Plasma fatty acid abnormality in Sudanese drug-resistant epileptic patients.

Intervention studies have demonstrated that the n-3 fatty acids, docosahexaenoic and eicosapentaenoic acids, ameliorate seizure frequency in patients with drug-resistant epilepsy (DRE). There is a scarcity of fatty acid status of patients with epilepsy. We have investigated blood fatty acids of patients with DRE and assessed the indices of elongase and desaturase activities. DRE patients (n = 83) and healthy controls (n = 31) were recruited form Soba University Hospital Neurology Referral Clinic and Ibn-Auf paediatric Teaching Hospital Neurology Referral Clinic, Khartoum, Sudan. Fatty acid composition of plasma total lipids, phosphatidylcholine and neutral lipids were analysed. The patients compared with their healthy counterparts had higher levels of C14:0, C16:0, C18:0, C20:0, C22:0 (p<0.05) and C24:0, and total saturates (p<0.05). Similarly, the proportions of C16:1n-7, 18:1n-7, C18:1n-9, C20:1n-9, C24:1n-9 and total monounsaturated fatty acids; p<0.005) were higher in the drug-resistant patients. Conversely, the patients had lower levels of n-6 (C18:2n-6, C18:3n-6, C20:4n-6, n-6 metabolites and total n-6; p<0.005 and C20:2n-6 and C20:3n-6; p<0.05) and n-3 (C20:5n-3, C22:5n-3, C22:6n-3, ∑EPA and DHA, n-3 metabolites and total n-3; p<0.05) fatty acids. Indices of elongase and desaturase activities - The plasma total lipid ratios of C16:0/C14:0 (p = 0.001), C18:0/C16:0 (p = 0.001), C16:1n-7/C16:0 (p = 0.027), C18:1n-9/C18:0 (p = 0.022) and C22:4n-6/C20:4n-6 (p = 0.008) were higher and C18:3n-6/C18:2n-6 (p = 0.05), C20:4n-6/C20:3n-6 (p = 0.032) and C20:4n-6/C18:2n-6 (p>0.05) lower in the patients with drug-resistant epilepsy than in the healthy control subjects. DRE is associated with blood fatty acid perturbation and abnormal activities of long-chain fatty acid elongase (ELOVL-6), stearoyl-coenzyme A desaturase-1 (SCD-1), delta 6-fatty acid desaturase (D6D) and delta 5 fatty acid desaturase (D5D). N-3 fatty acids are known to ameliorate seizures frequency and dampen neuronal hyperexcitability. Therefore, patients with DRE should be regularly monitored and, if necessary, supplemented with n-3 fatty acids.

Dimethyl acetals, an indirect marker of the endogenous antioxidant plasmalogen level, are reduced in blood lipids of Sudanese pre-eclamptic subjects whose background diet is high in carbohydrate.

In Sudanese women with (n = 60) and without (n = 65) pre-eclampsia, circulating lipids, plasma and red cell saturated and monounsaturated fatty (MUFA) acids and dimethyl acetals (DMAs) were investigated. DMAs are an indirect marker of levels of plasmalogens, endogenous antioxidants, which play a critical role in oxidative protection, and cholesterol homeostasis. The pre-eclamptics had higher C18:1n-9 (p < 0.001) and ΣMUFA (p < 0.01) in plasma free fatty acids, C16:1n-7, C18:1n-9, ΣMUFA; 16:0/16:1n-7 (p < 0.01) in erythrocyte choline phosphoglycerides (ePC) and 16:1n-7, 18:1n-7 and 16:0/16:1n-7 (p < 0.01) in erythrocyte ethanolamine phosphoglycerides (ePE). In contrast, the DMAs 18:0, 18:1 and ΣDMAs in ePE, and 16:0, 18:0 and ΣDMAs in ePC were reduced (p < 0.001) in the pre-eclamptic women. This study of pregnant women with high carbohydrate and low fat background diet suggests pre-eclampsia is associated with oxidative stress and enhanced activity of the microsomal enzyme stearyl-CoA desaturase (delta 9 desaturase), as assessed by palmitic/palmitoleic (C16:0/C16:n-1) and stearic/oleic (C18/C18:1n-9) ratios.

Hydroxyurea therapy mobilises arachidonic Acid from inner cell membrane aminophospholipids in patients with homozygous sickle cell disease.

The cytotoxic compound hydroxyurea (HU) is effective therapy for sickle cell disease. However, its effect on unsaturated membrane lipids is unknown. Red cell fatty acids were investigated in HU-treated (n = 19) and HU-untreated (n = 17) sickle cell patients and controls (n = 20). The HU-treated compared with the HU-untreated patients had lower arachidonic (AA) acid level in ethanolamine, physphoglycerids (EPG) (22.9 ± 1.2 versus 24.0 ± 1.1%, P < 0.05) serine SPG (22.13 ± 2.2 versus 24.9 ± 2.3%, P < 0.01) phosphoglycerides. The treated patients and controls had comparable levels of docosahexaenoic (DHA) and total n-3 fatty acids in EPG and choline phosphoglycerides (CPG). In contrast, the untreated group had significantly (P < 0.05) lower DHA and total n-3 compared with the controls in EPG (2.7 ± 0.4 versus 3.2 ± 0.6% and 4.6 ± 0.5 versus 5.2 ± 0.7%) and CPG (0.7 ± 0.2 versus 1.0 ± 0.2% and 1.2 ± 0.2 versus 1.4 ± 0.3). HU is known to activate cytosolic phospholipase A2 and cyclooxygenase 2, and from this study, it appears to induce mobilisation of AA from the inner cell membrane EPG and SPG. Hence, eicosanoids generated from the released AA may play a role in clinical improvements which occur in HU-treated patients.

Cortisol and uncomplicated Plasmodium falciparum malaria in an area of unstable malaria transmission in eastern Sudan.

OBJECTIVE: To investigate the levels of serum cortisol in patients with uncomplicated Plasmodium falciparum (P. falciparum) malaria in an area of unstable malaria transmission in eastern Sudan. METHODS: The concentrations of cortisol were measured in sera of 25 patients with uncomplicated P. falciparum malaria (at presentation, 24 h and 7 d later) and 25 healthy volunteers using radioimmunoassay gamma counter. RESULTS: There was no significant difference in mean (SD) of total cortisol levels in patients with malaria in comparison with the control group; 602.2 (369.6) vs. 449.2(311.7) ng/mL, P=0.12. In patients with uncomplicated P. falciparum malaria, the mean (SD) presenting cortisol levels were significantly higher in comparison to the levels on day 7; 602.2 (369.6) vs. 373.6(139.1) ng/mL, P=0.009. In the patients with uncomplicated P. falciparum malaria (on presentation) cortisol levels were not correlated with initial temperature or the presenting parasitaemia. CONCLUSIONS: Thus, cortisol levels were not significantly different between the patients and the controls.

Milk of northern Sudanese mothers whose traditional diet is high in carbohydrate contains low docosahexaenoic acid.

AIM: The suckling neonates and infants are reliant primarily on the mother for optimal supply of docosahexaenoic acid (DHA). The richest source of preformed DHA is cold-water oily fish. Although there is paucity of data, existing evidence suggest women with restricted access to these foods have low or marginal DHA status. The aim of the study was to investigate milk fatty acids of Sudanese mothers whose traditional diet is high in carbohydrate and low in fat and gain some insight into the provision of DHA to the suckling offspring. METHODS: Colostrum (n =26), transitional (n=20) and mature (n=14) milk samples were obtained from Northern Sudanese women (NSW) recruited prior to delivery from Ibrahim Malik and Khartoum Teaching Hospitals. RESULTS: The arachidonic acid content of the colostrum (0.87±0.28%) and transitional (0.89± 0.29%) and mature (0.48±0.12%) milk of the NSW were broadly comparable with published international values. In contrast, the DHA level (colostrum 0.13±0.07%, transitional 0.13±0.06% and mature milk 0.06±0.05%) was very low. CONCLUSION: The study reveals breast milk of NSW, whose traditional diet is almost devoid of fish and fish products, is unlikely to provide sufficient DHA to support optimal postnatal neuro-visual development.

Erythrocyte antioxidant enzymes and plasma antioxidant vitamins in Sudanese women with pre-eclampsia.

This case-control study was conducted in Khartoum hospital, Sudan to investigate the levels of antioxidant enzymes (glutathione peroxidase, catalase and superoxide dismutase) in erythrocytes and plasma antioxidant vitamins (retinol and alpha-tocopherol) in Sudanese women with pre-eclampsia (37), in comparison with well-matched pregnant controls women with normal pregnancy (38). Enzymes were measured using ELISA and vitamins were measured using HPLC. There were no significant differences in the levels of these three antioxidant enzymes in pre-eclamptic women compared with the controls. Women with mild pre-eclampsia (diastolic blood pressure, DBP < 110) have slightly higher levels of erythrocyte glutathione peroxidase, and lower levels of catalase and superoxide dismutase compared with women with severe pre-eclampsia (DBP > or = 110). A significantly negative correlation was observed between the levels of glutathione peroxidase and DBP, r = -0.371, p = 0.02. There was no significant correlation between catalase (r = -0.033, p = 0.840) or superoxide dismutase levels (r = 0.067, p = 0.6) and DBP. While retinol levels were not different, levels of alpha-tocopherol were significantly higher in women with pre-eclampsia than the control group, p = 0.026. The plasma levels of both vitamins were not statistically significantly different when women with mild and severe pre-eclampsia were compared.

Erythrocyte omega-3 and omega-6 fatty acids profile in Sudanese women with pre-eclampsia.

A case-control study was conducted in Khartoum hospital, Sudan to compare omega-3 and omega-6 fatty acids profile in three phospholipid fractions (phosphatidylethanolamine, phosphatidylcholine and sphingomyelin) using gas chromatography in erythrocytes from 65 pre-eclamptic women and well-matched 60 healthy control pregnant women, both in the third trimester of pregnancy. While levels of arachidonic acid (omega-6 fatty acid) was significantly higher in women with pre-eclampsia in the sphingomyelin fraction only, the levels of eicosapentaenoic and docosahexaenoic acid (omega-3 fatty acid) in the three phospholipids fractions were significantly higher in women with pre-eclampsia than in the control group. Both omega-3 and omega-6 fatty acids profiles were not significantly different between patients with mild (diastolic blood pressure (DBP) <110 mmHg) and severe (DBP > or = 110 mmHg) pre-eclampsia.

Cortisol, prolactin, cytokines and the susceptibility of pregnant Sudanese women to Plasmodium falciparum malaria.

Understanding the hormonal and cytokine interactions that underlie susceptibility to the disease should be helpful in elucidating the pathogenesis of malaria during pregnancy. The current study was conducted in the Wad Medani hospital, in an area of central Sudan that is characterised by unstable malarial transmission. Its aims were to investigate the roles and interactions of cortisol, prolactin, interferon-gamma (IFN-gamma), interleukin-4 (IL-4) and interleukin-10 (IL-10) in pregnant women with Plasmodium falciparum malaria. The 82 pregnant subjects who were enrolled either had uncomplicated, P. falciparum malaria (the 47 cases) or were apparently uninfected and healthy women (the 37 controls) who were similar to the cases in terms of their mean age, weight, gravidity, gestational age and haemoglobin concentration. Compared with the controls, the cases were found to have significantly higher serum concentrations of total cortisol and IL-10 and significantly lower levels of prolactin and IFN-gamma (but similar concentrations of IL-4). The hormone and cytokine concentrations measured in the infected primigravidae were similar to those recorded in the infected multigravidae. Among the cases, there was a significant positive correlation between serum cortisol and IL-10 (r=0.188; P=0.025) and significant negative correlations between prolactin and both IL-4 (r=-0.175; P=0.038) and IL-10 (r=-0.186; P=0.027) but no significant correlation between prolactin and cortisol. During pregnancy, immune responses appear to be influenced by P. falciparum infections, irrespective of parity. Cortisol, prolactin and some cytokines appear to be key mediators in the host response to P. ?falciparum infection, although further research on this subject is clearly needed.

Severe malaria in an unstable setting: clinical and laboratory correlates of cerebral malaria and severe malarial anemia and a paradigm for a simplified severity scoring.

An interpretation of historical, clinical, and laboratory data was made to identify the correlates of and the diversity between cerebral malaria (CM) and severe malarial anemia (SMA) in a setting of low, seasonal, and unstable malaria transmission in eastern Sudan. Hemoglobin (Hb), random blood glucose (RBG), and anti-MSP antibodies were measured. Results showed that SMA and CM were significantly different with regard to age, malaria history, fever duration, convulsions, and hepatosplenomegaly. The MSP Ab response was inversely correlated with the number of previous malaria episodes but not with fever duration in the current attack. The spleen size was significantly inversely correlated with Hb level while hepatomegaly was significantly associated with low RBG. Furthermore, two malaria patients presented with neuropsychiatric upset. Finally, the correlates of SMA and CM fit perfectly with an adopted severity numeric scoring.

High frequency of Plasmodium falciparum CICNI/SGEAA and CVIET haplotypes without association with resistance to sulfadoxine/pyrimethamine and chloroquine combination in the Daraweesh area, in Sudan.

Estimation of the prevalence of the molecular markers of sulfadoxine/pyrimethamine (SP) and chloroquine (CQ) resistance and validation of the association of mutations with resistance in different settings is needed for local policy guidance and for contributing to a global map for anti-malarial drug resistance. In this study, malaria patients treated with SP alone (60) and SP with CQ (194) had a total treatment failure (TF) of 35.4%, with no difference between the two arms. The polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA) method was used to identify polymorphisms in 15 loci in the dhfr, dhps and pfcrt genes in a subset of 168 infections. The results revealed a similar frequency of all single nucleotide polymorphisms (SNPs) in the two arms, except dhps 581G, which was over-represented in infections that failed to respond to SP alone (TF). In all infections, a high frequency of dhfr CICNI haplotype (51I and 108N) was found, but without discrimination between the adequate clinical and parasitological response (ACPR, 75.6%) and TF (82.9%). Similarly, the dhps SGEAA haplotype (437G and 540E) (ACPR, 60.5%; TF, 65.9%) and the combined CICNI/SGEAA haplotype (ACPR, 50%; TF 55%) were not associated with TF. In contrast to other studies in Africa, the triple 51I/59R/108N mutation was rare (0.6%). In addition, the pfcrt CVIET haplotype (93%) was found to be associated with the CICNI/SGEAA haplotype. Finally, these data represent a baseline for SP resistance molecular markers needed before the deployment of SP/artesunate combination therapy in the Sudan.

Climatic variables and transmission of falciparum malaria in New Halfa, eastern Sudan.

The study investigated the role of climatic variables and irrigated agricultural on the seasonality of malaria transmission in New Halfa, eastern Sudan. A time-series analysis was performed using monthly climatic variables, monthly water available for irrigation of crops and monthly slide positive rate of malaria during the period 1986-2002. Cases of malaria were reported every month of the year with a mean of 13.0/100 persons/month (95% CI: 11.9-14.2), and bimodal annual pattern in autumn and winter seasons. Rainfall was the significant climatic variable in the transmission of the disease, whereas heavy rainfall was found to initiate epidemics. Temperature, relative humidity and irrigation water were not significant factors.

Identification of four new HLA-Cw alleles in the Sudanese population.

The major histocompatibility complex (MHC) is the most polymorphic region of the human genome. Human leukocyte antigen-C (HLA-C) genes are located in the class I region of MHC. Most polymorphisms of HLA class I antigens are present in exons 2 and 3, which encode the alpha1 and alpha2 domains of the HLA-A heavy chain, involved in both peptide binding and HLA-restricted recognition by the T-cell receptor. Four new HLA-Cw alleles were identified in the Sudanese population during HLA class I and class II sequencing-based typing at the HLA-C locus of case-control study of Sudanese HIV patients, in individuals from different ethnic background. Based on the localization of the affected amino acid positions in an outer loop of the alpha-helix forming the side of the peptide-binding groove, we do not expect the replacement mutations to have an effect on peptide binding or T-cell receptor interaction.

Pharmacokinetics of quinine and its metabolites in pregnant Sudanese women with uncomplicated Plasmodium falciparum malaria.

OBJECTIVES: The study was conducted in New Halfa teaching hospital, eastern Sudan to investigate the pharmacokinetics of quinine in pregnant Sudanese women. METHODS: Sixteen (eight pregnant and eight non-pregnant) Sudanese women infected with Plasmodium falciparum malaria were given a single dose of quinine hydrochloride (10 mg/kg body weight) as intravenous infusion over 2 h. The women were treated with intramuscular artemether. Plasma was collected before quinine administration and up to 72 h thereafter. These were analysed for quinine and its metabolites, 3-hydroxyquinine, (10R)-10,11-dihydroxyquinine and (10S)-10,11-dihydroxyquinine using high-performance liquid chromatography. RESULTS: The two groups were well matched in their basic characteristics. There was no significant difference in the mean maximum plasma concentration attained (C(max)), the mean time at which C(max) was attained, the elimination half-life (t(1/2)) and the total area under the plasma concentration vs. time curve (AUC) of quinine and its metabolites between the pregnant in non-pregnant women. CONCLUSION: There was no significant difference in quinine metabolism between pregnant and non-pregnant women and there is no need to adjust quinine dose when treating pregnant women.

Determinants of variant surface antigen antibody response in severe Plasmodium falciparum malaria in an area of low and unstable malaria transmission.

The variant surface antigens (VSA) of infected erythrocytes are important pathogenic markers, a set of variants (VSA(SM)), were assumed to be associated with severe malaria (SM), while SM constitutes clinically diverse forms, such as, severe malarial anemia (SMA) and cerebral malaria (CM). This study was conducted in Eastern Sudan, an area of seasonal and unstable malaria transmission. Parasites and plasma were obtained from patients with different clinical grades of malaria, and flow cytometry was used for analysis of VSA antibody (Ab) response. We found that individuals recognized a broader range of isolates had a higher level of VSA Ab against the recognized isolates (correlation coefficient, 0.727, P<0.001). Unexpectedly, at the time of malaria diagnosis, plasma from patients with CM recognized a significantly larger number of isolates than did the plasma from patients with SMA (P<0.001). Parasites obtained from patients with SMA or from children were better recognized than isolates obtained from patients with uncomplicated malaria or from adults, P<0.001, P=0.021, respectively. Taken together, the above findings suggest that the limitations in the VSA immunoglobulin G repertoire were most probably contributing to the pathogenesis of SMA but not to that of CM.

A comparison of the efficacy of artesunate plus sulfadoxine-pyrimethamine with that of sulfadoxine-pyrimethamine alone, in the treatment of uncomplicated, Plasmodium falciparum malaria in eastern Sudan.

In an open, randomized, clinical trial, conducted in New Halfa, eastern Sudan, in September-October 2004, the efficacies and adverse effects of artesunate plus sulfadoxine-pyrimethamine (SP), in the treatment of uncomplicated, Plasmodium falciparum malaria, were compared with those of SP alone. Patients were randomized to receive either artesunate (4 mg/kg. day) on days 0-2 plus SP (25 mg sulfadoxine/kg) on day 0 or the SP alone, and then followed-up for 28 days. Sixty patients completed follow-up. Compared with the 30 given artesunate plus SP (ASP), the 30 given SP alone were much more likely to be febrile (30% v. 3.3%; P=0.006) and parasitaemic (50% v. 6.7%; P<00001) on day 1. By day 3, 16.7% of the patients given SP alone were still febrile and 6.7% of them were still parasitaemic, although all the patients given ASP were then afebrile (P=0.02) and aparasitaemic (P=0.1). Five (16.7%) of the patients treated with SP alone but none of those given ASP appeared to be treatment failures (P<0.05). Parasite genotyping revealed that four of the five apparent treatment failures were true recrudescences but the other represented a re-infection detected on day 28. The true frequencies of cure by day 28 were therefore 100% for ASP and 86.7% for SP alone (P=0.02). Adverse effects of treatment (nausea, itching and giddiness) were observed with similar frequencies in the two treatment arms (10.0% of the patients given ASP v. 13.3% of the patients given SP alone; P>0.05). The frequencies of gametocytaemia during follow-up were, however, much lower in the ASP arm than in the SP-only (0.0% v. 23.3%; P=0.005).Thus, although the problems posed by adverse effects were similar in the two treatment arms, ASP appeared markedly better, in terms of fever- and parasite-clearance times and the prevalence of post-treatment gametocytaemia, than SP alone.

Submicroscopic Plasmodium falciparum infections during pregnancy, in an area of Sudan with a low intensity of malaria transmission.

There are few published studies on the burden of malaria during pregnancy from areas of sub-Saharan Africa where the intensity of malarial transmission is low, and few on submicroscopic malarial infections in pregnant women. The present study was conducted in New Halfa, an area of low-intensity transmission in eastern Sudan, between August 2003 and July 2004. The main aims were to assess the prevalences of submicroscopic and multiple Plasmodium falciparum infections in pregnant women (using the P. falciparum merozoite surface protein-2 as a polymorphic marker in PCR-based assays) and to determine the effects of such infections on anaemia during pregnancy. Of the 142 pregnant women who were recruited, only 17 (11.9%) were found smear-positive for P. falciparum by microscopy. The results of the PCR-based assays revealed, however, that 40 (32%) of the 125 smear-negative women had submicroscopic P. falciparum infections. Blood samples from 32 (80%) of those with submicroscopic infections showed only the FC 27 allele (of merozoite surface protein-2), six (15%) showed only the ICI allele, and two (5%) showed both of these alleles. Although the age, parity, gestational age and haemoglobin concentrations of the women with submicroscopic P. falciparum infections were not significantly different from those of the women who were smear- and PCR-negative, such infections may have a significant impact on materno-foetal health.

Efficacies of mefloquine alone and of artesunate followed by mefloquine, for the treatment of uncomplicated, Plasmodium falciparum malaria in eastern Sudan.

In late 2003, the efficacies of mefloquine monotherapy and of an artesunate-mefloquine combination, for the oral treatment of uncomplicated, Plasmodium falciparum malaria, were investigated and compared in New Halfa, in eastern Sudan. Of the patients who completed the 28 days of follow-up, 40 were treated only with single-dose mefloquine (at a dose of 25 mg/kg), and 38 with artesunate (at 4 mg/kg. day) for 3 days followed by single-dose mefloquine (at 15 mg/kg), given on the third day. Compared with those given the combination, the patients given mefloquine alone were more likely to suffer nausea, vomiting and dizziness (25.0% v. 2.6%; P=0.005) and to be found gametocytaemic (12.5% v. 0%; P=0.02) after treatment, and more likely to be found febrile (i.e. with a temperature >37.5 degrees C) on day 2 (25.0% v. 2.6%; P=0.005), although no patients were found febrile on day 3. Six of the patients--three (7.5%) of those given mefloquine only and three (7.9%) of those given the combination (P>0.05)--appeared to be treatment failures. Parasite genotyping indicated, however, that, although five of these six patients had true recrudescences, one (who had been treated with the combination) had been re-infected during the follow-up. The true frequencies of cure were therefore 92.5% after mefloquine alone and 94.7% after the combination (P>0.05). Thus, although the treatments appeared equally effective in clearing parasitaemias, the combination was better at clearing gametocytaemias and was less likely to cause adverse side-effects. It remains unclear why mefloquine given alone was almost 10-fold more likely to trigger adverse effects than treatment with a combination that contained the same drug. This may be a reflection of the different mefloquine doses and, for the patients given the combination, of the use of artesunate before the mefloquine treatment.

Clinical pattern of severe Plasmodium falciparum malaria in Sudan in an area characterized by seasonal and unstable malaria transmission.

A hospital-based study was carried out in Gedarif town, eastern Sudan, an area of markedly unstable malaria transmission. Among the 2488 diagnosed malaria patients, 4.4% fulfilled the WHO criteria for severe malaria, and seven died of cerebral malaria. The predominant complication was severe malarial anemia (45.4%), followed by convulsions (21%), cerebral malaria (16. 4%) and hypotension (11.8%). Severe malaria was recognized in all age groups, but 44.5% of patients were aged 2 to 4 years. The mean ages of patients with severe anemia (5.6 years) and convulsions (5.9 years) were significantly lower than the mean ages of patients with cerebral malaria (14.1 years) or hypotension (35.2 years). Patients with convulsions and cerebral malaria had significantly higher mean parasite count (69972 and 56110 parasites/microL, respectively) than patients with severe anemia (24637 parasites/microL) or hypotension (13667 parasites/microL). The mean blood glucose level was higher in patients with cerebral malaria than in patients with anemia, and higher in patients who died than in patients who survived. In this setting, the clinico-epidemiological pattern of severe malaria varies considerably from that of hyperendemic regions in sub-Saharan Africa, and there is considerable variation between the individual complications of severe malaria.

Epidemiology of malaria in New Halfa, an irrigated area in eastern Sudan.

A prospective study investigated the epidemiology of malaria in an agricultural area in eastern Sudan from November 1999 to June 2000 (1 irrigation and 1 dry season). In monthly parasite surveys, 99/ 1539 blood films from 190 individuals were positive for malaria: 95% for Plasmodium falciparum, 3% P. vivax and 2% P. ovale. The slide positive rate (SPR) of malaria episodes ranged from 3.7% to 12.8% in different months of the survey, with a peak in January. There was no significant difference in SPR between irrigation and dry seasons (7.2% versus 5.1%). SPR differed significantly by age group and was highest in under 5-year-olds. However, there was no significant difference in SPR between males and females. Transmission and intensity of malaria in this area is perennial and moderate rather than low.