Duffy blood system and g6pd genetic variants in p. Vivax malaria patients from manaus, amazonas, brazil

Background Over a third of the world’s population lives at risk of potentially severe Plasmodium vivax induced malaria. The unique aspect of the parasite’s biology and interactions with the human host make it harder to control and eliminate the disease. Glucose-6-phosphate dehydrogenase (G6PD) deficiency and Duffy-negative blood groups are two red blood cell variations shown to confer protection against malaria. Methods Molecular genotyping of G6PD and Duffy was performed in 225 patients with severe and non-severe malaria randomly admitted at a reference center for infectious disease from Manaus. For G6PD variants characterization of the variants, Real Time PCR (qPCR) was performed, while Duffy genotyping by PCR-RFLP. Results Of the 225 patients, 29 (12.94%) and 43 (19.19%) were carriers of the G6PD c.202G > A and c.376A > G, respectively. For the Duffy genotype (c.-67T > C in the GATA promoter region), 70 (31.11%) were phenotyped as Fy(a + b-), 98 (43.55%) Fy(a + b+), 56 (24.9%) Fy(a-b+) and 1 (0.44%) Fy(a-b-). The FY*01/FY*02 genotype was prevalent in both non-severe and severe malaria. In women, the FY*01/FY*02 allele occurred concomitantly with c.376A > G more frequently in non-severe malaria, while in men, this combination was predominant in severe malaria. Duffy phenotype Fy(a-b+) (p = 0.022) and genotypes FY*01/FY*01 / FY*02/FY*02 (p = 0.015) correlated with high parasitemia density before and after treatment. Conclusions Our results showed only one uncomplicated vivax malaria patient with Duffy phenotype Fy(a-b-). Heterozygous GATA variants did not confer protection against malaria infection in this study. Research on G6PD and Duffy antigen deficiencies has been valuable, particularly when focused on densely populated areas. Our results confirm possible genetic molding mechanisms in vivax malaria in our Amazon region and can help to improve the understanding of the relationship between G6PD deficiency and Duffy genotypes concomitantly in the protection or susceptibility to P. vivax infection. Molecular diagnosis before treatment may be necessary in the Amazonian population, regardless of the diagnosis of uncomplicated or severe malaria.

Circulating cytokine and chemokine profiles of Trypanosoma cruzi-infected women during pregnancy and its association with congenital transmission

Background Trypanosoma cruzi, the causative agent of Chagas disease, can be transmitted to the offspring of infected women, which constitutes an epidemiologically significant parasite transmission route in non-endemic areas. It is relevant to evaluate differentially expressed factors in T. cruzi-infected pregnant women as potential markers of Chagas congenital transmission. Methods Circulating levels of twelve cytokines and chemokines were measured by ELISA or cytometric bead array in T. cruzi-infected and uninfected pregnant women in their second trimester of pregnancy, and control groups of T. cruzi-infected and uninfected non-pregnant women. Results T. cruzi-infected women showed a pro-inflammatory Th1-biased profile, with increased levels of TNF-α, IL-12p70, IL-15 and MIG. Uninfected pregnant women presented a biased response towards Th2/Th17/Treg profiles, with increased plasma levels of IL-5, IL-6, IL-1β, IL-17A and IL-10. Finally, we identified that high parasitemia together with low levels of TNF-α, IL-15, and IL-17, low TNF-α/IL-10 ratio, and high IL-12p70 levels are factors associated with an increased probability of Chagas congenital transmission. Conclusions T. cruzi-infected pregnant women who did not transmit the infection to their babies exhibited a distinct pro-inflammatory cytokine profile that might serve as a potential predictive marker of congenital transmission.

Improved Protocol for Continuous Culture of Plasmodium falciparum Reference Strains

Parasitic biobank of Plasmodium falciparum is almost germinal in Côte d’Ivoire. However, several high-level research topics on this parasite involve the taking into account of nature isolates but also chemo-sensitive or resistant reference strains for a better validation of results. In addition, acquisition of these reference strains is still arduous for laboratories in developing countries due to complexity of administrative procedures. For those reasons, this study aimed in to combine several procedures into a consolidated one in order to enhance the multiplication of P. falciparum reference strains. Continuous culture of plasmodial strains was based on the Trager and Jensen procedures. The CELL culture protocols used are those of the Swiss TPH described by Sergio Wittlin; the “Growing Plasmodium falciparum cultures at high parasitemia” and the “Stockholm sorbitol method” of Methods in Malaria Research-6th edition 2013; and the INV-01 and INV-02 procedures of the Worldwide Antimalarial Resistance Network (WWARN). Reference Plasmodium falciparum strains NF54 sensitive to chloroquine (CQs) and K1 resistant to chloroquine (CQr) were received from the Swiss Tropical Institute and Public Health (Swiss TPH). The CQs NF54 strain reacted more quickly to the protocol unlike the CQr K1 strain. Parasitic densities (DP) obtained with NF54 strain were ranged from 0.4% at day zero (D0) to 11.4% at day eight (D8). Strain K1 finally adapted successfully after one month of follow-up. Related DPs ranged from less than 0.1% to more than 20% in just three growth cycles after adaptation. A joint protocol (from this work) called “CRLP-SwissTPH-Pasteur_001” is available and allows to efficiently multiply reference strains NF54 and K1. It is planned to spread out the tests to other plasmodial strains as well as to wild isolates in order to standardize this procedure.

Transplacental Transmission of Theileria equi Is Not a Common Cause of Abortions and Infection of Foals in Israel

Although the main route of transmission of Theileria equi is through tick feeding, transplacental transmission is also possible and may lead to abortion, or to the birth of a sick or carrier foal. The aim of this study was to evaluate the role of T. equi as a cause of abortions in Israel and the risk of foals being infected at a young age. Eight aborting mares were serologically evaluated for exposure to T. equi via the immunofluorescence antibody test (IFAT) and their aborted fetuses were evaluated using PCR and qPCR. In addition, five mares and their foals (aged 4–6 months) from a highly endemic farm were tested for T. equi infection using IFAT, PCR and qPCR. Five of the eight aborting mares were seropositive for T. equi; however, none of the aborted fetuses was infected. All five mares from the endemic farm were subclinically infected with T. equi. Of their five foals, one was infected, with relatively high parasitemia and different parasite genotype than its dam’s, suggesting another source of infection. The results of this study suggest that transplacental transmission of T. equi is not common and does not appear to be a prominent cause of abortion in chronically infected mares.

Frequency of Hypoglycemia in Severe Malaria in Children Aged 5 To 144 Months In Kinshasa

Background: Hypoglycemia is an important complication of severe malaria, especially in children and pregnant women. In 2017 Kikimi hospital changed quinine treatment policy from 15 mg/kg loading (plus 10 mg/kg 12-hourly) to 20 mg/kg loading (plus 10 mg/kg 8-hourly) to comply with new WHO guidelines. This presented us with the opportunity to examine whether there was any dose relationship of quinine and hypoglycemia occurrence, in particular, in severe malaria in children from 5 to 144 months. Methods: The study was retrospective of children aged 5 to 144 months admitted to KIkimi hospital with severe malaria between April 2017 and July 2018, before and after the introduction of the new quinine treatment regimen by the WHO. The patient's blood glucose at four hours was measured until intravenous quinine was stopped. Clinical events immediately before or simultaneously with each episode of hypoglycemia (glucose <= 3.0 mmol / l) were recorded. Results: Age group at high parasitemia was 13 to 48 months and165 children received the old quinine diet and 125 the new diet. We found no evidence of an increase in the prevalence of hypoglycemia (<= 3.0 mmol / L) with the new regimen compared with the old one (15% versus 15%); similar results were noted for deep hypoglycaemia (<2.2 mmol / L) 9% v 6%, p = 0.09. The episodes coincided with the indicators of the severity of the disease: coma (55%), circulatory insufficiency (36%) and respiratory distress (19%), but less frequently with convulsions (11). Conclusion: With a single case of malaria falciparum infection with high parasitemia in children aged 13 to 48 months. There was no evidence to indicate a dose relationship between quinine and the occurrence of hypoglycemia. Hypoglycemia was associated with disruption of glucose perfusion and transfusion. Close monitoring of blood glucose should be targeted during complications in children who remain seriously ill.

Parasite-Mediated Degradation of Synthetic Ozonide Antimalarials ImpactsIn VitroAntimalarial Activity

ABSTRACTThe peroxide bond of the artemisinins inspired the development of a class of fully synthetic 1,2,4-trioxolane-based antimalarials, collectively known as the ozonides. Similar to the artemisinins, heme-mediated degradation of the ozonides generates highly reactive radical species that are thought to mediate parasite killing by damaging critical parasite biomolecules. We examined the relationship between parasite dependent degradation and antimalarial activity for two ozonides, OZ277 (arterolane) and OZ439 (artefenomel), using a combination ofin vitrodrug stability and pulsed-exposure activity assays. Our results showed that drug degradation is parasite stage dependent and positively correlates with parasite load. Increasing trophozoite-stage parasitemia leads to substantially higher rates of degradation for both OZ277 and OZ439, and this is associated with a reduction inin vitroantimalarial activity. Under conditions of very high parasitemia (∼90%), OZ277 and OZ439 were rapidly degraded and completely devoid of activity in trophozoite-stage parasite cultures exposed to a 3-h drug pulse. This study highlights the impact of increasing parasite load on ozonide stability andin vitroantimalarial activity and should be considered when investigating the antimalarial mode of action of the ozonide antimalarials under conditions of high parasitemia.

Association between Plasmodium falciparum parasite index and renal function in children

Background Falciparum malaria is an acute systemic diseasethat can cause multi organ disorders including in kidney. The aimof this study was to figure out the association between P.falciparumparasite index and renal function in children by measuring ureum,creatinine, and glomerular filtration rate (GFR).Methods An analytic prospective study was conducted on all hos-pitalized falciparum malaria patients in the Department of ChildHealth, Manado Central General Hospital from November 2001-February 2002. Low parasitemia was defined if P.falciparum foundwas ≤100/100 fields and high parasitemia if >1/1 field. Data wereanalyzed by chi-square and student t–test.Results Among 34 patients, there were 11 with high parasitemiaand 23 with low parasitemia. There were 19 with increased ureumand 8 with increased creatinine. There was significant elevation ofureum in high parasitemia (n=10) compared to that in low para-sitemia patients (n=9) with p=0.004. The increase of serum creati-nine was found in 2 high parasitemia and in 6 low parasitemiapatients (p=0.611). Mean GFR was 107.63±30.62 in high and121.94±44.06 in low parasitemia patients (p=0.341).Conclusion There was a significant association betweenP.falciparum parasite index and serum ureum. But there was nosignificant association between parasite index and creatinine orGFR

Atovaquone and ELQ-300 Combination Therapy as a Novel Dual-Site Cytochromebc1Inhibition Strategy for Malaria

ABSTRACTAntimalarial combination therapies play a crucial role in preventing the emergence of drug-resistantPlasmodiumparasites. Although artemisinin-based combination therapies (ACTs) comprise the majority of these formulations, inhibitors of the mitochondrial cytochromebc1complex (cytbc1) are among the few compounds that are effective for both acute antimalarial treatment and prophylaxis. There are two known sites for inhibition within cytbc1: atovaquone (ATV) blocks the quinol oxidase (Qo) site of cytbc1, while some members of the endochin-like quinolone (ELQ) family, including preclinical candidate ELQ-300, inhibit the quinone reductase (Qi) site and retain full potency against ATV-resistantPlasmodium falciparumstrains with Qosite mutations. Here, we provide the firstin vivocomparison of ATV, ELQ-300, and combination therapy consisting of ATV plus ELQ-300 (ATV:ELQ-300), usingP. yoeliimurine models of malaria. In our monotherapy assessments, we found that ATV functioned as a single-dose curative compound in suppressive tests whereas ELQ-300 demonstrated a unique cumulative dosing effect that successfully blocked recrudescence even in a high-parasitemia acute infection model. ATV:ELQ-300 therapy was highly synergistic, and the combination was curative with a single combined dose of 1 mg/kg of body weight. Compared to the ATV:proguanil (Malarone) formulation, ATV:ELQ-300 was more efficacious in multiday, acute infection models and was equally effective at blocking the emergence of ATV-resistant parasites. Ultimately, our data suggest that dual-site inhibition of cytbc1is a valuable strategy for antimalarial combination therapy and that Qisite inhibitors such as ELQ-300 represent valuable partner drugs for the clinically successful Qosite inhibitor ATV.