Risk factors for measles death: Kyegegwa District, western Uganda, February–September, 2015

Richardson Mafigiri, Fred Nsubuga, Alex Riolexus Ario

On 18 August 2015, Kyegegwa District reported eight deaths during a measles outbreak to the Uganda Ministry of Health (MoH). We investigated this death cluster to verify the cause, identify risk factors, and inform public health interventions. We defined a probable measles case as onset of fever and generalised rash in a Kyegegwa District resident from 1 February - 15 September 2015, plus ≥1 of the following: coryza, conjunctivitis, and cough. A confirmed measles case was a probable case with measles-specific IgM positivity. A measles death was a death of a probable or confirmed case-person. We conducted an active case-finding to identify measles patients who survived or died. In a case-control study, we compared risk factors between 16 measles patients who died (cases) and 48 who survived (controls), matched by age (±4 years) and village of residence. We identified 94 probable measles cases, 10 (11%) were confirmed by positive measles-specific IgM. Of the 64 probable measles patients aged <5 years, 16 died (case-fatality rate = 25%). In the case-control study, no history of vaccination against measles was found in 94% (15/16) among the case-persons (i.e., measles patients who died) and 54% (26/48) among the controls (i.e., measles patients who survived) (ORM-H = 12; 95% CI = 1.6-104), while 56% (9/16) of case-persons and 67% (17/48) of controls (ORM-H = 2.3; 95% CI =0.74-7.4) did not receive vitamin A supplementation during illness. 63% (10/16) among the case-persons and 6.3% (3/48) of the controls (ORM-H = 33; 95% CI = 6.8-159) were not treated for measles illness at a health facility (a proxy for more appropriate treatment), while 38% (6/16) of the case-persons and 25% (12/48) of the controls (ORM-H = 2.5; 95% CI = 0.67-9.1) were malnourished. Lack of vaccination and no treatment in a health facility increased the risk for measles deaths. The one-dose measles vaccination currently in the national vaccination schedule had a protective effect against measles death. We recommended enhancing measles vaccination and adherence to measles treatment guidelines.