Insights from a Brazilian study on prolonged Monkeypox (Mpox) virus shedding in the eyes
Charles Tee Fact checked by:Thailand Medical News Team Sep 03, 2024 1 week, 5 days, 19 hours, 32 minutes ago
Medical News: A recent study conducted by researchers from the Federal University of São Paulo, the University of São Paulo, and Weill Cornell Medicine sheds light on the prolonged presence of monkeypox virus (MPXV) in ocular fluids, a finding that has significant implications for both clinical practice and public health. This
Medical News report explores the key findings of this study, which delves into the viral dynamics within the eyes of monkeypox patients and the potential for ongoing transmission through ocular fluids.
Insights from a Brazilian study on prolonged Monkeypox (Mpox) virus shedding in the eyes
Understanding Monkeypox and Its Ocular Manifestations
Monkeypox, also known as MPOX, is a zoonotic disease caused by the monkeypox virus. Typically, the disease is self-limiting, with symptoms lasting 2 to 4 weeks, including fever, rash, and lymphadenopathy. However, complications such as pneumonitis, encephalitis, keratitis, and secondary bacterial infections can occur. Notably, the study focuses on the ophthalmologic involvement in monkeypox cases, particularly the occurrence of keratitis and uveitis, which can sometimes lead to persistent corneal scarring.
The term monkeypox-related ophthalmic disease (MPXROD) was introduced by Kaufman et al. to describe the ophthalmic manifestations associated with monkeypox.
https://jamanetwork.com/journals/jamaophthalmology/fullarticle/2797919
Persistent MPXROD has already been described in cases lasting up to eight months after the onset of monkeypox.
The Study Design and Methodology
In this prospective study, researchers evaluated five confirmed monkeypox patients with ocular symptoms. These patients were referred to the Ophthalmology Department of the Federal University of São Paulo between August and December 2022. The study's primary objective was to assess viral clearance and replication in ocular samples through Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) and viral culture. The researchers also tested for the presence of herpesviruses to rule out other potential causes of ocular disease.
Ocular samples were collected from the patients during their first ophthalmologic evaluation and follow-ups. These samples included swabs of tears, ocular discharge, and the conjunctival cul-de-sac. Aqueous humor paracentesis was performed in two patients. All samples were tested for MPXV and herpesviruses at the São Paulo Tropical Medicine Institute. The researchers also performed MPXV genome sequencing on one ocular sample.
Key Findings: Prolonged Viral Shedding in Ocular Samples
The study revealed several critical findings regarding the viral dynamics of MPXV in the eyes:
-Duration of Viral Shedding: MPXV was detected in ocular samples from all five patients for e
xtended periods, ranging from 19 to 145 days after the onset of systemic symptoms. This prolonged shedding of replication-positive, potentially infectious virus is a significant departure from previous understandings of the disease.
-Viral Replication: The study confirmed the replication of MPXV in ocular samples collected between day 19 and day 145 after the onset of ocular symptoms. This finding indicates that the virus can remain active and potentially transmissible for an extended period.
-Co-Infection with Epstein-Barr Virus: In one patient, the researchers identified co-infection with Epstein-Barr virus (EBV) in ocular surface samples. This patient displayed severe intraocular inflammation and MPXV isolation in the aqueous humor culture. The presence of EBV as a co-pathogen raises questions about its role in exacerbating ocular inflammation in monkeypox cases.
-Virus Classification: MPXV genome sequencing of an ocular sample from one patient classified the virus as belonging to lineage B1 in clade IIb. This classification aligns with the current outbreak's dominant strain.
Implications for Public Health and Clinical Practice
The study's findings have far-reaching implications for both public health and clinical practice:
-Potential for Ongoing Transmission: The prolonged shedding of MPXV in ocular fluids suggests that patients with ocular manifestations of monkeypox may continue to be infectious even after the resolution of systemic symptoms. This finding underscores the importance of extended monitoring and precautions in cases of monkeypox with ocular involvement.
-Infection Control Measures: The ability of MPXV to replicate and remain infectious in ocular fluids for prolonged periods highlights the need for stringent infection control measures. Healthcare providers should be aware of the potential for ocular transmission and take appropriate precautions, particularly in settings where vulnerable individuals may be exposed.
-Impact on Treatment Strategies: The study raises questions about the timing and efficacy of antiviral treatments for MPXROD. In this case series, tecovirimat treatment was initiated relatively late in the course of the illness, and while patients showed improvement, some developed deep corneal scars and experienced visual impairment. The optimal timing for antiviral treatment in ocular disease remains unclear, and further research is needed to determine the best approach.
Conclusion
In conclusion, this study provides valuable insights into the prolonged viral persistence and potential infectivity of monkeypox virus in ocular fluids. The findings challenge the current understanding of the disease and have significant implications for public health and clinical practice. Further research with larger sample sizes and standardized protocols is essential to gain a more comprehensive understanding of viral clearance in viral diseases and to inform effective outbreak management and prevention strategies.
The study findings were published on a preprint server and is currently being peer reviewed.
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4617048
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Read Also:
https://www.thailandmedical.news/news/up-to-10-percent-of-mpox-infections-could-end-up-in-blindness
https://www.thailandmedical.news/news/monkeypox-mpox-can-cause-a-variety-of-eye-issues-that-can-result-in-vision-loss
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