Mosquito-borne Diseases, Fungal Spores, and Gastrointestinal Illnesses
o water samples matched Escherichia - Shi- gella gene sequences, while 86% of cisterns, 10% of coastal samples, and 3 out of the 3 (100%) runo samples matched Legionella spp. Enterococcus faecalis was present in 68% of cistern samples, 60% of coastal samples, and 2 out of the 3 (67%) runo samples. Hurricane Lane hit the city of Hilo, Hawaii, in August 2018, resulting in the wettest period on record in that region. A study that included the collection of coastal water samples after Hurricane Lane indicated the presence of a variety of Enterococcus spp . , many of which contained virulence genes as well as genes indicating resistances to antibiotics such as rifampin, nitrofurantoin, erythromycin, and tetracycline (Saingam et al., 2021). These Enterococcus spp . likely contaminated the waters from urban runo after the hurricane. In 2017, Hurricane Harvey decreased the salinity level of Galveston Bay (Yang et al., 2021). This incident in Texas is likely what allowed coliforms and pathogenic bacteria, as well as antibiotic-resistant genes, to prolif- erate 2 weeks after the hurricane. One study indicated that the fecal coliforms E. coli and Enterococcus spp. were detected in all samples collected from Galveston Bay . Salmonella spp. were detected in low levels in all water samples and at high levels in sediment, while Vibrio spp. were detected in water samples and sedi- ment. A similar study also found levels of E. coli elevated in bayou samples and an increased presence of antibiotic-resistant genes in these E. coli (Yu et al., 2018). As levels of bacteria change in response to environmental changes, it has been suggested that next-generation se- quencing could be used to assess water quality and identify which pathogens are present after hurricanes. Next-generation sequencing has already been used to show di erences in bac- terial constituents in flooded and non-flooded areas (Moghadam et al., 2022). In 2018, Hurricane Florence flooded areas of Eastern North Carolina that con- tain large numbers of poultry and swine farms (Niedermeyer et al., 2020). One study after Hurricane Florence focused on isolat- ing Campylobacter spp. but instead identi- fied Arcobacter butzleri in 73.5% of collected samples. A separate study involved collecting water from various natural sources around watersheds from 48 sites in Eastern North Carolina 1 week after Hurricane Florence and 1 month after landfall (Harris et al., 2021).
Methods involved aiming to quantify E. coli, Salmonella spp., Listeria spp., and Campylo- bacter spp. Results showed that E. coli was present in all samples with high levels of E. coli in channel and floodwater samples; the channel samples had the highest levels from the 1-month collection. Salmonella spp. were present in 6% of samples; nonpathogenic Listeria spp. were present in 18% of samples; and Listeria monocytogenes was present in one sample. No sample was found to be posi- tive for Campylobacter spp. A study that collected water samples in North Carolina after flooding from Hurri- cane Michael (October 2017) and Hurricane Florence (August 2018) indicated increased levels of Salmonella Typhimurium , Mycobac- terium spp., and Enterococcus spp . in nearly all samples collected from flooded locations (Usmani et al., 2023). Legionella spp., E. coli , and Pseudomonas spp. were increased in a few of the flood samples. The marked increase in Salmonella Typhimurium in agricultural locations was attributed to the flooding of swine farms. These studies collectively high- light the serious role that hurricanes play in increasing the number of pathogenic bacteria in wells and floodwater. Flesh-Eating Pathogens Increase After Hurricanes Recent news articles have indicated that deaths from the flesh-eating bacterium Vibrio vulnificus increased in Florida due to Hurri- cane Milton and Hurricane Helene in 2024 (Freeman, 2024). The total of 74 cases and 14 deaths in 2024 after the hurricanes exceeded the 46 cases and 11 deaths in Florida in 2023. This same trend also occurred in Florida after Hurricane Ian in 2022. There were 38 cases reported and 11 deaths associated with Vibrio spp . after Hurricane Ian (Sodders, 2023): 29 of these deaths were attributed to V. vulnificus , 3 to V. cholera, 2 to V. para- haemolyticus , 2 to V. fluvialis , and 2 to other Vibrio spp. One person was even coinfected with V. vulnificus and V. parahaemolyticus . Of the 38 cases, 79% of the cases were men and 80 years was the mean age of the individuals who were infected. It is vital that survivors of hurricanes—especially those with open wounds—heed warnings not to wade in open waters after a hurricane. Increases in Vibrio spp. infections after hurricanes are linked to climate change (Venkatesan, 2024).
Mosquito populations are a ected by the wind and rains of hurricanes. Hurricanes that occur before the peak of WNV transmission tend to have the greatest a ect on the number of WNV cases (Caillouët & Robertson, 2020). Evidence indicates that the number of cases of neuro- invasive disease from WNV is much greater when hurricanes occur early in the season. In addition to increasing mosquito viruses, wind and flooding from hurricanes can cause fungi to spread through air and water and can also increase the likelihood that fungi could be inhaled or injected directly into human tissue via trauma (Nnadi & Carter, 2021). Examples of fungal pathogens that can increase due to the occurrence of hurricanes are Candida auris, Cryptococcus gattii and C. deuterogattii . Like many infectious diseases, those infections due to Candida spp. and Cryptococcus spp. tend to be worse in indi- viduals with underlying comorbidities. Other fungi, which increase in warm and wet conditions resulting from tropical storms, a ect the yield of food crops. For example, Puccinia striiformis and Fusarium graminearum a ect wheat and other cereal crops at a greater rate after hurricanes, which indicates that global warming and climate change leads to decreased crop yield via fun- gal growth on crops. In addition to harming crops and spread- ing at an increased rate because of tropical storm conditions, fungal growth increases inside buildings after hurricanes. A study in San Juan, Puerto Rico, after Hurricane Maria in 2017 showed a change in the number of fungal spores (Vélez-Torres et al., 2022). The researchers examined 10 homes in non- flooded areas and 40 homes in flooded areas and collected indoor and outdoor samples 12 and 22 months after the hurricane. Par- ticipants self-reported whether their homes remained dry, were water damaged, or were flooded after the hurricane. Samples were collected, and the fungal colonies that grew on incubated Petri plates were counted. The researchers found that the number of colo- nies on the Petri plates was greater in flooded homes compared with non-flooded homes. The most abundant genera of fungi found in both indoor and outdoor samples in wet and dry homes after 12 months were Cladospo-
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July/August 2025 • Journal of Environmental Health
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