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1.
Parasitol Res ; 123(6): 256, 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38935203

ABSTRACT

Cutaneous leishmaniasis (CL), a neglected tropical disease, is a major public health concern in Yemen, with Leishmania tropica identified as the main causative agent. This study aims to investigate the occurrence and distribution of Leishmania parasites in domestic and wild animals in CL endemic areas in the western highlands of Yemen. A cross-sectional study was conducted in the Utmah District of western Yemen. Blood and skin scraping specimens were collected from 122 domestic and wild animals and tested for the Leishmania DNA using internal transcribed spacer 1 (ITS1) nested polymerase chain reaction. Phylogenetic analyses were performed on 20 L. tropica sequences obtained from animals in this study and 34 sequences from human isolates (collected concurrently from the same study area) retrieved from the GenBank. Overall, L. tropica was detected in 16.4% (20/122) of the examined animals, including 11 goats, two dogs, two bulls, one cow, one donkey, one rabbit, one rat and one bat. None of the examined cats and sheep was positive. The animal sequences were segregated into four different L. tropica haplotypes, with the majority of the animal (15/20) and human (32/34) sequences composed of one dominant haplotype/genotype. These findings represent the first confirmed evidence of natural L. tropica infections in different kinds of domestic and wild animals in western Yemen, suggesting these animals potentially have a role in the transmission of CL in Yemen. Therefore, a One Health approach is required for the effective prevention and control of this devastating disease among endemic populations.


Subject(s)
Animals, Domestic , Animals, Wild , Leishmania tropica , Leishmaniasis, Cutaneous , One Health , Phylogeny , Animals , Leishmania tropica/genetics , Leishmania tropica/isolation & purification , Leishmania tropica/classification , Leishmaniasis, Cutaneous/epidemiology , Leishmaniasis, Cutaneous/veterinary , Leishmaniasis, Cutaneous/parasitology , Yemen/epidemiology , Humans , Cross-Sectional Studies , Animals, Wild/parasitology , Animals, Domestic/parasitology , DNA, Protozoan/genetics , Neglected Diseases/parasitology , Neglected Diseases/epidemiology , Neglected Diseases/veterinary , Endemic Diseases/veterinary , DNA, Ribosomal Spacer/genetics , Polymerase Chain Reaction/veterinary , Sequence Analysis, DNA , Male
2.
Methods Cell Biol ; 188: 205-236, 2024.
Article in English | MEDLINE | ID: mdl-38880525

ABSTRACT

African trypanosomiases and leishmaniases are significant neglected tropical diseases (NTDs) that affect millions globally, with severe health and socio-economic consequences, especially in endemic regions. Understanding the pathogenesis and dissemination of Trypanosoma brucei and Leishmania spp. parasites within their hosts is pivotal for the development of effective interventions. Whole-body bioluminescence and fluorescence imaging systems (BLI and FLI, respectively), are powerful tools to visualize and quantify the progression and distribution of these parasites in real-time within live animal models. By combining this technology with the engineering of stable T. brucei and Leishmania spp. strains expressing luciferase and/or fluorescent proteins, crucial aspects of the infection process including the parasites' homing, the infection dynamics, the tissue tropism, or the efficacy of experimental treatments and vaccines can be deeply investigated. This methodology allows for enhanced sensitivity and resolution, elucidating previously unrecognized infection niches and dynamics. Importantly, whole-body in vivo imaging is non-invasive, enabling for longitudinal studies during the course of an infection in the same animal, thereby aligning with the "3Rs" principle of animal research. Here, we detail a protocol for the generation of dual-reporter T. brucei and L. major, and their use to infect mice and follow the spatiotemporal dynamics of infection by in vivo imaging systems. Additionally, 3D micro-computed tomography (µCT) coupled to BLI in T. brucei-infected animals is applied to gain insights into the anatomical parasite distribution. This Chapter underscores the potential of these bioimaging modalities as indispensable tools in parasitology, paving the way for novel therapeutic strategies and deeper insights into host-parasite interactions.


Subject(s)
Disease Models, Animal , Trypanosoma brucei brucei , Animals , Mice , Trypanosoma brucei brucei/pathogenicity , Multimodal Imaging/methods , Neglected Diseases/parasitology , Neglected Diseases/diagnostic imaging , Trypanosomiasis, African/parasitology , Trypanosomiasis, African/diagnostic imaging , Luminescent Measurements/methods
3.
Pan Afr Med J ; 47: 142, 2024.
Article in English | MEDLINE | ID: mdl-38933431

ABSTRACT

Lymphatic filariasis is a neglected tropical disease that affects the lymphatic system of humans. The major etiologic agent is a nematode called Wuchereria bancrofti, but Brugia malayi and Brugia timoriare sometimes encountered as causative agents. Mosquitoes are the vectors while humans the definitive hosts respectively. The burden of the disease is heavier in Nigeria than in other endemic countries in Africa. This occurs with increasing morbidity and mortality at different locations within the country, the World Health Organization recommended treatments for lymphatic filariasis include the use of Albendazole (400mg) twice per year in co-endemic areas with loa loa, Ivermectin (200mcg/kg) in combination with Albendazole (400mg) in areas that are co-endemic with onchocerciasis, ivermectin (200mcg/kg) with diethylcarbamazine citrate (DEC) (6mg/kg) and albendazole (400mg) in areas without onchocerciasis. This paper covered a systematic review, meta-analysis, and scoping review on lymphatic filariasis in the respective geopolitical zones within the country. The literature used was obtained through online search engines including PubMed and Google Scholar with the heading "lymphatic filariasis in the name of the state", Nigeria. This review revealed an overall prevalence of 11.18% with regional spread of Northwest (1.59%), North Central and North East, (4.52%), South West (1.26%), and South-South with South East (3.81%) prevalence. The disease has been successfully eliminated in Argungu local government areas (LGAs) of Kebbi State, Plateau, and Nasarawa States respectively. Most clinical manifestations (31.12%) include hydrocele, lymphedema, elephantiasis, hernia, and dermatitis. Night blood samples are appropriate for microfilaria investigation. Sustained MDAs, the right testing methods, early treatment of infected cases, and vector control are useful for the elimination of lymphatic filariasis for morbidity management and disability prevention in the country. Regional control strategies, improved quality monitoring of surveys and intervention programs with proper records of morbidity and disability requiring intervention are important approaches for the timely elimination of the disease in Nigeria.


Subject(s)
Elephantiasis, Filarial , Wuchereria bancrofti , Elephantiasis, Filarial/epidemiology , Elephantiasis, Filarial/drug therapy , Humans , Nigeria/epidemiology , Animals , Wuchereria bancrofti/isolation & purification , Filaricides/administration & dosage , Filaricides/therapeutic use , Albendazole/administration & dosage , Neglected Diseases/epidemiology , Neglected Diseases/parasitology , Ivermectin/administration & dosage , Ivermectin/therapeutic use , Brugia malayi/isolation & purification
4.
PLoS One ; 19(5): e0302554, 2024.
Article in English | MEDLINE | ID: mdl-38696499

ABSTRACT

BACKGROUND: Female genital schistosomiasis (FGS) is a gynaecological complication of urinary schistosomiasis (US) with an estimated burden of 20-120 million cases in endemic areas. A neglected sexual and reproductive health disease in sub-Saharan Africa, FGS increases susceptibility to sexually transmitted infections including cervical cancer and infertility among other morbidities. However, there appears to be limited FGS knowledge among practicing and pre-service health providers with implications for control. We assessed FGS awareness among final-year midwifery students who would soon be delivering primary maternal and reproductive health care. METHODS: A cross-sectional study was conducted among 193 randomly selected final-year students from all three midwifery training institutions in the Volta region of Ghana in August/September, 2022. Data on participants' demographics and knowledge of the transmission, signs and symptoms, complications, treatment and prevention of both FGS and US were collected using structured questionnaires. Summary statistics were presented as frequencies, proportions and percentages. RESULTS: Only 23.3% (44/189) of participants had heard about FGS compared to 64% (123/192) for US. Of the former, 42 (95%), 40 (91%) and 36 (81.8%) respectively identified genital itching/burning sensation, bloody vaginal discharge and pelvic pain/pain during intercourse as part of the symptoms of FGS. Less than a third (13/44) and about half (25/44) of those who indicated hearing about FGS knew it can be a risk for ectopic pregnancies and infertility respectively. Majority of these participants, 40 (91%), wrongly selected antibiotics as treatment for FGS while 9 indicated it is prevented by sleeping in insecticide-treated nets. CONCLUSION: Awareness of FGS was limited among the study participants. The high prevalence of knowledge of some FGS symptoms related to the genitalia needs cautious interpretation. Health care training institutions must make deliberate efforts to highlight FGS in the training of midwives as the condition has diagnostic and management implications for some sexual and reproductive health conditions.


Subject(s)
Clinical Competence , Genital Diseases, Female , Midwifery , Neglected Diseases , Schistosomiasis haematobia , Students, Nursing , Genital Diseases, Female/diagnosis , Genital Diseases, Female/parasitology , Schistosomiasis haematobia/complications , Schistosomiasis haematobia/diagnosis , Female , Ghana , Cross-Sectional Studies , Neglected Diseases/diagnosis , Neglected Diseases/parasitology , Adolescent , Young Adult , Adult
5.
Expert Opin Investig Drugs ; 33(6): 575-590, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38686546

ABSTRACT

INTRODUCTION: Chagas disease is spreading faster than expected in different countries, and little progress has been reported in the discovery of new drugs to combat Trypanosoma cruzi infection in humans. Recent clinical trials have ended with small hope. The pathophysiology of this neglected disease and the genetic diversity of parasites are exceptionally complex. The only two drugs available to treat patients are far from being safe, and their efficacy in the chronic phase is still unsatisfactory. AREAS COVERED: This review offers a comprehensive examination and critical review of data reported in the last 10 years, and it is focused on findings of clinical trials and data acquired in vivo in preclinical studies. EXPERT OPINION: The in vivo investigations classically in mice and dog models are also challenging and time-consuming to attest cure for infection. Poorly standardized protocols, availability of diagnosis methods and disease progression markers, the use of different T. cruzi strains with variable benznidazole sensitivities, and animals in different acute and chronic phases of infection contribute to it. More synchronized efforts between research groups in this field are required to put in evidence new promising substances, drug combinations, repurposing strategies, and new pharmaceutical formulations to impact the therapy.


Subject(s)
Chagas Disease , Disease Models, Animal , Drug Development , Trypanocidal Agents , Trypanosoma cruzi , Chagas Disease/drug therapy , Chagas Disease/parasitology , Humans , Animals , Trypanosoma cruzi/drug effects , Trypanocidal Agents/pharmacology , Mice , Dogs , Nitroimidazoles/pharmacology , Nitroimidazoles/administration & dosage , Neglected Diseases/drug therapy , Neglected Diseases/parasitology , Drug Evaluation, Preclinical
6.
Curr Top Med Chem ; 24(2): 89-108, 2024.
Article in English | MEDLINE | ID: mdl-37842892

ABSTRACT

Recent developments in the use of natural product-based molecules as antiparasitic agents for Malaria, leishmaniasis (LE), Chagas disease (CD), and Human African trypanosomiasis (HAT) are reviewed. The role of diverse plants in developing bioactive species is discussed in addition to analyzing the structural diversity of natural products as active agents and the diverse biological applications in CD, HAT, LE, and Malaria. This review focuses on medicinal chemistry, emphasizing the structural characteristics of natural molecules as bioactive agents against parasitic infections caused by Leishmania, Trypanosoma, and Plasmodium parasites.


Subject(s)
Antiprotozoal Agents , Biological Products , Chagas Disease , Leishmaniasis , Malaria , Trypanosomiasis, African , Animals , Humans , Antiparasitic Agents/pharmacology , Antiparasitic Agents/therapeutic use , Antiparasitic Agents/chemistry , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Antiprotozoal Agents/chemistry , Biological Products/pharmacology , Biological Products/therapeutic use , Biological Products/chemistry , Neglected Diseases/drug therapy , Neglected Diseases/parasitology , Trypanosomiasis, African/drug therapy , Leishmaniasis/drug therapy , Chagas Disease/drug therapy , Malaria/drug therapy
7.
Infect Dis Poverty ; 12(1): 32, 2023 Apr 10.
Article in English | MEDLINE | ID: mdl-37038199

ABSTRACT

BACKGROUND: Neglected tropical diseases affect the most vulnerable populations and cause chronic and debilitating disorders. Socioeconomic vulnerability is a well-known and important determinant of neglected tropical diseases. For example, poverty and sanitation could influence parasite transmission. Nevertheless, the quantitative impact of socioeconomic conditions on disease transmission risk remains poorly explored. METHODS: This study investigated the role of socioeconomic variables in the predictive capacity of risk models of neglected tropical zoonoses using a decade of epidemiological data (2007-2018) from Brazil. Vector-borne diseases investigated in this study included dengue, malaria, Chagas disease, leishmaniasis, and Brazilian spotted fever, while directly-transmitted zoonotic diseases included schistosomiasis, leptospirosis, and hantaviruses. Environmental and socioeconomic predictors were combined with infectious disease data to build environmental and socioenvironmental sets of ecological niche models and their performances were compared. RESULTS: Socioeconomic variables were found to be as important as environmental variables in influencing the estimated likelihood of disease transmission across large spatial scales. The combination of socioeconomic and environmental variables improved overall model accuracy (or predictive power) by 10% on average (P < 0.01), reaching a maximum of 18% in the case of dengue fever. Gross domestic product was the most important socioeconomic variable (37% relative variable importance, all individual models exhibited P < 0.00), showing a decreasing relationship with disease indicating poverty as a major factor for disease transmission. Loss of natural vegetation cover between 2008 and 2018 was the most important environmental variable (42% relative variable importance, P < 0.05) among environmental models, exhibiting a decreasing relationship with disease probability, showing that these diseases are especially prevalent in areas where natural ecosystem destruction is on its initial stages and lower when ecosystem destruction is on more advanced stages. CONCLUSIONS: Destruction of natural ecosystems coupled with low income explain macro-scale neglected tropical and zoonotic disease probability in Brazil. Addition of socioeconomic variables improves transmission risk forecasts on tandem with environmental variables. Our results highlight that to efficiently address neglected tropical diseases, public health strategies must target both reduction of poverty and cessation of destruction of natural forests and savannas.


Subject(s)
Chagas Disease , Communicable Diseases , Animals , Humans , Ecosystem , Poverty , Zoonoses/epidemiology , Neglected Diseases/epidemiology , Neglected Diseases/parasitology
8.
Parasit Vectors ; 15(1): 34, 2022 Jan 24.
Article in English | MEDLINE | ID: mdl-35073980

ABSTRACT

Sensitive, reliable and fast diagnostic tools that are applicable in low-resource settings, at the point of care (PoC), are seen as crucial in the fight against visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL). Addressing the need for a PoC test, several diagnostic tests, including serological and molecular methods, have been developed and evaluated in the past. One promising molecular method, already implemented for diagnosis of a range of diseases, is the loop-mediated isothermal amplification (LAMP) protocol. In this systematic review and meta-analysis, using a comprehensive search strategy, we focus on studies evaluating the performance of LAMP for the diagnosis of leishmaniasis in humans and other mammals such as dogs, compared with microscopy and/or any other molecular diagnostic method. A meta-analysis, pooling sensitivity and specificity rates and calculating areas under the curve (AUCs) in summary receiver operating characteristic (SROC) plots, was conducted on datasets extracted from studies, grouped by clinical condition and sample type. We found high sensitivity and specificity for LAMP when compared with microscopy and PCR using blood samples, with pooled estimate values of > 90% for all subgroups, corresponding to calculated AUC values > 0.96, except for LAMP compared to microscopy for diagnosis of CL. However, only a limited number of studies were truly comparable. Most of the observed heterogeneity is likely based on true differences between the studies rather than sampling error only. Due to simple readout methods and low laboratory equipment requirements for sample preparation compared to other molecular methods, LAMP is a promising candidate for a molecular (near-)PoC diagnostic method for VL and CL.


Subject(s)
Leishmaniasis, Visceral/diagnosis , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , Pathology, Molecular/methods , Animals , Dogs , Genes, Protozoan , Humans , Leishmania/genetics , Neglected Diseases/diagnosis , Neglected Diseases/parasitology
9.
PLoS Negl Trop Dis ; 16(1): e0010109, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35030166

ABSTRACT

BACKGROUND: Neurocysticercosis (NCC), and cystic echinococcosis (CE) are two neglected diseases caused by cestodes, co-endemic in many areas of the world. Imaging studies and serological tests are used in the diagnosis of both parasitic diseases, but cross-reactions may confound the results of the latter. The novel multiplex bead-based assay with recombinant antigens has been reported to increases the diagnostic accuracy of serological techniques. METHODOLOGY: We set-up an immunoassay based on the multiplex bead-based platform (MBA), using the rT24H (against Cysticercus cellulosae, causing cysticercosis) and r2B2t (against Echinococcus granulosus sensu lato, causing CE) recombinant antigens, for simultaneous and differential diagnosis of these infections. The antigens were tested on 356 sera from 151 patients with CE, 126 patients with NCC, and 79 individuals negative for both diseases. Specificity was calculated including sera from healthy donors, other neurological diseases and the respective NCC or CE sera counterpart. The diagnostic accuracy of this assay was compared with two commercial ELISA tests, Novalisa and Ridascreen, widely used in the routine diagnosis of cysticercosis and CE, respectively. MAIN FINDINGS: For the diagnosis of NCC, sensitivity ranged from 57.94-63.49% for the rT24H-MBA, and 40.48-46.03% for Novalisa ELISA depending on exclusion or inclusion of sera having equivocal results on ELISA from the analysis; specificities ranged from 90.87-91.30% and 70.43-76.96%, respectively. AUC values of the ROC curve were 0.783 (rT24H) and 0.619 (Novalisa) (p-value < 0.001). For the diagnosis of CE, the sensitivity of the r2B2t-MBA ranged from 68.87-69.77% and of Ridascreen ELISA from 50.00-57.62%; specificities from 92.47-92.68% and from 74.15-80.98%, respectively. AUC values were 0.717 and 0.760, respectively. CONCLUSIONS/SIGNIFICANCE: Overall, the recombinant antigens tested with the bead-based technology showed better diagnostic accuracy than the commercial assays, particularly for the diagnosis of NCC. The possibility of testing the same serum sample simultaneously for the presence of antibodies against both antigens is an added value particularly in seroprevalence studies for cysticercosis linked to control programs in endemic areas where these two parasites coexist.


Subject(s)
Antibodies, Helminth/blood , Echinococcosis/diagnosis , Echinococcus granulosus/immunology , Neurocysticercosis/diagnosis , Taenia solium/immunology , Animals , Antigens, Helminth/genetics , Antigens, Helminth/immunology , Echinococcosis/parasitology , Enzyme-Linked Immunosorbent Assay/methods , Humans , Neglected Diseases/diagnosis , Neglected Diseases/parasitology , Neurocysticercosis/parasitology , Recombinant Proteins/genetics , Recombinant Proteins/immunology , Sensitivity and Specificity , Serologic Tests
10.
Cytokine ; 149: 155701, 2022 01.
Article in English | MEDLINE | ID: mdl-34741881

ABSTRACT

The severity of chronic schistosomiasis has been mainly associated with the intensity and extension of the inflammatory response induced by egg-secreted antigens in the host tissue, especially in the liver and intestine. During acute schistosomiasis, eosinophils account for approximately 50% of the cells that compose the liver granulomas; however, the role of this cell-type in the pathology of schistosomiasis remains controversial. In the current study, we compared the parasite burden and liver immunopathological changes during experimental schistosomiasis in wild-type (WT) BALB/c mice and BALB/c mice selectively deficient for the differentiation of eosinophils (ΔdblGATA). Our data demonstrated that the absence of eosinophil differentiation did not alter the S. mansoni load or the liver retention of parasite eggs; however, there were significant changes in the liver immune response profile and tissue damage. S. mansoni infection in ΔdblGATA mice resulted in significantly lower liver concentrations of IL-5, IL-13, IL-33, IL-17, IL-10, and TGF-ß and higher concentrations of IFN-γ and TNF-α, as compared to WT mice. The changes in liver immune response observed in infected ΔdblGATA mice were accompanied by lower collagen deposition, but higher liver damage and larger granulomas. Moreover, the absence of eosinophils resulted in a higher mortality rate in mice infected with a high parasite load. Therefore, the data indicated that eosinophils participate in the establishment and/or amplification of liver Th-2 and regulatory response induced by S. mansoni, which is necessary for the balance between liver damage and fibrosis, which in turn is essential for modulating disease severity.


Subject(s)
Eosinophils/immunology , Immunity/immunology , Liver Diseases/immunology , Liver/immunology , Neglected Diseases/immunology , Schistosomiasis mansoni/immunology , Animals , Cytokines/immunology , Disease Models, Animal , Eosinophils/parasitology , Female , Fibrosis/immunology , Fibrosis/parasitology , Granuloma/immunology , Granuloma/parasitology , Intestines/immunology , Intestines/parasitology , Liver/parasitology , Liver Diseases/parasitology , Mice , Mice, Inbred BALB C , Neglected Diseases/parasitology
11.
Arch Pharm (Weinheim) ; 355(2): e2100338, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34661935

ABSTRACT

Neglected tropical diseases are a diverse group of communicable diseases that are endemic in low- or low-to-middle-income countries located in tropical and subtropical zones. The number and availability of drugs for treating these diseases are low, the administration route is inconvenient in some cases, and most of them have safety, efficacy, or adverse/toxic reaction issues. The need for developing new drugs to deal with these issues is clear, but one of the most drastic consequences of this negligence is the lack of interest in the research and development of new therapeutic options among major pharmaceutical companies. Positive changes have been achieved over the last few years, although the overall situation remains alarming. After more than one decade since the original work reviewing antiprotozoal agents came to light, now it is time to question ourselves: How has the scenario for the treatment of protozoal diseases such as malaria, leishmaniasis, human African trypanosomiasis, and American trypanosomiasis changed? This review covers the last decade in terms of the drugs currently available for the treatment of these diseases as well as the clinical candidates being currently investigated.


Subject(s)
Antiprotozoal Agents/pharmacology , Neglected Diseases/drug therapy , Protozoan Infections/drug therapy , Animals , Drug Development/trends , Humans , Neglected Diseases/parasitology , Protozoan Infections/parasitology
13.
Malar J ; 20(1): 482, 2021 Dec 23.
Article in English | MEDLINE | ID: mdl-34949205

ABSTRACT

BACKGROUND: Information on the foci of Plasmodium species infections is essential for any country heading towards elimination. Odisha, one of the malaria-endemic states of India is targeting elimination of malaria by 2030. To support decision-making regarding targeted intervention, the distribution of Plasmodium species infections was investigated in hard-to-reach areas where a special malaria elimination drive, namely Durgama Anchalare Malaria Nirakaran (DAMaN) began in 2017. METHODS: A cross-sectional survey was conducted in 2228 households during July to November 2019 in six districts, to evaluate the occurrence of Plasmodium species. The species were identified by polymerase chain reaction (PCR) followed by sequencing, in case of Plasmodium ovale. RESULTS: Of the 3557 blood specimens tested, malaria infection was detected in 282 (7.8%) specimens by PCR. Of the total positive samples, 14.1% were P. ovale spp. and 10.3% were Plasmodium malariae infections. The majority of P. ovale spp. (75.8%) infections were mixed with either Plasmodium falciparum and/or Plasmodium vivax and found to be distributed in three geophysical regions (Northern-plateau, Central Tableland and Eastern Ghat) of the State, while P. malariae has been found in Northern-plateau and Eastern Ghat regions. Speciation revealed occurrence of both Plasmodium ovale curtisi (classic type) and Plasmodium ovale wallikeri (variant type). CONCLUSIONS: In the present study a considerable number of P. ovale spp. and P. malariae were detected in a wide geographical areas of Odisha State, which contributes around 40% of the country's total malaria burden. For successful elimination of malaria within the framework of national programme, P. ovale spp. along with P. malariae needs to be incorporated in surveillance system, especially when P. falciparum and P. vivax spp. are in rapid decline.


Subject(s)
Disease Eradication/statistics & numerical data , Malaria/epidemiology , Neglected Diseases/epidemiology , Plasmodium malariae/isolation & purification , Plasmodium ovale/isolation & purification , Humans , India/epidemiology , Malaria/parasitology , Neglected Diseases/parasitology , Prevalence
14.
Exp Parasitol ; 231: 108171, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34736899

ABSTRACT

Schistosomiasis is a prevalent zoonotic parasitic disease caused by schistosomes. Its main threat to human health is hepatic granuloma and fibrosis due to worm eggs. Praziquantel remains the first choice for the treatment of schistosomiasis but has limited benefit in treating liver fibrosis. Therefore, the need to develop effective drugs for treating schistosomiasis-induced hepatic fibrosis is urgent. High-mobility group box 1 protein (HMGB1) is a potential immune mediator that is highly associated with the development of some fibrotic diseases and may be involved in the liver pathology of schistosomiasis. We speculated that HMGB1 inhibitors could have an anti-fibrotic effect. Sodium butyrate (SB), a potent inhibitor of HMGB1, has shown anti-inflammatory activity in some animal disease models. In this study, we evaluated the effects of SB on a murine schistosomiasis model. Mice were percutaneously infected with 20 ± 2 cercariae of Schistosoma japonicum. SB (500 mg/kg/day) was administered every 3 days for the entire experiment period. The activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), liver histopathology, HMGB1 expression, and the levels of interferon gamma (IFN-γ), transforming growth factor-ß1 (TGF-ß1), and interleukin-6 (IL-6) in serum were analyzed. SB reduced hepatic granuloma and fibrosis of schistosomiasis, reflected by the decreased levels of ALT and AST in serum and the reduced expression of pro-inflammatory and fibrogenic cytokines (IFN-γ, TGF-ß1, and IL-6). The protective effect could be attributable to the inhibition of the expression of HMGB1 and release by SB.


Subject(s)
Butyric Acid/pharmacology , Butyric Acid/therapeutic use , HMGB1 Protein/antagonists & inhibitors , Liver Cirrhosis/drug therapy , Schistosoma japonicum/drug effects , Schistosomiasis japonica/drug therapy , Alanine Transaminase/analysis , Animals , Aspartate Aminotransferases/analysis , Blotting, Western , Cytokines/blood , Disease Models, Animal , Down-Regulation , Enzyme-Linked Immunosorbent Assay , Female , HMGB1 Protein/genetics , Histamine Antagonists/pharmacology , Histamine Antagonists/therapeutic use , Humans , Liver/enzymology , Liver/metabolism , Liver/parasitology , Liver Cirrhosis/parasitology , Mice , Mice, Inbred C57BL , Neglected Diseases/drug therapy , Neglected Diseases/parasitology , Real-Time Polymerase Chain Reaction , Schistosomiasis japonica/complications , Schistosomiasis japonica/immunology , Specific Pathogen-Free Organisms , Zoonoses/parasitology
15.
Proc Natl Acad Sci U S A ; 118(41)2021 10 12.
Article in English | MEDLINE | ID: mdl-34615712

ABSTRACT

Zoonotic spillover and hybridization of parasites are major emerging public and veterinary health concerns at the interface of infectious disease biology, evolution, and control. Schistosomiasis is a neglected tropical disease of global importance caused by parasites of the Schistosoma genus, and the Schistosoma spp. system within Africa represents a key example of a system where spillover of animal parasites into human populations has enabled formation of hybrids. Combining model-based approaches and analyses of parasitological, molecular, and epidemiological data from northern Senegal, a region with a high prevalence of schistosome hybrids, we aimed to unravel the transmission dynamics of this complex multihost, multiparasite system. Using Bayesian methods and by estimating the basic reproduction number (R0 ), we evaluate the frequency of zoonotic spillover of Schistosoma bovis from livestock and the potential for onward transmission of hybrid S. bovis × S. haematobium offspring within human populations. We estimate R0 of hybrid schistosomes to be greater than the critical threshold of one (1.76; 95% CI 1.59 to 1.99), demonstrating the potential for hybridization to facilitate spread and establishment of schistosomiasis beyond its original geographical boundaries. We estimate R0 for S. bovis to be greater than one in cattle (1.43; 95% CI 1.24 to 1.85) but not in other ruminants, confirming cattle as the primary zoonotic reservoir. Through longitudinal simulations, we also show that where S. bovis and S. haematobium are coendemic (in livestock and humans respectively), the relative importance of zoonotic transmission is predicted to increase as the disease in humans nears elimination.


Subject(s)
Basic Reproduction Number/statistics & numerical data , Livestock/parasitology , Schistosoma haematobium/pathogenicity , Schistosomiasis haematobia/transmission , Schistosomiasis haematobia/veterinary , Animals , Cattle/parasitology , Goats/parasitology , Humans , Neglected Diseases/parasitology , Senegal/epidemiology , Sheep/parasitology , Zoonoses/parasitology , Zoonoses/transmission
16.
PLoS Negl Trop Dis ; 15(7): e0009531, 2021 07.
Article in English | MEDLINE | ID: mdl-34292942

ABSTRACT

The leishmanin skin test (LST) has been used for decades to detect exposure and immunity to the parasite Leishmania, the causative agent of the neglected tropical disease leishmaniasis. In the LST, Leishmania antigen (leishmanin) is intradermally injected into the forearm. In an individual who has been previously infected, a delayed-type hypersensitivity (DTH) reaction results in a measurable induration at the site of the injection, indicating that previous exposure to Leishmania has resulted in the development of cell-mediated immunity. LST positivity is associated with long-lasting protective immunity against reinfection, most notably as reported for visceral leishmaniasis (VL). Despite efforts over the past few decades, leishmanin antigen is no longer produced under good manufacturing practice (GMP) conditions anywhere in the world. Consequently, the use of the LST in epidemiological studies has declined in favor of serological and molecular tests. In this review, we provide a historical overview of the LST and justification for the reintroduction of leishmanin. A GMP-grade leishmanin can be used to detect immunity in vivo by the LST and can be investigated for use in an interferon-γ release assay (IGRA), which may serve as an in vitro version of the LST. The LST will be a valuable tool for surveillance and epidemiological studies in support of the VL elimination programs and as a surrogate marker of immunity in vaccine clinical trials. METHODS: A review of the literature was conducted using PubMed as the primary database, with MeSH terms "leishmanin skin test" OR "Montenegro test" OR "Montenegro skin test." Articles written in English that describe the history or standardization of leishmanin, the use of leishmanin in an IGRA, or the use of the LST in epidemiological studies or vaccine trials were prioritized in our appraisal of the literature.


Subject(s)
Antigens, Protozoan/analysis , Leishmania/isolation & purification , Leishmaniasis, Cutaneous/diagnosis , Neglected Diseases/diagnosis , Skin Tests/methods , Animals , Humans , Immunity, Cellular , Leishmania/immunology , Leishmania/physiology , Leishmaniasis, Cutaneous/immunology , Leishmaniasis, Cutaneous/parasitology , Neglected Diseases/immunology , Neglected Diseases/parasitology
17.
PLoS Negl Trop Dis ; 15(7): e0009542, 2021 07.
Article in English | MEDLINE | ID: mdl-34197465

ABSTRACT

BACKGROUND: Envenomation by the South American Lonomia saturniid caterpillars, named lonomism, constitutes an emerging and somewhat neglected public health issue in Argentina and neighboring countries. Considering that there is an intricate relationship between environment and human health in such cases, this study aimed to analyze the eco-epidemiological profile of 40 accidents and 33 occurrences of Lonomia spp. in Misiones (Argentina) between January 2014 and May 2020. METHODOLOGY/PRINCIPAL FINDINGS: We described the eco-epidemiological variables and characterized the abiotic scenario of such cases. Additionally, we obtained a density map that shows the punctual intensity of Lonomia records throughout Misiones. Most of the accidents occurred in the Department of Guaraní and involved male victims younger than 20 years old. The accidental/occasional occurrence of Lonomia spp. (considering both adult and caterpillar stages together) was significantly higher in the rural area, whereas only adult specimens were found in urban areas. We determined that the presence of this insect in Misiones is positively related to higher temperatures and solar radiation, and larger precipitation and evapotranspiration throughout the year. CONCLUSION/SIGNIFICANCE: This study represents an initial step towards the global understanding of lonomism as a public health problem in Argentina. It provides a map of the risk level for this envenomation in Misiones, which could help authorities address public health policy efforts to implement sustainable strategies for prevention and response to this threat in Northeastern Argentina and neighboring regions.


Subject(s)
Arthropod Venoms/toxicity , Insect Bites and Stings/parasitology , Larva/physiology , Moths/physiology , Adolescent , Adult , Aged , Animals , Argentina/epidemiology , Child , Child, Preschool , Ecosystem , Female , Humans , Infant , Insect Bites and Stings/epidemiology , Larva/classification , Male , Middle Aged , Moths/classification , Neglected Diseases/epidemiology , Neglected Diseases/parasitology , Public Health , Young Adult
19.
Sci Rep ; 11(1): 6409, 2021 03 19.
Article in English | MEDLINE | ID: mdl-33742015

ABSTRACT

Malaria caused by Plasmodium ovale species is considered a neglected tropical disease with limited information about its characteristics. It also remains unclear whether the two distinct species P. ovale curtisi and P. ovale wallikeri exhibit differences in their prevalence, geographic distribution, clinical characteristics, or laboratory parameters. Therefore, this study was conducted to clarify these differences to support global malaria control and eradication programs. Studies reporting the occurrence of P. ovale curtisi and P. ovale wallikeri were explored in databases. Differences in proportion, clinical data, and laboratory parameters between the two species were estimated using a random-effects model and expressed as pooled odds ratios (ORs), mean difference (MD), or standardized MD depending on the types of extracted data. The difference in geographical distribution was visualized by mapping the origin of the two species. A total of 1453 P. ovale cases extracted from 35 studies were included in the meta-analysis. The p-value in the meta-analyses provided evidence favoring a real difference between P. ovale curtisi malaria cases (809/1453, 55.7%) and P. ovale wallikeri malaria cases (644/1453, 44.3%) (p: 0.01, OR 1.61, 95% CI 0.71-3.63, I2: 77%). Subgroup analyses established evidence favoring a real difference between P. ovale curtisi and P. ovale wallikeri malaria cases among the imported cases (p: 0.02, 1135 cases). The p value in the meta-analyses provided evidence favoring a real difference in the mean latency period between P. ovale curtisi (289 cases) and P. ovale wallikeri malaria (266 cases) (p: 0.03, MD: 27.59, 95% CI 1.99-53.2, I2: 94%), total leukocyte count (p < 0.0001, MD: 840, 95% CI 610-1070, I2: 0%, two studies) and platelet count (p < 0.0001, MD: 44,750, 95% CI 2900-60,500, I2: 32%, three studies). Four continents were found to have reports of P. ovale spp., among which Africa had the highest number of reports for both P. ovale spp. in its 37 countries, with a global proportion of 94.46%, and an almost equal distribution of both P. ovale spp., where P. ovale curtisi and P. ovale wallikeri reflected 53.09% and 46.90% of the continent's proportion, respectively. This is the first systematic review and meta-analysis to demonstrate the differences in the characteristics of the two distinct P. ovale species. Malaria caused by P. ovale curtisi was found in higher proportions among imported cases and had longer latency periods, higher platelet counts, and higher total leukocyte counts than malaria caused by P. ovale wallikeri. Further studies with a larger sample size are required to confirm the differences or similarities between these two species to promote malaria control and effective eradication programs.


Subject(s)
Communicable Diseases, Imported/epidemiology , Malaria/epidemiology , Neglected Diseases/epidemiology , Plasmodium ovale/classification , Plasmodium ovale/genetics , Adolescent , Adult , Africa/epidemiology , Asia/epidemiology , Australia/epidemiology , Child , Child, Preschool , Communicable Diseases, Imported/parasitology , Europe/epidemiology , Female , Genes, Protozoan , Humans , Malaria/parasitology , Male , Middle Aged , Neglected Diseases/parasitology , Polymerase Chain Reaction , Prevalence , RNA, Protozoan/genetics , Young Adult
20.
Exp Parasitol ; 224: 108100, 2021 May.
Article in English | MEDLINE | ID: mdl-33744229

ABSTRACT

Chagas disease and leishmaniasis are neglected diseases caused by parasites of the Trypanosomatidae family and together they affect millions of people in the five continents. The treatment of Chagas disease is based on benznidazole, whereas for leishmaniasis few drugs are available, such as amphotericin B and miltefosine. In both cases, the current treatment is not entirely efficient due to toxicity or side effects. Encouraged by the need to discover valid targets and new treatment options, we evaluated 8 furan compounds against Trypanosoma cruzi and Leishmania amazonensis, considering their effects against proliferation, infection, and ultrastructure. Many of them were able to impair T. cruzi and L. amazonensis proliferation, as well as cause ultrastructural alterations, such as Golgi apparatus disorganization, autophagosome formation, and mitochondrial swelling. Taken together, the results obtained so far make these compounds eligible for further steps of chemotherapy study.


Subject(s)
Furans/pharmacology , Leishmania mexicana/drug effects , Trypanosoma cruzi/drug effects , Cell Line , Chagas Disease/drug therapy , Chagas Disease/parasitology , Chromatography, Thin Layer , Endemic Diseases , Furans/chemistry , Humans , Inhibitory Concentration 50 , Leishmania mexicana/growth & development , Leishmania mexicana/ultrastructure , Leishmaniasis, Cutaneous/drug therapy , Leishmaniasis, Cutaneous/parasitology , Macrophages , Magnetic Resonance Spectroscopy , Microscopy, Electron, Scanning , Molecular Docking Simulation , Neglected Diseases/drug therapy , Neglected Diseases/parasitology , Trypanosoma cruzi/growth & development , Trypanosoma cruzi/ultrastructure
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