The American College of Cardiology has reported a link between monkeypox and myocarditis.
A 31-year-old male infected with MPX developed acute myocarditis approximately one week following the onset of symptoms, according to a case study published on September 3rd in JACC: Case Reports.
Myocarditis, an inflammation of the heart muscle now commonly associated with COVID, has previously been linked with smallpox, a more aggressive member from the same genus of viruses (orthopoxviral) as MPX.
Lead author, Dr Ana Isabel Pinho, from the department of cardiology at Portugal’s São João University Hospital Centre, said this case suggested that cardiac involvement could be a potential complication associated with MPX infection.
“By extrapolation, the monkeypox virus could have tropism for myocardium tissue or cause immune-mediated injury to the heart,” Dr Pinho said.
“We believe that reporting this potential causal relationship can raise more awareness of the scientific community and health professionals for acute myocarditis as a possible complication associated with monkeypox; and might be helpful for close monitoring of affected patients for further recognition of other complications in the future.
“Further research is needed to identify the relationship between monkeypox and heart injury.”
She explained that the patient presented to a health clinic five days after the onset of symptoms, including malaise, myalgia, fever and multiple swollen lesions on the face, hands, and genitalia, and MPX infection was confirmed with a PCR swab sample of a skin lesion.
The patient returned to the emergency department three days later reporting chest tightness radiating through the left arm and was admitted to an intensive care unit following an initial routine examination with the clinical suspicion of acute myocarditis.
“Initial ECG showed sinus rhythm with nonspecific ventricular repolarization abnormalities and routine laboratory tests revealed elevated levels of C-reactive protein, creatine phosphokinase (CPK), high-sensitivity troponin I and brain natriuretic peptide (BNP), all of which can indicate stress injury to the heart,” Dr Pinho said.
“The results of the cardiac magnetic resonance (CMR) study performed on the patient were consistent with myocardial inflammation and a diagnosis of acute myocarditis.”
The patient was discharged after one week with a full recovery.
Since the new virus was first observed in early May 2022, over 52,000 cases have been confirmed in more than 90 countries, including Australia, where 124 cases have been diagnosed (confirmed and probable).
Thankfully, new research published the same day in Viruses, has shown that the recommended vaccinia virus (VACV)-based vaccines are an effective weapon to combat MPX, including the new strain associated with the outbreak MPXV-2022.
The study, co-led by University of Melbourne Professor Matthew McKay, an ARC Future Fellow and Honorary Professor at the Peter Doherty Institute for Infection and Immunity, undertook genomic testing to find out if the genetic mutations already observed could affect vaccine-induced immune responses for the new strain.
“While we identified a small number of distinct mutations in MPXV-2022, our study more broadly demonstrates that VACV and MPXV-2022 are highly genetically similar in the regions targeted by the immune system through vaccination,” Professor McKay said.
“Based on our analysis, we anticipate that the immune responses generated by VACV-based vaccines will continue to do a good job of recognising and responding to MPXV-2022. Our data lends further support to the use of vaccines being recommended globally for combating the current outbreak.”