Association of genotype III of dengue virus serotype 3 with disease outbreak in Eastern Sudan, 2019.

BACKGROUND: Dengue fever (DF) is an arthropod-borne disease caused by dengue virus (DENV). DENV is a member of the genus Flavivirus in the family Flaviviridae. Recently, DENV has been reported as an important emerging infectious viral pathogen in Sudan. Multiple outbreaks and sporadic cases of DF have been frequently reported in the eastern region of Sudan. The present study was conducted to confirm DENV outbreak in Kassala State, eastern Sudan, 2019, and to provide some information on the molecular characterization of the DENV isolate associated with the disease outbreak. METHODS: A hundred serum samples were collected during the outbreak from residents of Kassala State, Sudan, 2019. ELISA was used to detect DENV non structural protein NS1 (DENV-NS1) in acute phase sera sampled during the disease outbreak. RT-PCR assays were used to amplify a fragment of the capsid/pre-membrane region (CprM) of the viral polyprotein gene. The PCR products of the amplified CprM region of the viral polyprotein gene were purified and partial sequences were generated and used to confirm the specificity of DENV sequences and to identify the virus serotype. Phylogenetic tree was constructed to determine the genotype of DENV associated with the outbreak. RESULTS: Using DENV-NS1 ELISA assay, DENV infection was confirmed in 23% sampled sera. The detection of DENV RNA was made possible using group-specific RT-PCR assay. The virus was serotyped as DENV serotype 3 (DENV-3) using DENV serotype-specific RT-PCR assay. Phylogenetic analysis of the partial CprM sequences of the viral polyprotein gene indicates that the virus belonged to genotype III of DENV-3. CONCLUSION: The scientific data presented in this investigation confirmed that genotype III of DENV-3 was associated with the disease outbreak in eastern Sudan, 2019. The study represents the first report on molecular characterization of DENV-3 in Sudan.

Case report of a novel homozygous splice site mutation in PLA2G6 gene causing infantile neuroaxonal dystrophy in a Sudanese family.

BACKGROUND: Infantile neuroaxonal dystrophy (INAD) is a rare hereditary neurological disorder caused by mutations in PLA2G6. The disease commonly affects children below 3 years of age and presents with delay in motor skills, optic atrophy and progressive spastic tetraparesis. Studies of INAD in Africa are extremely rare, and genetic studies from Sub Saharan Africa are almost non-existent. CASE PRESENTATION: Two Sudanese siblings presented, at ages 18 and 24 months, with regression in both motor milestones and speech development and hyper-reflexia. Brain MRI showed bilateral and symmetrical T2/FLAIR hyperintense signal changes in periventricular areas and basal ganglia and mild cerebellar atrophy. Whole exome sequencing with confirmatory Sanger sequencing were performed for the two patients and healthy family members. A novel variant (NM_003560.2 c.1427 + 2 T > C) acting on a splice donor site and predicted to lead to skipping of exon 10 was found in PLA2G6. It was found in a homozygous state in the two patients and homozygous reference or heterozygous in five healthy family members. CONCLUSION: This variant has one very strong (loss of function mutation) and three supporting evidences for its pathogenicity (segregation with the disease, multiple computational evidence and specific patients' phenotype). Therefore this variant can be currently annotated as "pathogenic". This is the first study to report mutations in PLA2G6 gene in patients from Sudan.

The differential effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on seizure frequency in patients with drug-resistant epilepsy - A randomized, double-blind, placebo-controlled trial.

OBJECTIVES: The omega-3 (n-3) fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are known to play an important role in maintenance and modulation of neuronal functions. There is evidence that omega-3 fatty acids may have anticonvulsant effects. The effect of DHA and EPA on seizure rate in patients with drug-resistant epilepsy (DRE) was investigated. METHODS: A double-blind, randomized, placebo-controlled clinical trial included ninety-nine (n = 99) subjects with DRE, aged 5-16 years (n = 85) and 17-45 years (n = 14). After randomization, subjects were given two, four, or six capsules per day of DHA (417.8 mg DHA and 50.8 mg EPA/capsule, n = 33), EPA (385.6 mg EPA and 81.2 mg DHA/capsule, n = 33), or placebo (high oleic acid sunflower oil, n = 33) for one year. The primary endpoint was the effect of treatment on rate of seizure. Random-effects negative binomial regression models were fitted to model the patients' total count of seizures per month. The treatment effects on seizure incidence rate ratio (IRR) were tested after controlling for the covariate effects of gender, age, rate of seizure per week at enrollment, type of seizure, and number of antiepileptic drug (AED) combinations used at enrollment. RESULTS: Fifty-nine subjects (n = 59) completed the study (59.6%). The average number of seizures per month were 9.7 ±â€¯1.2 in the EPA group, 11.7 ±â€¯1.5 in the DHA group, and 16.6 ±â€¯1.5 in the placebo group. Age, gender, and seizure-type adjusted seizure IRRs of the EPA and DHA groups compared with the placebo group were 0.61 (CI = 0.42-0.88, p = 0.008, 42% reduction) and 0.67 (CI = 0.46-1.0, p = 0.04, 39% reduction), respectively. There was no difference in IRR between the EPA and DHA groups (p = 0.56). Both treatment groups had a significantly higher number of seizure-free days compared with the placebo group (p < 0.05). SIGNIFICANCE: This study demonstrates that EPA and DHA are effective in reducing seizure frequency in patients with DRE.

Sickle cell disease in western Sudan: genetic epidemiology and predictors of knowledge attitude and practices.

OBJECTIVE: To investigate the epidemiology of sickle cell disease (SCD) and determinants of knowledge, attitudes and practices (KAP) towards SCD in western Kordofan State, Sudan. METHODS: A community-based, descriptive, cross-sectional study was conducted in three towns. Three hundred and seventy-two households were polled, and blood samples for haemoglobin phenotyping were collected from 1116 individuals. Sociodemographic, socio-economic and KAP data were collected using investigator-administered questionnaires. Descriptive, frequency distribution and multiple regression analyses were performed. RESULTS: About 50.9% of the study population were Misseriya tribes. Consanguineous marriages were reported by 67.5% of the households. The highest percentage of homozygous SCD was 2.8% among children under 5 years of age. About 24.9% were carriers of HbS allele (HbAS). HbS allele frequency was highest in children aged 5-11 years (18.3%, CI: 13.7-22.9%) and lowest in males >15 years old (12.0%, CI: 6.1-17.9%). The average HbS frequency across all age groups was 14.5% (95% CI: 12.2-16.8%). The most frequent ß-globin gene cluster haplotype was the Cameroon (30.8%), followed by the Benin (21.8%), the Senegal (12.8%) and the Bantu (2.2%) haplotypes. About 17.0% of all-cause child deaths were due to SCD. The estimated change in log odds of having the SS genotype per year increase in age was (-) 0.0058 (95% CI -0.0359, 0.0242). This represents a non-statistically significant 2.9% increase in 5-year mortality for individuals with the SS genotype relative to those with AS and AA genotypes. About 46.9% of the households had poor knowledge, 26.1% had satisfactory knowledge, and 26.9% had good knowledge about sickle cell disease. Mothers' and fathers' educational levels were significant predictors of good knowledge about SCD (P < 0.05). About 48.0% had a satisfactory attitude towards sickle cell disease while 30.7% had poor attitude and only 21.3 showed good attitudes. Poor knowledge about SCD and low socio-economic status were the strongest positive predictors of poor attitude and practices towards SCD (P < 0.01). CONCLUSIONS: Sickle cell disease is a major health problem in West Kordofan, Sudan. Knowledge, attitude and practices towards the disease are not satisfactory. The development of public health programs is highly recommended to control and manage SCD in western parts of Sudan.

Omega 3 (n-3) fatty acids down-regulate nuclear factor-kappa B (NF-κB) gene and blood cell adhesion molecule expression in patients with homozygous sickle cell disease.

Chronic inflammation and reduced blood levels of omega-3 fatty acids (n-3) are known characteristics of sickle cell disease (SCD).The anti-inflammatory properties of n-3 fatty acids are well recognized. Omega-3 treated (n = 24), hydroxyurea (HU) treated (n = 18), and n-3 untreated (n=21) homozygous SCD patients (HbSS) and healthy (HbAA) controls (n = 25) matched for age (5-16 years), gender and socioeconomic status were studied. According to age (5-10) or (11-16) years, two or three capsules containing 277.8 mg docosahexaenoic (DHA) and 39.0mg eicosapentaenoic (EPA) or high oleic acid placebo (41%) were assigned to n-3 treated and n-3 untreated groups, respectively. Hydroxyurea treated group was on dosage more than 20 mg/kg/day. The effect of supplementation on systemic and blood cell markers of inflammation was investigated. The n-3 treated group had higher levels of DHA and EPA (p < 0.001) and lower white blood cell count and monocyte integrin (p < 0.05) compared with the n-3 untreated. No difference was detected between the two groups regarding C-reactive protein, granulocytes integrin and selectin, plasma tumour necrosis factor-α and interleukin-10. The n-3 treated group had lowered nuclear factor-kappa B (NF-κB) gene expression compared to n-3 untreated and HU treated groups (p < 0.05). This study provides evidence that supplementation with n-3 fatty acids may ameliorate inflammation and blood cell adhesion in patients with SCD.

Rift Valley fever, Sudan, 2007 and 2010.

To elucidate whether Rift Valley fever virus (RVFV) diversity in Sudan resulted from multiple introductions or from acquired changes over time from 1 introduction event, we generated complete genome sequences from RVFV strains detected during the 2007 and 2010 outbreaks. Phylogenetic analyses of small, medium, and large RNA segment sequences indicated several genetic RVFV variants were circulating in Sudan, which all grouped into Kenya-1 or Kenya-2 sublineages from the 2006-2008 eastern Africa epizootic. Bayesian analysis of sequence differences estimated that diversity among the 2007 and 2010 Sudan RVFV variants shared a most recent common ancestor circa 1996. The data suggest multiple introductions of RVFV into Sudan as part of sweeping epizootics from eastern Africa. The sequences indicate recent movement of RVFV and support the need for surveillance to recognize when and where RVFV circulates between epidemics, which can make data from prediction tools easier to interpret and preventive measures easier to direct toward high-risk areas.

Association between Serum 25-Hydroxyvitamin D Concentrations and Academic Performance among Adolescent Schoolchildren: A Cross-Sectional Study.

The level of association between 25-hydroxyvitamin D (25[OH]D) levels and students' academic performance has not yet been established. The current study aimed to investigate the association between serum 25(OH)D levels and academic performance among schoolchildren in Sudan. A cross-sectional study was conducted among schoolchildren during the 2021/2022 academic year from four randomly selected schools in Almatamah, River Nile State, northern Sudan. Sociodemographic data were collected using a questionnaire. Anthropometric measurements were performed in accordance with standard procedures. Academic performance was obtained from school records. Serum 25(OH)D levels were measured, and regression (multiple linear regression and multivariate logistic) analyses were performed. A total of 241 participants were enrolled in this study, of whom 129 (53.5%) were female. The mean standard deviation (SD) of the participants' ages was 15 ± 1.6 years. In multiple linear regression tests, being female, age, employment, and serum 25(OH)D level were positively associated with academic performance. The average overall academic score was 33.74%. Of the 241 participants, 95 (39.4%) and 149 (61.6%) had good and poor academic performances, respectively. In multivariable logistic regressions, age and 25(OH)D level were inversely associated with poor academic performance and vitamin D deficiency was associated with poor performance. The current study revealed a positive association between 25(OH)D levels and adolescents' academic performance. Effective interventional programs are needed to maintain sufficient vitamin D levels during childhood and adolescence and, as a consequence, to improve academic performance.

Thrombocytopenia in pregnant women with Plasmodium falciparum malaria in an area of unstable malaria transmission in eastern Sudan.

BACKGROUND: Blood platelet levels are being evaluated as predictive and prognostic indicators of the severity of malaria infections in humans. However, there are few studies on platelets and Plasmodium falciparum malaria during pregnancy. METHODS: A case-control study was conducted at Gadarif Hospital in Eastern Sudan, an area characterized by unstable malaria transmission. The aim of the study was to investigate thrombocytopenia in pregnant women with P. falciparum malaria (cases) and healthy pregnant women (controls). RESULTS: The median (interquartile) platelet counts were significantly lower in patients with malaria (N = 60) than in the controls (N = 60), 61, 000 (43,000-85,000) vs. 249,000 (204,000-300,000)/µL, respectively, p < 0.001. However, there was no significant difference in the platelet counts in patients with severe P. falciparum malaria (N = 12) compared with those patients with uncomplicated P. falciparum malaria (N = 48), 68, 000 (33,000-88,000)/µL vs. 61, 000 (45,000-85,000)/µL, respectively, p = 0.8. While none of the control group had thrombocytopenia (platelet count <75, 000/µL), it was found that 6/12 (50%) and 27/48 (56.2%) (p <0.001) of the patients with severe malaria and uncomplicated malaria had thrombocytopenia, respectively. Pregnant women with P. falciparum malaria, compared with the pregnant healthy control group, were at higher risk (OR = 10.1, 95% CI = 4.1-25.18; p < 0.001) of thrombocytopenia. Two patients experienced bleeding, and there was one maternal death due to cerebral malaria where the patient's platelet count was only 28,000/µL. CONCLUSION: P. falciparum malaria is associated with thrombocytopenia in pregnant women in this setting. More research is needed.

A nosocomial transmission of crimean-congo hemorrhagic fever to an attending physician in North Kordufan, Sudan.

BACKGROUND: Crimean-Congo hemorrhagic fever (CCHF), a tick-borne disease caused by Crimean-Congo hemorrhagic fever virus (CCHFV), is a member of the genus Nairovirus in the family Bunyaviridae. Recently, CCHFV has been reported as an important emerging infectious viral pathogen in Sudan. Sporadic cases and multiple CCHF outbreaks, associated with nosocomial chain of transmission, have been reported in the Kordufan region of Sudan. AIMS: To confirm CCHF in an index patient and attending physician in North Kordufan region, Sudan, and to provide some information on virus genetic lineages. METHODS: Antibody captured ELISA, reverse transcription PCR, partial S segment sequences of the virus and subsequent phylogenetic analysis were used to confirm the CCHFV infection and to determine the virus genetic lineages. RESULTS: CCHF was confirmed by monitoring specific IgM antibody and by detection of the viral genome using RT-PCR. Treatment with oral ribavirin, replacement with fluid therapy, blood transfusion and administration of platelets concentrate resulted in rapid improvement of the health condition of the female physician. Phylogenetic analysis of the partial S segment sequences of the 2 CCHFV indicates that both strains are identical and belong to Group III virus lineage, which includes viruses from Africa including, Sudan, Mauritania, South Africa and Nigeria. CONCLUSION: Further epidemiologic studies including, CCHFV complete genome analysis and implementation of improved surveillance are urgently needed to better predict and respond to CCHF outbreaks in the Kordufan region, Sudan.

Malaria and pre-eclampsia in an area with unstable malaria transmission in Central Sudan.

BACKGROUND: Placental malaria and pre-eclampsia occur frequently in women in tropics and are leading causes of maternal and perinatal morbidities and mortality. Few data exist concerning the interaction between placental malaria and pre-eclampsia. METHODS: A case control study was conducted in Medani Hospital, which locates in an area of unstable malaria transmission in Central Sudan. Case (N = 143) were women with pre-eclampsia, which was defined as systolic blood pressure ≥ 140 mm Hg or diastolic blood pressure ≥ 90 mm Hg and proteinuria. Controls were parturient women (N = 143) without any blood pressure values > 139/89 mm Hg or proteinuria. Obstetrical and medical characteristics were gathered from both groups through structured questionnaires. Placental histopathology examinations for malaria were performed. RESULTS: Twenty-eight (19.6%) vs. 16 (11.2%); P = 0.04 of the cases vs. controls, had placental malaria infections. Five (2%), 1 (2%) and 22 (28.0%) vs. 1, 2 and 13 of the placentae showed acute, chronic and past infection on histopathology examination in the two groups respectively, while 115 (80.4%) vs.127 (88.8%) of them showed no infection, P = 0.04. In multivariate analysis, while there were no associations between age, parity, educational level, lack of antenatal care, blood groups and body mass index and pre-eclampsia; family history of hypertension and placental malaria (OR = 2.3, 95% CI = 1.0-5.2; P = 0.04) were significantly associated with pre-eclampsia. CONCLUSION: Placental malaria was associated with pre-eclampsia. Further research is needed.

Cytokine profiles in children with severe Plasmodium falciparum malaria in an area of unstable malaria transmission in central Sudan.

BACKGROUND: Few data exist concerning pathogenesis of severe malaria in areas of unstable malaria transmission. OBJECTIVES: The study was conducted in Senga hospital, central Sudan, which is characterized by unstable malaria transmission to investigate the cytokine profiles in children with severe Plasmodium falciparum malaria. METHODS: Enzyme-linked immunosorbent assay was used to measure the concentrations of three cytokines, interferon gamma (IFN-γ), interleukin-4 (IL-4) and IL-10, in sera of three groups of children (31 in each arm): those with one or more manifestations of severe malaria, those children with uncomplicated P. falciparum malaria and healthy controls. RESULTS: The levels of both IFN-γ and IL-10 were significantly higher in patients with severe P. falciparum malaria. Medium positive correlations were observed between IFN-γ and IL-10. CONCLUSION: Thus, the high levels of both IFN-γ and IL-10 indicated their role in the pathogenesis of severe P. falciparum malaria.

Association between breastfeeding and preeclampsia in parous women: a case -control study.

BACKGROUND: Preeclampsia is a global health problem and it is the main cause of maternal and perinatal morbidity and mortality. Breastfeeding has been reported to be associated with lower postpartum blood pressure in women with gestational hypertension. However, there is no published data on the role that breastfeeding might play in preventing preeclampsia. The aim of the current study was to investigate if breastfeeding was associated with preeclampsia in parous women. METHOD: A case-control study was conducted in Saad Abualila Maternity Hospital in Khartoum, Sudan, from May to December 2019. The cases (n = 116) were parous women with preeclampsia. Two consecutive healthy pregnant women served as controls for each case (n = 232). The sociodemographic, medical, and obstetric histories were gathered using a questionnaire. Breastfeeding practices and duration were assessed. RESULTS: A total of 98 (84.5%) women with preeclampsia and 216 (93.1%) women in the control group had breastfed their previous children. The unadjusted odds ratio (OR) of preeclampsia (no breastfeeding vs breastfeeding) was 3.55, 95% confidence interval (CI) 1.64,7.70 and p value = 0.001 based on these numbers. After adjusting for age, parity, education level, occupation, history of preeclampsia, history of miscarriage, body mass index groups the adjusted OR was 3.19, 95% CI 1.49, 6.82 (p value = 0.006). CONCLUSION: Breastfeeding might reduce the risk for preeclampsia. Further larger studies are required.

Pathogenic Variants in ABHD16A Cause a Novel Psychomotor Developmental Disorder With Spastic Paraplegia.

Introduction: Hereditary spastic paraplegia is a clinically and genetically heterogeneous neurological entity that includes more than 80 disorders which share lower limb spasticity as a common feature. Abnormalities in multiple cellular processes are implicated in their pathogenesis, including lipid metabolism; but still 40% of the patients are undiagnosed. Our goal was to identify the disease-causing variants in Sudanese families excluded for known genetic causes and describe a novel clinico-genetic entity. Methods: We studied four patients from two unrelated consanguineous Sudanese families who manifested a neurological phenotype characterized by spasticity, psychomotor developmental delay and/or regression, and intellectual impairment. We applied next-generation sequencing, bioinformatics analysis, and Sanger sequencing to identify the genetic culprit. We then explored the consequences of the identified variants in patients-derived fibroblasts using targeted-lipidomics strategies. Results and Discussion: Two homozygous variants in ABHD16A segregated with the disease in the two studied families. ABHD16A encodes the main brain phosphatidylserine hydrolase. In vitro, we confirmed that ABHD16A loss of function reduces the levels of certain long-chain lysophosphatidylserine species while increases the levels of multiple phosphatidylserine species in patient's fibroblasts. Conclusion: ABHD16A loss of function is implicated in the pathogenesis of a novel form of complex hereditary spastic paraplegia.

Novel Homozygous Missense Mutation in the ARG1 Gene in a Large Sudanese Family.

Background: Arginases catalyze the last step in the urea cycle. Hyperargininemia, a rare autosomal-recessive disorder of the urea cycle, presents after the first year of age with regression of milestones and evolves gradually into progressive spastic quadriplegia and cognitive dysfunction. Genetic studies reported various mutations in the ARG1 gene that resulted in hyperargininemia due to a complete or partial loss of arginase activity. Case Presentation: Five patients from an extended highly consanguineous Sudanese family presented with regression of the acquired milestones, spastic quadriplegia, and mental retardation. The disease onset ranged from 1 to 3 years of age. Two patients had epileptic seizures and one patient had stereotypic clapping. Genetic testing using whole-exome sequencing, done for the patients and a healthy parent, confirmed the presence of a homozygous novel missense variant in the ARG1 gene [GRCh37 (NM_001244438.1): exon 4: g.131902487T>A, c.458T>A, p.(Val153Glu)]. The variant was predicted pathogenic by five algorithms and affected a highly conserved amino acid located in the protein domain ureohydrolase, arginase subgroup. Sanger sequencing of 13 sampled family members revealed complete co-segregation between the variant and the disease distribution in the family in line with an autosomal-recessive mode of inheritance. Biochemical analysis confirmed hyperargininemia in five patients. Conclusion: This study reports the first Sudanese family with ARG1 mutation. The reported variant is a loss-of-function missense mutation. Its pathogenicity is strongly supported by the clinical phenotype, the computational functional impact prediction, the complete co-segregation with the disease, and the biochemical assessment.

Cytokine profiles in peripheral, placental and cord blood in an area of unstable malaria transmission in eastern Sudan.

BACKGROUND: Understanding the cytokine interactions that underlie both control and disease should be helpful when investigating the pathogenesis of malaria during pregnancy. Few data exists concerning pathogenesis of malaria during pregnancy in areas of unstable malaria transmission. OBJECTIVES: The study was conducted in New Halfa hospital, eastern Sudan, which is characterized by unstable malaria transmission to investigate the cytokine profiles in peripheral, placental and cord blood in parturient women. METHODS: Enzyme-linked immunosorbent assay was used to measure the concentrations of three cytokines, interferon-gamma (IFN-gamma), interleukin-4 (IL-4) and IL-10, in sera from peripheral, placental and cord blood of 87 Sudanese women. RESULTS: The concentrations of these cytokines were significantly higher in peripheral, placental sera from uninfected women than in sera from infected women. IFN-gamma concentrations were significantly lower in the cord sera from uninfected women in comparison to the infected ones. The levels of these cytokines were not significantly different between the primiparae and multipare. Cord sera in all groups showed lower levels of these cytokines. Strong positive correlations were observed between peripheral and placental cytokines. CONCLUSION: The immune responses that occur in placental, peripheral and cord blood were influenced by the malaria infections, irrespective of the parity. The immune response during Plasmodium falciparum infection is not different in the peripheral and placental compartments, further studies are required.

In transition: current health challenges and priorities in Sudan.

A recent symposium and workshop in Khartoum, the capital of the Republic of Sudan, brought together broad expertise from three universities to address the current burden of communicable and non-communicable diseases facing the Sudanese healthcare system. These meetings identified common challenges that impact the burden of diseases in the country, most notably gaps in data and infrastructure which are essential to inform and deliver effective interventions. Non-communicable diseases, including obesity, type 2 diabetes, renal disease and cancer are increasing dramatically, contributing to multimorbidity. At the same time, progress against communicable diseases has been slow, and the burden of chronic and endemic infections remains considerable, with parasitic diseases (such as malaria, leishmaniasis and schistosomiasis) causing substantial morbidity and mortality. Antimicrobial resistance has become a major threat throughout the healthcare system, with an emerging impact on maternal, neonatal and paediatric populations. Meanwhile, malnutrition, micronutrient deficiency and poor perinatal outcomes remain common and contribute to a lifelong burden of disease. These challenges echo the United Nations (UN) sustainable development goals and concentrating on them in a unified strategy will be necessary to address the national burden of disease. At a time when the country is going through societal and political transition, we draw focus on the country and the need for resolution of its healthcare needs.

Field-based evidence for linkage of mutations associated with chloroquine (pfcrt/pfmdr1) and sulfadoxine-pyrimethamine (pfdhfr/pfdhps) resistance and for the fitness cost of multiple mutations in P. falciparum.

Mutations in the Plasmodium falciparum pfcrt gene on chromosome 7 and possibly mutations in pfmdr1 on chromosome 5 have a role in conferring resistance against chloroquine (CQ), as do mutations of pfdhfr on chromosome 4 and pfdhps on chromosome 8 in terms of resistance against sulfadoxine/pyrimethamine (SP). The additive role of multiple mutations in the development of resistance to each drug suggests a non-random occurrence. In this study, parasite isolates were obtained from 50 patients with uncomplicated P. falciparum malaria from rural Eastern Sudan, an endemic setting with minimal overlap of infection. The parasite isolates were genotyped for detection of 12 alleles in CQ and SP resistance genes. Our main findings were: (1) the frequency of mutant alleles, pfcrt K76T, pfmdr1 N86Y, pfdhfr N51I, pfdhfr S108N, pfdhps K540E and pfdhps A581G were; 0.90, 0.86, 0.84, 0.84, 0.80 and 0.20, respectively. (2) No mutations were detected for the pfdhfr loci A16V, C59R and I164L, and for pfdhps loci S436A, A437G and A613S. (3) There was a statistically significant association between the mutations in: (i) the CQ resistance (CQR) genes, pfcrt T76 and pfmdr1 Y86 (P< or =0.001), (ii) the SP resistance (SPR) genes, pfdhfr I51, pfdhfr N108 and pfdhps E540 (P< or =0.001-0.04) and (iii) the CQ "i" and SP "ii" resistance genes (P=0.001) 4. The fitness cost of multiple mutations was revealed by a significantly reduced parasite density of isolates bearing the mutant alleles (P=0.048). However, the significantly higher gametocyte carriage rate among isolates with resistance mutations (P=0.001) is possibly an evolutionary mechanism for survival of mutant parasites.

The implication of dihydrofolate reductase and dihydropteroate synthetase gene mutations in modification of Plasmodium falciparum characteristics.

BACKGROUND: The Plasmodium falciparum dihydrofolate reductase (DHFR) and dihydropteroate synthetase (DHPS) are enzymes of central importance in parasite metabolism. The dhfr and dhps gene mutations are known to be associated with sulphadoxine/pyrimethamine (SP) resistance. OBJECTIVE: To investigate the effects of dhfr/dhps mutations on parasite characteristics other than SP resistance. METHOD: Parasite infections obtained from 153 Sudanese patients with uncomplicated falciparum malaria treated with SP or SP + chloroquine, were successfully genotyped at nine codons in the dhfr/dhps genes by PCR-ELISA. RESULTS & CONCLUSION: Mutations were detected in dhfr at N51I, S108N and C59R, and in at dhps at A/S436F, A437G, K540E and A581G, the maximum number of mutations per infection were five. Based on number of mutant codons per infection (multiplicity of mutation, MOM), the infections were organized into six grades: wild-types (grade 0; frequency, 0.03) and infections with MOM grades of 1 to 5, with the following cumulative frequency; 0.97, 0.931, 0.866, 0.719, 0.121, respectively. There was no significant association between the MOM and SP response. Importantly, immunity, using age as a surrogate marker, contributed significantly to the clearance of parasites with multiple dhfr/dhps mutations. However, these mutations have a survival advantage as they were associated with increased gametocytogenesis. The above implications of dhfr/dhps mutations were associated with MOM 2 to 5, regardless of the gene/codon locus.

Allelic polymorphism of MSP2 gene in severe P. falciparum malaria in an area of low and seasonal transmission.

The severe malaria (SM) and uncomplicated malaria (UM) infections are expected to have different genetic makeup. In this study, blood samples were obtained from 325 donors with SM and UM and malaria-free donors (including asymptomatic submicroscopic malaria--ASUM), from Eastern Sudan. The SM group included patients with cerebral malaria (CM), severe malarial anemia (SMA), and other complications. The MSP2 locus was exploited for parasite genotyping. We found that the genetic diversity of the parasite population was marked (51 genotypes). The overall multiplicity of infection (MOI) was 1.5, and it was comparable between SM and UM. However, the MOI in ASUM (1.0) and fatal CM (1.14) was comparable and significantly lower than in UM (1.53), SMA (1.52), and nonfatal CM (1.7). The ratio of the IC1 to FC27 allele families was comparable between SM and UM, and the distribution of the allele sizes was correlated (correlation coefficient = 0.59 and 0.718; P < 0.001). It is interesting to note that the FC27 genotype was overrepresented in ASUM (68.2%) and was not recognized in fatal CM, while in mixed-clone infections, the clearance of IC1 after quinine treatment was faster than FC27 clearance. Finally, the composition of the multiclone infections (IC1 and FC27) was suggesting a stronger cross-immunity within rather than between MSP2 gene families.

Pregnant women carrying female fetuses are at higher risk of placental malaria infection.

BACKGROUND: The pathophysiology of the placental malaria is not fully understood. If there is a fetal sex-specific susceptibility to malaria infection, this might add to the previous knowledge on the immunology, endocrinology and pathophysiology of placental malaria infections. AIMS: This study was conducted to assess whether the sex of the fetus was associated with placental malaria infections. SUBJECTS AND METHODS: A cross-sectional study was performed including a secondary analysis of a cohort of women who were investigated for prevalence and risk factors (including fetal sex) for placental malaria in eastern Sudan. Placental histology was used to diagnose placental malaria infections. RESULTS: Among 339 women enrolled, the mean (SD) age was 25.8 (6.7) years and parity was 2.7 (2.2). Among the new born babies, 157 (46.3%) were male and 182 (53.7%) were female. Five (1.5%), 9 (2.7%) and 103 (30.4%) of the 339 placentas had active, active-chronic, past-chronic malaria infection on histopathology examination respectively, while 222 (65.5%) of them showed no malaria infection. Logistic regression analyses showed no associations between maternal age or parity and placental malaria infections. Women who have blood group O (OR = 1.95, 95% CI = 1.19-3.10; P = 0.007) and women who had female new born were at higher risk for placental malaria infections (OR = 2.55, 95% CI = 1.57-4.13; P< 0.001). CONCLUSION: Fetal gender may be a novel risk factor for placental malaria. In this work the female placentas were at higher risk for malaria infections than the male placentas.