Bamidele A. Iwalokun

Specific Viruses Detected in Nigerian Children in Association with Acute Respiratory Disease

Occurrence of different viruses in acute respiratory tract infections of Nigerian children was examined. Respiratory swabs were collected from 246 children referred to hospital clinics because of acute respiratory symptoms from February through May 2009. Validated real-time RT-PCR techniques revealed nucleic acids of at least one virus group in 189 specimens (77%). Human rhinoviruses and parainfluenza viruses were present each in one third of the children. Adenoviruses, enteroviruses, human metapneumovirus, human bocavirus, and influenza C virus were also relatively common. Possibly due to their seasonal occurrence, influenza A and B virus, and respiratory syncytial virus were detected rarely. We conclude that all major groups of respiratory tract viruses are causing illness in Nigerian children.

bla CTX-M-I group extended spectrum beta lactamase-producing Salmonella typhi from hospitalized patients in Lagos, Nigeria

Purpose The global spread of blaCTX-M-I extended-spectrum beta-lactamase (ESBL)-producing Salmonella spp. remains a major threat to treatment and control. Evidence of emergence and spread of this marker are lacking in Nigeria. This study investigated blaCTX-M-I ESBL production among Salmonella isolates from hospitalized patients. Methods Patients (158 total) made up of two groups were evaluated. Group A was composed of 135 patients with persistent pyrexia and group B was composed of 23 gastroenteritis patients and their stool samples. Samples were cultured, and isolates were identified and were subjected to antibiotic susceptibility testing by standard methods. Isolates were further screened for ESBL production, blaCTX-M-I genes and transferability by double disk synergy test, plasmid extraction, polymerase chain reaction, and conjugation experiment. Results Thirty-five (25.9%) Salmonella isolates were identified from group A, of which 74.3% were S. typhi, 22.9% were S. paratyphi and two (5.7%) were invasive non-typhoidal S. enteritidis. Nine Plasmodium falciparum infections were recorded, four of which were identified as co-infections with typhoidal Salmonella. Only two (8.7%) S. enteritidis samples were obtained from group B (P>0.05). A total of 24 isolates were ESBL-positive, eliciting resistance to five to seven antibiotics, and were multiple-drug resistant. ESBL production due to the blaCTX-M-I gene cluster was detected in eleven (45.8%) Salmonella isolates. Nine (81.8%) of the eleven blaCTX-M-I ESBL producers were S. typhi and two (18.2%) isolates were S. enteritidis. Four of nine S. typhi blaCTX-M-I ESBL-producing strains harbored 23 kb self-transmissible plasmid that was co-transferred with cefotaxime and augmentin resistance to Escherichia coli j53-2 transconjugants. Conclusion This study revealed the emergence of blaCTX-M-I S. typhi as an agent of persistent pyrexia with potential to spread to other Enterobacteriaceae in Lagos, Nigeria. Cautionary prescription and judicious use of third-generation cephalosporins, particularly cefotaxime, for the treatment of typhoid fever and routine screening for P. falciparum co-infection with ESBL-producing Salmonella in the laboratories during diagnosis of persistent pyrexia conditions in patients are recommended.

Malariometric Survey of Ibeshe Community in Ikorodu, Lagos State: Dry Season

Malariometric surveys generate data on malaria epidemiology and dynamics of transmission necessary for planning and monitoring of control activities. This study determined the prevalence of malaria and the knowledge, attitude, and practice (KAP) towards malaria infection in Ibeshe, a coastal community. The study took place during the dry season in 10 villages of Ibeshe. All the participants were screened for malaria. A semistructured questionnaire was used to capture sociodemographic data and KAP towards malaria. A total of 1489 participants with a mean age of 26.7 ± 20.0 years took part in the study. Malaria prevalence was 14.7% (95% CI 13.0–16.6%) with geometric mean density of 285 parasites/μL. Over 97% of participants were asymptomatic. Only 40 (2.7%) of the participants were febrile, while 227 (18.1%) were anemic. Almost all the participants (95.8%) identified mosquito bite as a cause of malaria, although multiple agents were associated with the cause of malaria. The commonest symptoms associated with malaria were hot body (89.9%) and headache (84.9%). Window nets (77.0%) were preferred to LLIN (29.6%). Malaria is mesoendemic in Ibeshe during the dry season. The participants had good knowledge of symptoms of malaria; however, there were a lot of misconceptions on the cause of malaria.

Evaluation of microalbuminuria in relation to asymptomatic bacteruria in Nigerian patients with sickle cell anemia.

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.

Genetic diversity and complexity of Plasmodium falciparum infections in Lagos, Nigeria.

OBJECTIVE To analyse the genetic diversity of Plasmodium falciparum (P. falciparum) using msp-1 and msp-2 as antigenic markers. METHODS Parasite DNA was extracted from 100 blood samples collected from P. falciparum-positive patients confirmed by microscopy, and followed by PCR-genotyping targeting the msp-1 (block2) and msp-2 (block 3) allelic families. RESULTS All the families of msp-1 (K1, MAD20 and R033) and msp-2 (FC27 and 3D7) locus were observed. Results revealed that K1 (60/100) was the most predominant genotype of msp-1 allelic family followed by the genotypes of MAD20 (50/100) and R033 (45/100). In the msp-2 locus, FC27 genotype (62/100) showed higher frequency than 3D7 genotype (55/100). The allelic families were detected either alone or in combination with other families. However, no R033/MAD20 combination was observed. Multiplicity of infection (MOI) with msp-1 was higher in the locality of Ikorodu (1.50) than in Lekki (1.39). However, MOI with msp-2 was lower in the locality of Ikorodu (1.14) than in Lekki (1.76). There was no significant difference in the mean MOI between the two study areas (P=0.427). CONCLUSIONS The observation of limited diversity of malaria parasites may imply that the use of antigenic markers as genotyping tools for distinguishing recrudescence and re-infections with P. falciparum during drug trials is subjective.

Evaluation of the Possible Mechanisms of Antihypertensive Activity of Loranthus micranthus: An African Mistletoe

Loranthus micranthus (LM), also called African mistletoe is a major Nigerian Loranthaceae plant used traditionally to treat hypertension. The methanolic leaf extract of the plant (LMME) has been shown to elicit anti-hypertensive activity in rats but mechanism remains unclear. This study was undertaken to study the effect of LM on pressor-induced contraction of rat aorta smooth muscles and serum lipid profiles in mice. The LMME was partitioned to produce n-butanol (NBF-LMME), chloroform (CF-LMME), ethyl acetate (EAF-LMME) and water (WF-LMME) fractions. The median effective concentrations and maximum relaxation of the fractions were determined against epinephrine and KCl pre-contracted rat aorta ring model. Serum lipid profiles and nitric oxide (NO) were determined spectrophotometrically in mice administered per orally 250 mg/kg b.w. of each fraction for 21 days. Data were analyzed statistically. NBF-LMME elicited the highest dose-dependent inhibitory effect on rat aorta pre-contracted with norepinephrine and KCl, followed in decreasing order by WF-LMME > CF-LMME > EAF-LMME. Similar order of activity was observed in the ability of these fractions to inhibit elevation in artherogenic lipids, raise serum nitric oxide and reduce cardiac arginase in mice. We conclude the anti-hypertensive activity of L. micranthus involve anti-artherogenic events, vasorelaxation, cardiac arginase reduction and NO elevation.

Serum levels of leptin in Nigerian patients with sickle cell anaemia

BackgroundSeveral studies have shown that the pathophysiology of homozygous sickle cell anaemia (SCA) results in a myriad of metabolic, nutritional, haematological and clinical effects that interact with other co-morbid factors to determine the quality of life and life expectancy of afflicted patients. Because of its critical roles in nutrition and metabolism, inflammation, haematopoiesis and cellular immunity, this study determined the plasma levels of leptin in steady and unsteady states of HbSS in Nigerian patients.MethodsA total of 51 SCA patients aged 5 - 35 years with 34 (61.8%) being females who were either on admission or visiting four medical centres in Lagos, Nigeria together with 22 non-SCD controls aged 5 -30 years comprising 12 (54.5%) females were enrolled after obtaining their informed consent and ethical approval. Patients were further stratified into steady and unsteady cases of SCA based on clinical presentations, while blood samples collected by venipuncture from each of the study participants were analyzed haematologically for full blood count and HbF level and microscopically for malaria, while plasma leptin was assayed using ELISA method. Body composition defined by weight, fat mass and body mass index (BMI) was determined using standard methods. Data obtained for cases and controls were analyzed statistically.ResultsTwenty - one patients had unsteady HbSS and elicited greater and significant (P < 0.05) reduction in fat mass, BMI, HbF and eosinophil count but elevated mean total leukocyte, count, level of irreversibly sickled cells and P. falciparum parasitaemia (4613.7 vs. 749.6 - 1078.4 parasites/uL), pyrexia rate (58.3 vs. 25.8%) when compared with steady state patients or non-SCD controls. Compared to the control, significant decreases in plasma leptin before and after controlling for body fat that was worsened by crisis were observed among the SCD patients. Unlike the non-SCD controls, leptin correlated non-significantly (P > 0.05) with all body composition indices measured in the patients except for fat mass in unsteady cases. Multivariate regression analysis identified ESR and RC as independent predictor of low plasma leptin concentration in the SCA patients.ConclusionsBase on these findings, we conclude that plasma level of leptin is further decreased in the unsteady state of HbSS, shows poor correlation with adiposity and malarial infection but has inflammation and poor reticulocyte response as independent predictors among Nigerian patients.

Occurrence of extended-spectrum and AmpC β-lactamases in multiple drug resistant Salmonella isolates from clinical samples in Lagos, Nigeria

Purpose Salmonella spp. are important foodborne pathogens exhibiting increasing resistance to antimicrobial drugs. Resistance to broad-spectrum β-lactams, mediated by extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase enzymes is fast spreading and has had negative impacts on the clinical outcomes, particularly on third-generation cephalosporins. This study investigated the carriage of AmpC gene among multidrug-resistant Salmonella spp. from Lagos, Nigeria. Methods Forty Salmonella spp. from clinical samples (S. typhi = 13; S. typhimurium = 10; S. enteritidis = 8; S. choleraesuis = 5; S. paratyphi = 4) were subjected to in vitro susceptibility test by disk diffusion methods. Isolates that were resistant to cefoxitin and third-generation cephalosporins were screened for ESBL (Double Disk Synergy Test Method) and AmpC enzyme (AmpC disk test) production. Detection of AmpC fox gene was carried out by polymerase chain reaction. Results Thirty-two (80%) of the Salmonella isolates were cefoxitin resistant. Plasmid-mediated AmpC β-lactamase and ESBL enzymes were recorded in 10/40 (25%) and 16/40 (40%) of the Salmonella isolates, respectively. Specifically, 16/40 (40%) of the Salmonella isolates possessed 380 bp AmpC fox gene, with the highest occurrence found in S. typhi strains (43.8%) followed by S. typhimurium (25%). There was no AmpC fox gene detected in S. paratyphi strains. Interestingly, coproduction of enzymes occurred in some of the isolates, raising fears of resistance to a multitude of antibiotics in the treatment of bacterial infections. Conclusion Emergence of AmpC β-lactamase–producing Salmonella isolates in our environment was recorded for the first time, raising concern on increased antibiotic resistance among strains of Salmonella serovars in Lagos. Further genotypic study of the isolates could answer the questions on strain sources, clonal relatedness, and mechanism of spread.

Reduction in febrile episodes and dynamics of pyrogenic threshold in Nigerian children with Plasmodium falciparum malaria

This study determined the trends of fever in relation to parasitaemia and established Pyrogenic threshold (PYT) for malaria in Nigerian children. Two cross-sectional surveys of malaria and fever were carried out during the dry and rainy seasons of 2007 and 2008 in children aged 6 mo −11 yr attending two Primary Health Care Centres (PHC) in Lagos, Nigeria. Structured questionnaires were used to capture data. A total of 505 children attending PHC during the rainy (n = 385) and dry (n = 116) seasons were studied. Unlike in the dry season, the parasite rate increased with age until 59 mo during the rainy season, while both fever rate (19.7–25.4% vs. 14.1–17.7%) and parasite and fever rate combined (13.4–16.7% vs. 9.2–11.2%) showed a decrease with increasing age. More febrile cases with parasitaemia occurred in children aged 23 mo and below compared to those within the 24–59 mo age bracket during the rainy season only (P

Malnutrition influences tumor necrotic factor-alpha (TNF-α) response among Plasmodium falciparum (Pf) malaria patients in Nigeria

Background In malaria endemic regions, malnutrition has also been reported to be a public health problem. Considering that the pattern of host cytokines-mediated innate immunity is critical in determining malaria outcomes-understanding the impact of malnutrition on innate immune response in Plasmodium falciparum (Pf)-infected patients may be helpful for malaria control. This study aims to determine nutritional status and evaluate the influence of malnutrition on the immune response of infected patients in Lagos, Nigeria.