In 2003, 2 small swidden field malaria outbreaks were identified in Tuong Duong district of Nghe An province. Although different development of the first time, malaria outbreaks developed in swiddenfield, then transmissed into villages. A lots of patients have confirmed to have malaria. One death case was caused by the late hospital admission. The number of working and overnight people on the swiddenfields increased at the hot spot time as this was the harvesting time and the school children had summer holiday and joined their parents’ work here (29.1 – 48.9% of household and 27.2-28.4% of population in the hamlets). They did not use mosquito nets. The infection rate of malaria among the swiddenfield people was 13.5 – 60.5% and 7.4 – 42.2%, respectively. The mass blood screen showed the presence of both P.falciparum and P.vivax (P.falciparum in Ang village and both P.falciparum and P.vivax in Phong village). A high malaria infected rate in 2 outbreaks showed a limited diagnosis and treatment’s quality of local health. Cold parasites were found to be high, with P.falciparum and combined form
Malaria ; epidemiology ; Malaria, Falciparum

OBJECTIVE: To examine the impact of COVID-19 pandemic on the epidemic status of imported malaria and national malaria control program in China, so as to provide insights into post-elimination malaria surveillance. METHODS: All data pertaining to imported malaria cases were collected from Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region during the period from January 1, 2018 through December 31, 2021. The number of malaria cases, species of malaria parasites, country where malaria parasite were infected, diagnosis and treatment after returning to China, and response were compared before (from January 1, 2018 to January 22, 2020) and after the COVID-19 pandemic (from January 23, 2020 to December 31, 2021). RESULTS: A total of 2 054 imported malaria cases were reported in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region during the period from January 1, 2018 to December 31, 2021, and there were 1 722 cases and 332 cases reported before and after the COVID-19 pandemic, respectively. All cases were reported within one day after definitive diagnosis. The annual mean number of reported malaria cases reduced by 79.30% in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region after the COVID-19 pandemic (171 cases) than before the pandemic (826 cases), and the number of monthly reported malaria cases significantly reduced in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region since February 2020. There was a significant difference in the constituent ratio of species of malaria parasites among the imported malaria cases in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region before and after the COVID-19 pandemic (χ² = 146.70, P < 0.05), and P. falciparum malaria was predominant before the COVID-19 pandemic (72.30%), while P. ovale malaria (44.28%) was predominant after the COVID-19 pandemic, followed by P. falciparum malaria (37.65%). There was a significant difference in the constituent ratio of country where malaria parasites were infected among imported malaria cases in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region before and after the COVID-19 pandemic (χ² = 13.83, P < 0.05), and the proportion of malaria cases that acquired Plasmodium infections in western Africa reduced after the COVID-19 pandemic that before the pandemic (44.13% vs. 37.95%; χ² = 4.34, P < 0.05), while the proportion of malaria cases that acquired Plasmodium infections in eastern Africa increased after the COVID-19 pandemic that before the pandemic (9.58% vs. 15.36%; χ² = 9.88, P = 0.02). The proportion of completing case investigation within 3 days was significantly lower after the COVID-19 pandemic than before the pandemic (96.69% vs. 98.32%; χ²= 3.87, P < 0.05), while the proportion of finishing foci investigation and response within 7 days was significantly higher after the COVID-19 pandemic than before the pandemic (100.00% vs. 98.43%; χ² = 3.95, P < 0.05). CONCLUSIONS The number of imported malaria cases remarkably reduced in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region of China during the COVID-19 pandemic, with a decreased proportion of completing case investigations within 3 days. The sensitivity of the malaria surveillance-response system requires to be improved to prevent the risk of secondary transmission of malaria due to the sharp increase in the number of imported malaria cases following the change of the COVID-19 containment policy.
Humans ; Pandemics ; China/epidemiology* ; Incidence ; COVID-19/epidemiology* ; Malaria/prevention & control* ; Malaria, Falciparum/epidemiology*

Merozoite surface proteins (MSPs) of malaria parasites play critical roles during the erythrocyte invasion and so are potential candidates for malaria vaccine development. However, because MSPs are often under strong immune selection, they can exhibit extensive genetic diversity. The gene encoding the merozoite surface protein-3 (MSP-3) of Plasmodium falciparum displays 2 allelic types, K1 and 3D7. In Thailand, the allelic frequency of the P. falciparum msp-3 gene was evaluated in a single P. falciparum population in Tak at the Thailand and Myanmar border. However, no study has yet looked at the extent of genetic diversity of the msp-3 gene in P. falciparum populations in other localities. Here, we genotyped the msp-3 alleles of 63 P. falciparum samples collected from 5 geographical populations along the borders of Thailand with 3 neighboring countries (Myanmar, Laos, and Cambodia). Our study indicated that the K1 and 3D7 alleles coexisted, but at different proportions in different Thai P. falciparum populations. K1 was more prevalent in populations at the Thailand-Myanmar and Thailand-Cambodia borders, whilst 3D7 was more prevalent at the Thailand-Laos border. Global analysis of the msp-3 allele frequencies revealed that proportions of K1 and 3D7 alleles of msp-3 also varied in different continents, suggesting the divergence of malaria parasite populations. In conclusion, the variation in the msp-3 allelic patterns of P. falciparum in Thailand provides fundamental knowledge for inferring the P. falciparum population structure and for the best design of msp-3 based malaria vaccines.
Antigens, Protozoan/*genetics ; *Gene Frequency ; *Genetic Variation ; Genotype ; Humans ; Malaria, Falciparum/epidemiology/*parasitology ; Plasmodium falciparum/classification/*genetics/isolation & purification ; Polymorphism, Genetic ; Protozoan Proteins/*genetics ; Thailand/epidemiology

Plasmodium falciparum liver stage antigen-1 (PfLSA-1) is one of the few antigens expressed exclusively in liver stage parasites. In this study, we evaluated the antibody responses against recombinant PfLSA-1 in naturally infected individuals in Myanmar. High levels of antibody responses (70.7%) were detected in 82 serum samples from 116 infected individuals, and IgG responses to PfLSA-1 principally composed of responses of IgG1 and IgG3 subclasses. These results show that PfLSA-1 elicits effective antibody responses in individuals infected with P. falciparum, and thus it could be not only an attractive candidate protein for vaccine development, but also a useful antigen for serodiagnosis of the infection.
Animals ; Antibodies, Protozoan/*blood/immunology ; Antigens, Protozoan/*immunology ; Humans ; Immunoglobulin G/blood ; Malaria, Falciparum/blood/epidemiology/*immunology ; Myanmar/epidemiology

We retrospectively examined the charts of travelers admitted to the Hospital for Tropical Diseases, Bangkok, Thailand, with malaria during the years 2000-2005. Twenty-one cases of malaria were identified, of which 12 (57%) were Plasmodium vivax infections and 9 (43%) were P. falciparum infections. There was one mixed case with vivax and falciparum infection. Only 1 P. falciparum case had complications. All cases were successfully treated with standard antimalarial drugs. Only 3 of the 21 cases were thought to be acquired in Thailand, the rest were regarded to be imported.
*Travel ; Thailand/epidemiology ; Retrospective Studies ; *Plasmodium vivax ; *Plasmodium falciparum ; Middle Aged ; Male ; Malaria/*epidemiology/*parasitology ; Humans ; Animals ; Adult

Hemoglobinopathy and malaria are commonly found worldwide particularly in malaria endemic areas. Thalassemia, the alteration of globin chain synthesis, has been reported to confer resistance against malaria. The prevalence of thalassemia was investigated in 101 malaria patients with Plasmodium falciparum and Plasmodium vivax along the Thai-Myanmar border to examine protective effect of thalassemia against severe malaria. Hemoglobin typing was performed using low pressure liquid chromatography (LPLC) and alpha-thalassemia was confirmed by multiplex PCR. Five types of thalassemia were observed in malaria patients. The 2 major types of thalassemia were Hb E (18.8%) and alpha-thalassemia-2 (11.9%). There was no association between thalassemia hemoglobinopathy and malaria parasitemia, an indicator of malaria disease severity. Thalassemia had no significant association with P. vivax infection, but the parasitemia in patients with coexistence of P. vivax and thalassemia was about 2-3 times lower than those with coexistence of P. falciparum and thalassemia and malaria without thalassemia. Furthermore, the parasitemia of P. vivax in patients with coexistence of Hb E showed lower value than coexistence with other types of thalassemia and malaria without coexistence. Parasitemia, hemoglobin, and hematocrit values in patients with coexistence of thalassemia other than Hb E were significantly lower than those without coexistence of thalassemia. Furthermore, parasitemia with coexistence of Hb E were 2 times lower than those with coexistence of thalassemia other than Hb E. In conclusion, the results may, at least in part, support the protective effect of thalassemia on the development of hyperparasitemia and severe anemia in malaria patients.
Female ; Hemoglobins/genetics/metabolism ; Humans ; Malaria, Falciparum/blood/complications/*genetics/parasitology ; Malaria, Vivax/blood/complications/*genetics/parasitology ; Male ; Middle Aged ; Plasmodium falciparum/physiology ; Plasmodium vivax/physiology ; Thailand/epidemiology ; Thalassemia/blood/complications/epidemiology/*genetics

The incidence of imported malaria has been increasing in Korea. We reviewed data retrospectively to evaluate the epidemiology, clinical features, and outcomes of imported malaria from 1995 to 2007 in a university hospital. All patients diagnosed with imported malaria were included. Imported malaria was defined as a positive smear for malaria that was acquired in a foreign country. A total of 49 patients (mean age, 35.7 year; M : F = 38 : 11) were enrolled. The predominant malarial species was Plasmodium falciparum (73.5%), and the most frequent area of acquisition was Africa (55.1%), followed by Southeast Asia (22.4%) and South Asia (18.4%). Fourteen-patients (30.6%) suffered from severe malaria caused by P. falciparum and 1 patient (2.0%) died of multiorgan failure. Most of the patients were treated with mefloquine (79.2%) or quinine (10.2%); other antimalarial agents had to be given in 13.2% treated with mefloquine and 44.4% with quinine due to adverse drug events (ADEs). P. falciparum was the most common cause of imported malaria, with the majority of cases acquired from Africa, and a significant number of patients had severe malaria. Alternative antimalarial agents with lower rates of ADEs might be considered for effective treatment instead of mefloquine and quinine.
Adult ; Animals ; Antimalarials/adverse effects/therapeutic use ; Female ; Humans ; Korea/epidemiology ; Malaria, Falciparum/drug therapy/epidemiology/*parasitology ; Male ; Middle Aged ; Plasmodium falciparum/drug effects/isolation & purification ; Retrospective Studies ; *Travel

Local malaria transmission in the United Arab Emirates (UAE) came to an end in 1997. Nevertheless, UAE has been subjected to substantial importation of malaria cases from abroad, concerning both UAE nationals and immigrants from malarious countries with a total number of 2,119 cases in 2007. To evaluate a new DNA extraction technique using nested PCR, blood samples were collected from 132 individuals who presented to Infectious Diseases Department in Rashid Hospital, Dubai, and Central Department of Malaria Control with fever and persistent headache. Giemsa-stained blood films and ELISA test for malaria antibodies were carried out for detection of Plasmodium infection. Plasmodium infections were identified with the genus-specific primer set and species differentiation using nested PCR. A rapid procedure for diagnosis of malaria infections directly from dried blood spots using for the first time DNA extract from FTA Elute cards was evaluated in contrast to extraction techniques using FTA classic cards and rapid boiling technique. Our new simple technique for DNA extraction using FTA Elute cards was very sensitive giving a sensitivity of 100% compared to 94% using FTA classic cards and 62% in the rapid boiling technique. No complex preparation of blood samples was required prior to the amplification. The production cost of DNA isolation in our PCR assay was much less in comparable to that of other DNA extraction protocols. The nested PCR detected plasmodial infection and could differentiate P. falciparum from P. vivax, and also detected the mixed infection.
Animals ; DNA, Protozoan/genetics/*isolation & purification ; *Emigrants and Immigrants/statistics & numerical data ; *Genetic Techniques ; Humans ; Malaria, Falciparum/epidemiology/*parasitology ; Plasmodium falciparum/genetics/*isolation & purification ; Polymerase Chain Reaction/*methods ; United Arab Emirates/epidemiology

Local malaria transmission in the United Arab Emirates (UAE) came to an end in 1997. Nevertheless, UAE has been subjected to substantial importation of malaria cases from abroad, concerning both UAE nationals and immigrants from malarious countries with a total number of 2,119 cases in 2007. To evaluate a new DNA extraction technique using nested PCR, blood samples were collected from 132 individuals who presented to Infectious Diseases Department in Rashid Hospital, Dubai, and Central Department of Malaria Control with fever and persistent headache. Giemsa-stained blood films and ELISA test for malaria antibodies were carried out for detection of Plasmodium infection. Plasmodium infections were identified with the genus-specific primer set and species differentiation using nested PCR. A rapid procedure for diagnosis of malaria infections directly from dried blood spots using for the first time DNA extract from FTA Elute cards was evaluated in contrast to extraction techniques using FTA classic cards and rapid boiling technique. Our new simple technique for DNA extraction using FTA Elute cards was very sensitive giving a sensitivity of 100% compared to 94% using FTA classic cards and 62% in the rapid boiling technique. No complex preparation of blood samples was required prior to the amplification. The production cost of DNA isolation in our PCR assay was much less in comparable to that of other DNA extraction protocols. The nested PCR detected plasmodial infection and could differentiate P. falciparum from P. vivax, and also detected the mixed infection.
Animals ; DNA, Protozoan/genetics/*isolation & purification ; *Emigrants and Immigrants/statistics & numerical data ; *Genetic Techniques ; Humans ; Malaria, Falciparum/epidemiology/*parasitology ; Plasmodium falciparum/genetics/*isolation & purification ; Polymerase Chain Reaction/*methods ; United Arab Emirates/epidemiology

OBJECTIVETo assess the distribution of ABO blood group and their relationship with Plasmodium falciparum (P. falciparum) malaria among febrile outpatients who sought medical attention at Dore Bafeno Health Center, Southern Ethiopia.

METHODSA total of 269 febrile outpatients who visited Dore Bafeno Health Center, Southern Ethiopia, were examined for malaria and also tested for ABO blood groups in January 2010. The blood specimens were collected by finger pricking, stained with Geimsa, and examined microscopically. Positive cases of the parasitemia were counted. CareStart™ Malaria Pf/Pv Combo was also used to test the blood specimens for malaria. ABO blood groups were determined by agglutination test using ERYCLONE(®) antisera. Data on socio-demographic characteristics and treatment status of the participants were also collected. Chi-square and ANOVA tests were used to assess the difference between frequencies and means, respectively.

RESULTSOut of a total of 269 participants, 178 (66.2%) febrile patients were found to be infected with Plasmodium parasites, among which 146 (54.3%), 28 (10.4%), and 4 (1.5%) belonged to P. falciparum, P. vivax, and mixed infections, respectively. All febrile patients were also tested for ABO blood groups and 51.3%, 23.5%, 21.9% and 3.3% were found to be blood types of O, A, B and AB, respectively. Both total malaria infection and P. falciparum infection showed significant association with blood types (P<0.05). The proportion of A or B but not O phenotypes was higher (P<0.05) in individuals with P. falciparum as compared with non-infected individuals. The chance of having P. falciparum infection in patients with blood groups A, B and AB was 2.5, 2.5 and 3.3 times more than individuals showing blood O phenotypes, respectively. The mean P. falciparum malaria parasitaemia for blood groups A, B, AB, and O were 3 744/µL, 1 805/µL, 5 331/µL, and 1 515/µL, respectively (P<0.01).

CONCLUSIONSThe present findings indicate that individuals of blood groups A, B and AB are more susceptible to P. falciparum infection as compared with individuals of blood group O. Nevertheless, further in depth studies are required to clearly establish the role that ABO blood group plays in P. falciparum malaria.

ABO Blood-Group System ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Blood ; parasitology ; Child ; Child, Preschool ; Cross-Sectional Studies ; Disease Susceptibility ; Ethiopia ; epidemiology ; Female ; Humans ; Infant ; Infant, Newborn ; Malaria, Falciparum ; epidemiology ; Male ; Microscopy ; Middle Aged ; Plasmodium falciparum ; isolation & purification ; Young Adult