RESUMO
Meningococcal meningitis is a public health concern in Africa. Conjugated vaccine against serogroup A Neisseria meningitidis (MenAfriVac) was used in mass vaccination and was proved to have a good impact in the meningitis belt. There is a lack of information about the impact of this intervention in Cameroon after mass vaccination was undertaken. This study aimed at filling the gap in its unknown impact in Cameroon. A retrospective longitudinal study using biological monitoring data of case-by-case-based surveillance for meningitis was obtained from the National Reference Laboratories from 1 January 2009 to 20 September 2015. Immunization coverage data were obtained from Regional Public Health Delegations where immunizations took place. We compared the risks of vaccine serogroup occurrence before and after vaccinations and calculated the global impact using Halloran's formula. Annual cases of meningitis A decreased gradually from 92 in 2011 to 34 in 2012 and then to 1 case in 2013, and since 2014, no cases have been detected. The impact was estimated at 14.48% (p=0.41) in 2012 and then at 98.63% (p < 0.0001) after the end of vaccinations in 2013. This survey confirms the effectiveness of the MenAfriVac vaccine in Cameroon as expected by the WHO. The surveillance must be pursued and enhanced to monitor coming immunizations measures with multivalent conjugated vaccines for this changing threat.
RESUMO
BACKGROUND: The purpose of this study was to estimate the doses delivered to adult patients during chest examination for comparison with those elsewhere and to establish a local diagnostic reference level for the chest. The doses delivered in the standard X-ray examinations are not sufficiently optimized and controlled. The working protocols for the same exam given differ for similar morphotypes within the same hospital structure. MATERIALS AND METHODS: The entrance skin dose (mGy) of the chest was evaluated on 105 adult patients with a mass of 70 ± 10 kg in accordance with the 75th percentile of the irradiation parameters. The analysis and processing of the data was carried out by Excel 2010. The entrance skin dose of the chest obtained in mGy was 0.18 ± 0.21 for the PA incidence. CONCLUSION: The present study allowed us to observe large variations at the entrance skin doses of the chest. These variations have made it possible to understand that the entrance skin doses to the chest are optimized and do not exceed the proportions of those estimated by others and standards internationally. This aspect demonstrates that the diagnostic reference levels as enumerated are dependent on the doses delivered and include not only the notions of quality of the radiographic image and the quality assurance of the radiological equipments but also the level of the manipulators trained.
