Measles outbreak in Andalusia, Spain, January to August 2011

Area of Science:

• Epidemiology
• Virology
• Public Health

Background:

• Measles outbreaks pose a significant public health challenge, particularly in communities with lower vaccination rates.
• Understanding transmission dynamics and demographic impacts is crucial for effective control strategies.

Observation:

• A measles outbreak occurred in southern Spain starting in late 2010/early 2011, originating in a Roma community.
• The outbreak spread across Andalusia, affecting multiple towns and resulting in 1,759 confirmed or probable cases.
• Hospitalization was required for 19% of cases, with Measles virus genotype D4 identified in over half.

Findings:

• Clustered measles cases were significantly more prevalent in the 5-14 year-old age group (p<0.0001).
• Non-clustered cases were more common in individuals over 29 years old.
• Transmission patterns varied, with some areas experiencing widespread disease and others limited secondary cases.

Implications:

• The findings highlight the vulnerability of younger populations to clustered measles transmission.
• Targeted public health interventions and vaccination campaigns are essential for vulnerable communities.
• Genotype surveillance is important for tracking measles virus evolution and spread.