BackgroundIn the Sudan, Schistosoma mansoni infections are a major cause of morbidity in school-aged children and infection rates are associated with available clean water sources. During infection, immune responses pass through a Th1 followed by Th2 and Treg phases and patterns can relate to different stages of infection or immunity.MethodologyThis retrospective study evaluated immunoepidemiological aspects in 234 individuals (range 4–85 years old) from Kassala and Khartoum states in 2011. Systemic immune profiles (cytokines and immunoglobulins) and epidemiological parameters were surveyed in n = 110 persons presenting patent S. mansoni infections (egg+), n = 63 individuals positive for S. mansoni via PCR in sera but egg negative (SmPCR+) and n = 61 people who were infection-free (Sm uninf). Immunoepidemiological findings were further investigated using two binary multivariable regression analysis.Principal FindingsNearly all egg+ individuals had no access to latrines and over 90% obtained water via the canal stemming from the Atbara River. With regards to age, infection and an egg+ status was linked to young and adolescent groups. In terms of immunology, S. mansoni infection per se was strongly associated with increased SEA-specific IgG4 but not IgE levels. IL-6, IL-13 and IL-10 were significantly elevated in patently-infected individuals and positively correlated with egg load. In contrast, IL-2 and IL-1β were significantly lower in SmPCR+ individuals when compared to Sm uninf and egg+ groups which was further confirmed during multivariate regression analysis.Conclusions/SignificanceSchistosomiasis remains an important public health problem in the Sudan with a high number of patent individuals. In addition, SmPCR diagnostics revealed another cohort of infected individuals with a unique immunological profile and provides an avenue for future studies on non-patent infection states. Future studies should investigate the downstream signalling pathways/mechanisms of IL-2 and IL-1β as potential diagnostic markers in order to distinguish patent from non-patent individuals.

Infections withSchistosoma mansoni remain a major health problem in the Sudan where endemic communities, such as those in Kassala and Khartoum states, continue to face severe social-economic difficulties. Our previous immunoepidemiological findings revealed different immune [cytokine and S. mansoni egg (SEA) antibody] profiles in individuals with active infections (eggs in stool n = 110), individuals positive for S. mansoni via polymerase chain reaction (PCR) using sera (Sm PCR + n = 63) and those uninfected (Sm uninf). As antibody responses to eggs and worms are known to change during infection, we have expanded the profiling further by determining levels of adult worm (SWA) antibodies and nine chemokines in the serum of each individual in the three different cohorts.With the exception of C-C motif chemokine ligand (CCL)2, all measured chemokines were significantly higher in SmP CR + individuals when compared to the egg + group and in addition they also presented elevated levels of SWA-specific immunoglobulin (Ig)G2. Multivariable regression analysis further revealed that infection per se was strongly linked to SWA-specific IgG3 levels and CCL5 was strongly associated with a Sm PCR + diagnostic state. In the absence of PCR diagnostics that recognize juvenile worms or schistosomulae motives, identifying schistosome-specific traits should provide better insights into current prevalence rates in endemic communities and, in doing so, take into consideration PCR + non-egg + individuals in current treatment programmes.

Background: Intestinal parasite spread in tropical countries is especially common among primary school students. This study aimed to determine the frequencies of the intestinal parasite by different techniques among school students in Alkalakla locality, Khartoum state. Methods: This study was conducted in school students in Al-kalakla locality in Khartoum state from period between 20th December 2016 to 5th May 2017. Stool samples were collected from 134 randomly selected students, of whom 67 were males and 67 were females.  All samples were examined using the wet preparation technique, formal ether concentration technique and saturated sugar floatation technique. Results: The frequency of intestinal parasites was 35.5% overall in the students examined; females were more affected than males (38.8% and 32.8%, respectively). The more affected age groups were 12-14 years followed by 9-11 and 6-8 years old (53.8%, 36.3% and 26.4% respectively). The least frequent intestinal parasite was Taenia spp. (1.5%) followed by Giardia lamblia (3.7%), Schistosoma mansoni and Ascaris lumbricoides (5.2% each), Entamoeba coli (7.5%), Hymenolepis nana (10.4%), and Entamoeba histolytica (16.4%). In total, 20.9% were infected with single parasite while 14.9% were infected with more than one parasite. The frequency of parasite by formal ether concentration method was 35.8 %, by wet preparation method was 17.9 % and by the saturated sugar flotation method was 16.4%. Conclusion: Our data showed that intestinal parasites were common in school students; however, females were more affected than males and the 12-14-years age group was the most affected age group.  The formal ether concentration method was the best method for detecting of intestinal parasite.

Background: The cytokines interferon gamma (IFN-γ), interleukin-10 (IL-10) and tumor necrosis factor-α (TNF- α) play an important role in malaria infection. The aim of this study was to determine the prevalence of malaria and to evaluate cytokine responses to malaria infection in patients from the East Nile locality of Khartoum State. Methods: This study was carried out from May to July 2018 in the East Nile Locality, Khartoum State. Blood samples were collected from 384 randomly selected patients for blood film analysis. Of these, 39 were selected for cytokine level analysis (10 control and 29 patient samples), determined using enzyme-linked immunosorbent assays. Results: The malaria prevalence rate among 384 patients was 18.5%. Plasmodium falciparum was the most prevalent (13%), while the prevalence of Plasmodium vivax was 4.6%. The rate of mixed infection was 0.8%. There was a higher prevalence rate (22.7%) in males than females (15.6%). However, we found no significant correlation between cytokine levels and parasitemia in the study group. Nevertheless, our study demonstrated a significant correlation between cytokine levels and recurrent infections. Conclusions: Together, our data show that malaria remains a public health problem in East Nile locality with a high prevalence. Additionally, cytokine levels were found to be correlated with recurrent malaria infection.