Diet-Related Risk Factors for Leprosy: A Case-Control Study

Background: Food shortage was associated with leprosy in two recent studies investigating the relation between socioeconomic factors and leprosy. Inadequate intake of nutrients due to food shortage may affect the immune system and influence the progression of infection to clinical leprosy. We aimed to identify possible differences in dietary intake between recently diagnosed leprosy patients and control subjects. Methods: In a leprosy endemic area of Bangladesh, newly diagnosed leprosy patients and control subjects were interviewed about their socioeconomic situation, health and diet. Dietary intakes were recorded with a 24-hour recall, from which a Dietary Diversity Score (DDS) was calculated. Body Mass Index (BMI) was calculated and Household Food Insecurity Access Scale (HFIAS) was filled out for every participant. Using logistic regression, a univariate, block wise multivariate, and an integrated analysis were carried out. Results: 52 leprosy cases and 100 control subjects were included. Food shortage was more common, dietary diversity was lower and household food insecurity was higher in the patient group. Patients consumed significantly less items from the DDS food groups ‘Meat and fish’ and ‘Other fruits and vegetables.’ Lower food expenditure per capita, lower BMI, lower DDS and absence of household food stocks are the main factors associated with an increased risk of having leprosy. Conclusion: Low income families have only little money to spend on food and consequently have a low intake of highly nutritious non-rice foods such as meat, fish, milk, eggs, fruits and vegetables. Development of clinical leprosy could be explained by deficiencies of the nutrients that these foods normally provide. Author Summary: Even though leprosy is one of the oldest diseases known to mankind, there is still a lot unknown about its transmission and why some people develop the disease and others do not. Leprosy is often seen as a disease of the poor, but which aspects of poverty are associated with leprosy are still under study. Recently though, food shortage has been identified as a risk factor for leprosy in two socioeconomic studies. In our study, lead in a poor area of Bangladesh, we further investigated this link by interviewing recently diagnosed leprosy patients during a food shortage period. We found that compared to a control population, leprosy patients have less money to spend on food, have less household food stocks and have a less diverse diet. The patient group had a lower consumption of highly nutritious foods such as meat, fish, eggs, milk, fruits and vegetables. An inadequate diet for a longer period of time leads to nutrient deficiencies. The body’s immune system, however, needs proteins, vitamins and minerals to effectively fight off infections. We conclude that people who are living in poverty and who are not able to get an adequate, diverse diet have a higher chance of developing leprosy.