Transmission (References)

2 August 2022

Lapa D, Carletti F, Mazzotta V, et al. Monkeypox virus isolation from a semen sample collected in the early phase of infection in a patient with prolonged seminal viral shedding. Lancet Infect Dis. 2022 Aug 2:S1473-3099(22)00513-8. PubMed: Full text:

“Semen collected on day 6 after symptom onset was inoculated in Vero E6 cells (ATCC; Manassas VA, USA). Clear cytopathic effect was observed 48 h after the inoculum and monkeypox virus replication was confirmed by real-time PCR on DNA purified from cell growth medium collected after 48 h, 72 h, and 96 h.” The authors conclude that prolonged shedding of monkeypox virus DNA might occur in the semen of infected patients for weeks after symptoms onset.


15 July 2022

Atkinson B, Burton C, Pottage T, et al. Infection-competent monkeypox virus contamination identified in domestic settings following an imported case of monkeypox into the UK. Environ Microbiol. 2022 Jul 15. PubMed: Full text:

Environmental sampling was performed at two adjoining single room residences occupied by a monkeypox case and their sibling. Monkeypox virus DNA was identified in multiple locations throughout both properties, and monkeypox virus was isolated from several samples three days after the patient was last in these locations.


28 June 2022

Schneider KA, Eichner M. Does it matter who is spreading monkeypox? Lancet Infect Dis. 2022 Jun 28:S1473-3099(22)00431-5. PubMed: Full text:

The magic word: awareness. The authors point out that as with smallpox, individuals who are infected with monkeypox take rather long to develop symptoms and they have—compared with influenza or SARS-CoV-2—a rather long infectious period. Therefore, the average generation time of monkeypox is rather long (about 20 days).This renders monkeypox highly vulnerable to interventions: even with R0=3, it would take months until a few thousand cases occur.


27 June 2022

Nörz D, Pfefferle S, Brehm TT, et al. Evidence of surface contamination in hospital rooms occupied by patients infected with monkeypox, Germany, June 2022. Euro Surveill. 2022 Jun;27(26). PubMed: Full text:

The authors examined surfaces of two hospital rooms occupied by monkeypox patients and the adjacent anterooms, which were used for donning and doffing personal protective equipment (PPE). They successfully isolated monkeypox virus from three different samples, each with a total of at least 106 virus copies.


18 June 2022

Miura F, van Ewijk CE, Backer JA, et al. Estimated incubation period for monkeypox cases confirmed in the Netherlands, May 2022. Euro Surveill. 2022 Jun;27(24):2200448. PubMed: Full text:

The authors estimated the monkeypox incubation period (n=18). Mean incubation period was 8.5 days (5th-95th percentiles: 4.2-17.3). Miura et al. estimate the percentage of monkeypox cases that would develop symptoms after the conclusion of 21 days period to be approximately 2%. “These findings suffice for justifying the current use of 21 days for quarantining (or other approaches to avoid infectious contacts).”


31 May 2022

Heskin J, Belfield A, Milne C, et al. Transmission of monkeypox virus through sexual contact – A novel route of infection. J Infect. 2022 Jun 1:S0163-4453(22)00335-8. PubMed: Full text:

The authors report what they “believe to be the first case of MPX [monkeypox] infection with documented transmission through sex.” The case involves two white British men who reported no recent travel outside of the UK and no history of travel to regions with endemic MPX.


24 October 2007

Croft DR, Sotir MJ, Williams CJ, et al. Occupational risks during a monkeypox outbreak, Wisconsin, 2003. Emerg Infect Dis. 2007 Aug;13(8):1150-7. PubMed: Full text:

During the 2003 outbreak in the US, the authors identified 19 confirmed, 5 probable, and 3 suspected cases. Occupationally transmitted infections occurred in 12 veterinary staff, 2 pet store employees, and 2 animal distributors. The following were associated with illness: working directly with animal care (p = 0.002), being involved in prairie dog examination, caring for an animal within 6 feet of an ill prairie dog (p = 0.03), feeding an ill prairie dog (p = 0.002), and using an antihistamine (p = 0.04).


1 March 2005

Fleischauer AT, Kile JC, Davidson M, et al. Evaluation of human-to-human transmission of monkeypox from infected patients to health care workers. Clin Infect Dis. 2005 Mar 1;40(5):689-94. PubMed: Full text:

The authors examined health care worker (HCW) exposure to 3 patients with confirmed monkeypox. Of 81 exposed HCWs, 57 (70%) participated in the study. Among 57 participants, 40 (70%) had > or =1 unprotected exposure. No exposed HCWs had signs and symptoms consistent with monkeypox.