptic bronchoscopy was done with no structural abnormality or endobronchial mass. Bronchoalveolar lavage from right lower lobe was sent for CBNAAT, Gram and Ziehl Nelson staining and cultures, acid fast bacilli cultures and cytology which revealed parasitic infection with . The patient was treated with tablet praziquantel P/O 2400 mg in divided doses for 1 day followed up after two weeks when he experienced reduced symptoms. Sputum examination was repeated showed on wet mount and hence a repeat dose of tablet praziquantel 3000 mg in divided doses was given and was advised to follow up 2 weeks later, which showed resolution of right lower zone opacities.
PubMed: 38654948
DOI: 10.18502/ijpa.v19i1.15219