Malaria is a tropical disease caused by protozoans of the Plasmodium genus. Delayed diagnosis and misdiagnosis are strongly associated with higher mortality. In recent years, a greater importance is attributed to Plasmodium knowlesi, a species found mainly in Southeast Asia. Routine parasitological diagnostics are associated with certain limitations and difficulties in unambiguous determination of the parasite species based only on microscopic image. Recently, molecular techniques have been increasingly used for predictive diagnosis. The aim of the study is to draw attention to the risk of travelling to knowlesi malaria endemic areas and to raise awareness among personnel involved in the therapeutic process.
Asia, Southeastern ; Global Health ; Humans ; Malaria/diagnosis/*epidemiology/*parasitology ; Microscopy/methods ; Molecular Diagnostic Techniques/methods ; Plasmodium knowlesi/*isolation & purification ; Public Health

No abstract available.
Adult ; Anti-Bacterial Agents/therapeutic use ; Antimalarials/therapeutic use ; Clindamycin/therapeutic use ; Female ; Humans ; Malaria, Vivax/*diagnosis/drug therapy/parasitology ; Neutrophils/*parasitology ; Plasmodium vivax/growth & development/*isolation & purification ; Pregnancy ; Quinine/therapeutic use ; Trophozoites/cytology

While imported falciparum malaria has been increasingly reported in recent years in Korea, clinicians have difficulties in making a clinical diagnosis as well as in having accessibility to effective anti-malarial agents. Here we describe an unusual case of imported falciparum malaria with severe hemolytic anemia lasting over 2 weeks, clinically mimicking a coinfection with babesiosis. A 48-year old Korean man was diagnosed with severe falciparum malaria in France after traveling to the Republic of Benin, West Africa. He received a 1-day course of intravenous artesunate and a 7-day course of Malarone (atovaquone/proguanil) with supportive hemodialysis. Coming back to Korea 5 days after discharge, he was readmitted due to recurrent fever, and further treated with Malarone for 3 days. Both the peripheral blood smears and PCR test were positive for Plasmodium falciparum. However, he had prolonged severe hemolytic anemia (Hb 5.6 g/dl). Therefore, 10 days after the hospitalization, Babesia was considered to be potentially coinfected. A 7-day course of Malarone and azithromycin was empirically started. He became afebrile within 3 days of this babesiosis treatment, and hemolytic anemia profiles began to improve at the completion of the treatment. He has remained stable since his discharge. Unexpectedly, the PCR assays failed to detect DNA of Babesia spp. from blood. In addition, during the retrospective review of the case, the artesunate-induced delayed hemolytic anemia was considered as an alternative cause of the unexplained hemolytic anemia.
Anemia, Hemolytic/chemically induced/*etiology/*pathology ; Anti-Bacterial Agents/therapeutic use ; Antimalarials/therapeutic use ; Artemisinins/adverse effects/therapeutic use ; Atovaquone/therapeutic use ; Azithromycin/therapeutic use ; Babesiosis/complications/*diagnosis/drug therapy/*pathology ; Benin ; Blood/parasitology ; Coinfection/diagnosis/pathology ; Drug Combinations ; France ; Humans ; Korea ; Malaria, Falciparum/complications/*diagnosis/drug therapy/*pathology ; Male ; Middle Aged ; Plasmodium falciparum/*isolation & purification ; Proguanil/therapeutic use ; Travel ; Treatment Outcome

Malaria is endemic across lowland Papua New Guinea (PNG) and case management has been based on symptomatic diagnosis and presumptive treatment of fever cases with an antimalarial. This study aimed to investigate the prevalence of malaria infection among fever cases presenting to 5 purposely selected sentinel health facilities in order to estimate the proportion of patients requiring antimalarial drugs. A total of 1807 fever patients were screened. Overall, 45% of fever patients had a positive malaria blood slide; 35% were infected with Plasmodium falciparum, 9% with P. vivax and 2% with P. malariae. Slide positivity was highest in Dreikikir (75%) and lowest in Wipim (2%). Among patients aged 1-4 years, 22% had moderate to severe anaemia (Hb < 8 g/dI) and 21% of children 2-9 years of age showed signs of splenomegaly (Hackett score 1-5). Comorbidity differed significantly between study sites and was not closely correlated with malaria infection. Clinical diagnosis by health facility staff was malaria for 67% of all fever cases, including 89% of slide-positive and 48% of slide-negative patients. 70% of rapid diagnostic test-negative cases were treated with an antimalarial. It is estimated that due to the lack of parasitological diagnosis the selected health facilities reported an excess of 18% (Dreikikir) to 98% (Wipim) malaria patients on average each month. In consideration of the significant differences in malaria-attributable fevers between study sites, the implementation of parasitological diagnosis in health facilities and administration of antimalarials only to test-positive patients has the potential to significantly improve the management of fever cases and reporting of malaria. A better tailoring to different settings may increase the effectiveness of malaria control interventions.
Adolescent ; Adult ; Child ; Child, Preschool ; Female ; Fever/*parasitology ; Humans ; Infant ; Malaria/complications/diagnosis/*epidemiology ; Male ; Papua New Guinea/epidemiology ; Young Adult

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.
Blood/parasitology ; DNA, Protozoan/chemistry/genetics ; Female ; Ghana ; Humans ; Korea ; Malaria/*diagnosis/parasitology/*pathology ; Microscopy ; Plasmodium ovale/*isolation & purification ; Polymerase Chain Reaction ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; *Travel ; Young Adult

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.
Adult ; Azure Stains ; Base Sequence ; China ; DNA, Protozoan/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Ghana ; Humans ; Malaria/*diagnosis/parasitology ; Male ; Molecular Sequence Data ; Phylogeny ; Plasmodium ovale/*classification/genetics/isolation & purification ; Polymerase Chain Reaction ; Recurrence ; Sequence Analysis, DNA ; Travel

Malaria, the most common vector-borne parasite infection worldwide, results from infection by Plasmodium species. Approximately 80% of malaria cases are caused by P. vivax, which is broadly distributed from tropical to temperate regions; P. falciparum is the second most common infectious species. P. malariae and P. ovale are responsible for a relatively small proportion of malaria cases. Here, we report the case of a 23-yr-old Korean woman who acquired a P. malariae infection while visiting the Republic of Ghana in West Africa for business. She was diagnosed with P. malariae malaria on the basis of peripheral blood smear (PBS) and species-specific conventional and real-time PCR assays for 18S rRNA. She was treated with hydroxychloroquine, and the resulting PBS examination on day 2 suggested that negative conversion occurred. At her 1-month follow-up, however, both the PBS examination and molecular test for malaria demonstrated recurrent parasitemia. We started rescue therapy with mefloquine, and the patient recovered successfully. This is an important finding suggesting possible late recrudescence of a chloroquine-resistant P. malariae strain identified not only by its morphological features, but also by molecular tests.
Antimalarials/therapeutic use ; Drug Resistance ; Female ; Humans ; Hydroxychloroquine/therapeutic use ; Malaria/*diagnosis/drug therapy/parasitology ; Mefloquine/therapeutic use ; Plasmodium malariae/genetics/*isolation & purification ; RNA, Ribosomal, 18S/genetics ; Real-Time Polymerase Chain Reaction ; Recurrence ; Young Adult

In Iran, Plasmodium vivax is responsible for more than 80% of the infected cases of malaria per year. Control interventions for vivax malaria in humans rely mainly on developed diagnostic methods. Recombinant P. vivax apical membrane antigen-1 (rPvAMA-1) has been reported to achieve designing rapid, sensitive, and specific molecular diagnosis. This study aimed to perform isolation and expression of a rPvAMA-1, derived from Iranian patients residing in an endemic area. Then, the diagnostic efficiency of the characterized Iranian PvAMA-1 was assessed using an indirect ELISA method. For this purpose, a partial region of AMA-1 gene was amplified, cloned, and expressed in pET32a plasmid. The recombinant His-tagged protein was purified and used to coat the ELISA plate. Antibody detection was assessed by indirect ELISA using rPvAMA-1. The validity of the ELISA method for detection of anti-P. vivax antibodies in the field was compared to light microscopy on 84 confirmed P. vivax patients and compared to 84 non-P. vivax infected individuals. The ELISA cut-off value was calculated as the mean+2SD of OD values of the people living in malaria endemic areas from a south part of Iran. We found a cut-off point of OD=0.311 that showed the best correlation between the sera confirmed with P. vivax infection and healthy control sera. A sensitivity of 81.0% and specificity of 84.5% were found at this cut off titer. A good degree of statistical agreement was found between ELISA using rPvAMA-1 and light microscopy (0.827) by Kappa analysis.
Antibodies, Protozoan/blood/immunology ; Antigens, Protozoan/*blood/genetics/immunology ; Diagnostic Tests, Routine/*methods ; Enzyme-Linked Immunosorbent Assay/*methods ; Female ; Humans ; Iran ; Malaria, Vivax/blood/*diagnosis/immunology/*parasitology ; Male ; Membrane Proteins/blood/genetics/immunology ; Plasmodium vivax/isolation & purification/*physiology ; Protozoan Proteins/blood/genetics/immunology ; Sensitivity and Specificity

Animals ; Apraxias ; congenital ; Cogan Syndrome ; diagnosis ; etiology ; Coma ; Diagnosis, Differential ; Humans ; Malaria, Cerebral ; complications ; diagnosis ; parasitology ; Male ; Middle Aged ; Plasmodium falciparum ; isolation & purification ; Tomography, X-Ray Computed

Parasitemia characteristics of Plasmodium vivax malaria in temperate regions may differ from those in tropical zones. However, most parasitological and clinical features of P. vivax malaria have been investigated in the latter. In this study, we investigated 383 malaria patients to clarify the parasitemia characteristics of a P. vivax strain in the Republic of Korea (ROK). The mean parasitemia (8,396/microL) was less than half of tropical P. vivax malaria, and multiple invasions of erythrocytes were not rare (53.5% of the patients, 2.4% of the total investigated RBCs), but less than the observations in tropical zones. The intervals between the first symptom onset and diagnosis were significantly longer in gametocyte (+) patients than in gametocyte (-) patients. Only half of the total patients had both genders of gametocytes (191 of 353), and the male gametocyte density (169/microL) was lower than that of P. vivax strains of a previous study. Multiple invasions of erythrocytes and gametocytemia were coincident factors of the degree of anemia in P. vivax malaria. The present findings demonstrate the P. vivax strain in ROK reveals relatively low parasitemia and low male to female gametocyte ratio. The low ratio may be related with low transmission efficacy.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Erythrocytes/parasitology ; Female ; Humans ; Malaria, Vivax/*diagnosis/epidemiology/parasitology ; Male ; Middle Aged ; Parasitemia/*diagnosis/epidemiology/parasitology ; Plasmodium vivax/isolation & purification ; Republic of Korea/epidemiology