Headlines on infectious diseases (Sources: Airfinity, Nature, Promed):
Crimean-Congo haemorrhagic fever in several middle Eastern locations, and also posing some threat to Europe, with cases now in Georgia.
Cholera and measles significantly burden African countries while dengue continues to claim lives in Asia and South America.
The outbreak of Lassa fever in Nigeria has been mentioned in previous reports.
Anopheles stephensi, the malaria-spreading mosquito which is resistant to insecticides and well adapted to urban life, has been detected in urban Kenya.
Murray Valley encephalitis in Australia – 14 cases (5 fatal) in 4 Australian states, the most recent one in Western Australia. Australia has also reported some cases of meningitis and an outbreak of Legionnaire’s disease in Melbourne.
On COVID-19:
Difference in mortality between COVID-19 and influenza declined greatly from early in the pandemic to the most recent northern winter, in this US Veterans’ study: https://jamanetwork.com/journals/jama/fullarticle/2803749
In summary, death rates among people hospitalized for COVID-19 were 17% to 21% in 2020 vs 6% in this study, while death rates for those hospitalized for influenza were 3.8% in 2020 vs 3.7% in this study. The decline in death rates among people hospitalized for COVID-19 may be due to changes in SARS-CoV-2 variants, increased immunity levels (from vaccination and prior infection), and improved clinical care. The increased risk of death was greater among unvaccinated individuals compared with those vaccinated or boosted—these are findings that highlight the importance of vaccination in reducing risk of COVID-19 death.
Currently, as reported in YLE, the US is currently at a new low in death rates due to COVID, with overall death rates barely above the pre-COVID rates, whereas at peak, they were almost 50% above (YLE your local epidemiologist).
On a related topic, you may be interested in this large European study GENOMICC which was published by over 2000 authors in Nature, looking at the possible genetic underpinnings of vulnerability to COVID-19. They analysed genomes of over 24000 patients, and found 49 DNA sequences that are associated with becoming critically ill from COVID-19, including 16 which had not been reported previously. https://www.nature.com/articles/s41586-022-04576-6
Turning to the situation with SARS-CoV-2 variants, the three biggest are all at about 25% of new sequences currently, however the context is different: XBB.1.5 is around 25% but rapidly declining; XBB.1.9 lineages are also around 25% but likely to be outcompeted by XBB.1.16 which is increasing rapidly. In the US, the CDC has recommended vaccine specifically targeted to XBB subvariants (Airfinity, YLE)
Other:
A WHO EPI-WIN seminar on MERS-CoV, a circulating coronavirus with epidemic and pandemic potential took place 24 May 2023 and another one on emerging zoonotic diseases is scheduled for 13:00–14:00 CEST (Geneva time) on Wednesday, 31 May. Both will be able to be viewed post-event on the EPI-WIN YouTube channel.
A nested case-control study of US military personnel showed increased incidence of germ cell testicular tumours in pilots and aircraft mechanics compared with other occupations, which has been suggested by some previous studies – although there are some limitations with possible misclassification bias or confounding. Denic-Roberts et al https://oem.bmj.com/content/80/6/312 (if any of you needs the reprint I can email it).
David Powell
IATA Medical Advisor