GlobalHealth Threats

International SOS recently participated in two significant events: the 18th Conference of the International Society of Travel Medicine (CISTM) in Basel, Switzerland, where the theme was “Dawn of a New Era in Travel Medicine" and the 2023 Global Malaria Congress in Melbourne, Australia. These gatherings took place in person for the first time since the start of the COVID-19 pandemic and brought together numerous travel health professionals from various sectors including governments, non-governmental organisations, academia, and the pharmaceutical and private sectors, creating a platform for comprehensive discussions on the latest development in travel medicine and malaria.

The COVID-19 pandemic has transformed the way we travel and manage travel health risks. At both conferences, the impact of climate change on the resurgence of malaria emerged as a critical challenge. Changes in temperature, rainfall, and humidity greatly influence the lifecycle of the malaria parasite, leading to the disease's expansion into new areas. This is highlighted by the spread of the malaria-transmitting mosquito Anopheles Stephensi, from South Asia and the Arabian Peninsula into Africa. While other malaria mosquitoes primarily breed in rural settings, this mosquito thrives in urban environments and is increasingly resistant to many insecticides.

In addition to climate change, other external factors hinder malaria elimination efforts. Supply chain issues and civil and social unrest impede the distribution of preventive, diagnostic, and treatment measures to the most vulnerable populations. The parasite's increasing resistance to antimalarial medications and the reduced effectiveness of insecticide-treated nets are well-known challenges in the fight against malaria. However, emerging tools in vector control, such as dual-ingredient nets, genetic modification of mosquitoes, and the use of baits, offer potential solutions.

Even though these challenges primarily affect regions with high transmission rates, the risk of infection should be considered by anyone travelling for business or leisure. Malaria remains prevalent in over 80 countries, causing more than 240 million infections annually, including among business and leisure travellers, and international and domestic workforces. Recent data from International SOS shows a concerning trend of increasing requests for assistance related to malaria, with 2022 experiencing a 10% rise compared to 2021. Notably, in 2023, locally-acquired malaria cases have been reported in Florida, USA, and there has been an expansion of malaria transmission in Costa Rica and increased activity in Panama and South Africa.

Vaccines against malaria have been in development for over 50 years. One vaccine, RTS,S (brand name Mosquirix) underwent large-scale international pilot programs since 2015, and in 2021 the World Health Organization recommended its use in children in moderate-to-high malaria transmission areas. Another vaccine, known as R21, has shown high efficacy against the disease in clinical trials in the UK, Thailand and several African countries. If approved, this vaccine could help meet the gap between supply and demand for vaccines and help with further reductions in child illness and deaths. While progress has been made in the development of malaria vaccines, no vaccine is currently available for travellers.

In the absence of widely available vaccines, seeking pre-travel advice about malaria prevention cannot be overemphasised. The “A, B, C, D, E” of prevention is still critical. Studies consistently indicate that individuals who do not obtain such advice are at higher risk of contracting malaria. Leisure travellers visiting friends and relatives are particularly prone to neglecting pre-travel advice, including taking chemoprophylaxis and adhering to preventive measures. Therefore, organisations must assess malaria risks for their travellers and implement comprehensive measures to protect them. These measures should include education and awareness campaigns, pre-travel medical reviews, provision of preventive supplies, and ensuring access to rapid diagnosis and treatment. Organisations operating in malaria-endemic areas should also incorporate vector-control strategies into their malaria control programs.