Evaluation of IgG antibodies against Respiratory Syncytial Virus (RSV), and associated risk factors for severe respiratory tract infections in pre- school children in North-central, Nigeria

Background: Childhood mortality and morbidity due to RSV is increasing. Our current study was aimed at determining the sero-prevalence rate of RSV IgG antibodies and investigates certain known risk factors for RSV  disease severity in infants and pre-school children presenting with various forms of respiratory tract infections in Ilorin, Nigeria.Materials and Methods: About 280, children and 30, aged matched controls were enrolled into the study at the specialist hospital Ilorin. Blood testing for anti RSV IgG was done using a commercial ELISA kit by IVD Research Inc® Carlsbad. California U.S.A. Information regarding Nutritional status, socio-economic status and other demographic variables were collected.Results: A prevalence rate of 85.7% was recorded among tested children and 23.3%, in controls, across age groups and gender. A statistically significant difference in age groups were recorded among patients with  LRTI, (p <0.05), age <1 41%, age 1 <5, 27.6%. This was also the case forchildren with SRTI (Pneumonia and Bronchiolitis), with age < 1yr, 9%, and 1 <5yr, 19.8%. Analysed risk factors for disease severity showed thatnutritional status of children were statistically significant for disease severity, p-value, 0.039 (Chi square test).Conclusions: We report a high level of exposure to RSV in infancy and early childhood among children from a representative population in a major central Nigerian City, further studies into neutralising antibody levels and subtype distribution of RSV are advocated.Key Words: RSV, Respiratory tract infection, Seroprevalence, Ilorin

Cluster analysis and geospatial mapping of antibiotic resistant Escherichia coli O157 in southwest Nigerian communities

serotypes causing severe complications leading to high intestinal morbidity and occasional mortality in several communities in southwest Nigeria, were evaluated. Biotyped Escherichia coli strains (n = 508) from subjects with diarrhea and related intestinal infections, various domestic water sources and food animal products were evaluated for antibiotic resistance relatedness, conjugative activity, virulence factor and biofilm production. Antibiotic resistance of Escherichia coli O157 encoded with stx was mapped for geospatial spread. Detected stx-encoded Escherichia coli O157 (7.56%) of human strains were significantly higher compared to water and food animal strains (p = 0.001) with high conjugative and transformative activity (OR(95%CI) = 34.65(94.5); p = 0.023). Water- Escherichia coli O157 reveal significant median resistance to ciprofloxacin, gentamycin (p 60% resistance to doxycycline (MIC50 8 μg/mL and MIC90 128 μg/mL; p = 0.018), tetracycline (MIC50 4 μg/mL and MIC90 64 μg/mL), ciprofloxacin (MIC50 2 μg/ mL and MIC90 128 μg/mL) and gentamycin (MIC50 4 μg/mL and MIC90 256 μg/mL). Strains from human diarrhea, UTI, colitis, cattle, fish, sheep, ground waters, streams, and rivers characterized with biofilm, hemolysin, protease productions, R-plasmid (≈14.30kbp) and MARI (0.84) were highly related. Principal component analysis (score plot) revealed a significant association between resistant human diarrheic strains with cattle and poultry strains. A high population of heterogeneous stx-encoded diarrheagenic and colitis strains was predominant in urban settings spreading with food animal and water Escherichia coli O157 strains. Human diarrheagenic Escherichia coli O157 were highly related to antibiotic resistance and virulence pattern with water and animal products strains. Strategic interventions through the implementation of One Health approach and population-target antimicrobial stewardship are needed to mitigate the increasing intestinal morbidity and reduction of mortality impact. Regular application of spatial data on clonal dissemination is important for monitoring, surveillance of antimicrobial resistance and transmission of zoonotic food-borne Escherichia coli O157 pathogens

Suitability of spectrophotometric assay for determination of honey microbial inhibition

Commonly used methods for determination of antibacterial potency of honey are usually the disc, agar well diffusion and dilution plate assay which had shown various demerit of inaccuracies and impreciseness. Therefore, the suitability of spectrophotometric assay for determination of honey inhibitory activity is evaluated in this study. Honeys from different sources in southwest states in Nigeria were assayed for antibacterial activity using 96-well micro-titre plate spectrophotometric methods to determine the minimum inhibitory concentration (MIC) against enteric bacteria strains. The honey inhibition assay of Nigerian honeys tested against enteric bacilli showed more than 90% inhibitory activity. Among all the honeys sample assayed, only two honeys reveal a very low MIC of 31.25 and 125mg/mL. The use of spectrophotometry is a precise method to determine honey inhibitory rate and it is proven to be suitable highly sensitive, reproducible, specific, reduced cost, fewer amounts of sample and reagent are require

Detection and Seroprevalence of Hiv 1 & 2 Antibodies in Abeokuta, Southwest, Nigeria

Abstract The HIV pandemic has ravaged mankind for over 3 decades. Gradually, incidence of new infections has declined globally due to increased prevention and control measures. In Southwestern Nigeria, there has been increased surveillance activ ity to complement control measures in recent years. We report here findings of the latest HIV surveillance revealing the p revalence of HIV in Abeokuta, Nigeria. About 744 subjects were tested for HIV seroconversion between January and March 2010. Screening tests were carried out using Determine™ HIV 1 & 2 (Abbott) and Chembio HIV 1& 2 Stat-Pak™ rapid test kits following manufacturer's instructions. A seroprevalence rate of 11.7% (87/744) was determined with a significantly higher seropositivity in females (16.0%; 60/ 375) than males (7.3%; 27/ 369). Age group 16-45 years old was found to have the highest seroprevalence rate of 13.6% (70/514), followed by the age group 46 years and older with 11.0% incidence (12/109), and lastly, the age group 1-15 years old had the lowest HIV seroprevalence of 4.1%(5/ 121). HIV prevalence in outpatient was the highest, (12.5%; 33/264). This was followed by OPD having 15.0 (9/60), inpatient (Ward) subjects who had 11.0% seroprevalence (22/ 199) and others having 8.3% seroprevalence (14/ 168). The lo west HIV seroprevalence was recorded in Outreach visitations with only 2 positive cases (3.8% seroprevalence; 2/53). This current report shows a fairly high HIV seroprevalence rate in Southwestern Nigeria, with relatively high rate of HIV infections among the elderly. According to these findings prevention and control measures should thereby be stepped up, particularly at the local level with mo re attention toward sexually active adults and the elderly

Review

Circulating vaccine-derived poliovirus and its implications for polio surveillance and eradication in Nigeria: A review of the literatur

Evolution and genetic diversity of SARS-CoV-2 in Africa using whole genome sequences

Background The ongoing SARS-CoV-2 pandemic was introduced into Africa on 14th February 2020 and has rapidly spread across the continent causing a severe public health crisis and mortality. We investigated the genetic diversity and evolution of this virus during the early outbreak months, between 14th February to 24th April 2020, using whole genome sequences. Methods We performed recombination analysis against closely related CoV strains, Bayesian time scaled phylogeny, and investigation of spike protein amino acid mutations. Results Recombination signals were observed between the Afr-SARS-CoV-2 sequences and reference sequences within the RdRPs and S genes. The evolutionary rate of the Afr-SARS-CoV-2 was 4.133 × 10−4 Highest Posterior Density (HPD 4.132 × 10−4 to 4.134 × 10−4) substitutions/site/year. The time to most recent common ancestor (TMRCA) of the African strains was December 7th 2019, (95% HPD November 12th 2019-December 29th 2019). The Afr-SARCoV-2 sequences diversified into two lineages A and B, with B being more diverse with multiple sub-lineages confirmed by both maximum clade credibility (MCC) tree and PANGOLIN software. There was a high prevalence of the D614G spike protein amino acid mutation 59/69 (82.61%) among the African strains. Conclusion This study has revealed a rapidly diversifying viral population with the G614G spike protein variant dominatinge advocate for up scaling NGS sequencing platforms across Africa to enhance surveillance and aid control effort of SARS-CoV-2 in Africa