Neuroprotective potential of plant derived parenchymal stem cells extract on environmental and genetic models of Parkinson disease through attenuation of oxidative stress and neuroinflammation.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by both motor and non-motor features. The current treatment regimen for PD are dopamine enhancers which have been reported to worsen the disease prognosis after long term treatment, thus, the need for better treatment options. This study sought to investigate the protective action of Double Stem Cell® (DSC), a blend of stem cells extracts from Swiss apples (Malus Domestica) and Burgundy grapes (Vitis vinifera) on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinsonism in mice and genetic model of PD in Drosophila melanogaster. Male albino mice were pretreated with MPTP (4 × 20 mg/kg, i.p., two hourly in 8 h), twelve hours before administration of DSC (8, 40, or 200 mg/kg, p.o.). Thereafter, behavioural, biochemical and immunohistochemical assays were carried out. The impact of vehicle or DSC supplementation on α-synuclein aggregation was evaluated in Drosophila melanogaster using the UAS-Gal4 system, female DDC-Gal4 flies were crossed with male UAS-α-synuclein, the progenies were examined for fecundity, locomotion, memory, and lifespan. MPTP-induced motor deficits in open field test (OFT), working memory impairment (Y-maze test (YMT)) and muscle incoordination (rotarod test) were ameliorated by DSC (8, 40 or 200 mg/kg) through dose-dependent and significant improvements in motor, cognitive and motor coordination. Moreso, MPTP exposure caused significant increase in lipid peroxidation and decrease in antioxidant enzymes activities (glutathione, catalase and superoxide dismutase) in the midbrain which were attenuated by DSC. MPTP-induced expression of microglia (iba-1), astrocytes (glia fibrillary acidic protein; GFAP) as well as degeneration of dopamine neurons (tyrosine hydroxylase positive neurons) in the substantia nigra (SN) were reversed by DSC. Supplementation of flies feed with graded concentration of DSC (0.8, 4 or 20 mg/ml) did not affect fecundity but improved climbing activity and lifespan. Findings from this study showed that Double Stem Cell improved motor and cognitive functions in both mice and Drosophila through attenuation of neurotoxin-induced oxidative stress and neuroinflammation.

Ivermectin shows clinical benefits in mild to moderate COVID19: a randomized controlled double-blind, dose-response study in Lagos.

INTRODUCTION: In vitro studies have shown the efficacy of Ivermectin (IV) to inhibit the SARS-CoV-2 viral replication, but questions remained as to in-vivo applications. We set out to explore the efficacy and safety of Ivermectin in persons infected with COVID19. METHODS: We conducted a translational proof of concept randomized, double blind placebo controlled, dose response and parallel group study of IV efficacy in RT-polymerase chain reaction proven COVID 19 positive patients. Sixty-two patients were randomized to three treatment groups. (A) IV 6 mg regime, (B) IV 12 mg regime (given Q84 h for 2 weeks) (C, control) Lopinavir/Ritonavir. All groups plus standard of Care. RESULTS: The Days to COVID negativity (DTN) was significantly and dose dependently reduced by IV (P = 0.0066). The DTN for Control were, = 9.1+/-5.2, for A 6.0 +/- 2.9 and for B 4.6 +/-3.2. Two way repeated measures ANOVA of ranked COVID 19 +/- scores at 0, 84, 168 and252h showed a significant IV treatment effect (P = 0.035) and time effect (P < 0.0001). IV also tended to increase SPO2% compared to controls, P = 0.073, 95% CI-0.39 to 2.59 and increased platelet count compared to C (P = 0.037) 95%CI 5.55-162.55 × 103/ml. The platelet count increase was inversely correlated to DTN (r = -0.52, P = 0.005). No SAE was reported. CONCLUSIONS: 12mg IV regime given twice a week may have superior efficacy over 6mg IV given twice a week, and certainly over the non IV arm of the study. IV should be considered for use in clinical management of SARS-COV2, and may find applications in prophylaxis in high risk areas.

The West African ebola virus disease epidemic 2014-2015: A commissioned review.

The first epidemic of Ebola haemorrhagic disease in West Africa is the largest and longest Ebola epidemic till date, where the outbreak notably involved three countries with distant spread to other countries. It has caused significant mortality, with reported case fatality rates of up to 70%. Data and relevant information were extracted from the review of majorly relevant publications/papers about the Ebola epidemic in West Africa and other previous outbreaks of Ebola virus (EBOV). As of 2016, with the epidemic under control, the World Health Organization has warned that flare-ups of the disease are likely to continue for some time as recently occurred in Sierra Leone and the on-going in Guinea. As this may not be the last outbreak of Ebola virus disease (EVD) in West Africa, there is a need to focus on diagnostic and research capacity required to curtail EVD with adequate measures for emergency preparedness and policies for innovative treatment strategies.

Seroprevalence of hepatitis B virus infection among pregnant women at the antenatal booking clinic of a Tertiary Hospital in Lagos Nigeria.

OBJECTIVES: The objectives were to determine the seroprevalence of hepatitis B virus (HBV) infection and assess the major risk factors among Nigerian pregnant women. SUBJECTS AND METHODS: This was a cross-sectional descriptive study carried out among pregnant women at the antenatal clinic of a Tertiary Hospital in Lagos, Nigeria. A total number of 150 consenting pregnant women were selected for the study. A structured pretested interviewer-administered questionnaire was used for the data collection. Sera were collected and tested for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg). RESULTS: Of the 150 women screened during the study, 11 (7.3%) were seropositive for HBsAg. Of these 11 women, 4 (36.4%) were also positive for HBeAg. There was no statistically significant difference in the mean ages of participants who were seropositive for HBsAg and those who were negative for the virus (P=0.888). There were statistically significant differences in the seroprevalence of HBsAg recorded among respondents with previous surgery (odd ratio [OR]-2.97; 95% confidence interval [CI]-1.08-16.67; P=0.046), previously affected sibling or spouse (OR-5.03; 95% CI-1.11-25.27; P=0.001) and those with two or more lifetime sexual partners (OR-4.11; 95% CI-2.85-9.22; P=0.024). CONCLUSION: The sero-prevalence rate of HBV infection and also its infectivity is high in Lagos, Nigeria. These findings thus support the need for a nationwide policy of routine and widespread HBV screening among pregnant women.

Hepatoprotective and antioxidant activities of Hepacare®, a herbal formulation against carbon tetrachloride-induced liver injury.

BACKGROUND: Hepacare(®) is a herbal formulation used to treat patients with sickle-cell anaemia complicated with jaundice, also recommended as a protective agent against liver damage due to chronic ingestion of alcohol. METHODS: In vitro antioxidant properties of Hepacare(®) was determined using 1, 1- diphenyl-2-picryl-hydrazyl (DPPH), total antioxidant capacity, reducing power ability, and nitric oxide assays. Hepatoprotective effect of Hepacare(®) (50-400 mg/kg/day for 7 days, p.o.) was investigated in male Sprague Dawley rats against carbon tetrachloride (CCl(4) /olive oil, 1:1, 0.7 ml/kg, i.p.)-induced liver damage. At the end of the study, blood samples and liver tissue were assayed for biochemical and antioxidants parameters. RESULTS: Hepacare produced concentration dependent inhibition of DPPH and nitric oxide activity with IC(50) of 48.50 and 55.00 µg/ml, respectively, it suppressed the absorbance of ABTS(.+) with total antioxidant capacity of 423.47±8.37 mg QUE/g. CCl(4) administration induced significant (P<0.001) elevation of serum aspartate transaminase (1.70 fold), alanine transaminase (1.60 fold), alkaline phosphatase (2.90 fold) and bilirubin (2.00 fold) in comparison to control. The increase in serum biomarker were dose-depen-dently reversed by Hepacare(®) pretreatment. More-over, CCl(4) pretreatment increased (P<0.001) malondialdehyde (MDA) (73.98%) and decreased (P<0.001) antioxidant enzymes level but Hepacare pretreatment produced dose-dependent attenuation of the increased MDA (3.84 fold) with enhancement of glutathione (3.08 fold), superoxide dismutase (2.08 fold), and catalase (3.14 folds) levels in comparison to CCl(4) treated group, similar to those of silymarin reference standard. CONCLUSION: Hepacare was beneficial in the prevention of CCl(4)-induced hepatocellular injury, possibly by scavenging reactive free radicals, and boosting endogenous antioxidant systems.

Detection of avian influenza virus from fecal samples of poultry birds in Lagos State.

BACKGROUND: Although there have been a lot of research done on Avian Influenza in the world, there are still visible indications in the Nigerian poultry farming system that the bio-security measures are not adhered to strictly. Hence, it is of great importance to identify the circulating strains of Avian Influenza virus in Nigeria, so as to prevent and control another outbreak of the disease. METHODS: Between May and June 2011, 184 stool samples were collected from seemingly healthy poultry birds in Ikorodu and Ejigbo, within Lagos state. RNA extraction using diatomaceous sand method and Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) was carried out on all samples. FINDINGS: Influenza virus type A 25(13.6%) was detected from poultry B (Ejigbo poultry), while there was no positive sample from poultry A (Ikorodu Poultry), the positive samples were further sub-typed, and H1 [1(4%)] was detected. Altogether, 159 (86%) of the fecal samples collected gave a. negative result for Influenza A, and also, 24(96%) out the 25 samples positive for Influenza A gave tested negative when subtyped with H1 and H3. INTERPRETATION: Results of the samples gotten from both poultries corroboratethe effect of poor bio-security practicesin the spread of Influenza A viruses and that some poultries in Nigeria are not adhering to proper farm bio-security practices. Also the identification of H1 subtype which is human adapted is indicative of a re- emerging potential threat to public health.

Seroprevalence of other antibodies (herpes, CMV, rubella, varicella, hepatitis B and C, syphilis, chlamydia, mumps, toxoplasmosis) in HIV-positive patients.

We attempted to determine the seropositivity of HIV-positive patients to other antibodies (herpes, CMV, rubella, varicella, hepatitis B, hepatitis C, syphilis, chlamydia, mumps, toxoplasmosis). The study was carried out at the Prenatal Diagnosis and Therapy Centre of a Tertiary Hospital in Lagos, Nigeria. A total of 70 patients (50 females and 20 males) attending the centre between June 1997 and December 2005 who were screened and found to be HIV-seropositive were further screened for herpes simplex IgG/IgM, CMV IgG/IgM, rubella IgG/IgM, varicella IgG/IgM, mumps IgG/IgM, toxoplasmosis IgG/IgM, chlamydia IgG/IgM, hepatitis B and hepatitis C IgG/IgM using ELISA kits and syphilis (THPA) using the HAE method. Our study showed that a large number of HIV-positive patients are carriers of other antibodies and should be screened for them before therapy.

Early-onset sensorineural hearing loss in Lassa fever.

Lassa fever (LF) is a viral hemorrhagic disease which affects one-fourth to two million people annually with the fatality rate of about 10,000. It is associated with sensorineural hearing loss (SNHL) usually at the convalescent stage. Recently, cases of SNHL at the acute phase have been reported. This study was done to further investigate the incidence and features of SNHL in acute phase of LF. It is a prospective case-control study of LF patients seen with acute SNHL conducted between July 2007 and April 2009 at Irrua Specialist Teaching Hospital Nigeria. The diagnosis of acute LF was based on the clinical features and detection of IgM antibodies and/or positive Lassa virus-specific reverse transcriptase-polymerase chain reaction using primers S36+ and LVS 339 while SNHL was diagnosed clinically and confirmed with PTA and speech discrimination tests. Patients with other acute febrile illnesses were used as control. Statistical analysis was done using SPSS version 11 and Fisher's exact test while level of significance was set at p < 0.05. Out of the 37 confirmed cases of LF, 5 (13.5%) and none (0%) of the control developed early-onset SNHL (p = 0.03). Forty percent of the cases studied had negative IgM. The audiograms showed involvement at all frequency groups with pure tone average 65-85 dB and the speech discrimination 20-40%. The overall case fatality rate was 27.0%, and for early SNHL cases 60.0% (p > 0.05). The incidence of SNHL in LF infection is about 13.5% and could be a reflection of a worse disease process. There is possibility of direct viral invasion aside immunological reaction as a causative mechanism.

Efficacy of HIV PCR techniques to diagnose HIV in infants born to HIV infected mothers at LASUTH.

BACKGROUND: There has been so many difficulties encountered in the diagnosis of HIV infection in infants < 18 months of age born to HIV-infected mother. In these infants, definitive diagnosis can only be carried out by antigen based techniques which are expensive and not widely available in developing countries. OBJECTIVE: To generate information on the rate of mother to child transmission in Nigeria and to compare the efficacies of both the HIV-1 RNA and HIV-1 DNA PCR techniques in the diagnosis of this infections in infants. METHOD: Ninety (90) whole blood samples were obtained from 45 HIV positive mothers and 45 infants born to these mothers from the Department of Obstetrics and Gynaecology, Lagos State University Teaching Hospital (LASUTH), Ikeja, Lagos. The presence of HIV was determined using the Amplicor HIV-1 DNA test and an in-house RNA PCR method. RESULTS: All the infants were HIV antibody positive, however, only 5 infants were positive by HIV-1 DNA PCR, indicating an 11% rate of transmission from HIV positive mothers. Among the 5 infants positive by the DNA PCR, only 4 were positive for the in-house RNA PCR. CONCLUSION: The 11% transmission rate recorded in this study was similar to that from mothers' who had Nevirapine ART interventions and both the HIV-1 DNA test and the in-house RNA PCR tests were sensitive and specific in the diagnosis of infection in infants, depending on the level/ state of HIV infection in infants.

Prenatal diagnoses of cytomegalovirus (CMV), rubella, toxoplasmosis, varicella, parvovirus, herpes simplex and syphilis. the Lagos programme experience.

Prenatal diagnosis of infectious diseases has been shown to be indispensable to confirm or exclude in utero infections due to cytomegalovirus, rubella, toxoplasmosis, varicella, parvovirus and herpes simplex, and a multidisciplinary approach is needed. Our report is on data obtained from 236 pregnant women at risk for the above-mentioned conditions. The specific IgM test suggested seroconversion in only 198 of these patients and 162 of them requested prenatal diagnoses by means of fetal blood sampling or amniocentesis, or both. The results are encouraging but more work is required to optimize our diagnostic approach, i.e., monoclonal antibodies and DNA probes with direct identification by means of choronic villi sampling, which we use for prenatal diagnoses of hemoglobinopathy (DNA-genetic).

Interferon-gamma in suppurative otitis media: significance of otorrhoea type and disease outcome.

BACKGROUND: Interferon-gamma has been reported to have an immunoregulatory role in otitis media with effusion. However, such a role remains to be determined in acute suppurative otitis media. AIM: To determine the levels of interferon-gamma in middle-ear secretion in children with acute suppurative otitis media, and to determine the significance of interferon-gamma to the nature of otorrhoea and the outcome of otitis media. SETTINGS AND DESIGN: Prospective, longitudinal follow up of patients selected from community and tertiary health centres. METHODS: We selected children with acute suppurative otitis media, diagnosed as otorrhoea of less than three months' duration. Middle-ear secretions were collected by pipetting and stored at -80 degrees C. Interferon-gamma was assayed using enzyme-linked immunosorbent assay. The patients were treated and followed up for nine to 12 months, to separate those with resolved acute suppurative otitis media from those with chronic suppurative otitis media. RESULT: The study initially included 358 cases of acute suppurative otitis media. Nine-month follow up was achieved in 304 patients (85 percent). Of these patients, acute suppurative otitis media resolved in 187 (61 percent), while chronic suppurative otitis media was evident in 117 (39 percent). The children with completed follow up comprised 173 boys and 131 girls, aged between four months and nine years (mean age 6.6 years; standard deviation 1.32). These children had purulent otorrhoea in 171 cases (56 percent) and mucoid otorrhoea in 133 cases (44 percent). The children's middle-ear secretion interferon-gamma concentrations ranged from 12 to 126 pg/ml. The mean middle-ear secretion interferon-gamma concentration was 27.2 pg/ml (standard deviation 8.8) in patients whose acute suppurative otitis media resolved, and 73.1 pg/ml (standard deviation 9.5) in those progressing to chronic suppurative otitis media. In children with purulent otitis media, the mean middle-ear secretion interferon-gamma concentration was 43.5 pg/ml (standard deviation 15.6); in those with mucoid otitis media, it was 74.3 pg/ml (standard deviation 19.1). Univariate analysis revealed significant differences in middle-ear secretion interferon-gamma concentration, comparing resolved acute suppurative otitis media and chronic suppurative otitis media cases (p = 0.00), and comparing purulent and mucoid otitis media cases (p = 0.00). Pearson correlation testing revealed significant inverse correlation between interferon-gamma concentration and middle-ear secretion immunoglobulin G concentration (p = 0.01), immunoglobulin E concentration (p = 0.03) and immunoglobulin A concentration (p = 0.00). CONCLUSION: A high concentration of interferon-gamma in middle-ear secretions promotes chronicity of suppurative otitis media. Further research in this area may lead to the development of agents which assist the control of suppurative otitis media chronicity.

Prevalence of rotavirus-induced diarrhea among children under 5 years in Ilorin, Nigeria.

Diarrhoea disease is an important cause of morbidity and mortality in Nigerian children and rotavirus has been identified as an important causative agent among children below 5 years. We determined the prevalence of rotavirus-induced diarrhoea among under-5 s by electrophenotyping. Stool samples were collected from eligible subjects who presented with acute diarrhoea. The samples were processed for viral studies by electrophenotyping. Among the 299 subjects recruited, 55.9% were positive for rotavirus. Eighty percent of the recruited patients were below 24 months. There was a significant decrease (p-value = 0.00001) in the prevalence of rotavirus among diarrhoea patients above the age of 24 months when compared with those below this age group. Rotavirus was associated with higher morbidity and mortality. We conclude that rotavirus is the most important cause of diarrhoea among children <5 years in Ilorin, Nigeria and its prevalence is highest in the first 2 years of life. Adequate rehydration should be regarded as the mainstay of management.

Viral isolates of intussusception in Nigerian infants.

Idiopathic intussusception is associated with viral pathogens of gastrointestinal respiratory and febrile diseases of infancy and early childhood. These agents are known to vary from one region to another. No such specific viruses have, however, been reported from Nigeria. We therefore collected stools from 28 infants with intussusception as well as 20 age- and sex-matched healthy controls and subjected these specimens to viral isolation techniques. Of the 21 viral isolates obtained from the two groups, 17 (81%) were from the intussusception group while 4 (19%) were from the controls. Ten (58.8%) of the 17 isolates from these subjects were identified as adenoviruses using monoclonal antibody. All of them were from the intussusception group. None of the four isolates from the controls significantly reacted with this antibody. We concluded that adenoviruses are strongly associated with primary intussusception in Nigerian infants.

Diversity of human rotavirus VP6, VP7, and VP4 in Lagos State, Nigeria.

This study investigated the diversity of rotavirus strains recovered from young children in Lagos, Nigeria, during December 1996-January 1997. In total, 287 children, aged 1-60 month(s), presenting with diarrhoea to the Gbaja Health Centre of Massey Street Children Hospital and the Lagos University Teaching Hospital, were included in the study. Rotavirus-positive specimens were characterized by monoclonal antibody enzyme-linked immunosorbent assay (ELISA) for VP6 subgroup and VP7 serotype and by polymerase chain reaction (PCR) for VP4 genotype and VP7 strains (that were non-reactive to ELISA). Of 84 samples tested for VP6 subgroup epitope, subgroup II was predominant (51%) with only a few subgroup I strains (4%), while many could not be typed at all (45%). For the VP7 serotypes, G1 was the most prevalent strain (45%), followed by G3 strains (5%). Neither G2 nor G4 strains were found, although mixed G1/G2 has been reported for the first time in Nigeria. Of strains that were non-reactive to ELISA, 29 (34%) could not be typed by PCR for G type. A subset of 23 samples was selected on the basis of RNA electropherotype, VP7 serotype, and included nine strains of VP7 that were non-reactive to ELISA. VP4 genotype of this subset was determined by PCR, and the most prevalent genotype was P[6] (30%), followed by P[8] (26%). Only one P[4] strain was identified. This study has shown the diversity of rotavirus strains circulating in West Africa.

Viral diarrhoea in young children in two districts in Nigeria.

OBJECTIVES: To determine the prevalence of viral agents of diarrhoea in Ilorin and Lagos, two zones in Nigeria. DESIGN: A survey of young children who had clinically confirmed diarrhoea. SETTING: University of Ilorin Teaching Hospital in Ilorin, Kware State and the Massey Street Children's Hospital in Lagos State, Nigeria. SUBJECTS: 108 children under the age of five. RESULTS: The prevalence rates observed were 33.3% for rotavirus, 6.7% for adenovirus and 1.2% for astrovirus. The rotavirus strains were characterized further. PAGE determined the presence of seven patterns of RNA electropherotypes, with one short RN patterns and six long patterns. The G and P types of selected rotavirus positive samples were characterized by RT-PCR techniques. The VP7 G typing showed that GI was the most prevalent single strain found (8.3%), while G3 and G4 accounted for 6.7% and 1.7%. The rate of mixed G serotypes was 26.7%. The P[6] genotype was the most prevalent (52%) and the P[4] had a prevalence of 8%. The mixed P genotype accounted for 28% of the rotavirus strains. The high rate of mixed infection may have an implication on vaccine development. CONCLUSION: Rotavirus was the most prevalent virus in the study with astrovirus being the second most prevalent. There was only a single incidence of astrovirus.

Measles HI-antibody levels in Lagos children, Nigeria: a follow-up study to resurgence of measles in Lagos metropolis.

A total of 138 children aged between 0-36 months were bled and screened for measles haemagglutination inhibiting (HI)-antibody. Twenty seven children were from age group (0-4) months with 16 (59.3%) seropositive while, 67 and 44 were bled in the group (5-9) and > or = 12 months with 29 (43.3%) and 31 (70.5%) sero positive sera respectively. The distribution of the antibody titre pattern among various age groups suggest vaccination against measles should be at age 9 month. The antibody titres pattern of seroconverted vaccinees also showed that the vaccine administered at our study centre were potent enough to elicit good and protective immune response in vaccinees when given at age 9 month. Our study agrees with the current policy of vaccinating children against measles at age 9 months in Nigeria and should therefore be continued. Based on observations in this study, we suggest; continued administration of the Edmonston-Zagreb strain of measle vaccine currently-in-use in Nigeria, mother's breast-feeding of children for a longer period before the apporpriate age for vaccination, and the possible administration of Vitamin A-a potent immune enhancer, as a supplement during immunization programmes in Nigeria. The introduction of a booster dose of measles vaccine at elementary school age in order to care for the residual unvaccinated children may be a good strategy for measles eradication necessary to be considered in Nigeria and might probably forestall instances of measles outbreaks in children during their second year in school.

Zoonotic infections in Nigeria: overview from a medical perspective.

Infections of domestic and wild animals that are transmitted directly or by an arthropod vector to humans are a major cause of morbidity and mortality worldwide and particularly in Nigeria. With a population of over 100 million and the need for improved health care delivery, Nigerians are at considerable risk considering the seriousness of these infections. Zoonotic infections that are endemic in Nigeria include tuberculosis, trypanosomiasis, toxoplasmosis, taeniasis, rabies, lassa fever and yellow fever. Zoonotic food-borne infections (caused by Campylobacter, Salmonella and Escherichia coli O157:H7) and cryptosporidiosis are emerging. Sporadic cases such as strongyloidiasis, ascariasis, leptospirosis, scabies, pentastomiasis and African histoplasmosis have been reported. There is a need to determine the prevalence of tick-borne zoonoses. Prevention and control of zoonoses in humans is by vaccination, treatment and health education. As a first measure to improve control, the link between veterinary and medical officers, which is presently very weak, needs to be strengthened. Furthermore, regional multidisciplinary approaches to the control of zoonotic infections should be adopted in West Africa, which take into consideration the huge inter-border traffic.

Genotypic and antigenic characterization of hemagglutinin proteins of African measles virus isolates.

A comprehensive phylogenetic study based on the hemagglutinin (H) protein of all known African measles virus (MV) isolates is presented. The study includes 64 new H gene sequences from Ghana. Nigeria and South Africa as well as viruses from Zambia and The Gambia for which only incomplete sequencing data were available and that have previously not been genotyped. The results provide further support to the tentative assignment of the Nigerian and Ghanaian viruses to a new genotype B3 within clade B. A distinct geographic distribution pattern emerged with clade B viruses circulating exclusively in African countries north of the equator. All MV strains from southern Africa grouped in clades A and D with the majority of viruses belonging to genotype D4. The viruses considerably differed by their sensitivity to neutralization by monoclonal antibodies (mAb), but three selected antibodies were sufficient to distinguish between African MVs representing four different genotypes.

Molecular epidemiology of Nigerian and Ghanaian measles virus isolates reveals a genotype circulating widely in western and central Africa.

Sub-Saharan Africa is one of the regions of the globe with the highest measles-related morbidity and mortality. Yet only seven virus isolates from this vast region have been phylogenetically characterized on the basis of their nucleoprotein, the last one in 1991. To characterize the prevalent wild-type viruses and to understand their circulation pattern, a large panel (n = 45) of isolates was collected in Ghana and Nigeria in 1997 and 1998. On the basis of their nucleoprotein sequence, the viruses clearly belong to clade B but a reshuffling of the structure of this clade was proposed, tentatively extending the number of genotypes from two to three on the basis of quantitative criteria. The sequences revealed the co-circulation of at least two distinct viruses in the cities of Lagos and Ibadan, suggesting that the number of susceptible individuals seems to be high enough to support endemic circulation of at least two distinct viruses. The endemic co-circulation of several viruses may well be a characteristic of communities with low vaccination rates. One of these viruses was also found in Accra in 1998 as well as in a 1994 case linked to distant Kenya, suggesting that clade B viruses are prevalent in sub-Saharan Africa while non-B viruses seem to dominate the south of Africa.

Potency status and efficacy of measles vaccine administered in Nigeria: a case study of three EPI centres in Lagos, Nigeria.

The potency status and efficacy of measles vaccines were studied in three immunization (EPI) centres in the suburban area of Lagos, Nigeria. A total of 14 vials of measles vaccine were collected and subjected to potency testing while, 203 measles-vaccinated children were recruited for this study. Only 85 (41.87%) of the vaccinees reported back for the post-vaccination follow-up screening. The seroconversion pattern showed that 51(60%) had potent antibody titres ranging from 1:40 to 1:1280, while the remaining 34 (40%) had a low antibody titres between < 1:20 and 1:20. The vaccine potency test showed that only 1 (7.14%) of the 14 vaccine vials collected at these centres had virus titre of 3.5 Log while the remaining 13 (92.86%) had virus titres lower than 3.0 Log: the recommended human dose by the World Health Organisation (WHO) for measles vaccine. The administration of these subpotent and/or impotent vaccines vis-à-vis the status of immune response elicited in the vaccinees may be one of the reasons for the occurrence of measles infection in vaccinated children in the recent time in Nigeria. We herein suggested the subjection of all vaccines to a thorough standard laboratory screening before use in Nigeria.