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1.
Antimicrob Agents Chemother ; 68(9): e0004424, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39046237

RESUMO

The emergence and spread of chloroquine-resistant Plasmodium vivax have necessitated the assessment of alternative blood schizonticidal drugs. In Vietnam, chloroquine-resistant P. vivax malaria has been reported. In an open-label, single-arm trial, the safety, tolerability, and efficacy of pyronaridine-artesunate (Pyramax, PA) was evaluated in Dak Nong province, Vietnam. A 3-day course of PA was administered to adults and children (≥20 kg) infected with P. vivax. Patients also received primaquine (0.25 mg/kg daily for 14 days). PA was well tolerated with transient asymptomatic increases in liver transaminases. The per-protocol proportion of patients with day 42 PCR-unadjusted adequate clinical and parasitological response was 96.0% (95% CI, 84.9%-99.0%, n = 48/50). The median parasite clearance time was 12 h (range, 12-36 h), with a median fever clearance time of 24 h (range, 12-60 h). Single nucleotide polymorphisms (SNPs) as potential genetic markers of reduced drug susceptibility were analyzed in three putative drug resistance markers, Pvcrt-o, Pvmdr1, and PvK12. Insertion at position K10 of the Pvcrt-o gene was found in 74.6% (44/59) of isolates. Pvmdr1 SNPs at Y976F and F1076L were present in 61% (36/59) and 78% (46/59), respectively. Amplification of Pvmdr1 gene (two copies) was found in 5.1% (3/59) of parasite samples. Only 5.1% (3/59) of isolates had mutation 552I of the PvK12 gene. Overall, PA rapidly cleared P. vivax blood asexual stages and was highly efficacious in treating vivax malaria, with no evidence of artemisinin resistance found. PA provides an alternative to chloroquine treatment for vivax malaria in Vietnam. CLINICAL TRIALS: This study is registered with the Australian New Zealand Clinical Trials Registry as ACTRN12618001429246.


Assuntos
Antimaláricos , Artemisininas , Artesunato , Malária Vivax , Naftiridinas , Plasmodium vivax , Humanos , Malária Vivax/tratamento farmacológico , Malária Vivax/parasitologia , Naftiridinas/uso terapêutico , Antimaláricos/uso terapêutico , Artesunato/uso terapêutico , Vietnã , Adulto , Plasmodium vivax/efeitos dos fármacos , Plasmodium vivax/genética , Masculino , Artemisininas/uso terapêutico , Adolescente , Criança , Feminino , Pessoa de Meia-Idade , Adulto Jovem , Primaquina/uso terapêutico , Polimorfismo de Nucleotídeo Único/genética , Pré-Escolar , Proteínas de Protozoários/genética , Resistência a Medicamentos/genética , Proteínas de Membrana Transportadoras
2.
BMC Infect Dis ; 24(1): 1216, 2024 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-39468465

RESUMO

BACKGROUND: Plasmodium falciparum merozoite surface proteins 1 (PfMSP1) and 2 (PfMSP2) are potential candidates for malaria vaccine development. However, the genetic diversity of these genes in the global P. falciparum population presents a significant challenge in developing an effective vaccine. Hence, understanding the genetic diversity and evolutionary trends in the global P. falciparum population is crucial. METHODS: This study analyzed the genetic variations and evolutionary changes of pfmsp1 and pfmsp2 in P. falciparum isolates from the Central Highland and South-Central regions of Vietnam. DNASTAR and MEGA7 programs were utilized for analyses. The polymorphic nature of global pfmsp1 and pfmsp2 was also investigated. RESULTS: A total of 337 sequences of pfmsp1 and 289 sequences of pfmsp2 were obtained. The pfmsp1 and pfmsp2 from Vietnam revealed a higher degree of genetic homogeneity compared to those from other malaria-endemic countries. Remarkably, the allele diversity patterns of Vietnam pfmsp1 and pfmsp2 differed significantly from those of neighboring countries in the Greater Mekong Subregion. Declines in allele diversity and polymorphic patterns of Vietnam pfmsp1 and pfmsp2 were observed. CONCLUSIONS: The Vietnam P. falciparum population might be genetically isolated from the parasite populations in other neighboring GMS countries, likely due to geographical barriers and distinct evolutionary pressures. Furthermore, bottleneck effects or selective sweeps may have contributed to the genetic homogeneity of Vietnam pfmsp1 and pfmsp2.


Assuntos
Antígenos de Protozoários , Malária Falciparum , Proteína 1 de Superfície de Merozoito , Plasmodium falciparum , Polimorfismo Genético , Proteínas de Protozoários , Vietnã/epidemiologia , Plasmodium falciparum/genética , Proteína 1 de Superfície de Merozoito/genética , Proteínas de Protozoários/genética , Antígenos de Protozoários/genética , Humanos , Malária Falciparum/parasitologia , Malária Falciparum/epidemiologia , Variação Genética
3.
Environ Monit Assess ; 194(8): 561, 2022 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-35789439

RESUMO

A coal-fired power plant's operation can release radioactive nuclides and radon gas into the environment, affecting the surrounding ecosystem. In this work, the collective effective dose due to the inhalation and the consumption of food containing the deposited radionuclides from the atmospheric release of the plants were evaluated. The results show that the radioactivity concentration in coal and fly ash samples depends on the origin of feed coal. The distribution of Th and U radionuclides in the 6a1 dust coal and bituminous coal is different. In general, the collective effective dose for different organs due to radiation exposure from the atmospheric release of two surveyed CFPP complexes are lower than the corresponding value published by UNSCEAR.


Assuntos
Ecossistema , Exposição à Radiação , Carvão Mineral/análise , Monitoramento Ambiental , Centrais Elétricas , Radioisótopos/análise , Vietnã
4.
Artigo em Inglês | MEDLINE | ID: mdl-33526483

RESUMO

Plasmodium falciparum resistance to dihydroartemisinin-piperaquine has spread through the Greater Mekong Subregion to southwestern Vietnam. In 2018 to 2019, we collected 127 P. falciparum isolates from Dak Nong (36), Dak Lak (55), Gia Lai (13), and Kon Tum (23) provinces in Vietnam's Central Highlands and found parasites bearing the Pfkelch13 C580Y mutation and multiple plasmepsin 2/3 genes (mean prevalence, 17.9%; range, 4.3% to 27.8%), conferring resistance to dihydroartemisinin-piperaquine. This information is important for drug policy decisions in Vietnam.


Assuntos
Antimaláricos , Malária Falciparum , Malária , Parasitos , Quinolinas , Animais , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Resistência a Medicamentos/genética , Malária/tratamento farmacológico , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Malária Falciparum/prevenção & controle , Plasmodium falciparum/genética , Proteínas de Protozoários/uso terapêutico , Quinolinas/farmacologia , Quinolinas/uso terapêutico , Vietnã/epidemiologia
5.
Antimicrob Agents Chemother ; 65(12): e0027621, 2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34570647

RESUMO

The rise in Plasmodium falciparum resistance to dihydroartemisinin-piperaquine in Vietnam justifies the need to evaluate alternative artemisinin-based combination therapies. Between July 2018 and October 2019, a single-arm trial of pyronaridine-artesunate (Pyramax, PA) was conducted in Dak Nong province, Vietnam. PA (3-day course) was administered to adults and children infected with P. falciparum. PA was well tolerated by the participants. The proportion of patients with Day 42 PCR-corrected adequate clinical and parasitological response was 95.2% (95% confidence interval [CI], 82.3 to 98.8, n = 40/42) for treating falciparum malaria. The median parasite clearance half-life was 6.7 h (range, 2.6 to 11.9) and the median parasite clearance time was 72 h (range, 12 to 132) with 44.9% (22/49) of patients having positive blood films at 72 h. The two patients that recrudesced had comparable Day 7 blood pyronaridine concentrations (39.5 and 39.0 ng/ml) to the 40 patients who did not recrudesce (median 43.4 ng/ml, 95% CI, 35.1 to 54.9). Ring-stage and piperaquine survival assays revealed that of the 29 P. falciparum isolates collected from the patients before PA treatment, 22 (75.9%) had reduced susceptibility to artemisinins and 17 (58.6%) were resistant to piperaquine. Genotyping confirmed that 92.0% (46/50) of falciparum patients were infected with parasites bearing the Pfkelch13 C580Y mutation associated with artemisinin resistance. Of these, 56.0% (28/50) of the isolates also had multiple copies of the plasmepsin 2/3 genes responsible for piperaquine resistance. Overall, PA was effective in treating P. falciparum in the Central Highlands of Vietnam. (This study has been registered at AustralianClinicalTrials.gov.au under trial ID ACTRN12618001429246.).


Assuntos
Antimaláricos , Artemisininas , Malária Falciparum , Quinolinas , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Artesunato , Combinação de Medicamentos , Humanos , Malária Falciparum/tratamento farmacológico , Naftiridinas , Plasmodium falciparum/genética , Quinolinas/uso terapêutico , Vietnã
6.
Trop Med Int Health ; 26(11): 1419-1426, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34370367

RESUMO

OBJECTIVES: Human toxocariasis is a widespread zoonosis for which a chemotherapy decision and therapy effectiveness are difficult to determine. We aimed to investigate the kinetic profile of clinical and laboratory findings and treatment outcome of patients with toxocariasis in Vietnam. METHODS: The prospective study was conducted between October 2017 and June 2019. The diagnosis of toxocariasis was established based on clinical, laboratory (eosinophilia, raised IgE concentration) and serological (positive Toxocara IgG ELISA) evaluation as well as the exclusion of another helminthic co-infection. The patients were followed up after seven days, then one, three and six months after chemotherapy by thiabendazole. RESULTS: The study involved 80 patients with a mean age of 41.6 ± 15.2 years of whom 58.8% were female. At three and six months after chemotherapy, most patients demonstrated resolution of clinical signs and symptoms, eosinophil count and IgE concentration but not in the proportion of IgG seropositivity. Skin lesions and eosinophilia resolved earlier than the other symptoms (one month after treatment). About four-fifths of the patients were "cured" after three and six months of follow-up; 33.8% showed side effects to thiabendazole therapy but no severe events were reported. The most common adverse reaction was neurologic symptoms followed by gastrointestinal or skin manifestations which lasted as long as 4 days. CONCLUSIONS: In toxocariasis patients, cutaneous manifestations and eosinophilia resolve more rapidly than other clinical and laboratory findings while IgG titre has a very slow kinetic after therapy. Thiabendazole seems to be a potential alternative for the treatment of human toxocariasis.


Assuntos
Toxocaríase/diagnóstico , Adolescente , Adulto , Idoso , Animais , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/uso terapêutico , Anticorpos Anti-Helmínticos/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Tiabendazol/administração & dosagem , Tiabendazol/uso terapêutico , Toxocara/imunologia , Toxocaríase/sangue , Toxocaríase/tratamento farmacológico , Toxocaríase/epidemiologia , Vietnã/epidemiologia , Adulto Jovem , Zoonoses/diagnóstico , Zoonoses/tratamento farmacológico
7.
Malar J ; 19(1): 271, 2020 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-32718342

RESUMO

The Asia-Pacific region faces formidable challenges in achieving malaria elimination by the proposed target in 2030. Molecular surveillance of Plasmodium parasites can provide important information on malaria transmission and adaptation, which can inform national malaria control programmes (NMCPs) in decision-making processes. In November 2019 a parasite genotyping workshop was held in Jakarta, Indonesia, to review molecular approaches for parasite surveillance and explore ways in which these tools can be integrated into public health systems and inform policy. The meeting was attended by 70 participants from 8 malaria-endemic countries and partners of the Asia Pacific Malaria Elimination Network. The participants acknowledged the utility of multiple use cases for parasite genotyping including: quantifying the prevalence of drug resistant parasites, predicting risks of treatment failure, identifying major routes and reservoirs of infection, monitoring imported malaria and its contribution to local transmission, characterizing the origins and dynamics of malaria outbreaks, and estimating the frequency of Plasmodium vivax relapses. However, the priority of each use case varies with different endemic settings. Although a one-size-fits-all approach to molecular surveillance is unlikely to be applicable across the Asia-Pacific region, consensus on the spectrum of added-value activities will help support data sharing across national boundaries. Knowledge exchange is needed to establish local expertise in different laboratory-based methodologies and bioinformatics processes. Collaborative research involving local and international teams will help maximize the impact of analytical outputs on the operational needs of NMCPs. Research is also needed to explore the cost-effectiveness of genetic epidemiology for different use cases to help to leverage funding for wide-scale implementation. Engagement between NMCPs and local researchers will be critical throughout this process.


Assuntos
Monitoramento Epidemiológico , Genótipo , Malária Falciparum/epidemiologia , Malária Vivax/epidemiologia , Plasmodium falciparum/genética , Plasmodium vivax/genética , Vigilância da População , Ásia/epidemiologia , Congressos como Assunto , Retroalimentação , Malária Falciparum/parasitologia , Malária Vivax/parasitologia , Ilhas do Pacífico/epidemiologia
8.
PLoS Med ; 16(2): e1002745, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30768615

RESUMO

BACKGROUND: The emergence and spread of multidrug-resistant Plasmodium falciparum in the Greater Mekong Subregion (GMS) threatens global malaria elimination efforts. Mass drug administration (MDA), the presumptive antimalarial treatment of an entire population to clear the subclinical parasite reservoir, is a strategy to accelerate malaria elimination. We report a cluster randomised trial to assess the effectiveness of dihydroartemisinin-piperaquine (DP) MDA in reducing falciparum malaria incidence and prevalence in 16 remote village populations in Myanmar, Vietnam, Cambodia, and the Lao People's Democratic Republic, where artemisinin resistance is prevalent. METHODS AND FINDINGS: After establishing vector control and community-based case management and following intensive community engagement, we used restricted randomisation within village pairs to select 8 villages to receive early DP MDA and 8 villages as controls for 12 months, after which the control villages received deferred DP MDA. The MDA comprised 3 monthly rounds of 3 daily doses of DP and, except in Cambodia, a single low dose of primaquine. We conducted exhaustive cross-sectional surveys of the entire population of each village at quarterly intervals using ultrasensitive quantitative PCR to detect Plasmodium infections. The study was conducted between May 2013 and July 2017. The investigators randomised 16 villages that had a total of 8,445 residents at the start of the study. Of these 8,445 residents, 4,135 (49%) residents living in 8 villages, plus an additional 288 newcomers to the villages, were randomised to receive early MDA; 3,790 out of the 4,423 (86%) participated in at least 1 MDA round, and 2,520 out of the 4,423 (57%) participated in all 3 rounds. The primary outcome, P. falciparum prevalence by month 3 (M3), fell by 92% (from 5.1% [171/3,340] to 0.4% [12/2,828]) in early MDA villages and by 29% (from 7.2% [246/3,405] to 5.1% [155/3,057]) in control villages. Over the following 9 months, the P. falciparum prevalence increased to 3.3% (96/2,881) in early MDA villages and to 6.1% (128/2,101) in control villages (adjusted incidence rate ratio 0.41 [95% CI 0.20 to 0.84]; p = 0.015). Individual protection was proportional to the number of completed MDA rounds. Of 221 participants with subclinical P. falciparum infections who participated in MDA and could be followed up, 207 (94%) cleared their infections, including 9 of 10 with artemisinin- and piperaquine-resistant infections. The DP MDAs were well tolerated; 6 severe adverse events were detected during the follow-up period, but none was attributable to the intervention. CONCLUSIONS: Added to community-based basic malaria control measures, 3 monthly rounds of DP MDA reduced the incidence and prevalence of falciparum malaria over a 1-year period in areas affected by artemisinin resistance. P. falciparum infections returned during the follow-up period as the remaining infections spread and malaria was reintroduced from surrounding areas. Limitations of this study include a relatively small sample of villages, heterogeneity between villages, and mobility of villagers that may have limited the impact of the intervention. These results suggest that, if used as part of a comprehensive, well-organised, and well-resourced elimination programme, DP MDA can be a useful additional tool to accelerate malaria elimination. TRIAL REGISTRATION: ClinicalTrials.gov NCT01872702.


Assuntos
Antimaláricos/administração & dosagem , Erradicação de Doenças/métodos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Administração Massiva de Medicamentos/métodos , Adolescente , Adulto , Sudeste Asiático/epidemiologia , Criança , Análise por Conglomerados , Estudos Cross-Over , Resistência a Múltiplos Medicamentos/fisiologia , Feminino , Humanos , Malária Falciparum/diagnóstico , Masculino , Adulto Jovem
9.
Malar J ; 18(1): 10, 2019 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-30654808

RESUMO

BACKGROUND: Reduced artemisinin susceptibility and artemisinin-based combination therapy (ACT)-resistance against Plasmodium falciparum and chloroquine (CQ)-resistant P. vivax malaria has been reported in Vietnam. Two therapeutic efficacy studies were conducted in Thuan Bac District (Ninh Thuan Province, Vietnam) in 2015 and 2016 to determine the extent of reduced artemisinin susceptibility and ACT resistant falciparum malaria, and CQ-resistant vivax malaria were present. METHODS: Twenty-seven patients with falciparum malaria were randomized to receive artesunate alone (AS ~ 4 mg/kg/day) for 4 days followed by dihydroartemisinin (DHA) (2.2 mg/kg)-piperaquine (PPQ) (18 mg/kg) daily for 3 days or artemether (AM) (1.7 mg/kg)-lumefantrine (LUM) (12 mg/kg) twice daily for 3 days. Sixteen subjects with vivax malaria received CQ (total 25 mg/kg over 3 days). The therapeutic efficacy study for treating falciparum malaria was complemented with molecular analysis for artemisinin and piperaquine resistance, and in vitro drug susceptibility testing. Patient's drug exposure following both falciparum and vivax treatment studies was determined. RESULTS: Twenty-five of 27 patients treated with the artemisinin regimens completed the 42-day follow-up period. None had parasites present on day 3 after commencing treatment with no incidence of recrudescence (100% curative rate). One patient on AS + DHA-PPQ was lost to follow-up and one patient had Plasmodium falciparum and Plasmodium vivax infection on day 0 by PCR. Of the vivax patients, 15 of 16 completed CQ treatment and two had a recurrence of vivax malaria on day 28, a failure rate of 13.3% (2/15). No mutations in the Pfkelch-13 gene for artemisinin resistance or exo-E415G gene polymorphism and amplification in plasmepsins 2 and 3 for piperaquine resistance were observed. In vitro testing of patient's falciparum parasites indicated susceptibility (low IC50 nM values) to dihydroartemisinin, lumefantrine, piperaquine and pyronaridine. Patient's drug exposure to artesunate and lumefantrine was comparable to published data, however, blood CQ concentrations were lower. CONCLUSIONS: Clinical findings, molecular analysis and in vitro testing revealed that the falciparum parasites at Phuoc Chien Commune were artemisinin susceptible. The clinical failure rate of the 15 vivax patients who completed CQ treatment was 13%. Further studies are required to determine whether CQ-resistant vivax malaria is present at the commune.


Assuntos
Antimaláricos/uso terapêutico , Cloroquina/uso terapêutico , Malária Falciparum/tratamento farmacológico , Malária Vivax/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Plasmodium vivax/efeitos dos fármacos , Adolescente , Adulto , Idoso , Antimaláricos/farmacologia , Criança , Pré-Escolar , Cloroquina/farmacologia , Resistência a Múltiplos Medicamentos/genética , Etanolaminas/farmacologia , Etanolaminas/uso terapêutico , Feminino , Fluorenos/farmacologia , Fluorenos/uso terapêutico , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Quinolinas/farmacologia , Quinolinas/uso terapêutico , Reação em Cadeia da Polimerase em Tempo Real , Vietnã/epidemiologia , Adulto Jovem
10.
Malar J ; 18(1): 20, 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-30674319

RESUMO

BACKGROUND: Plasmodium vivax malaria elimination can only be achieved by the deployment of 8-aminoquinolines (primaquine and tafenoquine) in combination with ACT to kill both blood and liver-stage parasites. However, primaquine and the other 8-aminoquinolines cause dose-dependent haemolysis in subjects with G6PD deficiency, an X-linked disorder of red blood cells that is very common in populations living in tropical and subtropical areas. In order to inform safer use of 8-aminoquinolines in the Greater Mekong Subregion, a multi-centre study was carried out to assess the prevalence of G6PD deficiency and to identify the main G6PD variants in samples collected in Cambodia, Lao PDR, Myanmar, Thailand and Vietnam. METHODS: Blood samples were collected in the five countries during National Malaria Surveys or during Population Surveys. During Population Surveys samples were characterized for G6PD phenotype using the Fluorescent Spot Test. Samples were then genotyped for a panel of G6PD mutations. RESULTS: G6PD deficiency was found to be common in the region with an overall mean prevalence of deficient or mutated hemizygous males of 14.0%, ranging from a mean 7.3% in Thailand, 8.1% in Lao PDR, 8.9% in Vietnam, 15.8% in Myanmar and 18.8% in Cambodia. Mahidol and Viangchan mutations were the most common and widespread variants found among the nine investigated. CONCLUSIONS: Owing to the high prevalence of G6PD deficiency in the Greater Mekong Subregion, strategies for vivax malaria elimination should include point-of-care G6PD testing (both qualitative and quantitative) to allow safe and wide treatment with 8-aminoquinolines.


Assuntos
Variação Genética , Genótipo , Deficiência de Glucosefosfato Desidrogenase/epidemiologia , Glucosefosfato Desidrogenase/análise , Adolescente , Adulto , Sudeste Asiático/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Prevalência , Adulto Jovem
11.
Korean J Parasitol ; 56(5): 453-461, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30419731

RESUMO

The aim of this study is to delineate 'admixed hybrid' and 'introgressive' Fasciola genotypes present in the Fasciola population in Vietnam. Adult liver flukes collected from ruminants in 18 Provinces were morphologically sorted out by naked eyes for small (S), medium (M) and large (L) body shapes; and human samples (n=14) from patients. Nuclear ribosomal (rDNA) ITS1 and ITS2, and mitochondrial (mtDNA) nad1 markers were used for determination of their genetic status. Total 4,725 worm samples of ruminants were tentatively classified by their size: 6% (n=284) small (S)-, 13% (n=614) medium (M)-, and 81% (n=3,827) large (L)-forms. All the representative (n=120, as 40 each group) and 14 human specimens, possessed maternal mtDNA of only F. gigantica and none of F. hepatica. Paternally, all (100%) of the L-(n=40) and 77.5% (n=31) of the M-flukes had single F. gigantica rDNA indicating 'pure' F. gigantica. A majority (90%, n=36) of the S- and 15% (n=6) of the M-worms had single F. hepatica rDNA, indicating their introgressive; the rest (10%, n=4) of the S- and 7.5% (n=3) of the M-flukes had mixture of both F. gigantica and F. hepatica rDNAs, confirming their admixed hybrid genetic status. Fourteen human samples revealed 9 (64%) of pure F. gigantica, 3 (22%) of introgressive and 2 (14%) of admixed hybrid Fasciola spp. By the present study, it was confirmed that the small worms, which are morphologically identical with F. hepatica, are admixed and/or introgressive hybrids of Fasciola spp., and able to be the pathogens of human fascioliasis.


Assuntos
Fasciola hepatica/isolamento & purificação , Fasciolíase/epidemiologia , Fasciolíase/parasitologia , Ruminantes/parasitologia , Animais , DNA de Helmintos , DNA Mitocondrial , DNA Ribossômico , Fasciola hepatica/anatomia & histologia , Fasciola hepatica/classificação , Fasciola hepatica/genética , Genótipo , Humanos , Vietnã/epidemiologia
12.
Artigo em Inglês | MEDLINE | ID: mdl-28137815

RESUMO

The spread of artemisinin-resistant Plasmodium falciparum compromises the therapeutic efficacy of artemisinin combination therapies (ACTs) and is considered the greatest threat to current global initiatives to control and eliminate malaria. This is particularly relevant in Vietnam, where dihydroartemisinin-piperaquine (DP) is the recommended ACT for P. falciparum infection. The propeller domain gene of K13, a molecular marker of artemisinin resistance, was successfully sequenced in 1,060 P. falciparum isolates collected at 3 malaria hot spots in Vietnam between 2009 and 2016. Eight K13 propeller mutations (Thr474Ile, Tyr493His, Arg539Thr, Ile543Thr, Pro553Leu, Val568Gly, Pro574Leu, and Cys580Tyr), including several that have been validated to be artemisinin resistance markers, were found. The prevalences of K13 mutations were 29% (222/767), 6% (11/188), and 43% (45/105) in the Binh Phuoc, Ninh Thuan, and Gia Lai Provinces of Vietnam, respectively. Cys580Tyr became the dominant genotype in recent years, with 79.1% (34/43) of isolates in Binh Phuoc Province and 63% (17/27) of isolates in Gia Lai Province carrying this mutation. K13 mutations were associated with reduced ring-stage susceptibility to dihydroartemisinin (DHA) in vitro and prolonged parasite clearance in vivo An analysis of haplotypes flanking K13 suggested the presence of multiple strains with the Cys580Tyr mutation rather than a single strain expanding across the three sites.


Assuntos
Doenças Endêmicas , Malária Falciparum/epidemiologia , Mutação , Parasitemia/epidemiologia , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Alelos , Antimaláricos/farmacologia , Artemisininas/farmacologia , Ensaios Clínicos como Assunto , Combinação de Medicamentos , Monitoramento Epidemiológico , Eritrócitos/efeitos dos fármacos , Eritrócitos/parasitologia , Expressão Gênica , Frequência do Gene , Haplótipos , Humanos , Malária Falciparum/tratamento farmacológico , Malária Falciparum/parasitologia , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , Plasmodium falciparum/efeitos dos fármacos , Proteínas de Protozoários/metabolismo , Quinolinas/farmacologia , Vietnã/epidemiologia
13.
Malar J ; 16(1): 17, 2017 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-28061908

RESUMO

BACKGROUND: As part of a targeted malaria elimination project, mass drug administrations (MDAs) were conducted in Vietnam. The impact of MDAs on malaria transmission depends largely on the efficacy of the anti-malarial drug regimen, the malaria epidemiology in the site and the population coverage. To explore why some people participate in MDAs and others do not, a quantitative survey of the villagers' perceptions was undertaken in Vietnam. METHODS: In 2013/2014 MDAs were conducted in a village in Binh Phuoc province and a village in Ninh Thuan province. Within three months of the drug administration, 59 respondents in a village in Binh Phuoc and 79 respondents in a village in Ninh Thuan were randomly selected and interviewed. RESULTS: Comprehension of the purpose of the intervention was of paramount importance for participation in the intervention. Respondents aware that the intervention aims to protect against malaria were significantly more likely to participate than respondents who were unaware of the MDA's purpose. Secondly, how and by whom villagers were informed was critical for participation. There was a strong association between sensitization by an informant such as a member of the local health team with participation in the intervention. CONCLUSIONS: The study suggests several approaches to increase participation in mass drug administration campaigns. Training trustworthy informants to sensitize the study population is critical to maximize village participation in this setting. To achieve high coverage the entire community must understand and agree with the intervention.


Assuntos
Antimaláricos/administração & dosagem , Quimioprevenção/métodos , Transmissão de Doença Infecciosa/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Malária/tratamento farmacológico , Malária/prevenção & controle , Aceitação pelo Paciente de Cuidados de Saúde , Adulto , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , População Rural , Vietnã
14.
Malar J ; 16(1): 27, 2017 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-28086775

RESUMO

BACKGROUND: Artemisinin resistant Plasmodium falciparum has emerged in the countries of the Greater Mekong sub-region posing a serious threat to global malaria elimination efforts. The relationship of artemisinin resistance to treatment failure has been unclear. METHODS: In annual studies conducted in three malaria endemic provinces in the south of Vietnam (Binh Phuoc, Ninh Thuan and Gia Lai) between 2011 and 2015, 489 patients with uncomplicated P. falciparum malaria were enrolled in detailed clinical, parasitological and molecular therapeutic response assessments with 42 days follow up. Patients received the national recommended first-line treatment dihydroartemisinin-piperaquine for three days. RESULTS: Over the 5 years the proportion of patients with detectable parasitaemia on day 3 rose steadily from 38 to 57% (P < 0.001). In Binh Phuoc province, the parasite clearance half-life increased from 3.75 h in 2011 to 6.60 h in 2015 (P < 0.001), while treatment failures rose from 0% in 2012 and 2013, to 7% in 2014 and 26% in 2015 (P < 0.001). Recrudescence was associated with in vitro evidence of artemisinin and piperaquine resistance. In the treatment failures cases of 2015, all 14 parasite isolates carried the C580Y Pfkelch 13 gene, marker of artemisinin resistance and 93% (13/14) of them carried exoE415G mutations, markers of piperaquine resistance. CONCLUSIONS: In the south of Vietnam recent emergence of piperaquine resistant P. falciparum strains has accelerated the reduced response to artemisinin and has led to treatment failure rates of up to 26% to dihydroartemisinin-piperaquine, Vietnam's current first-line ACT. Alternative treatments are urgently needed.


Assuntos
Antimaláricos/farmacologia , Artemisininas/farmacologia , Resistência a Medicamentos , Malária Falciparum/parasitologia , Plasmodium falciparum/efeitos dos fármacos , Quinolinas/farmacologia , Adolescente , Adulto , Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Criança , Pré-Escolar , Doenças Endêmicas , Feminino , Humanos , Incidência , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Masculino , Plasmodium falciparum/isolamento & purificação , Quinolinas/uso terapêutico , Fatores de Tempo , Falha de Tratamento , Vietnã/epidemiologia , Adulto Jovem
16.
Curr Microbiol ; 70(6): 810-5, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25708582

RESUMO

Methanobrevibacter smithii is the main archaea in human, detoxifying molecular hydrogen resulting from anaerobic bacteria fermentations into gaseous methane. Its identification relies on gene sequencing, but no method is available to discriminate among genetic variants of M. smithii. Here, we developed a multispacer sequence typing (MST) for genotyping the genetic variants of M. smithii. Four intergenic spacers recovered from the M. smithii reference genome were PCR amplified and sequenced in three M. smithii reference strains and in a collection of 22 M. smithii isolates from the oral cavity in two individuals and the gut of 10 additional individuals. Sequencing yielded 216 genetic polymorphisms including 89 single nucleotide polymorphisms (41.2 %), 83 insertions (38.4 %), and 44 deletions (20.4 %). Combining these genetic polymorphisms yielded 15 genotypes with an index of discrimination of 0.942 (confidence interval 0.9-0.984; P < 0.05). Five M. smithii isolates made from the oral cavity yielded five different genotypes; seven gut isolates yielded nine different genotypes; genotypes MST5 and MST6 were found both in the oral cavity and the gut. Multiple genotypes were identified in some individuals at the same anatomical site. MST is a sequencing-based method which discriminates several genetic variants within M. smithii. Individuals may harbor several contemporary genetic variants of M. smithii in the oral cavity and gut. MST will allow studying population dynamics of M. smithii and tracing its circulation between individuals and their environment.


Assuntos
DNA Intergênico , Variação Genética , Methanobrevibacter/classificação , Methanobrevibacter/genética , Tipagem Molecular/métodos , Trato Gastrointestinal/microbiologia , Genótipo , Humanos , Methanobrevibacter/isolamento & purificação , Boca/microbiologia
17.
PLoS Negl Trop Dis ; 18(4): e0012014, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38683855

RESUMO

BACKGROUND: Malaria elimination using current tools has stalled in many areas. Ivermectin (IVM) is a broad-antiparasitic drug and mosquitocide and has been proposed as a tool for accelerating progress towards malaria elimination. Under laboratory conditions, IVM has been shown to reduce the survival of adult Anopheles populations that have fed on IVM-treated mammals. Treating cattle with IVM has been proposed as an important contribution to malaria vector management, however, the impacts of IVM in this One Health use case have been untested in field trials in Southeast Asia. METHODS: Through a randomized village-based trial, this study quantified the effect of IVM-treated cattle on anopheline populations in treated vs. untreated villages in Central Vietnam. Local zebu cattle in six rural villages were included in this study. In three villages, cattle were treated with IVM at established veterinary dosages, and in three additional villages cattle were left as untreated controls. For the main study outcome, the mosquito populations in all villages were sampled using cattle-baited traps for six nights before, and six nights after a 2-day IVM-administration (intervention) period. Anopheline species were characterized using taxonomic keys. The impact of the intervention was analyzed using a difference-in-differences (DID) approach with generalized estimating equations (with negative binomial distribution and robust errors). This intervention was powered to detect a 50% reduction in total nightly Anopheles spp. vector catches from cattle-baited traps. Given the unusual diversity in anopheline populations, exploratory analyses examined taxon-level differences in the ecological population diversity. RESULTS: Across the treated villages, 1,112 of 1,523 censused cows (73% overall; range 67% to 83%) were treated with IVM. In both control and treated villages, there was a 30% to 40% decrease in total anophelines captured in the post-intervention period as compared to the pre-intervention period. In the control villages, there were 1,873 captured pre-intervention and 1,079 captured during the post-intervention period. In the treated villages, there were 1,594 captured pre-intervention, and 1,101 captured during the post-intervention period. The difference in differences model analysis comparing total captures between arms was not statistically significant (p = 0.61). Secondary outcomes of vector population diversity found that in three villages (one control and two treatment) Brillouin's index increased, and in three villages (two control and one treatment) Brillouin's index decreased. When examining biodiversity by trapping-night, there were no clear trends in treated or untreated vector populations. Additionally, there were no clear trends when examining the components of biodiversity: richness and evenness. CONCLUSIONS: The ability of this study to quantify the impacts of IVM treatment was limited due to unexpectedly large spatiotemporal variability in trapping rates; an area-wide decrease in trapping counts across all six villages post-intervention; and potential spillover effects. However, this study provides important data to directly inform future studies in the GMS and beyond for IVM-based vector control.


Assuntos
Anopheles , Inseticidas , Ivermectina , Malária , Mosquitos Vetores , Animais , Ivermectina/farmacologia , Bovinos , Vietnã , Anopheles/efeitos dos fármacos , Malária/prevenção & controle , Malária/transmissão , Mosquitos Vetores/efeitos dos fármacos , Inseticidas/farmacologia , Humanos , Feminino , Controle de Mosquitos/métodos
20.
Indian J Otolaryngol Head Neck Surg ; 75(4): 2850-2855, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37974720

RESUMO

Aims: The objective of this study is to assess the effectiveness of the combined middle and inferior meatal antrostomy (MIMA) in management of patients with maxillary fungal sinusitis. Material and Methods: Design: retrospective cross sectional study. Setting and subjects: From September 2018 to March 2021, fifty-five patients with non-invasive maxillary fungal sinusitis, who underwent transnasal endoscopic combined MIMA. Methods: The study compared patients' pre- and post-operative subjective symptoms, including nasal obstruction, discharge, facial pain or pressure, halitosis, anosmia, and other non-specific symptoms. Endoscopic characteristics of recurrent fungal maxillary sinusitis and postoperative complications were also observed. Closure of the IMA site was evaluated at three and six months post-surgery and patients were categorized into three groups based on closure degree. Results: All clinical symptoms, including nasal discharge, nasal obstruction, nasal pruritus, anosmia, halitosis, sneezing, facial pain, ophthalmic and otologic symptoms, were resolved over six months after combined MIMA in majority of cases (94 - 100%). After three and six months, the postoperative endoscopic evaluation revealed recurrent fungal maxillary sinusitis in 1.8% and 5.4% of cases, respectively. Partial stenosis of the inferior antrostomy was observed in 7.2% and 16% of cases, while complete stenosis was noted in 3.6% and 7.2% of cases after three months and six months. Conclusions: The combined MIMA is effective and has better outcomes than the medial meatal antrostomy approach alone without additional operative time. Supplementary Information: The online version contains supplementary material available at 10.1007/s12070-023-03863-6.

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