Mpox Person-to-Person Transmission-Where Have We Got So Far? A Systematic Review

The recent multi-country outbreak of Mpox (Monkeypox disease) constituted a public health emergency. Although animal-to-human transmission is known to be the primary way of transmission, an increasing number of cases transmitted by person-to-person contact have been reported. During the recent Mpox outbreak sexual or intimate contact has been considered the most important way of transmission. However, other routes of transmission must not be ignored. The knowledge of how the Monkeypox Virus (MPXV) spreads is crucial to implement adequate measures to contain the spread of the disease. Therefore, this systematic review aimed to collect scientific data published concerning other implicated sources of infection beyond sexual interaction, such as the involvement of respiratory particles, contact with contaminated surfaces and skin-to-skin contact. The current study was performed using the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Publications analyzing contacts of Mpox index cases and their outcome after contact were included. A total of 7319 person-to-person contacts were surveyed and 273 of them became positive cases. Positive secondary transmission of MPXV was verified after contact with people cohabiting in the same household, with family members, with healthcare workers, or within healthcare facilities, and sexual contact or contact with contaminated surfaces. Using the same cup, sharing the same dishes, and sleeping in the same room or bed were also positively associated with transmission. Five studies showed no evidence of transmission despite contact with surfaces, skin-to-skin contact, or through airway particles within healthcare facilities where containment measures were taken. These records support the case for person-to-person transmission and suggest that other types of contact beyond sexual contact pose a significant risk of acquiring the infection. Further investigation is crucial to elucidate MPXV transmission dynamics, and to implement adequate measures to contain the spread of the infection.