Background: Internal quality control is essential for preventing inaccuracy of disease causing microbial diagnostic, poor reagent quality and equipment dysfunction in a meningeal bacteria carriage study. This study aimed to assess the quality of meningococcal carriage study results obtained from Boussouma and Kaya health districts in the Center-North of Burkina Faso from 2016 to 2017.

Methodology: During the N. meningitidis carriage study, internal quality control was performed on culture media, field working conditions, reagents, laboratory equipment and antibiotics discs.

Result: During the carriage study, an evaluation of culture media was made. Thus, no defective or contaminated modified Thayer-Martin (TMM) were not recorded. On the other hand, we noted 86 defective fresh sheep blood agar (GSF) media and 201 other contaminated. Evaluation of sample collection conditions showed that the field ambient temperature was between + 22-+ 37°C. The duration of field sampling varied respectively from 77-173 minutes, 74-232 minutes, 74-195 minutes and 75-210 minutes at first, second, third and fourth campaign. The transport duration between sampling sites and the laboratory varied between 26-118 minutes, 21-187 minutes, 27-121 minutes and 25-137minutes at first, second, third and fourth campaigns. Thus, the delay of samples transmission from the first sample collection until all TMM media laboratory incubation varied respectively 145-264 minutes, 120-264 minutes, 126-288 minutes and 120-301 minutes at first, second, third and fourth campaign. TMM and GSF sterility control did not show any contamination. We did not observe any colony on TMM media with Proteus mirabilis (NC 04175) and Staphylococcus aureus (ATCC 25923) sowed for selectivity control. On the other hand, growth colonies were observed on TMM and GSF media with N. meningitidis A (ATCC 13077) and N. lactamica (ATCC 23970) reference strains. Reagents quality control showed that N. meningitidis A is Gamma-glutamyl-beta-naphthylamide (GGT) and oxidase positive and O-Nitrophenyl β-D-galactopyranoside (ONPG) negative. On the other hand, N. lactamica hydrolyzes ONPG, possesses cytochrome oxidase and is devoid of GGT. Incubator temperature varied between + 36.3- +36.7°C. Bacteria identification control showed good growth and suitable antisera agglutination with N. meningitidis A (ATCC 13077) reference strain. The strain storage temperature in the freezer ranged from -78--66°C. The refrigerator temperature used for reagents and media storage varied between + 2- +8°C. Finally, antibiotic discs tested gave good sensitivity with N. meningitidis A reference strain.

Conclusion: internal quality control system improved Neisseria meningitidis diagnosis in meningococcal A carriage study. It allowed assessing bacteriological diagnosis to obtain quality and reliable results in meningococcal A carriage study at CHR of Kaya laboratory in Burkina Faso from 2016 to 2017.

Quality control, Meningococcal A cariage, Burkina Faso