Molecular characterization of the circulating strains of Vibrio cholerae during 2010 cholera outbreak in Nigeria.

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.

Cholera epidemiology in Nigeria: an overview.

Cholera is an acute diarrhoeal infection caused by ingestion of food or water contaminated with the bacterium, Vibrio cholera. Choleragenic V. cholera O1 and O139 are the only causative agents of the disease. The two most distinguishing epidemiologic features of the disease are its tendency to appear in explosive outbreaks and its predisposition to causing pandemics that may progressively affect many countries and spread into continents. Despite efforts to control cholera, the disease continues to occur as a major public health problem in many developing countries. Numerous studies over more than a century have made advances in the understanding of the disease and ways of treating patients, but the mechanism of emergence of new epidemic strains, and the ecosystem supporting regular epidemics, remain challenging to epidemiologists. In Nigeria, since the first appearance of epidemic cholera in 1972, intermittent outbreaks have been occurring. The later part of 2010 was marked with severe outbreak which started from the northern part of Nigeria, spreading to the other parts and involving approximately 3,000 cases and 781 deaths. Sporadic cases have also been reported. Although epidemiologic surveillance constitutes an important component of the public health response, publicly available surveillance data from Nigeria have been relatively limited to date. Based on existing relevant scientific literature on features of cholera, this paper presents a synopsis of cholera epidemiology emphasising the situation in Nigeria.

An assessment of the emergency response among health workers involved in the 2010 cholera outbreak in northern Nigeria.

BACKGROUND: 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. METHOD: This was a cross-sectional study with data collected through a self-administered questionnaire. Data entry and analysis were performed using Epi info software. RESULTS: 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. CONCLUSION: 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.

Predictors of surgical site infections of the abdomen in Lagos, Nigeria.

BACKGROUND: The issue of nosocomial infection constitute a significant burden on any health care facility particularly in resource constrained centers of many developing countries. OBJECTIVES: A prospective cross sectional study was designed to determine the baseline surgical site infection rate following abdominal surgeries, determine the influence of various factors on infection rates, evaluate the predictive value of the ASA, SENIC, NNIS indices on infection rates and identify the common aerobic and anaerobic organisms responsible for such infections. METHODS: One hundred and forty four consecutive patients who had abdominal surgeries were studied at the Lagos University, Teaching Hospital over a one year period. Demographic, clinical and other parameters were obtained with aid of a proforma. Those who developed surgical site infection had swabs taken for aerobic, anaerobic cultures and antimicrobial sensitivity. RESULTS: Wound infection rate was 17.4%. Surgeries involving the small bowels and the colon made up 75% of all infected cases. The predominant organisms isolated were Pseudomonas, enterobacter, proteus species Bacteroides was the most frequently isolated anaerobic organism. The predictive factors for infection were long surgeries, surgical procedures classified as contaminated or dirty, high ASA (American Society of Anaesthesilogist) scores, SENIC (Study of Efficacy of Nosocomial Infection Control), NNIS (National Nosocomial Infection Surveillance Index) scores. CONCLUSION: The predictive scores can be utilized to identify high risk surgeries and institute appropriate measures to reduce surgical site infections.

Molecular Characterization of the Circulating Strains of Vibrio cholerae during 2010 Cholera Outbreak in Nigeria.

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.