The global burden of disease study 2013: What does it mean for the NTDs?

Highlighting the Relevance of CD8+ T Cells in Filarial Infections

The T cell immune responses in filarial infections are primarily mediated by CD4+ T cells and type 2-associated cytokines. Emerging evidence indicates that CD8+ T cell responses are important for anti-filarial immunity, however, could be suppressed in co-infections. This review summarizes what we know so far about the activities of CD8+ T cell responses in filarial infections, co-infections, and the associations with the development of filarial pathologies.

Effect of co-infection with intestinal parasites on COVID-19 severity: A prospective observational cohort study

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection results in a spectrum of clinical presentations. Evidence from Africa indicates that significantly less COVID-19 patients suffer from serious symptoms than in the industrialized world. We and others previously postulated a partial explanation for this phenomenon, being a different, more activated immune system due to parasite infections. Here, we aimed to test this hypothesis by investigating a potential correlation of co-infection with parasites with COVID-19 severity in an endemic area in Africa. Methods: Ethiopian COVID-19 patients were enrolled and screened for intestinal parasites, between July 2020 and March 2021. The primary outcome was the proportion of patients with severe COVID-19. Ordinal logistic regression models were used to estimate the association between parasite infection, and COVID-19 severity. Models were adjusted for sex, age, residence, education level, occupation, body mass index, and comorbidities. Findings: 751 SARS-CoV-2 infected patients were enrolled, of whom 284 (37.8%) had intestinal parasitic infection. Only 27/255 (10.6%) severe COVID-19 patients were co-infected with intestinal parasites, while 257/496 (51.8%) non-severe COVID-19 patients were parasite positive (p<0.0001). Patients co-infected with parasites had lower odds of developing severe COVID-19, with an adjusted odds ratio (aOR) of 0.23 (95% CI 0.17-0.30; p<0.0001) for all parasites, aOR 0.37 ([95% CI 0.26-0.51]; p<0.0001) for protozoa, and aOR 0.26 ([95% CI 0.19-0.35]; p<0.0001) for helminths. When stratified by species, co-infection with Entamoeba spp., Hymenolepis nana, Schistosoma mansoni, and Trichuris trichiura implied lower probability of developing severe COVID-19. There were 11 deaths (1.5%), and all were among patients without parasites (p = 0.009). Interpretation: Parasite co-infection is associated with a reduced risk of severe COVID-19 in African patients. Parasite-driven immunomodulatory responses may mute hyper-inflammation associated with severe COVID-19. Funding: European and Developing Countries Clinical Trials Partnership (EDCTP) - European Union, and Joep Lange Institute (JLI), The Netherlands. Trial registration: Clinicaltrials.gov: NCT04473365.

Effect of co-infection with intestinal parasites on COVID-19 severity: A prospective observational cohort study

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection results in a spectrum of clinical presentations. Evidence from Africa indicates that significantly less COVID-19 patients suffer from serious symptoms than in the industrialized world. We and others previously postulated a partial explanation for this phenomenon, being a different, more activated immune system due to parasite infections. Here, we aimed to test this hypothesis by investigating a potential correlation of co-infection with parasites with COVID-19 severity in an endemic area in Africa. Methods: Ethiopian COVID-19 patients were enrolled and screened for intestinal parasites, between July 2020 and March 2021. The primary outcome was the proportion of patients with severe COVID-19. Ordinal logistic regression models were used to estimate the association between parasite infection, and COVID-19 severity. Models were adjusted for sex, age, residence, education level, occupation, body mass index, and comorbidities. Findings: 751 SARS-CoV-2 infected patients were enrolled, of whom 284 (37.8%) had intestinal parasitic infection. Only 27/255 (10.6%) severe COVID-19 patients were co-infected with intestinal parasites, while 257/496 (51.8%) non-severe COVID-19 patients were parasite positive (p<0.0001). Patients co-infected with parasites had lower odds of developing severe COVID-19, with an adjusted odds ratio (aOR) of 0.23 (95% CI 0.17-0.30; p<0.0001) for all parasites, aOR 0.37 ([95% CI 0.26-0.51]; p<0.0001) for protozoa, and aOR 0.26 ([95% CI 0.19-0.35]; p<0.0001) for helminths. When stratified by species, co-infection with Entamoeba spp., Hymenolepis nana, Schistosoma mansoni, and Trichuris trichiura implied lower probability of developing severe COVID-19. There were 11 deaths (1.5%), and all were among patients without parasites (p = 0.009). Interpretation: Parasite co-infection is associated with a reduced risk of severe COVID-19 in African patients. Parasite-driven immunomodulatory responses may mute hyper-inflammation associated with severe COVID-19. Funding: European and Developing Countries Clinical Trials Partnership (EDCTP) - European Union, and Joep Lange Institute (JLI), The Netherlands. Trial registration: Clinicaltrials.gov: NCT04473365.

Vaccine for a neglected tropical disease Taenia solium cysticercosis: fight for eradication against all odds

INTRODUCTION

Taenia solium infection is among the 17 most neglected tropical diseases identified by World Health Organization and to be eradicated by 2030. This parasite infects the central nervous system (Neurocysticercosis [NCC]) and intestine [Taeniasis]). NCC is the most frequent cause of acquired epilepsy in endemic regions and Taeniasis is responsible for the widespread malnutrition and abdominal discomfort among children. Epilepsy caused by T. solium is preventable and the total elimination of NCC can be achieved by good hygiene, mass therapy, and most importantly vaccination of pigs or humans. Vaccine for pig is available but not widely in use and for humans it's still elusive.

AREA COVERED

Several vaccine candidates for porcine cysticercosis have been tried like TSOL18, SP3Vac, KETc7, TSOL45, etc. with good success in the limited field trial. This review highlights some seminal contributions for the anti-cestode vaccine, the associated challenges, current status, suggestive future directions, and the need of vaccine for human use.

EXPERT OPINION

Though several vaccines are available, none is being widely used due to lack of awareness, economic constraints, accessibility, etc. Hence, there is a need for a newer, economic, and reliable vaccine for humans or pigs use to reduce the disease burden.

Axenic amastigotes of Leishmania species as a suitable model for in vitro studies

Leishmania spp. are etiological agents of infection diseases, which in some cases can be fatal. The main forms of their biological cycle, promastigotes and amastigotes, can be maintained in vitro. While promastigotes are easier to maintain, amastigotes are more complex and can be obtained through different ways, including infection assays of tissues or in vitro cells, and differentiation from promastigotes to axenic amastigotes. Several protocols have been proposed for in vitro differentiation for at least 12 Leishmania spp. of both subgenera, Leishmania and Viannia. In this review we propose a critical summary of axenic amastigotes induction, as well as the impact of these strategies on metabolic pathways and regulatory networks analyzed by omics approaches. The parameters used by different research groups show considerable variations in temperature, pH and induction stages, as highlighted here for Leishmania (Viannia) braziliensis. Therefore, a consensus on strategies for inducing amastigogenesis is necessary to improve accuracy and even define stage-specific biomarkers. In fact, the axenic amastigote model has contributed to elucidate several aspects of the parasite cycle, however, since it does not reproduce the intracellular environment, its use requires several precautions. In addition, we present a discussion about using axenic amastigotes for drug screening, suggesting the need of a more sensitive methodology to verify cell viability in these tests. Collectively, this review explores the advantages and limitations found in studies with axenic amastigotes, done for more than 30 years, and discuss the gaps that impair their use as a suitable model for in vitro studies.

Intestinal Parasitic Infections in Relation to COVID-19 in Baghdad City

BACKGROUND: COVID-19 is resulted from severe acute respiratory syndrome coronavirus 2, which initiated in China in December 2019. Parasites are efficient immune modulators because their ability to stimulate an immune response in infected persons. AIM: This study aims to detect if there is a probable relationship between intestinal parasitic infections and COVID-19. METHODS: Ninety patients consulted at Al-Kindy Teaching Hospital (Al-Shifa center) from October 2020 till April 2021, confirmed infection with COVID-19 by PCR. Stool examination was done for detecting intestinal parasites. RESULTS: From 90 patients, males were 63 (70%), with median age 32 years, while females were 27 (30%), with age 24–44 years. Asymptomatic patients were 8.1 (9%), patients with moderate symptoms 22.5 (25%) cases, while the rest were 59.4 (66%) cases who required enter to the intensive care unit, with symptoms including cough (80%), dyspnea (74%), fever (56%), headache (43%), chest pain (37%), sore throat (35%), myalgia (32%), diarrhea (27%), and hemoptysis (3%). CONCLUSION: There is inverse relationship between parasitic infection and COVID-19 infections, and it is significant to understand the action between parasites and microbiome, also its function in COVID-19 pathogenicity.

Current Epidemiological Characteristics of Imported Malaria, Vector Control Status and Malaria Elimination Prospects in the Gulf Cooperation Council (GCC) Countries

Malaria is the most common vector-borne parasitic infection causing significant human morbidity and mortality in nearly 90 tropical/sub-tropical countries worldwide. Significant differences exist in the incidence of malaria cases, dominant Plasmodium species, drug-resistant strains and mortality rates in different countries. Six Gulf Cooperation Council (GCC) countries (Bahrain, Kuwait, Qatar, Oman, Saudi Arabia and United Arab Emirates, UAE) in the Middle East region with similar climates, population demographics and economic prosperity are aiming to achieve malaria elimination. In this narrative review, all studies indexed in PubMed describing epidemiological characteristics of indigenous and imported malaria cases, vector control status and how malaria infections can be controlled to achieve malaria elimination in GCC countries were reviewed and discussed. These studies have shown that indigenous malaria cases are absent in Bahrain, Kuwait, Qatar and UAE and have progressively declined in Oman and Saudi Arabia. However, imported malaria cases continue to occur as GCC countries have large expatriate populations originating from malaria-endemic countries. Various malaria control and prevention strategies adopted by GCC countries including more stringent measures to reduce the likelihood of importing malaria cases by prior screening of newly arriving expatriates and vector elimination programs are likely to lead to malaria elimination in this region.

Size-asymmetric competition among snails disrupts production of human-infectious Schistosoma mansoni cercariae

Parasites can harm hosts and influence populations, communities, and ecosystems. However, parasites are reciprocally affected by population- and community-level dynamics. Understanding feedbacks between infection dynamics and larger-scale epidemiological and ecological processes could improve predictions and reveal novel control methods. We evaluated how exploitative resource competition among hosts, a fundamental aspect of population biology, influences within-host infection dynamics of the widespread human parasite Schistosoma mansoni in its intermediate host, Biomphalaria glabrata. We added size-dependent consumption of shared resources to a parameterized bioenergetics model to predict a priori the growth, parasite production, and survival of an infected focal host coexisting with an uninfected conspecific competitor in an experiment that varied competitor size. The model quantitatively anticipated that competitors disrupt growth and parasite production and that these effects increase with competitor size. Fitting the model to these data improved its match to host survivorship. Thus, resource competition alters infection dynamics, there are strong size asymmetries in these effects, and size-asymmetric resource competition effects on infection dynamics can be accurately predicted by bioenergetics theory. More broadly, this framework can assess parasite transmission and control in other contexts, such as in resource competitive host communities, or in response to eutrophication, food supplementation, or culling.

Immune Response to the Enteric Parasite Entamoeba histolytica

Entamoeba histolytica is a protozoan parasite responsible for amoebiasis, a disease with a high prevalence in developing countries. Establishing an amoebic infection involves interplay between pathogenic factors for invasion and tissue damage, and immune responses for protecting the host. Here, we review the pathogenicity of E. histolytica and summarize the latest knowledge on immune response and immune evasion mechanisms during amoebiasis.

Alkaloids in Contemporary Drug Discovery to Meet Global Disease Needs

An overview is presented of the well-established role of alkaloids in drug discovery, the application of more sustainable chemicals, and biological approaches, and the implementation of information systems to address the current challenges faced in meeting global disease needs. The necessity for a new international paradigm for natural product discovery and development for the treatment of multidrug resistant organisms, and rare and neglected tropical diseases in the era of the Fourth Industrial Revolution and the Quintuple Helix is discussed.

Chronic Immune Activation and CD4+ T Cell Lymphopenia in Healthy African Individuals: Perspectives for SARS-CoV-2 Vaccine Efficacy

Chronic immune activation has been considered as the driving force for CD4+ T cell depletion in people infected with HIV-1. Interestingly, the normal immune profile of adult HIV-negative individuals living in Africa also exhibit chronic immune activation, reminiscent of that observed in HIV-1 infected individuals. It is characterized by increased levels of soluble immune activation markers, such as the cytokines interleukin (IL)-4, IL-10, TNF-α, and cellular activation markers including HLA-DR, CD-38, CCR5, coupled with reduced naïve and increased memory cells in CD4+ and CD8+ subsets. In addition, it is accompanied by low CD4+ T cell counts when compared to Europeans. There is also evidence that mononuclear cells from African infants secrete less innate cytokines than South and North Americans and Europeans in vitro. Chronic immune activation in Africans is linked to environmental factors such as parasitic infections and could be responsible for previously observed immune hypo-responsiveness to infections and vaccines. It is unclear whether the immunogenicity and effectiveness of anti-SARS-CoV-2 vaccines will also be reduced by similar mechanisms. A review of studies investigating this phenomenon is urgently required as they should inform the design and delivery for vaccines to be used in African populations.

Evaluation of Neighborhood Socio-Economic Status, as Measured by the Delphi Method, on Dengue Fever Distribution in Jeddah City, Saudi Arabia

Dengue fever, a mosquito-transmitted viral disease, is present in many neighborhoods in Jeddah City, Saudi Arabia. One factor likely to affect its distribution is the socio-economic status of local neighborhoods; however, the absence of socio-economic census data in Saudi Arabia has precluded detailed investigation. This study aims to develop a proxy measure of socio-economic status in Jeddah City in order to assess its relationship with the occurrence of dengue fever. The Delphi method was used to assess the socio-economic status (high, medium or low) of local neighborhoods in Jeddah City. A Geographic Information System (GIS) was applied to understand the distribution of dengue fever according to the socio-economic status of Jeddah City neighborhoods. Low-socio-economic status neighborhoods in south Jeddah City, with poor environmental conditions and high levels of poverty and population density, reported most cases of dengue fever. Nevertheless, dengue continues to increase in high socio-economic status neighborhoods in the northern part of the city, possibly due to ideal breeding conditions caused by the presence of standing water associated with high levels of construction. Moreover, the low-socioeconomic-status neighborhoods had the highest average number of cases, being 3.95 times that of high-status neighborhoods for the period 2006–2009. The Delphi approach can produce a useful and robust measure of socio-economic status for use in the analysis of patterns of dengue fever. Results suggest that there are nuances in the relationship between socio-economic status and dengue that indicate that higher status areas are also at risk. A useful additional tool for researchers in Saudi Arabia would be the development of census data or other systematic measures that allow socio-economic status to be included in spatial analyses of dengue fever and other diseases.

Neutrophils vs. amoebas: Immunity against the protozoan parasite Entamoeba histolytica

Entamoeba histolytica is a protozoan parasite with high prevalence in developing countries, and causes amoebiasis. This disease affects the intestine and the liver, and is the third leading cause of human deaths among parasite infections. E. histolytica infection of the intestine or liver is associated with a strong inflammation characterized by a large number of infiltrating neutrophils. Consequently, several reports suggest that neutrophils play a protective role in amoebiasis. However, other reports indicate that amoebas making direct contact with neutrophils provoke lysis of these leukocytes, resulting in the release of their lytic enzymes, which in turn provoke tissue damage. Therefore, the role of neutrophils in this parasitic infection remains controversial. Neutrophils migrate from the circulation to sites of infection, where they display several antimicrobial functions, including phagocytosis, degranulation, and formation of neutrophil extracellular traps (NET). Recently, it was found that E. histolytica trophozoites are capable of inducing NET formation. Neutrophils in touch with amoebas launched NET in an explosive manner around the amoebas and completely covered them in nebulous DNA and cell aggregates where parasites got immobilized and killed. In addition, the phenotype of neutrophils can be modified by the microbiome resulting in protection against amoebas. This review describes the mechanisms of E. histolytica infection and discusses the novel view of how neutrophils are involved in innate immunity defense against amoebiasis. Also, the mechanisms on how the microbiome modulates neutrophil function are described.

An outbreak of acute skin and soft tissue infections including necrotizing fasciitis in Kalwala village, India, 2018: Public health implications for the lymphatic filariasis elimination program

BACKGROUND

A cluster of 15 acute skin and soft tissue infections (SSTIs), including two cases of necrotizing fasciitis, reported in July 2018 from Kalwala village, led us to investigate and describe their epidemiology and to provide recommendations.

METHODS

Cases, defined as localized painful swelling and redness in Kalwala residents from 1 December 2017 to 20 August 2018, were identified from hospital records and house-to-house surveys. We conducted an unmatched case-control study to identify risk factors for severity. We cultured wound samples and environmental samples from wound-dressing stations.

RESULTS

We identified 36 cases (median age: 55 [range 17-80] y; 78% male), village attack rate 1% (36/4337) and no deaths. In 34 cases (94%), lower limbs were involved. Lymphatic filariasis (LF) was a common predisposing condition (67%). Comorbidities (diabetes or hypertension) (OR=9; 95% CI 2.0 to 41.1), poor limb hygiene (OR=16; 95% CI 2.8 to 95.3) and poor health-seeking behavior (OR=5; 95% CI 1.6 to 30.8) were associated with severity. All seven wound samples and 8/11 samples from wound-dressing stations showed atypical polymicrobial growth (Pseudomonas, Proteus, Klebsiella, Escherichia coli and Clostridium).

CONCLUSION

The outbreak of SSTIs among older males with LF was due to secondary bacterial infections and severity was associated with comorbidities, poor hygiene and health-seeking behavior, and likely contamination during wound-dressing. The LF elimination program managers was alerted, programmatic interventions were scaled up, home/facility-based morbidity and comorbidity management was facilitated and the outbreak was rapidly contained.

New global targets for NTDs in the WHO roadmap 2021-2030

The second World Neglected Tropical Diseases (NTDs) Day was celebrated on 30 January 2021. To mark the occasion, the World Health Organization (WHO) launched its roadmap for NTDs for the period 2021 to 2030, which is aimed at increasing prevention and control of these too-long neglected diseases. Described here is a global overview on past achievements, current challenges, and future prospects for the WHO NTDs roadmap 2021–2030.

Epidemiology of soil transmitted helminths and risk analysis of hookworm infections in the community: Results from the DeWorm3 Trial in southern India

Since 2015, India has coordinated the largest school-based deworming program globally, targeting soil-transmitted helminths (STH) in ~250 million children aged 1 to 19 years twice yearly. Despite substantial progress in reduction of morbidity associated with STH, reinfection rates in endemic communities remain high. We conducted a community based parasitological survey in Tamil Nadu as part of the DeWorm3 Project—a cluster-randomised trial evaluating the feasibility of interrupting STH transmission at three geographically distinct sites in Africa and Asia—allowing the estimation of STH prevalence and analysis of associated factors. In India, following a comprehensive census, enumerating 140,932 individuals in 36,536 households along with geospatial mapping of households, an age-stratified sample of individuals was recruited into a longitudinal monitoring cohort (December 2017-February 2018) to be followed for five years. At enrolment, a total of 6089 consenting individuals across 40 study clusters provided a single adequate stool sample for analysis using the Kato-Katz method, as well as answering a questionnaire covering individual and household level factors. The unweighted STH prevalence was 17.0% (95% confidence interval [95%CI]: 16.0–17.9%), increasing to 21.4% when weighted by age and cluster size. Hookworm was the predominant species, with a weighted infection prevalence of 21.0%, the majority of which (92.9%) were light intensity infections. Factors associated with hookworm infection were modelled using mixed-effects multilevel logistic regression for presence of infection and mixed-effects negative binomial regression for intensity. The prevalence of both Ascaris lumbricoides and Trichuris trichiura infections were rare (<1%) and risk factors were therefore not assessed. Increasing age (multivariable odds ratio [mOR] 21.4, 95%CI: 12.3–37.2, p<0.001 for adult age-groups versus pre-school children) and higher vegetation were associated with an increased odds of hookworm infection, whereas recent deworming (mOR 0.3, 95%CI: 0.2–0.5, p<0.001) and belonging to households with higher socioeconomic status (mOR 0.3, 95%CI: 0.2–0.5, p<0.001) and higher education level of the household head (mOR 0.4, 95%CI: 0.3–0.6, p<0.001) were associated with lower odds of hookworm infection in the multilevel model. The same factors were associated with intensity of infection, with the use of improved sanitation facilities also correlated to lower infection intensities (multivariable infection intensity ratio [mIIR] 0.6, 95%CI: 0.4–0.9, p<0.016). Our findings suggest that a community-based approach is required to address the high hookworm burden in adults in this setting. Socioeconomic, education and sanitation improvements alongside mass drug administration would likely accelerate the drive to elimination in these communities.

Trial Registration:NCT03014167.

Approximately 1 in 5 people in India are infected with soil transmitted helminths (STH), leading to anaemia and malnutrition. To tackle this large burden of infection, the government of India launched one of the world’s largest school-based deworming programs in 2015 aiming to deworm all pre-school and school-aged children between 1 to 19 years of age twice yearly on the National Deworming Days. Deworming programs, including those in India, are focused on pre-school aged children, school aged children and women of reproductive age group. However, prevailing environmental and socioeconomic conditions, including poor sanitation, can contribute to high rates of reinfection from untreated adults and children. The DeWorm3 Project is a cluster-randomised trial evaluating the feasibility of interrupting STH transmission with community wide deworming of all individuals aged one to 99 years of age or older. As part of the study, we conducted a parasitological survey in the Deworm3 trial site in rural Tamil Nadu. Here we present the factors associated with STH infection and burden in these communities.

Complex emergencies and the control and elimination of neglected tropical diseases in Africa: developing a practical approach for implementing safe and effective mapping and intervention strategies

Background

Complex emergencies resulting from conflict and political instability are a major challenge for national neglected tropical diseases (NTDs) control and elimination programmes, especially in sub-Saharan Africa. Currently, there are no formal guidelines for national programmes to use and plan activities in these humanitarian situations, therefore the aim of this study was to develop a new methodological approach for making decisions about the implementation of safe and effective mapping and mass drug administration (MDA) intervention strategies.

Methods

The study focussed on the 47 World Health Organization’s African Region (AFR) countries. NTD data were based on five diseases controlled by preventive chemotherapy (PC; i.e. lymphatic filariasis, onchocerciasis, schistosomiasis, soil transmitted helminths, trachoma), obtained from the WHO data portals and The Global Trachoma Atlas for 2018. Data on complex emergencies were obtained from the Armed Conflict Location and Event Data Project for 2018–2019.

NTD and conflict data were summarised and mapped. A decision tree was developed using NTD mapping, endemicity, MDA and implementing partners data, together with conflict status information at district level. South Sudan was used as a case study, given its current nexus of high NTD prevalence, incidences of conflict, and the presence of a national NTD programme and supporting partners.

Results

For the five NTDs, between 26 and 41 countries required PC, 69.2–212.7 million people were treated with coverage between 54.8–71.4%. In total 15,273 conflict events were reported including high rates of violence against civilians (29.4%), protests (28.8%), and battles (18.1%). The decision tree process included four main steps including i) information gathering ii) determine a disease mapping strategy iii) determine an MDA implementation strategy and iv) create a disease and conflict database. Based on these steps, risk maps were created. The South Sudan case study on onchocerciasis found the majority of the districts requiring mapping or MDA had a conflict event, and required specialised methods adapted to context and risk, with support from implementation partners in selected areas.

Conclusions

The paper presents a new methodological approach for implementing safe and effective mapping and intervention strategies in NTD endemic countries with ongoing complex emergencies, which will help to address challenges and make progress toward the NTD Roadmap targets of 2030.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13031-021-00356-7.

Antimicrobial resistance of ocular microbes and the role of antimicrobial peptides

Isolation of antimicrobial-resistant microbes from ocular infections may be becoming more frequent. Infections caused by these microbes can be difficult to treat and lead to poor outcomes. However, new therapies are being developed which may help improve clinical outcomes. This review examines recent reports on the isolation of antibiotic-resistant microbes from ocular infections. In addition, an overview of the development of some new antibiotic therapies is given. The recent literature regarding antibiotic use and resistance, isolation of antibiotic-resistant microbes from ocular infections and the development of potential new antibiotics that can be used to treat these infections was reviewed. Ocular microbial infections are a global public health issue as they can result in vision loss which compromises quality of life. Approximately 70 per cent of ocular infections are caused by bacteria including Chlamydia trachomatis, Staphylococcus aureus, and Pseudomonas aeruginosa and fungi such as Candida albicans, Aspergillus spp. and Fusarium spp. Resistance to first-line antibiotics such as fluoroquinolones and azoles has increased, with resistance of S. aureus isolates from the USA to fluoroquinolones reaching 32 per cent of isolates and 35 per cent being methicillin-resistant (MRSA). Lower levels of MRSA (seven per cent) were isolated by an Australian study. Antimicrobial peptides, which are broad-spectrum alternatives to antibiotics, have been tested as possible new drugs. Several have shown promise in animal models of keratitis, especially treating P. aeruginosa, S. aureus or C. albicans infections. Reports of increasing resistance of ocular isolates to mainstay antibiotics are a concern, and there is evidence that for ocular surface disease this resistance translates into worse clinical outcomes. New antibiotics are being developed, but not by large pharmaceutical companies and mostly in university research laboratories and smaller biotech companies. Antimicrobial peptides show promise in treating keratitis.

Intestinal protozoan infections shape fecal bacterial microbiota in children from Guinea-Bissau

Intestinal parasitic infections, caused by helminths and protozoa, are globally distributed and major causes of worldwide morbidity. The gut microbiota may modulate parasite virulence and host response upon infection. The complex interplay between parasites and the gut microbiota is poorly understood, partly due to sampling difficulties in remote areas with high parasite burden. In a large study of children in Guinea-Bissau, we found high prevalence of intestinal parasites. By sequencing of the 16S rRNA genes of fecal samples stored on filter paper from a total of 1,204 children, we demonstrate that the bacterial microbiota is not significantly altered by helminth infections, whereas it is shaped by the presence of both pathogenic and nonpathogenic protozoa, including Entamoeba (E.) spp. and Giardia (G.) lamblia. Within-sample diversity remains largely unaffected, whereas overall community composition is significantly affected by infection with both nonpathogenic E. coli (R2 = 0.0131, P = 0.0001) and Endolimax nana (R2 = 0.00902, P = 0.0001), and by pathogenic E. histolytica (R2 = 0.0164, P = 0.0001) and G. lamblia (R2 = 0.00676, P = 0.0001). Infections with multiple parasite species induces more pronounced shifts in microbiota community than mild ones. A total of 31 bacterial genera across all four major bacterial phyla were differentially abundant in protozoan infection as compared to noninfected individuals, including increased abundance of Prevotella, Campylobacter and two Clostridium clades, and decreased abundance of Collinsella, Lactobacillus, Ruminococcus, Veillonella and one Clostridium clade. In the present study, we demonstrate that the fecal bacterial microbiota is shaped by intestinal parasitic infection, with most pronounced associations for protozoan species. Our results provide insights into the interplay between the microbiota and intestinal parasites, which are valuable to understand infection biology and design further studies aimed at optimizing treatment strategies.

Taking the strain out of onchocerciasis? A reanalysis of blindness and transmission data does not support the existence of a savannah blinding strain of onchocerciasis in West Africa

Onchocerciasis (also known as 'river blindness'), is a neglected tropical disease (NTD) caused by the (Simulium-transmitted) filarial nematode Onchocerca volvulus. The occurrence of 'blinding' (savannah) and non-blinding (forest) parasite strains and the existence of corresponding, locally adapted Onchocerca-Simulium complexes were postulated to explain greater blindness prevalence in savannah than in forest foci. As a result, the World Health Organization (WHO) Onchocerciasis Control Programme in West Africa (OCP) focused anti-vectorial and anti-parasitic interventions in savannah endemic areas. In this paper, village-level data on blindness prevalence, microfilarial prevalence, and transmission intensity (measured by the annual transmission potential, the number of infective, L3, larvae per person per year) were extracted from 16 West-Central Africa-based publications, and analysed according to habitat (forest, forest-savannah mosaic, savannah) to test the dichotomous strain hypothesis in relation to blindness. When adjusting for sample size, there were no statistically significant differences in blindness prevalence between the habitats (one-way ANOVA, P=0.68, mean prevalence for forest=1.76±0.37 (SE); mosaic=1.49±0.38; savannah=1.89±0.26). The well-known relationship between blindness prevalence and annual transmission potential for savannah habitats was confirmed and shown to hold for (but not to be statistically different from) forest foci (excluding data from southern Côte d'Ivoire, in which blindness prevalence was significantly lower than in other West African forest communities, but which had been the focus of studies leading to the strain-blindness hypothesis that was accepted by OCP planners). We conclude that the evidence for a savannah blinding onchocerciasis strain in simple contrast with a non-blinding forest strain is equivocal. A re-appraisal of the strain hypothesis to explain patterns of ocular disease is needed to improve understanding of onchocerciasis epidemiology and disease burden estimates in the light of the WHO 2030 goals for onchocerciasis.

The impact of Neglected Tropical Diseases (NTDs) on health and wellbeing in sub-Saharan Africa (SSA): A case study of Kenya

Neglected Tropical Diseases (NTDs) remain endemic to many regions of sub-Saharan Africa (SSA) left behind by socioeconomic progress. As such, these diseases are markers of extreme poverty and inequity that are propagated by the political, economic, social, and cultural systems that affect health and wellbeing. As countries embrace and work towards achieving the Sustainable Development Goals (SDGs), the needs of such vulnerable populations need to be addressed in local and global arenas. The research uses primary qualitative data collected from five NTD endemic counties of Kenya: interviews key informants (n = 21) involved in NTD implementation programs and focus groups (n = 5) of affected individuals. Informed by theories of political ecology of health, the research focuses on post-devolution Kenya and identifies the political, economic, social, and cultural factors that propagate NTDs and their effects on health and wellbeing. Our findings indicate that structural factors such as competing political interests, health worker strikes, inadequate budgetary allocations, economic opportunity, marginalization, illiteracy, entrenched cultural norms and practices, poor access to water, sanitation and housing, all serve to propagate NTD transmission and subsequently affect the health and wellbeing of populations. As such, we recommend that post-devolution Kenya ensures local political, economic and socio-cultural structures are equitable, sensitive and responsive to the needs of all people. We also propose poverty alleviation through capacity building and empowerment as a means of tackling NTDs for sustained economic opportunity and productivity at the local and national level.

Wellbeing is currently seen as an avenue that shapes, happiness, productivity, environmental awareness, social inclusion, and justice; however, most countries presently adopting wellbeing measures are in the global north. Neglected Tropical Diseases (NTDs) significantly compromise populations’ health and well-being in the global south, causing undesirable effects on the personal, social, and economic capabilities of communities living in endemic regions. As countries work towards achieving the Sustainable Development Goals (SDGs), it is paramount that countries in the global south adopt wellbeing measures and, in doing so, capture the lived experiences of individuals experiencing inequities, particularly as these are shaped by NTDs. In sub-Saharan Africa (SSA), political and economic power manifests across different scales, determining human-environmental interaction, distribution of resources, and the transmission of infectious agents. This paper uses a political ecology of health approach to identify the political, economic, social and cultural factors that contribute to NTDs, which are among the world’s greatest global health problems. The vast majority of people bearing the burden of NTDs reside in low-income countries. Surprisingly, as the economies of the low-income countries improve to middle-income status, NTDs continue to thrive among sub-populations of low socioeconomic status because of the unequal distribution of economic gains. As a result, NTDs are found in environments characterized by poverty and income inequality, and other inequalities in access to health services, housing, safe water, and sanitation. This paper uses political ecology of health in the primarily biomedical field of NTDs to demonstrate that inequities are embedded within the broad political, socio-cultural, and economic systems that exacerbate NTD infection. The study recommends that NTD endemic countries in SSA formulate policies that enhance equity through capacity building and empowerment enhance population wellbeing.

Current Status and the Epidemiology of Malaria in the Middle East Region and Beyond

Vector-borne parasitic infectious diseases are important causes of morbidity and mortality globally. Malaria is one of the most common vector-borne parasitic infection and is caused by five Plasmodium species, namely P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi. Epidemiologically, differences in the patterns of malaria cases, causative agent, disease severity, antimicrobial resistance, and mortality exist across diverse geographical regions. The world witnessed 229 million malaria cases which resulted in 409,000 deaths in 2019 alone. Although malaria cases are reported from 87 countries globally, Africa bears the brunt of these infections and deaths as nearly 94% of total malaria cases and deaths occur in this continent, particularly in sub-Saharan Africa. Most of the Middle East Region countries are malaria-free as no indigenous cases of infection have been described in recent years. However, imported cases of malaria continue to occur as some of these countries. Indeed, the six Gulf Cooperation Council (GCC) countries have large expatriate population originating from malaria endemic countries. In this review, the current status and epidemiology of malaria in the Middle East Region countries and other malaria-endemic countries that are home to a large migrant workforce being employed in Middle East Region countries are discussed.

Diarylureas: Repositioning from Antitumor to Antimicrobials or Multi-Target Agents against New Pandemics

Antimicrobials have allowed medical advancements over several decades. However, the continuous emergence of antimicrobial resistance restricts efficacy in treating infectious diseases. In this context, the drug repositioning of already known biological active compounds to antimicrobials could represent a useful strategy. In 2002 and 2003, the SARS-CoV pandemic immobilized the Far East regions. However, the drug discovery attempts to study the virus have stopped after the crisis declined. Today’s COVID-19 pandemic could probably have been avoided if those efforts against SARS-CoV had continued. Recently, a new coronavirus variant was identified in the UK. Because of this, the search for safe and potent antimicrobials and antivirals is urgent. Apart from antiviral treatment for severe cases of COVID-19, many patients with mild disease without pneumonia or moderate disease with pneumonia have received different classes of antibiotics. Diarylureas are tyrosine kinase inhibitors well known in the art as anticancer agents, which might be useful tools for a reposition as antimicrobials. The first to come onto the market as anticancer was sorafenib, followed by some other active molecules. For this interesting class of organic compounds antimicrobial, antiviral, antithrombotic, antimalarial, and anti-inflammatory properties have been reported in the literature. These numerous properties make these compounds interesting for a new possible pandemic considering that, as well as for other viral infections also for CoVID-19, a multitarget therapeutic strategy could be favorable. This review is meant to be an overview on diarylureas, focusing on their biological activities, not dwelling on the already known antitumor activity. Quite a lot of papers present in the literature underline and highlight the importance of these molecules as versatile scaffolds for the development of new and promising antimicrobials and multitarget agents against new pandemic events.

Extracellular vesicles released from the filarial parasite Brugia malayi downregulate the host mTOR pathway

We have previously shown that the microfilarial (mf) stage of Brugia malayi can inhibit the mammalian target of rapamycin (mTOR; a conserved serine/threonine kinase critical for immune regulation and cellular growth) in human dendritic cells (DC) and we have proposed that this mTOR inhibition is associated with the DC dysfunction seen in filarial infections. Extracellular vesicles (EVs) contain many proteins and nucleic acids including microRNAs (miRNAs) that might affect a variety of intracellular pathways. Thus, EVs secreted from mf may elucidate the mechanism by which the parasite is able to modulate the host immune response during infection. EVs, purified from mf of Brugia malayi and confirmed by size through nanoparticle tracking analysis, were assessed by miRNA microarrays (accession number GSE157226) and shown to be enriched (>2-fold, p-value<0.05, FDR = 0.05) for miR100, miR71, miR34, and miR7. The microarray analysis compared mf-derived EVs and mf supernatant. After confirming their presence in EVs using qPCR for these miRNA targets, web-based target predictions (using MIRPathv3, TarBAse and MicroT-CD) predicted that miR100 targeted mTOR and its downstream regulatory protein 4E-BP1. Our previous data with live parasites demonstrated that mf downregulate the phosphorylation of mTOR and its downstream effectors. Additionally, our proteomic analysis of the mf-derived EVs revealed the presence of proteins commonly found in these vesicles (data are available via ProteomeXchange with identifier PXD021844). We confirmed internalization of mf-derived EVs by human DCs and monocytes using confocal microscopy and flow cytometry, and further demonstrated through flow cytometry, that mf-derived EVs downregulate the phosphorylation of mTOR in human monocytes (THP-1 cells) to the same degree that rapamycin (a known mTOR inhibitor) does. Our data collectively suggest that mf release EVs that interact with host cells, such as DC, to modulate host responses.

Lymphatic filariasis, a neglected tropical disease caused by parasitic worms which affects millions of individuals, represents an important public health concern due to its high morbidity that significantly diminishes quality of life. The parasite is able to establish a chronic infection by manipulating its host’s immune responses. The larval mf stage of the parasite is of particular interest as the parasites are present in the peripheral blood and in constant contact with the host’s immune cells. We decided to investigate the role of mf-derived EVs in the modulation of human antigen presenting cells during infection. We showed that mf release EVs that are similar to exosomes, and these parasite vesicles are readily internalized by human DC. The mf-derived EVs possess a unique miRNA profile and are enriched in miRNAs that can target the mTOR pathway. We have also demonstrated that purified mf-derived EVs are capable of inhibiting mTOR signaling in human monocytes. Collectively, our results suggest that mf release exosome-like vesicles that modulate the immune metabolism of host antigen presenting cells.

An Update on the Epidemiological Features of Imported Schistosomiasis and Cystic Echinococcosis in Kuwait, 2010-2018

OBJECTIVE

Kuwait is considered a non-endemic country for most parasitic infections. However, ∼70% of 4.7 million residents in Kuwait are expatriates from Asian and African countries, which are endemic for parasitic infections. Results of microbiological investigations for schistosomiasis and cystic echinococcosis (CE) performed in a reference national laboratory were retrospectively collected and analyzed to provide an insight on the epidemiology of these 2 neglected tropical diseases in Kuwait.

SUBJECTS AND METHODS

Schistosoma infection in fecal and urine specimens from suspected patients was detected by microscopy. Schistosoma and CE infections were also detected by indirect hemagglutination assays (IHAs) using blood specimens. Patients' epidemiological data were extracted from the laboratory records.

RESULTS

The overall prevalence rates of schistosomiasis and CE were 19.0 and 5.8%, respectively. Almost all schistosomiasis cases were seen among Egyptians, especially among males, and a significantly higher prevalence (p < 0.05) was seen for CE cases among the Syrian residents. A decreasing annual trend was observed for both the parasitic infections over time in Kuwait.

CONCLUSIONS

This study confirmed that schistosomiasis is not autochthonous in Kuwait, as all cases were detected among expatriates from Schistosoma-endemic countries. Our data also showed that CE remains endemic among humans and livestock in Kuwait as is also seen in other Middle Eastern countries.

Sensibilidad in vitro a benznidazol, nifurtimox y posaconazol de cepas de Trypanosoma cruzi de Paraguay

Introducción.

Trypanosoma cruzi, agente causal de la enfermedad de Chagas, exhibe una sustancial heterogeneidad fenotípica y genotípica que puede influir en las variaciones epidemiológicas y clínicas de la enfermedad, así como en la sensibilidad a los fármacos utilizados en el tratamiento.

Objetivo.

Evaluar la sensibilidad in vitro al benznidazol, el nifurtimox y el posaconazol de 40 cepas clonadas de T. cruzi de Paraguay, con distintos genotipos, huéspedes y localidades de origen.

Materiales y métodos.

En su estado epimastigote, los parásitos se incubaron en medio de cultivo LIT (Liver Infusion Tryptose) con diferentes concentraciones de cada fármaco en ensayos por triplicado. El grado de sensibilidad se estimó a partir de las concentraciones inhibitorias del 50 y el 90% (IC₅₀ e IC₉₀) y se obtuvieron los valores promedio y la desviación estándar de cada cepa y fármaco. La significación estadística entre grupos se determinó mediante análisis de varianzas con el test no paramétrico de Wilcoxon/Kruskal-Wallis y valores de p<0,05.

Resultados.

Se observó un amplio rango de respuesta a los fármacos. Se identificaron dos grupos de parásitos (A y B) con diferencias significativas en la sensibilidad al benznidazol (p<0,0001), y tres grupos (A, B, C) en cuanto a la sensibilidad al nifurtimox y el posaconazol (p<0,0001).

Conclusiones.

En general, las cepas fueron más sensibles al nifurtimox que al benznidazol y el posaconazol. Estas diferencias evidencian la heterogeneidad de las poblaciones de T cruzi que circulan en Paraguay, lo que debe considerarse en el tratamiento y el seguimiento de las personas afectadas.

Alzahrani M, Azhar EI, Amir A, Aljiffri AM, Althaqafi AO. The economic burden of dengue fever in the Kingdom of Saudi Arabia

Rapid urbanization, global trade, and the exceptionally great numbers of worldwide visitors during Hajj and Umrah have all placed the Kingdom of Saudi Arabia at a significant risk of introducing several vector-borne tropical diseases, such as dengue fever virus (DENV) infection. In this study we estimated DENV infection cost of illness (COI) in Saudi Arabia in the period 2013–2017, by processing national data including all declared cases recorded in referral centers in the western region, being the endemic region of the country. Using a statistically validated predictive model that was built on a representative sample of 717 laboratory-confirmed cases of DENV infection, direct costs, due to care-related expenditures, were estimated by applying the predictive equation to national data. However, indirect costs, which are due to productivity loss, were estimated using the human capital model based on gross domestic product adjusted for invalidity duration. Further, under-reporting was adjusted by using an expansion factor EF = 3. We observed highest estimated costs in 2016 with over US$168.5 Million total costs, including direct (US$29.0 Million) and indirect (US$139.5 Million) costs, for a total 4415 confirmed cases. The total DENV COI for the five years was estimated as US$551.0 Million for a total 15,369 patients (59.7%) out of 25,745 declared cases, resulting in an average cost of US$11 947.6 by patient. Depending on the year, productivity years loss costs accounted for 63.3% to 83.8% of the estimated total costs. Dengue has a substantial local economic burden that costs US$110.2 Million per year, stressing the urgent need for an effective national prevention strategy to perform considerable cost-savings besides reducing morbidity.

The global incidence of DENV infection has evidenced a dramatic increase in the recent two decades with a great number of cases that are misclassified or underreported. These epidemiological characteristics generate high economic costs, especially in endemic regions and countries such as Saudi Arabia. This two-phase study aimed at providing economic data that helps political efficiency and resource prioritization for dengue prevention programs, by assessing the economic burden of disease over the last five years 2013–2017. A double-method used to estimate direct costs due to care expenses and indirect costs due to productivity loss, by using a predictive and an economic model, respectively. Assuming an expansion factor of 3 to correct under-reporting, the average estimated costs of dengue illness per year in the current study was US$117.87 million. Comparison of these findings with international reports emphasized the substantial disease burden of dengue fever in Saudi Arabia. Despite some limitations, this study provided the first economic data of dengue fever infection burden in Saudi Arabia.

The Relationship Between Air Pollution and Cognitive Functions in Children and Adolescents: A Systematic Review

Air pollution has a negative impact on one's health and on the central nervous system. We decided to assess studies that evaluated the relationship between air pollution and cognitive functions in children and adolescents by reviewing studies that had been published between January 2009 and May 2019. We searched three major databases for original works (26 studies) and for studies using brain imaging methods based on MRI (six studies). Adverse effects of air pollutants on selected cognitive or psychomotor functions were found in all of the studies. Exposure to nitrogen dioxide, for example, was linked to impaired working memory, general cognitive functions, and psychomotor functions; particulate matter 2.5 was linked to difficulties in working memory, short-term memory, attention, processing speed, and fine motor function; black carbon was linked to poor verbal intelligence, nonverbal intelligence, and working memory; airborne copper was linked to impaired attentiveness and fine motor skills; isophorone was linked to lower mathematical skills; and polycyclic aromatic hydrocarbons in fetal life were linked to lower intelligence scores. The studies using MRI showed that high concentrations of air pollutants were linked to changes in the brain's white matter or lower functional integration and segregation in children's brain networks. In view of the global increase in air pollution, there is a need for further research to elucidate the relationship between air pollution and cognitive and motor development in children. According to some studies, neuroinflammation, the e4 allele of the apolipoprotein E gene, and gutathione-S-transferase gene polymorphism processes may play a role.

Assessing Hypoendemic Onchocerciasis in Loa loa Endemic Areas of Southeast Nigeria

Nigeria changed its goal for onchocerciasis from control to transmission elimination. Under the control program, ivermectin mass drug administration (MDA) focused only on hyper/meso-endemic local government areas (LGAs) identified by Rapid Epidemiological Mapping of Onchocerciasis as having ≥ 20% nodule rates. Because transmission is likely in some LGAs where nodule rates are < 20%, the new elimination paradigm requires MDA expansion. Determining which hypoendemic areas require MDA, termed onchocerciasis elimination mapping, is a major challenge. In 2016, we studied 19 ivermectin-naive hypoendemic LGAs in southern Nigeria that bordered LGAs under MDA. Fifty adults and 50 children (aged 5–10 years) were tested in 110 villages for onchocerciasis IgG4 antibody using an Ov16 rapid diagnostic test (RDT). A 10% subset of subjects provided a blood spot for confirmatory Ov16 ELISA. The mean prevalence of RDT positives was 0.5% in the 5,276 children tested (village range, 0.0–4.0%) versus 3.3% in 5,302 adults (village range, 0.0–58.0%). There was 99.3% agreement between the Ov16 RDT and ELISA. Six different MDA launch thresholds were applied to the RDT results based on different recommendations by the Nigeria Onchocerciasis Elimination Committee and the Onchocerciasis Technical Advisory Subgroup of the WHO. Mass drug administration targets for the same area varied tenfold by threshold chosen, from one LGA (population to be treated 221,935) to 13 LGAs (population 2,426,987). Because the Ov16 threshold selected will have considerable cost and resource implications, the decision to initiate MDA should incorporate entomological data demonstrating onchocerciasis transmission.

Neglected tropical diseases and disability-what is the link?

Neglected tropical diseases (NTDs) are a diverse group of infectious conditions that vary in their epidemiology, impact and control. They are among the most common conditions globally, affecting approximately one billion people. Many NTDs have long-term consequences, such as visual and physical impairments. As a result, people with NTDs may have difficulties in carrying out activities or participating in society—in other words, NTDs can cause disabilities. Additionally, NTDs are often strongly linked to stigma and can have mental health consequences. It is therefore important to incorporate rehabilitation within NTD programmes. Rehabilitation can be conceptualized narrowly in terms of the provision of clinical services (e.g. physiotherapy and assistive devices) or, more broadly, including efforts to improve employment, overcome stigma and enhance social participation of people with disabilities. Approximately 15% of the global population has a disability, and this large group must be considered when designing NTD programmes. Improving the inclusion of people with disabilities may require adaptations to NTD programmes, such as making them physically accessible or training staff about disability awareness. Without incorporating disability within NTD programmes, the quality of life of people with NTDs will suffer and global targets for elimination and management of NTDs will not be met.

Genetic evidence for the role of non-human primates as reservoir hosts for human schistosomiasis

Background

Schistosomiasis is a chronic parasitic disease, that affects over 207 million people and causes over 200,000 deaths annually, mainly in sub-Saharan Africa. Although many health measures have been carried out to limit parasite transmission, significant numbers of non-human primates such as Chlorocebus aethiops (Ch. aethiops) (vervet) and Papio anubis (baboon) are infected with S. mansoni, notably in Ethiopia, where they are expected to have potentially significant implications for transmission and control efforts.

Objective

The objective of this study was to assess and compare the genetic diversity and population structure of S. mansoni isolates from human and non-human primates free-ranging in close proximity to villages in selected endemic areas of Ethiopia.

Methods

A cross-sectional study was conducted in three transmission sites: Bochesa, Kime and Fincha. A total of 2,356 S. mansoni miracidia were directly isolated from fecal specimens of 104 hosts (i.e. 60 human hosts and 44 non-human primates). We performed DNA extraction and PCR amplification using fourteen microsatellite loci.

Results

At population scale we showed strong genetic structure between the three sample sites. At the definitive host scale, we observed that host factors can shape the genetic composition of parasite infra-populations. First, in male patients, we observed a positive link between parasite genetic diversity and the age of the patients. Second, we observed a difference in genetic diversity which was high in human males, medium in human females and low in non-human primates (NHPs). Finally, whatever the transmission site no genetic structure was observed between human and non-human primates, however, there appears to be little barriers, if any, host specificity of the S. mansoni populations with cross-host infections.

Conclusion

Occurrence of infection of a single host with multiple S. mansoni strains and inter- and intra-host genetic variations was observed. Substantial genetic diversity and gene flow across the S. mansoni population occurred at each site and non-human primates likely play a role in local transmission and maintenance of infection. Therefore, public health and wildlife professionals should work together to improve disease control and elimination strategies.

Schistosomiasis is a chronic disease caused by flukes (trematodes). The definitive host spectrum of schistosomes, whether human, non-human primates (NHPs) or other mammals, is highly dependent on the schistosome species concerned. Genetic diversity and population structure studies of S. mansoni have provided insights into the variation of natural populations. Understanding S. mansoni genetic diversity and population structure of isolates from human and non-human primate hosts living in close proximity showed the occurrence of infection of a single host with multiple S. mansoni strains and inter- and intra-host genetic variations. In this article, the researchers assert the fact that genetic approach reveals that parasites from the three different sites are independent. Thus, we could consider the three sites as geographical replicates showing the influence of NHPs in parasitic transmission in Ethiopia. This study provides insights into the epidemiology, genetic diversity and population structure of S. mansoni in human and non-human primates in Ethiopia, all of which are crucial for the control of schistosomiasis.

Mapping the burden of onchocercal skin disease

Onchocerciasis is a neglected tropical disease caused by a nematode parasite, Onchocerca volvulus, and transmitted by bites of Simulium blackflies which breed near fast-flowing rivers. In humans, thousands of microfilariae (immature worms) migrate to the skin and eyes where they cause pathology. Historically, much research was devoted to the serious effect of blindness, from which the disease earns its alternative name of 'river blindness'. Mapping the burden of onchocercal skin disease (OSD) was expedited by the development of a clinical classification and grading system that facilitated comparison of data from different countries. After successful field testing in Nigeria, the classification scheme was used in a multicountry study in seven endemic sites, to estimate the true burden of OSD across Africa. High levels of OSD were found, affecting 28% of the population. A new control programme, the African Programme for Onchocerciasis Control (APOC) was launched in 20 countries using annual doses of ivermectin, donated by Merck & Co., Inc. The multicountry study also found a close correlation between the levels of itching and OSD with the level of endemicity, as determined by the prevalence of onchocercal nodules. This enabled APOC to use Rapid Epidemiological Mapping of Onchocerciasis, which entailed identifying likely vector breeding sites near rivers, then sampling 50 adult males in nearby villages to determine the prevalence of nodules and delineate which villages required treatment. Onchocerciasis is now targeted for elimination in Africa, and the challenge is to complete Onchocerciasis Elimination Mapping of hypoendemic areas using serology.

A systematic review and meta-analysis to assess the association between urogenital schistosomiasis and HIV/AIDS infection

Background

Urogenital schistosomiasis and HIV/AIDS infections are widespread in sub-Saharan Africa (SSA) leading to substantial morbidity and mortality. The co-occurrence of both diseases has led to the possible hypothesis that urogenital schistosomiasis leads to increased risk of acquiring HIV infection. However, the available evidence concerning this association is inconsistent. The aim of this study was to systematically review and quantitatively synthesize studies that investigated the association between urogenital schistosomiasis and HIV/AIDS infection.

Methods

A systematic review basing on PRISMA guidelines was conducted. It is registered with PROSPERO, number CRD42018116648. We searched four databases, MEDLINE, EMBASE, Global Health and Global Index Medicus for studies investigating the association between urogenital schistosomiasis and HIV infection. Only studies published in English were considered. Results of the association were summarised by gender. A meta-analysis was performed for studies on females using random-effects model and a pooled OR with 95% confidence interval was reported.

Results

Of the 993 studies screened, only eight observational studies met the inclusion criteria. Across all studies, the reported unadjusted OR ranged from 0.78 to 3.76. The pooled estimate of unadjusted OR among females was 1.31 (95% CI: 0.87–1.99). Only four of the eight studies reported an adjusted OR. A separate meta-analysis done in the three studies among females that reported an adjusted OR showed that the pooled estimate was 1.85 (95% CI: 1.17–2.92). There were insufficient data to pool results for association between urogenital schistosomiasis and HIV infection in the males.

Conclusion

Our investigation supports the hypothesis of an association between urogenital schistosomiasis with HIV/AIDS infection in females. Due to insufficient evidence, no conclusion could be drawn in males with urogenital schistosomiasis. Large-scale prospective studies are needed in future.

Urogenital schistosomiasis, caused by parasitic trematode Schistosoma haematobium is a significant source of morbidity in sub Saharan Africa. HIV infection caused by a retrovirus is of two subtypes HIV 1 and HIV 2, with subtype HIV 1 being found worldwide and more aggressive, leading to HIV/AIDS. Research on both of these diseases in the same settings, has shown that these diseases cross paths. This has led to the suggestion that there could be a possible association between the two. Here we describe a systematic review that was carried out to determine if there is an association between UGS and HIV/AIDS infections. We searched all published articles available in MEDLINE, EMBASE, Global Health (CABI), and Global Index Medicus before 28^th January 2020. We found eight observational studies eligible to be included in the systematic review and no intervention study. Six of these studies were included in the meta-analysis. A summarized meta-analysis of the study findings with adjusted OR showed that there was a likely association between urogenital schistosomiasis and HIV/AIDS infections in females. However, due to limited papers in males, no conclusion could be drawn.

Comprehensive Account on Prevalence and Characteristics of Hydatid Cysts in Livestock from Pakistan

Pakistan is at intersection of hyperendemic regions for hydatidosis. Current study aimed to determine the prevalence of hydatid cysts and cyst characteristics in different intermediate hosts (sheep, goats, cattle and buffaloes) across the 4 provinces of Pakistan. A total of 991 sheep, 1,478 goats, 1,602 cattle and 1,343 buffaloes were examined for presence of hydatid cysts during 2 years (January 2016–December 2018). Differences in frequency of hydatidosis were observed with highest overall prevalence in buffaloes (11.9%) and sheep (11.5%). Highest prevalence and burden of infection were observed in older age animals (23.8%, 9.78±0.49) and females (26.5%, 12.53±0.67). Data for seasonal prevalence alluded to year-round presence of disease with non-significant statistical difference. Organ predilection indicated liver as the most preferred site of cyst localization followed mainly by lungs. An over-dispersion pattern was observed in all infected animals as majority of cysts belonged <10 cysts per infected host category. Highest percentage of fertile cysts was observed in liver of sheep. Interestingly, solitary form of cysts had higher fertility rate than multiple form. Amid lack of data and wide gap of knowledge, this study would try to fill up the lacunae regarding this neglected tropical disease. Extensive rearing of livestock, unregulated official slaughter and home slaughtering have played role in adaptability of E. granulosus in Pakistan.

Genomic analysis of natural intra-specific hybrids among Ethiopian isolates of Leishmania donovani

Parasites of the genus Leishmania (Kinetoplastida: Trypanosomatidae) cause widespread and devastating human diseases. Visceral leishmaniasis due to Leishmania donovani is endemic in Ethiopia where it has also been responsible for major epidemics. The presence of hybrid genotypes has been widely reported in surveys of natural populations, genetic variation reported in a number of Leishmania species, and the extant capacity for genetic exchange demonstrated in laboratory experiments. However, patterns of recombination and the evolutionary history of admixture that produced these hybrid populations remain unclear. Here, we use whole-genome sequence data to investigate Ethiopian L. donovani isolates previously characterized as hybrids by microsatellite and multi-locus sequencing. To date there is only one previous study on a natural population of Leishmania hybrids based on whole-genome sequences. We propose that these hybrids originate from recombination between two different lineages of Ethiopian L. donovani occurring in the same region. Patterns of inheritance are more complex than previously reported with multiple, apparently independent, origins from similar parents that include backcrossing with parental types. Analysis indicates that hybrids are representative of at least three different histories. Furthermore, isolates were highly polysomic at the level of chromosomes with differences between parasites recovered from a recrudescent infection from a previously treated individual. The results demonstrate that recombination is a significant feature of natural populations and contributes to the growing body of data that shows how recombination, and gene flow, shape natural populations of Leishmania.

Partnerships for better neglected disease drug discovery and development: how have we fared?

Introduction: In the field of neglected disease, mushrooming partnerships have changed the landscape in the last decades. With high diversity in participants, type, scope, and operational models, partnership becomes the ultimate choice for drug discovery and development. This paper aims to reflect on this phenomenon based on experiences and lessons learned, providing insights for the future.Areas covered: Lack of safe and effective drugs for neglected diseases stems from market and public policy failure. Combining resources, skills, and expertise justifies working collaboratively in the R&D quest. The advancement of public-private partnerships (PPP), including product development partnership (PDP) for neglected diseases, is described, herein, including the rationale behind their conception, evolution, expansion, and alternative approaches. The author also discusses the appeals and the pitfalls of partnership in this field.Expert opinion: The progressive partnerships in drug discovery and development for neglected diseases need to be encouraged, especially in alignment with an open science culture. Experiences in partnerships vary with bias for successful ones, rendering more rigorous evaluation and research necessary. Eventually, the focus of improving partnership should not only be on addressing discovery bottlenecks, but also safeguarding access and delivery. Expanding focus to include vaccines and diagnostics is necessary.

Integrated community-based intervention for urinary schistosomiasis and soil-transmitted helminthiasis in children from Caxito, Angola

BACKGROUND

Schistosomiasis and soil-transmitted helminths (STH) infections are major public health problems. We aimed to study the 6-mo impact of mass drug administration with praziquantel and albendazole on urinary schistosomiasis and STH.

METHODS

We examined children (aged 2-15 y) from one hamlet, who provided urine and faeces samples at baseline (n=197), 1 mo (n=102) and 6 mo (n=92); 67 completed the protocol.

RESULTS

At baseline, 47/67 (70.1%) children presented Schistosoma haematobium (75.8% in the baseline total sample) and 12/67 (17.9%) with STH (30.5% in the initial sample, p=0.010). Among the children, 47.3% had heavy Schistosoma haematobium infection. The most frequent STH was Trichuris trichiura in 9.0%. We also found Hymenolepis nana (13.2%) and Plasmodium falciparum (9.1%) infections and anaemia (82.1%). One mo after chemotherapy there was a significant (p=0.013) reduction of Schistosoma haematobium prevalence (23.5%) and a high egg reduction rate (86.9%). Considering the sample of 67 children, the mean egg concentration was 498 at baseline, 65 at 1 mo and 252 at 6 mo (p<0.05). We also observed a reduction in STH infections, 50% in Ascaris lumbricoides, 33.3% in T. trichiura and 50% in hookworms. At 6 mo, the prevalence of Schistosoma haematobium (76.1%) was similar to the baseline and the STH reduction was not significant.

CONCLUSIONS

Longitudinal studies have reported many losses in these settings, but we were able to show that mass drug administration for control of schistosomiasis and STH present low effectiveness, that reinfections occur rapidly and that stand alone anthelmintic therapy is not a sustainable choice.

Are low and middle-income countries prioritising high-value healthcare interventions?

Introduction

Since resources are finite, investing in services that produce the highest health gain 'return on investment' is critical. We assessed the extent to which low and middle-income countries (LMIC) have included cost-saving interventions in their national strategic health plans.

Methods

We used the Tufts Medical Center Global Health Cost-Effectiveness Analysis Registry, an open-source database of English-language cost-per-disability-adjusted life year (DALY) studies, to identify analyses published in the last 10 years (2008-2017) of cost-saving health interventions in LMICs. To assess whether countries prioritised cost-saving interventions within their latest national health strategic plans, we identified 10 countries, all in sub-Saharan Africa, with the highest measures on the global burden of disease scale and reviewed their national health priority plans.

Results

We identified 392 studies (63%) targeting LMICs that reported 3315 cost-per-DALY ratios, of which 207 ratios (6%) represented interventions reported to be cost saving. Over half (53%) of these targeted sub-Saharan Africa. For the 10 countries we investigated in sub-Saharan Africa, 58% (79/137) of cost-saving interventions correspond with priorities identified in country plans. Alignment ranged from 95% (21/22 prioritised cost-saving ratios) in South Africa to 17% (2/12 prioritised cost-saving ratios) in Cameroon. Human papillomavirus vaccination was a noted priority in 70% (7/10) of national health prioritisation plans, while 40% (4/10) of countries explicitly included prenatal serological screening for syphilis. HIV prevention and treatment were stated priorities in most country health plans, whereas 40% (2/5) of countries principally outlined efforts for lymphatic filariasis. From our sample of 45 unique interventions, 36% of interventions (16/45) included costs associated directly with the implementation of the intervention.

Conclusion

Our findings indicate substantial variation across country and disease area in incorporating economic evidence into national health priority plans in a sample of sub-Saharan African countries. To make health economic data more salient, the authors of cost-effectiveness analyses must do more to reflect implementation costs and other factors that could limit healthcare delivery.

Schistosomiasis, strongyloidiasis and Chagas disease: the leading imported neglected tropical diseases in Italy

BACKGROUND

In recent years, an increasing number of individuals affected by neglected tropical diseases (NTDs) have been observed in Italy, due to migration, international travels and climate changes. Reliable data on the current NTD epidemiology in Italy and the health system preparedness on this issue are not available.

METHODS

We report the results of a survey on selected NTDs (schistosomiasis, strongyloidiasis, echinococcosis, Chagas disease, leishmaniasis, cysticercosis, filariasis and scabies) in nine Italian sentinel centres, in order to investigate their occurrence throughout the country and identify which ones are a priority for public health interventions, development of protocols for case management, and training activities. To explore the preparedness of the centres, we investigate the availability of specific diagnostic tools and drugs, needed for the management of the most common NTDs. We also reviewed and summarized the available national policies, recommendations and guidelines on NTDs in Italy.

RESULTS

Overall, 4123 NTDs cases were diagnosed in nine Italian centres within a 7-year period (2011-2017). Schistosomiasis and strongyloidiasis were the most common NTDs, accounting for about one-third each of all the diagnosed cases, followed by Chagas disease. The number of cases showed a significant trend to increase over time, mainly due to foreign-born subjects. Serology for Schistosoma spp. and Strongyloides stercoralis was available in seven and five centres, respectively. Agar plate stool culture for S. stercoralis was available in three sites. Ivermectin and praziquantel were always available in six centres. Six national policies, recommendations and guidelines documents were available, but for the most part, they are not fully implemented yet.

CONCLUSIONS

This survey showed how some NTDs, such as schistosomiasis and strongyloidiasis, are becoming more common in Italy, due to multiple components. A list of seven key actions was proposed, in order to improve diagnosis, management and control of NTDs in Italy.

Testing the Infection Prevalence of Schistosoma mansoni after Mass Drug Administration by Comparing Sensitivity and Specificity of Species-Specific Repeat Fragment Amplification by PCR and Loop-Mediated Isothermal Amplification

Schistosomiasis is a blood parasitic disease caused by trematode parasites of the genus Schistosoma. Schistosoma mansoni is one of the main contributors of the disease and 90% of the global burden of schistosomiasis is in Africa. Mass drug administration (MDA) has been implemented to reduce the disease burden in endemic areas. Because of MDA, the diagnostic sensitivity and specificity for classical diagnostic tests are reduced. In any disease situation, diagnosis is vital in determining asymptomatic, concurrent, current, new, and reinfection cases to evaluate the efficacy of any control program. We have evaluated the positive infection for S. mansoni from filtered urine samples collected from Zambian school children after MDA using loop-mediated isothermal amplification (LAMP) and compared its sensitivity and specificity with polymerase chain reaction (PCR). One hundred eleven urine samples collected from school children aged between 7 and 15 years from Siavonga district in southern Zambia were evaluated by PCR and LAMP for DNA extracted by two different protocols (filter-based versus crude extraction). The infection prevalence was 77% with PCR and almost 94% with mansoni-LAMP. Also, LAMP detected 16% (Qiagen extraction) and 10% (LAMP-Procedure for Ultra Rapid Extraction) more positive S. mansoni infection than PCR. We have demonstrated the efficacy of LAMP in a laboratory setup after MDA. The possible inclusion of LAMP as a field-based point-of-care test for surveillance can provide reliable prevalence of schistosomiasis after MDA and help in determining the efficacy of a control program.