Exotic Tourist Destinations and Transmission of Infections by Swimming Pools and Hot Springs-A Literature Review

Microbiological analysis, antimicrobial activity, heavy-metals content and physico-chemical properties of Fijian mud pool samples

The hot springs are home to a rich bacterial diversity which could be the source of enzymes, antibiotics and many other commercially important products. Most of the hot springs present in Fiji are unexplored and their analysis of microbial diversity could be of great interest in facilitating various industrial, agricultural and medicinal applications. This study is an attempt to evaluate the heavy metal concentration and to analyze the comprehensive bacterial diversity of two Fijian thermal mud pools, namely Sabeto and Tifajek. The two hot springs have a pH of 7.28 to 7.19 and a temperature of 32.2 to 38.8 °C, respectively. Mean metal concentrations of the studied mud samples ranged from 4.758 to 6.870 mg/kg and followed a decreasing sequence as Fe > Mn > Zn > Na > Ni > Cd > Ca > Cr > Cu. Levels of Fe, Na, Mn, Zn, Ni, Cd, Ca, Cr, Cu in the mud pool samples were within World Health Organisation (WHO) limits, while Cd was above regulatory limits. The heavy metals analysis results showed that both mud pools had high values for Cd, above the WHO limit of 3 mg/kg. In addition, 8 strains of actinomycetes were successfully identified for the first time in the Sabeto mud pool, where most of them showed antibacterial activity. The genetic identification of most isolates was determined in BLASTn analyses of their 16S rRNA sequences. Isolates were identified as that of Streptomyces, Nocardia and Rhodococcus genus. Further, AntiSMASH results of the closest relatives of cultured actinobacteria have shown to produce antibiotics, natural pesticides and other compounds of various usage. This study also found no fecal coliforms and supports existing knowledge and practice of using Fijian thermal mud pools for their therapeutic properties. Overall, the presented work indicated that the studied mud pools have therapeutic properties, harboring wealth of bacteria with antibiotic profiles and were risk free from health-related issues of heavy metals and disease-causing pathogens. It provides great insight into the studied mud pools which serves as a baseline from which further heavy metal monitoring or mitigation programs and microbial researches can be conducted.

High prevalence of vitamin D insufficiency among South Asian pregnant women: a systematic review and meta-analysis

Insufficiency of vitamin D, during pregnancy, is a common cause of various pregnancy-related complications. Despite such insufficiency being frequently reported among South Asian pregnant women, the absence of systematic review and meta-analysis renders the true extent of this problem being poorly characterised. In this systematic review, three main databases (PubMed, Scopus and Google Scholar) were searched for original studies. We included original studies published between 1January 2001 to 31 December 2019, conducted on pregnant women who lived in South Asian countries and reported the prevalence of vitamin D insufficiency among the study participants. Twenty studies with a total of 7804 participants from four South Asian countries finally met our selection criteria. Overall pooled prevalence of insufficiency was 65 % (95 % CI: 51 %, 78 %) with a significant heterogeneity (I² = 99·37 %; P = 0·00). The average level of vitamin D ranged from 9 ng/ml to 24·86 ng/ml with a weighted mean of 16·37 ng/ml (weighted standard deviation 7·13 ng/ml). The highest prevalence of insufficiency was found in Pakistan (76 %) followed by India (67 %), Bangladesh (64 %) and Nepal (14 %). Results obtained in this study suggest that vitamin D insufficiency is highly prevalent among South Asian pregnant women. Being the first systematic review in this region, findings from this study will help the future studies and strengthen the evidence for policymakers to develop effective mitigation strategies.

Prevalence of free-living amoebae in swimming pools and recreational waters, a systematic review and meta-analysis

Free-living amoebae (FLA) are cosmopolitan microorganisms known to be pathogenic to humans who often have a history of contact with contaminated water. Swimming pools and recreational waters are among the environments where the greatest human exposure to FLA occurs. This study aimed to determine the prevalence of FLA in swimming pools and recreational waters, through a systematic review and meta-analysis that included studies published between 1977 and 2022. A total of 106 studies were included and an overall prevalence of FLA in swimming pools and recreational waters of 44.34% (95% CI = 38.57–50.18) was found. Considering the studies published up to 2010 (1977–2010), between 2010 and 2015, and those published after 2010 (> 2010–2022), the prevalence was 53.09% (95% CI = 43.33–62.73) and 37.07% (95% CI = 28.87–45.66) and 45.40% (95% CI = 35.48–55.51), respectively. The highest prevalence was found in the American continent (63.99%), in Mexico (98.35%), and in indoor hot swimming pools (52.27%). The prevalence varied with the variation of FLA detection methods, morphology (57.21%), PCR (25.78%), and simultaneously morphology and PCR (43.16%). The global prevalence by genera was Vahlkampfia spp. (54.20%), Acanthamoeba spp. (33.47%), Naegleria spp. (30.95%), Hartmannella spp./Vermamoeba spp. (20.73%), Stenamoeba spp. (12.05%), and Vannella spp. (10.75%). There is considerable risk of FLA infection in swimming pools and recreational waters. Recreational water safety needs to be routinely monitored and, in case of risk, locations need to be identified with warning signs and users need to be educated. Swimming pools and artificial recreational water should be properly disinfected. Photolysis of NaOCl or NaCl in water by UV-C radiation is a promising alternative to disinfect swimming pools and artificial recreational waters.

Research on Schistosomiasis in the Era of the COVID-19 Pandemic: A Bibliometric Analysis

The objectives of this work are to check whether the COVID-19 pandemic affected the research on schistosomiasis, to provide an insight into the most productive countries and journals and the most cited publications, and to analyse any association between the total publications of countries and a set of socio-economic and demographic factors. Based on PRISMA methodology, we used the Scopus database to search for articles published between 1 January 2020 and 26 March 2022. VOSviewer was used to generate the co-authorship and the co-occurrence networks, and Spearman’s rank correlation was applied to study associations. A total of 1988 articles were included in the study. Although we found that the year-wise distribution of publications suggests no impact on schistosomiasis research, many resources have been devoted to research on COVID-19, and the Global Schistosomiasis Alliance revealed the main activities for eradication of schistosomiasis had been affected. The most productive country was the United States of America. The articles were mainly published in PLoS Neglected Tropical Diseases. The most prolific funding institution was the National Natural Science Foundation of China. The total publications per country were significantly correlated with population, GERD, and researchers per million inhabitants, but not with GDP per capita and MPM.

Risk Analysis of Otitis Externa (Swimmer’s Ear) in Children Pool Swimmers: A Case Study from Greece

Otitis is an ear inflammation characterized by an accumulation of polluted fluids in the ear, inflating the drum, causing ear pain, and draining the mucous membrane (pus) into the ear canal if the drum is perforated. Swimmer’s otitis, also known as acute external otitis, is a medical condition that frequently affects competitive swimmers. The risk factor analysis study was based on data obtained between May 2018 and May 2019 from four public swimming pools in Patras, Achaia. A checklist was created to evaluate the pools’ operational conditions, and it included information on the pools’ sanitation as well as swimming pool hygiene guidelines. In addition, a questionnaire was devised to collect data on pool swimmers’ use of the pools. Microbiological testing of the pool water was done ahead of time, and data on external otitis cases from hospitals was gathered. Based on this information, a risk factor analysis was conducted. Gender, weight, and age do not appear to have an impact on the number of otitis media cases that occur because of swimming in the pools. There is also no statistically significant link between episodes and the frequency of otitis events in locker rooms, restrooms, or swimming pools. The frequency with which swimmers utilize the pool, rather than the pool’s microbial burden, is the most significant determinant in otitis episodes. Furthermore, there is no statistically significant link between chlorine odor and otitis episodes. Additionally, several abnormalities in the ear or the child’s history do not appear to affect otitis episodes. More research is needed to determine whether infections are linked to microbial load or if other factors are responsible for the emergence of waterborne infections.

Comprehensive assessment of bacterial communities and their functional profiles in the Huang Gang Creek in the Tatun Volcano Group basin, Taiwan using 16S rRNA amplicon sequencing

The microbial characteristics of water bodies located in the outflow of hot springs may affect the water quality parameters of the associated river ecosystem. Using 16S rRNA amplicon sequencing, we investigated the bacterial diversity and functional profiles of the Huang Gang (HG) Creek, located in the trace metal-rich, acid-sulfate thermal springs zone of the Tatun Volcano Group (TVG). Biofilms and water samples were collected from the upstream, midstream, and geothermal valleys and downstream of the creek. The results showed that the biofilm and water samples had distinct bacterial diversity and abundance profiles. Acidophilic sulfur-oxidizing bacteria were found to be more abundant in water samples, whereas aquatic photosynthetic bacterial communities were dominant in biofilms. The water samples were contaminated with Legionella and Chlamydiae, which could contaminate the nearby river and cause clinical infections in humans. The upstream samples were highly unique and displayed higher diversity than the other sites. Moderate thermo-acidophiles were dominant in the upstream and midstream regions, whereas the geothermal valley and downstream samples were abundant in thermo-acidophiles. In addition, functional profiling revealed higher expression of sulfur, arsenic, and iron-related functions in water and lead-related functions in the biofilms of the creek. As described in previous studies, the hydrochemical properties of the HG Creek were influenced by the TVG hot springs. Our findings indicated that the hydrochemical properties of the HG Creek were highly correlated with the bacterial diversity and functional potential of running water as compared to biofilms.

High burden of hypovitaminosis D among the children and adolescents in South Asia: a systematic review and meta-analysis

Background

Vitamin D is vital for the growth and development of children. While deficiency and/or insufficiency of vitamin D among South Asian children are frequently reported in the literature, the lack of a meta-analysis has left its true extent poorly characterized. In this study, we aimed to conduct a systematic review and perform meta-analyses of the prevalence of hypovitaminosis D among the children of the South Asian countries.

Methods

Two major electronic search engines (PubMed and Scopus) and one database (Google scholar) were used; original studies, conducted among South Asian children and adolescents and published between 1 January 2001 and 31 December 2019. A random-effect meta-analysis was also performed to calculate the pooled prevalence of hypovitaminosis D followed by subgroup analyses for countries and age groups.

Results

After applying inclusion and exclusion criteria, a total of 41 studies with a total population size of 18,233 were finally selected. The overall prevalence of hypovitaminosis D was 61% [95% CI: 46% to 71%] with highly significant heterogeneity (I² = 99.72%; p < 0.0001). The average level of serum vitamin D ranged from 5 ng/mL to 34 ng/mL, with a weighted mean of 19.15 ng/mL (weighted standard deviation 11.59 ng/mL). Country-wise analysis showed that hypovitaminosis D in Afghanistan was the highest [96.2%; 95% CI: 91% to 99%], followed by Pakistan [94%; 95% CI: 90% to 96%], India [64%; 95% CI: 46% to 79%], Bangladesh [35.48%; 95% CI: 32% to 39%], Nepal [35%; 95% CI: 1% to 83%], and Sri Lanka [25%; 95% CI: 16% to 36%]. Age group analyses revealed that hypovitaminosis D was most prevalent among neonates [85%; 95% CI: 76% to 91%], followed by school-going children [57%; 95% CI: 33% to 80%], and preschool children [55%; 95% CI: 35% to 75%].

Conclusion

This study generates quantitative evidence and specific extent of hypovitaminosis D in the South Asian countries as a public health concern. Being the first systematic review for this region, results from this study will create awareness and will facilitate adopting mitigation strategies by the policymakers and the governments to address this problem.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41043-022-00287-w.

A case of a renal abscess caused by Salmonella bareilly in a previously healthy boy

Background

Renal abscesses are relatively uncommon in children, and usually due to Gram-negative rods or Staphylococcus aureus, whereas abscesses caused by Salmonella are very rare.

Case presentation

We present the case of a previously healthy 10-year-old boy who had a renal abscess due to Salmonella bareilly. He responded well to treatment with antibiotics, and computed tomography (CT)-guided drainage of the abscess. His blood, urine and abscess aspirate cultures were sterile, but a broad-range 16S rDNA polymerase chain reaction (PCR) assay of the aspirate followed by analysis of four Salmonella genes (fliC, fliD, sopE2, and spaO) identified S. bareilly as the causative agent.

Conclusion

To the best of our knowledge, this is the first report of renal abscess caused by S. bareilly.

Microbial pollution in inland recreational freshwaters of Quetta, Pakistan: an initial report

Parasitic contamination of surface waters, especially recreational waters, is a serious problem for under-developed nations like Pakistan, where numerous outbreaks of parasitic diseases are reported each year. In the current study, parasitic presence in two surface waters (Hanna Lake and Wali-Tangi Dam) of Quetta was monitored quarterly for 1 year. The methodology involved the pre-concentration of the water samples and the subsequent preparation for the microscopic search of parasites. Physico-chemical and bacteriological variables were also studied. Wet staining, modified Trichrome staining, and modified acid-fast staining methods were used to identify various parasitic forms (cysts, oocysts, eggs, trophozoites). Collectively 11 parasitic elements (10 in Lake and 8 in Dam) belonging to 10 species were recorded, many of which are potential human pathogens. The species identified include Trichomonas sp., Isospora sp., Balantidium coli, Cryptosporidium sp., Entamoeba spp., amoebas, Microsporidium sp., Endolimax nana, Ascaris lumbricoides, and Giardia spp. Parasitic contamination remained persistent in both locations throughout the year independent of physico-chemical parameters (temperature, EC, pH, turbidity, and DO) and bacterial concentration of water. Reliance on bacterial presence for monitoring of recreational waters can be a risk for tourists. Entamoeba spp. and A. lumbricoides may be used for surface water monitoring in these waters.

Fungal contamination of indoor public swimming pools and their dominant physical and chemical properties

Introduction

Considering the existence of both parasitic and fungal pathogens in the indoor public swimming pools and non-utilization of suitable filtration and disinfection systems in these places, this research aimed to determine the relationship between the indoor public swimming pools and possible pollution with parasitic and fungal agents, as well as physical and chemical characteristics of these pools and compare the results with national standards.

Methods

In this study, 11 active indoor swimming pools of Zahedan city were sampled, using plastic pump techniques, from the middle of winter to the late summer season. A total of 88 water samples (eight water samples from each pool) were examined to determine the residual chlorine, contamination with parasitic and fungal agents, using culture media and slide culture techniques. Results were analyzed with SPSS software (V16) and, Microsoft Excel (V2010).

Results

The findings revealed fungal contamination with Cladosporium, Penicillium, Aspergillus flavus and Aspergillus fumigatus, etc. and the physicochemical factors comply with the minimum standards, which indicates the need for continuous monitoring and control of water filtration and disinfection of water in the pools.

Conclusion

The results show reasonable derangement of physicochemical and microbial factors of the evaluated pools. Efforts shall be made by the concerned authorities to provide health education to users, quality water at the pools and to maintain the safety and quality of the water through proper and adequate chlorination.

High prevalence of vitamin D deficiency among the South Asian adults: a systematic review and meta-analysis

Background

Vitamin-D deficiency is linked to a wide range of chronic and infectious diseases. Body of literature suggested that the prevalence of this deficiency can have geographical variation. Although vitamin D deficiency is frequently reported in the South Asian population, the scarcity of systematic reviews and meta-analysis means the true extent of the disease and the underlying factors causing it are poorly characterized.

Methods

A systematic search was performed using two databases (PubMed and Scopus) and one search engine (Google Scholar) for original studies on the South Asian population (published from January 1, 2001, to December 31, 2019). Following the search, a random effect meta-analysis was performed to calculate population-level weighted average, the pooled prevalence of deficiency, and heterogeneity of vitamin D among different countries and genders; in addition to South Asia as a whole.

Results

Our study, based on our selection criteria was narrowed down to a total of 44,717 participants; which spanned over 65 studies from five South Asian countries. Overall, the pooled prevalence of deficiency was 68% [95% CI: 64 to 72%] with significant heterogeneity (I² = 98%; p = 0.00). The average level of vitamin D ranged from 4.7 to 32 ng/mL, with a weighted mean of 19.15 ng/mL (weighted standard deviation 11.59 ng/mL). The highest prevalence of vitamin D deficiency was found in Pakistan (73%;95% CI: 63 to 83%) followed by Bangladesh (67%; 95% CI: 50 to 83%), India (67%; 95% CI: 61 to 73%), Nepal (57%; 95% CI: 53 to 60%) and Sri Lanka (48%; 95% CI: 41 to 55%), respectively. This finding indicated a high degree of heterogeneity among the population. (I² = 98.76%), Furthermore, a gender-wise analysis suggested that in South Asia, the prevalence of vitamin D deficiency was higher in females than males.

Conclusion

Our findings reveal highly prevalent and variable vitamin D deficiency among the adults of different South Asian countries. Findings from this review would be helpful to generate hypotheses and explore the factors affecting the inter-country variability, alongside strengthening evidence for governments to prioritize mitigation strategies in this region.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11888-1.

Assessment and valuation of health impacts of fine particulate matter during COVID-19 lockdown: a comprehensive study of tropical and sub tropical countries

A novel coronavirus disease (COVID-19) continues to challenge the whole world. The disease has claimed many fatalities as it has transcended from one country to another since it was first discovered in China in late 2019. To prevent further morbidity and mortality associated with COVID-19, most of the countries initiated a countrywide lockdown. While physical distancing and lockdowns helped in curbing the spread of this novel coronavirus, it led to massive economic losses for the nations. Positive impacts have been observed due to lockdown in terms of improved air quality of the nations. In the current research, ten tropical and subtropical countries have been analysed from multiple angles, including air pollution, assessment and valuation of health impacts and economic loss of countries during COVID-19 lockdown. Countries include Brazil, India, Iran, Kenya, Malaysia, Mexico, Pakistan, Peru, Sri Lanka, and Thailand. Validated Simplified Aerosol Retrieval Algorithm (SARA) binning model is used on data collated from moderate resolution imaging spectroradiometer (MODIS) for particulate matters with a diameter of less than 2.5 μm (PM2.5) for all the countries for the month of January to May 2019 and 2020. The concentration results of PM2.5 show that air pollution has drastically reduced in 2020 post lockdown for all countries. The highest average concentration obtained by converting aerosol optical depth (AOD) for 2020 is observed for Thailand as 121.9 μg/m3 and the lowest for Mexico as 36.27 μg/m3. As air pollution is found to decrease in the April and May months of 2020 for nearly all countries, they are compared with respective previous year values for the same duration to calculate the reduced health burden due to lockdown. The present study estimates that cumulative about 100.9 Billion US$ are saved due to reduced air pollution externalities, which are about 25% of the cumulative economic loss of 435.9 Billion US$.

Death From Primary Amebic Meningoencephalitis After Recreational Water Exposure During Recent Travel to India-Santa Clara County, California, 2020

Background

In February 2020, a man returned to the United States after an 11-day trip to India and died of primary amebic meningoencephalitis (PAM), caused by nasal exposure to the free-living ameba Naegleria fowleri found in warm water. We identified potential exposures, confirmed etiology, and described the molecular epidemiology of the infection.

Methods

We reviewed medical records to describe his clinical course and interviewed his family to determine water exposures. Genotyping was performed on the N. fowleri strain and compared with North American strains through repetitive nonpolymorphic nuclear loci analysis to identify differences. We reviewed N. fowleri strains in the National Center for Biotechnology Information database (GenBank) to determine genotypes present in India.

Results

The patient became acutely encephalopathic 3 days after returning; the only known nasal water exposure was at an indoor swimming pool in India 5 days earlier. Cerebrospinal fluid (CSF) testing demonstrated neutrophil-predominant pleocytosis and low glucose, but negative gram stain and culture. CSF microscopy revealed trophozoites; N. fowleri was detected by real-time polymerase chain reaction. Classical genotyping confirmed genotype I, common in the United States and among Indian strains in GenBank. The North American N. fowleri strains and the patient's strain varied at 5 nonpolymorphic loci.

Conclusions

A man died from PAM after likely exposure at a vacation rental pool in India. We recommend including PAM in the differential diagnosis when CSF studies suggest bacterial meningitis but gram stain is negative. Genotyping can advance our understanding of N. fowleri molecular epidemiology and support future investigations.

Diversity and composition of the North Sikkim hot spring mycobiome using a culture-independent method

Fungi are considered to be the most resilient and economically important microbial community that can easily survive and optimally grow under a wide range of growth conditions. Thermophilic fungi from the geothermal sources have been less pondered upon and lie unexplored. Here, a microbiome approach was conducted to understand the concealed world of the environmental mycobiota from the two hot springs of North Sikkim district located in North-east India. The solfataric muds from the hot springs were analyzed. In both the samples, on the basis of genus level classification, genus Fusarium had the highest abundance followed by Colletotrichum, Pochonia, Pyricularia, Neurospora, etc. Analyzing the predicted genes, the functional proteins of New Yume Samdung mycobiome were found to be dominated by the genera Fusarium (22%), Trichoderma (12%), and Aspergillus (11%), whereas in the case of Old Yume Samdung, it was dominated by the genera Aspergillus (11%), Saccharomyces (6%), and Fusarium (5%). Interestingly, in the studied mycobiome, environmental yeasts were also detected. From the functional metagenomics, sulfate adenylatetransferase (SAT) proteins for sulfur assimilation were found in some of the fungal reads. Toxin protein reads such as AM-toxin biosynthesis proteins, AF-toxin biosynthesis proteins, Gliotoxin biosynthesis proteins, and aflatoxin biosynthesis proteins were detected in the mycobiomes.

Evaluation of the occurrence of pathogenic free-living amoeba and bacteria in 20 public indoor swimming pool facilities

Recently, indoor swimming pool activities have increased to promote health-enhancing physical activities, which require establishing suitable protocols for disinfection and water quality control. Normally, the assessment of the microbial quality of the water in the pools only considers the presence of different bacteria. However, other less frequent but more resistant pathogens, such as free-living amoebas (FLA), are not contemplated in both existing recommendation and research activities. FLA represent a relevant human health risk, not only due to their pathogenicity but also due to the ability to act as vehicles of other pathogens, such as bacteria. Therefore, this work aimed to study the physicochemical characteristics and the occurrence of potentially pathogenic FLA and bacteria in water samples from 20 public indoor swimming facilities in Northern Portugal. Our results showed that some swimming pools presented levels of pH, free chlorine, and conductivity out of the recommended limits. Pathogenic FLA species were detected in two of the facilities under study, where we also report the presence of both, FLA and pathogenic bacteria. Our findings evidence the need to assess the occurrence of FLA and their existence in the same environmental niche as pathogenic bacteria in swimming pool facilities worldwide and to establish recommendations to safeguard the health of the users.

The microbiota as a candidate biomarker for SPA pools and SPA thermal spring stability after seismic events

Worldwide, the location of thermal springs overlaps seismic areas, and the higher occurrence of earthquakes may impact on water stability and safety. The hydrogeological perturbations pose environmental and public health risks that can be monitored by well-established chemical, physical and biological parameters. Specific health concerns involve the exposure of the population to the medical or wellness uses of SPA thermal waters, e.g. in respiratory or hydropinic treatments as well as during rehabilitative or recreational activities in pools. Since SPA waters are characterized by their own microbiota, we analysed by 16S amplicon sequencing the dynamics of water microbial communities after the August 2017 Ischia island earthquake. For the first time, we report the impact of a seismic event on a thermal spring water, whose microbiota was deeply characterized before and immediately after the natural disaster. The biodiversity stability of the water underwent a dramatic disturbance following the earthquake, as summarized by a Shannon index moving from 1.300 during May 2016-July 2017, up to 1.600 during the first 20-70 h after the event and slightly slowing down to 1.500 after 30 days and to 1.400 after 6 months. Microbiota analysis showed a sudden reduction of the relative abundance of autochthone thermophilic species within the first 20 h and a parallel increase of other thermophilic species as well as of ectopic bacteria from soil, sediments, sea, freshwater and wastewaters. Cultivable mesophilic bacteria were observed only in the first 20 h sample (7 × 10³/L), even if the presence of faecal contamination traces was detected by Real Time PCR also up to 70 h after the disaster. OTUs analysis of putative metabolic functions showed several changes between pre and post event, such as in the distribution of Sulphur metabolizing and Carbon fixation species. The restoration of the original pattern followed a slow trend, requiring over six months. The observed results confirm the impact of the earthquake on the microbiota structure of the underground thermal spring water, suggesting further perspectives for monitoring water stability and safety issues by a metagenomic approach.

Untouchability of natural spa waters: Perspectives for treatments within a personalized water safety plan

Natural SPA waters and their environments were known since ancient times and used for health or recreational purposes in different societies, worldwide. The composition and uses of these spring waters may not allow standard disinfection in pools, representing a challenge for hygiene management. Several safety and quality procedures were proposed, but a systematic approach is still needed. Here, we focus on alternative strategies to provide hints for developing a sustainable Water Safety Plan, based on intrinsic water properties and photocatalytic materials. The antimicrobial activity of four different SPA waters with high mineral content and one drinkable spring water with a low mineral content, was assessed and then tested for the additional bactericidal activity of Titanium Dioxide (TiO₂) nanomaterials and/or light exposure at different wavelengths (200-635 nm). A native antibacterial activity was observed in all high mineral content waters, with a CFU reduction of 75-80%. The bactericidal action of TiO₂ showed an additional incremental effect, with a reduction of over 99% within 2-5 h. Interestingly, the antibacterial photocatalytic effect was detected also in the visible light range, with a possible pick around 450-455 nm, blue-light. Based on observed results, we propose a model for developing a water safety plan, considering water properties and bather exposure. This candidate approach is personalized on water composition and pool use, trying to avoid chemical disinfectants. Photocatalytic nanotechnologies represent one of the promising alternative treatments and can provide novel perspectives for a sustainable managing of natural SPA water hygiene.