Underdetection of COVID-19 cases in France in the exit phase following lockdown

A novel testing policy was implemented in May in France to systematically screen potential COVID-19 infections and suppress local outbreaks while lifting lockdown restrictions. 20,736 virologically-confirmed cases were reported in mainland France from May 13, 2020 (week 20, end of lockdown) to June 28 (week 26). Accounting for missing data and the delay from symptom onset to confirmation test, this corresponds to 7,258 [95% CI 7,160-7,336] cases with symptom onset during this period, a likely underestimation of the real number. Using age-stratified transmission models parameterized to behavioral data and calibrated to regional hospital admissions, we estimated that 69,115 [58,072-77,449] COVID-19 symptomatic cases occurred, suggesting that 9 out of 10 cases with symptoms were not ascertained. Median detection rate increased from 7% [6-9]% to 31% [28-35]% over time, with regional estimates varying from 11% (Grand Est) to 78% (Normandy) by the end of June. Healthcare-seeking behavior in COVID-19 suspect cases remained low (31%) throughout the period. Model projections for the incidence of symptomatic cases (4.5 [3.9-5.0] per 100,000) were compatible with estimates integrating participatory and virological surveillance data, assuming all suspect cases consulted. Encouraging healthcare-seeking behavior and awareness in suspect cases is critical to improve detection. Substantially more aggressive and efficient testing with easier access is required to act as a pandemic-fighting tool. These elements should be considered in light of the currently observed resurgence of cases in France and other European countries.

Emergence of Neisseria meningitidis W135 in Cote d'Ivoire: laboratory based-surveillance / 한국역학회지

OBJECTIVES: To describe the emergence of Neisseria meningitidis (Nm) W135 in Côte d'Ivoire and its characteristics compared to NmA. METHODS: Data on Nm samples isolated at the National Reference Center for meningitis in Côte d'Ivoire between 2007 and 2012 were analyzed. Socio-demographic data and biological information on the samples were extracted from the database. Categorical variables, such as sex and the serotype of the bacteria, were compared using the Fisher exact test, while the distribution of continuous variables, such as age, was compared using the Wilcoxon test. RESULTS: Among the 175 Nm samples, 57 were NmA, 4 were NmB, 13 were NmC, and 99 were NmW135. The geographical distribution of NmA and NmW135 did not show a significant difference according to age or sex. NmW135 was more common than NmA in the northern health districts of Cote d'Ivoire (85.9 vs. 45.5%; p < 0.001). No sample of NmA has been isolated since 2009, while 95% of the type W135 samples were isolated between 2010 and 2012. CONCLUSION: This study highlighted the emergence of NmW135 in Côte d'Ivoire, as well as the simultaneous disappearance of NmA. It is important to improve laboratory-based surveillance of meningitis to assess trends in the circulation of bacteria and to detect the emergence of new serogroups earlier.

Emergence of Neisseria meningitidis W135 in Cote d'Ivoire: laboratory based-surveillance / 한국역학회지

OBJECTIVES: To describe the emergence of Neisseria meningitidis (Nm) W135 in Côte d'Ivoire and its characteristics compared to NmA.METHODS: Data on Nm samples isolated at the National Reference Center for meningitis in Côte d'Ivoire between 2007 and 2012 were analyzed. Socio-demographic data and biological information on the samples were extracted from the database. Categorical variables, such as sex and the serotype of the bacteria, were compared using the Fisher exact test, while the distribution of continuous variables, such as age, was compared using the Wilcoxon test.RESULTS: Among the 175 Nm samples, 57 were NmA, 4 were NmB, 13 were NmC, and 99 were NmW135. The geographical distribution of NmA and NmW135 did not show a significant difference according to age or sex. NmW135 was more common than NmA in the northern health districts of Cote d'Ivoire (85.9 vs. 45.5%; p < 0.001). No sample of NmA has been isolated since 2009, while 95% of the type W135 samples were isolated between 2010 and 2012.CONCLUSION: This study highlighted the emergence of NmW135 in Côte d'Ivoire, as well as the simultaneous disappearance of NmA. It is important to improve laboratory-based surveillance of meningitis to assess trends in the circulation of bacteria and to detect the emergence of new serogroups earlier.

Emergence of Neisseria meningitidis W135 in Cote d'Ivoire: laboratory based-surveillance / 한국역학회지

OBJECTIVES@#To describe the emergence of Neisseria meningitidis (Nm) W135 in Côte d'Ivoire and its characteristics compared to NmA.@*METHODS@#Data on Nm samples isolated at the National Reference Center for meningitis in Côte d'Ivoire between 2007 and 2012 were analyzed. Socio-demographic data and biological information on the samples were extracted from the database. Categorical variables, such as sex and the serotype of the bacteria, were compared using the Fisher exact test, while the distribution of continuous variables, such as age, was compared using the Wilcoxon test.@*RESULTS@#Among the 175 Nm samples, 57 were NmA, 4 were NmB, 13 were NmC, and 99 were NmW135. The geographical distribution of NmA and NmW135 did not show a significant difference according to age or sex. NmW135 was more common than NmA in the northern health districts of Cote d'Ivoire (85.9 vs. 45.5%; p < 0.001). No sample of NmA has been isolated since 2009, while 95% of the type W135 samples were isolated between 2010 and 2012.@*CONCLUSION@#This study highlighted the emergence of NmW135 in Côte d'Ivoire, as well as the simultaneous disappearance of NmA. It is important to improve laboratory-based surveillance of meningitis to assess trends in the circulation of bacteria and to detect the emergence of new serogroups earlier.