Sunday, March 05, 2023

India: Media Reports Of A Large Surge In Pediatric Adenovirus Infections

 https://www.cdc.gov/adenovirus/index.html

#17,329

With the strong caveat that the Indian press often leans towards the sensational when it comes to coverage of influenza, and other infectious diseases - and many past stories have turned out to be overblown (see here, here, and here) - there are persistent reports of a large surge in Adenovirus infections affecting several areas of India, but most severely in West Bengal

Overnight, CNBC carried the headline (based on reporting from IANS):

Other headlines from the Indian press suggest even higher numbers of pediatric fatalities, although local health departments have released far lower numbers.   

Adenovirus: West Bengal reports over 40 deaths among children


On Thursday West Bengal Chief Minister Mamata Banerjee downplayed these reports, and stated there was `no evidence of a viral epidemic at present' and stressed their ability to deal with the situation.  Meanwhile, the media reports continue. 

There are dozens of serotypes of adenovirus, but the CDC classifies the ones of greatest importance as:
  • Adenovirus types 3, 4 and 7 are most commonly associated with acute respiratory illness.
    • Adenovirus type 7 has been associated with more severe outcomes than other adenovirus types, particularly in people with weakened immune systems. In the last 10 years, instances of severe illness and death from adenovirus type 7 infection have been reported in the United States.
  • Adenovirus type 14, which since 2007 has been associated with outbreaks of acute respiratory illness among U.S. military recruits and the general public
  • Adenovirus types 8, 19, 37, 53, and 54, which can cause epidemic keratoconjunctivitis
  • Enteric adenovirus types 40 and 41, which cause gastroenteritis, usually in children
  • Some adenoviruses (e.g., 4 and 7) that spread in bodies of water such as small lakes or swimming pools without adequate chlorine and can cause outbreaks of febrile disease with conjunctivitis
The most detailed report I've found on India's current outbreak comes from ABP Live, which published an interview yesterday with Dr Prabhas Prasun Giri from the Institute of Child Health in Kolkata who described the outbreak as primarily adenovirus 7 and 3, but also mentions a potential new recombinant 7/3 virus. 


         (Excerpt)

Dr Prabhas Prasun Giri, associate professor and PICU (paediatric ICU) in-charge at Institute of Child Health in Kolkata, said genomic sequencing has revealed that the adenovirus serotype 3, 7 as well as a new 7/3 recombinant strain were found in most cases in Bengal.

          (Continue . . . )

Adenoviruses are typically grouped with `lesser' seasonal respiratory viruses - like rhinoviruses, respiratory enteroviruses, parainfluenza (1-4), and metapneumonia viruses -  and are not `reportable' to the CDC.  

As a result we don't have a good handle on how often outbreaks occur.  We do, occasionally, learn of outbreaks, including:

Now that a coronavirus has shown that it can - under the right conditions - spark a severe pandemic, researchers are taking a closer look at the pandemic potential of these `lesser' viruses. 

One such report was published just last month.

This is a scenario that was also addressed in 2021 in an article in PloS Pathogens (see What is the risk of a deadly adenovirus pandemic? by Eric J. Kremer). 

While adenoviruses are admittedly pretty far down our list of pandemic concerns, the coronavirus pandemic proves that `lesser' viruses can sometimes  surprise us.   

As far as the outbreak in India is concerned, we'll have to wait for more details, particularly on the reported discovery of a recombinant 7/3 adenovirus. 

Stay tuned.