A snapshot of Plasmodium falciparum malaria drug resistance markers in Sudan: a pilot study.

OBJECTIVES: Malaria infection is still known to be a worldwide public health problem, especially in tropical and sub-tropical African countries like Sudan. A pilot study conducted to describe the trend of P. falciparum drug resistance markers in 2017-2018 in comparison to CQ and AS/SP eras in Sudan. The Pfcrt, Pfmdr-1, Pfdhfr, and Pfdhps genes were investigated. Data deposited by the worldwide antimalarial resistance network was consulted, and the molecular markers previously reported from Sudan were analyzed. RESULTS: Drug molecular markers analysis was successfully done on 20 P. falciparum isolates. The Pfcrt K76 showed high frequency; 16 (80%). For the Pfmdr-1, 9 (45%) isolates were carrying the N86 allele, and 11 (55%) were 86Y allele. While the Y184F of the Pfmdr-1 showed a higher frequency of 184F compared to Y184; 16 (80%) and 4 (20%), respectively. In the Pfdhfr, 51I allele showed higher frequency compared to N51; 18 (90%) and 2 (10%), respectively. For S108N, 18 (90%) were 108 N and 2 (10%) were S108. In the Pfdhps, all isolates were carrying the mutant alleles; 437G and 540E. The frequency distribution of the Pfcrt, Pfmdr-1, Pfdhfr, Pfdhps was significantly different across the whole years in Sudan.

Frequency distribution of IL-17A G197A (rs2275913) and IL-17F A7488G (rs763780) polymorphisms among healthy Sudanese population.

OBJECTIVES: IL-17A G197A and IL-17F A7488G polymorphisms has been identified to be associated with the susceptibility to many diseases. This study aimed to investigate the frequency distribution of IL-17A G197A and IL-17F A7488G polymorphisms among healthy Sudanese population. A descriptive cross-sectional hospital-based molecular study conducted in different sites throughout Sudan. Two ml blood samples were collected from 717 healthy participants. Demographic data and the medical history of the participants were collected. RESULTS: Of the 717 participants, 355 (49.5%) were males and 362 (50.5%) were females, their mean age was 30.2 ± 17.2 and 32.2 ± 16.5, respectively. For IL-17A, the most frequent genotype detected among males and females was IL-17A heterozygote allele (AG); 215 (60.6%) and 194 (53.6%), respectively. Whereas, for IL-17F, the most frequent allele among males and females was the homozygote allele (AA); 298 (83.9%) for males and 322 (89.0%) for females. HWE for genotype distributions of IL-17A was showing statistical insignificance for IL-17A among males and females, P value 0.614. While HWE for IL-17F reached the equilibrium level, P value 0.048. The most frequent age group was those aged between 21 to 40 years; 281 (39.2%). Arab constituted the major ethnicity of the study participants; 418 (58.3%), P value 0.034.

Prevalence of Helicobacter pylori among Sudanese patients diagnosed with colon polyps and colon cancer using immunohistochemistry technique.

OBJECTIVES: Infection with the bacteria Helicobacter pylori has been classified as class one carcinogen associated with increasing susceptibility of gastritis and gastric carcinoma. This study is aiming at investigating the prevalence of H. pylori among colon polyps and colon cancer patients. A descriptive cross-sectional hospital-based study was conducted between February and June 2017. Sixty-nine formalin-fixed paraffin blocks collected from colon polyps and colon cancer patients to detect H. pylori using immunohistochemistry technique. RESULTS: Of the 69 patients included in the study, 39 (56.5%) males and 30 (43.5%) were females, their age ranged from 21 to 80 years with a mean age of 47.1 ± 19.7. Of the 69 colon polyps and colon cancer patients, 44 (63.8%) were diagnosed as adenocarcinoma, 10 (14.5%) colitis, 15 (21.7%) juvenile polyposis syndrome. The results of immunohistochemistry technique showed the presence of 16 (23.2%) positive patients for H. pylori infection. Of these 16, 13 (81.3%) patients were diagnosed with adenocarcinoma and 3 (18.7%) patients were diagnosed with juvenile polyps. The results of H. pylori detection among the different colon polyps and colon cancer patients were showing a statistically significant association for H. pylori infection and adenocarcinoma, P value 0.028.

Genetic polymorphism of the N-terminal region in circumsporozoite surface protein of Plasmodium falciparum field isolates from Sudan.

BACKGROUND: Malaria caused by Plasmodium falciparum parasite is still known to be one of the most significant public health problems in sub-Saharan Africa. Genetic diversity of the Sudanese P. falciparum based on the diversity in the circumsporozoite surface protein (PfCSP) has not been previously studied. Therefore, this study aimed to investigate the genetic diversity of the N-terminal region of the pfcsp gene. METHODS: A cross-sectional molecular study was conducted; 50 blood samples have been analysed from different regions in Sudan. Patients were recruited from the health facilities of Khartoum, New Halfa, Red Sea, White Nile, Al Qadarif, Gezira, River Nile, and Ad Damazin during malaria transmission seasons between June to October and December to February 2017-2018. Microscopic and nested PCR was performed for detection of P. falciparum. Merozoite surface protein-1 was performed to differentiate single and multiple clonal infections. The N-terminal of the pfcsp gene has been sequenced using PCR-Sanger dideoxy method and analysed to sequences polymorphism including the numbers of haplotypes (H), segregating sites (S), haplotypes diversity (Hd) and the average number of nucleotide differences between two sequences (Pi) were obtained using the software DnaSP v5.10. As well as neutrality testing, Tajima's D test, Fu and Li's D and F statistics. RESULTS: PCR amplification resulted in 1200 bp of the pfcsp gene. Only 21 PCR products were successfully sequenced while 29 were presenting multiple clonal P. falciparum parasite were not sequenced. The analysis of the N-terminal region of the PfCSP amino acids sequence compared to the reference strains showed five different haplotypes. H1 consisted of 3D7, NF54, HB3 and 13 isolates of the Sudanese pfcsp. H2 comprised of 7G8, Dd2, MAD20, RO33, Wellcome strain, and 5 isolates of the Sudanese pfcsp. H3, H4, and H5 were found in 3 distinct isolates. Hd was 0.594 ± 0.065, and S was 12. The most common polymorphic site was A98G; other sites were D82Y, N83H, N83M, K85L, L86F, R87L, R87F, and A98S. Fu and Li's D* test value was - 2.70818, Fu and Li's F* test value was - 2.83907, indicating a role of negative balancing selection in the pfcsp N-terminal region. Analysis with the global pfcsp N-terminal regions showed the presence of 13 haplotypes. Haplotypes frequencies were 79.4%, 17.0%, 1.6% and 1.0% for H1, H2, H3 and H4, respectively. Remaining haplotypes frequency was 0.1% for each. Hd was 0.340 ± 0.017 with a Pi of 0.00485, S was 18 sites, and Pi was 0.00030. Amino acid polymorphisms identified in the N-terminal region of global pfcsp were present at eight positions (D82Y, N83H/M, K85L/T/N, L86F, R87L/F, A98G/V/S, D99G, and G100D). CONCLUSIONS: Sudanese pfcsp N-terminal region was well-conserved with only a few polymorphic sites. Geographical distribution of genetic diversity showed high similarity to the African isolates, and this will help and contribute in the deployment of RTS,S, a PfCSP-based vaccine, in Sudan.

Identifying asymptomatic Leishmania infections in non-endemic villages in Gedaref state, Sudan.

OBJECTIVES: Infection with the causative agent of visceral leishmaniasis (VL) may be either symptomatic or asymptomatic. In this study we aimed at investigating the prevalence of asymptomatic infections of leishmania in non-endemic villages in Gedaref state, Sudan. A descriptive cross-sectional study conducted during September and October 2014. Blood samples were collected for serological and molecular analysis. Sticky-traps, knockdown spray and CDC-miniature light traps were used for the collection of sandflies. RESULTS: Ninety-Five participants were included; 52 from Abukishma, 15 Algadamblia Tirfa, 25 Abualnaja and 3 were from Algadamblia Aljabal. Females constituted 56 (58.9%) of the study participants while males were 39 (41.1%). The most frequent age group was > 40-years (54.7%). Balanites/Acacia trees were the most planted tree inside the houses; 78 (82.1%). Also, 85 (89.5%) of the participants breed animals inside the house. DAT test revealed 5 positive participants (5.2%). 4/5 DAT positive were past VL infection. PCR detected 35 (36.8%) positive participants. A total of 31/35 was considered asymptomatic infections based on PCR. Households planted Balanites/Acacia trees or breed domestic animals were found in high percentages with L. donovani PCR positive participants (60.1%, 91.4%). No statistically significant was found for VL associated risk factors and VL asymptomatic participants.

Evaluation of Cathodic Antigen Urine Tests for Diagnosis of Schistosoma mansoni Infection in Sudan.

BACKGROUND: Kato-Katz is the preferred method for the detection of Schistosoma mansoni eggs in stool. However, the sensitivity of this method is low and affected by day-to-day variation in egg excretion. Cathodic antigen urine tests have been proven to be sensitive for the diagnosis of S. mansoni infection in limited studies. AIM: To evaluate the accuracy and sensitivity of cathodic antigen urine tests for the diagnosis of S. mansoni infection. SETTING AND DESIGN: This study was conducted in the Gezira Irrigation Scheme in the Gezira State, Sudan. Both S. mansoni and Schistosoma haematobium are endemic in the Gezira State. Kab-Algidad Village situated in Al Kamleen locality was selected for the study. This is a school-based, cross-sectional, comparative study. SUBJECTS AND METHODS: Female school children, aged between 11 and 14 years who consented to participate, were enrolled in the study. Stool samples were examined using Kato-Katz technique and sodium dodecyl sulfate (SDS) digestion method. Urine samples were tested using the circulating cathodic antigen assays for the diagnosis of S. mansoni, and by centrifugation for S. haematobium. STATISTICAL ANALYSIS USED: Data were analyzed using the Scientific Package for Social Sciences version 15. RESULTS: Cathodic antigen urine tests showed similar sensitivity to SDS and higher sensitivity compared to six Kato-Katz (reference diagnostic test). CONCLUSION: Cathodic antigen urine tests is a useful tool for mapping S. mansoni and may be used to evaluate the interruption of transmission.