Monkeypox has resurfaced recently, with outbreaks occurring in non-endemic countries, creating a worldwide public health emergency (Conger, 2022). These outbreaks have brought contemporary public health concerns in the United States, and new fears to a public still recovering from the siege of SARS-CoV2. Awareness and understanding of the monkeypox virus have been limited in the public, as they have grown numb to the threats of infectious disease because of pervasive assaults from the 2020 Covid-19 pandemic. Monkeypox slipped into mainstream public knowledge in May of this year with the first case in the U.S. reported on May 18 in Massachusetts (Assistant Secretary for Public Affairs [ASPA], 2022).
Because of the associated stigmatism and other negative connotations from online language throughout this year, the World Health Organization (WHO) (2022d) has officially adopted mpox as the preferred term for the disease, a decision made after careful consultation and stakeholder input. For the next year, mpox will be used interchangeably with monkeypox, with the goal of phasing out the term monkeypox completely. The Centers for Disease Control (CDC) (2022a) is currently working to align their website pages with this terminology change, as indicated in an alert box at the top of every page related to the mpox infection. The remainder of this informational review will refer to the disease as mpox.
This work will present an overview of mpox that will cover a brief history of the disease, public health policy, and future projections. Further review will provide insight on the endemic nature of mpox, herd immunity potential, and will indicate the current stance on the disease as an epidemic, a pandemic, or as a well-mitigated viral infection with limited reach and impact. Finally, the chain of infection, vulnerable populations, and current treatment recommendations and options will be presented.
History of Mpox
According to WHO (2022b), mpox was first discovered in humans in 1970, in the Democratic Republic of the Congo, despite the eradication of smallpox taking place in 1968. Since the 1970 case, the mpox virus has been found in 11 African countries, and there was an outbreak in 1996-1997 in the Congo, and in 2017 in Nigeria. The disease traveled outside of Africa in 2003, when an outbreak took place in the United States where 70 cases were reported, said to have originated from imported rodents from Africa. The disease has since spread to Israel and the United Kingdom in 2018, 2019, 2021, and 2022, and to Singapore in 2019. In 2020 and 2021, the disease had returned to the United States, before the most recent outbreak in May 2022 involving multiple nonendemic countries (WHO, 2022b). The WHO declared the mpox outbreak to be an international public health emergency on July 23 (Conger, 2022; Huang, et al., 2022) and the US Department of Health and Human Services (USDHHS) declared mpox in the US to be a public health emergency on August 4, 2022 (Conger, 2022; Philpott, et al., 2022).
A review of multiple resources informs that the infective agent of mpox is a non-variola Orthopoxvirus, a zoonotic virus with a reservoir of unknown origin (Huang, Mu, & Wang, 2022). Figure 2 reflects the chain of infection using data retrieved from WHO (2022a). According to WHO (2022a) the portal of exit, mode of transmission, and portal of entry include direct or intimate contact with an infected human or animal or through respiratory droplets; close, personal, or skin-to-skin contact with material from skin lesions, scabs, saliva, mucus, or upper respiratory secretions; or by touching the genitals, anus, rectum, or vagina. Additionally, mpox can be transmitted by intimate contact through hugging, massage, kissing, prolonged face-to-face contact, or oral, anal, or vaginal sex, and can be spread to the fetus during pregnancy.
Endemic Countries
Although all countries are currently on alert for the mpox outbreak, it is endemic to at least 10 countries in Africa (WHO, 2022b). In June, the recent outbreak was found to include 27 non-endemic countries that had confirmed cases of mpox (WHO, 2022b). According to Conger (2022), by late August, 91 countries that previously did not report any cases, reported current cases, and each of the 50 United States had reported at least one case.
Current Status of Mpox
Currently, mpox is not a pandemic, but concerns are heightened related to the outbreak of mpox in non-endemic countries that began May of this year. According to the CDC (2022a), in mid-September there were nearly 58,000 confirmed cases, in more than 90 countries and territories.
As reported by Phillpot, et al. (2022), the data collected on the cases in the United States from this year suggest that gay, bisexual, and men that have sex with other men make up most of the infections (99%) and racial and ethnic minority groups this population are disproportionately affected (para.1). Of the 99%, 94% reported recent male-to-male intimate contact. The recent outbreak in the US began in May and was declared an outbreak in the first week of August. Enhanced surveillance then began with detection and reporting of cases.
Nearly one-fifth of the infections were travel-associated, and three-fourths were acquired locally (Philpot, et al., 2022). Outside of the United States, this virus has been of global importance since 2017 when Nigeria had an outbreak, and it then spread to Israel, the United Kingdom, and Singapore, before coming to the United States (Silenou, et al., 2020). In 2022, several cases of mpox with no epidemiological link to imported animals or travel have been identified in multiple countries.
Public Policy
After the first known case in May, the USDHHS initiated a response to increase vaccine stock, availability, testing for the virus, treatment options, and public awareness and education (ASPA, 2022). WHO (2022b) supported information sharing early on with this outbreak and the incident response system was activated to collaborate and share case findings, clinical management practices, infection control and prevention measures, and isolation practices.
The WHO is bound by International Health Regulations, which established criteria that must be met to decide if an outbreak represents an international health emergency (Ghebreyesus, 2022). The criteria include reviewing data provided by countries, 3 components that are required for declaring a public health emergency, the advice from the emergency committee, scientific principles and evidence, and finally the risk to human health, spread of the contagion, and risks for impacting international travel (Ghebreyesus, 2022). The risk was high in European regions, but moderate globally (Ghebreyesus, 2022).
Future Projections
Based on the November basic reproduction number calculated on the CDC (2002c) website, it is expected that the incidence of mpox infections in the US will continue to decline, as the R0 number has been less than one since the end of July this year. There could be several reasons that the infection rate is declining, but it is difficult to determine which factors had the greatest impact. It may be that behaviors have changed, vaccinations, or simply that there is an increase in the infection-acquired immunity at this point (CDC, 2002c).
The future is geared toward development of an mpox vaccine, (WHO, 2022d). Philpott, et al. (2022) suggested that public health direct efforts to prioritize men who have sex with men, whether gay, bisexual, or other, as well as those who are affected disproportionately. This effort should include addressing health equity and offering increased testing and prevention services. Additionally, they wanted to minimize the stigma associated with mpox and the population most effected by the disease, which the WHO (2022d) and CDC (2022a) have started to work on with the name change and upcoming change to the ICD-10 code identifying the disease as mpox. The current assessment by WHO (2022b) places us at a moderate risk globally.
Herd Immunity
Herd immunity does not comprehensibly apply to this disease. Although it is true that anyone can host the virus and be stricken with the infection, there are distinct risk factors that are known to increase an individual’s risk. It can then be presumed that avoiding those risk factors will provide sufficient protection from the disease at this time. There is just not enough of the population immune to the infection, to protect those who are vulnerable. As for those seeking vaccination, there are criteria that must be met to determine eligibility; this will be addressed in greater detail later in this report. If the mpox virus begins to mutate rapidly, increases in virulence, or if transmission modes change or increase, expansion of the eligibility requirements for vaccination may be warranted.
Chain of Infection
Conger commented in her 2022 article, how the “longest documented chain of infection” was only six people (para. 3). This makes it seem as though transmission of the virus from one person to another is not a common occurrence, which is likely. Transmission rates are higher in men who have sex with men, and highest among those who have close contact through sexual activity, with one or more lesions on the skin or in the mucous membranes of someone with the infection (CDC, 2022b). An overview of the epidemiological triad is represented in Figure 1.
Figure 1
Epidemiologic Triad for Monkeypox
If any aspect of the chain of infection is broken, the outcome will improve. For a visual representation of mpox chain of infection, see Figure 2.
Figure 2
Chain of Infection for Monkeypox
The incubation period is the time from infection to the onset of symptoms, and there were variances in the incubation period across multiple references. Sources suggested an incubation period of several days, up to a few weeks. The Maine Center for Disease Control & Prevention (MeCDC) (n.d.) indicated an incubation period of three to 17 days, while Huang, et al., (2022) indicated an incubation period of five to 21 days.
According to WHO (2022a), the incubation period is “usually from 6 to 13 days but can range from 5 to 21 days” (para. 10). They have also divided the infection into an invasion period, which lasts from zero to five days, and the skin eruption period, which begins within one to three days of fever onset. The symptoms of the infection can last from two to four weeks, but illness can last longer if complications arise including pneumonia or encephalopathy. Ultimately, a person with the virus can spread it to others starting with onset of symptoms, through complete epithelialization or healing of the rash (CDC, 2022a).
Vulnerable Populations
Relating to the causation, there are identifying factors that place some at a higher risk than others, but these factors are unrelated to race, age, gender, religion, marital status, or family background. They are currently associated with occupation as a healthcare worker caring for an infected person, and as a sex worker. Personal choices for intimate activities, number of partners and frequency can also be sources of increased risk (MeCDC, n.d.).
Vulnerable populations consist primarily of those engaging in riskier sexual behaviors including multi-partner sex, unprotected sex, and/or anonymous sexual partners or sex with someone engaging in sexual relations with someone previously mentioned (MeCDC, n.d.).
Current Treatment Recommendations and Options
There is no direct or specific treatment for mpox currently. Symptom management and prevention from spreading the virus seem to be the primary focus for care of an infected individual. Symptoms, symptom management, antiviral treatments, prevention of spread, and vaccination options will be discussed in this section.
Symptoms
Mpox can present with several symptoms including fever, chills, headaches, muscle aches, backaches, swollen lymph nodes, exhaustion, itching, pain or sores in mouth, sores in the genital or anal regions, nausea, vomiting, or diarrhea (Cleveland Clinic, 2022; Huang, et al., 2022; MeCDC, 2022). Some may have many of the symptoms, while others may have one or none, prior to developing the skin rash. Patients may also present with bacterial infections secondary to the pox, which form a rash of pimple-like, pus-filled lesions that rupture and crust over before healing. Table 1 has been created to provide a summary of recommendations for symptom management.
Table 1
Symptom Management Recommendations
Antivirals
In some instances, the infected individual may be at considerable risk for complications or already have a compromised immune system and may develop a severe form of the disease, which can include extensive lesions in the mouth or eyes, or the urethra or rectum (Conger, 2022). These individuals would be appropriate candidates for treatment using antivirals. There are some antivirals that can reduce the impact of the disease, but there is no treatment leading to a cure. “Despite the fact that monkeypox has no specific treatment, smallpox antiviral drugs such as brincidofovir, tecovirimat, and cidofovir may have effect against monkeypox because of their similar genetics” (Huang, et al., 2022, pg. 8).
Basic Prevention
The best option for treating mpox, is preventing infection with the mpox virus. As stated in previous sections, there are several ways to spread the disease and there are several ways to prevent the spread of the disease. The CDC (2022d) suggests that prevention can be achieved by avoiding close contact with someone who has the mpox rash, avoiding contact with items that an infected person has used, and thorough and frequent handwashing as a standard. Hand sanitizers containing alcohol work well, but soap and water should be used after using the bathroom.
Vaccination
A vaccinia virus-based vaccine used for other orthopoxviruses including smallpox, can be effective against mpox for those at increased risk (WHO, 2022d). These vaccines are not designed for protection against the mpox virus but have been shown to reduce the spread of the disease, as initially noted in the epidemiology reports on the 1980-1984 outbreak in what is currently known as the Democratic Republic of the Congo (Huang, et al., 2022). Jynneos is a vaccine that is given in two doses, 28 days apart, with effective protection approximately two weeks after the second dose. The vaccinia virus has been modified in this vaccine so that it cannot replicate in the cells of humans (Conger, 2022).
Another option, given as a one-time dose that provides peak protection after 28 days, ACAM2000 is a vaccine that contains a vaccinia virus that has not been altered, so the vaccinia virus can spread from the site of injection to other parts of the body or to others (Conger, 2022). It is also thought that a childhood vaccination against smallpox may offer some protection, but the vaccine originally only provided three to five years of immunity, with protection decreasing after immunity timeframe (New York State Department of Health, n.d.).
Additional options include MVA-BN, a “highly attenuated” vaccinia virus vaccine which is approved in Canada and the European union (Timm, et al., 2006) and LC16m8, also an attenuated smallpox vaccine, that is licensed for use in Japan, and is prepared as a “freeze-dried cell culture” vaccine for smallpox and mpox (Precision Vaccinations Staff, 2022, para. 1).
Conclusion
Mpox is a newer-known contagion that has shown considerable ability to spread, given the right conditions. Mpox does pose a threat to the health of humans, although currently limited to the more vulnerable populations taking part in riskier activities – for now. However, the virus can spread across the globe, as it has, moving from the 11 endemic countries in Africa to over 91 countries since spreading outside of Africa in 2003. The CDC and WHO have stepped in quickly to make plans for future risk of outbreaks, and have established surveillance, monitoring, and reporting systems to stay atop the trends with the mpox infection rates across the world.
References
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