Vivax Infection Research Articles

Radical cure for Plasmodium vivax malaria after G6PD qualitative testing in four provinces in Cambodia, results from Phase I implementation

BackgroundCambodia aims to eliminate all forms of malaria by 2025. In 2020, 90% of all malaria cases were Plasmodium vivax. Thus, preventing P. vivax and relapse malaria is a top priority for elimination. 14-day primaquine, a World Health Organization-recommended radical cure treatment regimen, specifically targets dormant hypnozoites in the liver to prevent relapse. Cambodia introduced P. vivax radical cure with primaquine after glucose-6-phosphate dehydrogenase (G6PD) qualitative testing in 2019. This paper presents Cambodia’s radical cure Phase I implementation results and assesses the safety, effectiveness, and feasibility of the programme prior to nationwide scale up.MethodsPhase I implementation was carried out in 88 select health facilities (HFs) across four provinces. Males over 20kgs with confirmed P. vivax or mixed (P. vivax and Plasmodium falciparum) infections were enrolled. A descriptive analysis evaluated the following: successful referral to health facilities, G6PD testing results, and self-reported 14-day treatment adherence. P. vivax incidence was compared before and after radical cure rollout and a controlled interrupted time series analysis compared the estimated relapse rate between implementation and non-implementation provinces before and after radical cure.ResultsIn the 4 provinces from November 2019 to December 2020, 3,239 P. vivax/mixed infections were reported, 1,282 patients underwent G6PD deficiency testing, and 959 patients received radical cure, achieving 29.6% radical cure coverage among all P. vivax/mixed cases and 98.8% coverage among G6PD normal patients. Among those who initiated radical cure, 747 patients (78%) completed treatment. Six patients reported side effects. In implementation provinces, an average 31.8 relapse cases per month were estimated signaling a 90% (286 cases) reduction in relapse compared to what would be expected if radical cure was not implemented.ConclusionsPlasmodium vivax radical cure is a crucial tool for malaria elimination in Cambodia. The high coverage of radical cure initiation and adherence among G6PD normal patients demonstrated the high feasibility of providing radical cure at point of care in Cambodia. Incomplete referral from community to HFs and limited capacity of HF staff to conduct G6PD testing in high burden areas led to lower coverage of G6PD testing. Phase I implementation informed approaches to improve referral completion and patient adherence during the nationwide expansion of radical cure in 2021.

HRP2 and PLDH Performance Comparison as Rapid Diagnostic Tools for Symptomatic Malaria Patients at Rugazi HC IV in Rubirizi District

Background: Rapid and precise laboratory diagnosis is essential for effectively diagnosing and managing malaria patients. Malaria rapid diagnostic tests (mRDTs) play a critical role in malaria diagnosis in resource-constrained settings with limited access to labs and trained staff. The efficiency of two mRDTs (HRP2 and pLDH) was compared against microscopy, the gold standard for malaria diagnosis, in this study. Methods: In a cross-sectional study, 308 participants were tested for malaria parasites using two mRDTs and blood smear microscopy as the gold standard. STATA software version 17 was used for data analysis. Results: Out of the 308 participants, 82 tested positive for HRP2 mRDT (26.62% (95% CI: 21.97-31.86) positivity rate, 73.38% (95% CI: 68.14-78.83) negativity rate), and 99 tested positive for pLDH mRDT (32.14% (95% CI: 27.14-37.59) positivity rate, 67.86% (95% CI: 62.41-72.86) negativity rate). Using microscopy as the gold standard, the sensitivity, specificity, PPV, and NPV were determined. For HRP2 mRDT, sensitivity was 77.78% (95%CI: 73.13-82.42), specificity 97.61% (95%CI: 95.90 - 99.31), PPV 93.90% (95%CI: 91.23 – 96.56), and NPV 90.27% (95%CI: 86.96-93.58). For pLDH mRDT, the sensitivity was 94.95% (95% CI: 92.50-97.40), specificity was 97.61% (95% CI: 95.90-99.31), PPV was 94.95% (95% CI: 92.50 – 97.40), and NPV was 97.61% (95% CI: 95.90 - 99.31). The dominant malaria species was Plasmodium falciparum (74.7%), followed by Plasmodium vivax (12.1%) and Plasmodium ovale (1%). Mixed infections of plasmodium falciparum and plasmodium vivax (7.1%) and plasmodium falciparum and plasmodium ovale (5.1%) were also observed. Conclusion: There was no significant difference in the positivity rate, negativity rate, specificity or PPV in both mRDTs. However, a significant difference in the NPV and sensitivity of HRP2 and pLDH mRDTs was observed where HRP2’s sensitivity was below the WHO recommendation of ≥95% in this study population; thus, there is a need to improve the sensitivity of this mRDT kit. In our study, most malaria infections were caused by Plasmodium falciparum, followed by P. vivax and P. ovale. We therefore recommend the use of pLDH mRDTs over HRP2 mRDTs based on the results of our study

The Declined Trend of Malaria over a Ten-year Period in the Rural East Nusa Tenggara Province, Indonesia: A Medical Record Analysis

BACKGROUND: Malaria still remains a major public health problem globally including in Indonesia. At present, most of malaria cases are in the eastern part of the country. However, there is no information yet regarding the trends of malaria prevalence at rural health institution particularly at Mangili Public Health Centre. AIM: This study aims to explore the trend of malaria prevalence over a 10-year period. METHODS: A retrospective study was carried out in the center. The laboratory record books from January 2013 to December 2022 were carefully reviewed to identify malaria cases based on the sex, age, type of Plasmodium, year, and month when the patients diagnosed malaria microscopically. The trend analysis was applied to identify the trend of malaria over the period under review. RESULTS: Over the past 10 years, 19,938 blood films were requested for malaria diagnosis at the health center. From this number, 3.679 (18.5%, with 95% confidence interval (CI): 17.2–19.7) were microscopically confirmed malaria cases. From the total cases, prevalence of Plasmodium falciparum (Pf), vivax and mix infection was 85.5% with 95% CI: 84.3–86.8; 6.39% with 95% CI: 3.26–9.51; and 7.58% with 95% CI: 4.48–10.7, respectively. The number of malaria cases reached a peak in January, while it was the lowest in October. Overall trend on the prevalence of malaria decreased significantly; however, the prevalence of Pf increased considerably during COVID-19 pandemic. The prevalence of Pf, vivax, and mixed infection was higher in male, age group ≥ 15, and student than their counterpart. CONCLUSION: Malaria remains high in this area with Pf that is the dominant species followed by mixed infection. Scaling up malaria control and prevention activities is very crucial to significantly reduce the burden of malaria and to boost malaria elimination in this region.

Methemoglobin levels in malaria: a systematic review and meta-analysis of its association with Plasmodium falciparum and Plasmodium vivax infections and disease severity

Reports indicate that Plasmodium infections influence methemoglobin levels. However, findings have been inconclusive or have varied across different geographic and demographic contexts. This systematic review and meta-analysis aimed to consolidate existing data regarding the association between Plasmodium infections and alterations in methemoglobin levels related to the severity of the infection. A comprehensive literature search of several databases, including Ovid, ProQuest, Embase, Scopus, MEDLINE, and PubMed, was conducted to identify relevant studies that examined methemoglobin levels in patients with malaria. Qualitative synthesis and meta-analysis of the pooled standardized mean difference were conducted to synthesize the differences in methemoglobin levels between: (1) patients with malaria and those without malaria and (2) patients with severe malaria and those with uncomplicated malaria based on various themes including publication year, study design, study area, Plasmodium species, age group, symptomatic status, severity status, and method of malaria detection. Of the 1846 studies that were initially identified from the main databases and additional searches on Google Scholar, 10 studies met the eligibility criteria and were selected for this review. The systematic review distinctly highlighted an association between malaria and elevated methemoglobin levels, an observation consistent across diverse geographical regions and various Plasmodium species. Furthermore, the meta-analysis confirmed this by demonstrating increased methemoglobin levels in patients with malaria compared to those without malaria (P < 0.001, Hedges’ g 2.32, 95% CI 1.36–3.29, I2 97.27, 8 studies). Moreover, the meta-analysis found elevated methemoglobin levels in patients with severe malaria compared to those with uncomplicated malaria (P < 0.001, Hedges’ g 2.20, 95% CI 0.82–3.58, I2 96.20, 5 studies). This systematic review and meta-analysis revealed increased methemoglobin levels in patients with P. falciparum and P. vivax infections, with a notable association between elevated methemoglobin levels and severe malaria. Future research should focus on elucidating the specific mechanisms by which changes in methemoglobin levels are related to infections by P. falciparum and P. vivax, particularly in terms of severity, and how these alterations could potentially impact patient management and treatment outcomes.

Changing Clinical Epidemiology of Plasmodium vivax Malaria as Transmission Decreases: Population-Based Prospective Panel Survey in the Brazilian Amazon.

Malarial infections are often missed by microscopy, and most parasite carriers are asymptomatic in low-endemicity settings. Whether parasite detectability and its ability to elicit symptoms change as transmission declines remains unclear. We performed a prospective panel survey with repeated measurements on the same participants over 12 months to investigate whether Plasmodium vivax detectability by microscopy and risk of symptoms upon infection varied during a community-wide larviciding intervention in the Amazon basin of Brazil that markedly reduced vector density. We screened 1096 to 1400 residents in the intervention site for malaria by microscopy and quantitative TaqMan assays at baseline and twice during intervention. We found that more P vivax infections than expected from their parasite densities measured by TaqMan assays were missed by microscopy as transmission decreased. At lower transmission, study participants appeared to tolerate higher P vivax loads without developing symptoms. We hypothesize that changes in the ratio between circulating parasites and those that accumulate in the bone marrow and spleen, by avoiding peripheral blood microscopy detection, account for decreased parasite detectability and lower risk of symptoms under low transmission. P vivax infections are more likely to be subpatent and remain asymptomatic as malaria transmission decreases.

Profiling the antibody response of humans protected by immunization with Plasmodium vivax radiation-attenuated sporozoites

Malaria sterile immunity has been reproducibly induced by immunization with Plasmodium radiation-attenuated sporozoites (RAS). Analyses of sera from RAS-immunized individuals allowed the identification of P. falciparum antigens, such as the circumsporozoite protein (CSP), the basis for the RTS, S and R21Matrix-M vaccines. Similar advances in P. vivax (Pv) vaccination have been elusive. We previously reported 42% (5/12) of sterile protection in malaria-unexposed, Duffy-positive (Fy +) volunteers immunized with PvRAS followed by a controlled human malaria infection (CHMI). Using a custom protein microarray displaying 515 Pv antigens, we found a significantly higher reactivity to PvCSP and one hypothetical protein (PVX_089630) in volunteers protected against P. vivax infection. In mock-vaccinated Fy + volunteers, a strong antibody response to CHMI was also observed. Although the Fy- volunteers immunized with non-irradiated Pv-infected mosquitoes (live sporozoites) did not develop malaria after CHMI, they recognized a high number of antigens, indicating the temporary presence of asexual parasites in peripheral blood. Together, our findings contribute to the understanding of the antibody response to P. vivax infection and allow the identification of novel parasite antigens as vaccine candidates.Trial registration: ClinicalTrials.gov number: NCT 01082341.

Complement receptor 1 is the human erythrocyte receptor for Plasmodium vivax erythrocyte binding protein

The discovery that Africans were resistant to infection by Plasmodium vivax (P. vivax) led to the conclusion that P. vivax invasion relied on the P. vivax Duffy Binding Protein (PvDBP) interacting with the Duffy Antigen Receptor for Chemokines (DARC) expressed on erythrocytes. However, the recent reporting of P. vivax infections in DARC-negative Africans suggests that the parasite might use an alternate invasion pathway to infect DARC-negative reticulocytes. To identify the parasite ligands and erythrocyte receptors that enable P. vivax invasion of both DARC-positive and -negative erythrocytes, we expressed region II containing the Duffy Binding-Like (DBL) domain of P. vivax erythrocyte binding protein (PvEBP-RII) and verified that the DBL domain binds to both DARC-positive and -negative erythrocytes. Furthermore, an AVidity-based EXtracelluar Interaction Screening (AVEXIS) was used to identify the receptor for PvEBP among over 750 human cell surface receptor proteins, and this approach identified only Complement Receptor 1 (CR1, CD35, or C3b/C4b receptor) as a PvEBP receptor. CR1 is a well-known receptor for P. falciparum Reticulocyte binding protein Homology 4 (PfRh4) and is present on the surfaces of both reticulocytes and normocytes, but its expression decreases as erythrocytes age. Indeed, PvEBP-RII bound to a subpopulation of both reticulocytes and normocytes, and this binding was blocked by the addition of soluble CR1 recombinant protein, indicating that CR1 is the receptor of PvEBP. In addition, we found that the Long Homology Repeat A (LHR-A) subdomain of CR1 is the only subdomain responsible for mediating the interaction with PvEBP-RII.

Analysing the six-year malaria trends at Metehara Health Centre in Central Ethiopia: the impact of resurgence on the 2030 elimination goals

BackgroundDespite Ethiopia’s concerted efforts to eliminate malaria by 2030, the disease continues to pose a significant public health and socioeconomic challenge in the country. The year 2021 witnessed 2.78 million malaria cases and 8041 associated deaths, emphasizing the persistent threat. Monitoring the prevalence trend of malaria is crucial for devising effective control and elimination strategies. This study aims to assess the trend of malaria prevalence at the Metehara Health Centre in the East Shoa Zone, Ethiopia.MethodsA retrospective study, spanning from February to September 2023, utilized malaria registration laboratory logbooks at Metehara Health Centre to evaluate the prevalence of malaria from 2017/18 to 2022/23. Malaria and related data were collected using a pre-designed data collection sheet. Descriptive statistics were employed for data summarization, presented through graphs and tables.ResultsOut of 59,250 examined blood films, 17.4% confirmed the presence of Plasmodium infections. Among the confirmed cases, 74.3%, 23.8%, and 1.84% were attributed to Plasmodium falciparum, Plasmodium vivax, and mixed infections, respectively. The trend of malaria exhibited a steady decline from 2017/18 to 2021/22, reaching 9.8% prevalence. However, an abrupt increase to 26.5% was observed in 2022/23. Males accounted for a higher proportion (66%) of cases compared to females (34%). The age group 15–24 years experienced the highest malaria incidence at 42%. Notably, malaria cases peaked during autumn (September to November) at 43% and reached the lowest percentage during spring (March to May) at 13%.ConclusionMalaria persists as a significant health challenge in and around Metehara, central Ethiopia, predominantly driven by Plasmodium falciparum. The five-year declining trend was interrupted by a notable upsurge in 2022/23, indicating a resurgence of malaria in the study area. It is imperative to adopt a reverse strategy to sustain the progress achieved by the national malaria control plan.

Artemisinin-naphthoquine plus lower-dose primaquine to treat and prevent recurrence of Plasmodium vivax malaria: an open-label randomized and non-inferiority trial.

Plasmodium vivax malaria, with the widest geographic distribution, can cause severe disease and death. Primaquine is the main licensed antimalarial drug that can kill hypnozoites. The dose-dependent acute haemolysis in individuals with glucose-6-phospate dehydrogenase (G6PD) deficiency is the main safety concern when using primaquine. The recommended treatment regimen for P. vivax malaria is chloroquine plus primaquine for 14days (CQPQ14) in Myanmar. The study aimed to evaluate the therapeutic efficacy, safety and adherence for the regimen of artemisinin-naphthoquine plus primaquine for 3days (ANPQ3) in patients with P. vivax infections compared to those with CQPQ14. The patients in the ANPQ3 group were given fixed-dose artemisinin-naphthoquine (a total 24.5mg/kg bodyweight) plus a lower total primaquine dose (0.9mg/kg bodyweight) for 3days. The patients in the CQPQ14 group were given a total chloroquine dose of 30mg/kg body weight for 3days plus a total primaquine dose of 4.2mg/kg bodyweight for 14days. All patients were followed up for 365days. A total of 288 patients completed follow-up, 172 in the ANPQ3 group and 116 in the CQPQ14 group. The first recurrence patients were detected by day 58 in both groups. By day 182, 16 recurrences had been recorded: 12 (7.0%) patients in the ANPQ3 group and 4 (3.4%) in the CQPQ14 group. The difference in recurrence-free patients was 3.5 (-8.6 to 1.5) percentage points between ANPQ3 and CQPQ14 group (P = 0.2946). By day 365, the percentage of recurrence-free patients was not significant between the two groups (P = 0.2257). Mean fever and parasite clearance time of ANPQ3 group were shorter than those in CQPQ14 group (P ≤ 0.001). No severe adverse effect was observed in ANPQ3 group, but five (3.9%) patients had acute haemolysis in CQPQ14 group (P = 0.013). Medication percentage of ANPQ3 group was significantly higher than that of CQPQ14 group (P < 0.0001). Both ANPQ3 and CQPQ14 promised clinical cure efficacy, and the radical cure efficacy was similar between the ANPQ3 and CQPQ14 group. ANPQ3 clears fever and parasites faster than CQPQ14. ANPQ3 is safer and shows better patient adherence to the regimen for treatment of P. vivax malaria along the China-Myanmar border. ChiCTR-INR-17012523. Registered 31 August 2017, https://www.chictr.org.cn/showproj.html?proj=21352.

In-vitro susceptibility and ex-vivo evaluation of macrocyclic lactone endectocides sub-lethal concentrations against Plasmodium vivax oocyst development in Anopheles arabiensis

BackgroundAsymptomatic malaria transmission has become a public health concern across malaria-endemic Africa including Ethiopia. Specifically, Plasmodium vivax is more efficient at transmitting earlier in the infection and at lower densities than Plasmodium falciparum. Consequently, a greater proportion of individuals infected with P. vivax can transmit without detectable gametocytaemia. Mass treatment of livestock with macrocyclic lactones (MLs), e.g., ivermectin and doramectin, was suggested as a complementary malaria vector tool because of their insecticidal effects. However, the effects of MLs on P. vivax in Anopheles arabiensis has not yet been fully explored. Hence, comparative in-vitro susceptibility and ex-vivo studies were conducted to evaluate the effects of ivermectin, doramectin and moxidectin sub-lethal concentrations on P. vivax oocyst development in An. arabiensis.MethodsThe 7-day sub-lethal concentrations of 25% (LC25) and 5% (LC5) were determined from in-vitro susceptibility tests on female An. arabiensis in Hemotek® membrane feeding assay. Next, an ex-vivo study was conducted using P. vivax gametocytes infected patient’s blood spiked with the LC25 and LC5 of the MLs. At 7-days post-feeding, each mosquito was dissected under a dissection stereo microscope, stained with 0.5% (w/v) mercurochrome solution, and examined for the presence of P. vivax oocysts. Statistical analysis was based on a generalized mixed model with binomially distributed error terms.ResultsA 7-day lethal concentration of 25% (LC25, in ng/mL) of 7.1 (95% CI: [6.3;8.0]), 20.0 (95%CI:[17.8;22.5]) and 794.3 (95%CI:[716.4;1516.3]) were obtained for ivermectin, doramectin and moxidectin, respectively. Similarly, a lethal concentration of 5% (LC5, in ng/mL) of 0.6 (95% CI: [0.5;0.7]), 1.8 (95% CI:[1.6;2.0]) and 53.7 (95% CI:[ 48.4;102.5]) were obtained respectively for ivermectin, doramectin and moxidectin. The oocyst prevalence in treatment and control groups did not differ significantly (p > 0.05) from each other. Therefore, no direct effect of ML endectocides on P. vivax infection in An. arabiensis mosquitoes was observed at the sub-lethal concentration (LC25 and LC5).ConclusionsThe effects of ivermectin and doramectin on malaria parasite is more likely via indirect effects, particularly by reducing the vectors lifespan and causing mortality before completing the parasite’s sporogony cycle or reducing their vector capacity as it affects the locomotor activity of the mosquito.

Accuracy of Haematology Analyzer in the Diagnosis of Malaria in Comparison with Gold Standard Microscopy

Objective: To assess the accuracy of Haematology analyzer in the diagnosis of malaria in comparison with gold standard microscopy.&#x0D; Methodology: A cross-sectional study was conducted at the Pakistan Institute of Medical Sciences and the Pakistan Atomic Energy Commission in Islamabad, Pakistan. The study was conducted for around six months, from May 2023 to October 2023. The Mindray BC-6200 haematology analyzer was utilised to evaluate a total of 191 samples, comprising 127 samples from that were infected with malaria and 64 samples from healthy controls. When the presence of malaria parasites, identified as Plasmodium vivax and Plasmodium falciparum, was detected in dyed thick blood film, a microscopy examination was carried out as a reference. Analyse-it v4.92.3 was used to create the receiver operating characteristic (ROC) curve analysis. The agreement between BC-6200 and light microscopy was assessed using the Kappa value.&#x0D; Results: The InR by BC-6200's sensitivity and specificity for P. falciparum and P. vivax infections. The sensitivity of the InR by BC-600 for P. falciparum and P. vivax was 27.9% and 85.5%, respectively. The specificity of the InR by BC-6200 for P. vivax and P. falciparum was 82.7% and 86.5%, respectively. The infection densities in microscopy varied statistically significantly between the various InR groups (χ2 = 14.50, P &lt; 0.005).An analysis was conducted on the correlation between the cell blood count and the count of InR in both the P. vivax and P. falciparum-infected patient groups. The results showed a clear correlation between InR (P. vivax group R2 = 0.87) and ΔWBC (WBCDIFF–WBCBASO). In the Mindray BC-6200 haematology analyzer, WBCBASO represents the number of WBC counting in the BASO channel with severe membrane degradation, while WBCDIFF represents the number of WBC counting in the DIFF channel with mild lyse. The volume distribution widths of RBC, HGB, and red blood cells did not differ substantially. The reticulocyte characteristics of the P. vivax/P. falciparum patient group and control group differed significantly (P&lt;0.02), although RBC, HGB, and red blood cell volume distribution width (RDW) did not differ significantly (P &gt; 0.05). There was a significant difference (P&lt;0.02) in the PLT count between the P. vivax/P. falciparum patient groups and the control group.&#x0D; Conclusion: The results imply that malaria might be screened for in a clinical setting using the BC-6200 haematology analyzer's "InR" flag and "InR#/InR‰" parameters.

An imported malaria case with repeated episodes of neurological syndromes resulting from different Plasmodium species

BackgroundImported cerebral malaria (CM) cases in non-endemic areas are often misdiagnosed, which delays treatment. Post-malaria neurological syndrome (PMNS) after recovery from severe malaria can also complicate diagnosis.CaseWe report an imported malaria case from West Africa with two sequential episodes with neurological syndromes within about a month. The first episode was diagnosed as CM with microscopy-positive Plasmodium falciparum infection. The second episode, occurring a month after the recovery from the first CM episode, was consistent with PMNS, since malaria parasites were not detected by microscopy in peripheral blood smears. However, this diagnosis was complicated by the detection of Plasmodium vivax in peripheral blood by PCR, suggesting a potential cause of the second episode by P. vivax.ConclusionThis study suggests that PMNS often occurs after severe falciparum malaria. Concurrent P. vivax infection with pathogenic biomass being predominantly extravascular further complicates accurate diagnosis.

Splenic Infarct: A Rare Complication of Plasmodium Vivax

Malaria is associated with various complications, with splenic infarction being a rare occurrence. The exact number of splenic infarction cases remains unclear due to misdiagnosis or underreporting. While Plasmodium falciparum is notorious for severe complications, Plasmodium Vivax, generally considered benign, can lead to serious issues such as severe anemia, respiratory collapse, splenic complications, and shock [1]. This report describes a case of splenic infarction as a complication of P. Vivax infection. In malaria-endemic areas, clinicians should pay special attention to patients with splenomegaly and left upper quadrant pain, as these symptoms may indicate splenic infarction.

Detection of anti-Trypanosoma spp. antibodies in cattle from southern Brazil.

Bovine trypanosomosis, caused by Trypanosoma vivax, is a disease that originated in Africa and currently affects cattle in several South American countries, including almost all Brazilian states. Despite the reports on T. vivax infection in southern Brazil, data on its circulation status is currently unavailable. In this study, we aimed to detect anti-Trypanosoma spp. IgG antibodies in cattle from Rio Grande do Sul and suggest areas with T. vivax transmission risk. A total of 691 serum samples from cattle in the intermediate regions of Rio Grande do Sul were analyzed using indirect immunofluorescence assay (IFA). The overall seroprevalence of anti-Trypanosoma antibodies in cattle was 24.6% (170/691). The detection rate ranged from 0-37.3%, with a high prevalence in the intermediate regions of Ijuí (37.3%), Uruguaiana (30.7%), and Passo Fundo (28.9%). Thus, these regions were suggested as possible bovine trypanosomosis risk areas due to the high seroprevalence. This is the first serological study to determine Trypanosoma spp. infection status in cattle from Rio Grande do Sul, providing data on the epidemiology of trypanosomosis in the state.

Prevalence and correlates of malaria and undernutrition among acutely febrile children visiting temporary malaria screening sites in war-torn areas of Northeast Ethiopia.

Malaria and undernutrition pose challenges for children in conflict-affected areas. Understanding the prevalence and risk factors for these issues in war-torn communities is important to effectively design aid efforts and select interventions. This study aimed to determine the prevalence and correlates of malaria and undernutrition among febrile children in northeast Ethiopia to help address these problems. A cross-sectional study was conducted from November 2022 to January 2023. Four hundred twenty-two children were enrolled using a systematic random sampling technique. Data on associated factor variables were collected via questionnaire. Capillary blood samples were collected from each child to prepare thick and thin blood films, which were stained with Giemsa and examined microscopically. Height and weight measurements were also taken using a meter and a standard calibrated balance. The data were analyzed in SPSS 26.0 using bivariable and multivariable logistic regression to determine associations between correlates, malaria infection, and undernutrition. Statistical significance was set at p < 0.05. The overall malaria prevalence among screened children at temporary sites in the conflict-affected areas of Northeast Ethiopia was 65.9% (278/422). Plasmodium falciparum, P. vivax, and mixed infections accounted for 74.1%, 19.8%, and 6.1% of the cases, respectively. The presence of stagnant water (P<0.01), improper utilization of ITN, inadequate number of ITNs per family size (P<0.01), and absence of environmental management (P<0.01) were independent predictors of malaria. On the other hand, the overall undernutrition prevalence was 54.7% (231/422), including 26.5% underweight, 16.8% stunted, and 11.4% wasted. Dietary diversity score (P<0.01), meal frequency (P<0.01), and confirmed malaria infection (P<0.01) were significantly associated with underlnutrition. Both malaria and undernutrition burdens were high among the children in this study. The findings suggest combined prevention measures for malaria and undernutrition should be strengthened in this region.

High seroprevalence of IgM antibodies against chikungunya among patients with acute febrile illness seeking healthcare in a malaria-endemic area in the Afar Region, Northeast Ethiopia.

Chikungunya is a disease caused by Aedes mosquito-borne chikungunya virus infection. This disease is becoming one of the emerging/re-emerging viral diseases in tropical and subtropical countries but is neglected by public health systems. This study assessed the seroprevalence of chikungunya virus infection among patients with acute febrile illness seeking healthcare in a malaria-endemic area in the Afar Region, Northeast Ethiopia. An institution-based cross-sectional study was employed from September 2022 to March 2023 to assess the seroprevalence of chikungunya virus infection among malaria-suspected febrile patients attending health institutes in the Afar Region. Sociodemographic, clinical features, and venous blood were collected from each study participant. Blood films were prepared and examined for plasmodium infection using microscopy. Sera were separated and screened for anti-chikungunya virus IgM and IgG antibodies using an enzyme-linked immunosorbent assay. Data were entered into Epi Data 3.1 and analyzed using Stata/SE 14.2. In this study, 368 malaria-suspected febrile patients (55.4% female, aged 5-80 years old, mean ± SD = 27.28 ± 14.0) participated. The prevalence of anti-chikungunya virus IgM antibodies, indicating acute infection, was 47.8%, while the prevalence of IgG antibodies, indicating previous exposure, was 6.3%. Nonmarried participants were found to be more likely to have acute chikungunya virus infection (AOR = 2.34, 95% CI: 1.141-4.964), and back pain was associated with higher likelihood of acute infection (AOR = 1.785; 95% CI: 1.078-2.954). About 10.6% of the participants tested positive for Plasmodium parasite infection, with P. falciparum (84.6%) being the most common, followed by P. vivax (10.3%) and mixed (5.1%) infections. The study revealed a high seroprevalence of acute chikungunya virus infection among febrile patients in the Afar Region, highlighting the importance of regular screening for arbovirus infection in febrile patients to control and mitigate chikungunya spread.

A snapshot of a representative Brazilian state of illegal mining in indigenous areas during the era of malaria elimination.

Malaria is a public health problem and the cases diagnosed in the capital of Roraima, Brazil, show potential to characterize the burden of the disease in the state. This study aimed to describe the epidemiological, clinical, and laboratory aspects of malaria cases diagnosed in Boa Vista. For this purpose, a descriptive, cross-sectional study was conducted in two health units in the city, with individuals diagnosed and who agreed to respond the questionnaire. Of the total of 206 participants, characterized as men, mixed-race, and young, 96% (198) reported participating in illegal mining activity. Among the group of miners, 66% (131) came from other states of Brazil or other countries. The mines were mainly located in the Yanomami territory in Roraima. Plasmodium vivax infection occurred in 74% (153) of participants. In the miner's group, hospitalizations for severe malaria, previous malaria attacks, and delays in treatment after the onset of symptoms were reported. Although 73% (145) of miners reported knowing how malaria was transmitted, only 54% (107) used mosquito nets or repellents. The use of Artecom and chloroquine by miners is not for the complete treatment but only to relieve symptoms for returning to gold mines, highlighting the importance of molecular surveillance to antimalarial resistance. Indigenous peoples are considered vulnerable to malaria and miners promotes the increase of malaria in Roraima Indigenous Lands. Therefore, access to diagnosis and treatment in Indigenous areas invaded by miners is imperative to confront this disease that ravages Indigenous communities and threatens public health on a large scale to achieve the goal of eliminating malaria in the state.

Comparative Analysis of PCR, Real-time PCR and LAMP Techniques in the Diagnosis of Trypanosoma vivax Infection in Naturally Infected Buffaloes and Cattle in the Brazilian Amazon

Comparative Analysis of PCR, Real-time PCR and LAMP Techniques in the Diagnosis of Trypanosoma vivax Infection in Naturally Infected Buffaloes and Cattle in the Brazilian Amazon

Fine-Scale Spatial Prediction on the Risk of Plasmodium vivax Infection in the Republic of Korea.

Malaria elimination strategies in the Republic of Korea (ROK) have decreased malaria incidence but face challenges due to delayed case detection and response. To improve this, machine learning models for predicting malaria, focusing on high-risk areas, have been developed. The study targeted the northern region of ROK, near the demilitarized zone, using a 1-km grid to identify areas for prediction. Grid cells without residential buildings were excluded, leaving 8,425 cells. The prediction was based on whether at least one malaria case was reported in each grid cell per month, using spatial data of patient locations. Four algorithms were used: gradient boosted (GBM), generalized linear (GLM), extreme gradient boosted (XGB), and ensemble models, incorporating environmental, sociodemographic, and meteorological data as predictors. The models were trained with data from May to October (2019-2021) and tested with data from May to October 2022. Model performance was evaluated using the area under the receiver operating characteristic curve (AUROC). The AUROC of the prediction models performed excellently (GBM = 0.9243, GLM = 0.9060, XGB = 0.9180, and ensemble model = 0.9301). Previous malaria risk, population size, and meteorological factors influenced the model most in GBM and XGB. Machine-learning models with properly preprocessed malaria case data can provide reliable predictions. Additional predictors, such as mosquito density, should be included in future studies to improve the performance of models.

Thrombocytopenia and its Severity in Plasmodium Vivax Positive Patients

Background: Plasmodium vivax, one of the four species of human malaria parasites, is responsible for a considerable portion of malaria cases. While P. vivax is often considered less severe than Plasmodium falciparum, it is not without its complications. Thrombocytopenia is a common hematological complication associated with malaria infections, including those caused by P. vivax. Objective: To evaluate the severity of thrombocytopenia and relationship between thrombocytopenia and demographic factors, such as age and gender, in Plasmodium vivax positive patients. Study Design: Cross sectional study. Settings: Medicine OPD of Liaquat University of Medical and Health Sciences / Jamshoro and Muhammad Medical College, Mirpur Khas Pakistan. Duration: Six months from May 2022 to October 2022. Methods: Individuals aged over 12 years of either gender with a confirmed diagnosis of Plasmodium vivax were included. A single blood sample was collected from each participant for platelet count analysis, and demographic details and platelet counts were recorded using standardized data collection forms. Thrombocytopenia was defined as a platelet count below a predetermined threshold (e.g., &lt;150,000 platelets/μL). All the information was collected via study proforma and SPSS version 26 was used for the analysis. Results: The participants had a mean age of 29.07 years. 122 individuals (61.3%) were male, and 77 individuals (38.7%) were female. Thrombocytopenia was highly prevalent in patients with a positive diagnosis of Plasmodium vivax, with a frequency of 83.4%. Among the affected individuals, 18.6% had mild thrombocytopenia, 38.2% had moderate thrombocytopenia, and 25.6% were observed with severe thrombocytopenia. According to the thrombocytopenia and its severity based on age and gender the p-values of 0.069 and 0.656 indicates no significant association of age and gender with thrombocytopenia severity. Conclusion: Study revealed a significant frequency of moderate to severe thrombocytopenia in individuals diagnosed with Plasmodium vivax infection and tends to be of moderate to severe intensity, without significant correlation of age and gender.