In a recent study published in the Journal of Infection, researchers used data from laboratory diagnostic tests of monkeypox cases. They ran mathematical models to predict how long monkeypox viral deoxyribonucleic acid (DNA) remains detectable in different body fluid samples.
Study: Persistence of monkeypox virus DNA in clinical samples. Image Credit: Studio MIA/Shutterstock
Background
The monkeypox virus, belonging to the genus Orthopoxvirus, was, until very recently, endemic to countries in West and Central Africa. As of August 2022, there have been outbreaks of monkeypox in 99 countries.
Monkeypox presents as mucosal and skin lesions, mainly in the genital, perianal, and oropharyngeal regions, with a high prevalence among men who have sex with men.
Confirmations of monkeypox are based on positive polymerase chain reaction (PCR) tests that detect monkeypox viral DNA in the fluid sample. Although various body fluid samples have been used to detect monkeypox, there is a paucity of information on the stability of viral DNA in these samples. This information could greatly improve the accuracy of clinical diagnostic methods for monkeypox.
About the study
In the current study, researchers used archived laboratory test results to collect molecular screening data, which were grouped according to patients’ age and sex, human immunodeficiency virus (HIV) status, and clinical manifestations of HIV infection. monkey pox.
They used mathematical models such as Weibull parametric regression, log normal and gamma models to estimate the duration over which monkeypox viral DNA could be detected in different types of body fluids. The time to loss of DNA detection was estimated based on the number of days between the onset of symptoms and the first negative PCR test. For samples with equivocal results, the time between the last positive result and the first negative result was considered.
The study included 62 monkeypox cases, of which 23 were urine samples, 19 were swabs from lesions, and nasopharyngeal and rectal swab samples were each 17. Semen, blood, feces, and saliva samples were 16, 15, 14 and 14, respectively. The sample set was made up of 49 men and 13 women, with 51 HIV-negative people.
The clinical manifestations were rashes and skin lesions, fever, lymphadenopathy, myalgia, headaches, chills, and fatigue in decreasing order of reported frequency.
Results
The results of the mathematical model indicated that the persistence of monkeypox viral DNA in body fluids ranged from 5.7 to 13.5 days. Median time was highest for urine samples (13.5 days), followed by semen and blood samples (11.4 and 10.5 days, respectively). Viral DNA was the least persistent in skin lesion samples (median 5.7 days).
The authors discussed some of the limitations of the study. The study did not test the infectivity of viral particles and only investigated the persistence of DNA in fluids. In addition, the date of sample collection could have been different from the date of onset of symptoms. Finally, the authors believe that the persistence time of viral DNA in body fluids estimated in this study might not be generalizable to all monkeypox infections, especially asymptomatic ones.
Conclusions
To conclude, the study investigated the stability of monkeypox viral DNA in various types of body fluid samples from monkeypox patients. The researchers used mathematical models to estimate the time to loss of DNA detection. They found that monkeypox viral DNA was most stable in urine samples, followed by semen and blood samples, and least stable in samples from skin lesions.
The study findings can be used to make clinical testing recommendations for efficient sampling and detection of monkeypox cases. Rapid and accurate tests can improve the initiation of preventive measures such as isolation and medication, thus limiting the transmission of the disease.
Magazine Reference:
Li, Z., Li, XX, Chen, Y., Ruan, Q., Huang, X., Zhu, G., & Sun, J. (2022). Persistence of monkeypox virus DNA in clinical samples. Infection Magazine. do: https://doi.org/10.1016/j.jinf.2022.10.013 https://www.journalofinfection.com/article/S0163-4453(22)00611-9/full text
Source: news.google.com