Moderate Parasitemia Research Articles

High-Sensitivity C-Reactive Protein: A Potential Ancillary Biomarker for Malaria Diagnosis and Morbidity.

Background Malaria remains an important cause of morbidity and mortality in Africa. Previous studies that assessed C-reactive protein (CRP) have centered on the conventional method. This study evaluated the usefulness of high-sensitivity CRP (hs-CRP) in malaria diagnosis and morbidity in a pediatric population in Ghana. Methodology A total of 267 subjects (100 microscopically proven nonmalarial parasitaemics as controls and 167 plasmodium parasitaemic subjects as cases), between the ages of 7 months and 18 years, were recruited for this case-control study. Blood samples were collected for malaria parasite density by microscopic examination; full blood count, electrolytes, and liver function tests using an automated analyzer; and hs-CRP levels by sandwich ELISA method. Results The median hs-CRP concentration was lowest in the control group and increased significantly from low to high parasitaemia. The median hs-CRP level was significantly higher in high malaria parasitaemia compared to moderate and low malaria parasitaemia. Increasing hs-CRP cutoff (3.12-4.64 mg/L) presented with increasing specificity (79.3-93.1%) and sensitivity (96.4%-97.4%), except for moderate parasitaemia where a decline in sensitivity (80.9%) was observed. However, hs-CRP had relatively lower PPV but high NPV at low parasitaemia while both the PPV and NPV were moderate in moderate parasitaemia. Conclusion hs-CRP yielded a high sensitivity, specificity, and accuracy for low, moderate, and high-grade malaria, respectively, and thus may serve as an effective supplementary diagnostic and prognostic biomarker for Plasmodium parasite infection. However, hs-CRP might not be readily useful yet for diagnostic purposes in hospitals due to the relatively low PPV and NPV for low and moderate parasitaemia and thus necessitates further studies in larger cohorts.

Strong linear correlation between parasite density and ABO-blood group among patients with malaria parasite infection

Background: Analysis of the dynamics of Plasmodium falciparum infection as it relates to the ABO blood group system could expand our understanding of malaria pathology and further global efforts in addressing the scourge of malaria disease. This study seeks to examine the association between malaria infection and parasite density in relation to the ABO blood group system.Methods: 298 patients (Age Mean±SD = 28.8±9.16) were selected at random and screened for malaria parasite infection and parasite density quantification using the thick blood film method. Pearson correlation analysis was used to determine relationship between parasite density and blood group.Results: 88 (29.5%) patients tested positive to malaria parasite infection. Patients with blood group O recorded the highest number of positive cases (56.81%) and the least was found among those with blood group AB (3.42%). 93.18% of patients that tested positive were rhesus positive while 6.82% were rhesus negative. 40.90% of patients with mild parasitaemia and 10.23% of patients with moderate parasitaemia were of blood group O+. Pearson correlation coefficient was strong, direct and linear (r = 0.9184; r2 = 0.8434).Conclusions: This study has shown that there is a strong correlation between parasite density per microliter of blood in relation to the ABO-blood group type of individuals diagnosed with malaria parasite infection.

Canine hepatozoonosis: an update

Canine hepatozoonosis is caused by two different Hepatozoon species, responsible for distinct clinical syndromes. Hepatozoonosis beyond the United States is caused by Hepatozoon canis, transmitted by the tick Rhipicephalus sanguineus, whereas North American hepatozoonosis is caused by H. americanum, transmitted by Amblyomma maculatum. The former appears to be well adapted to its canine host, causing mostly subclinical or a mild clinical disease. Anorexia, depression, lethargy, fever, lymphadenopathy and body-weight loss are the most common clinical manifestations, which may be precipitated by concurrent infectious diseases or drug-induced immunosuppression. H. canis infection is mosdy diagnosed by the detection of intraneutrophilic gamonts in Giemsa-stained blood smears. Occasionally, a high level parasitemia may be observed (100% of circulating neutrophils), though moderate parasitemia (1-5%) is more common. Imidocarb dipropionate, with or without doxycycline, usually leads in rapid clinical remission and elimination of parasitemia, although relapses are not uncommon. In marked contrast, H. americanum, a recendy emerged pathogen, apparendy poorly adapted to dogs, is responsible for a severe chronic debilitating and often fatal disease. Fever, generalized pain, muscle atrophy and reluctance to move are prominent clinical symptoms attributable mainly to severe pyogranulomatous myositis and periosteal proliferative lesions. Since parasitemia is rarely found in H. americanum infection, a solid diagnosis should be based on muscle histopathology and/or serology. The combination of trimethoprime-sulphadiazine, clindamycin and pyrimethamine (induction phase), followed by long-term administration of the anticoccidial decoquinate (maintenance phase), achieves clinical remission and prolongs survival time, although relapses may frequently occur.

PERIPHERAL PARASITAEMIA AND ITS ASSOCIATION WITH PLASMA CYTOKINES LEVELS IN MALARIA-INFECTED PREGNANT WOMEN IN ABA, ABIA STATE, NIGERIA.

Background:Cytokines in pregnant female may not be a normal phenomenon as malarial infection is often associated with strong CD4+ cell activation and up-regulation of pro-inflammatory cytokines. We investigated the relationship between peripheral parasitaemia and plasma levels of cytokines among malaria infected pregnant women in Aba, Abia State, Nigeria.Materials and Methods:A total of 206 non-HIV positive asymptomatic malaria parasitaemic (n=144) and non-parasitaemic (n=62) pregnant women were recruited for this study alongside 80 non-pregnant women who served as positive (n=40) and negative (n=40) controls. Blood samples were aseptically collected from each subject and tested for HIV and malaria parasites using standard methods. Also, plasma levels of cytokines were measured using Th1/Th2 human cytokine ELISA kits (Abcam, UK). Analysis of Variance and Student’s t-test were used for Comparison of groups while Pearson’s Correlation Coefficient was used for tests of association.Results:The results revealed a mean parasite density of 685.56±484.55 parasites/µl of blood. Malaria infected pregnant subjects showed significantly higher levels of IFN-γ, TNF-α, IL-4, IL-6 and IL-10 when compared with their non-infected counterparts (P< 0.05). The cytokines evaluated were higher in moderate parasitaemia than mild parasitaemia. Positive correlation existed between peripheral parasite density (PPD) and IL-4 (r= 0.24, P=0.004), PPD and IL-6 (r = 0.35, P = 0.001) as well as PPD and IL-10 (r = 0.29, P = 0.001).Conclusion:This study showed that increase in peripheral parasitaemia increased levels of some plasma cytokines (IL-4, IL-6 and IL-10) but not IFN-γ and TNF-α in the malaria infected pregnant women studied.

Parasitemia and its relation to blood indices and liver function among malarial patients

Objectives: Objective of the study is to observe effects of Parasitemia on blood indices and liver function among malarial patients. Material & Method: A total of 67 malarial patients attending the OPD were enrolled as test subjects. Venus blood was collected. Malarial parasite density was determined in various blood smears and analyzed for blood indices- Hb, PCV, total WBC, lymphocytes, neutrophils, platelets, AST, ALT, ALP, total and direct bilirubin . Result & Discussion: There were significant decreases in the mean values of the hemoglobin (Hb), packed cell volume (PCV), total leucocyte counts (t WBC), lymphocytes and platelets. Neutrophils were significantly higher in patients with falciparummalaria in comparison to healthy subjects. There were significant increases in the mean activity enzyme values of AST, ALT, ALP and serum total and directbilirubin. The present study reports a significant increase in neutrophil level of individuals infected with P falciparum as compared to healthy subjects. Conclusion: Haemoglobin, platelet count, lymphocyte level, total WBC and neutrophil level were seen associated with mild, moderate and severe parasitaemia infection. Acute falciparum malaria infection is associated with an increase in serum activity of aspartate and alanine aminotransferase and alkaline phosphatase thus indicating that the infection is associated with acute liver injury.

Possible role of PGD 2 in malaria infections

To preliminarily investigate the possible role of prostaglandin D2 (PGD2) in malaria infections. Blood and urinary samples (n=120 each) were collected from Thai patients with Plasmodium falciparum (P.falciparum) with moderate (n=26) and high (n=4) parasitemia, patients with Plasmodium vivax (P.vivax) (n=30), patients with fever associated with other infections (n=30), and healthy subjects (n=30). PGD2 concentrations in plasma and urinary samples of healthy subjects, patients with fever associated with other infections and patients with malaria were determined using Prostaglandin D2-MOX express EIA kit (Cayman Chemical, USA). The possible association between PGD2 and malaria infections is clearly demonstrated with PGD2 concentration in urine. The urinary PGD2 concentrations were relatively high (about 5-fold) in patients with P.falciparum with moderate parasitemia and P.vivax infections compared with other groups. Furthermore, the concentration in patients with P.falciparum with moderate parasitemia and P.vivax infection were significantly higher than that in healthy subjects and patients with fever associated with other infections. Urinary PGD2 concentrations may offer a more dependable and useful tool for predicting malaria severity. Confirmation is this preliminary finding is required with a larger sample size.

Evaluation of some haemostatic parameters in falciparum malaria and HIV co-infection

Background: Studies from sub-Saharan Africa where malaria is endemic have observed high incidences of malaria and HIV co-infection. It has long been accepted that malaria causes alterations in haemostatic parameters and that HIV is associated with a wide range of haematological changes. We assessed the effect of the overlap of these infections on routine haemostatic parameters.Method: The study involved 337 subjects grouped according to their HIV and malaria status: Group 1 ‘Asymptomatic HIV seropositive, Plasmodium falciparum positive’ (n = 61); Group 2 ‘Asymptomatic HIV seropositive, P. falciparum negative’ (n = 73); Group 3 ‘Symptomatic HIV seropositive, P. falciparum positive’ (n = 49); Group 4 ‘Symptomatic HIV positive P. falciparum negative’ (n = 56); Group 5 ‘Control HIV negative, P. falciparum positive’ (n = 52) and Group 6 ‘Control HIV negative, P. falciparum negative’ (n = 46). Blood samples were taken for HIV testing, diagnosis of falciparum malaria and malaria parasite density counts. Citrated samples were used within one hour of collection for prothrombin time (PT) and activated partial thromboplastin time (APTT). CD4+ T cell counts, platelet count and haematocrit (Hct) were also performed.Results: Our results demonstrate greater alterations in APTT, PT and platelet count with prolongation of APTT, PT and lower platelet counts in HIV and malaria co-infection. In spite of this, the co-infected subjects with mild to moderate parasitaemia did not show a bleeding tendency; however, the risk is higher in severe malaria.Conclusion: These results suggest that co-infected subjects with severe malaria have a higher risk of bleeding and would require greater monitoring.

Alteration of coagulation profile in malaria patients and its correlation with degree of parasitemia: a prospective study

Background: Malaria is a major health problem in many parts of India. Several factors have been attributed to increased morbidity and mortality in malaria with altered haematological and coagulation parameters playing an important role. This study was performed to find the correlation between the alteration of coagulation profile and degree of parasitemia. Methods: Fifty patients with Malaria confirmed by PS, or Antigen assay underwent detailed clinical history, thorough physical examination and investigated with routine investigations, haematological and coagulation parameters were recruited in the study. Results: Parasitemia was found out for each of the patients and were categorized into mild moderate and severe parasitemia. This was followed by monitoring the alteration of coagulation profile with respect to severity of parasitemia. 17 patients had increased prothrombin time and most of these patients were Plasmodium falciparum positive. Thrombocytopenia was observed in 58% of the patients. Increased PT has positive co-efficient of correlation to degree of parasitemia with an ‘r’ value of 0.65 which is significant. Conclusions: It was found that the number of patients with increased prothrombin time increased with increase in degree of parasitemia, that is, the number of patients with deranged PT in severe parasitemia was significantly more than those in moderate parasitemia and this in turn was more than those in mild parasitemia.

Parasitaemia and Its Relation to Hematological Parameters and Liver Function among Patients Malaria in Abs, Hajjah, Northwest Yemen.

Plasmodium falciparum malaria is the most common infection in Yemen. The present study aims to investigate changes in hematological and hepatic function indices of P. falciparum infected individuals. This study included 67 suspected falciparum malarial patients attended in clinics and rural Abs Hospital (Tehama, Hajjah), Yemen, from October 2013 to April 2014. The diagnosis of malaria was confirmed by thick and thin film with Giemsa staining of malaria parasite. Hematological parameters and serum levels of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and bilirubin (total and direct) as test indicators of liver function were studied. Patients with parasitaemia tended to have significantly lower hemoglobin, hematocrit, white blood cell count, lymphocytes, and platelets, compared with healthy normal subjects. Neutrophils levels were significantly higher in cases of falciparum malaria in comparison to healthy normal subjects. Serums AST, ALT, ALP, and bilirubin (total and direct) in falciparum malaria patients were significantly higher (p < 0.0001) than those of falciparum malaria of free individuals. Hematological and liver dysfunctions measured parameters were seen associated with moderate and severe parasitaemia infection. This study concludes that hematological and hepatic dysfunction parameters could be indicator of malaria in endemic regions.

Clinical profile of Plasmodium falciparum and Plasmodium vivax infections in low and unstable malaria transmission settings of Colombia.

BackgroundMalaria transmission in Latin America is generally hypoendemic and unstable, with Plasmodium vivax as the most prevalent species. However, only a few studies have been carried out in areas with low and unstable transmission, whereas the clinical profile of malaria has been broadly described in hyperendemic areas. The pattern of clinical manifestations and laboratory findings in low to moderate endemic areas of Colombia is reported here.MethodsA passive surveillance study was conducted between 2011 and 2013 involving 1,328 patients with Plasmodium falciparum, P. vivax or mixed malaria infections attending malaria points-of-care of four malaria endemic-areas with distinct transmission intensities and parasite distribution. Trained physicians recorded clinical symptoms and signs as well as socio-demographic characteristics of study participants. Haematological, biochemical and urine tests were performed at the time of diagnosis.ResultsOut of 1,328 cases, 673 (50.7%) were caused by P. vivax; 650 (48.9%) were due to P. falciparum; and five (0.4%) patients had mixed infections (P. falciparum/P. vivax). Most patients (92.5%) presented with uncomplicated malaria characterized by fever, chills, headache, sweating, myalgia/arthralgia and parasitaemia ≤ 20,000 parasites/μL. Fever, tachycardia, pallor and abdominal pain on palpation were more frequent in P. falciparum patients, whereas mild hepatomegaly and splenomegaly were mostly observed with P. vivax. Non-severe anaemia (Hb 7.0-10.9 g/dL) was observed in 20% of the subjects, whereas severe anaemia (Hb < 7.0 g/dL) was present in four patients. Half of the patients presented thrombocytopaenia regardless of parasite species. Leukopaenia, neutrophilia and monocytosis were frequently observed in patients infected with P. falciparum. Mild-to-moderate biochemical alterations were present in ~25% of the patients, particularly abnormal bilirubin in those with P. falciparum and abnormal transaminases in P. vivax malaria patients. Proteinuria was present in ~50% of the patients regardless of parasite species, whereas haemoglobinuria was more common in P. vivax infections. Only 7.5% of the cases were classified as clinically severe malaria, caused by both P. vivax and P. falciparum.ConclusionsThe high prevalence of uncomplicated malaria associated with moderate parasitaemia suggests the importance of timely diagnosis and effective treatment and encourages new activities to further decrease complicated malaria cases and mortality.

Effects of malaria parasite density on blood cell parameters.

Changes in blood cell parameters are already a well-known feature of malarial infections. To add to this information, the objective of this study was to investigate the varying effects that different levels of parasite density have on blood cell parameters. Patients diagnosed with malaria at Phobphra Hospital, Tak Province, Thailand between January 1st 2009 and January 1st 2012 were recruited as subjects for data collection. Blood cell parameters of 2,024 malaria-infected patients were evaluated and statistically analyzed. Neutrophil and platelet counts were significantly higher, however, RBC count was significantly lower in patients with P. falciparum infection compared to those with P. vivax infection (p<0.0001). Leukocyte counts were also significantly higher in patients with high parasitemia compared to those with low and moderate parasitemia. In terms of differential leukocyte count, neutrophil count was significantly higher in patients with high parasitemia compared to those with low and moderate parasitemia (p<0.0001). On the other hand, both lymphocyte and monocyte counts were significantly lower in patients with high parasitemia (p<0.0001). RBC count and Hb concentration, as well as platelet count were also significantly reduced (p<0.05) and (p<0.0001), respectively. To summarize, patients infected with different malaria parasites exhibited important distinctive hematological parameters, with neutrophil and eosinophil counts being the two hematological parameters most affected. In addition, patients infected with different malarial densities also exhibited important changes in leukocyte count, platelet count and hemoglobin concentration during the infection. These findings offer the opportunity to recognize and diagnose malaria related anemia, help support the treatment thereof, as well as relieve symptoms of severe malaria in endemic regions.

Molecular and biological characterization of Trypanosoma cruzi strains isolated from children from Jequitinhonha Valley, State of Minas Gerais, Brazil

The biological diversity of Trypanosoma cruzi strains plays an important role in the clinical and epidemiological features of Chagas disease. Eight T. cruzi strains isolated from children living in a Chagas disease vector-controlled area of Jequitinhonha Valley, State of Minas Gerais, Brazil, were genetically and biologically characterized. The characterizations demonstrated that all of the strains belonged to T. cruzi II, and showed high infectivity and a variable mean maximum peak of parasitemia. Six strains displayed low parasitemia, and two displayed moderate parasitemia. Later peaks of parasitemia and a predominance of intermediate and large trypomastigotes in all T. cruzi strains were observed. The mean pre-patent period was relatively short (4.2 ± 0.25 to 13.7 ± 3.08 days), whereas the patent period ranged from 3.3 ± 1.08 to 34.5 ± 3.52 days. Mortality was observed only in animals infected with strain 806 (62.5%). Histopathological analysis of the heart showed that strains 501 and 806 caused inflammation, but fibrosis was observed only in animals infected with strain 806. The results indicate the presence of an association between the biological behavior in mice and the genetic characteristics of the parasites. The study also confirmed general data from Brazil where T. cruzi II lineage is the most prevalent in the domiciliary cycle and generally has low virulence, with some strains capable of inducing inflammatory processes and fibrosis.

Artemether and artesunate show the highest efficacies in rescuing mice with late-stage cerebral malaria and rapidly decrease leukocyte accumulation in the brain.

The murine model of cerebral malaria (ECM) caused by Plasmodium berghei ANKA (PbA) infection in susceptible mice has been extensively used for studies of pathogenesis and identification of potential targets for human CM therapeutics. However, the model has been seldom explored to evaluate adjunctive therapies for this malaria complication. A first step toward this goal is to define a treatment protocol with an effective antimalarial drug able to rescue mice presenting late-stage ECM. We evaluated the efficacy of artemisinin, artemether, artesunate, and quinine given intraperitoneally once a day, and combinations with mefloquine, in suppressing PbA infection in mice with moderate parasitemia. Artemether, artesunate, and quinine were then evaluated for efficacy in rescuing PbA-infected mice with ECM, strictly defined by using objective criteria based on the presentation of clinical signs of neurological involvement, degree of hypothermia, and performance in a set of six motor behavior tests. Artemether at 25 mg/kg presented the fastest parasite killing ability in 24 h and fully avoided recrudescence in a 5-day treatment protocol. Artemether and artesunate were equally effective in rescuing mice with late-stage ECM (46 and 43% survival, respectively), whereas quinine had a poor performance (12.5% survival). Artemether caused a marked decrease in brain leukocyte accumulation 24 h after the first dose. In conclusion, artemether and artesunate are effective in rescuing mice with late-stage ECM and decrease brain inflammation. In addition, the described protocols for more strict clinical evaluation and for rescue treatment provide a framework for studies of CM adjunctive therapies using this mouse model.

NÍVEIS DE IMUNOGLOBULINAS EM RATOS INFECTADOS POR Trypanosoma evansi

This study aimed at evaluating the immunoglobulin levels in rats experimentally infected with Trypanosoma evansi. Twenty animals were inoculated with 106 trypomastigote forms and ten rats were used as control. Parasitemia was monitored by examining daily blood smears. Rats were separated into three equal groups in the fifth day PI: groups A and B were formed by rats with low and moderate parasitemia, respectively; group C was formed by non-infected rats. IgG and IgM were evaluated by ELISA test and were superior when compared to group C. The IgM levels did not differ between the infected groups. It may be concluded that the infected rats showed an immunological response against T. evansi, although this was not enough to eliminate the parasite in acute infection. KEY WORDS: IgG, IgM, Ratus norvergicus, Trypanosoma evansi.

Malaria parasitaemia among pregnant women in a rural community of eastern Nigeria; need for combined measures

Malaria in pregnancy is a major contributor to adverse maternal and perinatal outcome. In hyper endemic areas like ours, it is a common cause of anaemia in pregnancy in both immune and non-immune individuals and is aggravated by poor socioeconomic circumstances. The aim of this study is to assess the prevalence of asymptomatic malaria parasitaemia among pregnant women in a rural setting. 272 pregnant women, aged between 18 and 40 years in some remote rural areas of Ebonyi State, Nigeria were recruited between January 2007 and March 2008.Their blood samples were collected and examined for malaria parasite, haemoglobin and packed cell volume using standard methods. Our results showed 59.9% prevalence of parasitaemia with the highest prevalence occurring in the first trimester [84.1%]. Among the positive cases, mild parasitaemia was recorded in 47.2% moderate parasitaemia in 37.4% while severe parasitaemia was recorded in 15.3% of cases. These differences were statistically significant [P<0.016]. Furthermore the distribution of malaria densities in different gravidity groups showed an inverse relationship, 45.4% in primigravidae, [31.9%] in secundigravidae and [10.4%] among people with more than five pregnancies. These findings were statistically significant [P<0.0001]. The prevalence of anaemia in pregnancy in this study was 62.4%. Apart from the use of nets, drugs and vector control, the prevention of malaria in pregnancy in very poor socioeconomic settings should make provision for nutritional support.

Iron Status of Malaria Patients in Douala - Cameroon

2 Abstract: In Africa, anaemia associated with malaria infection is a major cause of childhood morbidity and mortality. Problem of severe anemia linked to malaria is increasing as antimalarial drugs resistant parasites are widespread throughout Africa. In Cameroon, malaria turns out to be the major disease with the higher number of annual deaths, especially among children under fives and pregnant women. To assess the iron status among malarial patients in Douala where malaria is endemic, 163 malarial subjects (aged 0 to 60 years) and 98 uninfected volunteer subjects (aged between 0 - 65 years) were screened for this study. Iron status was evaluated using three biochemical (Serum Iron: SI, Total Iron Binding Capacity: TIBC and Transferrin Saturation: TS) and five haematological (Haemoglobin: HGB, Haematocrit: HTC, Mean Cell Volume: MCV, Mean Cell Haemoglobin: MCH and Mean Corpuscular Haemoglobin Concentration: MCHC) parameters. It was observed that 41.7% and 63.20% of malaria patients were serum iron and haemoglobin deficient respectively. Moreover, the rates of SI, TS, HGB, HTC, MCV and MCH were significantly lower in malarial than controls (P<0.01). However, the TIBC rates were significantly higher among the malarial in comparison with the uninfected subjects (P<0.01). This rate decreased with age while HGB, HTC and MCV percentages increased with age. Parasitic density is higher in patients aged between 0 - 3 years than those between 4 - 25 years and between 26 - 60 years of age. We noticed significant (P<0.01) increase of SI with moderate parasitemia. Significant correlations (P<0.001) were observed among malarial. Malaria negatively affects iron status, but we need further research on iron metabolism for the better comprehension of th e mechanism by which Plasmodium falciparum interact with iron status.

Antiplasmodial Triterpenoids from Ekebergia capensis

From the stem bark of Ekebergia capensis, 10 new triterpenoid compounds, ekeberins A (1), B (2), C1 (3), C2 (4), C3 (5), D1 (6), D2 (7), D3 (8), D4 (9), and D5 (10), were isolated together with 17 known compounds. The structures of these new compounds were elucidated on the basis of the results of spectroscopic analysis, and the absolute configuration of compounds 6-10 were determined by partial synthesis from known compounds and using the Mosher ester method. Several of these compounds were screened in vitro against both chloroquine (CQ)-sensitive and -resistant Plasmodium falciparum isolates and were found to exhibit moderate antiplasmodial activity, with compounds 20 (7-deacetoxy-7-oxogedunin) and 27 (2-hydroxymethyl-2,3,22,23-tetrahydroxy-2,6,10,15,19,23-hexamethyl-6,10,14,18-tetracosatetraene) showing IC50 values of 6 and 7 microM, respectively. Compound 27 at a dose of 500 mg/kg showed moderate parasitemia suppression of 52.9% against P. berghei NK 65 in a mouse model.

DISSEMINATED INTRAVASCULAR COAGULATION COMPLICATED BY PERIPHERAL GANGRENE IN A RHESUS MACAQUE (MACACA MULATTA) EXPERIMENTALLY INFECTED WITH PLASMODIUM COATNEYI

We report the first case of disseminated intravascular coagulation (DIC) complicated by peripheral gangrene induced by Plasmodium coatneyi in rhesus monkeys. Ten days after experimental challenge, numerous petechiae were noted over the trunk and extremities, with polychromasia, severe anemia, thrombocytopenia, and moderate parasitemia. These changes were accompanied by elevated serum activity of blood urea nitrogen, creatinine, transaminases, and creatinine phosphokinase. The animal received intravenous fluid support, artemether, and blood transfusion. Three days after treatment, the platelet counts returned to normal, and parasitemia was abated. However, several areas of skin discoloration with gangrenous tissue in the hands and the tail were observed. Coagulation profile showed elevated D-dimers and elevated levels of fibrinogen/fibrin degradation products with low levels of protein S functional activity. DIC with peripheral gangrene is very rare in Plasmodium-infected individuals. Our results indicate that the experimental model of P. coatneyi infection of rhesus monkeys is important for studies of malarial anemia and coagulopathy.

Evaluation of antioxidant status and oxidative stress in cattle naturally infected with Theileria annulata

To assess the antioxidant status and oxidative stress in bovine theileriosis due to Theileria annulata blood samples were collected from 35 clinically affected cattle referred to Veterinary Teaching Hospital, School of Veterinary Medicine, Urmia University, Urmia, Iran. Complete blood count, piroplasm parasitemia percentage, erythrocyte glutathione peroxidase, superoxide dismutase, catalase and glucose-6-phosphate dehydrogenase activities, malondialdehyde concentration, osmotic fragility test and median corpuscular fragility were determined and the results were compared with those of 50 healthy controls. Of 35 affected cattle, 12 (34.28%) had severe anemia and 23 had mild to moderate anemia and parasitemia varied from 5 to 40%. The activities of erythrocyte glutathione peroxidase, superoxide dismutase and glucose-6-phosphate dehydrogenase were significantly lower ( P < 0.0001) and the activity of catalase was significantly higher in the affected cattle than in healthy ones ( P < 0.001). Malondialdehyde concentration in erythrocytes of affected cattle was significantly more than those of healthy cattle ( P < 0.001). The affected cattle showed increased fragility of erythrocytes, so that median corpuscular fragility (MCF) in affected group was significantly lower than those of healthy group ( P < 0.0001). Median corpuscular fragility showed a positive correlation with the severity of parasitemia ( r = 0.81, P < 0.0005) and a negative correlation with the activities of GSH-Px ( r = −0.78, P < 0.0001), SOD ( r = −0.71, P < 0.0005), catalase ( r = −0.53, P < 0.018) and G6PD ( r = −0.58, P < 0.0005). The results of this study suggest that oxidative damage to RBCs may contribute to the pathogenesis of anemia in bovine theileriosis.

English

This study was undertaken to establish data on the roles of lipid peroxidation and ascorbic acid in the pathology of malaria in Nigeria children. We measured the levels of malondialdehyde (MDA), a marker of lipid peroxidation and ascorbic acid in the plasma of 406 parasitaemic and 212 non-parasitaemic Nigerian children. Lipid peroxidant levels were significantly higher in children with moderate and high parasitaemia (16.88 and 13.64 MDA µM/ml, respectively), than in non-parasitaemic controls (8.71 MDA µM/ml). Malaria infection resulted in significant reduction in ascorbic acid levels of children with moderate and high parasitaemia. The MDA and ascorbic acid levels of children with low parasitaemia were not significantly higher than the levels in non-parasitaemic controls. High levels of lipid peroxidation corresponded with low levels of ascorbic acid and this may be responsible for tissue damage associated with pathology of malaria in Nigerian children.