I’ve been involved in project by the talented PhD student Sajidha Mohammed from the University of Calicut in India, who I informally co-supervise. Her project focusses on the negative role of insects found in houses in general, and mupli beetles in particular, on human health.

The first paper from her project has now been published in Oriental Insects. It analyses the occurrance of potential insects pests and self-reported illnesses from households in Malappuram in India. All the data was collected via extensive questionnaires. Overall, the study found a correlation between potential indoor environmental pollutants and the frequency of illnesses, although we did not find a direct correlation (only a weak insignificant trend) with the number of indoor insects reported. This might though be because occupants did not pay proper attention to insects or because other indoor biological pollutants (especially mould and mites) and outdoor pollutants (air pollution) may overshadow any effects. In any case more direct experimental data is needed to elucidate the relationship between the prevalence of indoor insects and human health.

Mohammad, S., Hesselberg, T. and Rafeeq, K.U.M.A. (2023). Occurrence of indoor insect pests and illnesses of inhabitants in Malappuram, Kerala, India. Oriental Insects. doi: 10.1080/00305316.2023.2217179

Abstract
Indoor insect pests have a direct and negative impact on human health by inflicting bites and stings, causing allergic reactions and transmitting diseases. Certain volatile and non-volatile organic compounds, secreted by indoor insect pests, are important components of indoor air quality. Volatile compounds have been associated with numerous health disorders. In this study, we used a questionnaire-based approach to quantify the insect populations from 403 indoor spaces along with the features of the indoor systems and the symptoms observed by the inhabitants. We recorded surrounding environmental variables, biological contaminants and possible reasons that the inhabitants thought were behind the increase in the number of certain pests. The indoor environment was the second most common reason attributed to the occurrence of indoor illness, likely due to the pandemic. We also found a significant relation between the indoor biological contaminants recorded and the increasing number of illnesses. Although insects were considered a nuisance in many households, they were not found to be directly related to higher numbers of ill inhabitants. Nonetheless, the increasing number of patients with allergies in the past few years and the increasing health issues reported from indoor spaces with higher pest populations indicates their potential impact.