At the initial stage of the outbreak, “the majority of laboratory confirmed cases (2933/3413; 86%) were reported from the WHO European Region. Other regions reporting cases include: the African Region (73/3413, 2%), Region of the Americas (381/3413, 11%), Eastern Mediterranean Region (15/3413, <1%) and Western Pacific Region (11/3413, <1%).  One death was reported in Nigeria in the second quarter of 2022.” On 21 June, Singapore confirmed an imported case, which was also the first in Southeast Asia. Later, on 22 June, South Korea confirmed its first case of monkeypox virus. The Korean citizen, who was tested positive, showed symptoms while entering the country from Germany. On 24 June, “a man in his 20s who had studied in Germany from January until June this year” was also confirmed when he returned to Taiwan, China, according to Reuters. As of 29 June, there are 5115 cases globally across 51 countries, territories, and areas, which are not endemic to the virus, according to the CDC.

Monkeypox is a virus that is generally spread through close or intimate contact with  lesions, body fluids, respiratory droplets and contaminated materials such as bedding, with symptoms that include a rash and fever. In spite of its infectious nature, the R0 value for Monkeypox is only 0.6~1, indicating that it is much less contagious than fast-spreading respiratory diseases like COVID-19 and its emerging Omicon BA.2 variant, which may reach 12, as was calculated by professor Adrian Esterman, chair of biostatistics at the University of South Australia, in March. Thus, Monkeypox causes less severe illness, with its Case Fatality Rate only around 1 to 10 percent in human, compared with the high CFR of the smallpox—monkeypox’s famous cousin that was considered eradicated since 1980—of around 30%, as what Dr. Zhu Huachen, a public health expert from the University of Hong Kong, said in the interview with CGTN’s Yang Zhao on 6 June. Current vaccines for smallpox can also protect against the monkeypox at the effectiveness rate of about 85%. Moreover, Yang Zhao mentioned that the monkeypox is an enveloped double-stranded DNA virus, the structure of which makes it more stable and less likely to evolve over time than RNA virus, such as COVID-19.

Notwithstanding, two things are still worth noting in terms of the outbreak of the monkeypox.

Firstly, Monkeypox, which used to be found mostly in the tropical forests in Africa, is abruptly emerging in many other non-endemic countries. The virus was initially discovered in monkeys in a Danish laboratory in 1958. The first human case was identified in a child in the Democratic Republic of the Congo in 1970. According to the Cleveland Clinic, “In the spring of 2003, the first outbreak of monkeypox outside of Africa occurred in the United States. A shipment of infected animals from Ghana was imported into Texas. The infected rodents spread the virus to pet prairie dogs, which then infected 47 people in the Midwest.” The increasing international travel makes the virus easier to spread around the world. “In the summer of 2021, a case of monkeypox was found in a U.S. resident who had traveled from Nigeria to the United States. Then, 2022 brought outbreaks to regions outside of Africa, including Europe, the Americas and Australia.” However, it was weird that many documented cases had “no known travel links to endemic regions”. Dr. Zhu claimed that “We are not very sure about the virus diversity and its evolutionary pathway. We have no idea why this virus suddenly gained the ability to spread, and now has disseminated to over 20 countries within these 3 or 4 weeks.” She added that “Unlike the smallpox that was only infectious to human, monkeypox is a zoonotic disease.” Therefore, interspecies transmissions will make it much more difficult to fully control and prevent the disease. Some scientists suggested that the mutant strains trigger multiple chains of transmission, which also complicates the tracing problems. On June 3, a spokesperson for the U.S. Centers for Disease Control and Prevention stated at a press conference that the two monkeypox viruses circulating in the United States “are similar to each other, but they are not related to each other.” However, it still remains unknown whether the monkeypox’s unique evolutionary pathway will result in infection in a larger scale. 

Another thing is that a large number of cases clustered around men who have sex with men. According to BBC, on 1 June, “111 of the 183 cases in England are in men who are gay, bisexual or have sex with men.” In the United States, of the 17 initially reported cases, 16 also involved men who have sex with men, and 14 of them had a history of contact with the earliest identified cases. Concern arose as for whether the new monkeypox virus could be sexually transmitted. According to Nidhi Saha, “Some of the monkeypox cases identified during the current outbreak have been reported among individuals infected with the human immunodeficiency virus (HIV), specifically in MSM populations. Moreover, the monkeypox virus was detected in the seminal fluid, as well as genital and rectal lesions, of four MSM patients with monkeypox infection from Italy. Recent clinical evidence supports the probability that sexual transmission of the monkeypox virus has occurred during the current outbreak.” She added that “Although further studies are needed to confirm global speculations, definitive evidence of infectivity is lacking. Nevertheless, viral shedding and its efficiency for sexual transmission have been confirmed.” However, Dr. Zhu Huachen pointed out that the conclusion cannot be obtained yet because of the lack of accurate clinical data to prove how the virus spreads. Is it through sex, skin-to-skin contact, or through shared towels and indirect contact with clothing? In the future, the patient’s semen may be regarded as a vital evidence to confirm the relationship. 

By Jennifer Liu