2011-07-02-世界卫生组织-Meningitis_Week_26,_27_June_-_3_July_2011_17页_507kb

Meningitis Weekly Bulletin Summary - Week 26, 2011

I. Epidemiological Situation of Week 26 (27 June - 3 July 2011)

• Data: Cases, deaths, case fatality rate (CFR), completeness, laboratory testing rates, and alert thresholds.
• Countries Reported (with Cases or Alerts): Benin (0,0), Burkina Faso (35,2 [CFR 5.7%]), Central Africa (7,2 [CFR 28.6%]), Ghana (15,2 [CFR 13.3%]), Mali (7,0 [CFR 0%]), Niger (6,1 [CFR 16.7%]), Nigeria (14,1 [CFR 7.1%]), DRC (212,26 [CFR 12.3%]), Chad (5,1 [CFR 20%]), Togo (3,0 [CFR 0%]).
• Highlights:
  • Ghana: Sissala-East district passed the alert threshold (AR 5.6 per 100,000) but reported low numbers (3 cases, 1 death).
  • Central Africa: 7 cases, 2 deaths in Bangui 1st Arrondissement await lab confirmation.
  • Meningitis Belt: Ongoing surveillance emphasized, even with zero cases. Lab confirmation of sporadic cases continued.
  • Summary: Week 26 marks the start of the inter-epidemic season. Total cases: 308, Deaths: 35 (CFR ~11.4%). Most districts were complete (>=86.7%) but Chad lagged at 86.7%.

II. Summary of the 2011 Epidemic Situation (Weeks 01-26)

• Key Points:
  • 2011 Cases & Deaths: ~19,940 cases, 1,772 deaths (CFR ~8.9%). Less severe than 2010 (~22,831 cases, ~2,415 deaths; CFR ~10.6%).
  • Vaccine Effect: Introduction of MenAfriVac (2010) reduced Neisseria meningitidis serogroup A (NmA) cases significantly. Zero NmA cases among vaccinated individuals.
  • Data Quality: Steady improvement in data completeness and timeliness for most countries.
  • Epidemic Foci: Cases primarily due to Streptococcus pneumoniae (Spn) and Neisseria meningitidis serogroup W135, mainly in southern Chad and northern Cameroon.

III. Pathogens Identified (by PCR, Latex, Culture - Week 26, 2011)

• PCR Testing: Burkina Faso led in PCR use.
• Prevalent Germs: S. pneumoniae (Spn) dominated, particularly in Burkina Faso. Neisseria meningitidis serogroup W135 was prominent in Niger. NmA cases were mostly from Chad and Cameroon.
• Lab Confirmation: Countries (especially Burkina Faso) made a strong effort in lab confirmation (~87% for suspected cases in Burkina Faso).

IV. Commentary

• Week 26 (beginning of inter-epidemic season) saw ongoing surveillance.
• Improved data submission noted.
• No worrying local epidemics reported for most high-risk areas, but standard lab confirmation awaited (Central Africa).
• Commentary focuses on the non-epidemic 2011 season compared to 2010, confirming reduced cases/impact post-vaccination.