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ABSTRACT This study reports a challenging diagnosis of Plasmodium ovale malaria in a Colombian citizen returning from Cameroon. Initial microscopy screenings conducted at two private hospitals yielded conflicting results, with the first showing negative smears and the second diagnosing P. vivax. Subsequent microscopy examinations at two government laboratories identified P. ovale, although the routine species-specific PCR strategy was negative. PCR confirmation was finally obtained when P. ovale wallikeri primers were used. Although P. ovale is not frequently found in Colombia, there is a clear need to include both P. ovale curtisi and P. ovale wallikeri in the molecular diagnostic strategy. Such need stems primarily from their extended latency period, which affects travelers, the increasing number of African migrants, and the importance of accurately mapping the distribution of Plasmodium species in Colombia.
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Objective To analyze the epidemiological characteristics of imported cases with Plasmodium ovale infections in Jiangsu Province from 2012 to 2020, so as to provide insights into the development of the imported malaria control strategy in the province. Methods All data pertaining to cases with definitive diagnosis of P. ovale malaria in Jiangsu Province from 2012 to 2020 were captured from the National Notifiable Disease Report System and the Information Management System for Parasitic Disease Control in China, including the date of going abroad and returning to China, time of malaria infections overseas, date of malaria onset, initial diagnosis and definitive diagnosis. All data pertaining to epidemic status were descriptively analyzed. Results A total of 347 cases of P. ovale malaria were reported in Jiangsu Province from 2012 to 2020, with the highest number seen in 2015 (71 cases). All cases were laboratory-confirmed overseas imported malaria cases, accounting for 14.32% of all reported malaria cases in Jiangsu Province during the period from 2012 to 2020. The 5 cities with the highest number of imported P. ovale malaria cases included Lianyungang City (53 cases, 15.27%), Nantong City (44 cases, 12.68%), Huai’an (44 cases, 12.68%), Taizhou City (44 cases, 12.68%) and Yangzhou City (36 cases, 10.37%). The highest number of imported P. ovale malaria cases was reported in October (39 cases, 11.24%), and the lowest number was seen in December (21 cases, 6.05%). P. ovale infections mainly occurred in were Equatorial Guinea (97 cases, 37.95%), Angola (60 cases, 17.29%) and Nigeria (40 cases, 11.53%). The median duration between returning to China and malaria onset was 64 (144) days, and 7.49% (26/347) of all cases developed malaria one year after returning to China. The initial diagnosis of P. ovale malaria was mainly made at county-level medical institutions (117 cases, 33.72%), and the definitive diagnosis was mainly made at city-level medical institutions (122 cases, 35.16%). The correct rate of initial diagnosis of P. ovale malaria increased from 0 in 2012 to 78.26% in 2020, appearing a tendency towards a rise year by year (χ2 = 50.90, P < 0.01). Conclusions Imported P. ovale malaria cases were reported in Jiangsu Province each year from 2012 to 2020, and P. ovale infections predominantly occurred in Africa. Initial and definitive diagnoses of P. ovale malaria were mainly made at city- and county-level medical institutions. Training on the detection ability of malaria parasites is recommended among grassroots microscopists to improve the diagnostic ability of P. ovale malaria, and consolidate the achievements of malaria elimination in Jiangsu Province.
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@#Malaria and dengue are among the most important public health threats in Malaysia. These two-arthropod borne diseases have overlapping mosquito biotopes and clinical manifestations, and co-infections have been associated with increased severity notably on the haematological abnormalities. Dengue caused by four dengue virus (DENV) serotypes has been highly endemic in Malaysia. However, malaria due to Plasmodium ovale (P. ovale) has been rarely reported among Malaysian population. Nonetheless, climate change and increased influx of international travellers and migrants have shifted the parasite boundaries to non-endemic countries. Thus, diagnosis and management of imported malarial infections should rely on the geographical knowledge on the origin of potential Plasmodium species, prompt laboratory testing and public health intervention. Moreover, it would be difficult to clinically differentiate dengue fever (DF) with a potential relapse or partially treated case of P. ovale, and there is absolutely no transmission of this Plasmodium species in our country. Hence, we believed that this case deserved to be reported.
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Mixed-species malaria infections are often unrecognized or underestimated. We hereby report the first described case of mixed infection with Plasmodium falciparum and Plasmodium ovale malaria in a returned traveller in Korea. In August 2016, a 25-year-old returned traveller from Cameroon and Democratic Republic of Congo presented with fever. He was diagnosed as P. falciparum malaria and successfully treated with artesunate. And 5 weeks after the completion of treatment, he presented with fever and diagnosed as P. ovale infection. P. ovale infection is a rare cause of malaria and often shows delayed presentation due to its dormant liver stage as hypnozoites. At re-presentation, the immunochromatographic test and microscopic examinations of our patient did not reveal P. ovale, which was only detected via polymerase chain reaction (PCR) assay. This case highlights the importance of considering malaria infection even in persons who have previously received malaria treatment. It also shows the usefulness of PCR testing for diagnosing P. ovale infections, which often present with a low level of parasitaemia.
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Adulto , Humanos , Camerún , Coinfección , Congo , Fiebre , Corea (Geográfico) , Hígado , Malaria , Plasmodium falciparum , Plasmodium ovale , Plasmodium , Reacción en Cadena de la PolimerasaRESUMEN
Objective To identify 10 imported cases of Plasmodium ovale wallikeri infection in Sichuan Province from January to April in 2018, and to analyze the P. ovale wallikeri infection status of 1 079 malaria cases reported in this area from 2013 to 2017. Methods The 10 cases collected in 2018 were examined by microscopy, RDT, nested PCR and sequencing. Meanwhile, the retrospective detections of P. ovale wallikeri of the 1 079 blood samples from past 5 years were conducted by nested PCR using wallikeri-specific primers. Results For the 10 cases, the microscopic examinations were all positive for P. ovale, of which 2 were mixed infection with P. falciparum, and the results of RDT were all positive for Plasmodium. Except for 2 cases of P. falciparum infection, the routine nested PCR showed negative results for rest of the samples. The nested PCR for the specific detection of P. ovale wallikeri showed the 10 cases were all positive, and the following sequencing confirmed that the 10 cases were all infected with P. ovale wallikeri. The retrospective tests discovered 2 cases both reported in 2017 and recorded as simple P. falciparum infection tuned out to be mixed infection with P. falciparum and P. ovale wallikeri. Conclusion This is the first time that imported P. ovale wallikeri infection is founded in Sichuan Province.
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Objective To identify 10 imported cases of Plasmodium ovale wallikeri infection in Sichuan Province from January to April in 2018, and to analyze the P. ovale wallikeri infection status of 1 079 malaria cases reported in this area from 2013 to 2017. Methods The 10 cases collected in 2018 were examined by microscopy, RDT, nested PCR and sequencing. Meanwhile, the retrospective detections of P. ovale wallikeri of the 1 079 blood samples from past 5 years were conducted by nested PCR using wallikeri-specific primers. Results For the 10 cases, the microscopic examinations were all positive for P. ovale, of which 2 were mixed infection with P. falciparum, and the results of RDT were all positive for Plasmodium. Except for 2 cases of P. falciparum infection, the routine nested PCR showed negative results for rest of the samples. The nested PCR for the specific detection of P. ovale wallikeri showed the 10 cases were all positive, and the following sequencing confirmed that the 10 cases were all infected with P. ovale wallikeri. The retrospective tests discovered 2 cases both reported in 2017 and recorded as simple P. falciparum infection tuned out to be mixed infection with P. falciparum and P. ovale wallikeri. Conclusion This is the first time that imported P. ovale wallikeri infection is founded in Sichuan Province.
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Objective To analyze the laboratory diagnosis results and epidemiological characteristics of imported malaria cases in Chongqing Municipality in 2015. Methods According to the Standard Operating Procedures of Malaria Diagnosis Ref-erence Laboratory Manual,all the blood samples collected from the imported malaria patients were detected by microscopy, RDT and nest PCR. Meanwhile,the epidemiological data of the malaria cases were collected from the Parasitic Diseases Informa-tion Management System and analyzed. Results Totally 31 cases of imported malaria were reported in Chonqing Municipality in 2015,among which,there were 2 vivax malaria cases(6.45%),23 falciparum malaria cases(74.19%),5 ovale malaria cas-es(16.13%),1 malariae malaria case(3.22%). For the 5 ovale cases,three of them were confirmed as Plasmodium ovale wal-likeri infection. Among all the cases,30 cases(96.77%)were from African countries,1(3.33%)was from Southeast Asia. Thir-ty patients were male,and 1 was female. All the patients were aged from 23-61 years. There was no obvious seasonality in the case distribution. Both the medians of duration from malaria attack to first visiting a doctor and from first visiting a doctor to diag-nosis were 2 days. The medical care units that the patients first visited were mainly county-level units,while those that made the diagnosis were mainly provincial level institutes. Conclusions All the malaria cases in Chongqing in 2015 are imported,no lo-cal cases have been found,which suggests that this municipality still maintain the malaria elimination state. However,the moni-toring and management of imported malaria cases as well as the training on malaria control for related medical staff still need to be strengthened.
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Objective To optimize the application of the nested PCR method for the detection of malaria according to the working practice,so as to improve the efficiency of malaria detection. Methods Premixing solution of PCR,internal primers for further amplification and new designed primers that aimed at two Plasmodium ovale subspecies were employed to optimize the reaction system,reaction condition and specific primers of P. ovale on basis of routine nested PCR. Then the specificity and the sensitivity of the optimized method were analyzed. The positive blood samples and examination samples of malaria were detected by the routine nested PCR and the optimized method simultaneously,and the detection results were compared and analyzed. Re-sults The optimized method showed good specificity,and its sensitivity could reach the pg to fg level. The two methods were used to detect the same positive malarial blood samples simultaneously,the results indicated that the PCR products of the two methods had no significant difference,but the non-specific amplification reduced obviously and the detection rates of P. ovale subspecies improved,as well as the total specificity also increased through the use of the optimized method. The actual detection results of 111 cases of malarial blood samples showed that the sensitivity and specificity of the routine nested PCR were 94.57％and 86.96％,respectively,and those of the optimized method were both 93.48％,and there was no statistically significant dif-ference between the two methods in the sensitivity(P>0.05),but there was a statistically significant difference between the two methods in the specificity(P<0.05). Conclusion The optimized PCR can improve the specificity without reducing the sensi-tivity on the basis of the routine nested PCR,it also can save the cost and increase the efficiency of malaria detection as less ex-periment links.
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Objective To diagnose the first imported case of Plasmodium ovale infection by laboratory detection. Meth?ods The epidemiological data and blood samples of the case were collected,and the samples were detected by the microscopic examination,rapid diagnostic test(RDT)and nested PCR. Results The patient was a construction worker backing from Con?go,Africa. He experienced the symptoms of irregular fever and weakness one month after returning in Lingyang Town,Junxian County. The results of RDT only suggested no?Plasmodium falciparum infection. Under the microscope,it was seen that the in?fected RBC were obviously disfigured and in irregular shape,the ring forms were thick and big,and also thick granulas in big trophozoite stage and schizont stage were found. The results of PCR showed that the size of amplified product was about 800 bp, which was conformed to that of P. ovale. Conclusion Though microscopic examination is the golden standard for malaria diag?nosis,as P. ovale is difficult to be identified under microscope,the microscopic method combined with PCR test can be used for definite diagnosis.
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Malaria remains a serious public health problem in Shandong Province, China; therefore, it is important to explore the characteristics of the current malaria prevalence situation in the province. In this study, data of malaria cases reported in Shandong during 2012-2014 were analyzed, and Plasmodium species were confirmed by smear microscopy and nested-PCR. A total of 374 malaria cases were reported, 80.8% of which were reported from 6 prefectures. Of all cases, P. falciparum was dominant (81.3%), followed by P. vivax (11.8%); P. ovale and P. malariae together accounted for 6.4% of cases. Notably, for the first time since 2012, no indigenous case had been reported in Shandong Province, a situation that continued through 2014. Total 95.2% of cases were imported from Africa. The ratio of male/female was 92.5:1, and 96.8% of cases occurred in people 20-54 years of age. Farmers or laborers represented 77.5% of cases. No significant trends of monthly pattern were found in the reported cases. All patients were in good condition after treatment, except for 3 who died. These results indicate that imported malaria has increased significantly since 2012 in Shandong Province, especially for P. falciparum, and there is an emergence of species diversity.
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Humanos , África , China , Agricultores , Malaria , Microscopía , Plasmodium falciparum , Plasmodium malariae , Plasmodium ovale , Plasmodium vivax , Plasmodium , Prevalencia , Salud PúblicaRESUMEN
En países donde el Plasmodium ovale no es común, los microscopistas tienden a identificarlo de manera errónea como Plasmodium vivax. En este trabajo reportamos la identificación de la especie P. ovale curtisi por el método de PCR múltiple semianidada (SnM-PCR) y la secuenciación de la subunidad pequeña del gen del ARN 18S, en un paciente paraguayo de 44 años de edad que vino en el 2.013 de Guinea Ecuatorial, África Occidental, a quien se le diagnosticó una infección por P. vivax por microscopía convencional. El empleo de métodos moleculares para la identificación de casos importados de infección con especies del género Plasmodium es uno de los objetivos principales en el control y la prevención de la malaria en Paraguay, teniendo en cuenta que el país se encuentra en fase de pre-eliminación de la enfermedad.
In countries where Plasmodium ovale is not common, the microscopists often mistakenlyidentify it as Plasmodium vivax. Here, we report the identification of the specie P. ovalecurtisi by the Seminested Multiplex PCR (SnM-PCR) technique and sequencing of the 18ssuRNA gene in a 44-year old Paraguayan male who came in 2013 from the EquatorialGuinea, Western Africa, and was diagnosed as having P. vivax infection by conventionalmicroscopy. Molecular biology tools for the identification of imported cases of infectionwith species of the genus Plasmodium is one of the main goals in the control andprevention of malaria in Paraguay, considering that the country is in the pre-eliminationphase of the disease.
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Humanos , Masculino , Adulto , Malaria/diagnóstico , Plasmodium ovaleRESUMEN
Background: Rapid diagnostic tests (RDTs) are used widely in the diagnosis of malaria. Although the effectiveness of RDTs for malaria has been described in many previous studies, the low performance of RDT particularly for <i>Plasmodium ovale</i> malaria in traveller has rarely been reported. Methods: This was a retrospective cohort study conducted on Japanese travellers diagnosed with malaria at the National Center for Global Health and Medicine between January 2004 and June 2013. The diagnosis of malaria was confirmed by microscopic examination, RDT, and polymerase chain reaction in all patients. The RDTs used in our study were Binax NOW Malaria (Binax Inc., Scarborough, Maine, USA) (BN) and SD Malaria Antigen Pf/Pan (Standard Diagnostics Inc., Korea) (SDMA). We compared the sensitivity of the RDTs to <i>P. ovale</i> malaria and <i>Plasmodium vivax</i> malaria. Results: A total of 153 cases of malaria were observed, 113 of which were found among Japanese travellers. Nine patients with <i>P. ovale</i> malaria and 17 patients with <i>P. vivax</i> malaria undergoing RDTs were evaluated. The overall sensitivity of RDTs for <i>P. ovale</i> malaria and <i>P. vivax</i> malaria was 22.2% and 94.1%, respectively (P < 0.001). The sensitivity of SDMA for <i>P. ovale</i> malaria and <i>P. vivax</i> malaria was 50% and 100%, respectively. The sensitivity of BN for <i>P. vivax</i> malaria was 90.0%, but it was ineffective in detecting the cases of <i>P. ovale</i> malaria. Conclusions: The sensitivity of RDTs was not high enough to diagnose <i>P. ovale</i> malaria in our study. In order not to overlook <i>P. ovale</i> malaria, therefore, microscopic examination is indispensable.
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Background: Rapid diagnostic tests (RDTs) have widely been used in the diagnosis of malaria. Although the effectiveness of RDTs for malaria has previously been described in many reports, the low performance of RDTs particularly for <i>Plasmodium ovale</i> malaria in travellers have rarely been reported. Methods: This was retrospective cohort study conducted among Japanese travellers who were diagnosed with malaria at the National Center for Global Health and Medicine between January 2004 and June 2013. Diagnosis of malaria by microscopic examination, RDT, and polymerase chain reaction were performed for all the patients. The RDTs used in our study were Binax NOW Malaria (Binax Inc., Scarborough, Maine, USA) (BN) and SD Malaria Antigen Pf/Pan (Standard Diagnostics Inc., Korea) (SDMA). We compared the sensitivity of the RDTs of <i>P. ovale</i> malaria with that of <i>Plasmodium vivax</i> malaria. Results: A total of 153 cases of malaria were observed, of which 113 patients were Japanese travellers. Nine patients with <i>P. ovale</i> malaria and 17 patients with <i>P. vivax</i> malaria performing RDTs were evaluated. The overall sensitivity of RDTs for <i>P. ovale</i> malaria was 22.2% and that for <i>P. vivax</i> malaria was 94.1% (P < 0.001). The sensitivity of SDMA for <i>P. vivax</i> malaria was 100% and that for <i>P. ovale</i> malaria was 50%. The sensitivity of BN for <i>P. vivax</i> malaria was 90.0%; however, it was unable to detect the cases of <i>P. ovale</i> malaria. Conclusions: The sensitivity of RDTs was not high enough to diagnose <i>P. ovale</i> malaria in our study. Thus, microscopic examination is indispensable not to overlook <i>P. ovale</i> malaria.
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Malaria is a parasitic infection caused by Plasmodium species. Most of the imported malaria in Korea are due to Plasmodium vivax and Plasmodium falciparum, and Plasmodium ovale infections are very rare. Here, we report a case of a 24-year-old American woman who acquired P. ovale while staying in Ghana, West Africa for 5 months in 2010. The patient was diagnosed with P. ovale malaria based on a Wright-Giemsa stained peripheral blood smear, Plasmodium genus-specific real-time PCR, Plasmodium species-specific nested PCR, and sequencing targeting 18S rRNA gene. The strain identified had a very long incubation period of 19-24 months. Blood donors who have malaria with a very long incubation period could be a potential danger for propagating malaria. Therefore, we should identify imported P. ovale infections not only by morphological findings but also by molecular methods for preventing propagation and appropriate treatment.
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Femenino , Humanos , Adulto Joven , Sangre/parasitología , ADN Protozoario/química , Ghana , Corea (Geográfico) , Malaria/diagnóstico , Microscopía , Plasmodium ovale/aislamiento & purificación , Reacción en Cadena de la Polimerasa , ARN Ribosómico 18S/genética , Análisis de Secuencia de ADN , ViajeRESUMEN
In contrast to the gradual reduction in the number of locally transmitted malaria cases in China, the number of imported malaria cases has been increasing since 2008. Here, we report a case of a 39-year-old Chinese man who acquired Plasmodium ovale wallikeri infection while staying in Ghana, West Africa for 6 months in 2012. Microscopic examinations of Giemsa-stained thin and thick blood smears indicated Plasmodium vivax infection. However, the results of rapid diagnostic tests, which were conducted 3 times, were not in agreement with P. vivax. To further check the diagnosis, standard PCR analysis of the small-subunit rRNA gene was conducted, based on which a phylogeny tree was constructed. The results of gene sequencing indicated that this malaria is a variant of P. ovale (P. ovale wallikeri). The infection in this patient was not a new infection, but a relapse of the infection from the one that he had contracted in West Africa.
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Adulto , Humanos , Masculino , Colorantes Azulados , Secuencia de Bases , China , ADN Protozoario/química , ADN Ribosómico/química , Ghana , Malaria/diagnóstico , Datos de Secuencia Molecular , Filogenia , Plasmodium ovale/clasificación , Reacción en Cadena de la Polimerasa , Recurrencia , Análisis de Secuencia de ADN , ViajeRESUMEN
In Korea, the majority of imported malaria cases are Plasmodium vivax and P. falciparum, but Plasmodium ovale cases are rarely reported. We describe an imported case of P. ovale that was confirmed by peripheral blood smear and nested PCR targeting the small subunit ribosomal RNA (SSU rRNA) gene. A 37-yr-old male had visited the Republic of Ghana in tropical West Africa 3 months ago, and suffered from fever and headache since 2 weeks after his return to Korea. The results of rapid malaria test using SD Malaria Antigen/Antibody Kit (Standard Diagnostics, Korea) were negative, but Plasmodium species was observed in Wright-Giemsa-stained peripheral blood smear. For the evaluation of possible mixed infection and identification of species, we performed a nested PCR targeting the SSU rRNA gene. P. ovale single infection was confirmed by PCR. The sequence analysis of the P. ovale SSU rRNA gene showed that our isolate was P. ovale classic type. We should confirm P. ovale infection for an accurate diagnosis and treatment of imported malaria cases in Korea because the number of travelers to P. ovale-endemic regions has recently increased.
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Humanos , Masculino , África Occidental , Coinfección , Fiebre , Genes de ARNr , Ghana , Cefalea , Corea (Geográfico) , Malaria , Plasmodium , Plasmodium ovale , Plasmodium vivax , Reacción en Cadena de la Polimerasa , ARN Ribosómico , Análisis de SecuenciaRESUMEN
There have been reports in Korea of imported malaria cases of four Plasmodium species, but there has been no report of imported Plasmodium ovale malaria confirmed by molecular biological methods. We report an imported case of that was confirmed by Wright-Giemsa-stained peripheral blood smear and nested polymerase chain reaction targeting the small subunit ribosomal RNA gene. The amplified DNA was sequenced and compared with other registered P. ovale isolates. The isolate in this study was a member of the classic type group. The patient was a 44-yr-old male who had worked as a woodcutter in Cote d'Ivoire in tropical West Africa. He was treated with hydroxychloroquine and primaquine and discharged following improvement. In conclusion, P. ovale should be considered as an etiology in the imported malaria in Korea, because the number of travelers to P. ovale endemic regions has recently increased.
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Masculino , Humanos , Adulto , Análisis de Secuencia de ADN , Reacción en Cadena de la Polimerasa , Plasmodium ovale/genética , Malaria/diagnóstico , Genes de ARNrRESUMEN
Liver function tests were performed in 61 vivax, 54 malariae and 15 ovale malaria patients who were admitted to Bangkok Hospital for Tropical Diseases between 2001 and 2004. The objective of the study was to evaluate changes in hepatic biochemical indices before and after treatment with artemisinin derivatives. On admission and prior to treatment, hepatic dysfunction was found among the 3 groups. Serum liver function tests and physical examinations were performed weekly during the 28-day follow-up period. Initially elevated serum bilirubin and diminished albumin returned to normal within 2 weeks of treatment. Serum alkaline phosphatase and aminotransferases returned to within normal limits within 3 weeks. We conclude that patients with Plasmodium vivax, P. malariae and P. ovale infections had slightly elevated serum bilirubin, aminotransferase and alkaline phosphatase levels, and hypoalbuminemia. These minor abnormalities returned to normal within a few weeks after treatment with therapies based on artemisinin derivatives.
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Persona de Mediana Edad , Masculino , Humanos , Femenino , Animales , Adulto , Adolescente , Resultado del Tratamiento , Sesquiterpenos/uso terapéutico , Albúmina Sérica , Plasmodium vivax/efectos de los fármacos , Plasmodium ovale/efectos de los fármacos , Plasmodium malariae/efectos de los fármacos , Malaria Vivax/tratamiento farmacológico , Malaria/tratamiento farmacológico , Pruebas de Función Hepática , Hígado/fisiopatología , Bilirrubina/sangre , Artemisininas/uso terapéutico , Antiinfecciosos/uso terapéutico , Alanina Transaminasa/sangreRESUMEN
A plasmodium ovale-like organism occurring in the blood of a native Filipino is reported. If this is actually a Plasmodium ovale infection it will be its second appearance in the Philippines. The morphology of the parasite is briefly described and some specific diagnosis points are given. (Summary)