• The increasing dryness of soils in March may be compounded by short term drought in a number of locations across the region. The associated increase in dust, as well as, potential soot and smoke from wildfires may contribute to higher concentrations of airborne particulate matter. This could result in an increase in acute respiratory illnesses. The level of concern is expected to decrease by the month of May.
• There may be an increase in symptoms in persons with chronic respiratory conditions such as asthma, and in persons prone to allergic rhinitis due to more frequent episodes of Saharan dust incursions into the Caribbean, as well as due to local dust being suspended in the air when the ground surface is dry.
• This may be offset by a decrease in allergic reactions due to the dryness, resulting in reduction in fungal spores from mould at least until the end of March. By contrast, increasing humidity across the region from April onwards could cause dampness in some poorly ventilated residences and offices resulting in the growth of mould. In the Caribbean islands, increased allergens in the atmosphere may occur from plant materials (e.g. pollen) driven by increased wind speeds. These factors may also trigger more frequent occurrence of upper respiratory tract symptoms.
• Where episodes of flooding may occur, there is an increased risk of ear, nose, and throat infections from contaminated water across the region, particularly in April and May.

• Ongoing dryness and drought conditions may increase concentrations of water pollutants. Additionally, a drop in water pressure in the pipes of water supply systems may result in cross contamination and reduced access to water. Alternative use of unsafe sources of water, in turn may potentially contribute to higher incidences of gastrointestinal illness.
• Cases of gastroenteritis may increase in frequency across the region from April due to contamination of food and water supplies, and contact with flood waters.

• Higher temperatures and the occurrence of heat waves begin in April across the region, with the likely exception of the Guianas. This can increase the risk of morbidity from heat-related health effects, resulting in a possible increase in hospitalisations and emergency room visits. Such effects include apathy, general weakness, dizziness, fainting, exhaustion (heat strain) and, in extreme cases, lead to kidney failure. These effects may be exacerbated in persons with chronic illness, persons taking some medications, children, pregnant women, the elderly, outdoor workers and people in situations of excessive exposure to outdoor hot conditions. For information on heat and health see: https://www.who.int/health-topics/heatwaves#tab=tab_1 and https://ghhin.org/
• During this period, excessive exposure due to dangerous UV radiation can cause skin damage in persons who spend extended periods outdoors, especially on sunny days, if unprotected (for more information, see: https://www.epa.gov/sunsafety/uv-index-scale-0). For simple action steps on sun protection, see: https://www.who.int/news-room/questions-and-answers/item/radiation-the-ultraviolet-(uv)-index
• There is the increasing possibility of skin infections due to contact with contaminated stagnant and/or floodwaters in the region from April onwards.

• Increased rainfall and the more frequent occurrence of stagnant water from flooding from April onwards may create more breeding sites for the Aedes aegypti and Aedes albopictus mosquitoes which are the vectors of diseases such as Dengue, Chikungunya, Zika and Yellow Fever. These diseases remain a perennial concern for Caribbean territories.
• With increasing dryness and recurrent dry spells across the region in March, and, in some locations, going into April, there may be increased use of containers for water storage. This may be further exacerbated in Cuba, French Guiana, southern Puerto Rico, and other areas where drought is evolving.
• At the household level, careful attention should be given to the management of water storage containers. This includes mosquito proofing water tanks, barrels, drums and buckets.
• The focus should be on public education and awareness on source reduction and personal protection. If fogging operations are considered by a country’s Ministry of Health, advice should be sought from the local meteorological services on temperature, wind speed, humidity, etc.
• Access useful materials on mosquito control measures here: (https://www.paho.org/en/campaigns/caribbean-mosquito-awareness-week-2020); Join the fight against mosquito borne disease in the Caribbean: https://carpha.org/What-We-Do/Public-Health/Dengue and http://missionmosquito.carpha.org/
• Additionally, countries in in the Guianas may experience increasing malaria transmission corresponding with the periods of increased rainfall. Use of insecticide treated mosquito nets is strongly recommended to limit human-vector contact while sleeping.
• Flooding may increase the risk of Leptospirosis due to displacement of rodent vectors from their usual habitats into houses, increasing the risk of contamination of slow moving or stagnant waters, household surfaces and food-stores with rodent urine.

• Severe weather systems, which can come with a range of hazards, including high winds, landslides, flash floods, among others, may possibly affect Caribbean territories. Health practitioners and administrators should maintain a state of readiness with the possibility of tropical cyclones before the official start of the 2024 Atlantic Hurricane Season.
• Food insecurity and associated possible undernutrition would be a concern due to the potential for extensive crop damage and/or loss associated with frequent dry spells across the region. This may be exacerbated in areas where drought is evolving. A similar concern arises as a result of the high flood potential in the Guianas in April or May.
• The occurrence of heatwaves in April or May, and possibly as early as March in some locations, may increase exhaustion during intense outdoor activity and tends to limit labour productivity. It can further increase sweating and water consumption and, during prolonged heatwaves, lead to fatigue, irritability and aggression.
• The occurrence of extreme weather events, impacts and associated alerts may negatively affect mental health. Health Care Professionals are therefore advised to be aware of these issues, as they interact with patients.

This Bulletin provides a broad overview of climate conditions up to 3 months in advance. It is based on insights drawn from CIMH’s suite of technical climate information products and epidemiological insights from CARPHA and PAHO. The information contained herein is provided with the understanding that the CARPHA, the PAHO and the CIMH make no warranties, either expressed or implied, concerning the accuracy, completeness, reliability or suitability of said information. The Bulletin may be freely used and disseminated by the public with appropriate acknowledgement of its source but shall not be modified in content and then presented as original material.