Increase In Parasite Density Research Articles

Buffalo colostrum- A novel substitute of human serum for the cultivation of Plasmodium falciparum in vitro

In vitro cultivation of erythrocytic stages of Plasmodium falciparum requires supplementing the culture medium with human serum. The present study was carried out to explore an alternative to human serum. Different human serum samples were found to vary considerably in their ability to support the growth of erythrocytic stages of P. falciparum in vitro. These results strongly suggested the use of pooled human serum for comparing the growth of parasites in medium augmented with other supplements. Parasites could multiply for a few cycles only in RPMI (Roswell Park Memorial Institute) medium supplemented with serum obtained from pig, goat, sheep or buffalo. Continued cultivation could not be achieved using any one of these animal sera. Ability of bovine colostrum was investigated as an alternative to human serum. Buffalo colostrum, 10%(v/v) 'suitably prepared' supported the continuous growth and multiplication of P. falciparum . Morphologically both asexual and sexual stages appeared normal and healthy, but the multiplication rate of parasites grown in colostrum augmented medium was found to be lower than that in serum-supplemented medium. The one month of uninterrupted cultivation of P. falciparum registered 106 fold increase in parasite density compared to 1010 fold multiplication recorded in control culture with 10% serum supplement. Cow colostrum failed to support the growth and multiplication of parasites beyond 6 days in culture. The initial positive results with buffalo colostrum hold promise and should be explored further as a potential substitute for human serum for continuous in vitro propagation of erythrocytic stages of the malignant malaria parasite.

Fish vulnerability to capture by trapping is modulated by individual parasite density.

Commercial fishery harvest is a powerful evolutionary agent, but we know little about whether environmental stressors affect harvest-associated selection. We test how parasite infection relates to trapping vulnerability through selective processes underlying capture. We used fish naturally infected with parasites, including trematodes causing black spots under fish skin. We first assessed how individual parasite density related to standard metabolic rate (SMR), maximum metabolic rate (MMR) and absolute aerobic scope (AAS)-then used laboratory fishing simulations to test how capture vulnerability was related to parasite density. We further explored group-trapping dynamics using experimental shoals containing varying proportions of infected fish (groups of six with either 0, 2, 4 or 6 infected individuals). At the individual level, we found a positive relationship between parasite presence and SMR, but not MMR or AAS. While we saw no relationship between individual metabolic capacity and vulnerability to trapping, we found the length of time fish spent in traps increased with increasing parasite density, a predictor of trapping-related capture probability. At the group level, the number of infected individuals in a shoal did not affect overall group trapping vulnerability. Our results suggest that parasite infection has some capacity to shift individual vulnerability patterns in fisheries, and potentially influence the evolutionary outcomes of fisheries-induced evolution.

Gravidity and malaria trends interact to modify P. falciparum densities and detectability in pregnancy: a 3-year prospective multi-site observational study

BackgroundLow-density Plasmodium falciparum infections prevail in low transmission settings, where immunity is expected to be minimal, suggesting an immune-independent effect on parasite densities. We aimed to describe parasite densities in pregnancy, and determine how gravidity and antibody-mediated immunity affect these, during a period of declining malaria transmission in southern Mozambique.MethodsWe documented P. falciparum infections at first antenatal care visits (n = 6471) between November 2016 and October 2019 in Ilha Josina (high-to-moderate transmission area), Manhiça (low transmission area), and Magude (pre-elimination area). Two-way interactions in mixed-effects regression models were used to assess gravidity-dependent differences in quantitative PCR-determined P. falciparum positivity rates (PfPRqPCR) and densities, in the relative proportion of detectable infections (pDi) with current diagnostic tests (≥ 100 parasites/μL) and in antimalarial antibodies.ResultsPfPRqPCR declined from 28 to 13% in Ilha Josina and from 5–7 to 2% in Magude and Manhiça. In primigravidae, pDi was highest in Ilha Josina at the first study year (p = 0.048), which declined with falling PfPRqPCR (relative change/year: 0.41, 95% CI [0.08; 0.73], p = 0.029), with no differences in antibody levels. Higher parasite densities in primigravidae from Ilha Josina during the first year were accompanied by a larger reduction of maternal hemoglobin levels (− 1.60, 95% CI [− 2.49; − 0.72; p < 0.001), than in Magude (− 0.76, 95% CI [− 1.51; − 0.01]; p = 0.047) and Manhiça (− 0.44, 95% CI [− 0.99; 0.10; p = 0.112). In contrast, multigravidae during the transmission peak in Ilha Josina carried the lowest pDi (p = 0.049). As PfPRqPCR declined, geometric mean of parasite densities increased (4.63, 95% CI [1.28; 16.82], p = 0.020), and antibody levels declined among secundigravidae from Ilha Josina.ConclusionsThe proportion of detectable and clinically relevant infections is the highest in primigravid women from high-to-moderate transmission settings and decreases with declining malaria. In contrast, the falling malaria trends are accompanied by increased parasite densities and reduced humoral immunity among secundigravidae. Factors other than acquired immunity thus emerge as potentially important for producing less detectable infections among primigravidae during marked declines in malaria transmission.

Spatiotemporal distribution of Ceratonova shasta in the lower Columbia River Basin and effects of exposure on survival of juvenile chum salmon Oncorhynchus keta.

In the Columbia River Basin (CRB), USA, anthropogenic factors ranging from dam construction to land use changes have modified riverine flow and temperature regimes and degraded salmon habitat. These factors are directly implicated in native salmon and steelhead (Oncorhynchus species) population declines and also indirectly cause mortality by altering outcomes of ecological interactions. For example, attenuated flows and warmer water temperatures drive increased parasite densities and in turn, overwhelm salmonid resistance thresholds, resulting in high disease and mortality. Outcomes of interactions between the freshwater myxozoan parasite, Ceratonova shasta, and its salmonid hosts (e.g., coho O. kisutch and Chinook salmon O. tshawytscha) are well-described, but less is known about effects on chum salmon O. keta, which have a comparatively brief freshwater residency. The goal of this study was to describe the distribution of C. shasta relative to chum salmon habitat in the CRB and assess its potential to cause mortality in juvenile chum salmon (listed as threatened in the CRB under the U.S. Endangered Species Act). We measured C. shasta densities in water samples collected from chum salmon habitat throughout the lower CRB during the period of juvenile chum salmon outmigration, 2018–2020. In 2019, we exposed caged chum salmon fry from two hatchery stocks at three C. shasta-positive sites to assess infection prevalence and survival. Results demonstrated: (1) C. shasta was detected in spawning streams from which chum salmon have been extirpated but was not detected in contemporary spawning habitat while juvenile chum salmon were present, (2) spatiotemporal overlap occurs between C. shasta and juvenile chum salmon in the Columbia River mainstem, and (3) low densities of C. shasta caused lethal infection in chum salmon fry from both hatchery stocks. Collectively, our results suggest C. shasta may limit recovery of chum salmon now and in the future.

Effect of Phototherapy on Demodex Parasıte Densıty.

Demodex parasites are the most common ectoparasites in humans. One of the factors in the pathogenesis of an increase in parasite density is immunosuppression. In this prospective study, we aimed to evaluate the effect of phototherapy-induced immunosuppression on Demodex density. Thirty-five patients receiving phototherapy were included in the study. The number of parasites in the samples taken from the right cheek, left cheek, forehead, nose and chin of the patients, by standardized skin surface biopsy method, were recorded before phototherapy and in the third month of treatment. Of the 35 patients, the female-to-male ratio was found to be 2.1:1. There was no statistically significant difference between the ages of the male and female patients. The increase in the number of parasites in the right cheek, left cheek, nose and chin in the third month was statistically significant; whereas the increase in the forehead was not. The results of our study showed that phototherapy can cause an increase in Demodex density, and these findings are compatible with those of other studies in the literature. Since our study aims to evaluate density at the beginning and the end of the third month of phototherapy, it differs from other studies by indicating the effect of phototherapy more accurately.

B-lines by lung ultrasound is associated with pulmonary symptoms and cardiac function in acute malaria: a prospective cohort study

Abstract Background Malaria patients are at risk of cardiopulmonary complications, but diagnosis and management are difficult in resource limited environments. B-lines by lung ultrasonography (LUS) can identify pulmonary alterations, however, little is known about the usefulness in malaria. Purpose We aimed to investigate the occurrence of B-lines in acute malaria patients at baseline and at follow-up, and whether they are associated with shortness of breath and impaired left ventricular ejection fraction (LVEF). Methods Adult patients with non-severe acute malaria were prospectively enrolled from June to December 2020 in community healthcare clinics in a remote area. Patients were age- and sex-matched to controls without a prior history of malaria. We examined patients prior to anti-malaria treatment and at follow-up. Malaria treatment was administered according to national guidelines. Patients were excluded if they were pregnant, had concomitant infections or recent chest trauma. Patients underwent LUS (8-zones), echocardiography and peripheral blood smear. Measurements were blinded to clinical variables and outcomes. Results We included a total of 99 patients (median age 40±15 years, 55% men). Patients suffered from Plasmodium vivax (n=75), P. falciparum (n=22), and a mix of the two (n=2) and median parasite density was 1,595 parasites/mL (interquartile range [IQR] 528–6,585/mL). Follow-up was completed in 71 patients and the median follow-up time was 31 days (IQR 27–40 days). Patients with acute malaria had significantly more B-lines at baseline than matched controls (P-value&amp;lt;0.001) and fewer B-lines at follow-up (P-value&amp;lt;0.001) (Figure 1). In acute malaria patients, number of B-lines at baseline correlated significantly with shortness of breath (OR 1.20, [1.04 to 1.39], P-value=0.01) and with LVEF (adjusted for age and sex: +8% [+1% to +15%], P-value=0.016 per 1% decrease in LVEF). There was no correlation between number of B-lines and parasite density (+2% [−5% to +11%], P-value=0.53 per 1000 increase in parasite density). Conclusion B-lines detected by LUS are more frequent in patients with acute malaria than in age- and sex-matched controls and decrease in response to treatment. B-lines also correlate with shortness of breath and lower LVEF at baseline. Because LUS is a quick and accessible examination, it may potentially facilitate risk stratification and therapeutic decisions regarding cardiopulmonary complications in patients with acute malaria. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Danish Heart Association

Plasmodiasis in Relation to Haematological Parameters among Children in the Internally Displaced Persons Camps (IDPS) within Maiduguri, Nigeria

Introduction: Malaria parasite is a protozoan disease that is transmitted by female anopheles mosquito which infects humans regardless of age, sex and status. It has a worldwide distribution and often prevalent in the developing countries and areas with poor environmental hygiene this study focuses on the incidence of plasmodiasis in relation to haematological parameters among children in the Internally Displaced Persons (IDPs) camp.&#x0D; Methods: blood samples were collected via venipuncture for thick blood film and was stained with giemsa diluted 1:10 and rapid diagnostic techniques (RDT), while the hematological parameter were analyzed by auto analyzer machine.&#x0D; Results: a total of two hundred and one (201) samples were obtained from two different camps in the study area. 87 were obtained from Stadium IDPs camp and 114 from Bakassi camp. From the Stadium IDPs camp 25(12.4%) were malaria positive and 62(30.8%) were negative. Similarly, from Bakassi IDPs camp, 58(28.9%) were positive and 56(27.9%) were negative.&#x0D; Conclusions: Males were shown to have eosinophilia compared to the females, due to an increase in the eosinophil count in them which can be used to predict the intensity of malaria infection, and a decrease in the eosinophil in females. There was a partial negative correlation due to a decrease in the monocyte and lymphocyte with increasing parasite density count.

Associations of Single Nucleotide Polymorphisms in IL-18 Gene with Plasmodium falciparum-Associated Malaria

IntroductionInterleukin-18 (IL-18) is a pro-inflammatory cytokine, reported to be involved in the initial immune responses against malaria. Genetic variations in the host are an important factor that influences the etiology of malaria at several disease levels. Polymorphisms within the IL-18 gene are associated with susceptibility and clinical outcome of several diseases.MethodsWe genotyped single nucleotide polymorphisms (SNPs) in IL-18 of patients infected with Plasmodium falciparum with varying extent of parasitemia and different age groups.ResultsSNPs rs5744292 (OR = 70.446; 95% CI = 4.318–1149.323; p<0.0001) and rs544354 (OR = 1.498; 95% CI = 1.088–2.063; p=0.013) were found to be significantly associated with parasitemia in P. falciparum-infected patients when compared with healthy control subjects. SNP rs5744292 (OR = 7.597; 95% CI=1.028–56.156; p=0.019) was associated with increased parasite density in infected patients. SNPs rs544354 (OR 0.407; 95% CI=0.204–0.812; p = 0.009) and rs360714 (OR of 0.256; 95% CI=0.119–0.554; p = 0.001) were significantly associated with parasite density in an age-dependent manner, with the risk alleles present more frequently among the younger (1–9 years) patients. Several haplotypes were found to have a significant association with parasitemia. In-vitro expression analysis using luciferase reporter assay showed that SNPs rs1946518 and rs187238 in the IL-18 gene promoter region and rs360728 and rs5744292 in the 3ʹ-untranslated region of the IL-18 gene were associated with enhanced transcriptional activity.ConclusionOur results suggest that polymorphisms within the IL-18 gene are associated with the susceptibility to P. falciparum infection and related parasitemia among groups with different parasite density and across various age groups.

Haematological Profile of Adults with Malaria Parasitaemia Visiting the Volta Regional Hospital, Ghana.

Background Malaria is known to cause severe health consequences due to its marked effects and alteration on the haematological parameters of infected individuals. This study evaluated the haematological profile of adult individuals infected with the malaria parasite. Methods A retrospective study was conducted using archived data of malaria positive cases from January 2017 to March 15, 2019. Data retrieved included subjects' demographics, malaria parasite count, malaria parasite species, and full blood count parameters. A total of 236 malaria positive subjects were included in the study. Results The study showed that more females were infected with the malaria parasite than males (69.07% and 30.93%, respectively). A total of 87.3% of the study population were infected with Plasmodium falciparum as compared to 12.7% infected with Plasmodium malariae. The commonest haematological abnormalities that were seen in this study were lymphopenia (56.78%), anaemia (55.51%), thrombocytopenia (47.46%), eosinopenia (45.76%), neutropenia (29.24%), monocytosis (21.19%), and leucocytosis (17.37%) in the infected subjects. The mean platelet count of P. falciparum-infected subjects was decreased as compared to the mean platelet count of P. malariae-infected subjects. There was a significant (P value <0.05) decrease in the number of platelet count with every unit increase in parasite density. Conclusion Study participants infected with malaria demonstrated vital changes in haematological parameters with anaemia, thrombocytopenia, lymphopenia, monocytosis, and eosinopenia being the most important predictors of malaria infection especially with P. falciparum species.P. falciparum-infected subjects was decreased as compared to the mean platelet count of

Possible evidence of gluconeogenesis in Plasmodium- Infected children in relationship with the parasite density

Background: Gluconeogenesis is stimulated by low blood glucose to maintain the glucose level; it involves lipolysis (breaking down of triglycerides), release of cortisol, and production of glycerol which can be converted into glucose. Hypoglycemia is associated with Plasmodium infection in children. Glucose homeostasis also involves glycogenolysis. This work was designed to determine the possible evidence of gluconeogenesis in Plasmodium-infected children in relationship with the parasite density to provide the information for useful direction in the management of Plasmodium infection in children. Methods: Thirty-five (2–5 years; female – 14, male – 11) Plasmodium-infected children were recruited as test patients, while fifty (n = 50; female – 25, male – 23) age-matched children (Plasmodium-noninfected children) were recruited from the same environment as controls. Plasma cortisol and cortisol-binding globulin were measured by the ELISA; total bile acid, glycerol by spectrophotometry, glucose, and total triglycerides were measured using Cobas C111, while Plasmodium identification and density were carried out by Leishman's thin blood film technique. Results: The results obtained showed a significant increase in plasma cortisol, cortisol-binding globulin, total bile acid, and glycerol with increase in parasite density and in children with the parasite densities of 512 ± 4.0 and 1014 ± 6.0 than the control children (P

Brain-encysting trematodes (Euhaplorchis californiensis) decrease raphe serotonergic activity in California killifish (Fundulus parvipinnis).

ABSTRACTModulation of brain serotonin (5-HT) signalling is associated with parasite-induced changes in host behaviour, potentially increasing parasite transmission to predatory final hosts. Such alterations could have substantial impact on host physiology and behaviour, as 5-HT serves multiple roles in neuroendocrine regulation. These effects, however, remain insufficiently understood, as parasites have been associated with both increased and decreased serotonergic activity. Here, we investigated effects of trematode Euhaplorchis californiensis metacercariae on post-stress serotonergic activity in the intermediate host California killifish (Fundulus parvipinnis). This parasite is associated with conspicuous behaviour and increased predation of killifish by avian end-hosts, as well as inhibition of post-stress raphe 5-HT activity. Until now, laboratory studies have only been able to achieve parasite densities (parasites/unit host body mass) well below those occurring in nature. Using laboratory infections yielding ecologically relevant parasite loads, we show that serotonergic activity indeed decreased with increasing parasite density, an association likely indicating changes in 5-HT neurotransmission while available transmitter stores remain constant. Contrary to most observations in the literature, 5-HT activity increased with body mass in infected fish, indicating that relationships between parasite load and body mass may in many cases be a real underlying factor for physiological correlates of body size. Our results suggest that parasites are capable of influencing brain serotonergic activity, which could have far-reaching effects beyond the neurophysiological parameters investigated here.

Density‐independent reproductive success of the hemiparasitic plant Striga hermonthica, despite positive and negative density‐dependent phases

AbstractThe hemiparasite Striga hermonthica is a major constraint to smallholder farmer livelihoods and food security in sub‐Saharan Africa. A better understanding of its life‐cycle can help developing more effective management strategies. Here, we studied density dependence in S. hermonthica on Sorghum bicolor. We exposed two genotypes of S. bicolor that differed in the level of tolerance and resistance to S. hermonthica to a range of seed densities of the parasite. We evaluated multiple host and parasite performance parameters through periodic, destructive harvests and related these to the initial seed density using model selection. Initially, the probability for attachment was positively density‐dependent, suggesting facilitation of new infections. However, at host maturity, S. hermonthica infection probability showed strong negative density dependence, indicating severe competition, in particular in the early developmental stages. Although parasite shoot dry weight showed a strong negative density dependence at host maturity, flower production per parasite exhibited positive density dependence again, suggesting compensation. The two host genotypes had similar responses to increased parasite densities, indicating differences between the genotypes in tolerance but not resistance. Consequently, despite density dependence in life‐cycle components, the per capita reproductive output of S. hermonthica, R0 (flowers seed−1) was density‐independent. Apparently, management of the hemiparasite can neither benefit from a negatively density‐dependent bottleneck, nor from a positively density‐dependent Allee effect. The most promising suggestion to obtain S. hermonthica population decline (R0 &lt; 1) and long‐term control is to increase host shading by growing a vigorous, competitive crop.

Sensitivity and Specificity of Clear View Malaria Dual Rapid Test® among Children Attending Hospital in Sengerema District, North-Western Tanzania

Malaria cases management and treatment need to have accurate and reliable diagnostic tools. Thus the present study evaluated the sensitivity and specificity of the test against expert microscopy in febrile under-five children in Sengerema District, north-western Tanzania. A finger prick blood sample was obtained from each child, and thin and thick blood smears were prepared, stained with 10% Giemsa and examined under the light microscope and ClearView Malaria Dual rapid test. A total of 232 children were included in the study. Of these, 29 (12.50%, 95%CI, 8.20-16.8) children had a positive malaria microscopy and 44 (18.97%, 95%CI, 13.9-23.9) were positive in the rapid diagnostic test. The sensitivity of the rapid diagnostic test increased with increasing P. falciparum geometric mean parasite density from 46.43% (95%CI, 39.72-53.1) at <200 parasites/μL to 93.75% (95%CI, 90.50-97.01) at ≥ 200 parasites/μL. ClearView Malaria Dual rapid test is highly specific and its sensitivity increases with increase in parasite density. The test could be used in holoendemic areas but its use in areas with low malaria transmission needs further evaluation.

Hyalournan Role in Pathophysiology of Different Species of Plasmodium

Background For years, Plasmodium vivax has been considered the cause of benign malaria. Nevertheless, it has been observed that this parasite can produce a severe disease comparable with Plasmodium falciparum. It has been suggested that some physiopathogenic processes might be shared by these 2 species, such as cytoadherence. Objective This study was conducted to demonstrate the severity of the disease with the hyaluronic acid (HA) level with different species of Plasmodium in patients complaining of fever of unknown origin, highly suspected clinically to be caused by malaria, which were diagnosed by microscopic examination, OptiMAL rapid antigen test, and serum level of HA and were assessed. Subjects and Methods A total of 32 expatriate patients attending King Faisal Specialized Hospital, Taif, Kingdom of Saudi Arabia, complaining of fever of unknown origin were examined for malaria parasites by microscopy of Giemsa-stained blood smears, OptiMAL rapid antigen test, and HA test. The diagnostic performance of these methods was statistically compared. Results Of 32 clinically suspected cases, 17 (53%) were positive for Plasmodium infection, and of these, 8 (47%) were infected by P. falciparum (G1) and 9 (53%) by P. vivax (G2). Fifteen (47%) were negative for Plasmodium species (G3). The differences in the level of HA were statistically significant in G1 as compared with G3 as well as G2 as compared with G3 and statistically insignificant in G2 as compared with G1 (P &gt; 0.05). Conclusions The association of severity of anemia and the trend observed between adhesion to HA and increased parasite densities suggest their potential contribution to sequestration observed in P. vivax infections.

Eicosapentaenoic Acid Modulates Trichomonas vaginalis Activity.

Trichomonas vaginalis is a sexually transmitted parasite and, while it is often asymptomatic in males, the parasite is associated with disease in both sexes. Metronidazole is an effective treatment for trichomoniasis, but resistant strains have evolved and, thus, it has become necessary to investigate other possible therapies. In this study, we examined the effects of native and oxidized forms of the sodium salts of eicosapentaenoic, docosahexaenoic, and arachidonic acids on T. vaginalis activity. Eicosapentaenoic acid was the most toxic with 190 and 380 μM causing approximately 90% cell death in Casu2 and ATCC 50142 strains, respectively. In contrast, oxidized eicosapentaenoic acid was the least toxic, requiring > 3 mM to inhibit activity, while low levels (10 μM) were associated with increased parasite density. Mass spectrometric analysis of oxidized eicosapentaenoic acid revealed C20 products containing one to six additional oxygen atoms and various degrees of bond saturation. These results indicate that eicosapentaenoic acid has different effects on T. vaginalis survival, depending on whether it is present in the native or oxidized form. A better understanding of lipid metabolism in T. vaginalis may facilitate the design of synthetic fatty acids that are effective for the treatment of metronidazole-resistant T. vaginalis.

Blood-Stage Parasitaemia and Age Determine Plasmodium falciparum and P. vivax Gametocytaemia in Papua New Guinea

A better understanding of human-to-mosquito transmission is crucial to control malaria. In order to assess factors associated with gametocyte carriage, 2083 samples were collected in a cross-sectional survey in Papua New Guinea. Plasmodium species were detected by light microscopy and qPCR and gametocytes by detection of pfs25 and pvs25 mRNA transcripts by reverse-transcriptase PCR (qRT-PCR). The parasite prevalence by PCR was 18.5% for Plasmodium falciparum and 13.0% for P. vivax. 52.5% of all infections were submicroscopic. Gametocytes were detected in 60% of P. falciparum-positive and 51% of P. vivax-positive samples. Each 10-fold increase in parasite density led to a 1.8-fold and 3.3-fold increase in the odds of carrying P. falciparum and P. vivax gametocytes. Thus the proportion of gametocyte positive and gametocyte densities was highest in young children carrying high asexual parasite densities and in symptomatic individuals. Dilution series of gametocytes allowed absolute quantification of gametocyte densities by qRT-PCR and showed that pvs25 expression is 10-20 fold lower than pfs25 expression. Between 2006 and 2010 parasite prevalence in the study site has decreased by half. 90% of the remaining infections were asymptomatic and likely constitute an important reservoir of transmission. However, mean gametocyte densities were low (approx. 1-2 gametocyte/μL) and it remains to be determined to what extent low-density gametocyte positive individuals are infective to mosquitos.

The A581G Mutation in the Gene Encoding Plasmodium falciparum Dihydropteroate Synthetase Reduces the Effectiveness of Sulfadoxine-Pyrimethamine Preventive Therapy in Malawian Pregnant Women.

The A581 G: mutation in the gene encoding Plasmodium falciparum dihydropteroate synthase (dhps), in combination with the quintuple mutant involving mutations in both dhps and the gene encoding dihydrofolate reductase (dhfr), the so-called sextuple mutant, has been associated with increased placental inflammation and decreased infant birth weight among women receiving intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP) during pregnancy. Between 2009 and 2011, delivering women without human immunodeficiency virus infection were enrolled in an observational study of IPTp-SP effectiveness in Malawi. Parasites were detected by polymerase chain reaction (PCR); positive samples were sequenced to genotype the dhfr and dhps loci. The presence of K540 E: in dhps was used as a marker for the quintuple mutant. Samples from 1809 women were analyzed by PCR; 220 (12%) were positive for P. falciparum. A total of 202 specimens were genotyped at codon 581 of dhps; 17 (8.4%) harbored the sextuple mutant. The sextuple mutant was associated with higher risks of patent infection in peripheral blood (adjusted prevalence ratio [aPR], 2.76; 95% confidence interval [CI], 1.82-4.18) and placental blood (aPR 3.28; 95% CI, 1.88-5.78) and higher parasite densities. Recent SP use was not associated with increased parasite densities or placental pathology overall and among women with parasites carrying dhps A581 G: . IPTp-SP failed to inhibit parasite growth but did not exacerbate pathology among women infected with sextuple-mutant parasites. New interventions to prevent malaria during pregnancy are needed urgently.

The Pattern of Parasite Density, Plasma Total Bile Acids and Lactate Dehydrogenase in Plasmodium Infected Patients in Rural Community

<b>Background to the study: </b>Pathophysiology of Plasmodium (vivax, ovale, falciparum and malariae) infection involves liver. Liver dysfunction and destruction of tissues could be indicated by the plasma level of Total Bile Acid (TBA) and Lactate Dehydrogenase (LDH). <b>Aim and Objective:</b> This work was designed to evaluate the pattern of parasite density, plasma total bile acids, and Lactate dehydrogenase in Plasmodium infected patients in rural community. <b>Materials and Methods:</b> The study was carried out in Kishi, the Headquarter of Irepo Local government area of Oyo state - Nigeria. Seven hundred and nine (709) subjects (Female: n=403: male: n=306) aged 5 to 68 years were tested for Plasmodium infection using Giemsa- thick film technique. The overall prevalence of Plasmodium infection among the seven hundred and nine subjects screened was found to be 29.1% (206) including 12.97% (92) HIV, HBsAg and anti-HCV seronagative patients and 16.1% (114) HIV, HBsAg or anti-HCV seropositive patients. Ninety two (92 (12.97%)) that were HIV, HBsAg and anti-HCV seronagative(female-58 (63.0%); male-34 (37%)) were recruited out of 206 (29.1%) that were found to be infected with plasmodium spp for the study. None of the subject was jaundiced as at the time of sample collection. Hepatitis B surface antigen (HBsAg) and anti-HCV tests were carried out by Enzyme Linked Immunozorbent Assay (ELIZA). HIV screening and confirmation were carried out by immuno-chromatographic and Immunobloting (Western blot) assays respectively. Fasting Plasma Total Bile Acids (TBA) and Lactate Dehydrogenase (LDH) were analyzed in the patients biochemically by spectrophotometry. <b>Result:</b> The result obtained showed an overall prevalence of Plasmodium infection as 29.1% (206) (female: 107 (52%); male: 99 (48%)) including 12.97% (92) (Female: 58 (63.0%) Male: 34 (37%)) that were HIV, HBsAg and anti-HCV seronagative and 16.1% (114) (Female: 61 (53.5%); Male: 53 (46.5%)) were co-infected with at least one of HIV, HBV or HCV. The plasmodium infected subjects were grouped into three based on the parasite density such as: patients with parasite density of 50-499; 500-999 and ≥1000. The mean value of the parasite density of each group was correlated with the plasma level of LDH and TBA. In all groups there was a strong positive correlation(R=1; R2 =1) between the plasma TBA, LDH and plasmodium parasite density. The pattern of parasite density obtained in the rural community studied include 45.7% had a mean parasite density of 282±12.0; 43.5% (853±31.0) and 10.9% (1130±61.0). There was also a statistical significant increase in the mean value of LDH and TBA with increase in parasite density with p<0.05. <b>Conclusion:</b> This work showed an overall prevalence of 29.1% (206) plasmodium infection including 16.1% (114) of the patients co-infected with at least one of HIV, HBV or HCV. The plasma level of LDH and TBA was also found to be positively correlated and directly proportional to the parasite density. Evaluation of these parameters is therefore recommended for effective control and management.

Influence of Clinical Status and Parasite Load on Erythropoiesis and Leucopoiesis in Dogs Naturally Infected with Leishmania (Leishmania) chagasi

BackgroundThe bone marrow is considered to be an important storage of parasites in Leishmania-infected dogs, although little is known about cellular genesis in this organ during canine visceral leishmaniasis (CVL).Methodology/Principal FindingsThe aim of the present study was to evaluate changes in erythropoiesis and leucopoiesis in bone marrow aspirates from dogs naturally infected with Leishmania chagasi and presenting different clinical statuses and bone marrow parasite densities. The evolution of CVL from asymptomatic to symptomatic status was accompanied by increasing parasite density in the bone marrow. The impact of bone marrow parasite density on cellularity was similar in dogs at different clinical stages, with animals in the high parasite density group. Erythroid and eosinophilic hypoplasia, proliferation of neutrophilic precursor cells and significant increases in lymphocytes and plasma cell numbers were the major alterations observed. Differential bone marrow cell counts revealed increases in the myeloid:erythroid ratio associated to increased numbers of granulopoietic cells in the different clinical groups compared with non-infected dogs.ConclusionsAnalysis of the data obtained indicated that the assessment of bone marrow constitutes an additional and useful tool by which to elaborate a prognosis for CVL.

HIV and Placental Infection Modulate the Appearance of Drug-Resistant Plasmodium falciparum in Pregnant Women who Receive Intermittent Preventive Treatment

Factors involved in the development of resistance to sulphadoxine-pyrimethamine (SP) by Plasmodium falciparum, particularly in the context of intermittent preventive treatment during pregnancy (IPTp), are not well known. We aimed to determine the impact of IPTp and human immunodeficiency virus (HIV) infection on molecular markers of SP resistance and the clinical relevance of resistant infections. SP resistance alleles were determined in peripheral (n = 125) and placental (n = 145) P. falciparum isolates obtained from pregnant women enrolled in a randomized, placebo-controlled trial of IPTp in Manhiça, Mozambique. Prevalence of quintuple mutant infections was 12% (23 of 185 isolates) in pregnant women who received placebo and 24% (20 of 85 isolates) in those who received SP (P = .031). When the last IPTp dose was administered at late pregnancy, mutant infections at delivery were more prevalent in placental samples (7 [23%] of 30, samples) than in peripheral blood samples (2 [7%] of 30 samples; P = .025), more prevalent in women who received IPTp-SP than in those who received placebo (odds ratio [OR], 8.13; 95% confidence interval [CI], 1.69-39.08), and more prevalent in HIV-positive women than in HIV-negative women (OR, 5.17; 95% CI, 1.23-21.66). No association was found between mutant infections and increased parasite density or malaria-related morbidity in mothers and children. IPTp with SP increases the prevalence of resistance markers in the placenta and in HIV-infected women at delivery, which suggests that host immunity is key for the clearance of drug-resistant infections. However, this effect of IPTp is limited to the period when blood levels of SP are likely to be significant and does not translate into more-severe infections or adverse clinical outcomes.