And the first covid breathalyser has been approved in the US.
Welcome to The Medical Republicâs Covid Catch-Up.
Itâs the latest covid news in one convenient post. Email bianca@biancanogrady.com with tips, comments or suggestions.
19 April
- Drop in chlamydia diagnoses in the US in 2020 likely the result of reduced screening and testing.
- First covid breathalyser approved in the US.
- Third vaccine dose brings most blood cancer patients’ antibodies up to adequate levels.
A 13% drop in the number of chlamydia cases diagnosed during 2020 in the United States is actually bad news, with experts suggesting it’s the result of reduced testing and screening rather than a true decline in incidence.
In contrast to the drop in chlamydia cases, the US Centers for Disease Controlâs latest report on STI surveillance â covering the first year of the pandemic â reported a 10% increase in gonorrhoea and 7% increase in syphilis by the end of 2020 compared to 2019. Of even greater concern was the 24% rise in the rates of syphilis among reproductive-aged women, and a 15% increase in congenital syphilis.
The reportâs authors suggested that while gonorrhoea and syphilis symptoms were generally hard to ignore â and hence more likely to drive people to get tested â chlamydia was mostly asymptomatic and only detected through screening.
âTherefore, it is likely chlamydia was disproportionately affected by reduced screening during the pandemic, resulting in undiagnosed infections,â they wrote, raising concerns that delayed diagnoses and treatment could impact future rates of pelvic inflammatory disease and infertility.
The first covid breathalyser, which detects five volatile organic compounds associated with SARS-CoV-2 infection and delivers results in a few minutes, has been granted emergency use authorisation in the US.
According to the US Food and Drug Administration, in a trial of more than 2400 people, the test accurately diagnosed 91% of positive cases â both symptomatic and asymptomatic â and accurately ruled out 99% of negative cases. The results were similar for the Omicron variant.
The test has to be performed by a trained operator, and the instrument is the size of a small suitcase.
A third dose of mRNA vaccine boosts antibody levels in most patients with haematological malignancies to the same level as a second dose in healthy individuals, a study has found.
A non-peer-reviewed preprint study published on MedRxiv looked at the levels of SARS-CoV-2 antibodies in a prospective cohort of 584 patients with haematological cancers who were immunocompromised and who received three doses of an mRNA covid vaccine.
Researchers saw that after two doses of vaccine, only around half the participants had adequate antibody levels and nearly one-third did not seroconvert at all.
But after a third vaccine dose given five months later, nearly 79% seroconverted, and just under two-thirds achieved adequate neutralising antibody levels.
The main exceptions were patients with B cell non-Hodgkinâs lymphoma being treated with rituximab, those undergoing CAR T cell therapy and CLL patients treated with ibrutinib, whose antibody levels remained low despite the third dose of vaccine.
The authors noted that these patients might still have generated potent T cell responses to vaccination, which has been seen in patients with rheumatological or haematological conditions.
âCovid-19 vaccination in immunocompromised patients should be based on a primary 3-dose mRNA-1273 schedule instead of the 2-dose schedule that is standard for healthy individuals,â they wrote.
