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Harald Noedl - One of the best experts on this subject based on the ideXlab platform.
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Novel high resolution melting (HRM) and snapback assays for simultaneous detection and differentiation of Plasmodium ovale spp.
Acta tropica, 2019Co-Authors: Aline Lamien-meda, Hans-peter Fuehrer, Harald NoedlAbstract:Abstract Plasmodium ovale spp. are two of the six species of apicomplexan parasites belonging to the genus Plasmodium commonly causing disease in humans. A recent phylogeny study has identified both Plasmodium ovale species (P. ovale curtisi and P. ovale wallikeri) as two sympatric occurring species. The actual prevalence and clinical relevance of P. ovale spp. are likely underestimated due to low parasitemia and mixed infections, which pose a major challenge to microscopic diagnosis and are frequently undetectable using malaria Rapid Diagnostic Tests (RDTs). The aim of this work is to develop a HRM-based assay for simultaneous detection and differentiation of P. ovale wallikeri and P. ovale curtisi. Thirty three well-documented P. ovale spp. samples from previous studies were used for this study. The newly developed High Resolution Melting (HRM) assay targeting the apicoplast genome was highly specific to both P. ovale species. Adding a snapback tail at the 5’ end of the forward primer for a nested HRM PCR, increased the melting temperature (Tm) difference between the two species. To our knowledge this study reports the first direct HRM assay developed on the apicoplast genome, specific for both P. ovale species. This method provides added value to the WHO open request of developing new practical malaria diagnostic methods for the malaria elimination program and could contribute to a quick and efficient diagnosis of low-level parasitemia, symptomatic or asymptomatic, as well as mixed or single P. ovale infections.
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Plasmodium ovale wallikeri in Western Lowland Gorillas and Humans, Central African Republic.
Emerging infectious diseases, 2018Co-Authors: Mwanahamisi I. Mapua, Hans-peter Fuehrer, Harald Noedl, Klára J. Petrželková, Angelique Todd, Moneeb A. Qablan, David ModrýAbstract:Human malaria parasites have rarely been reported from free-ranging great apes. Our study confirms the presence of the human malaria parasite Plasmodium ovale wallikeri in western lowland gorillas and humans in Dzanga Sangha Protected Areas, Central African Republic, and discusses implications for malaria epidemiology.
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Recent Advances in Detection of Plasmodium ovale: Implications of Separation into the Two Species Plasmodium ovale wallikeri and Plasmodium ovale curtisi
Journal of clinical microbiology, 2013Co-Authors: Hans-peter Fuehrer, Harald NoedlAbstract:Recent molecular studies indicate that Plasmodium ovale malaria is caused by two closely related species of protozoan parasites, thereby imposing new challenges for detection and species differentiation. This minireview explores the potential value of innovative methods for the molecular diagnosis of malaria with a strong emphasis on the discrimination and genotyping of P. ovale wallikeri and P. ovale curtisi as well as tools for the simultaneous detection of P. ovale sp. An update for the widely used NP-1993 to NP-2005 (SSU rRNA) protocols for all human malaria parasites is discussed.
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Plasmodium ovale curtisi and Plasmodium ovale wallikeri in North-West Ethiopia.
Malaria journal, 2013Co-Authors: Abebe Alemu, Hans-peter Fuehrer, Gebeyaw Getnet, Belay Tessema, Harald NoedlAbstract:In Ethiopia Plasmodium falciparum and Plasmodium vivax are the dominant species accounting for roughly 60 and 40% of malaria cases, respectively. Recently a major shift from P. falciparum to P. vivax has been observed in various parts of the country but the epidemiology of the other human malaria species, Plasmodium ovale spp. and Plasmodium malariae remains poorly understood. The aim of this study was to assess P. ovale curtisi and wallikeri infection in north-west Ethiopia by using microscopy and nested PCR. A health institution-based survey using non-probability sampling techniques was conducted at Maksegnet, Enfranze and Kola Diba health centres and Metema hospital in North Gondar. Three-hundred patients with signs and symptoms consistent with malaria were included in this study and capillary blood was collected for microscopic examination and molecular analysis of Plasmodium species. Samples were collected on Whatman 903 filter papers, stored in small plastic bags with desiccant and transported to Vienna (Austria) for molecular analysis. Data from study participants were entered and analysed by SPSS 20 software. Out of 300 study participants (167 males and 133 females), 184 samples were classified positive for malaria (133 P. falciparum and 51 P. vivax) by microscopy. By species-specific PCR 233 Plasmodium spp (95% CI: 72.6-82) were detected and the majority 155 (66.5%, 95% CI: 60.2-72.3) were P. falciparum followed by P. vivax 69 (29.6%, 95% CI; 24.1-35.8) and 9 (3.9%, 95% CI: 2-7.2) samples were positive for P. ovale. Seven of P. ovale parasites were confirmed as P. ovale wallikeri and two were confirmed as P. ovale curtisi. None of the samples tested positive for P. malariae. During microscopic examination there were high (16.3%) false negative reports and all mixed infections and P. ovale cases were missed or misclassified. This study indicates that P. ovale malaria is under-reported in Ethiopia and provides the first known evidence of the sympatric distribution of indigenous P. ovale wallikeri and P. ovale curtisi in Ethiopia. Therefore, further studies assessing the prevalence of the rare species P. ovale and P. malariae are urgently needed to better understand the species distribution and to adapt malaria control strategies.
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Two Techniques for Simultaneous Identification of Plasmodium ovale curtisi and Plasmodium ovale wallikeri by Use of the Small-Subunit rRNA Gene
Journal of clinical microbiology, 2012Co-Authors: Hans-peter Fuehrer, Ingrid Bloeschl, Marie-therese Stadler, Katharina Buczolich, Harald NoedlAbstract:The primers traditionally used to detect Plasmodium ovale infections are known for not binding all P. ovale parasites within the small-subunit rRNA gene when used alone. We describe a simple, cost- and time-efficient multiplex nested PCR and a nested PCR using a novel set of primers for the simultaneous detection of P. ovale curtisi and P. ovale wallikeri.
Hans-peter Fuehrer - One of the best experts on this subject based on the ideXlab platform.
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Novel high resolution melting (HRM) and snapback assays for simultaneous detection and differentiation of Plasmodium ovale spp.
Acta tropica, 2019Co-Authors: Aline Lamien-meda, Hans-peter Fuehrer, Harald NoedlAbstract:Abstract Plasmodium ovale spp. are two of the six species of apicomplexan parasites belonging to the genus Plasmodium commonly causing disease in humans. A recent phylogeny study has identified both Plasmodium ovale species (P. ovale curtisi and P. ovale wallikeri) as two sympatric occurring species. The actual prevalence and clinical relevance of P. ovale spp. are likely underestimated due to low parasitemia and mixed infections, which pose a major challenge to microscopic diagnosis and are frequently undetectable using malaria Rapid Diagnostic Tests (RDTs). The aim of this work is to develop a HRM-based assay for simultaneous detection and differentiation of P. ovale wallikeri and P. ovale curtisi. Thirty three well-documented P. ovale spp. samples from previous studies were used for this study. The newly developed High Resolution Melting (HRM) assay targeting the apicoplast genome was highly specific to both P. ovale species. Adding a snapback tail at the 5’ end of the forward primer for a nested HRM PCR, increased the melting temperature (Tm) difference between the two species. To our knowledge this study reports the first direct HRM assay developed on the apicoplast genome, specific for both P. ovale species. This method provides added value to the WHO open request of developing new practical malaria diagnostic methods for the malaria elimination program and could contribute to a quick and efficient diagnosis of low-level parasitemia, symptomatic or asymptomatic, as well as mixed or single P. ovale infections.
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Molecular evidence for relapse of an imported Plasmodium ovale wallikeri infection
Malaria journal, 2018Co-Authors: Luzia Veletzky, Hans-peter Fuehrer, Mirjam Groger, Heimo Lagler, Julia Walochnik, Herbert Auer, Michael RamharterAbstract:Background Malaria caused by Plasmodium ovale spp. has been neglected by and large from research and has received only little scientific attention during the past decades. ovale malaria is considered to feature relapses by liver hypnozoites although scientific evidence for this paradigm is scarce.
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Plasmodium ovale wallikeri in Western Lowland Gorillas and Humans, Central African Republic.
Emerging infectious diseases, 2018Co-Authors: Mwanahamisi I. Mapua, Hans-peter Fuehrer, Harald Noedl, Klára J. Petrželková, Angelique Todd, Moneeb A. Qablan, David ModrýAbstract:Human malaria parasites have rarely been reported from free-ranging great apes. Our study confirms the presence of the human malaria parasite Plasmodium ovale wallikeri in western lowland gorillas and humans in Dzanga Sangha Protected Areas, Central African Republic, and discusses implications for malaria epidemiology.
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Recent Advances in Detection of Plasmodium ovale: Implications of Separation into the Two Species Plasmodium ovale wallikeri and Plasmodium ovale curtisi
Journal of clinical microbiology, 2013Co-Authors: Hans-peter Fuehrer, Harald NoedlAbstract:Recent molecular studies indicate that Plasmodium ovale malaria is caused by two closely related species of protozoan parasites, thereby imposing new challenges for detection and species differentiation. This minireview explores the potential value of innovative methods for the molecular diagnosis of malaria with a strong emphasis on the discrimination and genotyping of P. ovale wallikeri and P. ovale curtisi as well as tools for the simultaneous detection of P. ovale sp. An update for the widely used NP-1993 to NP-2005 (SSU rRNA) protocols for all human malaria parasites is discussed.
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Plasmodium ovale curtisi and Plasmodium ovale wallikeri in North-West Ethiopia.
Malaria journal, 2013Co-Authors: Abebe Alemu, Hans-peter Fuehrer, Gebeyaw Getnet, Belay Tessema, Harald NoedlAbstract:In Ethiopia Plasmodium falciparum and Plasmodium vivax are the dominant species accounting for roughly 60 and 40% of malaria cases, respectively. Recently a major shift from P. falciparum to P. vivax has been observed in various parts of the country but the epidemiology of the other human malaria species, Plasmodium ovale spp. and Plasmodium malariae remains poorly understood. The aim of this study was to assess P. ovale curtisi and wallikeri infection in north-west Ethiopia by using microscopy and nested PCR. A health institution-based survey using non-probability sampling techniques was conducted at Maksegnet, Enfranze and Kola Diba health centres and Metema hospital in North Gondar. Three-hundred patients with signs and symptoms consistent with malaria were included in this study and capillary blood was collected for microscopic examination and molecular analysis of Plasmodium species. Samples were collected on Whatman 903 filter papers, stored in small plastic bags with desiccant and transported to Vienna (Austria) for molecular analysis. Data from study participants were entered and analysed by SPSS 20 software. Out of 300 study participants (167 males and 133 females), 184 samples were classified positive for malaria (133 P. falciparum and 51 P. vivax) by microscopy. By species-specific PCR 233 Plasmodium spp (95% CI: 72.6-82) were detected and the majority 155 (66.5%, 95% CI: 60.2-72.3) were P. falciparum followed by P. vivax 69 (29.6%, 95% CI; 24.1-35.8) and 9 (3.9%, 95% CI: 2-7.2) samples were positive for P. ovale. Seven of P. ovale parasites were confirmed as P. ovale wallikeri and two were confirmed as P. ovale curtisi. None of the samples tested positive for P. malariae. During microscopic examination there were high (16.3%) false negative reports and all mixed infections and P. ovale cases were missed or misclassified. This study indicates that P. ovale malaria is under-reported in Ethiopia and provides the first known evidence of the sympatric distribution of indigenous P. ovale wallikeri and P. ovale curtisi in Ethiopia. Therefore, further studies assessing the prevalence of the rare species P. ovale and P. malariae are urgently needed to better understand the species distribution and to adapt malaria control strategies.
Gerardo Rojo-marcos - One of the best experts on this subject based on the ideXlab platform.
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Prospective comparative multi-centre study on imported Plasmodium ovale wallikeri and Plasmodium ovale curtisi infections.
Malaria journal, 2018Co-Authors: Gerardo Rojo-marcos, José Miguel Rubio-muñoz, Andrea Angheben, Stéphane Jauréguiberry, Silvia García-bujalance, Lina Rachele Tomasoni, Natalia Rodriguez-valero, José Manuel Ruiz-giardín, Joaquín Salas-coronas, Juan Cuadros-gonzálezAbstract:Few previous retrospective studies suggest that Plasmodium ovale wallikeri seems to have a longer latency period and produces deeper thrombocytopaenia than Plasmodium ovale curtisi. Prospective studies were warranted to better assess interspecies differences. Patients with imported P. ovale spp. infection diagnosed by thick or thin film, rapid diagnostic test (RDT) or polymerase chain reaction (PCR) were recruited between March 2014 and May 2017. All were confirmed by DNA isolation and classified as P. o. curtisi or P. o. wallikeri using partial sequencing of the ssrRNA gene. Epidemiological, analytical and clinical differences were analysed by statistical methods. A total of 79 samples (35 P. o. curtisi and 44 P. o. wallikeri) were correctly genotyped. Males predominate in wallikeri group (72.7%), whereas were 48.6% in curtisi group. Conversely, 74.3% of curtisi group were from patients of African ethnicity, whilst 52.3% of Caucasians were infected by P. o. wallikeri. After performing a multivariate analysis, more thrombocytopaenic patients (p = 0.022), a lower number of platelets (p = 0.015), a higher INR value (p = 0.041), and shorter latency in Caucasians (p = 0.034) were significantly seen in P. o. wallikeri. RDT sensitivity was 26.1% in P. o. curtisi and 42.4% in P. o. wallikeri. Nearly 20% of both species were diagnosed only by PCR. Total bilirubin over 3 mg/dL was found in three wallikeri cases. Two patients with curtisi infection had haemoglobin under 7 g/dL, one of them also with icterus. A wallikeri patient suffered from haemophagocytosis. Chemoprophylaxis failed in 14.8% and 35% of curtisi and wallikeri patients, respectively. All treated patients with various anti-malarials which included artesunate recovered. Diabetes mellitus was described in 5 patients (6.32%), 4 patients of wallikeri group and 1 curtisi. Imported P. o. wallikeri infection may be more frequent in males and Caucasians. Malaria caused by P. o. wallikeri produces more thrombocytopaenia, a higher INR and shorter latency in Caucasians and suggests a more pathogenic species. Severe cases can be seen in both species. Chemoprophylaxis seems less effective in P. ovale spp. infection than in P. falciparum, but any anti-malarial drug is effective as initial treatment. Diabetes mellitus could be a risk factor for P. ovale spp. infection.
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LAMP kit for diagnosis of non-falciparum malaria in Plasmodium ovale infected patients
Malaria journal, 2017Co-Authors: Juan Cuadros, Gerardo Rojo-marcos, Alexandra Martin Ramírez, Iveth J. González, Xavier C. Ding, Ramon Perez Tanoira, Peña Gómez-herruz, José M. RubioAbstract:Background Microscopy and rapid diagnosis tests have a limited sensitivity in diagnosis of malaria by Plasmodium ovale. The LAMP kit (LoopAMP®) can be used in the field without special equipment and could have an important role in malaria control programmes in endemic areas and for malaria diagnosis in returned travellers. The performance of the Pan primer of the kit in detecting malaria by P. ovale was compared with the results of standard nPCR in samples of patients returning from P. ovale endemic areas.
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Infección por Plasmodium ovale: descripción de 16 casos y revisión del tema
Enfermedades infecciosas y microbiologia clinica, 2011Co-Authors: Gerardo Rojo-marcos, Juan Cuadros-gonzález, Peña Gómez-herruz, Luis Gete-garcía, Montserrat López-rubio, Gema Esteban-gutierrezAbstract:Introduction: Information on imported malaria caused by Plasmodium ovale parasite is scarce. Methods: Sixteen cases were studied retrospectively. Results: Most cases had an incubation period ranging from 2 to 53 months and were African immigrants recently arrived or residents in Spain who had visited West Africa. Ten patients had underlying diseases and 5 suffered from a previous P. falciparum infection. Three patients had severe complications and 3 were asymptomatic. Rapid malaria test was positive in 2 out of 10 patients. Five were diagnosed only with PCR. Conclusions: P. ovale infection can be asymptomatic or cause severe complications up to 5 years after
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Acute respiratory distress syndrome in a case of Plasmodium ovale malaria.
The American journal of tropical medicine and hygiene, 2008Co-Authors: Gerardo Rojo-marcos, Juan Cuadros-gonzález, José María Mesa-latorre, Ana María Culebras-lópez, Raúl De Pablo-sánchezAbstract:Acute respiratory distress syndrome is a well-known complication in Plasmodium falciparum infection. It is less frequently described in Plasmodium vivax, and only one case is reported in Plasmodium ovale. Here we present the second description of this pulmonary complication in a P. ovale acute infection.
Jean-françois Trape - One of the best experts on this subject based on the ideXlab platform.
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A 20-Year Longitudinal Study of Plasmodium ovale and Plasmodium malariae Prevalence and Morbidity in a West African Population
PloS one, 2014Co-Authors: Clémentine Roucher, Adama Tall, Sokhna, Christophe Rogier, Jean-françois TrapeAbstract:Background Plasmodium ovale and Plasmodium malariae have long been reported to be widely distributed in tropical Africa and in other major malaria-endemic areas of the world. However, little is known about the burden caused by these two malaria species.
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diagnostic criteria and risk factors for Plasmodium ovale malaria
The Journal of Infectious Diseases, 2002Co-Authors: Farba Faye, André Spiegel, Adama Tall, Didier Fontenille, Christophe Rogier, Cheikh Sokhna, Jean-françois TrapeAbstract:Plasmodium ovale is a common malaria parasite in Africa, but the epidemiology of P. ovale malaria is poorly known. Exposure to malaria, parasitemia, and morbidity were monitored for 6 years among the residents of a village in Senegal. The relationship between the level of P. ovale parasitemia and fever risk were analyzed, and diagnostic criteria for clinical P. ovale malaria were established. Then the relationships between the occurrence of P. ovale clinical malaria and a series of entomological, epidemiological, and genetic factors were investigated. There was no increased risk of fever when the P. ovale parasite count was <800 parasites/microL of blood. Of 6621 episodes of illness, 114 (1.7%) were attributable to P. ovale. Although most clinical episodes occurred during early childhood, a low incidence of the disease persisted among adults. Sickle cell trait carriers had increased susceptibility to the disease.
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Diagnostic criteria and risk factors for Plasmodium ovale malaria.
The Journal of infectious diseases, 2002Co-Authors: Farba B.k. Faye, André Spiegel, Adama Tall, Sokhna, Didier Fontenille, Christophe Rogier, Jean-françois TrapeAbstract:Plasmodium ovale is a common malaria parasite in Africa, but the epidemiology of P. ovale malaria is poorly known. Exposure to malaria, parasitemia, and morbidity were monitored for 6 years among the residents of a village in Senegal. The relationship between the level of P. ovale parasitemia and fever risk were analyzed, and diagnostic criteria for clinical P. ovale malaria were established. Then the relationships between the occurrence of P. ovale clinical malaria and a series of entomological, epidemiological, and genetic factors were investigated. There was no increased risk of fever when the P. ovale parasite count was
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Plasmodium ovale in a highly malaria endemic area of Senegal
Transactions of the Royal Society of Tropical Medicine and Hygiene, 1998Co-Authors: Farba B.k. Faye, Christophe Rogier, Lassana Konate, Jean-françois TrapeAbstract:During 4 months, from June to September 1990, the population of Dielmo village, Senegal, an area of intense and perennial malaria transmission, was enrolled in a follow-up study including daily clinical surveillance and bi-weekly malaria parasitaemia monitoring. Thick blood film examinations indicated that 48.5% of children (49/101) and 32.4% of adults (34/105) were infected at least once by Plasmodium ovale during the study period; 148 distinct episodes of patent parasitaemia were observed, with estimated maximum durations of 3-115 d. The mean duration at first decreased significantly with age, from 11.4 d in children under 5 years old to 4.2 d in adults aged 40-59 years, but then increased in older adults to 7.0 d. In all age groups, most infections were asymptomatic. Only high parasitaemias were significantly associated with fever; 3 clinical malaria attacks due to P. ovale were seen during the study period.
Juan Cuadros-gonzález - One of the best experts on this subject based on the ideXlab platform.
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Prospective comparative multi-centre study on imported Plasmodium ovale wallikeri and Plasmodium ovale curtisi infections.
Malaria journal, 2018Co-Authors: Gerardo Rojo-marcos, José Miguel Rubio-muñoz, Andrea Angheben, Stéphane Jauréguiberry, Silvia García-bujalance, Lina Rachele Tomasoni, Natalia Rodriguez-valero, José Manuel Ruiz-giardín, Joaquín Salas-coronas, Juan Cuadros-gonzálezAbstract:Few previous retrospective studies suggest that Plasmodium ovale wallikeri seems to have a longer latency period and produces deeper thrombocytopaenia than Plasmodium ovale curtisi. Prospective studies were warranted to better assess interspecies differences. Patients with imported P. ovale spp. infection diagnosed by thick or thin film, rapid diagnostic test (RDT) or polymerase chain reaction (PCR) were recruited between March 2014 and May 2017. All were confirmed by DNA isolation and classified as P. o. curtisi or P. o. wallikeri using partial sequencing of the ssrRNA gene. Epidemiological, analytical and clinical differences were analysed by statistical methods. A total of 79 samples (35 P. o. curtisi and 44 P. o. wallikeri) were correctly genotyped. Males predominate in wallikeri group (72.7%), whereas were 48.6% in curtisi group. Conversely, 74.3% of curtisi group were from patients of African ethnicity, whilst 52.3% of Caucasians were infected by P. o. wallikeri. After performing a multivariate analysis, more thrombocytopaenic patients (p = 0.022), a lower number of platelets (p = 0.015), a higher INR value (p = 0.041), and shorter latency in Caucasians (p = 0.034) were significantly seen in P. o. wallikeri. RDT sensitivity was 26.1% in P. o. curtisi and 42.4% in P. o. wallikeri. Nearly 20% of both species were diagnosed only by PCR. Total bilirubin over 3 mg/dL was found in three wallikeri cases. Two patients with curtisi infection had haemoglobin under 7 g/dL, one of them also with icterus. A wallikeri patient suffered from haemophagocytosis. Chemoprophylaxis failed in 14.8% and 35% of curtisi and wallikeri patients, respectively. All treated patients with various anti-malarials which included artesunate recovered. Diabetes mellitus was described in 5 patients (6.32%), 4 patients of wallikeri group and 1 curtisi. Imported P. o. wallikeri infection may be more frequent in males and Caucasians. Malaria caused by P. o. wallikeri produces more thrombocytopaenia, a higher INR and shorter latency in Caucasians and suggests a more pathogenic species. Severe cases can be seen in both species. Chemoprophylaxis seems less effective in P. ovale spp. infection than in P. falciparum, but any anti-malarial drug is effective as initial treatment. Diabetes mellitus could be a risk factor for P. ovale spp. infection.
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Infección por Plasmodium ovale: descripción de 16 casos y revisión del tema
Enfermedades infecciosas y microbiologia clinica, 2011Co-Authors: Gerardo Rojo-marcos, Juan Cuadros-gonzález, Peña Gómez-herruz, Luis Gete-garcía, Montserrat López-rubio, Gema Esteban-gutierrezAbstract:Introduction: Information on imported malaria caused by Plasmodium ovale parasite is scarce. Methods: Sixteen cases were studied retrospectively. Results: Most cases had an incubation period ranging from 2 to 53 months and were African immigrants recently arrived or residents in Spain who had visited West Africa. Ten patients had underlying diseases and 5 suffered from a previous P. falciparum infection. Three patients had severe complications and 3 were asymptomatic. Rapid malaria test was positive in 2 out of 10 patients. Five were diagnosed only with PCR. Conclusions: P. ovale infection can be asymptomatic or cause severe complications up to 5 years after
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Acute respiratory distress syndrome in a case of Plasmodium ovale malaria.
The American journal of tropical medicine and hygiene, 2008Co-Authors: Gerardo Rojo-marcos, Juan Cuadros-gonzález, José María Mesa-latorre, Ana María Culebras-lópez, Raúl De Pablo-sánchezAbstract:Acute respiratory distress syndrome is a well-known complication in Plasmodium falciparum infection. It is less frequently described in Plasmodium vivax, and only one case is reported in Plasmodium ovale. Here we present the second description of this pulmonary complication in a P. ovale acute infection.