Influence of ventilation use and occupant behaviour on surface microorganisms in contemporary social housing

Abstract

In the context of increasingly airtight homes, there is currently little known about the type and diversity of microorganisms in the home, or factors that could affect their abundance, diversity and nature. In this study, we examined the type and prevalence of cultivable microorganisms at eight different sites in 100 homes of older adults located in Glasgow, Scotland. The microbiological sampling was undertaken alongside a household survey that collated information on household demographics, occupant behaviour, building characteristics, antibiotic use and general health information. Each of the sampled sites revealed its own distinct microbiological character, in both species and number of cultivable microbes. While some potential human pathogens were identified, none were found to be multidrug resistant. We examined whether the variability in bacterial communities could be attributed to differences in building characteristics, occupant behaviour or household factors. Sampled sites furnished specific microbiological characteristics which reflected room function and touch frequency. We found that homes that reported opening windows more often were strongly associated with lower numbers of Gram-negative organisms at indoor sites (p < 0.0001). This work offers one of the first detailed analysis of cultivable microbes in homes of older adults and their relationship with building and occupancy related factors, in a UK context.

Figure 1

Mean and standard deviation of microorganisms across the eight sample locations over all homes.

Figure 2

Mean difference plots representing Tukey HSD post-hoc comparisons between sites. Comparisons that do not pass through 0 are significantly different.

Figure 3

Microbial diversity % score plotted against log₁₀ ACC on nutrient agar including a 95% confidence interval.

Figure 4

(a) Presence of Gram-negatives and (b) Fungi vs percentage of window opening day and night combined.

Figure 5

Boxplots of (a) microbial diversity and (b) log₁₀ ACC on nutrient agar in relationship to: “Have you taken antibiotics recently?”.

Figure 6

Plot of disinfectant diversity score against log10 ACC including a 95% confidence interval.

Figure 7

Study dwelling locations (created using Google My Maps: Mapdata©2020).

Figure 8

Double-sided dipslide: example from bathroom door handle.