[show abstract][hide abstract] ABSTRACT: This study aimed at characterizing the phenotypic and toxigenic status of circulating strains of cholera during outbreaks in Nigeria, employing molecular typing techniques. Two hundred and one samples of rectal swabs, stool, vomitus, water (from the well, borehole, sachet, stream, and tap) and disinfectants (sodium hypochlorite) were collected from three states in the country. The samples were inoculated on thiosulphate-citrate bile salt-sucrose (TCBS), Cary-Blair transport medium and smeared on glass slides for direct examination. The Vibrio cholerae isolates were serotyped, biotyped, and characterized using PCR of the cytotoxin gene A (ctxA), wbeO1, and wbfO139 gene primer. Of the 201 samples screened, 96 were positive for V cholerae O1 (48%), with 69 (72%) positive for ctxA gene. The results from this study showed that the circulating strains of cholera in Nigeria were of Ogawa serotype, also observed in other outbreaks in Nigeria (1991, 1992, and 1996). However, the strains were of the Classical biotype and were mainly (72%) ctxA gene-positive. This current investigation has confirmed the production of cholera toxin by the circulating strains, and this could be harnessed for possible cholera vaccine production in Nigeria.
Journal of Health Population and Nutrition 06/2013; 31(2):178-84. · 1.12 Impact Factor
[show abstract][hide abstract] ABSTRACT: This study investigated the levels of prepatent S. haematobium infection in water samples collected from Schistosomiasis haematobium transmission namely: International Institute of Tropical Agriculture (IITA) river and Eleyele river in Oyo state, Oyan dam and Shokori river in Ogun state, Badagry Lagoon and Lagoon (University of Lagos, Lagos state).
Polymerase chain reaction (PCR) assay amplifying the Dra I repeated sequence of S. haematobium cercariae from the water samples was used. Samples of cercariae obtained from a laboratory population of Bulinus globosus and Bulinus rohlfsi snails were assayed following DNA extraction as control. Physico-chemical parameters of the water bodies were determined.
Physico-chemical parameters showed that salinity, conductivity and total dissolved solids were relatively high in the Lagoon front samples (41.91 ppt, 62400.87 micros/cm, 31000.14 mg/L and 7.79), and low in the river samples (13.27 ppt, 1325.67 micros/cm, 11470 mg/L and 8.36 respectively) while pH were similar. PCR showed that 3 out of the 6 water bodies sampled namely IITA river, Eleyele river and Oyan Dam are S. haematobium endemic sites as they gave positive signals.
Three surveyed sites with relatively low salinity namely IITA river, Eleyele river and Oyan dam are high S. haematobium endemic areas and schistosomes survive perhaps best in low salinity environment. PCR could be a more valuable tool in the study of incidence and prevalence of S. haematobium infection compared with conventional cercariae shedding method. On the known strength of focal effects of environmental conditions, implications of these results in the epidemiology and design of control activities are encouraging.
African journal of medicine and medical sciences 12/2012; 41 Suppl:75-80.
[show abstract][hide abstract] ABSTRACT: The 2010 cholera outbreak in northern Nigeria affected over 40,000 people, with a case fatality rate (CFR) of ≥3.75%. We assessed the emergency response of health care workers (HCWs) involved in case management.
This was a cross-sectional study with data collected through a self-administered questionnaire. Data entry and analysis were performed using Epi info software.
A total of 56 HCWs were interviewed. The mean age was 31 years (SD±8.16 years). The majority of the HCWs (80%; n=45) were aged 18-39 years. Most were community health extension workers (60%), and 3.6% (n=2) were medical doctors. Many of the HCWs had less than 2 years of work experience (42%). Additionally, 82% of the respondents had <1 week of cholera emergency response training, and 50% of the HCWs managed >20 suspected cases of cholera per day. Although 78% of HCWs reported the practice of universal safety precautions, 32% (n=18) knew HCWs who developed symptoms of cholera during the epidemic, most of which was believed to be hospital acquired (78%). We also found that 77% (n=43) of HCWs had no access to the required emergency response supplies.
Inadequate training, a lack of qualified HCWs and a limited supply of emergency response kits were reported. Therefore, the government and stakeholders should address the gaps noted to adequately control and prevent future epidemics.
Journal of infection and public health. 10/2012; 5(5):346-53.
[show abstract][hide abstract] ABSTRACT: Food borne Salmonella infection is an important cause of morbidity and mortality. A total of 200 food samples commonly sold in Lagos, Nigeria comprising raw and cooked meat as well as meat products and spoilt meat were analysed for the presence of Salmonella spp using REVEAL serology kit, culture methods employing RPVA (Rappaport Vassiliadis agar), SSA (Salmonella-Shigella agar) and BSA (brilliant sulphite agar) and PCR method for direct detection from samples using primer salm3/4 and ST11/ST15 sets. Using the REVEAL serology kit, 74% of the samples were positive for Salmonella spp, while culture methods showed only 19% to be Salmonella spp. The PCR method revealed that Salmonella spp was present in 62% and 54% of the samples using primer set salm3/4 and ST11/ST15, respectively. However, the primer set ST11/ST15 was more reliable in the identification of Salmonella spp directly from food samples. These tools should prove useful in the continuous monitoring and control strategies especially for ready-to-eat foods, as well as in retail meat outlets, slaughter houses, fast food restaurants for the prevention and reduction of this pathogen that is of significant importance in the food industry.
The Southeast Asian journal of tropical medicine and public health 05/2012; 43(3):718-23. · 0.61 Impact Factor
[show abstract][hide abstract] ABSTRACT: The study was aimed at comparing PCR methods of direct detection from biopsy using the boiling method and one other method with two known gold standards (histology and CLO test) for the diagnosis of H. pylori in Nigeria. A total of 168 biopsies (three from antrum and one from corpus each) were taken from 42 patients presenting with various gastroduodenal symptons after informed consent was obtained from them.The biopsies were analysed using the CLO test kit and histology, while the boiling method as described by Holmes and Quigley (1981) was used to obtain DNA and then PCR using the 16S rRNA gene, glmM gene and cagA gene. With CLO test 15/42 (35.71%) were positive, histology 13/42 (30.95%) were positive, 16S rRNA 22/42 (52.38%) were positive, glmM 19/42 (45.24%) were positive, cagA 19/42 (45.24%) were positive. The sensitivity and specificity of the PCR tests with CLO as the gold standard showed that the tests were 100% sensitive and varied between 74.1% to 84.1% in specificity. The PPV and NPV showed that the NPV was almost 100%, while the PPV was between 68.2% and 75%. Using the histology as the gold standard, the sensitivity was almost 100% while the specificity, the PPV were reduced in comparison to the CLO test. The PCR test using the glmM gene appears to be the most reliable test for diagnosis of H. pylori in Nigeria most especially where culture is difficult due to the power outages.
International Journal of Molecular Epidemiology and Genetics 01/2011; 2(2):178-84.
[show abstract][hide abstract] ABSTRACT: There is an urgent need for affordable point-of-care diagnostics for the differentiation of febrile illnesses and the confirmation of typhoid in endemic countries.
Blood samples were collected from febrile patients with clinical suspicion of typhoid and screened for typhoid fever using the Widal and Typhi Dri Dot tests, while stool and blood samples were screened for Salmonella Typhi using the culture method as well as PCR as a confirmatory test.
A high proportion of febrile patients from Lagos with clinical suspicion of typhoid fever reacted positively in a simple and rapid latex agglutination assay for typhoid fever, indicating that this illness is a common and presumably under-diagnosed health problem in this metropolis. Seropositivity was 19.2% in the rapid test compared with 22.9% in the classical Widal test. The confirmation of typhoid in these seropositive patients appeared cumbersome because of negative blood cultures and low DNA yield in molecular testing. A review of the literature revealed that in Nigeria seroprevalence rates can be high in the normal population and that pathogens other than S. Typhi are often isolated from the blood of seropositive febrile patients.
The simplicity and the relatively high specificity (97.8%) of the rapid test as determined in a study performed in Indonesia calls for a further validation of this promising test for use in Africa.
The Journal of Infection in Developing Countries 01/2011; 5(7):520-6. · 1.00 Impact Factor
[show abstract][hide abstract] ABSTRACT: Problem statement: Crude oil which may be broadly characterized as paraffinic or naphthenic is a complex mixture of alkanes, cycloalkanes and aromatic hydrocarbons. About 500,000 workers are employed in crude oil exploration and production worldwide. There have been reports of occupational exposure during drilling, pumping and transportation of crude oil, including maintenance of equipment used for these processes. Thus, skin tumors have been reported in mice after repeated application of the east Wilmington crude oil to their skin. Approach: It may thus be necessary to investigate the mutagenic potentials of crude oil fractions using a modified Ames test and internationally accepted Allium cepa (Linn) assay. The Allium cepa assay was done to determine the mean root length, mitotic index and chromosomal aberrations of the onions root grown in various concentrations of 5, 10 and 15% v / v crude oil, petrol, kerosene, engine oil and diesel in water. The modified Ames test which is a modification of the standard Ames test was done using E. coli (0157: H7) that has the phenotypic characteristics of glucose and lactose fermentation, motile, urease negative, indole positive and citrate negative. Thus the alteration in normal biochemical characteristics was determined by inoculating the revertant strains produced by the organism after incubating with the crude oil fractions into the specified media to re-determine their biochemical characteristics. Results: The results obtained from the Allium cepa assay showed increasing root growth inhibition with increased concentration and decreasing mitotic index with increased concentration. Stickiness, Vagrant, Bridges and fragments, Bi-nuclei, C-mitosis, multi polar anaphase and anaphase with laggards chromosomal aberration were observed. The modified Ames test showed a remarkable alteration in the biochemical characteristics of E. coli (0157: H7) by petrol and engine oil indicating mutagenicity. Conclusion: The results of the Ames test showed petrol and engine oil to demonstrate mutagenicity in bacteria, while, the Allium cepa assay showed mitodepressive effects of crude oil, petrol, engine oil, diesel and kerosene.
[show abstract][hide abstract] ABSTRACT: Microorganisms are transferred to everyday objects from the environment and infected individuals. Pathogenic microbes are transmissible from the air, skin, hands and other interpersonal contacts and cause diseases most of the time. This study centres on the microbial assessment of telephone receivers, their ability to transfer bacterial infections and the isolation of these microorganisms from receivers, with an emphasis on Staphylococcus aureus and its antibiotic susceptibility pattern.
1,591 isolates were obtained from roadside telephone booths in 16 different locations in the Lagos metropolis. They were all characterised using the Cowan and Steel's manual, after which the antimicrobial susceptibility pattern of the most frequently-occurring isolate was determined.
Of all the locations, Oshodi was found to have the largest number of microorganisms, with Akoka having the least. The organisms were Providencia, Klebsiella, Citrobacter, Enterobacter, Proteus, Escherichia, Staphylococcus, Bacillus, Streptococcus, Micrococcus and yeast. Staphylococcus spp. was the most frequently occurring, making up 20.2 percent of the total number of isolated organisms, followed by Bacillus (18 percent), while Enterobacter and Citrobacter were the least common. 44 percent of the total Staphylococcus screened for an antimicrobial susceptibility pattern showed high resistance to most of the antibiotics used.
This result could be related to the emergence of Staphylococcus-resistant strains, especially in a highly-populated area where there are health and hygiene problems and where drugs are abused. Precautions should be taken to prevent the spread of infectious diseases through the use of public telephones.
Singapore medical journal 03/2009; 50(2):208-11. · 0.63 Impact Factor
[show abstract][hide abstract] ABSTRACT: Antimicrobial susceptibility of Shigella spp. and Escherichia coli, isolated from diarrhoeal patients in Lagos, was studied from March 1999 to February 2000. Four hundred fifty-nine isolates were identified as shigellae (62) and E. coli (397). Shigella flexneri, S. dysenteriae, S. boydii, and S. sonnei accounted, respectively, for 51.6%, 17.7%, 17.7%, and 13% of the total number of shigellae isolated. Eleven cases of shigellosis occurred in the age group of 0-9 years, 22 cases in the age group of 10-19 years, and 29 cases in the age group of > or = 20 years. Of the 397 E. coli isolates, 11 were enteropathogenic E. coli (EPEC), and 7 of these strains were isolated with shigellae from stools of patients aged 0-9 year(s) (71.4%) and 10-19 years (28.6%). Over 70% of the Shigella isolates were resistant to two or more drugs, including ampicillin and tetracycline. Twenty-one distinct multidrug resistance patterns were observed in these isolates. During 1990-2000, resistance to ampicillin increased from 70% to 90%, co-trimoxazole from 77% to 85%, chloramphenicol from 71% to 77%, streptomycin from 71% to 79%, and nalidixic acid from 0% to 11.3%. Resistance to tetracycline decreased from 89% to 79% but with MIC50 and MIC90 values outside the susceptible range. While resistance to ciprofloxacin and ofloxacin remained nil with MIC50 and MIC90 values of 0.008 and 0.0016 microgram/mL respectively. The results of this study revealed the endemicity of shigellosis with S. flexneri as the predominant serogroup in Lagos. Children and young adults were at a higher risk of severe shigellosis. The results also suggest that ampicillin, tetracycline, co-trimoxazole, and streptomycin should not be used as the first-line drugs in the treatment of shigellosis. Nalidixic acid should still be selectively used for treatment, while ciprofloxacin and ofloxacin can be ideal alternatives.
Journal of Health Population and Nutrition 10/2001; 19(3):183-90. · 1.12 Impact Factor
[show abstract][hide abstract] ABSTRACT: Nosocomial infections caused by methicillin-resistant strains of Staphylococcus aureus constitute significant epidemiologic problems. Defining an outbreak requires the use of rapid and highly discriminatory epidemiologic methods to determine the epidemic strains involved in such outbreak.
A descriptive laboratory based surveillance study for MRSA was undertaken. One hundred and forty seven Staphylococcus aureus isolates from clinical specimens were screened for methicillin resistance at the University of Ilorin Teaching Hospital between January and December 2001. Fifty one (34.7%) methicillin resistant strains recovered were epidemiologically characterized using Eco R1 restriction enzyme analysis of their plasmid DNAs.
Forty five (88.2%) MRSA isolates were associated with infections and 6 (11.8 %) were colonizing strains; 36 (70.6%) and 15 (29.4%) were hospital and community acquired respectively. Skin and soft tissues were sites of infection in 36 (70.6 %) cases and surgical, emergency and ICU accounted for 33 (64.7%) isolates. All isolates were resistant to more than two antibiotics but sensitive to vancomycin. Forty two (82.4 %) isolates contained plasmids including 9 (21.4 %) that contained more than one plasmid. Restriction Enzyme Analysis of the Plasmid DNA (REAP) divided the isolates into 9 Eco R1 profiles, with profile 2 accounting for 41.7% of all nosocomial infections in the wards, implying that it is endemic. The remaining nosocomial profiles occurred less frequently, suggesting that they are sporadic strains originating from outside the hospital. The community strains showed diverse digestion pattern indicating that they are from different clones.
The spread of MRSA can be controlled through reinforcement of appropriate use of antibiotics, hand washing and laboratory surveillance for MRSA, particularly in the surgical wards and intensive care units, in order to identify sources of outbreaks.