From Airfinity’s curated analysis of various health and media sources and from the ECDC (European Centre for Disease Prevention and Control) Weekly Communicable Disease Threats Report:
- The outbreak of highly pathogenic avian influenza (HPAI) A(H5N1) in cattle is still ongoing, with 69 farms affected across nine states of the US.
- As of today, there have been three human cases of avian influenza A(H5N1) reported in workers at US dairy farms with infected cows.
- No meat from affected dairy cows has entered the food supply.
- To date, routine population-based surveillance has not detected any increase in community rates of respiratory infections.
- Hospitals in the US are no longer required to report COVID-19 hospitalisations. Meanwhile, reported COVID-19 oral antiviral uptake and COVID-19 hospitalisations correlate well with SARS-CoV-2 wastewater concentration, indicating that wastewater can provide suitable metrics.
- There has been a global post COVID-19 pandemic resurgence of pertussis, also known as whooping cough. Pertussis is caused by a highly contagious bacterium and typically has a cyclical pattern returning every 3 to 5 years, varying by country. Whooping cough is preventable with a 3-dose vaccine (which also includes diphtheria and tetanus) given to small children, but recent vaccine hesitancy has resulted in an unexpected comeback of the disease. Since vaccine coverage is lowest in Africa and Oceania, these continents could be at highest risk.
- Measles cases have been detected in at least 118 countries worldwide since the start of the year. According to the US CDC, travellers to areas where measles has been surging are at risk if they have not been fully vaccinated at least two weeks prior to departure or have not had measles in the past. The majority of measles cases imported into the US have occured in unvaccinated residents who became infected during international travel.
- Thirteen cases of invasive meningococcal disease (IMD) serogroup W have been reported from France, Norway, UK, and US. The cases are epidemiologically linked to religious practices in the Umrah zones in the Kingdom of Saudi Arabia (KSA). International spread of IMD associated with mass gatherings during pilgrimages in the KSA has been reported in the past. Vaccination against meningococcus is recommended for those travelling to KSA to perform Umrah and for Hajj pilgrims – this year, the annual Islamic Hajj pilgrimage will take place between 14 and 19 June.
- Mpox is increasing again in the US since April, New York City and Illinois being among the most affected areas; these cases are caused mainly by Clade II, the less severe strain.
- Since the beginning of 2024, over seven million dengue cases have been reported globally. The map below shows the regions where cases have been reported between February and April of this year.
A selection of articles of interest:
Another three documents that have also been published by the WHO in the last few weeks:
- The “Global technical consultation report on proposed terminology for pathogens that transmit through the air” puts forward a new WHO definition of disease spread through air. The document is available here: https://cdn.who.int/media/docs/default-source/documents/emergencies/global-technical-consultation-report-on-proposed-terminology-for-pathogens-that-transmit-through-the-air.pdf?sfvrsn=de07eb5f_1&download=true
Almost 500 experts contributed to the definition, including physicists, public health professionals and engineers, many of whom disagreed over the topic in the past. The document concludes that the descriptor "through the air" can be used for infectious diseases where the main type of transmission involves the pathogen either travelling through the air or being suspended in the air. Under the umbrella of ‘through the air’, two descriptors can be used:
- ‘Airborne transmission/inhalation’: When IRPs (infectious respiratory particles) expelled into the air enter, through inhalation, the respiratory tract of another person and may potentially cause infection. The distance travelled depends on multiple factors including particle size, mode of expulsion and environmental conditions such as airflow, humidity, temperature, setting, ventilation.
- ‘Direct deposition’: When IRPs expelled into the air follow a short-range semi-ballistic trajectory, then are directly deposited on the exposed facial mucosal surfaces (mouth, nose or eyes) of another person, thus entering the human respiratory tract; this is very similar to the existing descriptor ‘droplet transmission’ but, importantly, without specifying any particle size.
- The WHO “Technical brief on designation of points of entry under the International Health Regulations (2005)” https://iris.who.int/bitstream/handle/10665/376842/B09038-eng.pdf . There are three types of PoEs (points of entry): international airports, ports and ground crossings. By designating PoEs national authorities can prioritize and direct limited public health resources. In this document you will find criteria, factors and characteristics influencing PoE designation. A communication link with conveyance operators is one of the core capacity requirements of PoEs.
- Finally, also just published by the WHO: “Syndromic entry and exit screening for epidemic-prone diseases of travellers at ground crossings” https://www.who.int/publications/i/item/9789240090309 . Syndromic entry and exit screening for fever and/or respiratory, gastrointestinal or haemorrhagic fever symptoms, using one or more methods such as temperature checks, observation and health declaration forms, has been conducted at ground crossings over decades for some epidemic-prone diseases such as Ebola and other viral haemorrhagic fevers, SARS-CoV and other respiratory infections, as well as plague. Whether this type of screening is an effective means of controlling the spread of epidemic-prone diseases has been repeatedly called into question. This WHO-commissioned review concludes that there is presently insufficient evidence to develop an evidence-based guideline for or against syndromic entry and exit screening of travellers at ground crossings; this document is therefore essentially a call for research.
- Exciting news on malaria prophylaxis – Still early research days, but subcutaneous administration of a monoclonal antibody has been demonstrated to protect both adults against controlled Plasmodium falciparum infection in a phase 1 trial, and 6-10 year-old children over a 6-month malaria season: https://www.nejm.org/doi/exam/10.1056/NEJMoa2312775 . Stand by for developments in this line of research. Perhaps monoclonal antibodies may become, in the not so distant future, a relevant tool for malaria prevention in travellers.
Events:
Lisbon, Portugal:
- ICAM 2024 International Congress of Aerospace Medicine, October 3rd-5th – early bird deadline is July 31st: www.icam2024.com
- Aviation Health Conference, October 7th-8th – programme here: https://quaynote.com/conference/aviation-health-conference-24/
Dr Rui Pombal
IATA Medical Advisor