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1.
PLoS One ; 19(2): e0281342, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38300957

RESUMO

Coronavirus disease 2019 (COVID-19) pandemic, caused by the Severe Acute Coronavirus 2 (SARS-CoV-2), is a global health threat with extensive misinformation and conspiracy theories. Therefore, this study investigated the knowledge, attitude and perception of sub-Saharan Africans (SSA) on COVID-19 during the exponential phase of the pandemic. In this cross-sectional survey, self-administered web-based questionnaires were distributed through several online platforms. A total of 1046 respondents from 35 SSA countries completed the survey. The median age was 33 years (18-76 years) and about half (50.5%) of them were males. More than 40% across all socio-demographic categories except the Central African region (21.2%), vocational/secondary education (28.6%), student/unemployed (35.5%), had high COVID-19 knowledge score. Socio-demographic factors and access to information were associated with COVID-19 knowledge. Bivariate analysis revealed that independent variables, including the region of origin, age, gender, education and occupation, were significantly (p < 0.05) associated with COVID-19 knowledge. Multivariate analysis showed that residing in East (odds ratio [OR]: 7.9, 95% confidence interval (CI): 4.7-14, p<0.001), Southern (OR: 3.7, 95% CI: 2.1-6.5, p<0.001) and West (OR: 3.9, 95% CI: 2.9-5.2, p<0.001) Africa was associated with high COVID-19 knowledge level. Apart from East Africa (54.7%), willingness for vaccine acceptance across the other SSA regions was <40%. About 52%, across all socio-demographic categories, were undecided. Knowledge level, region of origin, age, gender, marital status and religion were significantly (p < 0.05) associated with COVID-19 vaccine acceptance. About 67.4% were worried about contracting SARS-CoV-2, while 65.9% indicated they would consult a health professional if exposed. More than one-third of the respondents reported that their governments had taken prompt measures to tackle the pandemic. Despite high COVID-19 knowledge in our study population, most participants were still undecided regarding vaccination, which is critical in eliminating the pandemic. Therefore, extensive, accurate, dynamic and timely education in this aspect is of ultimate priority.


Assuntos
COVID-19 , Masculino , Humanos , Adulto , Feminino , COVID-19/epidemiologia , Estudos Transversais , SARS-CoV-2 , Vacinas contra COVID-19 , Conhecimentos, Atitudes e Prática em Saúde , Pandemias , Inquéritos e Questionários , Percepção , África Subsaariana/epidemiologia
2.
Parasit Vectors ; 16(1): 309, 2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37653544

RESUMO

BACKGROUND: The malaria parasite Plasmodium falciparum utilizes multiple alternative receptor-ligand interactions for the invasion of human erythrocytes. While some P. falciparum clones make use of sialic acid (SA) residues on the surface of the human glycophorin receptors to invade the erythrocyte, others use alternative receptors independent of sialic acid residues. We hypothesized that over the years, intensified malaria control interventions and declining prevalence in The Gambia have resulted in a selection of parasites with a dominant invasion pathways and ligand expression profiles. METHODS: Blood samples were collected from 65 malaria-infected participants with uncomplicated malaria across 3 years (2015, 2016, and 2021). Genetic diversity was determined by genotyping the merozoite surface protein 2 (msp2) polymorphic gene of P. falciparum. Erythrocyte invasion phenotypes were determined using neuraminidase, trypsin, and chymotrypsin enzymes, known to cleave different receptors from the surface of the erythrocyte. Schizont-stage transcript levels were obtained for a panel of 6 P. falciparum invasion ligand genes (eba175, eba181, Rh2b, Rh4, Rh5, and clag2) using 48 successfully cultured isolates. RESULTS: Though the allelic heterozygosity of msp2 repeat region decreased as expected with reduced transmission, there was an increase in infections with more than a single msp2 allelotype from 2015 to 2021. The invasion phenotypes of these isolates were mostly SA independent with a continuous increase from 2015 to 2021. Isolates from 2021 were highly inhibited by chymotrypsin treatment compared to isolates from 2015 and 2016. Higher invasion inhibition for 2021 isolates was further obtained following erythrocyte treatment with a combination of chymotrypsin and trypsin. The transcript levels of invasion ligand genes varied across years. However, levels of clag2, a rhoptry-associated protein, were higher in 2015 and 2016 isolates than in 2021 isolates, while Rh5 levels were higher in 2021 compared to other years. CONCLUSIONS: Overall, these findings suggest increasing mixed infections with an increase in the use of sialic-acid independent invasion pathways by P. falciparum clinical isolates in the Western part of Gambia.


Assuntos
Malária Falciparum , Plasmodium falciparum , Humanos , Plasmodium falciparum/genética , Gâmbia/epidemiologia , Ácido N-Acetilneuramínico , Quimotripsina , Ligantes , Tripsina , Malária Falciparum/epidemiologia
3.
PLoS Negl Trop Dis ; 16(4): e0010300, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35442960

RESUMO

BACKGROUND: Animal African Trypanosomiasis (AAT) is one of the most economically important diseases affecting livestock productivity in sub-Saharan Africa. The disease is caused by a broad range of Trypanosoma spp., infecting both wild and domesticated animals through cyclical and mechanical transmission. This study aimed to characterize trypanosomes present in cattle at regular intervals over two years in an AAT endemic and a non-endemic region of Ghana. METHODOLOGY/PRINCIPAL FINDINGS: Groups of cattle at Accra and Adidome were selected based on their geographical location, tsetse fly density, prevalence of trypanosomiasis and the breed of cattle available. Blood for DNA extraction was collected at approximately four to five-week intervals over a two-year period. Trypanosome DNA were detected by a sensitive nested PCR targeting the tubulin gene array and massively parallel sequencing of barcoded amplicons. Analysis of the data was a semi-quantitative estimation of infection levels using read counts obtained from the sequencing as a proxy for infection levels. Majority of the cattle were infected with multiple species most of the time [190/259 (73%) at Adidome and 191/324 (59%) at Accra], with T. vivax being the most abundant. The level of infection and in particular T. vivax, was higher in Adidome, the location with a high density of tsetse flies. The infection level varied over the time course, the timings of this variation were not consistent and in Adidome it appeared to be independent of prophylactic treatment for trypanosome infection. Effect of gender or breed on infection levels was insignificant. CONCLUSIONS/SIGNIFICANCE: Most cattle were infected with low levels of several trypanosome species at both study sites, with T. vivax being the most abundant. The measurements of infection over time provided insight to the importance of the approach in identifying cattle that could suppress trypanosome infection over an extended time and may serve as reservoir.


Assuntos
Trypanosoma , Tripanossomíase Africana , Moscas Tsé-Tsé , Animais , Bovinos , Gana/epidemiologia , Sequenciamento de Nucleotídeos em Larga Escala , Prevalência , Trypanosoma/genética , Tripanossomíase Africana/epidemiologia , Tripanossomíase Africana/veterinária , Moscas Tsé-Tsé/genética
4.
PLoS One ; 16(11): e0258996, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34807936

RESUMO

In the midst of numerous setbacks that beclouds the fight against leishmaniasis; a neglected tropical disease, the search for new chemotherapeutics against this disease is of utmost importance. Leishmaniasis is a disease closely associated with poverty and endemic in Africa, Asia, southern Europe and the Americas. It is caused by parasites of the genus Leishmania and transmitted by a sandfly vector. In this study, we evaluated the antileishmanial potency of eighteen pathogen box compounds and elucidated their biosafety and possible mechanisms of action against Leishmania donovani promastigotes and amastigotes in vitro. IC50s range of 0.12±0.15 to >6.25 µg/ml and 0.13±0.004 to >6.25µg/ml were observed for the promastigotes and amastigotes, respectively. We demonstrated the ability of some of the compounds to cause cytocidal effect on the parasites, induce increased production of reactive oxygen species (ROS), disrupt the normal parasite morphology and cause the accumulation of parasites at the DNA synthesis phase of the cell cycle. We recommend a further in vivo study on these compounds to validate the findings.


Assuntos
Antiprotozoários/farmacologia , Ciclo Celular , Leishmania donovani/citologia , Ciclo Celular/efeitos dos fármacos , DNA de Cinetoplasto/metabolismo , Humanos , Concentração Inibidora 50 , Cinética , Leishmania donovani/efeitos dos fármacos , Leishmania donovani/crescimento & desenvolvimento , Macrófagos/efeitos dos fármacos , Macrófagos/parasitologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Oxirredução/efeitos dos fármacos , Fosfatidilserinas/metabolismo , Espécies Reativas de Oxigênio/metabolismo
5.
PLoS One ; 14(4): e0215550, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31002731

RESUMO

BACKGROUND: The overlap of malaria and chronic hepatitis B (CHB) is common in endemic regions, however, it is not known if this co-infection could adversely influence clinical and immunological responses. This study investigated these interactions in pregnant women reporting to antenatal clinics in Ghana. METHODS: Clinical parameters (hemoglobin, liver function biomarker, peripheral malaria parasitemia, and hepatitis B viremia) and cytokine profiles were assayed and compared across four categories of pregnant women: un-infected, mono-infected with Plasmodium falciparum (Malaria group), mono-infected with chronic hepatitis B virus (CHB group) and co-infected (Malaria+CHB group). RESULTS: Women with Malaria+CHB maintained appreciably normal hemoglobin levels (mean±SEM = 10.3±0.3 g/dL). That notwithstanding, Liver function test showed significantly elevated levels of alanine aminotransferase, aspartate aminotransferase and total bilirubin [P<0.001 for all comparisons]. Similarly, the Malaria+CHB group had significantly elevated pro-inflammatory cytokines, including tumour necrosis factor alpha (TNF-α), interleukin (IL)-1ß, and IL-6 [P<0.05 for all comparisons]. In women with Malaria+CHB, correlation analysis showed significant negative association of the pro-inflammatory cytokines responses with malaria parasitemia [IL-1ß (P<0.001; r = -0.645), IL-6 (P = 0.046; r = -0.394) and IL-12 (P = 0.011; r = -0.49)]. On the other hand, the pro-inflammatory cytokine levels positively correlated with HBV viremia [TNF-α (P = 0.004; r = 0.549), IL-1ß (P<0.001; r = 0.920), IL-6 (P<0.001; r = 0.777), IFN-γ (P = 0.002; r = 0.579), IL-2 (P = 0.008; r = 0.512) and IL-12 (P<0.001; r = 0.655)]. Also, for women in the Malaria+CHB group, parasitemia was observed to diminish HBV viremia [P = 0.003, r = -0.489]. CONCLUSION: Put together the findings suggests that Malaria+CHB could exacerbate inflammatory cytokine responses and increase susceptibility to liver injury among pregnant women in endemic settings.


Assuntos
Coinfecção/sangue , Hepatite B Crônica/sangue , Malária Falciparum/sangue , Cuidado Pré-Natal/estatística & dados numéricos , Adulto , Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Coinfecção/epidemiologia , Coinfecção/fisiopatologia , Citocinas/sangue , Feminino , Gana/epidemiologia , Hemoglobinas/metabolismo , Hepatite B Crônica/epidemiologia , Hepatite B Crônica/fisiopatologia , Humanos , Mediadores da Inflamação/sangue , Malária Falciparum/epidemiologia , Malária Falciparum/fisiopatologia , Gravidez , Resultado da Gravidez , Adulto Jovem
6.
PLoS One ; 14(2): e0210365, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30726218

RESUMO

BACKGROUND: High prevalence of malaria and hepatitis B has been reported among pregnant women in Ghana. In endemic areas, the diagnoses of malaria and hepatitis B among pregnant women on antenatal visits are done using histidine-rich protein 2 (HRP2) and hepatitis B surface antigen (HBsAg) rapid diagnostic tests (RDTs), respectively, which are, however, reported to give some false positive results. Also, socio-economic determinants have been drawn from these RDTs results which may have questionable implications. Thus, this study was aimed at evaluating the prevalence of malaria and hepatitis B by comparing RDTs with polymerase chain reaction (PCR) outcomes, and relating the PCR prevalence with socio-economic status among pregnant women in Northern Ghana. METHODS: We screened 2071 pregnant women on their first antenatal visit for Plasmodium falciparum and hepatitis B virus (HBV) using HRP2 and HBsAg RDTs, and confirming the infections with PCR. Socio-economic and obstetric information were collected using a pre-tested questionnaire, and associations with the infections were determined using Pearson's chi-square and multinomial logistic regression analyses at a significance level of p<0.05. RESULTS: The prevalence of the infections by RDTs/PCR was: 14.1%/13.4% for P. falciparum mono-infection, 7.9%/7.5% for HBV mono-infection, and 1.9%/1.7% for P. falciparum/HBV co-infection. No statistical difference in prevalence rates were observed between the RDTs and PCRs (χ2 = 0.119, p = 0.73 for malaria and χ2 = 0.139, p = 0.709 for hepatitis B). Compared with PCRs, the sensitivity/specificity of the RDTs was 97.5%/99.1% and 97.9%/99.4% for HRP2 and HBsAg respectively. Socio-economic status was observed not to influence HBV mono-infection among the pregnant women (educational status: AOR = 0.78, 95% CI = 0.52-1.16, p = 0.222; economic status: AOR = 1.07, 95% CI = 0.72-1.56, p = 0.739; financial status: AOR = 0.66, 95% CI = 0.44-1.00, p = 0.052). However, pregnant women with formal education were at a lower risk for P. falciparum mono-infection (AOR = 0.48, 95% CI = 0.32-0.71, p<0.001) and P. falciparum/HBV co-infection (AOR = 0.27, 95% CI = 0.11-0.67, p = 0.005). Also those with good financial status were also at a lower risk for P. falciparum mono-infection (AOR = 0.52, 95% CI = 0.36-0.74, p<0.001). CONCLUSION: Our data has shown that, the RDTs are comparable to PCR and can give a representative picture of the prevalence of malaria and hepatitis B in endemic countries. Also, our results support the facts that improving socio-economic status is paramount in eliminating malaria in endemic settings. However, socio-economic status did not influence the prevalence of HBV mono-infection among pregnant women in Northern Ghana.


Assuntos
Hepatite B/epidemiologia , Malária Falciparum/epidemiologia , Complicações Infecciosas na Gravidez/epidemiologia , Adulto , Antígenos de Protozoários/sangue , Estudos Transversais , Feminino , Gana/epidemiologia , Hepatite B/sangue , Antígenos de Superfície da Hepatite B/sangue , Humanos , Malária Falciparum/sangue , Gravidez , Complicações Infecciosas na Gravidez/sangue , Proteínas de Protozoários/sangue
7.
BMC Infect Dis ; 18(1): 392, 2018 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-30103683

RESUMO

BACKGROUND: The decline in the efficacy of artemisinin-based combination treatment (ACT) in some endemic regions threatens the progress towards global elimination of malaria. Molecular surveillance of drug resistance in malaria-endemic regions is vital to detect the emergence and spread of mutant strains. METHODS: We observed 89 malaria patients for the efficacy of artemether-lumefantrine for the treatment of uncomplicated Plasmodium falciparum infections in Lagos, Nigeria and determined the prevalence of drug resistant strains in the population. Parasite clearance rates were determined by microscopy and the highly sensitive var gene acidic terminal sequence (varATS) polymerase chain reaction for 65 patients with samples on days 0, 1, 3, 7, 14, 21 and 28 after commencement of treatment. The genomic finger print of parasite DNA from pre- and post-treatment samples were determined using 24 nuclear single nucleotide polymorphisms (SNP) barcode for P. falciparum. Drug resistance associated alleles in chloroquine resistance transporter gene (crt-76), multidrug resistance genes (mdr1-86 and mdr1-184), dihydropteroate synthase (dhps-540), dihydrofolate reductase (dhfr-108) and kelch domain (K-13580) were genotyped by high resolution melt analysis of polymerase chain reaction (PCR) fragments. RESULTS: By varATS qPCR, 12 (18.5%) of the participants had detectable parasite DNA in their blood three days after treatment, while eight (12.3%) individuals presented with genotypable day 28 parasitaemia. Complexity of infection (CoI) was 1.30 on day 0 and 1.34 on day 28, the mean expected heterozygosity (HE) values across all barcodes were 0.50 ± 0.05 and 0.56 ± 0.05 on days 0 and 28 respectively. Barcode (π) pairwise comparisons showed high genetic relatedness of day 0 and day 28 parasite isolates in three (37.5%) of the eight individuals who presented with re-appearing infections. Crt-76 mutant allele was present in 38 (58.5%) isolates. The mdr1-86 mutant allele was found in 56 (86.2%) isolates. No mutation in the K-13580 was observed. CONCLUSIONS: Persistence of DNA-detectable parasitaemia in more than 18% of cases after treatment and indications of genetic relatedness between pre- and post-treatment infections warrants further investigation of a larger population for signs of reduced ACT efficacy in Nigeria.


Assuntos
Antimaláricos/uso terapêutico , Artemeter/uso terapêutico , Código de Barras de DNA Taxonômico , Resistência a Medicamentos/genética , Lumefantrina/uso terapêutico , Malária Falciparum/parasitologia , Plasmodium falciparum/genética , Adolescente , Adulto , Idoso , Alelos , Criança , Pré-Escolar , DNA de Protozoário/classificação , DNA de Protozoário/isolamento & purificação , Di-Hidropteroato Sintase/genética , Combinação de Medicamentos , Feminino , Genótipo , Humanos , Lactente , Malária Falciparum/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Mutação , Nigéria , Plasmodium falciparum/classificação , Plasmodium falciparum/isolamento & purificação , Reação em Cadeia da Polimerase , Polimorfismo de Nucleotídeo Único , Adulto Jovem
8.
J Clin Lab Anal ; 32(8): e22582, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29862574

RESUMO

BACKGROUND: Although hematological indices cannot in entirety be used to diagnose diseases or defects, the appropriate interpretation of these indices could complement diagnostics such as microscopy and serology for numerous illnesses in children. This study sought to evaluate distinct hematological indices characterizing different childhood illnesses. METHODS: Full blood counts from 150 children (age range from 1 to 15 year) presenting different disease conditions at the Tamale Central Hospital were assessed. The hematological indices were compared between disease categories, and relationships between disease indicators were determined. RESULTS: The prevalence of the diagnosed childhood illness were: 50.7% malaria, 20.0% diarrhea, 13.3% typhoid fever, 10.0% Sickle Cell Disease (SCD), and 6.0% malaria-typhoid co-infection. Fever was diagnosed in a majority (66.0%) of the children, but was independent of each disease group, (χ2 = 9.18, P = .057). Of the 24 hematological indices analyzed, eight; red blood cell (RBC) (P < .001), hemoglobin (Hb) (P < .001), mean cell volume (MCV) (P = .002), mean cell hemoglobin (MCH) (P < .001; lowest and below normal range for SCD), red cell distribution width (RDW_CV) (P < .001), eosinophil percentage [EOS (%)] (P = .001), eosinophil number [EOS#] (P = .002), and platelets (PLT) (P = .001; lowest for malaria) differed significantly across the different disease groups. Levels of Hb and/or MCV were below the normal reference ranges for most of the diagnosed diseases. In addition, low PLT and MCH were respectively distinct for children with malaria and SCD. CONCLUSION: Hematological indices including Hb, MCV and PLT, or MCH may be useful indices that could incite further diagnostic tests for malaria or SCD among children in Ghana.


Assuntos
Índices de Eritrócitos , Malária/sangue , Febre Tifoide/sangue , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Feminino , Gana/epidemiologia , Humanos , Lactente , Malária/epidemiologia , Malária/fisiopatologia , Masculino , Prevalência , Febre Tifoide/epidemiologia , Febre Tifoide/fisiopatologia
9.
Parasit Vectors ; 10(1): 312, 2017 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-28655350

RESUMO

BACKGROUND: Animal African trypanosomiasis (AAT) greatly affects livestock production in sub-Saharan Africa. In Ghana prevalence of AAT is estimated to range between 5 and 50%. Studies have reported serum biochemical aberrations and variability in cytokine profiles in animals during infection. However, information regarding the biochemical parameters and cytokine profiles associated with natural infections are limited. This study was therefore aimed at investigating changes in the levels of serum biochemical parameters and inflammatory cytokines during a natural infection. METHODS: Nested internal transcribed spacer (ITS)-based PCR and sequencing were used to characterise trypanosome infection in cattle at two areas in Ghana (Adidome and Accra) of different endemicities. The cattle were sampled at four to five-week intervals over a period of six months. Levels of serum biochemical parameters, including creatinine, cholesterol, alkaline phosphatase (ALP), alanine aminotransferase (ALT), total bilirubin and total protein and cytokines (interleukin 10, interleukin 4, interleukin 12, interferon gamma and tumor necrosis factor alpha) were measured in serum samples and then compared between infected cattle and uninfected controls. RESULTS: The predominant trypanosome species detected in Accra (non-endemic) and Adidome (endemic) were Trypanosoma theileri and Trypanosoma vivax, respectively. Serum biochemical parameters were similar between infected and uninfected cattle in Accra. Infected cattle at Adidome however, had significantly higher levels of ALP, creatinine, total protein and total bilirubin (P < 0.05) and significantly lower levels of cholesterol (P < 0.05) at specific time points. At basal levels and during infection, significantly higher pro-inflammatory to anti-inflammatory (Th1/Th2) cytokine ratios were observed in cattle at Adidome compared to Accra (P < 0.05), indicating a shift towards Th1 immune response in Adidome. Levels of IL-10 were, however, significantly elevated in infected cattle in Accra (P < 0.05), suggesting high anti-inflammatory cytokine response in Accra. CONCLUSION: These results suggests that cattle in an endemic area repeatedly infected with trypanosomes of different species or different antigenic types demonstrate high pro-inflammatory (Th1) immune response and biochemical alterations whereas cattle in a non-endemic area with predominantly chronic T. theileri infections demonstrate high anti-inflammatory response and no biochemical alterations.


Assuntos
Doenças dos Bovinos/sangue , Citocinas/sangue , Trypanosoma/imunologia , Tripanossomíase Africana/veterinária , Tripanossomíase Bovina/sangue , Alanina Transaminase/sangue , Fosfatase Alcalina/sangue , Animais , Bilirrubina/sangue , Análise Química do Sangue/veterinária , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/imunologia , Colesterol/sangue , Creatinina/sangue , Feminino , Gana/epidemiologia , Estudos Longitudinais , Masculino , Prevalência , Trypanosoma/isolamento & purificação , Trypanosoma vivax/imunologia , Trypanosoma vivax/isolamento & purificação , Tripanossomíase Africana/sangue , Tripanossomíase Africana/epidemiologia , Tripanossomíase Africana/imunologia , Tripanossomíase Bovina/epidemiologia , Tripanossomíase Bovina/imunologia
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