Cyclone Idai as a Trigger for Pellagra Outbreak in Nhamatanda, Mozambique: A Case-Control Study

In mid-June 2019, 3 months after cyclone Idai landfall in Mozambique, health authorities of Nhamatanda district reported an outbreak of Pellagra. Applying a mixed-method protocol, we carried out an investigation to characterize cases of pellagra, identify the associated factors for the outbreak using a case-control study, and explore the perceived impact on food security (availability, access, and usage) before and after Idai. We collected data from 121 cases and 121 controls and conducted in-depth interviews with 69 heads of households. The cases were more likely to be female (P < 0.01) and less educated (P < 0.01) than controls. Insufficient consumption of chicken and peanut before cyclone Idai arrival were statistically associated with pellagra (P < 0.05). From interviewed households' heads, 51% were experiencing food shortages even before the cyclone hit. Cyclone Idai served as a trigger to reduce niacin consumption below the threshold that protected Nhamatanda population from pellagra and caused a X2,300 case (707.9/100,000 inhabitants) outbreak.

Automated summary

An outbreak of pellagra in Nhamatanda district, Mozambique, three months after cyclone Idai was found to be associated with factors such as being female, lower education level, and insufficient consumption of chicken and peanut before the cyclone hit. The cyclone exacerbated food shortages in households, leading to a significant increase in pellagra cases due to reduced niacin consumption.