-
China CDC Weekly Apr 2024Laiza and nearby areas (LNA) in Myanmar are identified as the primary malaria hotspots in the bordering regions of Yunnan Province, China.
INTRODUCTION
Laiza and nearby areas (LNA) in Myanmar are identified as the primary malaria hotspots in the bordering regions of Yunnan Province, China.
METHODS
Six sentinel surveillance sites were established at the China-Myanmar border in LNA to monitor malaria. Data from 2019 was used as a baseline to analyze malaria incidence and trends in LNA and Myanmar, as well as the importation of malaria cases into China from 2019 to 2023.
RESULTS
was the predominant species, representing 99.95% (14,060/14,066) of confirmed malaria cases in LNA. A total of 8,356 malaria cases were identified in 2023, with an annual parasite incidence (API) of 19.78 per 100 person-years. Compared to 2019, the incidence rate ratio was 21.47 (95% confidence interval: 18.84, 24.48), indicating that the API in 2023 was 21.47 times higher than that in 2019. In Yunnan, out of 1,016 reported cases, 545 imported cases (53.64%) originated from LNA and spread to 18 (13.95%) out of 129 counties. Ten provinces in China, including Yunnan, reported imported malaria cases from LNA in Myanmar.
CONCLUSIONS
The increase in population, particularly among internally displaced persons, along with inadequate healthcare services, has led to a notable resurgence of malaria in LNA. This resurgence poses a risk to preventing the re-emergence of malaria transmission in China. There is an urgent need for novel collaborative policies, as well as financial and technical assistance, to enhance malaria control efforts in LNA, Myanmar.
PubMed: 38737824
DOI: 10.46234/ccdcw2024.073 -
China CDC Weekly Apr 2024China's "1-3-7" approach outlines specific targets to guide and monitor the processes of case reporting, investigation, and response. However, few studies have examined...
WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?
China's "1-3-7" approach outlines specific targets to guide and monitor the processes of case reporting, investigation, and response. However, few studies have examined the time intervals preceding the initial step, and the timeline from the arrival of imported malaria cases in China to their diagnosis has been largely overlooked.
WHAT IS ADDED BY THIS REPORT?
The study demonstrated that the median duration from arrival in China to the onset of symptoms for was 78 days, with 71.59% of imported cases manifesting symptoms after more than one month. For , the median interval was 42 days, with 55.91% exceeding one month. Additionally, the median time from symptom onset to malaria treatment in China between 2014 and 2021 was 2 days, with an interquartile range (IQR) of 1-4 days.
WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE?
This study represents the initial effort to delineate the chronology of imported malaria cases, from their arrival in China to their subsequent treatment. The results underscore the importance of providing malaria health education to populations arriving from overseas. Furthermore, enhancing physician training is crucial for improving the diagnosis of malaria.
PubMed: 38737821
DOI: 10.46234/ccdcw2024.070 -
MalariaWorld Journal 2024causes the vast majority of malaria cases in Brazil. The lifecycle of this parasite includes a latent stage in the liver, the hypnozoite. Reactivation of hypnozoites...
causes the vast majority of malaria cases in Brazil. The lifecycle of this parasite includes a latent stage in the liver, the hypnozoite. Reactivation of hypnozoites induces repeated relapses. We report a case of two relapses of malaria in a teenage girl after conventional treatment with chloroquine and primaquine. Chloroquine prophylactic treatment for three months was prescribed with a favourable outcome of the case.
PubMed: 38737169
DOI: 10.5281/zenodo.11125657 -
Malaria Journal May 2024Despite continuous prevention and control strategies in place, malaria remains a major public health problem in sub-Saharan Africa including Ethiopia. Moreover,...
BACKGROUND
Despite continuous prevention and control strategies in place, malaria remains a major public health problem in sub-Saharan Africa including Ethiopia. Moreover, prevalence of malaria differs in different geographical settings and epidemiological data were inadequate to assure disease status in the study area. This study was aimed to determine the prevalence of malaria and associated risk factors in selected rural kebeles in South Ethiopia.
METHODS
A community-based cross-sectional study was conducted between February to June 2019 in eight malaria-endemic kebeles situated in four zones in South Ethiopia. Mult-stage sampling techniques were employed to select the study zones, districts, kebeles and households. Blood sample were collected from 1674 participants in 345 households by finger prick and smears were examined by microscopy. Sociodemographic data as well as risk factors for Plasmodium infection were collected using questionnaires. Bivariate and multivariate logistic regressions were used to analyse the data.
RESULTS
The overall prevalence of malaria in the study localities was 4.5% (76/1674). The prevalence was varied among the study localities with high prevalence in Bashilo (14.6%; 33/226) followed by Mehal Korga (12.1%; 26/214). Plasmodium falciparum was the dominant parasite accounted for 65.8% (50/76), while Plasmodium vivax accounted 18.4% (14/76). Co-infection of P. falciparum and P. vivax was 15.8% (12/76). Among the three age groups prevalence was 7.8% (27/346) in age less than 5 years and 7.5% (40/531) in 5-14 years. The age groups > 14years were less likely infected with Plasmodium parasite (AOR = 0.14, 95% CI 0.02-0.82) than under five children. Non-febrile individuals 1638 (97.8%) were more likely to had Plasmodium infection (AOR = 28.4, 95% CI 011.4-70.6) than febrile 36 (2.2%). Individuals living proximity to mosquito breeding sites have higher Plasmodium infection (AOR = 6.17, 95% CI 2.66-14.3) than those at distant of breeding sites.
CONCLUSIONS
Malaria remains a public health problem in the study localities. Thus, malaria prevention and control strategies targeting children, non-febrile cases and individuals living proximity to breeding sites are crucial to reduce malaria related morbidity and mortality.
Topics: Ethiopia; Cross-Sectional Studies; Prevalence; Humans; Risk Factors; Female; Male; Adolescent; Adult; Child, Preschool; Young Adult; Child; Middle Aged; Infant; Malaria, Vivax; Malaria, Falciparum; Family Characteristics; Plasmodium vivax; Plasmodium falciparum; Aged; Rural Population; Malaria
PubMed: 38735957
DOI: 10.1186/s12936-024-04965-4 -
PloS One 2024Quantitative diagnosis of glucose-6-phosphate dehydrogenase (G6PD) deficiency is essential for the safe administration of 8-aminoquinoline based radical cure for the...
Quantitative diagnosis of glucose-6-phosphate dehydrogenase (G6PD) deficiency is essential for the safe administration of 8-aminoquinoline based radical cure for the treatment of Plasmodium vivax infections. Here, we present the PreQuine Platform (IVDS, USA), a quantitative biosensor that uses a dual-analyte assay for the simultaneous measurement of Hemoglobin (Hgb) levels and G6PD enzyme activity within the same sample. The platform relies on a downloadable mobile application. The device requires 10μl of whole blood and works with a reflectance-based meter. Comparing the G6PD measurement normalized by Hgb of 12 samples from the PreQuine Platform with reference measurements methods (spectrophotometry, Pointe Scientific, USA and hemoglobin meter, HemoCue, Sweden) showed a positive and significant agreement with a slope of 1.0091 and an intercept of -0.0379 under laboratory conditions. Next steps will be to conduct field trials in Bangladesh, Cambodia, and the USA to assess diagnostic performance, user friendliness and acceptance.
Topics: Humans; Glucosephosphate Dehydrogenase; Glucosephosphate Dehydrogenase Deficiency; Hemoglobins; Biosensing Techniques; Malaria, Vivax; Aminoquinolines
PubMed: 38728310
DOI: 10.1371/journal.pone.0297918 -
Malaria Journal May 2024Plasmodium vivax relapses due to dormant liver hypnozoites can be prevented with primaquine. However, the dose must be adjusted in individuals with...
BACKGROUND
Plasmodium vivax relapses due to dormant liver hypnozoites can be prevented with primaquine. However, the dose must be adjusted in individuals with glucose-6-phosphate-dehydrogenase (G6PD) deficiency. In French Guiana, assessment of G6PD activity is typically delayed until day (D)14 to avoid the risk if misclassification. This study assessed the kinetics of G6PD activity throughout P. vivax infection to inform the timing of treatment.
METHODS
For this retrospective monocentric study, data on G6PD activity between D1 and D28 after treatment initiation with chloroquine or artemisinin-based combination therapy were collected for patients followed at Cayenne Hospital, French Guiana, between January 2018 and December 2020. Patients were divided into three groups based on the number of available G6PD activity assessments: (i) at least two measurements during the P. vivax malaria infection; (ii) two measurements: one during the current infection and one previously; (iii) only one measurement during the malaria infection.
RESULTS
In total, 210 patients were included (80, 20 and 110 in groups 1, 2 and 3, respectively). Data from group 1 showed that G6PD activity remained stable in each patient over time (D1, D3, D7, D14, D21, D28). None of the patients with normal G6PD activity during the initial phase (D1-D3) of the malaria episode (n = 44) was categorized as G6PD-deficient at D14. Patients with G6PD activity < 80% at D1 or D3 showed normal activity at D14. Sex and reticulocyte count were statistically associated with G6PD activity variation. In the whole sample (n = 210), no patient had severe G6PD deficiency (< 10%) and only three between 10 and 30%, giving a G6PD deficiency prevalence of 1.4%. Among the 100 patients from group 1 and 2, 30 patients (26.5%) were lost to follow-up before primaquine initiation.
CONCLUSIONS
In patients treated for P. vivax infection, G6PD activity did not vary over time. Therefore, G6PD activity on D1 instead of D14 could be used for primaquine dose-adjustment. This could allow earlier radical treatment with primaquine, that could have a public health impact by decreasing early recurrences and patients lost to follow-up before primaquine initiation. This hypothesis needs to be confirmed in larger prospective studies.
Topics: Adult; Aged; Female; Humans; Male; Middle Aged; Young Adult; Antimalarials; Artemisinins; Chloroquine; French Guiana; Glucosephosphate Dehydrogenase; Glucosephosphate Dehydrogenase Deficiency; Kinetics; Malaria, Vivax; Plasmodium vivax; Primaquine; Retrospective Studies; Aged, 80 and over
PubMed: 38725027
DOI: 10.1186/s12936-024-04973-4 -
ADMET & DMPK 2024and are responsible for most malaria cases in humans in the African Region and the Americas; these parasites have developed resistance to classic antimalarial drugs....
BACKGROUND AND PURPOSE
and are responsible for most malaria cases in humans in the African Region and the Americas; these parasites have developed resistance to classic antimalarial drugs. On the other hand, previous investigations of the alkyl-linked bis tetrahydro-(2H)-1,3,5-thiadiazine-2-thione (bis-THTT) derivatives compounds show satisfactory results against protozoan parasites such as , , and . Therefore, it is possible to see some effect of bis-THTT derivatives on other protozoan parasites, such as .
EXPERIMENTAL APPROACH
This study aimed to perform an biological evaluation of bis-THTT (JH1 to JH6) derivatives compounds as possible anti-malaria drugs in BALB/c mice infected with ANKA and 17XL strains. In this work, we evaluated the compounds as potential antimalarial drugs in BALB/c mice infected with strains.
KEY RESULTS
For each compound, we assess the percentages of parasitemia by smears from tail blood and the humoral response by indirect ELISA test using each compound as an antigen. We also evaluated the B lymphocyte response and the cytotoxicity of the bis-THTT derivatives compounds with MTT cell proliferation assays.
CONCLUSIONS
Our results show that the bis-THTT derivatives JH2 and JH4 presented effective parasitemia control in mice infected with ; JH5 and JH6 compounds have similar infection control results as chloroquine in mice infected strain. The evaluation of bis-THTT derivatives compounds in a model of BALB/c mice infected with and allowed us to conclude that some of them have an antimalarial effect; however, none of the tested compounds exceeded the efficiency of chloroquine.
PubMed: 38720925
DOI: 10.5599/admet.2105 -
MBio Jun 2024To combat the global burden of malaria, development of new drugs to replace or complement current therapies is urgently required. Here, we show that the compound is a...
To combat the global burden of malaria, development of new drugs to replace or complement current therapies is urgently required. Here, we show that the compound is a selective, nanomolar inhibitor of both and aminopeptidases M1 and M17, leading to inhibition of end-stage hemoglobin digestion in asexual parasites. can kill sexual-stage , is active against murine malaria, and does not show any shift in activity against a panel of parasites resistant to other antimalarials. -resistant exhibited a slow growth rate that was quickly outcompeted by wild-type parasites and were sensitized to the current clinical drug, artemisinin. Overall, these results confirm as a lead compound for further drug development and highlights the potential of dual inhibition of M1 and M17 as an effective multi-species drug-targeting strategy.IMPORTANCEEach year, malaria infects approximately 240 million people and causes over 600,000 deaths, mostly in children under 5 years of age. For the past decade, artemisinin-based combination therapies have been recommended by the World Health Organization as the standard malaria treatment worldwide. Their widespread use has led to the development of artemisinin resistance in the form of delayed parasite clearance, alongside the rise of partner drug resistance. There is an urgent need to develop and deploy new antimalarial agents with novel targets and mechanisms of action. Here, we report a new and potent antimalarial compound, known as , and show that it targets multiple stages of the malaria parasite lifecycle, is active in a preliminary mouse malaria model, and has a novel mechanism of action. Excitingly, resistance to appears to be self-limiting, suggesting that development of the compound may provide a new class of antimalarial.
Topics: Antimalarials; Plasmodium falciparum; Animals; Mice; Plasmodium vivax; Aminopeptidases; Drug Resistance; Humans; Malaria, Falciparum; Protozoan Proteins; Female
PubMed: 38717141
DOI: 10.1128/mbio.00966-24 -
Emerging Infectious Diseases Jul 2024Beginning in 2023, we observed increased Plasmodium vivax malaria cases at an institution in Los Angeles, California, USA. Most cases were among migrants from China who...
Beginning in 2023, we observed increased Plasmodium vivax malaria cases at an institution in Los Angeles, California, USA. Most cases were among migrants from China who traveled to the United States through South and Central America. US clinicians should be aware of possible P. vivax malaria among immigrants from China.
Topics: Humans; Malaria, Vivax; China; Emigrants and Immigrants; Plasmodium vivax; United States; Travel; Male; Adult; Female; Middle Aged; Young Adult
PubMed: 38710182
DOI: 10.3201/eid3007.240177 -
Vaccine Jun 2024Recent data indicate increasing disease burden and importance of Plasmodium vivax (Pv) malaria. A robust assay will be essential for blood-stage Pv vaccine development....
Recent data indicate increasing disease burden and importance of Plasmodium vivax (Pv) malaria. A robust assay will be essential for blood-stage Pv vaccine development. Results of the in vitro growth inhibition assay (GIA) with transgenic P. knowlesi (Pk) parasites expressing the Pv Duffy-binding protein region II (PvDBPII) correlate with in vivo protection in the first PvDBPII controlled human malaria infection (CHMI) trials, making the PkGIA an ideal selection tool once the precision of the assay is defined. To determine the precision in percentage of inhibition in GIA (%GIA) and in GIA (antibody concentration that gave 50 %GIA), ten GIAs with transgenic Pk parasites were conducted with four different anti-PvDBPII human monoclonal antibodies (mAbs) at concentrations of 0.016 to 2 mg/mL, and three GIAs with eighty anti-PvDBPII human polyclonal antibodies (pAbs) at 10 mg/mL. A significant assay-to-assay variation was observed, and the analysis revealed a standard deviation (SD) of 13.1 in the mAb and 5.94 in the pAb dataset for %GIA, with a LogGIA SD of 0.299 (for mAbs). Moreover, the ninety-five percent confidence interval (95 %CI) for %GIA or GIA in repeat assays was calculated in this investigation. The error range determined in this study will help researchers to compare PkGIA results from different assays and studies appropriately, thus supporting the development of future blood-stage malaria vaccine candidates, specifically second-generation PvDBPII-based formulations.
Topics: Malaria Vaccines; Plasmodium knowlesi; Protozoan Proteins; Plasmodium vivax; Antigens, Protozoan; Humans; Receptors, Cell Surface; Antibodies, Protozoan; Malaria, Vivax; Antibodies, Monoclonal; Vaccine Development; Animals
PubMed: 38704253
DOI: 10.1016/j.vaccine.2024.04.073