Wednesday, January 12, 2022

Post-infectious body odor

Every infection has a distinct odor. It could be associated with changes in the gut microbiome. Besides, circulating B-cells from our immune system are also producing chemical odors that appear after viral infection. T-cell and cytokine involvement is also possible. Infections can change body odor for the worse.  PATM or MEBO conditions could begin after an infection and linger thereafter.  

COVID-19 is known to be associated with a specific odor.  Early studies identified volatile compounds that discriminated COVID-19 from other conditions. Some of these compounds - such as fruity smelling ketones - are also associated with diabetes - a risk factor for Severe COVID-19 infection. Another compound, Heptanal, associated with lung cancer, can also predict the severity of the Coronavirus disease.

Dogs (and rats and other animals) can easily detect the smell of COVID-19. They are already helping during this pandemic - Massachusetts schools, for example, are using dogs to sniff out Covid-19. The dogs come to the schools weekly and work to detect cases in empty classrooms, auditoriums, cafeterias and gymnasiums, If Covid is detected, the authorities tell the health nurse who relays the information to the people affected.

Long COVID - when people continue to have symptoms of COVID-19 for months after their initial illness. - has a distinct smell as well. A paper posted today on MedRxiv tells that dogs can easily detect long COVID as well - in at least half of the cases. 

Between May and October 2021, 45 Long COVID patients sent their axillary sweat samples to the National Veterinary School of Alfort. Average age of the patients was 45 (6-71) and 73.3% were female. No patient had been admitted in intensive care unit during the acute phase. Prolonged symptoms had been evolving for an average of 15.2 months (range: 5-22). Main symptoms of prolonged phase were intense fatigue (n=37, 82.2%), neurocognitive disorders such as concentration and attention difficulties, immediate memory loss (n=24, 53.3%), myalgias/arthralgias (n=22, 48.9%), cardiopulmonary symptoms (dyspnea, cough, chest pain, palpitations) (n=21, 46.7%), digestive symptoms (diarrhea, abdominal pain, reflux, gastroparesis...) (n=18, 40.0%), ENT disorders (hyposmia, parosmia, tinnitus, nasal obstruction, inflammatory tongue, dysphonia, sinusitis) (n=18, 40.0%) (table 1). 11 (24.4) patients had at least one positive SARS-CoV-2 serology before any vaccination, 29 (64.4%) had a negative SARS-CoV-2 serology and 5 (11.1%) had no serology results. Snapshot of the table shows some of the cases. Interestingly, patients with odor exhibited symptoms similar to long COVID sufferers in the MEBO community. This includes loss of smell and heart palpitations. 


REFERENCES


Dominique GRANDJEAN, Dorsaf SLAMA, Capucine GALLET, Clothilde JULIEN, Emilie SEYRAT, Marc BLONDOT, Maissa BENAZAZIEZ, Judith ELBAZ, Dominique SALMON Screening for SARS-CoV-2 persistence in Long COVID patients using sniffer dogs and scents from axillary sweats samples  medRxiv 2022.01.11.21268036; doi: https://doi.org/10.1101/2022.01.11.21268036

Tuesday, January 4, 2022

Worried about body odor?

You are not alone. According to pre-COVID surveys, over one third said the fear of smelling unpleasant left them feeling unhappy and unattractive. Many people who survived COVID-19 worry about their body odor getting worse post-infection.

A team of researchers from Virginia Commonwealth University surveyed 322 individuals with loss of smell or taste as a result of confirmed COVID-19 infection and found that about half of them felt depressed and worried about their body odor [Coelho et al., 2021].  Extrapolating results of other surveys, this translates into about 20% of those who got through COVID-19.  

The most frequently reported phantom smell (likely not actually there) is the odor of smoke or burned food [Frasnelli et al, 2004]. Interestingly, these are also the most frequently reported types of smells that long-COVID sufferers can't perceive, when others detect them. 

Temporary loss of smell is common. About 20% of population experience it sometime before the age of 75. This number increases to ~80% in older age. 

Loss of smell associated with viral infections, especially COVID-19 is much more prevalent. Sometimes it's the only symptom associated with this infection. A meta-analysis of published reports reveals that the overall prevalence of alteration of the sense of smell or taste following COVID-19 infection ranges between 31% and 67% in severe and mild-to-moderate symptomatic patients, respectively. Fortunately, in most (70-80%) cases it comes back in 6 month or longer. A higher recovery rate was highlighted for subjects who underwent influenza vaccination. 

REFERENCES

Coelho DH, Reiter ER, Budd SG, Shin Y, Kons ZA, Costanzo RM. Quality of life and safety impact of COVID-19 associated smell and taste disturbances. American Journal of Otolaryngology. 2021 Jul 1;42(4):103001.

Frasnelli J, Landis BN, Heilmann S, Hauswald B, Hüttenbrink KB, Lacroix JS, Leopold DA, Hummel T. Clinical presentation of qualitative olfactory dysfunction. European Archives of Oto-Rhino-Laryngology and Head & Neck. 2004 Aug;261(7):411-5. 

Maiorano E, Calastri A, Robotti C, Cassaniti I, Baldanti F, Zuccaro V, Stellin E, Ferretti VV, Klersy C, Benazzo M. Clinical, virological and immunological evolution of the olfactory and gustatory dysfunction in COVID-19. American Journal of Otolaryngology. 2022 Jan 1;43(1):103170.

Vaira LA, De Vito A, Lechien JR, Chiesa‐Estomba CM, Mayo‐Yàñez M, Calvo‐Henrìquez C, Saussez S, Madeddu G, Babudieri S, Boscolo‐Rizzo P, Hopkins C. New onset of smell and taste loss are common findings also in patients with symptomatic COVID‐19 after complete vaccination. The Laryngoscope. 2021 Nov 26.