Nigerian Institute of Medical Research

Yaba, Nigeria

Nigerian Institute of Medical Research

Yaba, Nigeria

Time filter

Source Type

Grant
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: HEALTH-2007-2.3.2-9 | Award Amount: 3.33M | Year: 2008

The specificity of odor recognition by Anopheles gambiae odorant binding proteins (OBPs) and odorant receptors (ORs) will be investigated and correlated with quantifiable physiological and behavioral responses. For olfactory proteins involved in the detection of human hosts, OBP-OR pairs residing in common antennal olfactory sensilla and recognizing common host-related ligands will be identified using high-throughput screening assays employing purified recombinant OBPs, reconstituted insect cell-based OR expression platforms and libraries of synthetic and natural compounds. OBP crystal-based structure determination and modeling of ligand fitting into OBP and OR ligand-binding pockets will also be carried out in order to design ligand mimetics with improved binding and functional properties. The effectiveness of newly identified ligands will be established by in vivo electrophysiological and behavioral assays on female mosquitoes. Finally, lead compounds acting as disruptors of normal olfactory and host seeking mosquito behavior but lacking mammalian cell toxicity will be tested in model sites in Africa where A. gambiae (and malaria) is endemic to determine efficacy characteristics under conditions that simulate the sites of possible application of newly developed products. This approach to dissecting mosquito vector olfactory function should yield results that will enhance our understanding of the mechanisms that control odor recognition in mosquitoes. The identification of multiple disruptors of host seeking behavior of female mosquitoes will provide multiple new and effective tools to be employed in the effort to reduce the incidence of contact between the human host and the insect vector carrying the malaria parasite. Last but not least, the outcome of the proposed studies should serve as a paradigm for analogous efforts aimed at a reduction in disease transmission by other disease-carrying insect vectors.


Oluyemi A.,General Hospital | Anomneze E.,Health Gates Consultancy and Medical Services | Smith S.,Nigerian Institute of Medical Research | Fasanmade O.,University of Lagos
BMC Research Notes | Year: 2012

Background: There appears to exist a potentially important interplay between diabetes mellitus (DM) and Helicobacter pylori (H. pylori) infection. Findings from previous studies have been conflicting. Only a few studies have examined the topic in a sub-Saharan African population. This study sought to determine the prevalence of H. pylori infection among Type 2 diabetes mellitus (T2DM) patients in Lagos, Nigeria. Findings: H. pylori infection was detected in 18% of T2DM patients and 13% of controls but there was no statistical significance in this difference (p = 0.52). The prevalence of H. pylori was neither associated with the known duration of T2DM nor was it associated with age, gender, body mass index (BMI), smoking status. T2DM was not shown to be a risk factor independently associated with risk for H. pylori infection (OR = 0.87, 95% CI = 0.58-1.31, p = 0.57). Conclusions: The lack of a statistical significant difference between the H. pylori infection rates in T2DM patients and controls suggests that the infection is not increased in T2DM. Larger studies need to be conducted to confirm the study findings. © 2012 Oluyemi et al.; licensee BioMed Central Ltd.


Messenger L.A.,London School of Hygiene and Tropical Medicine | Miller N.P.,MENTOR Initiative | Adeogun A.O.,Nigerian Institute of Medical Research | Awolola T.S.,Nigerian Institute of Medical Research | Rowland M.,London School of Hygiene and Tropical Medicine
Malaria Journal | Year: 2012

Background: Durable lining (DL) is a deltamethrin-impregnated polyethylene material, which is designed to cover domestic walls that would normally be sprayed with residual insecticide. The operational success of DL as a long-lasting insecticidal substrate will be dependent on a high level of user acceptability as households must maintain correctly installed linings on their walls for several years. Preliminary trials were undertaken to identify a material to develop into a marketable wall lining and to assess its level of acceptability among rural and urban populations. Methods. In Angola (n=60), prototype DL and insecticide-treated plastic sheeting (ITPS) were installed on urban house walls and ceilings, respectively, and acceptability was compared to indoor residual spraying (IRS) (n=20) using a knowledge, attitude and practice (KAP) questionnaire. In Nigeria (n=178), three materials (prototype DL, ITPS and insecticide-treated wall netting) were distributed among rural and urban households. User opinions were gathered from focus group discussions, in-depth interviews and KAP questionnaires. Results: In Angola, after two weeks, the majority of participants (98%) expressed satisfaction with the products and identified the killing of insects as the materials principal benefits (73%). After one year, despite a loss of almost 50% of households to refugee repatriation, all 32 remaining households still asserted that they had liked the DL/ITPS in their homes and given the choice of intervention preferred DL/ITPS to IRS (94%) or insecticide-treated nets (78%). In Nigeria, a dichotomy between rural and urban respondents emerged. Rural participants favoured wall adornments and accepted wall linings because of their perceived decorative value and entomological efficacy. By contrast, urban households preferred minimal wall decoration and rejected the materials based upon objections to their aesthetics and installation feasibility. Conclusions: The high level of acceptability among rural inhabitants in Nigeria identifies these communities as the ideal target consumer group for durable wall linings. The poorer compliance among urban participants suggests that wall linings would not be readily adopted or sustained in these regions. If DL is as well received by other rural populations it could overcome some of the logistical constraints associated with spray campaigns and has the potential to become a long-lasting alternative to IRS in malaria endemic areas. © 2012 Messenger et al.; licensee BioMed Central Ltd.


Agomo C.O.,University of Lagos | Agomo C.O.,Nigerian Institute of Medical Research | Oyibo W.A.,University of Lagos
Infectious Diseases of Poverty | Year: 2013

Background: Pregnant women living in an area of stable malaria transmission such as Lagos, Nigeria, have been identified as being at an increased risk of the effects of malaria infection. In this area, most of the infections are asymptomatic which means they are overlooked and untreated much to the detriment of the mother and her foetus. The reality of scaled-up malaria interventions with long-lasting insecticide treated nets, vector control, artemisinin combination therapy (ACT) and intermittent preventive treatment of malaria pregnancy (IPTp) using sulphadoxine pyrimethamine (SP) is that it is also essential to determine the risk factors at play in these kinds of circumstances. This study was aimed at identifying the factors associated with risk of malaria infection in pregnant women in Lagos, Southwest Nigeria. Methods: Demographic information and malaria prevention practices of the pregnant women studied were captured using structured questionnaire. Microscopy was used to establish malaria infection, species identification and parasite density. Relative risk and multivariate logistic regression analysis were used to compare factors associated with malaria in pregnant women. Results: Malaria microscopy details, demographic information and malaria prevention practices of the pregnant women were obtained using a structured questionnaire. The prevalence of malaria using peripheral blood from 1,084 pregnant women that participated in the study was 7.7%. Plasmodium falciparum (P. falciparum) was seen in 95.2% of the cases as either mixed infection with P. malariae (3.6%) or as a mono infection (91.6%). Malaria preventive practices associated with a significant reduction (P<0.05) in the malaria infection was the use of insecticide sprays (RR = 0.36, 95 C.I. 0.24-0.54), and the combined use of insecticide spray and insecticide-treated nets (ITN) (RR= 6.53, 95% C.I. 0.92-46.33). Sleeping under ITN alone (RR = 1.07, 95% C.I. 0.55-2.09) was not associated with significant reduction in malaria infection among the study participants with malaria parasitaemia. Young maternal age (<20years) (RR = 2.86, 95% C.I. 1.48 - 5.50), but not primigravidity (RR = 1.36, 95% C.I. 0.90-2.05), was associated with an increased risk of malaria infection during pregnancy. After a multivariate logistic regression, young maternal age (OR = 2.61, 95% C.I. 1.13 - 6.03) and the use of insecticide spray (OR = 0.38, 95% C.I. 0.24-0.63) were associated with an increase and a reduction in malaria infection, respectively. Conclusion: Malaria prevalence was low among the pregnant women studied. Young maternal age and non-usage of insecticidal spray were the main factors associated with an increased risk of malaria infection among pregnant women in Lagos, Nigeria. © 2013 Agomo and Oyibo; licensee BioMed Central Ltd.


Chigor V.N.,University of Nigeria | Umoh V.J.,Ahmadu Bello University | Smith S.I.,Nigerian Institute of Medical Research
African Journal of Biotechnology | Year: 2010

Concerns about the persistence of Escherichia coli O157 in irrigation waters and its transmission to fresh produce makes investigation of irrigation waters imperative. The prevalence of this pathogen and seasonal levels of water quality parameters in Kubanni River were studied, using standard methods, over a 10-month period. Detection rate for E. coli O157 confirmed by slide agglutination was 2.1%. Faecal coliform counts (FCC) exceeded acceptable limits and was significantly higher in the dry season than during the rainy season (p<0.05). Remarkably, nitrate level was significantly higher in the rainy season than dry season (p<0.05). A significant (p<0.05) correlation was established between FCC and each of nitrate (r = 0.25), biochemical oxygen demand (r = 0.51) and electrical conductivity (r = 0.55). It was concluded that the Kubanni River represents a potential public health risk, being unfit for fresh produce irrigation. Perhaps, this is the first report on the isolation of E. coli O157 from water sources in Nigeria. © 2010 Academic Journals.


Smith S.I.,Nigerian Institute of Medical Research
The West Indian medical journal | Year: 2011

This study was carried out to screen the use of Helicobacter pylori stool antigen (HpSA) tests for diagnosis and monitoring of H pylori in Nigeria. Seven hundred and forty participants were enrolled after informed consent was obtained, while 83 came back for a post-eradication test. The stool samples were taken from the patients at endoscopy and tested for HpSA. The proportion of patients that were positive at the pretest, 520 (70.3%) was significantly higher (Fisher's exact p = 0.001) than those positive at the post-test, 44 (53%). There was a significant difference (F = 4.106, p = 0.043) between the mean age of those that came for the pretest (40.0 +/- 14.5 years) and those that came for the post-test, 43.6 +/- 11.6 years. More males than females had the tendency to come back for a post-eradication test. Although potential bias was introduced during this study, HpSA using monoclonal antibody could still be used for diagnosis and monitoring of H pylori in Nigeria.


Iwalokun B.A.,Nigerian Institute of Medical Research
Saudi journal of kidney diseases and transplantation : an official publication of the Saudi Center for Organ Transplantation, Saudi Arabia | Year: 2012

Studies have identified microalbuminuria (MA) and asymptomatic bacteruria (ASB) as co-morbid factors in sickle cell anemia (SCA). However, the relationship between these comorbid factors remains unclear and data are lacking for Nigerian patients. This study determined the prevalence of MA and ASB in a cohort of patients with SCA in a steady state, in Lagos, Nigeria. Early morning mid-stream urine samples were collected in sterile bottles from 103 patients comprising 48 males and 55 females with a mean age of 10.4 years. Aerobic culture and colony count of organisms was done using conventional methods. Serum creatinine and hematological indices, including irreversibly sickled cells (ISC), were also assayed. Of the 103 urine samples screened, 23 (22.3%) had albuminuria (ALB), and consisted of nine males and 14 females (P > 0.05); 16.5% of the cases had MA (P <0.05). Age at onset of MA was seven years, and children accounted for 23.5% of all cases with ALB (P >0.05). The prevalence of confirmed ASB was 14.6%, with females accounting for 14 of 19 probable ASB cases (P <0.05). Univariate regression analysis demonstrated a significant (P <0.05) association between age at onset of MA, hemoglobin level, reticulocyte count, ISC and occurrence of ASB, but with only ISC evolving as an independent predictor. Twenty-eight bacterial isolates predominated by Escherichia coli (39.3%; P <0.05), of whom 89.3% were multi-drug resistant, were recovered from the ASB urine samples. In conclusion, both MA and ASB are common in Nigerian SCA patients, with the former occurring from the first decade of life.


Fischer W.,Max Von Pettenkofer Institute | Breithaupt U.,Max Von Pettenkofer Institute | Kern B.,Max Von Pettenkofer Institute | Smith S.I.,Nigerian Institute of Medical Research | And 2 more authors.
BMC Genomics | Year: 2014

Background: The human gastric pathogen Helicobacter pylori is a paradigm for chronic bacterial infections. Its persistence in the stomach mucosa is facilitated by several mechanisms of immune evasion and immune modulation, but also by an unusual genetic variability which might account for the capability to adapt to changing environmental conditions during long-term colonization. This variability is reflected by the fact that almost each infected individual is colonized by a genetically unique strain. Strain-specific genes are dispersed throughout the genome, but clusters of genes organized as genomic islands may also collectively be present or absent.Results: We have comparatively analysed such clusters, which are commonly termed plasticity zones, in a high number of H. pylori strains of varying geographical origin. We show that these regions contain fixed gene sets, rather than being true regions of genome plasticity, but two different types and several subtypes with partly diverging gene content can be distinguished. Their genetic diversity is incongruent with variations in the rest of the genome, suggesting that they are subject to horizontal gene transfer within H. pylori populations. We identified 40 distinct integration sites in 45 genome sequences, with a conserved heptanucleotide motif that seems to be the minimal requirement for integration.Conclusions: The significant number of possible integration sites, together with the requirement for a short conserved integration motif and the high level of gene conservation, indicates that these elements are best described as integrating conjugative elements (ICEs) with an intermediate integration site specificity. © 2014 Fischer et al.; licensee BioMed Central Ltd.


Ezechi O.C.,Nigerian Institute of Medical Research
BMC public health | Year: 2013

The proven benefit of integrating cervical cancer screening programme into HIV care has led to its adoption as a standard of care. However this is not operational in most HIV clinics in Nigeria. Of the various reasons given for non-implementation, none is backed by scientific evidence. This study was conducted to assess the willingness and acceptability of cervical cancer screening among HIV positive Nigerian women. A cross sectional study of HIV positive women attending a large HIV treatment centre in Lagos, Nigeria. Respondents were identified using stratified sampling method. A pretested questionnaire was used to obtain information by trained research assistants. Obtained information were coded and managed using SPSS for windows version 19. Multivariate logistic regression model was used to determine independent predictor for acceptance of cervical cancer screening. Of the 1517 respondents that returned completed questionnaires, 853 (56.2%) were aware of cervical cancer. Though previous cervical cancer screening was low at 9.4%, 79.8% (1210) accepted to take the test. Cost of the test (35.2%) and religious denial (14.0%) were the most common reasons given for refusal to take the test. After controlling for confounding variables in a multivariate logistic regression model, having a tertiary education (OR = 1.4; 95% CI: 1.03-1.84), no living child (OR: 1.5; 95% CI: 1.1-2.0), recent HIV diagnosis (OR: 1.5; 95% CI: 1.1-2.0) and being aware of cervical cancer (OR: 1.5; 95% CI: 1.2-2.0) retained independent association with acceptance to screen for cervical cancer. The study shows that HIV positive women in our environment are willing to screen for cervical cancer and that the integration of reproductive health service into existing HIV programmes will strengthen rather than disrupt the services.


Ezechi O.C.,Nigerian Institute of Medical Research
African journal of reproductive health | Year: 2013

While the effect of HIV infection on some maternal outcomes is well established, for some others there is conflicting information on possible association with HIV. In this study we investigated pregnancy and neonatal outcome of HIV positive women in large HIV treatment centre over a period of 84 months. They were managed according to the Nigerian PMTCT protocol. Adverse obstetric and neonatal outcome were observed in 48.3% HIV positives compared 30.3% to the negatives (OR: 2.08; CI: 1.84-2.34). Low birth weight ( OR:2.95; CI:1.95-3.1), preterm delivery (OR:2.05; CI:1.3-3.1), perinatal death (OR:1.9;CI:1.3-3.2), and spontaneous abortion (OR:1.37; CI:1.1-2.3) were factors found to be independently associated with HIV. Low CD4 count (OR: 2.45; CI: 1.34- 4.56) and opportunistic infections (OR: 2.11; CI: 1.56-3.45) were to be associated with adverse obstetric and neonatal outcome. This study confirms the association of HIV, severe immunosuppression and opportunistic infection and adverse obstetric and neonatal outcome.

Loading Nigerian Institute of Medical Research collaborators
Loading Nigerian Institute of Medical Research collaborators