Regulatory T Cells and Parasites

Human host encounters a wide array of parasites; however, the crucial aspect is the failure of the host immune system to clear these parasites despite antigen recognition. In the recent past, a new immunological concept has emerged, which provides a framework to better understand several aspects of host susceptibility to parasitic infection. It is widely believed that parasites are able to modulate the magnitude of effector responses by inducing regulatory T cell (Tregs) population and several studies have investigated whether this cell population plays a role in balancing protective immunity and pathogenesis during parasite infection. This review discusses the several mechanism of Treg-mediated immunosuppression in the human host and focuses on the functional role of Tregs and regulatory gene polymorphisms in infectious diseases

Perception and Treatment Practices of malaria among tertiary institution students in Oyo and Osun States, Nigeria

The knowledge, prevention and practices on malaria treatment measures were assessed among 643 tertiary students in Osun and Oyo States in Nigeria. Data were collected using well-structured questionnaires. The study observed that the respondents are aware of the common symptoms of malaria as 26.4% recognised fever as the most noticeable sign of malaria. On the other hand, the knowledge of the severe symptoms of malaria was poor as only 13.1%, 13.5% and 7.9% were aware that convulsion, coma and anaemia respectively were severe symptoms of malaria. Surprisingly very few (14.6%) believed that dirty environment could cause malaria. The knowledge (23.4%) and the use (22.1%) of insecticide treated bed net was low in the studied population. More respondents used Coartem (20.1%; p= 0.002) for malaria treatment than any other drug and most of them will take prescription (67.5%) from a medical personnel. Also, most of the respondents (60.8%) will not go for malaria diagnostic test before taking malaria drug and the difference was highly significant (p=0.001). It is therefore suggested that more efforts should be invested in enlightening the populace on practises that will influence their behavioural pattern in a way that will lead to effective malaria control. Keywords: Malaria, prevention, practices, symptom

Prevalence and associated factors of Plasmodium falciparum and soil transmitted helminth infections among pregnant women in Osun state, Nigeria

Background: Plasmodium falciparum and soil transmitted helminth (STHs) infection are widespread in sub-Sahara Africa, where co-infection is also common. This study assessed the prevalence of these infections and their risk factors among pregnant women in Osogbo, Nigeria.Methods: A total of 200 pregnant women attending the antenatal clinic were recruited. Plasmodium falciparum was detected using thick and thin film methods, while formol ether concentration method was used for STHs detection. A questionnaire was used to investigate the possible risk factors associated with acquisition of malaria and helminth infections.Results: The prevalence of P. falciparum, STHs and their co-infection was 29.5%, 12% and 5% respectively. P. falciparum, STHs and P. falciparum + STHs co-infection was significantly higher in primigravidae (52.5% vs 58.3% vs 80%) than in secongravidae (18.6% vs 25.0% vs 20%) and multigravidae (28.8% vs 16.7% vs 0%) (p=0.02). Prevalence associated factors identified for P. falciparum was age (p=0.0001) while gravidity (p=0.02) was identified for P. falciparum + STHs co-infection.Conclusion: High prevalence of P. falciparum and helminth infections was observed among the pregnant women with primigravidae being the most susceptible to co-infection. There is an urgent need to implement an effective malaria and STHs preventive method for this high risk population.Keywords: P.falciparum, STHs, Co-infection, pregnant women, Nigeria

Prevalence and associated factors of Plasmodium falciparum and soil transmitted helminth infections among pregnant women in Osun state, Nigeria

Background: Plasmodium falciparum and soil transmitted helminth (STHs) infection are widespread in sub-Sahara Africa, where co-infection is also common. This study assessed the prevalence of these infections and their risk factors among pregnant women in Osogbo, Nigeria. Methods: A total of 200 pregnant women attending the antenatal clinic were recruited. Plasmodium falciparum was detected using thick and thin film methods, while formol ether concentration method was used for STHs detection. A questionnaire was used to investigate the possible risk factors associated with acquisition of malaria and helminth infections. Results: The prevalence of P. falciparum, STHs and their co-infection was 29.5%, 12% and 5% respectively. P. falciparum, STHs and P. falciparum + STHs co-infection was significantly higher in primigravidae (52.5% vs 58.3% vs 80%) than in secongravidae (18.6% vs 25.0% vs 20%) and multigravidae (28.8% vs 16.7% vs 0%) (p=0.02). Prevalence associated factors identified for P. falciparum was age (p=0.0001) while gravidity (p=0.02) was identified for P. falciparum + STHs co-infection. Conclusion: High prevalence of P. falciparum and helminth infections was observed among the pregnant women with primigravidae being the most susceptible to co-infection. There is an urgent need to implement an effective malaria and STHs preventive method for this high risk population

Genetic Diversity of CD14 Promoter Gene Polymorphism (rs2569190) is Associated With Regulation of Malaria Parasitemia and Susceptibility to Plasmodium falciparum Infection.

CD14 is a multifunctional receptor expressed on many cell types and has been shown to mediate immune response resulting in the activation of an inflammatory cascade, with polymorphism of its promoter (rs2569190) found to be associated with susceptibility to several diseases. In malaria infection, the CD14 gene demonstrated a pathogenic profile in regulating experimental cerebral malaria, with reports of elevated levels of soluble CD14 in serum of patients but no definitive conclusion. We present a detailed analysis of genetic diversity of CD14 promoter gene (snp −159 C/T; rs2519190) polymorphism between a malaria-infected group and uninfected controls and its association with clinical parameters of disease. Genomic DNA samples obtained from 106 Plasmodium falciparum malaria–infected patients and 277 uninfected controls were elucidated with a polymerase chain reaction-restriction fragment length polymorphism (RFLP) assay. Our results show a significant diversity (P=3.32E−06) in the genotypic frequency (3.8% versus 22.4%) of the rs2569190 mutant variant between the malaria-infected group and controls, respectively. The mutant allele had the lowest frequency among the malaria-infected group demonstrating its necessity for infection. Mean parasitemia (parasites/μL of blood) was significantly regulated based on CD14 polymorphic profile (19 855 versus 37 041 versus 49 396 for homozygote mutants, heterozygotes, and homozygote wild type, respectively). Interestingly, we found no association between CD14 genetic variants with fever, age of patients, or anemia. How this affects disease severity between subregional and continental groups deserves further clarification, including extending these studies in a larger group and among severe and asymptomatic patients with malaria

Rapid detection of Pfcrt and Pfmdr1 mutations in Plasmodium falciparum isolates by FRET and in vivo response to chloroquine among children from Osogbo, Nigeria

BACKGROUND: Chloroquine (CQ) has been in use in Africa for a long time. Because of misuse, this drug has now lost its efficacy due to the emergence of resistance strains in most parts of Africa. Recently, it was shown that after chloroquine has been withdrawn from the market, chloroquine-sensitive Plasmodium falciparum re-emerged and chloroquine could again be used successfully as an antimalarial. Surveillance of parasite populations is, therefore, important to decide whether chloroquine could be re-introduced. METHODS: To estimate the prevalence of the most pivotal polymorphisms, including Pfcrt K76T, Pfmdr1 N86Y and Pfmdr1 Y184F mutations, and their contributions to the outcome of CQ treatment, isolates from Osogbo Western Nigeria were tested using the Fluorescence Resonance Energy Transfer (FRET) method on a real-time PCR instrument. RESULTS: 116 children with acute uncomplicated P. falciparum malaria infections were treated with the standard dosage of CQ and followed-up for 28 days. Blood samples were collected on filter paper at enrollment and during follow-up for identification of parasite carrying the chloroquine resistant transporter (pfcrt) and P. falciparum-multi drug resistance (pfmdr1) gene mutations. Parasitological assessment of response to treatment showed that 62% of the patients were cured and 38% failed the CQ treatment. The presence of single mutant pfcrt (T76) alleles (P = 0.003) and in combination with mutant pfmdr1 Y86 (P = 0.028) was significantly associated with in vivo CQR. No other mutation on its own or in combinations was significantly associated with treatment outcome. Mutant pfcrt was more prevalent in both pre- and post-treatment isolates. No association was observed between age or initial level of parasitaemia and chloroquine treatment outcome. CONCLUSION: The result established the usefulness and accuracy of real time PCR in pfcrt and pfmdr1 mutation detection and also give further evidence to the reliability of the pfcrt T76 point mutation as a molecular marker for CQ resistance

Phenotypic and Molecular Characterisation of Extended-Spectrum Beta-Lactamase Producing Escherichia coli

Production of extended-spectrum β-lactamases (ESBLs) producing E. coli in animals and different methods of identifications from Ado Ekiti, Ekiti State, Nigeria, were investigated. Three hundred and fifty fecal samples, collected from apparently healthy cattle and pigs, were cultured and identified following standard procedures. ESBL phenotypic detection was carried out using combination disc test, double disc synergism test, and ESBL brilliance agar screening. Molecular detection of TEM, SHV, and CTX-M genes was carried out using standard molecular method. One hundred and fourteen E. coli isolates were recovered from the 350 samples processed, out of which 72 (63.2%) isolates were positive for ESBLs with multiple resistance to the antibiotics used. Eighty-one (71%) isolates were positive for ESBL by combination disc test, 90 (78.9%) were positive for double disc synergism test, and 93 (81.6%) were positive for ESBL brilliance agar. TEM and CTX-M genes were detected in 48 (42.1%) and 51 (44.7%) isolates, respectively. SHV gene was not detected in any of the isolates while TEM and CTX-M were detected in 33 (28.9%) isolates. This study showed high resistance of E. coli to antibiotics, particularly to the third generation cephalosporins. Regular monitoring and regulated use of antibiotics in livestock should be encouraged

Phenotypic and Molecular Characterisation of Extended-Spectrum Beta-Lactamase ProducingEscherichia coli Obtained from Animal Fecal Samples in Ado Ekiti, Nigeria

Production of extended-spectru

Ethanol Extract of Blighia Sapida Stem Bark Show Remarkable Prophylactic Activity in Experimental Plasmodium berghei-Infected Mice.

This work explores the antiplasmodial potential of ethanol extract of Blighia sapida (Lin. Sapindaceae) in chloroquine (CQ)- resistant Plasmodium berghei (ANKA strain)–infected mice. Chloroquine-resistant (ANKA) strain of P berghei was inoculated intraperitoneally into Swiss albino mice. Mice were treated orally for 4 consecutive days, before and after inoculation (prophylactic, suppressive, and curative models) with graded doses of the plant extracts with Artemether-Lumefantrine (Coartem) as control. Prophylactically, the extract showed a remarkable activity in the chemosuppression of P berghei parasites (

Hepatitis E virus infection in high-risk populations in Osun State, Nigeria

Hepatitis E virus (HEV) infection is an emerging infection that is of major public health concern, especially in some vulnerable groups like immunosuppressed individuals, pregnant women and HBV-coinfected individuals. HEV is transmitted faecal/oral or zoonotically depending on the HEV-genotype. This study aimed at investigating HEV infections among different at-risk populations in Osun State, Southwestern Nigeria. A total of 720 serum samples were collected from animal handlers, pregnant women, people living with HIV/AIDS, and Hepatitis B virus (HBV) infected individuals. Commercially available Enzyme-Linked Immunosorbent Assays (ELISA) were used for the detection of anti-HEV total and IgM antibodies. Polymerase chain reaction (PCR) was carried out in the HEV seropositive samples and all the samples from individuals infected with HBV. Descriptive analysis and chi-square test of association were performed. The anti-HEV total antibody seroprevalence in HIV-positive individuals, animal handlers and pregnant women was 11.4% (n = 47/411), 7.9% (n = 7/89), and 6.3% (n = 10/160), respectively. Markers of acute HEV infection (anti-HEV IgM) were detected in 2.2% of HIV-positive individuals (n = 9/411) and 1.8% of animal handlers (n = 2/89), respectively, and in 0.6% of pregnant women (n = 1/160). However, all samples were HEV RNA negative. This study analysed the presence of markers of HEV infection among different at-risk populations without clinical symptoms of HEV infection. Our results showed that HEV is an underestimated threat to public health in Nigeria and underlines the need of an HEV surveillance system to understand the distribution and transmission of HEV infection in animals and/to humans.Peer Reviewe