INVESTIGATION OF MEASLES OUTBREAK IN YOKO HEALTH DISTRICT OF CAMEROON, FEBRUARY 2022: A CASE-CONTROL STUDY IN A PYGMY SETTLEMENT
In 2022, 30130 measles cases were reported with a fatality rate of 1.6% in Africa. In Cameroon the incidence of measles has doubled since 2021 with one-sixth of health districts reporting outbreaks in 2022. On February,
Centre Pasteur Cameroon, confirmed 22 cases in Yoko Heath District (YHD) in a Pygmy settlement. We aimed to describe the outbreak and implement control measures.
We conducted a 1:2 matched case-control study. Measles cases (MC) were patients with fever, generalized maculopapular rash and/or flu-like symptoms in YHD with epidemiological link to laboratory-confirmed cases from 23rd December 2021 to 4th March 2022. We used health facility registers to guide active case-finding in the community. Risk factors, socio-demographic and clinical data were collected using questionnaires. We assessed vaccination coverage among children <10 years and conducted an outbreak-response vaccination campaign. Odds ratios were used to determine significant associated factors.
We identified 83 MC with median age of 3 years [2 months - 40 years], female/male sex ratio of 1.13 and casefatality rate of 12%. The most affected age group were 1-5 year-old at 68,6% (57/83). Seventy-seven of the MC were identified in a Pygmy settlement. The predominant symptoms were fever, in 83/83(100%), rash in 79/83(95.2%) and cough in 66/83(79.5%) cases. Low education level of the family head (OR=6.3; 95%CI: 1.75-22.49), absence of measles vaccination (OR=4.79; 95%CI: 1.38-16.67) and malnutrition (OR=9.39; 95%CI: 1.88-46.92) were the main risk factors. Vaccination coverage for at least one dose was 71% (306/429 children). We vaccinated 4502 children against measles and caught up on the routine vaccination of children and pregnant women against other vaccine-preventable diseases.
Measles was linked with high mortality in the pygmy settlement. Absence of vaccination and malnutrition were the main risk factors. We recommend improving vaccination coverage and nutrition awareness in this vulnerable population.