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1.
Emerg Infect Dis ; 29(6): 1280-1283, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37209696

RESUMO

Microscopy of mummified visceral tissue from a Medici family member in Italy identified a potential blood vessel containing erythrocytes. Giemsa staining, atomic force microscopy, and immunohistochemistry confirmed Plasmodium falciparum inside those erythrocytes. Our results indicate an ancient Mediterranean presence of P. falciparum, which remains responsible for most malaria deaths in Africa.


Assuntos
Malária Falciparum , Malária , Humanos , Malária/epidemiologia , Malária Falciparum/epidemiologia , Plasmodium falciparum , Microscopia/métodos , Itália/epidemiologia
2.
Sex Transm Infect ; 99(5): 330-336, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36396173

RESUMO

OBJECTIVE: The available epidemiological and clinical evidence from the currently ongoing monkeypox (MPX) outbreak in non-endemic areas suggests an important factor of sexual transmission. However, limited information on the behaviour and experiences of individuals with an MPX infection has to date been provided. We aimed to describe the initial phase of the MPX outbreak in Belgium, and to provide a more in-depth description of sexual behaviour and transmission contexts. METHODS: We used routine national surveillance data of 139 confirmed MPX cases with date of symptom onset until 19 June 2022, complemented with 12 semistructured interviews conducted with a subsample of these cases. RESULTS: Sexualised environments, including large festivals and cruising venues for gay men, were the suspected exposure setting for the majority of the cases in the early outbreak phase. In-depth narratives of sexual behaviour support the hypothesis of MPX transmission through close physical contact during sex. Despite awareness of the ongoing MPX outbreak, low self-perceived risk of MPX acquisition and confusing initial signs and symptoms for other STIs or skin conditions delayed early detection of an MPX infection. In addition, we describe relevant contextual factors beyond individual behaviour, related to sexual networks, interpersonal interactions and health systems. Some of these factors may complicate early MPX detection and control efforts. CONCLUSION: Our results highlight the role of sexual contact and networks in the transmission of MPX during the early phase of the outbreak in Belgium. Risk communication messages should consistently and transparently state the predominant sexual transmission potential of MPX virus, and prevention and control measures must be adapted to reflect multilevel factors contributing to MPX transmission risk.


Assuntos
Surtos de Doenças , Monkeypox virus , Masculino , Humanos , Bélgica/epidemiologia , Comportamento Sexual , Comunicação
3.
Euro Surveill ; 28(7)2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36795501

RESUMO

While mpox was well characterised during the 2022 global Clade IIb outbreak, little is known about persistent morbidity. We present interim results of a prospective cohort study of 95 mpox patients assessed 3-20 weeks post-symptom onset. Two-thirds of participants had residual morbidity, including 25 with persistent anorectal and 18 with genital symptoms. Loss of physical fitness, new-onset/worsened fatigue and mental health problems were reported in 36, 19 and 11 patients, respectively. These findings require attention by healthcare providers.


Assuntos
Surtos de Doenças , Mpox , Humanos , Bélgica/epidemiologia , Seguimentos , Morbidade , Estudos Prospectivos , Mpox/epidemiologia , Mpox/patologia
4.
Euro Surveill ; 27(48)2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36695462

RESUMO

Vaccination is important in containing the 2022 mpox (formerly monkeypox) epidemic. We describe five Belgian patients with localised severe symptoms of proctitis and penile oedema, occurring between 4 and 35 days after post-exposure preventive vaccination or after one- or two-dose off-label pre-exposure preventive vaccination with MVA-BN vaccine. Genome sequencing did not reveal evidence for immune escape variants. Healthcare workers and those at risk should be aware of possible infections occurring shortly after vaccination and the need for other preventive measures.


Assuntos
Mpox , Vacina Antivariólica , Humanos , Bélgica/epidemiologia , Mpox/prevenção & controle , Vacina Antivariólica/efeitos adversos , Vacinação/efeitos adversos
5.
Malar J ; 17(1): 251, 2018 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-29976228

RESUMO

BACKGROUND: The spread of SP resistance may compromise the effectiveness of intermittent preventive treatment of malaria in pregnancy (MiP) with sulfadoxine-pyrimethamine (IPTp-SP) across Africa. However, there is no recommended alternative medicine for IPTp or alternative strategy for prevention of MiP. This poses problems for the prevention of MiP. This study investigated, whether screening with a rapid diagnostic test for malaria at routine antenatal clinic attendances and treatment of only those who are positive (intermittent screening and treatment) with artemether-lumefantrine is as effective and safe as IPTp-SP in pregnant women. METHODS: During antenatal clinic sessions at the General Hospital Calabar, Nigeria, held between October 2013 and November 2014, 459 pregnant women were randomized into either the current standard IPTp-SP or intermittent screening and treatment with artemether-lumefantrine (ISTp-AL). All women received a long-lasting insecticide-treated net at enrolment. Study women had a maximum of four scheduled visits following enrolment. Haemoglobin concentration and peripheral parasitaemia were assessed in the third trimester (36-40 weeks of gestation). Birth weight was documented at delivery or within a week for babies delivered at home. RESULTS: In the third trimester, the overall prevalence of severe anaemia (Hb < 8 g/dl) and moderate (8-10.9 g/dl) anaemia was 0.8 and 27.7%, respectively, and was similar in both treatment groups (p = 0.204). The risk of third-trimester severe anaemia did not differ significantly between both treatment arms (risk difference - 1.75% [95% CI - 4.16 to 0.66]) although the sample was underpowered for this outcome due to several participants being unavailable to give a blood sample. The risk of third-trimester maternal parasitaemia was significantly lower in the ISTp-AL arm (RD - 3.96% [95% CI - 7.76 to - 0.16]). The risk of low birthweight was significantly lower in the ISTp-AL arm after controlling for maternal age, gravidity and baseline parasitaemia (risk difference - 1.53% [95% CI - 1.54 to - 1.15]). Women in the ISTp-AL arm complained of fever more frequently compared to women in the IPTp-SP arm (p = 0.022). CONCLUSIONS: The trial results suggest that in an area of high malaria transmission with moderate sulfadoxine-pyrimethamine resistance, ISTp with artemether-lumefantrine may be an effective strategy for controlling malaria in pregnancy. Trial registration PACTR, PACTR201308000543272. Registered 29 April 2013, http://www.pactr.org/ATMWeb/appmanager/atm/atmregistry?dar=true&tNo=PACTR201308000543272.


Assuntos
Antimaláricos/uso terapêutico , Combinação Arteméter e Lumefantrina/uso terapêutico , Malária Falciparum/prevenção & controle , Programas de Rastreamento/estatística & dados numéricos , Parasitemia/tratamento farmacológico , Complicações Parasitárias na Gravidez/prevenção & controle , Pirimetamina/uso terapêutico , Sulfadoxina/uso terapêutico , Adolescente , Adulto , Quimioprevenção , Combinação de Medicamentos , Feminino , Humanos , Incidência , Malária Falciparum/parasitologia , Nigéria/epidemiologia , Parasitemia/parasitologia , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/fisiologia , Gravidez , Prevalência , Adulto Jovem
6.
Malar J ; 17(1): 358, 2018 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-30314477

RESUMO

BACKGROUND: The study aimed to gain first data on the prevalence of G6PD enzyme deficiency measured by spectrophotometry and associated genetic variants in Jimma and surroundings, Ethiopia. The area is a Plasmodium vivax endemic region, but 8-aminoquinolines such as primaquine are not recommended as G6PD testing is not available. METHODS: Healthy volunteers were recruited at Jimma University, Ethiopia. Enzyme activity was tested by spectrophotometry at the University of Ulm, Germany. A G6PD RDT (Binax NOW® G6PD, Alere, USA) was additionally performed. The G6PD gene was analysed for polymorphisms in a sub-population. Tests for haemoglobinopathies and the presence of malaria parasites were conducted. RESULTS: No severe or moderate (cut-off 60%) G6PD deficiency was found in 206 volunteers. Median male activity was 6.1 U/g Hb. Eleven participants (5.4%) showed activities between 70 and 80%. No haemoglobinopathy was detected. None of the subjects showed asymptomatic parasitaemia. One G6PD-A+ variant (A376G) and one new non-synonymous mutation (G445A) were found. CONCLUSIONS: As the prevalence of G6PD deficiency seems low in this area, the use of 8-aminoquinolines should be encouraged. However, reliable G6PD testing methods have to be implemented and safe cut-off levels need to be defined.


Assuntos
Variação Genética , Deficiência de Glucosefosfato Desidrogenase/epidemiologia , Glucosefosfato Desidrogenase/genética , Adulto , Antimaláricos/uso terapêutico , Etiópia , Feminino , Deficiência de Glucosefosfato Desidrogenase/genética , Humanos , Masculino , Primaquina/uso terapêutico , Espectrofotometria , Adulto Jovem
7.
Malar J ; 17(1): 245, 2018 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-29940968

RESUMO

BACKGROUND: A marked decline in malaria morbidity and mortality has been reported after the introduction of artemisinin-based combination therapy (ACT) in high malaria prevalence countries in Africa. Data on the impact of ACT and on the prevalence of malaria has so far been scarce for Southwest Tanzania. METHODS: Between 2005 and 2011, a large general population cohort in the Mbeya Region in the south-west of Tanzania has been surveyed within the EMINI-study (Evaluation and Monitoring of the Impact of New Interventions). Participants were examined once per year, including rapid diagnostic testing for malaria. ACT was introduced in the region according to national guidelines in the time period 2006/2007, replacing sulfadoxine/pyrimethamine as first-line therapy. In four study sites, 6773 individuals who participated in the first two of three consecutive survey visits in the period from 2006 to 2009 were included in this analysis. The prevalence of Plasmodium infection prior to and after the introduction of ACT was compared by logistic regression, with consideration of climatic variability, age, sex, socio-economic status and bed net use as potential confounders. RESULTS: A significant reduction over time in the prevalence of Plasmodium falciparum infection from 2.5 to 0.3% was shown across the four study sites. The decline was not explained by other factors included in the analysis, therefore, the decline over time most likely reflects the impact of introduction of ACT in the study area. CONCLUSIONS: The longitudinal study showed a significant and relevant decline in the prevalence of P. falciparum infection after introduction of ACT, which could not be explained by potential confounders. The data suggests that artemisinin-based combinations are not only an effective instrument for reduction of immediate morbidity and mortality, but also for reduction of transmission rates.


Assuntos
Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Malária Falciparum/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Combinação de Medicamentos , Feminino , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Malária Falciparum/prevenção & controle , Masculino , Pessoa de Meia-Idade , Prevalência , Tanzânia/epidemiologia , Adulto Jovem
8.
Parasitol Res ; 117(3): 801-807, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29332155

RESUMO

Sulfadoxine-pyrimethamine (SP) is the recommended drug for intermittent preventive treatment of malaria in pregnancy in most of sub-Saharan Africa. Resistance to SP is related to mutations in the dhfr and dhps gene of Plasmodium falciparum. This study determined the prevalence of Pfdhfr and Pfdhps polymorphisms found in asymptomatic pregnant women attending antenatal care in Calabar, Nigeria. From October 2013 to November 2014, asymptomatic pregnant women attending antenatal care clinics were enrolled after obtaining informed consent. Malaria diagnosis testing was done using thick and thin smears. Dried blood spot filter papers were collected. Parasite DNA was extracted from the filter papers using a chelex extraction. Extraction was followed by nested PCR and restriction enzyme digestion. P. falciparum infection was detected by microscopy in 7% (32/459) participants. Twenty-eight P. falciparum isolates were successfully genotyped. In the Pfdhfr gene, the triple mutation was almost fixed; S108N mutation was (100%), N51I (93%) and C59R mutations (93%), whereas the I164L mutation was absent. The prevalence of Pfdhps S436A, A437G, A581G and A613S mutations was 82.1% (23/28), 96.4% (27/28), 71.4% (20/28) and 71.4% (20/28) respectively. The K540E mutation was absent. The prevalence of the Pfdhfr triple mutation IRNI was 92.9% (26/28). The efficacy of SP as IPTp in Southeast Nigeria may be severely threatened. The continuous monitoring of SP molecular markers of resistance is required to assess thresholds. The evaluation of alternative preventive treatment strategies and drug options for preventing malaria in pregnancy may be necessary.


Assuntos
Malária Falciparum/parasitologia , Mutação , Plasmodium falciparum/genética , Complicações Parasitárias na Gravidez/parasitologia , Proteínas de Protozoários/genética , Tetra-Hidrofolato Desidrogenase/genética , Adulto , Antimaláricos/administração & dosagem , Combinação de Medicamentos , Feminino , Genótipo , Humanos , Taxa de Mutação , Nigéria , Plasmodium falciparum/enzimologia , Plasmodium falciparum/isolamento & purificação , Reação em Cadeia da Polimerase , Polimorfismo Genético , Gravidez , Pirimetamina/administração & dosagem , Sulfadoxina/administração & dosagem
9.
J Infect Dis ; 211(5): 689-97, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25267980

RESUMO

BACKGROUND: Methylene blue (MB) has been shown to be safe and effective against falciparum malaria in Africa and to have pronounced gametocytocidal properties. METHODS: Three days of treatment with artesunate (AS)-amodiaquine (AQ) combined with MB was compared with AS-AQ treatment in a randomized controlled phase IIb study; the study included 221 children aged 6-59 months with uncomplicated falciparum malaria in Burkina Faso. The primary end point was gametocyte prevalence during follow-up, as determined by microscopy and real-time quantitative nucleic acid sequence-based amplification (QT-NASBA). RESULTS: The gametocyte prevalence of Plasmodium falciparum at baseline was 3.6% (microscopy) and 97% (QT-NASBA). It was significantly lower in the AS-AQ-MB than in the AS-AQ group on day 7 of follow-up (microscopy, 1.2% vs 8.9% [P < .05]; QT-NASBA, 36.7% vs 63.3% [P < .001]). Hemoglobin values were significantly lower in the AS-AQ-MB group than in the AS-AQ group at days 2 and 7 of follow-up. Vomiting of the study medication occurred significantly more frequently in the AS-AQ-MB group. CONCLUSIONS: The combination of MB with an artemisinin-based combination therapy has been confirmed to be effective against the gametocytes of P. falciparum. MB-based combinations need to be compared with primaquine-based combinations, preferably using MB in an improved pediatric formulation. Clinical Trials Registration: NCT01407887.


Assuntos
Amodiaquina/uso terapêutico , Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Malária Falciparum/tratamento farmacológico , Azul de Metileno/uso terapêutico , Amodiaquina/efeitos adversos , Antimaláricos/efeitos adversos , Artemisininas/efeitos adversos , Artesunato , Burkina Faso , Pré-Escolar , Quimioterapia Combinada/métodos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Feminino , Humanos , Lactente , Masculino , Azul de Metileno/efeitos adversos , Microscopia , Plasmodium falciparum/isolamento & purificação , Reação em Cadeia da Polimerase , Resultado do Tratamento
10.
Malar J ; 14: 208, 2015 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-25986047

RESUMO

BACKGROUND: Drug resistance is one of the main reasons of anti-malarial treatment failures and impedes malaria containment strategies. As single nucleotide polymorphisms (SNPs) have been found to correlate with anti-malarial drug resistance, the surveillance strategy includes continuous monitoring of known molecular markers and detection of new mutation patterns. With the introduction of artemisinin-based combination therapy, selection of specific patterns has been observed worldwide. METHODS: From March to June 2013, whole blood was collected on filter paper from microscopically malaria positive patients in Jimma zone (District), southwestern Ethiopia. Plasmodium falciparum, Plasmodium vivax and mixed infections were included. SNPs were investigated by conventional or real-time PCR, restriction fragment length pattern analysis or sequencing. Results were compared to molecular patterns from Ethiopian isolates in 2004, 2006 and 2008/9. RESULTS: Plasmodium falciparum, P. vivax, and mixed infections were molecularly confirmed in 177, 80, and 14 samples, respectively. In P. falciparum, mutations in the pfcrt, pfmdr 1and pfATP 6 (SERCA) gene were investigated. Whereas the mutation in the pfcrt gene at codon 76 K was still found in 95.6% of all samples, the pfmdr 1 86 T mutation fell to 1.2% (2/163) in 2013 compared to 9% in 2008/9 and 86% in 2006 (P<0.001). The pfmdr 1 184 F mutation dominated with 100.0% (172/172) in 2013. Sequencing of the recently reported PF3D7_1343700 kelch propeller domain showed no mutation at codon 476. First sequencing data of the pvmdr 1 gene from Jimma region revealed a prevalence of the mutations 976 F and 1076 L in 72.7% (16/23) and 100.0% (19/19) of the isolates, respectively. CONCLUSION: Since the introduction of artemether-lumefantrine (AL) in Jimma, Ethiopia, in 2006, the prevalence of certain SNPs associated with AL use has increased. Markers for chloroquine resistance in P. vivax were highly frequent. Continuous molecular and clinical surveillance are of paramount importance.


Assuntos
Antimaláricos/farmacologia , Resistência a Medicamentos , Malária Falciparum/epidemiologia , Malária Vivax/epidemiologia , Plasmodium falciparum/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Combinação Arteméter e Lumefantrina , Artemisininas/farmacologia , Biomarcadores/sangue , Criança , Pré-Escolar , Combinação de Medicamentos , Etanolaminas/farmacologia , Etiópia/epidemiologia , Feminino , Fluorenos/farmacologia , Humanos , Lactente , Malária Falciparum/parasitologia , Malária Falciparum/prevenção & controle , Malária Vivax/parasitologia , Malária Vivax/prevenção & controle , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/efeitos dos fármacos , Plasmodium vivax/efeitos dos fármacos , Prevalência , Proteínas de Protozoários/genética , Reação em Cadeia da Polimerase em Tempo Real , Estações do Ano , Adulto Jovem
11.
Malar J ; 13: 422, 2014 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-25367021

RESUMO

During the last two decades human infections with Plasmodium knowlesi are increasingly diagnosed in South East Asia and have also been reported in travellers. A severe case of imported P. knowlesi infection in a 73-year old German is presented, who had been travelling through Myanmar and Thailand for three weeks. Microscopy showed a parasitaemia of 3% and different parasite stages including band-forms resembling Plasmodium malariae. Due to the clinical picture of severe malaria and the microscopical aspect (combination of parasites resembling P. malariae and Plasmodium falciparum), P. knowlesi was suspected. The patient was treated with intravenous quinine; he was put on mechanical ventilation and catecholamines due to cardiorespiratory failure. Parasitaemia was cleared rapidly but renal function deteriorated resulting in intermittent haemodialysis. The patient was hospitalized for six weeks but he recovered completely without any physical sequelae. Plasmodium knowlesi mono-infection was confirmed by molecular methods later on.Plasmodium knowlesi infection has to be taken into account in feverish travellers returning from Thailand/Myanmar. Moreover this species can cause life-threatening or even lethal complications. Accordingly severe P. knowlesi infection should be treated like severe P. falciparum infections.


Assuntos
Malária , Insuficiência de Múltiplos Órgãos , Plasmodium knowlesi , Idoso , Alemanha , Humanos , Masculino , Tailândia , Viagem
12.
Malar J ; 13: 155, 2014 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-24758172

RESUMO

BACKGROUND: Malaria has been shown to change blood counts. Recently, a few studies have investigated the alteration of the peripheral blood monocyte-to-lymphocyte count ratio (MLCR) and the neutrophil-to-lymphocyte count ratio (NLCR) during infection with Plasmodium falciparum. Based on these findings this study investigates the predictive values of blood count alterations during malaria across different sub-populations. METHODS: Cases and controls admitted to the Department of Infectious Diseases and Tropical Medicine from January 2000 through December 2010 were included in this comparative analysis. Blood count values and other variables at admission controlled for age, gender and immune status were statistically investigated. RESULTS: The study population comprised 210 malaria patients, infected with P. falciparum (68%), Plasmodium vivax (21%), Plasmodium ovale (7%) and Plasmodium malariae (4%), and 210 controls. A positive correlation of parasite density with NLCR and neutrophil counts, and a negative correlation of parasite density with thrombocyte, leucocyte and lymphocyte counts were found. An interaction with semi-immunity was observed; ratios were significantly different in semi-immune compared to non-immune patients (P <0.001).The MLCR discriminated best between malaria cases and controls (AUC = 0.691; AUC = 0.741 in non-immune travellers), whereas the NLCR better predicted severe malaria, especially in semi-immune patients (AUC = 0.788). CONCLUSION: Malaria causes typical but non-specific alterations of the differential blood count. The predictive value of the ratios was fair but limited. However, these changes were less pronounced in patients with semi-immunity. The ratios might constitute easily applicable surrogate biomarkers for immunity.


Assuntos
Contagem de Leucócitos/métodos , Malária/epidemiologia , Malária/imunologia , Plasmodium/fisiologia , Adolescente , Adulto , Idoso , Biomarcadores , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Alemanha/epidemiologia , Humanos , Lactente , Malária/parasitologia , Masculino , Pessoa de Meia-Idade , Parasitemia/epidemiologia , Parasitemia/imunologia , Parasitemia/patologia , Valor Preditivo dos Testes , Viagem , Adulto Jovem
13.
Korean J Parasitol ; 52(6): 639-44, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25548415

RESUMO

Congenital malaria is assumed to be a risk factor for infant morbidity and mortality in endemic areas like Maumere, Indonesia. Infected infants are susceptible to its impact such as premature labor, low birth weight, anemia, and other unspecified symptoms. The aim of this study was to investigate the prevalence of congenital malaria and the influence of mother-infant paired parasite densities on the clinical outcome of the newborns at TC Hillers Hospital, Maumere. An analytical cross sectional study was carried out in newborns which showed criteria associated with congenital malaria. A thick and thin blood smear confirmed by nested PCR was performed in both mothers and infants. The association of congenital malaria with the newborn's health status was then assessed. From 112 mother-infant pairs included in this study, 92 were evaluated further. Thirty-nine infants (42.4%) were found to be infected and half of them were asymptomatic. Infected newborns had a 4.7 times higher risk in developing anemia compared to uninfected newborns (95% CI, 1.3-17.1). The hemoglobin level, erythrocyte amount, and hematocrit level were affected by the infants' parasite densities (P<0.05). Focusing on newborns at risk of congenital malaria, the prevalence is almost 3 times higher than in an unselected collective. Low birth weight, anemia, and pre-term birth were the most common features. Anemia seems to be significantly influenced by infant parasite densities but not by maternal parasitemia.


Assuntos
Anemia/etiologia , Recém-Nascido de Baixo Peso , Malária/congênito , Malária/epidemiologia , Sangue/parasitologia , Estudos Transversais , Feminino , Humanos , Indonésia/epidemiologia , Recém-Nascido , Malária/patologia , Masculino , Microscopia , Reação em Cadeia da Polimerase , Prevalência
14.
Malar J ; 12: 80, 2013 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-23446319

RESUMO

BACKGROUND: The large polymorphic protein PfEMP1 is encoded by the var gene family. PfEMP1 has been shown to play an important role as cytoadherence ligand on the surface of infected erythrocytes and thereby contributes to the distinct pathogenesis of malaria. The study explored the diversity of the DBL1α and DBL2ß-C2 domains of the protein from Indonesian Plasmodium falciparum field isolates. METHODS: Samples of patients with severe and uncomplicated malaria from two different malaria-endemic areas in Indonesia were collected and DNA directly extracted. Dried blood on filter paper was prepared for RNA extraction. PCR amplicons were either cloned and subsequently sequenced or directly sequenced for analysis on nucleotide and amino acid level. Recently published as well as self-designed primers were used for amplification. RESULTS: Blood from eight patients was finally used for analysis. Seventy-one different sequences out of over 500 DBL1α sequenced clones were observed, resulting in an average of 8.9 different DBL1α sequences per isolate. The average DBL1α sequence similarity within isolates was similar to between isolates. Phylogenetic analysis demonstrated no clustering of sequences regarding strain or geographical origin. The DBL1α sequences were analysed by distribution of semi-conserved features (cysteine/PoLV1-4 grouping) and classified into six sequence groups. The DBL1α cys2 type was observed in all expressed sequences in vivo. Expression of certain DBL sequences implied potential involvement in the pathogenesis. As expected, the DBL2ß-C2 domains showed high to moderate homology among each other. CONCLUSION: The DBL1α domains of PfEMP1 from clinical Indonesian isolates showed high divergence among same isolates and some similarities with other Asia-Pacific strains. Further investigations of important var gene domains with a larger sample size are required to confirm with statistical significance observed associations with severe malaria in Indonesian samples.


Assuntos
Variação Genética , Plasmodium falciparum/classificação , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Adulto , Análise por Conglomerados , DNA de Protozoário/química , DNA de Protozoário/genética , Feminino , Genótipo , Humanos , Indonésia , Malária Falciparum/parasitologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Filogenia , Plasmodium falciparum/isolamento & purificação , Análise de Sequência de DNA , Adulto Jovem
15.
Malar J ; 12: 438, 2013 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-24305630

RESUMO

BACKGROUND: For future eradication strategies of malaria it is important to control the transmission of gametocytes from humans to the anopheline vector which causes the spread of the disease. Sensitive, non-invasive methods to detect gametocytes under field conditions can play a role in monitoring transmission potential. METHODS: Microscopically Plasmodium falciparum-positive patients from Jimma, Ethiopia donated finger-prick blood, venous blood, saliva, oral mucosa and urine samples that were spotted on filter paper or swabs. All samples were taken and stored under equal, standardized conditions. RNA was extracted from the filter paper and detected by real-time QT-NASBA. Pfs16-mRNA and Pfs25-mRNA were measured with a time to positivity to detect gametocyte specific mRNA in different gametocyte stages. They were compared to 18S-rRNA, which is expressed in all parasite stages. Results were quantified via a known dilution series of artificial RNA copies. RESULTS: Ninety-six samples of 16 uncomplicated malaria patients were investigated. 10 (66.7%) of the slides showed gametocyte densities between 0.3-2.9 gametocytes/µl. For all RNA-targets, molecular detection in blood samples was most sensitive; finger-prick sampling required significantly smaller amounts of blood than venous blood collection. Detection of asexual 18S-rRNA in saliva and urine showed sensitivities of 80 and 67%, respectively. Non-invasive methods to count gametocytes proved insensitive. Pfs16-mRNA was detectable in 20% of urine samples, sensitivities for other materials were lower. Pfs25-mRNA was not detectable in any sample. CONCLUSIONS: The sensitivity of non-invasively collected material such as urine, saliva or mucosa seems unsuitable for the detection of gametocyte-specific mRNA. Sensitivity in asymptomatic carriers might be generally even lower. Finger-prick testing revealed the highest absolute count of RNA copies per µL, especially for Pfs25-mRNA copies. The method proved to be the most effective and should preferably be applied in future transmission control and eradication plans. A rapid test for gametocyte targets would simplify efforts.


Assuntos
Estágios do Ciclo de Vida/genética , Malária Falciparum/parasitologia , Plasmodium falciparum/isolamento & purificação , Adolescente , Adulto , Idoso , Feminino , Humanos , Estágios do Ciclo de Vida/fisiologia , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/genética , Plasmodium falciparum/metabolismo , Plasmodium falciparum/fisiologia , Proteínas de Protozoários/análise , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , RNA Mensageiro/análise , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA de Protozoário/análise , RNA de Protozoário/genética , RNA de Protozoário/metabolismo , Adulto Jovem
16.
J Travel Med ; 2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37074147

RESUMO

BACKGROUND: The purpose of this exploratory study was to evaluate different accelerated tick-borne encephalitis (TBE) vaccine schedules for last-minute travellers. METHODS: In a single-centre, open-label pilot study, 77 TBE-naïve Belgian soldiers were randomized to one of the following five schedules with FSME-Immun®: group 1 ('classical accelerated' schedule) received one intramuscular (IM) dose at day 0 and day 14, group 2 two IM doses at day 0, group 3 two intradermal (ID) doses at day 0, group 4 two ID doses at day 0 and day 7, group 5 two ID doses at day 0 and day 14. The last dose(s) of the primary vaccination scheme were given after one year: IM (1 dose) or ID (2 doses). TBE virus neutralizing antibodies were measured in a plaque reduction neutralization test (PRNT90 and 50) at day 0, 14, 21, 28, month 3, 6, 12, and 12 + 21 days. Seropositivity was defined as neutralizing antibody titres ≥10. RESULTS: The median age was 19-19.5 years in each group. Median time-to-seropositivity up to day 28 was shortest for PRNT90 in ID-group 4 and for PRNT50 in all ID groups. Seroconversion until day 28 peaked highest for PRNT90 in ID-group 4 (79%) and for PRNT50 in ID-groups 4 and 5 (both 100%). Seropositivity after the last vaccination after 12 months was high in all groups. Previous yellow fever vaccination was reported in 16% and associated with lower GMTs of TBE-specific antibodies at all time points. The vaccine was generally well tolerated. However, mild to moderate local reactions occurred in 73-100% of ID compared to 0-38% of IM vaccinations, persistent discolouration was observed in nine ID vaccinated individuals. CONCLUSION: The accelerated two-visit ID schedules might offer a better immunological alternative to the recommended classical accelerated IM schedule but an aluminium-free vaccine would preferable.

17.
New Microbes New Infect ; 52: 101093, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36874154

RESUMO

Background: The presentation of mpox clade IIb during the 2022 outbreak overlaps with a range of other diseases. Understanding the factors associated with mpox is important for clinical decision making. Methods: We described the characteristics of mpox patients who sought care at Belgian sexual health clinic. Furthermore we compared their characteristics to those of patients with a clinical suspicion of mpox but who tested negative on polymerase chain reaction. Results: Between May 23 and September 20, 2022, 155 patients were diagnosed with mpox, and 51 patients with suspected symptoms tested negative. All mpox patients self-identified as men and 148/155 (95.5%) as gay or bisexual MSM. Systemic symptoms were present in 116/155 (74.8%) patients. All but 10 patients (145/155, 93.5%) presented with skin lesions. Other manifestations were lymphadenopathy (72/155, 46.5%), proctitis (50/155, 32.3%), urethritis (12/155, 7.7%), tonsillitis (2/155, 1.3%). Complications involved bacterial skin infection (13/155, 8.4%) and penile oedema with or without paraphimosis (4/155, 2.6%). In multivariable logistic regression models, the presence of lymphadenopathy (OR 3.79 95% CI 1.44-11.49), skin lesions (OR 4.35 95% CI 1.15-17.57) and proctitis (OR 9.41 95% CI 2.72-47.07) were associated with the diagnosis of mpox. There were no associations with age, HIV status, childhood smallpox vaccination, number of sexual partners and international travel. Conclusions: The presence of proctitis, lymphadenopathies and skin lesions should increase clinical suspicion of mpox in patients with compatible symptoms.

18.
J Clin Virol ; 159: 105372, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36608620

RESUMO

BACKGROUND: Mpox (formerly monkeypox) is a viral disease caused by the mpox virus (MPXV), endemic in Central and West Africa and currently causing a global outbreak of international concern. Much remains unknown about sample types most suited for mpox laboratory diagnosis. While it is established that high viral loads can be found in active skin lesions (currently the recommended mpox laboratory confirmation specimen type), WHO mpox testing guidelines encourage the use of oropharyngeal swabs as an additional sample type for mpox diagnosis and suggest investigating the value of other specimens like blood samples. OBJECTIVE: In this study, we verified the value of select alternative specimen types for mpox laboratory confirmation. METHODS: We included 25 patients with MPXV-confirmed skin lesions to compare diagnostic sensitivity of MPXV PCR testing on EDTA plasma and two upper respiratory specimens: oropharyngeal swabs and saliva. RESULTS: In our patient cohort with MPXV-confirmed skin lesions, diagnostic sensitivity of MPXV PCR was 80% in EDTA plasma, 64% in oropharyngeal swabs, and 88% in saliva. MPXV viral loads were significantly higher in saliva compared to oropharyngeal swabs and EDTA plasma. DISCUSSION: The WHO recommendation to collect oropharyngeal swabs as an additional specimen for mpox diagnosis might need to be revised to include saliva wherever feasible. We suggest investigating saliva as a diagnostic specimen in the absence of active skin lesions or during the phase preceding skin manifestations. Moreover, the relatively high MPXV DNA content of saliva warrants elucidating its potential role in disease transmission.


Assuntos
Monkeypox virus , Mpox , Humanos , Monkeypox virus/genética , Mpox/diagnóstico , Ácido Edético , Reação em Cadeia da Polimerase , Técnicas de Amplificação de Ácido Nucleico
19.
Malar J ; 11: 240, 2012 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-22824059

RESUMO

BACKGROUND: In Jimma Zone, Ethiopia, the first-line treatment of uncomplicated falciparum malaria has been changed from sulphadoxine-pyrimethamine (SP) to artemether-lumefantrine (AL) in 2006. The objective of this study was to assess the effectiveness of AL in Jimma Zone two to three years after its broad introduction. METHODS: An open-label, single-arm, 42-day study of AL against falciparum malaria was conducted in four areas with moderate transmission in Jimma Zone between November 2008 and January 2009 and between August and December 2009. Patients (one-81 years) with uncomplicated Plasmodium falciparum mono-infection were consecutively enrolled. Follow-up visits were at day 2, 3, 7, 28 and 42 or any other day if symptoms reoccurred. Primary and secondary endpoints were PCR-corrected and uncorrected cure rates (molecular differentiation between recrudescence and re-infection) on days 28 and 42. Other secondary endpoints were gametocytaemia at day 7 and day 28, parasitaemia at day 2 and 3, and re-infection rates at day 28 and day 42. RESULTS: Of 348 enrolled patients, 313 and 301 completed follow-up at day 28 and at day 42, respectively. No early treatment failure occurred. For per protocol analysis, PCR-uncorrected cure rates at day 28 and 42 were 99.1% (95% CI 98.0-100.0) and 91.1% (95% CI 87.9-94.3), respectively. PCR-corrected cure rates at day 28 and 42 were 99.4% (95% CI 98.5-100.0) and 94.7% (95% CI 92.2-97.2), respectively. PCR-corrected cure rate at day 42 for children ≤ 5 years was 90.6% (95% CI 82.4-98.7) only. Adverse events were in general mild to moderate. Incidence of new infections was 3.4% during 42 days, no new infections with Plasmodium vivax were observed. Microscopically detected gametocytaemia was reduced by 80% between day 0 and day 7. CONCLUSION: In general, AL was effective and well tolerated in Jimma Zone, Ethiopia. However, the PCR-corrected recrudescence rate per-protocol at day 42 for children ≤ 5 years was 9.4%. Therefore, further development should be monitored on a regular basis as recommended by WHO.


Assuntos
Antimaláricos/administração & dosagem , Artemisininas/administração & dosagem , Etanolaminas/administração & dosagem , Fluorenos/administração & dosagem , Malária Falciparum/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antimaláricos/efeitos adversos , Combinação Arteméter e Lumefantrina , Artemisininas/efeitos adversos , Criança , Pré-Escolar , Combinação de Medicamentos , Etanolaminas/efeitos adversos , Etiópia , Feminino , Fluorenos/efeitos adversos , Humanos , Lactente , Malária Falciparum/parasitologia , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , Reação em Cadeia da Polimerase , Resultado do Tratamento , Adulto Jovem
20.
Malar J ; 11: 138, 2012 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-22545954

RESUMO

BACKGROUND: Real-time quantitative nucleic acid sequence-based amplification (QT-NASBA) is a sensitive method for detection of sub-microscopic gametocytaemia by measuring gametocyte-specific mRNA. Performing analysis on fresh whole blood samples is often not feasible in remote and resource-poor areas. Convenient methods for sample storage and transport are urgently needed. METHODS: Real-time QT-NASBA was performed on whole blood spiked with a dilution series of purified in-vitro cultivated gametocytes. The blood was either freshly processed or spotted on filter papers. Gametocyte detection sensitivity for QT-NASBA was determined and controlled by microscopy. Dried blood spot (DBS) samples were subjected to five different storage conditions and the loss of sensitivity over time was investigated. A formula to approximate the loss of Pfs25-mRNA due to different storage conditions and time was developed. RESULTS: Pfs25-mRNA was measured in time to positivity (TTP) and correlated well with the microscopic counts and the theoretical concentrations of the dilution series. TTP results constantly indicated higher amounts of RNA in filter paper samples extracted after 24 hours than in immediately extracted fresh blood. Among investigated storage conditions freezing at -20°C performed best with 98.7% of the Pfs25-mRNA still detectable at day 28 compared to fresh blood samples. After 92 days, the RNA detection rate was only slightly decreased to 92.9%. Samples stored at 37°C showed most decay with only 64.5% of Pfs25-mRNA detectable after one month. The calculated theoretical detection limit for 24 h-old DBS filter paper samples was 0.0095 (95% CI: 0.0025 to 0.0380) per µl. CONCLUSIONS: The results suggest that the application of DBS filter papers for quantification of Plasmodium falciparum gametocytes with real-time QT-NASBA is practical and recommendable. This method proved sensitive enough for detection of sub-microscopic densities even after prolonged storage. Decay rates can be predicted for different storage conditions as well as durations.


Assuntos
Sangue/parasitologia , Malária Falciparum/diagnóstico , Malária Falciparum/parasitologia , Proteínas de Protozoários/genética , Estabilidade de RNA , RNA Mensageiro/isolamento & purificação , Manejo de Espécimes/métodos , Humanos , Técnicas de Diagnóstico Molecular/métodos , RNA Mensageiro/genética , Replicação de Sequência Autossustentável/métodos , Sensibilidade e Especificidade , Fatores de Tempo
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