Human coronaviruses (HCoVs), that is, the ones that circulate all the time, not the ones that spill over from an animal host to cause havoc and mayhem, come in four flavours….

• HCoV-229E
• HCoV-OC43
• HCoV-NL63
• HCoV-HKU1

On the back of my last post, I thought I’d start listing what HCoVs do among those with some pre-existing disease or condition.

Generally speaking, the HCoVs circulate spasmodically; each peaking every couple of years and then often in small numbers, at least as far as the relatively limited diagnostic testing conducted reveals.

Clinical studies that include virus testing and with a focus on comorbidities seem rare, as are studies focusing on older age groups using PCR to screen for an extended panel of respiratory viruses (beyond the “standard” eight or so viruses).

Some findings below….

1. Gaunt and colleagues noted in 2010 that 229E was over-represented among the immunosuppressed compared to other HCoVs and respiratory viruses in general. 
2. El-Sahly and colleagues noted in 2000 that 13/16  HCoV antibody detections occurred among inpatients > 35 years of age. Of those infected with an HCoV or a rhinovirus in this age band, 73% had underlying cardiopulmonary disease
3. Cabeca and colleagues noted in 2012 that of the 5/394 mostly paediatric inpatient samples testing positive for a HCoV, 4 (80%) had a comorbidity
4. We noted in 2012 that in 13/61 (21.3%) HCoV-positive cases, chronic underlying disease or immunocompromise was noted. Most (69%) tested positive for OC43
5. Lau and colleagues noted in 2006 that among the 13/4181 samples from mostly child inpatients testing positive for HKU1, 8 (61.5%) had underlying diseases
6. Garbino and colleagues noted in 2006 that among 29/540 adult bronchoalveolar lavage samples testing positive for an HCoV (69% male), 14 (48%) had a comorbidity
7. Kuypers and colleagues noted in 2007 that among 66/1043 children positive only for an HCoV, they were more likely to have a comorbidity than children with coinfections
8. Al Hajjar and colleagues noted in 2011 that among 4/489 specimens (0.8% of samples) from paediatric patient samples in the Kingdom of Saudi Arabia that tested positive for NL63, all had an underlying condition.

This snapshot of studies indicates that HCoVs do not contribute to a large number of severely symptomatic cases, similar to MERS-CoV. However, the literature does focus on studies of HCoVs among those patients with pre-existing or underlying conditions, with age not being limited to those over 50 years.

The search continues. Feel free to add any papers to this list in the comments for this post. I’m also looking for papers studying older populations.

*Imported Post

1. This post from 28JUL2013 was posted over on my old blog platform virologydownunder.blogspot.com.au. It has now been moved here with light editing to improve format, grammar and typos.