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1.
Malar J ; 21(1): 23, 2022 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-35073934

RESUMO

BACKGROUND: Surveillance programmes often use malaria rapid diagnostic tests (RDTs) to determine the proportion of the population carrying parasites in their peripheral blood to assess the malaria transmission intensity. Despite an increasing number of reports on false-negative and false-positive RDT results, there is a lack of systematic quality control activities for RDTs deployed in malaria surveillance programmes. METHODS: The diagnostic performance of field-deployed RDTs used for malaria surveys was assessed by retrospective molecular analysis of the blood retained on the tests. RESULTS: Of the 2865 RDTs that were collected in 2018 on Bioko Island and analysed in this study, 4.7% had a false-negative result. These false-negative RDTs were associated with low parasite density infections. In 16.6% of analysed samples, masked pfhrp2 and pfhrp3 gene deletions were identified, in which at least one Plasmodium falciparum strain carried a gene deletion. Among all positive RDTs analysed, 28.4% were tested negative by qPCR and therefore considered to be false-positive. Analysing the questionnaire data collected from the participants, this high proportion of false-positive RDTs could be explained by P. falciparum histidine rich protein 2 (PfHRP2) antigen persistence after recent malaria treatment. CONCLUSION: Malaria surveillance depending solely on RDTs needs well-integrated quality control procedures to assess the extent and impact of reduced sensitivity and specificity of RDTs on malaria control programmes.


Assuntos
Antígenos de Protozoários/análise , Coinfecção/diagnóstico , Testes Diagnósticos de Rotina/estatística & dados numéricos , Malária/diagnóstico , Vigilância da População , Proteínas de Protozoários/análise , Coinfecção/epidemiologia , Guiné Equatorial/epidemiologia , Reações Falso-Positivas , Incidência , Malária/epidemiologia , Malária Falciparum/diagnóstico , Malária Falciparum/epidemiologia , Ácidos Nucleicos/análise , Plasmodium falciparum/isolamento & purificação , Plasmodium malariae/isolamento & purificação , Plasmodium ovale/isolamento & purificação , Estudos Retrospectivos
2.
J Infect Dis ; 225(2): 257-268, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-34244739

RESUMO

BACKGROUND: Plasmodium falciparum malaria dominates throughout sub-Saharan Africa, but the prevalence of Plasmodium malariae, Plasmodium ovale spp., and Plasmodium vivax increasingly contribute to infection in countries that control malaria using P. falciparum-specific diagnostic and treatment strategies. METHODS: We performed quantitative polymerase chain reaction (qPCR) on 2987 dried blood spots from the 2015-2016 Malawi Demographic and Health Survey to identify presence and distribution of nonfalciparum infection. Bivariate models were used to determine species-specific associations with demographic and environmental risk factors. RESULTS: Nonfalciparum infections had broad spatial distributions. Weighted prevalence was 0.025 (SE, 0.004) for P. malariae, 0.097 (SE, 0.008) for P. ovale spp., and 0.001 (SE, 0.0005) for P. vivax. Most infections (85.6%) had low-density parasitemias ≤ 10 parasites/µL, and 66.7% of P. malariae, 34.6% of P. ovale spp., and 40.0% of P. vivax infections were coinfected with P. falciparum. Risk factors for P. malariae were like those known for P. falciparum; however, there were few risk factors recognized for P. ovale spp. and P. vivax, perhaps due to the potential for relapsing episodes. CONCLUSIONS: The prevalence of any nonfalciparum infection was 11.7%, with infections distributed across Malawi. Continued monitoring of Plasmodium spp. becomes critical as nonfalciparum infections become important sources of ongoing transmission.


Assuntos
Malária/epidemiologia , Plasmodium malariae/isolamento & purificação , Plasmodium ovale/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Adolescente , Adulto , Feminino , Humanos , Malária/diagnóstico , Malária Vivax/epidemiologia , Malaui/epidemiologia , Masculino , Plasmodium malariae/genética , Plasmodium ovale/genética , Plasmodium vivax/genética , Reação em Cadeia da Polimerase em Tempo Real , Adulto Jovem
3.
Malar J ; 20(1): 482, 2021 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-34949205

RESUMO

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


Assuntos
Erradicação de Doenças/estatística & dados numéricos , Malária/epidemiologia , Doenças Negligenciadas/epidemiologia , Plasmodium malariae/isolamento & purificação , Plasmodium ovale/isolamento & purificação , Humanos , Índia/epidemiologia , Malária/parasitologia , Doenças Negligenciadas/parasitologia , Prevalência
4.
Malar J ; 20(1): 218, 2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-33980241

RESUMO

BACKGROUND: Malaria control and elimination strategies are based on levels of transmission that are usually determined by data collected from health facilities. In endemic areas, asymptomatic Plasmodium infection is thought to represent the majority of infections, though they are not diagnosed nor treated. Therefore, there might be an underestimation of the malaria reservoir, resulting in inadequate control strategies. In addition, these untreated asymptomatic Plasmodium infections maintain transmission, making it difficult or impossible to reach malaria elimination goals. Thus, the aim of this study was to determine the prevalence of asymptomatic Plasmodium infections in southeastern Senegal. METHODS: A cross sectional study was conducted among asymptomatic individuals (N = 122) living in the village of Andiel located in Bandafassi, Kédougou, which consisted of about 200 inhabitants during the malaria transmission season in late October 2019. For each individual without malaria-related symptoms and who consented to participate, a rapid diagnostic test (RDT) was performed in the field. Results were confirmed in the laboratory with photo-induced electron transfer (PET-PCR). RESULTS: Malaria prevalence was 70.3% by PET-PCR and 41.8% by RDT. During the same period, the health post of the area reported 49. 1% test positivity rate by RDT. The majority of the infected study population, 92.9%, was infected with a single species and 7.1% had two or three species of Plasmodium. Plasmodium falciparum was predominant and represented 90.2% of the infections, while 6.5% were due to Plasmodium ovale and 3.3% to Plasmodium malariae. 59.4% of children targeted for SMC (zero to ten years old) were infected. CONCLUSION: In southeastern Senegal, where the transmission is the highest, malaria control strategies should address asymptomatic Plasmodium infections at the community level. The results suggest that this area could be eligible for mass drug administration. Moreover, non-falciparum species could be more common and its prevalence should be determined countrywide.


Assuntos
Infecções Assintomáticas/epidemiologia , Malária/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Malária/parasitologia , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Malária Vivax/epidemiologia , Malária Vivax/parasitologia , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/isolamento & purificação , Plasmodium malariae/isolamento & purificação , Plasmodium ovale/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Prevalência , Senegal/epidemiologia , Adulto Jovem
5.
Infect Genet Evol ; 91: 104797, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33676011

RESUMO

The performances of a commonly used Plasmodium falciparum-detecting rapid diagnostic test (RDT) were determined in symptomatic individuals living in Cameroon. Discrepancies between RDT and light microscopy (LM) results were further investigated, with a focus on non-falciparum malaria (NFM) which are still largely understudied in sub-Saharan Africa (sSA) countries. In the present study, a total of 355 individuals aged 1-65 years were enrolled in the study. Their signs/symptoms and sociodemographic characteristics were documented. The RDT reliability was evaluated using LM as gold standard method. Polymerase chain reaction (PCR) of Plasmodium 18S gene was performed for samples with discordant results between LM and RDT (i.e., RDT-/LM+, and RDT+/LM-). The PCR amplicons of NFM species were sequenced and BLASTed. The prevalence of malaria infection by LM was 95.7% (95% CI: 93.1-97.4%). The sensitivity and specificity of RDT for P. falciparum detection was 94.0% and 66.7%, respectively. By PCR assay, P. ovale curtisi (PoC) was found in 5 of the 30 discordant samples, and on sequence analysis these isolates were found to be phylogenetically closer to sequences reported from China-Myanmar border and Malaysia. This is the first report on molecular characterization of P. ovale subspecies in Cameroon. The study also outlines the good diagnostic performances of the RDT for detection of P. falciparum. Though, the presence of PoC indicated the importance of having RDTs targeting the NFM species in malaria diagnosis and treatment, which is presently limited in the country.


Assuntos
Malária/diagnóstico , Pacientes Ambulatoriais/estatística & dados numéricos , Plasmodium ovale/isolamento & purificação , Adolescente , Adulto , Camarões/epidemiologia , Criança , Pré-Escolar , Testes Diagnósticos de Rotina , Feminino , Humanos , Lactente , Malária/classificação , Malária/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
6.
Korean J Parasitol ; 59(1): 77-82, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33684990

RESUMO

As malaria remains a major health problem worldwide, various diagnostic tests have been developed, including microscopy-based and rapid diagnostic tests. LabChip real-time PCR (LRP) is a small and portable device used to diagnose malaria using lab-on-a-chip technology. This study aimed to evaluate the diagnostic performance of LRP for detecting malaria parasites. Two hundred thirteen patients and 150 healthy individuals were enrolled from May 2009 to October 2015. A diagnostic detectability of LRP for malaria parasites was compared to that of conventional RT-PCR. Sensitivity of LRP for Plasmodium vivax, P. falciparum, P. malariae, and P. ovale was 95.5%, 96.0%, 100%, and 100%, respectively. Specificity of LRP for P. vivax, P. falciparum, P. malariae, and P. ovale was 100%, 99.3%, 100%, and 100%, respectively. Cohen's Kappa coefficients between LRP and CFX96 for detecting P. vivax, P. falciparum, P. malariae, and P. ovale were 0.96, 0.98, 1.00, and 1.00, respectively. Significant difference was not observed between the results of LRP and conventional RT-PCR and microscopic examination. A time required to amplify DNAs using LRP and conventional RT-PCR was 27 min and 86 min, respectively. LRP amplified DNAs 2 times more fast than conventional RT-PCR due to the faster heat transfer. Therefore, LRP could be employed as a useful tool for detecting malaria parasites in clinical laboratories.


Assuntos
Testes Diagnósticos de Rotina/métodos , Dispositivos Lab-On-A-Chip , Malária/diagnóstico , Malária/parasitologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , DNA de Protozoário/análise , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , Plasmodium ovale/genética , Plasmodium ovale/isolamento & purificação , Plasmodium vivax/genética , Plasmodium vivax/isolamento & purificação , Sensibilidade e Especificidade , Adulto Jovem
7.
Malar J ; 19(1): 430, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33228684

RESUMO

BACKGROUND: Imported malaria is a major challenge for countries that are in malaria elimination stage such as Zambia. Legitimate cross-border activities add to the risk of transmission, necessitating determination of prevalence, characteristics and risk factors of imported and local malaria. METHODS: This cross-sectional study was conducted in 103 consented child and adult patients with clinical malaria symptoms, from selected health facilities in north-western Zambia. Patient demographic data and blood samples for malaria microscopy and full blood count were obtained. Chi-square and penalized logistic regression were performed to describe the characteristics and assess the risk factors of imported and local malaria in North-Western Province. RESULTS: Overall, malaria prevalence was 78.6% with 93.8% Plasmodium falciparum and 6.2% other species. The local cases were 72 (88.9%) while the imported were 9 (11.1%) out of the 81 positive participants. About 98.6% of the local cases were P. falciparum compared to 55.6% (χ2 = 52.4; p < 0.01) P. falciparum among the imported cases. Among the imported cases, 44% were species other than P. falciparum (χ2 = 48; p < 0.01) while among the local cases only 1.4% were. Gametocytes were present in 44% of the imported malaria cases and only in 2.8% of the local cases (χ2 = 48; p < 0.01). About 48.6% of local participants had severe anaemia compared to 33.3% of participants from the two neighbouring countries who had (χ2 = 4.9; p = 0.03). In the final model, only country of residence related positively to presence of species other than P. falciparum (OR = 39.0, CI [5.9, 445.9]; p < 0.01) and presence of gametocytes (OR = 23.1, CI [4.2, 161.6]; p < 0.01). CONCLUSION: Malaria prevalence in North-Western Province is high, with P. falciparum as the predominant species although importation of Plasmodium ovale and Plasmodium malariae is happening as well. Country of residence of patients is a major risk factor for malaria species and gametocyte presence. The need for enhanced malaria control with specific focus on border controls to detect and treat, for specific diagnosis and treatment according to species obtaining, for further research in the role of species and gametocytaemia in imported malaria, cannot be overemphasized.


Assuntos
Doenças Transmissíveis Importadas/epidemiologia , Malária Falciparum/epidemiologia , Plasmodium falciparum/isolamento & purificação , Plasmodium malariae/isolamento & purificação , Plasmodium ovale/isolamento & purificação , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Adulto Jovem , Zâmbia/epidemiologia
8.
Malar J ; 19(1): 366, 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33046056

RESUMO

BACKGROUND: Ghana is among the high-burden countries for malaria infections and recently reported a notable increase in malaria cases. While asymptomatic parasitaemia is increasingly recognized as a hurdle for malaria elimination, studies on asymptomatic malaria are scarce, and usually focus on children and on non-falciparum species. The present study aims to assess the prevalence of asymptomatic Plasmodium falciparum and non-falciparum infections in Ghanaian adults in the Ashanti region during the high transmission season. METHODS: Asymptomatic adult residents from five villages in the Ashanti Region, Ghana, were screened for Plasmodium species by rapid diagnostic test (RDT) and polymerase chain reaction (PCR) during the rainy season. Samples tested positive were subtyped using species-specific real-time PCR. For all Plasmodium ovale infections additional sub-species identification was performed. RESULTS: Molecular prevalence of asymptomatic Plasmodium infection was 284/391 (73%); only 126 (32%) infections were detected by RDT. While 266 (68%) participants were infected with Plasmodium falciparum, 33 (8%) were infected with Plasmodium malariae and 34 (9%) with P. ovale. The sub-species P. ovale curtisi and P. ovale wallikeri were identified to similar proportions. Non-falciparum infections usually presented as mixed infections with P. falciparum. CONCLUSIONS: Most adult residents in the Ghanaian forest zone are asymptomatic Plasmodium carriers. The high Plasmodium prevalence not detected by RDT in adults highlights that malaria eradication efforts must target all members of the population. Beneath Plasmodium falciparum, screening and treatment must also include infections with P. malariae, P. o. curtisi and P. o. wallikeri.


Assuntos
Malária/epidemiologia , Plasmodium falciparum/isolamento & purificação , Plasmodium malariae/isolamento & purificação , Plasmodium ovale/isolamento & purificação , Adulto , Infecções Assintomáticas/epidemiologia , Testes Diagnósticos de Rotina , Feminino , Gana/epidemiologia , Humanos , Malária Falciparum/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Adulto Jovem
9.
Turkiye Parazitol Derg ; 44(3): 126-131, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32928718

RESUMO

Objective: In present times, malaria remains an infectious disease with a high mortality rate in some regions of the world. It is predicted to preserve its importance as a disease in the future because of the traveling human populations from malaria-endemic African countries into the regions where malaria has been eradicated. The objective of this study is to evaluate the increasing imported malaria cases in the Turkish Republic of Northern Cyprus. Methods: In this study, we investigated 13 patients who were diagnosed with malaria between 2016 and 2019. We clinically evaluated all the cases. More importantly, we made the diagnosis of these patients by Giemsa-stained thin and thick blood smears, rapid malaria antigen tests, and genotyping (only for five patients) by real-time polymerase chain reaction. Additionally, we evaluated patients with malaria in terms of age, gender, and seasons. Results: In the diagnosed malaria cases, 11 (84.4%) of them were male and 2 (15.6%) were female. There was no significance between malaria infection and gender (p=0.358). Plasmodium falciparum, Plasmodium vivax, and Plasmodium ovale infection were detected in ten patients (76.9%), two (15.4%) patients, and one (7.7%) patient, respectively. There was a significant increase (p=0.003) in the malaria cases in 2019 (n=9). The seasonal comparison revealed that malaria infections are most common in autumn (8/13, 61.5%). Conclusion: Despite the eradication of malaria in Turkish Republic of Northern Cyprus, the rising number of recently imported cases increases the risk of emerging local cases. Malaria infection should be immediately suspected, particularly, in foreign patients who travel from the malaria-endemic region and present with symptoms such as fever and shivering if the laboratory findings especially detect thrombocytopenia.


Assuntos
Malária/epidemiologia , Adolescente , Adulto , África , Chipre/epidemiologia , Feminino , Humanos , Malária/etiologia , Malária/prevenção & controle , Masculino , Plasmodium falciparum/isolamento & purificação , Plasmodium ovale/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Risco , Estações do Ano , Viagem , Adulto Jovem
11.
Malar J ; 19(1): 264, 2020 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-32698906

RESUMO

BACKGROUND: There have been an increasing number of imported cases of malaria in Hubei Province in recent years. In particular, the number of cases of Plasmodium ovale spp. and Plasmodium malariae significantly increased, which resulted in increased risks during the malaria elimination phase. The purpose of this study was to acquire a better understanding of the epidemiological characteristics of P. ovale spp. and P. malariae imported to Hubei Province, China, so as to improve case management. METHODS: Data on all malaria cases from January 2014 to December 2018 in Hubei Province were extracted from the China national diseases surveillance information system (CNDSIS). This descriptive study was conducted to analyse the prevalence trends, latency periods, interval from onset of illness to diagnosis, and misdiagnosis of cases of P. ovale spp. and P. malariae malaria. RESULTS: During this period, 634 imported malaria cases were reported, of which 87 P. ovale spp. (61 P. ovale curtisi and 26 P. ovale wallikeri) and 18 P. malariae cases were confirmed. The latency periods of P. ovale spp., P. malariae, Plasmodium vivax, and Plasmodium falciparum differed significantly, whereas those of P. ovale curtisi and P. ovale wallikeri were no significant difference. The proportion of correct diagnosis of P. ovale spp. and P. malariae malaria cases were 48.3% and 44.4%, respectively, in the hospital or lower-level Centers for Disease Control and Prevention (CDC). In the Provincial Reference Laboratory, the sensitivity of microscopy and rapid diagnostic tests was 94.3% and 70.1%, respectively, for detecting P. ovale spp., and 88.9% and 38.9%, respectively, for detecting P. malariae. Overall, 97.7% (85/87) of P. ovale spp. cases and 94.4% (17/18) of P. malariae cases originated from Africa. CONCLUSION: The increase in the number of imported P. ovale spp. and P. malariae cases, long latency periods, and misdiagnosis pose a challenge to this region. Therefore, more attention should be paid to surveillance of imported cases of P. ovale spp. and P. malariae infection to reduce the burden of public health and potential risk of malaria.


Assuntos
Doenças Transmissíveis Importadas/epidemiologia , Erros de Diagnóstico/estatística & dados numéricos , Infecção Latente/diagnóstico , Malária , Plasmodium malariae/isolamento & purificação , Plasmodium ovale/isolamento & purificação , China/epidemiologia , Infecção Latente/epidemiologia , Malária/diagnóstico , Malária/epidemiologia , Malária/transmissão , Prevalência
12.
Am J Trop Med Hyg ; 103(3): 1107-1110, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32618263

RESUMO

Asymptomatic and/or low-density malaria infection has been acknowledged as an obstacle to achieving a malaria-free country. This study aimed to determine the prevalence of asymptomatic and/or low-density malaria infection in previously reported malarious localities using nested PCR in four states, namely, Johor, Pahang, Kelantan, and Selangor, between June 2019 and January 2020. Blood samples (n = 585) were collected and were extracted using a QIAamp blood kit. The DNA was concentrated and subjected to nested PCR. Thin and thick blood smears were examined as well. Of the 585 samples collected, 19 were positive: 10 for Plasmodium knowlesi, eight for Plasmodium vivax, and one for Plasmodium ovale. Asymptomatic and/or low-density malaria infection is a threat to malaria elimination initiatives. Eliminating countries should develop guidance policy on the importance of low-density malaria infection which includes detection and treatment policy.


Assuntos
Infecções Assintomáticas/epidemiologia , Malária Vivax/epidemiologia , Malária/epidemiologia , Plasmodium/isolamento & purificação , Adolescente , Adulto , Feminino , Humanos , Malária/parasitologia , Malária Vivax/parasitologia , Malásia/epidemiologia , Masculino , Pessoa de Meia-Idade , Plasmodium/genética , Plasmodium knowlesi/genética , Plasmodium knowlesi/isolamento & purificação , Plasmodium ovale/genética , Plasmodium ovale/isolamento & purificação , Plasmodium vivax/genética , Plasmodium vivax/isolamento & purificação , Reação em Cadeia da Polimerase , Prevalência , Adulto Jovem
13.
Malar J ; 19(1): 246, 2020 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-32660505

RESUMO

BACKGROUND: Eighteen imported ovale malaria cases imported from Myanmar and various African countries have been reported in Yunnan Province, China from 2013 to 2018. All of them have been confirmed by morphological examination and 18S small subunit ribosomal RNA gene (18S rRNA) based PCR in YNRL. Nevertheless, the subtypes of Plasmodium ovale could not be identified based on 18S rRNA gene test, thus posing challenges on its accurate diagnosis. To help establish a more sensitive and specific method for the detection of P. ovale genes, this study performs sequence analysis on k13-propeller polymorphisms in P. ovale. METHODS: Dried blood spots (DBS) from ovale malaria cases were collected from January 2013 to December 2018, and the infection sources were confirmed according to epidemiological investigation. DNA was extracted, and the coding region (from 206th aa to 725th aa) in k13 gene propeller domain was amplified using nested PCR. Subsequently, the amplified products were sequenced and compared with reference sequence to obtain CDS. The haplotypes and mutation loci of the CDS were analysed, and the spatial structure of the amino acid peptide chain of k13 gene propeller domain was predicted by SWISS-MODEL. RESULTS: The coding region from 224th aa to 725th aa of k13 gene from P. ovale in 83.3% of collected samples (15/18) were amplified. Three haplotypes were observed in 15 samples, and the values of Ka/Ks, nucleic acid diversity index (π) and expected heterozygosity (He) were 3.784, 0.0095, and 0.4250. Curtisi haplotype, Wallikeri haplotype, and mutant type accounted for 73.3% (11/15), 20.0% (3/15), and 6.7% (1/15). The predominant haplotypes of P. ovale curtisi were determined in all five Myanmar isolates. Of the ten African isolates, six were identified as P. o. curtisi, three were P. o. wallikeri and one was mutant type. Base substitutions between the sequences of P. o. curtisi and P. o. wallikeri were determined at 38 loci, such as c.711. Moreover, the A > T base substitution at c.1428 was a nonsynonymous mutation, resulting in amino acid variation of T476S in the 476th position. Compared with sequence of P. o. wallikeri, the double nonsynonymous mutations of G > A and A > T at the sites of c.1186 and c.1428 leads to the variations of D396N and T476S for the 396th and 476th amino acids positions. For P. o. curtisi and P. o. wallikeri, the peptide chains in the coding region from 224th aa to 725th aa of k13 gene merely formed a monomeric spatial model, whereas the double-variant peptide chains of D396N and T476S formed homodimeric spatial model. CONCLUSION: The propeller domain of k13 gene in the P. ovale isolates imported into Yunnan Province from Myanmar and Africa showed high differentiation. The sequences of Myanmar-imported isolates belong to P. o. curtisi, while the sequences of African isolates showed the sympatric distribution from P. o. curtisi, P. o. wallikeri and mutant isolates. The CDS with a double base substitution formed a dimeric spatial model to encode the peptide chain, which is completely different from the monomeric spatial structure to encode the peptide chain from P. o. curtisi and P. o. wallikeri.


Assuntos
Testes Diagnósticos de Rotina/métodos , Plasmodium ovale/isolamento & purificação , Polimorfismo Genético , China , Genótipo , Mianmar , Plasmodium ovale/classificação , Plasmodium ovale/genética
14.
Galicia clin ; 81(3): 85-86, jul. 2020. ilus
Artigo em Inglês | IBECS | ID: ibc-199181

RESUMO

BACKGROUND: Monomicrobial imported infection by Plasmodium ovale is very rare. Case presentation: We report a case of complicated imported malaria by Plasmodium ovale in a man who suffered from subacute recurrent fever, thrombocytopenia and splenomegaly. CONCLUSION: Both the patient history and a search of epidemiological medical history were fundamental for confirming the suspicion


No disponible


Assuntos
Humanos , Masculino , Adulto , Malária/complicações , Plasmodium ovale/isolamento & purificação , Antimaláricos/uso terapêutico , Malária/microbiologia , Plasmodium ovale/patogenicidade , Esplenomegalia/diagnóstico por imagem , Espanha/epidemiologia
15.
BMC Public Health ; 20(1): 857, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32503526

RESUMO

BACKGROUND: The European region achieved interruption of malaria transmission during the 1970s. Since then, malaria control programs were replaced by surveillance systems in order to prevent possible re-emergence of this disease. Sporadic cases of non-imported malaria were recorded in several European countries in the past decade and locally transmitted outbreaks of Plasmodium vivax, most probably supported by Anopheles sacharovi, have been repeatedly reported from Greece since 2009. The possibility of locally-transmitted malaria has been extensively studied in Italy where the former malaria vector An. labranchiae survived the control campaign which led to malaria elimination. In this study, we present paradigmatic cases that occurred during a 2017 unusual cluster, which caused strong concern in public opinion and were carefully investigated after the implementation of the updated malaria surveillance system. METHODS: For suspected locally-transmitted malaria cases, alerts to Ministry of Health (MoH) and the National Institute of Health (ISS) were mandated by the Local Health Services (LHS). Epidemiological investigations on the transmission modes and the identification of possible infection's source were carried out by LHS, MoH and ISS. Entomological investigations were implemented locally for all suspected locally-transmitted cases that occurred in periods suitable to anopheline activity. Molecular diagnosis by nested-PCR for the five human Plasmodium species was performed to support microscopic diagnosis. In addition, genotyping of P. falciparum isolate was carried out to investigate putative sources of infection and transmission modalities. RESULTS: In 2017, a cluster of seven non-imported cases was recorded from August through October. Among them, P. ovale curtisi was responsible of one case whereas six cases were caused by P. falciparum. Two cases were proved to be nosocomial while the other five were recorded as cryptic at the end of epidemiological investigations. CONCLUSIONS: The epidemiological evidence shows that the locally acquired events are sporadic, often remain unresolved and classified as cryptic ones despite investigative efforts. The "cluster" of seven non-imported cases that occurred in 2017 in different regions of Italy therefore represents a conscious alert that should lead us to maintain a constant level of surveillance in a former malaria endemic country.


Assuntos
Surtos de Doenças/estatística & dados numéricos , Malária Falciparum/epidemiologia , Malária/epidemiologia , Mosquitos Vetores , Vigilância da População , Animais , Feminino , Humanos , Itália/epidemiologia , Malária Falciparum/microbiologia , Malária Falciparum/transmissão , Masculino , Plasmodium falciparum/isolamento & purificação , Plasmodium ovale/isolamento & purificação , Reação em Cadeia da Polimerase
17.
Am J Trop Med Hyg ; 103(3): 1085-1087, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32314695

RESUMO

In clinical practice, mixed-species malaria infections are often not detected by light microscopy (LM) or rapid diagnostic test, as a low number of parasites of one species may occur. Here, we report the case of an 8-year-old girl migrating with her family from Afghanistan with a two-species mixed infection with Plasmodium vivax and Plasmodium ovale. This case demonstrates the significance of molecular testing in the detection of mixed-species malaria infections and highlights the importance of a detailed data analysis during the medical validation procedure to prevent underestimation of mixed-species infections. To our knowledge, this is the first case report of a two-species mixed infection comprising both P. vivax and P. ovale confirmed by LM and different real-time polymerase chain reaction (PCR) approaches.


Assuntos
Malária/diagnóstico , Plasmodium ovale/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Afeganistão , Criança , Feminino , Humanos , Malária/parasitologia , Plasmodium ovale/genética , Plasmodium vivax/genética , Reação em Cadeia da Polimerase em Tempo Real
18.
Transfusion ; 60(5): 955-964, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32282944

RESUMO

BACKGROUND: Malaria remains a leading transfusion associated infectious risk in endemic areas. However, the prevalence of malaria parasitemia has not been well characterized in blood donor populations. This study sought to determine the prevalence of Plasmodium in red blood cell (RBC) and whole blood (WB) units after the rainy season in Uganda. METHODS AND MATERIALS: Between May and July 2018, blood was collected from the sample diversion pouch of 1000 WB donors in Kampala and Jinja, Uganda. The RBC pellet from ethylenediamine tetraacetic acid (EDTA) anticoagulated blood was stored at -80°C until testing. DNA was extracted and nested PCR was used to screen samples at the genus level for Plasmodium, with positive samples further tested for species identification. RESULTS: Malaria parasitemia among asymptomatic, eligible blood donors in two regions of Uganda was 15.4%; 87.7% (135/154) of infections were with P. falciparum, while P. malariae and P. ovale were also detected. There were 4.3% of blood donors who had mixed infection with multiple species. Older donors (>30 years vs. 17-19 years; aPR = 0.31 [95% CI = 0.17-0.58]), females (aPR = 0.60 [95% CI = 0.42-0.87]), repeat donors (aPR = 0.44 [95% CI = 0.27-0.72]) and those donating near the capital city of Kampala versus rural Jinja region (aPR = 0.49 [95% CI = 0.34-0.69]) had a lower prevalence of malaria parasitemia. CONCLUSIONS: A high proportion of asymptomatic blood donors residing in a malaria endemic region demonstrate evidence of parasitemia at time of donation. Further research is needed to quantify the risk and associated burden of transfusion-transmitted malaria (TTM) in order to inform strategies to prevent TTM.


Assuntos
Doadores de Sangue/estatística & dados numéricos , Malária/epidemiologia , Parasitemia/epidemiologia , Adolescente , Adulto , Infecções Assintomáticas/epidemiologia , Transfusão de Sangue/estatística & dados numéricos , Estudos Transversais , Feminino , Humanos , Malária/sangue , Malária Falciparum/sangue , Malária Falciparum/epidemiologia , Masculino , Pessoa de Meia-Idade , Parasitemia/sangue , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium falciparum/isolamento & purificação , Plasmodium malariae/crescimento & desenvolvimento , Plasmodium malariae/isolamento & purificação , Plasmodium ovale/crescimento & desenvolvimento , Plasmodium ovale/isolamento & purificação , Prevalência , Uganda/epidemiologia , Adulto Jovem
20.
Korean J Parasitol ; 58(1): 61-65, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32145729

RESUMO

Majority of the imported malaria cases in Korea is attributed to Plasmodium falciparum and P. vivax infections, whereas P. malariae and P. ovale infections are very rare. Falciparum and ovale malaria are mostly imported from Africa, while most of the vivax malaria cases are imported from Southeast Asia. Here, we report 6 Korean imported ovale malaria cases (4 males and 2 females) who had visited in Africa during 2013-2016. These subjects were diagnosed with P. ovale based on microscopic findings, Plasmodium species-specific nested-PCR, and phylogenetic clade using 18S rRNA gene sequences. We identified 2 P. ovale subtypes, 1 P. ovale curtisi (classic type) and 5 P. ovale wallikeri (variant type). All patients were treated with chloroquine and primaquine, and no relapse or recrudescence was reported for 1 year after treatment. With increase of travelers to the countries where existing Plasmodium species, the risk of Plasmodium infection is also increasing. Molecular monitoring for imported malaria parasites should be rigorously and continuously performed to enable diagnosis and certification of Plasmodium spp.


Assuntos
Malária/diagnóstico , Malária/parasitologia , Plasmodium ovale/genética , Plasmodium ovale/isolamento & purificação , Povo Asiático , Feminino , Humanos , Masculino , RNA Ribossômico 18S/genética , África do Sul , Fatores de Tempo , Viagem
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