Correlation between antifungal clinical practices and a new clinical decision support system ANTIFON-CLIC® for the treatment of invasive candidiasis: a retrospective multicentre study.

BACKGROUND: Invasive candidiasis is still recognized as a major cause of morbidity and mortality. To support clinicians in the optimal use of antifungals for the treatment of invasive candidiasis, a computerized decision support system (CDSS) was developed based on institutional guidelines. OBJECTIVES: To evaluate the correlation of this newly developed CDSS with clinical practices, we set-up a retrospective multicentre cohort study with the aim of providing the concordance rate between the CDSS recommendation and the medical prescription (NCT05656157). PATIENTS AND METHODS: Adult patients who received caspofungin or fluconazole for the treatment of an invasive candidiasis were included. The analysis of factors associated with concordance was performed using mixed logistic regression models with department as a random effect. RESULTS: From March to November 2022, 190 patients were included from three centres and eight departments: 70 patients from centre A, 84 from centre B and 36 from centre C. Overall, 100 patients received caspofungin and 90 received fluconazole, mostly (59%; 112/190) for empirical/pre-emptive treatment. The overall percentage of concordance between the CDSS and medical prescriptions was 91% (173/190) (confidence interval 95%: 82%-96%). No significant difference in concordance was observed considering the centres (P > 0.99), the department of inclusion (P = 0.968), the antifungal treatment (P = 0.656) or the indication of treatment (P = 0.997). In most cases of discordance (n = 13/17, 76%), the CDSS recommended fluconazole whereas caspofungin was prescribed. The clinical usability evaluated by five clinicians was satisfactory. CONCLUSIONS: Our results demonstrated the high correlation between current antifungal clinical practice and this user-friendly and institutional guidelines-based CDSS.

Outcome of patients with cystic fibrosis colonized by Scedosporium and Lomentospora species: A longitudinal cohort study.

Scedosporium and Lomentospora species rank second among the filamentous fungi colonizing the airways of cystic fibrosis (CF) patients. These fungi could be responsible for allergic bronchopulmonary mycosis (ABPM) and bronchitis before lung transplantation and invasive infections after. However, their role in CF lung disease is debated. This study aimed to identify clinical or environmental factors associated with an airway colonization by Scedosporium/Lomentospora species in patients with CF over a period of 7 years. A longitudinal cohort study was conducted from 2008 to 2014 in the CF reference centre in Lyon, France, to compare the characteristics of patients with Scedosporium/Lomentospora colonized and non-colonized patients. During the study period, 283 patients completed the clinical and microbiological follow-up. The analysis revealed that a higher number and duration of hospitalizations, an increased number of courses of parenteral antibiotic therapy, a history of ABPA, and treatment by itraconazole were significantly associated with an airway colonization by Scedosporium/Lomentospora species. The rate of decline of forced expiratory volume in the first second was not statistically different between colonized and non-colonized patients. This study provides evidence that patients colonized by Scedosporium/Lomentospora species require more medical care than non-colonized patients. Additional care could be in part explained by the management of Scedosporium/Lomentospora-related diseases such as ABPM or bronchitis. However, we did not demonstrate a faster rate of decline of respiratory function or body mass index in colonized patients, suggesting, as previously reported, that colonization of the airways by these fungi does not play a significant role in the progression of CF disease.

This prospective study did not demonstrate a faster rate of decline of respiratory function or body mass index in cystic fibrosis (CF) patients colonized by Scedosporium/Lomentospora species compared to non-colonized patients, suggesting that these fungi do not play a significant role in the progression of CF disease.

Pre-referral intranasal artesunate powder for cerebral malaria: a proof-of-concept study.

BACKGROUND: Malaria still kills young children in rural endemic areas because early treatment is not available. Thus, the World Health Organization recommends the administration of artesunate suppositories as pre-referral treatment before transportation to the hospital in case of severe symptoms with an unavailable parenteral and oral treatment. However, negative cultural perception of the rectal route, and limited access to artesunate suppositories, could limit the use of artesunate suppositories. There is, therefore, a need for an alternative route for malaria pre-referral treatment. The aim of this study was to assess the potential of intranasal route for malaria pre-referral treatment. METHODS: The permeability of artesunate through human nasal mucosa was tested in vitro. The Transepithelial Electrical Resistance (TEER) of the nasal mucosa was followed during the permeation tests. Beside, regional deposition of artesunate powder was assessed with an unidose drug delivery device in each nostril of a nasal cast. Artesunate quantification was performed using Liquid Chromatography coupled to tandem Mass Spectrometry. RESULTS: The experimental model of human nasal mucosa was successfully implemented. Using this model, artesunate powder showed a much better passage rate through human nasal mucosa than solution (26.8 ± 6.6% versus 2.1 ± 0.3%). More than half (62.3%) of the artesunate dose sprayed in the nostrils of the nasal cast was recovered in the olfactory areas (44.7 ± 8.6%) and turbinates (17.6 ± 3.3%) allowing nose-to-brain and systemic drug diffusion, respectively. CONCLUSION: Artesunate powder showed a good permeation efficiency on human nasal mucosa. Moreover it can be efficiently sprayed in the nostrils using unidose device to reach the olfactory area leading to a fast nose-to-brain delivery as well as a systemic effect. Taken together, those results are part of the proof-of-concept for the use of intranasal artesunate as a malaria pre-referral treatment.

Impact of COVID-19 pandemic on antifungal consumption: a multicenter retrospective analysis.

BACKGROUND: In the context of COVID-19 pandemic, antifungal overuse may have occurred in our hospitals as it has been previously reported for antibacterials. METHODS: To investigate the impact of COVID-19 on antifungal consumption, a multicenter retrospective study including four medical sites and 14 intensive care units (ICU) was performed. Antifungal consumption and incidences of invasive fungal diseases before and during COVID-19 pandemic, for non-COVID-19 patients and COVID-19 patients, were described. RESULTS: An increase in voriconazole consumption was observed in 2020 compared with 2019 for both the whole hospital and the ICU (+ 40.3% and + 63.7%, respectively), whereas the incidence of invasive aspergillosis significantly increased in slightly lower proportions in the ICU (+ 46%). Caspofungin consumption also increased in 2020 compared to 2019 for both the whole hospital and the ICU (+ 34.9% and + 17.0%, respectively) with an increased incidence of invasive candidiasis in the whole hospital and the ICU but in lower proportions (+ 20.0% and + 10.9%, respectively). CONCLUSIONS: We observed an increased consumption of antifungals including voriconazole and caspofungin in our hospital during the COVID-19 pandemic and explained in part by an increased incidence of invasive fungal diseases in COVID-19 patients. These results are of utmost importance as it raises concern about the urgent need for appropriate antifungal stewardship activities to control antifungal consumption.

Mycetoma and Chromoblastomycosis: Perspective for Diagnosis Improvement Using Biomarkers.

BACKGROUND: Mycetoma and chromoblastomycosis are both chronic subcutaneous infectious diseases that pose an obstacle to socioeconomic development. Besides the therapeutic issue, the diagnosis of most neglected tropical diseases (NTD) is challenging. Confirmation using direct microscopy and culture, recognized as WHO essential diagnostic tests, are limited to specialized facilities. In this context, there is a need for simple user-friendly diagnostic tests to be used in endemic villages. METHODS: This review discuss the available biomarkers that could help to improve the diagnostic capacity for mycetoma and chromoblastomycosis in a theoretical and practical perspective. RESULTS: A lack of research in this area has to be deplored, mainly for mycetoma. Biomarkers based on the immune response (pattern of leucocytes, antibody detection), the dermal involvement (extracellular matrix monitoring, protein expression), and the presence of the infectious agent (protein detection) are potential candidates for the detection or follow-up of infection. CONCLUSION: Confirmatory diagnosis based on specific diagnostic biomarkers will be the basis for the optimal treatment of mycetoma and chromoblastomycosis. It will be part of the global management of NTDs under the umbrella of stewardship activities.

Comparison of fks gene mutations and minimum inhibitory concentrations for the detection of Candida glabrata resistance to micafungin: A systematic review and meta-analysis.

Candida resistance to antifungals impaired invasive candidiasis outcome. In a context of echinocandin resistance development, we aimed to evaluate the association between phenotypic resistance to micafungin and fks mutations of Candida glabrata. For this systematic review and meta-analysis, we searched MEDLINE, Scopus and Web of Science for reports published up to December 2017. Studies of C glabrata candidiasis with minimum inhibitory concentrations (MIC) determination of micafungin and fks genotyping were included. Reviews, studies not using reference methods, non-glabrata Candida, experimental isolates and undetailed mutations were excluded. Two authors independently assessed the eligibility of articles and extracted data. The main outcome was the diagnostic accuracy of fks mutations compared to micafungin MIC for C glabrata, measured as fixed-effect odd ratio. Heterogeneity was calculated with the I2 statistic. This study is registered with PROSPERO (CRD42018082023). Twenty-four studies were included in the meta-analysis. Pooled analysis found that S663P (OR 7.25, 95% CI 3.50-15.00; P < 0.00001), S629P (OR 3.70, 1.64-8.33; P = 0.002) and F659del (OR 5.66, 1.22-26.18; P = 0.03) were associated with increased risk of having a resistant isolate according to authors' interpretation of MICs. In sensitivity analysis based on new CLSI clinical breakpoints, the ORs for S663P and S629P remained significant. Genotyping of isolates of C glabrata for S663P and S629P mutations is an effective alternative to micafungin susceptibility tests. Relevant molecular markers of drug resistance will significantly improve the management of C glabrata infections.

Cryptic Plasmodium ovale concurrent with mixed Plasmodium falciparum and Plasmodium malariae infection in two children from Central African Republic.

BACKGROUND: Since several malaria parasite species are usually present in a particular area, co-infections with more than one species of Plasmodium are more likely to occur in humans infected in these areas. In many mixed infections, parasite densities of the cryptic species may be low and often not recognized in clinical practice. CASE PRESENTATION: Two children (3 and 6 years old) adopted recently from Central African Republic were admitted to hospital because of intermittent fever. Thin blood smears stained with Giemsa showed Plasmodium falciparum and Plasmodium malariae co-infection for both children at admission. They were both treated with atovaquone-proguanil combination for 3 days. At day 7, both thin blood smears examination remained negative but at day 28, thin blood smear was positive for P. malariae trophozoites and for Plasmodium ovale for the girl and her brother, respectively. Samples collected at day 1 and day 28 were submitted to real-time PCR showing the presence of the three parasite species (P. falciparum, P malariae and P. ovale) in admission blood samples from the two children and only P. ovale at day 28. CONCLUSIONS: Twenty-eight days follow-up after treatment led to detection of a third parasite species in the blood of these two patients suggesting covert co-infection and a delayed appearance of one cryptic species following treatment. Concurrently infecting malaria species could be mutually suppressive, with P. falciparum tending to dominate other species. These observations provide more evidence that recommendations for treatment of imported malaria should take into account the risk of concurrent or cryptic infection with Plasmodium species. Clinicians and biologists should be aware of the underestimated frequency of mixed infections with cryptic species and of the importance of patient follow-up at day 28. Future guidelines should shed more light on the treatment of mixed infection and on the interest of using artemisinin-based combinations for falciparum and non-falciparum species.

Genetic diversity of Plasmodium vivax metacaspase 1 and Plasmodium vivax multi-drug resistance 1 genes of field isolates from Mauritania, Sudan and Oman.

BACKGROUND: Plasmodium vivax is the second most important human malaria parasite, widely spread across the world. This parasite is associated with important issues in the process toward malaria elimination, including potential for relapse and increased resistance to chloroquine. Plasmodium vivax multi-drug resistant (pvmdr1) is suspected to be a marker of resistance although definitive evidence is lacking. Progress has been made in knowledge of biological factors affecting parasite growth, including mechanisms of regulated cell death and the suspected role of metacaspase. Plasmodium vivax metacaspase1 (PvMCA1-cd) has been described with a catalytic domain composed of histidine (H372) and cysteine (C428) residues. The aim of this study was to test for a link between the conserved histidine and cysteine residues in PvMCA1-cd, and the polymorphism of the P. vivax multi-drug resistant gene (pvmdr1). RESULTS: Thirty P. vivax isolates were collected from Mauritania, Sudan, and Oman. Among the 28 P. vivax isolates successfully sequenced, only 4 samples showed the conserved His (372)-Cys (428) residues in PvMCA1-cd. Single nucleotide polymorphisms observed were H372T (46.4%), H372D (39.3%), and C428R (85.7%). A new polymorphic catalytic domain was observed at His (282)-Cys (305) residues. Sequences alignment analysis of pvmdr1 showed SNP in the three codons 958, 976 and 1076. A single SNP was identified at the codon M958Y (60%), 2 SNPs were found at the position 976: Y976F (13%) and Y976V (57%), and 3 SNPs were identified at the position 1076: F1076L (40%), F1076T (53%) and F1076I (3%). Only one isolate was wildtype in all three codons (MYF), 27% were single MYL mutants, and 10% were double MFL mutants. Three new haplotypes were also identified: the triple mutant YVT was most prevalent (53.3%) distributed in the three countries, while triple YFL and YVI mutants (3%), were only found in samples from Sudan and Mauritania. CONCLUSIONS: Triple or quadruple mutants for metacaspase genes and double or triple mutants for Pvmdr1 were observed in 24/28 and 19/28 samples. There was no difference in the frequency of mutations between PvMCA1-cd and Pvmdr1 (P > 0.2). Histidine and cysteine residues in PvMCA1-cd are highly polymorphic and linkage disequilibrium with SNPs of Pvmdr1 gene may be expected from these three areas with different patterns of P. vivax transmission.

Multilocus sequence typing analysis reveals that Cryptococcus neoformans var. neoformans is a recombinant population.

Cryptococcus neoformans var. neoformans (serotype D) represents about 30% of the clinical isolates in Europe and is present less frequently in the other continents. It is the prevalent etiological agent in primary cutaneous cryptococcosis as well as in cryptococcal skin lesions of disseminated cryptococcosis. Very little is known about the genotypic diversity of this Cryptococcus subtype. The aim of this study was to investigate the genotypic diversity among a set of clinical and environmental C. neoformans var. neoformans isolates and to evaluate the relationship between genotypes, geographical origin and clinical manifestations. A total of 83 globally collected C. neoformans var. neoformans isolates from Italy, Germany, France, Belgium, Denmark, Greece, Turkey, Thailand, Japan, Colombia, and the USA, recovered from different sources (primary and secondary cutaneous cryptococcosis, disseminated cryptococcosis, the environment, and animals), were included in the study. All isolates were confirmed to belong to genotype VNIV by molecular typing and they were further investigated by MLST analysis. Maximum likelihood phylogenetic as well as network analysis strongly suggested the existence of a recombinant rather than a clonal population structure. Geographical origin and source of isolation were not correlated with a specific MLST genotype. The comparison with a set of outgroup C. neoformans var. grubii isolates provided clear evidence that the two varieties have different population structures.

Impact of a change in protected environment on the occurrence of severe bacterial and fungal infections in children undergoing hematopoietic stem cell transplantation.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a procedure with a high infection risk. Strict isolation of patients is the rule to prevent such condition. OBJECTIVE: We compared the occurrence of severe infections (bacteremia and invasive fungal infection, IFI) in children undergoing alloHSCT before and after the move to a new protected unit with decreases in isolation methods. METHODS: The study was conducted over a 10-year period. Unit 1 (2002-2007) consisted of laminar airflow rooms where caregivers were required to wear a sterile outfit (gown, gloves, hat, and mask). Unit 2 (2008-2012) included spacious positive air pressure rooms with HEPA filters where only a clean gown and mask were required to be worn. RESULTS: Two hundred eighty-six alloHSCTs were performed (144 in Unit 1 and 142 in Unit 2). We reported a total incidence of 4.78 infections/1000 hospital-days including 4.4 episodes of bacteremia and 0.38 episodes of IFI. There was no statistical difference in the incidence of infections: n = 4.98/1000 hospital-days in Unit 1 vs. n = 4.6/1000 in Unit 2 (P = 0.63). CONCLUSION: The lack of difference in the occurrence of severe infection supports our decision to decrease unnecessary high protection in alloHSCT units to improve children's daily life.

7-Chloro-4-aminoquinoline γ-hydroxy-γ-lactam derived-tetramates as a new family of antimalarial compounds.

In this Letter we report on an efficient and short 2-3 steps synthesis of γ-hydroxy-γ-lactam derived-tetramates bearing a 7-chloro-4-aminoquinoline skeleton and their evaluation as potent antimalarials. These molecules were obtained through ring opening-ring closure (RORC) process of γ-ylidene-tetronate derivatives in the presence of 7-chloro-4-aminoquinoline-derived amines. In vitro antimalarial activity of these new γ-lactams was evaluated against Plasmodium falciparum clones of variable sensitivity (3D7 and W2) and they were found to be active in the range of 14-827nM with generally good resistance index. A preliminary SAR study is also presented to explain these results. Finally, the most active compounds did not show in vitro cytotoxicity when tested against Human Umbilical Vein Endothelial Cells (HUVEC) up to concentration of 50µM and they were stable at pH 7.4 for at least 48h.

Putative invasive pulmonary aspergillosis in critically ill patients with chronic obstructive pulmonary disease: a matched cohort study.

INTRODUCTION: Patients with advanced chronic obstructive pulmonary disease (COPD) are at risk for developing invasive pulmonary aspergillosis. A clinical algorithm has been validated to discriminate colonization from putative invasive pulmonary aspergillosis (PIPA) in Aspergillus-positive respiratory tract cultures of critically ill patients. We focused on critically ill patients with COPD who met the criteria for PIPA. METHODS: This matched cohort study included critically ill patients with COPD from two university hospital intensive care units (ICUs). We studied the risk factors for PIPA as well as the impact of PIPA on short- and long-term outcomes. Whether PIPA was associated with a pattern of bacterial colonization and/or infection 6 months before and/or during ICU stay was assessed. In addition, antifungal strategies were reviewed. RESULTS: Fifty cases of PIPA in critically ill patients with COPD in the ICU were matched with one hundred control patients with COPD. The ICU short- and the long-term (at 1 year) mortality were significantly increased in the PIPA group (p < 0.001 for all variables). PIPA was a strong independent risk factor for mortality in the ICU (odds ratio 7.44, 95 % confidence interval 2.93-18.93, p < 0.001) before vasopressor therapy, renal replacement therapy, and duration of mechanical ventilation. Before ICU admission, the use of corticosteroids and antibiotics significantly increased the risk of PIPA (p = 0.004 and p < 0.001, respectively). No significant difference in bacterial etiologic agents responsible for colonization and/or infection was found between the groups. Antifungal treatment was started in 64 % of PIPA cases, with a poor impact on the overall outcome. CONCLUSIONS: PIPA was a strong death predictor in critically ill patients with COPD. The use of corticosteroids and antibiotics before ICU admission was a risk factor for PIPA. PIPA was not associated with a specific bacterial pattern of colonization or infection. Prompting antifungal treatment in critically ill patients with COPD who have PIPA may not be the only factor involved in prognosis reversal.

Improvement in the Outcome of Invasive Aspergillosis in a Pediatric Hematology Department: A 10-Year Review.

BACKGROUND: Invasive aspergillosis (IA) is associated with a high mortality rate despite the introduction of new antifungal agents. Several therapeutic strategies have been proposed to improve mortality rates in IA, including combination of drugs. METHODS: Here, we report the outcome of treatments based on a combination of antifungal agents on IA, including voriconazole and liposomal amphotericin B, in a pediatric population from 2001 to 2010. Our population included children with diverse hematological diseases or with bone marrow transplantation. RESULTS: Over a 10-year period, we diagnosed 19 cases (2,8%) of invasive pulmonary aspergillosis with an overall survival rate of 58%. CONCLUSION: Compared with the previous study conducted from 1986 to 2000, the overall survival rate (bone marrow transplantation excluded) greatly improved (12.5% to 58%), especially for patients treated for acute leukemia.

Dermatophytes and transmission risks to family: a retrospective study of a cohort of 256 adopted children from 1998 to 2012.

In this 14-year retrospective study we analyzed samples collected from 101 adopted children originating from developing countries in search of dermatophytosis; a dermatophyte was isolated in 44 children. We demonstrated that dermatophytoses often have a silent clinical presentation (16%) and in approximately 20% of cases cause family member contamination. This study highlights the importance of the clinical examination of children and families as well as systematic sampling of children to avoid dermatophyte transmission to other family members.

Fungaemia caused by Fusarium proliferatum in a patient without definite immunodeficiency.

Recent literature has shown the growing importance of opportunistic fungal infections due to Fusarium spp. However, disseminated fusariosis remains rare in patients without neutropenia. We report a case of fungaemia in a 78-year-old French woman without definite immunodeficiency. Fusarium proliferatum grew from both central and peripheral blood cultures. Fever was the only clinical sign of the infection. An appropriate antifungal therapy with voriconazole led to the recovery of the patient. An environmental investigation was undertaken but failed to find a reservoir of Fusarium spores. A contaminated central venous catheter might have been the source of fungaemia.

Efficacy of intranasal administration of artesunate in experimental cerebral malaria.

BACKGROUND: Improving management of patients suffering from cerebral malaria is needed to reduce the devastating mortality and morbidity of the disease in endemic areas. Intravenous artesunate is currently the first-line treatment, but the lack of material and skills in the field make it difficult to implement in endemic areas. Intranasal route provides a very easy and direct gateway to blood and brain to deliver medications, by-passing the brain blood barrier. Therefore, it could be helpful and suitable to administer artesunate in the context of cerebral malaria, especially in young children. In this study, intranasal administration of artesunate to rescue from cerebral malaria using a murine model was tested. METHODS: CBA/J mice infected with Plasmodium berghei ANKA strain received artesunate (20 mg/kg) or a placebo solution intranasally, either on day 5, 6 or 7 post-infection, during a controlled, blinded, randomized trial. Primary endpoint was mortality on day 12 post-infection. Secondary endpoints were parasitaemia and clinical stage. Pharmacokinetics data following administration were collected in blood and brains of treated mice. Local toxicity was evaluated by histopathologic examination of brain and nasal sections in blinded manner. RESULTS: Intranasal administration of artesunate dramatically reduced the mortality rate (p < 0.001), preventing death in most cases. Parasitaemia loads decreased by 88.7% (61.8-100%) within 24 hours after administration. Symptoms of cerebral malaria were prevented or reversed. Dihydroartemisinin was detected in mice blood and brain within 15 minutes of intranasal administration. No direct nasal or brain toxicity was detected. CONCLUSION: Intranasal delivery is an efficient route to timely and efficiently administer artesunate and therefore may contribute to decreasing malaria-related mortality.

Specifically Targeting Metacaspases of Candida: A New Therapeutic Opportunity.

The World Health Organization (WHO) recently published a list of fungal priority pathogens, including Candida albicans and C. auris. The increased level of resistance of Candida is raising concern, considering the availability of only four classes of medicine. The WHO is seeking novel agent classes with different targets and mechanisms of action. Targeting Candida metacaspases to control intrinsic cell death could provide new therapeutic opportunities for invasive candidiasis. In this review, we provide the available evidence for Candida cell death, describe Candida metacaspases, and discuss the potential of Candida metacaspases to offer a new specific target. Targeting Candida cell death has good scientific rationale given that the fungicidal activity of many marketed antifungals is mediated, among others, by cell death triggering. But none of the available antifungals are specifically activating Candida metacaspases, making this target a new therapeutic opportunity for non-susceptible isolates. It is expected that antifungals based on the activation of fungi metacaspases will have a broad spectrum of action, as metacaspases have been described in many fungi, including filamentous fungi. Considering this original mechanism of action, it could be of great interest to combine these new antifungal candidates with existing antifungals. This approach would help to avoid the development of antifungal resistance, which is especially increasing in Candida.

Nanoparticle tracking analysis of natural hemozoin from Plasmodium parasites.

BACKGROUND: Hemozoin is a byproduct of hemoglobin digestion crucial for parasite survival. It forms crystals that can be of interest as drug targets or biomarkers of malaria infection. However, hemozoin has long been considered as an amorphous crystal of simple morphology. Studying the consequences of biomineralization of this crystal during the parasite growth may provide more comprehensive evidence of its role during malaria. OBJECTIVES: This study aimed to investigate the interest of nanoparticles tracker analysis for measuring the concentration and size of hemozoin particles produced from different parasite sources and conditions. METHODS: Hemozoin was extracted from several clones of Plasmodium falciparum both asexual and sexual parasites. Hemozoin was also extracted from blood samples of malaria patients and from saliva of asymptomatic malaria carriers. Nanoparticles tracking analysis (NTA) was performed to assess the size and concentration of hemozoin. RESULTS: NTA data showed variation in hemozoin concentration, size, and crystal clusters between parasite clones, species, and stages. Among parasite clones, hemozoin concentration ranged from 131 to 2663 particles/infected red blood cell (iRBC) and size ranged from 149.6 ± 6.3 nm to 234.8 ± 40.1 nm. The mean size was lower for Plasmodium vivax (176 ± 79.2 nm) than for Plasmodium falciparum (254.8 ± 74.0 nm). Sexual NF54 parasites showed a 7.5-fold higher concentration of hemozoin particles (28.7 particles/iRBC) compared to asexual parasites (3.8 particles/iRBC). In addition, the mean hemozoin size also increased by approximately 60 % for sexual parasites. Compared to in vitro cultures of parasites, blood samples showed low hemozoin concentrations. CONCLUSIONS: This study highlights the potential of NTA as a useful method for analyzing hemozoin, demonstrating its ability to provide detailed information on hemozoin characterization. However, further research is needed to adapt the NTA for hemozoin analysis.