Molds are found both indoors and outdoors. Estimates of species of air borne molds range from tens of thousands to perhaps three hundred thousand. Molds grow best in warm, damp, and humid conditions, and spread and reproduce by spores [1,2]. Mold spores can survive harsh environmental conditions, such as dry conditions, that do not support normal mold growth. Some of the more common air molds include Cladosporium, Penicillium, Alternaria, and Aspergillus. Several studies have suggested a potential link of early mold exposure to development of asthma in some children, particularly among children who may be genetically susceptible to asthma development [1,2]. There is enhanced awareness of the importance of mold contamination in residential environments. Individual immune responses to these fungi may range from no symptoms to severe, depending on each person’s susceptibility to the allergen [3]. Several investigators have reported on the prevalence of outdoor and indoor air molds in different countries [4-7].

A wide variety of microorganisms including fungi are dispersed into the Caribbean region by the Saharan dust aerosols during the summer months. These microorganisms can cause diseases in plants and animals, and might possibly be responsible for an increase incidence of asthma and respiratory diseases in this region [8,9]. Information on the prevalence of air molds in the Caribbean region has been very much lacking. In a study from Cuba, the principal air-borne molds detected were Hormodendrum, Aspergillus, and yeasts, with many other genera being encountered occasionally. In another study in Cuba, Aspergillus, Cladopsorium and Penicillium spores were detected abundantly in different times of the day [10,11]. A Dominican study identified six genera of air born fungi including Aspergillus, Penicillium, Cladosporium, Fusarium, Curvularia, and Nigrospora [12].

The rationale for the present 2-part study was to propose a simple, cost effective and rapid model to monitor air borne molds around the world by first obtaining a mold count within the air of the smallest independent nation in the world and using Google maps to catalog the mold counts by location [13] and then further characterizing the air borne molds present in the island nation of St. Kitts along the same location. This 4 step model we hope will provide the know how to identify regions of high mold count, followed by characterization of the diversity of both the mold pathogenic and non-pathogenic molds distributed world-wide, Here we report the latter part and together the model could be adopted to cover the air over the landmass of the rest of the world. This information would be vital for ensuring the public health safety and food security.

The methodology to trap the molds is essentially the same as described earlier [13]. Duplicate Petri plates of Difco Sabaroud’s Dextrose agar (SDA (40 g/L dextrose, 10 g/L peptone, 20 g/L agar, pH 5. 6) were exposed for one hour at various pre-determined locations followed by a 48 hour incubation period at room temperature inside a bio-safety hood. Final mold count was obtained by repeating the entire process once again in duplicate with an exposure for a shorter periods than 1 hour for those that had a too many to count (TMTC) quantities of molds. The mold counts for those with shorter exposure were then multiplied by a factor equal to the fraction. If there was a 15 min exposure in the second round than the mold count was corrected for 1 hour by multiplying by a factor of 4. The average count/hour of exposure was obtained by averaging the mold count from the 2 separate exposures for the same location. Exposure locations included apartments and places of business because even these locations are susceptible to pathogenic fungal colonization. Places using electrical appliances to artificially modify the environment were included in the experiment as they have been shown, to potentially carry, the same risk for mold contamination [14]. Identification of the molds was attempted by a detailed study of colonial morphology and microscopic features as observed in lactophenol cotton blue mounts, and comparing the observed characteristics with descriptions given in standard books and manuals [15-17]. The distribution of molds identified is then using Google maps organized into pockets of air sampled providing a map of the location with the corresponding molds in the air of that location (Google map 1 and 2).

Twelve different locations on the island of St. Kitts were examined for fungi present in the air. More than 20 different species of fungi and yeasts were able to be identified. Cladosporium cladosporioides, Mucor sp and Aspergillus sp. were all found in 3 or more locations throughout the island. Other infrequently recovered molds included Curvularia, Alternaria, Fusarium solani, Metarrizum, Stachybortry, Trichosporon, Geotrichum, and Sporbolomyces. The brief detail of the isolations of molds from different locations are mentioned below

Mattingly heights-residential housing

A kitchen area in a house in Mattingly Heights was examined. This was one of the sites that showed mold overgrowth and the plates of SDA were re-exposed to air in this location for a shorter duration of 15 minutes and incubated until mold growth was manageable enough to isolate colonies. Based on microscopic analysis of fungal growth in Mattingly Heights, it was noted that predominant fungi prevalent in the air in the Camps Area were Mucor sp and Cladosporium cladosporioides (Figure 1).

Figure 1: Mattingly Heights.

Sea view gardens- neville’s restaurant

A restaurant by the main road in greater camps area called Neville’s was examined. This site also showed mold overgrowth and the plates of Sabouraud dextrose agar were re-exposed to air in this location, and incubated until appreciable mold growth occurred to recover cultures. Cladosporium cladosporioides was the predominant fungal agent in the air; a few colonies of Geotrichum candidum were also observed (Figure 2).

Figure 2: Neville’s Restaurant-Sea View Gardens.

Half moon bay- horizon’s villa

Residential housing area in the Half Moon Bay was examined. This site showed significant growth of Aspergillus fumigatus and Mucor sp, as evidenced by a large number of colonies of both species appearing on the plates (Figure 3).

Figure 3: Half Moon Bay-Horizons Villa.

Frigate bay

Ritual’s Coffee House, a restaurant and coffee house in Frigate Bay area was examined. This location showed growth of several colonies of fungi, mainly Cladosporium sp, Alternaria (A. alternata) and the yeast, and Trichosporon sp. (Figure 4).

Figure 4: Rituals Coffee House- Frigate Bay.

Ritual’s Sushi Restaurant in the Frigate Bay area was examined. Location showed multiple colonies of Cladosporium sp and Candida sp (Figure 5).

Figure 5: Rituals Sushi Restaurant- Frigate Bay.

Camps

A residential Housing in the Camps area was examined. Significant overgrowth was seen on test plates as well as master plate. Growth included several colonies of species of Aspergillus (mainly A.niger, A. fumigatus, and A. flavus). Mucor, Cladosporium sp, and Trichosporon sp. (Figure 6).

Figure 6: Camps Housing.

The lunch tent on the UMHS campus where most students eats meals while on campus was examined. Significant growth was seen and fungal species included Mucor sp, Aspergillus sp (Figure 7)

Figure 7: UMHS Lunch Tent-Camps.

UMHS campus

The Student Lounge on the on the East side of the Administration building was examined. Large colonies of growth were seen, including fungi and yeasts. The species predominant species was Aspergillus fumigatus, followed by Curvularia species. A few colonies of Bipolaris sp were also observed (Figure 8).

Figure 8: UMHS Student Lounge‐Camps.

The Best Buy Grocery Store located in Camps was examined. Large amount of mold growth was seen, including that of Rhodotorula sp. and Cladosporium sp. (Figure 9).

Figure 9: Best Buy.

The results are summarized in Table 1 and Table 2. In Table 1, all the molds are identified against locations around the Island. This gives a clear picture of which molds are found in several locations and Table 2 summarizes all the molds found within each location. It may be mentioned here that it was not possible to identify all the mold species year round to reflect seasonal differences and the identification of yeasts to specific level was not done due to lack of reagents and yeast identification kits. Therefore, while adopting this model for global surveillance in the future, it is advised to repeat mold counts
during all seasons experienced in the given geographical area.

Table 1: Mold II Sheet 1.

Table 2: Location of mold species.

The present investigation constitutes the first study of its kind dealing with the types of airborne molds in an island nation of St. Kiits. It is noteworthy that a variety of species were recovered in the agar plates exposed to air in different types of locations. The predominant fungi were Cladosporium (C. cladosporioides) and Aspergillus (mainly A. fumigatus, A. Niger and A. flavus). The presence of Aspergillus fumigatus in quantity in air has important health implications for humans and animals [18]. A. fumigatus is quite common in house dust, indoor and outdoor, in different types of soil, on decaying plant material, compost, and also on hay and crops. It is also an important etiological agent of systemic mycosis in domestic animals and in humans, especially the immunosuppressed and immunocompromised [19,20]. Aspergillus fumigatus, A. Niger and A. flavus have also been reported to cause allergies, asthma, and rhinitis in children and adults [20]. C. cladosporioides, a dematiaceous fungus is frequently encountered in indoor and outdoor environment occasionally linked to health problems [14]. Fusarium solani, a species infrequently recovered in this study is known to cause mycotic keratitis and skin infections in humans [20,21]. A. alternate, another dematiaceous mold occasionally encountered in this study has been recognized as risk factor for asthma [22]. Stachybotrys, occasionally encountered in our study is known to cause human disease through direct irritation, type 1, hypersensitivity or the production of toxins. A variety of respiratory, dermatological, eye and constitutional symptoms have been associated with heavy and prolonged exposure to S chartarum [23]. This novel detailed study outlining the 3-4 step design and methodology used can be adopted globally so that a Google map map of the mold count and the types of molds found can be generated with the ultimate goal or sharing tools to adopt for obtaining a world map. This information can be used to ensure public health by using appropriate masks and ensure food security by proper handling and preservation of food. Currently such a map exists for a few pathogenic molds like Histoplasma capsulatum present in the Ohio valley in USA, Coccoidiosis immitis present in the Southwest region of USA etc. The diversity of fungo that could directly or indirectly cause harm has not been sufficinetly studied in the past making this one of the early studies and attempts to obtain a handle at what else is in the air surroundin human inhabitants, plant and animal life. We envision that by expanding studies similar to ours where in the first step molds are captured in a culture plate and the molds then identified followed by relating the molds identified to the regions from an immediate vicinity and then expanding the geographical areas to ultimately cover the entire atmosphere of the whole world using our model of organizing the information gathered and emphasizing the unique molds that have been identified.

The authors gratefully acknowledge the Research Committee for evaluating the suitability of the project for medical students and the office of the Dean Camacho for assisting in allowing the use of the facilities for performing the experiments.