Concurrent Sexually Transmitted Infections with Mpox Infections: A Brief Review

Abstract

Mpox is a viral zoonotic infection endemic to countries in Central and West Africa. The outbreak that began in May 2022 is novel for its global spread and transmission through sexual encounters. Research of this outbreak shows a high rate of concurrent sexually transmitted infections (STIs) in patients with mpox, highlighting the need to consider STIs in mpox management, and to raise awareness of historically high levels of STIs caused by inadequacies in sexual health care. It is critical to prioritize sexual health and address health disparities to control current transmission of infections and prevent future outbreaks.

Mpox is a viral zoonotic infection endemic to countries in Central and West Africa, including Benin, Cameroon, the Central African Republic, the Democratic Republic of the Congo, Gabon, Ivory Coast, Liberia, Nigeria, the Republic of the Congo, Sierra Leone, and South Sudan.¹ Mpox is an enveloped double-stranded DNA virus belonging to the Poxviridae family, chordopoxvirinae subfamily, and orthopoxvirus genus. Mpox shares the orthopoxvirus genus with smallpox virus, and immunity to mpox was previously attained with the vaccinia immunization targeted against smallpox. However, the eradication of smallpox, and the end of that routine vaccination, enabled the reemergence of mpox.² The animal reservoir for mpox includes rats, mice, prairie dogs, hedgehogs, squirrels, pigs, and primates.³ Mpox was first reported in the United States in a 2003 outbreak linked to direct contact with prairie dogs that had been housed with infected African rodents.⁴ The outbreak that began in May 2022 is novel in multiple aspects, including the scope and mode of transmission. It is the first occurrence of widespread transmission in non-endemic countries and has been reported in all 6 World Health Organization Regions (the regions of the Americas, Africa, Europe, Eastern Mediterranean, and Western Pacific), including the United States.¹ As of October 2023, there have been 31,010 cases of mpox in the United States overall,⁵ 5950 cases in California,⁶ and 250 cases in Alameda County, which corresponds to 16.4 cases per 100,000 people,⁶ higher than the national average of 13.5 cases per 100,000.⁷ Prior cases in the United States have involved exposure through foreign travel or direct contact with infected rodents. The 2022 outbreak has predominately spread through sexual encounters.⁸

Research of this outbreak shows a high rate of concurrent sexually transmitted infections (STIs) in patients, ranging from 17% to 29%,^9–14 as well as a strong history of STIs, with studies finding 41% in the last month,¹⁵ and 41% to 74% in the last year,^15,16 higher than the general STI rate of 20% of individuals in the United States in a year.¹⁷ The predominate concurrent STIs were chlamydia, gonorrhea, and syphilis. Rectal, urethral, and pharyngeal gonorrhea was reported in 3% to 19%,^9–11,15 rectal and urethral chlamydia in 5% to 12%,^9–11,15 and syphilis in 6% to 9%^9–11,15 of patients with mpox. Herpes simplex virus,^10,12 mycoplasma genitalium,^10,12 and new HIV infections^13,18 were also diagnosed. The high rates of concurrent STIs should be a reminder that patients at risk for mpox are also at risk for STIs, which are a rising concern in the United States. It is estimated that each year ~ 26 million new STIs are transmitted, costing $16 billion.¹⁷ In the United States in 2021, reported rates of all STIs increased, with rates of gonorrhea increasing 4.6%, chlamydia increasing 3.9% after previously declining, and rates of syphilis rising an alarming 32%.¹⁹ In California there were 31,357 cases of syphilis (287% more than 10 years ago), 90,890 cases of gonorrhea (169% more than 10 years ago), and 190,806 cases of chlamydia (13% more than 10 years ago).²⁰ Locally, in Alameda County, there were 220.4 cases of gonorrhea per 100,000 people,²¹ 578.2 cases of chlamydia per 100,000,²² and 17.3 cases of syphilis per 100,000,²³ all higher than the national incidences, and all increasing.

Higher rates of STIs in minorities reveal substantial health disparities. Black males have 8.5 times the rate of gonorrhea, 6.8 times the rate of chlamydia, and 4.7 times the rate of syphilis as White males.²⁴ People of color account for the highest percentage of new HIV diagnoses, with 42% in Black patients and 29% in Hispanic patients, compared to 25% in White patients,²⁴ but they are not receiving adequate preventive care. Among pre-exposure prophylaxis (PrEP) users, only 11.2% were Black and 13.1% were Hispanic, compared to White patients accounting for 68.7%.²⁵ Racial disparities are also evident in the mpox outbreak. Among the 27,946 cases of mpox in males ≥ 18 years of age between May and December 2022, 30.7% occurred in Black males, 29.5% in Hispanic males, and 27.9% in White males. However, people of color have lower rates of vaccination, with only 11.6% of Black males and 20.6% of Hispanic males receiving the smallpox/monkeypox vaccine (JYNNEOS) vaccine, compared to 51.1% of White males.²⁶ Racial and ethnic disparities in mpox result from lack of information, prevention, and vaccine access due to language, racism, homophobia, xenophobia, stigma, unemployment, and poverty.²⁶ Interventions are needed to address these disparities. The Georgia Department of Public Health conducted a vaccine pilot to administer the JYNNEOS vaccine during the Black Gay Pride festival in Atlanta, as well as at local health department clinics, large event spaces, bars, and clubs that are acceptable and convenient for Black men who have sex with men.²⁷ This program successfully increased vaccination rates of Black individuals and highlights the important role of innovative community focused strategies.

Mpox has disproportionately impacted people living with HIV (PLWH); studies have reported 24% to 54% of patients with mpox to be HIV positive.^{8–10,12,13,15–17,28} A report of 8 jurisdictions in the United States found that over the course of this outbreak there was increasing HIV prevalence among persons with mpox, suggesting mpox may be increasingly transmitted among communities of PLWH.¹⁶ PLWH with CD4 counts of < 200 cells/mm³ were found to present with severe disease, including ulcerative and necrotic lesions, protracted healing (> 4 weeks), intense pain, bacterial or fungal superinfection, and even death.²⁹ The high rate and severity of mpox in PLWH, necessitates HIV testing and evaluation for PrEP in patients with a concern for mpox, as well as utilization of HIV care systems for mpox vaccination and prevention.

People with substance use disorder are another patient population who can be at a higher risk and suffer worse outcomes, but they often distrust the health care system and should be targeted for care.³⁰The high frequency of coinfection indicates that patients presenting with a concern for mpox warrant testing for STIs, and correspondingly, patients presenting with a concern for an STI should be evaluated for chance of mpox, especially as the rash can mimic these STIs. Additionally, the high rate of mpox in PLWH, necessitates HIV testing and evaluation for PrEP in patients with a concern for mpox, as well as utilization of HIV care systems for mpox vaccination and prevention. These findings should also raise a broader awareness of STIs to improve interventions for prevention, testing, and treatment. Obtaining a thorough sexual history is necessary to achieve these goals, and the Centers for Disease Control and Prevention (CDC) recommends a “5 Ps” strategy, which discusses partners, practices, protection from STIs, past STIs, and pregnancy intention.³¹ However, this is not routinely practiced; a narrative review found less than one-third of well visits included a sexual history, but when sexual history was discussed, there was a positive association with STI testing,³² indicating substantial potential for improvement that could have considerable implications. The expansion of telehealth can be leveraged to increase accessibility, and for some patients may assuage discomfort with discussing sexual activity and requesting testing and treatment. Kaiser Permanente sexual health E-visits enable members to learn more information about sexual health, get tested for STIs, and enroll in PrEP, all of which can easily be started online (except mpox testing, which is not available through this service). Practitioners should continue to promote pathways for access and normalize an open discussion of sexual practices to be able to utilize all preventive and treatment options. Robust evidence has shown the use of doxycycline postexposure prophylaxis can significantly reduce rates of chlamydia, gonorrhea, and syphilis in men who have sex with men and transgender women,³³ and appropriate patients should be evaluated for doxycycline postexposure prophylaxis along with HIV PrEP. Mpox cases have been declining since August 2022, but there continues to be ongoing transmission and it remains a public health concern. The CDC published a Health Alert Network Health Update May 2023 to alert clinicians of 12 confirmed cases in Chicago since April 2023.³⁶ It warned of a potential resurgence in summer months and encouraged vaccination for patients at risk.³⁴ The CDC recommends a 2-dose series of the JYNNEOS vaccine as one of the most important prevention measures, but only 23% of patients at risk for mpox have been fully vaccinated.³⁵

This mpox outbreak emphasizes the potential for dissemination of new concerning pathogens with the rising interconnection of our global community. It also emphasizes the significance of sexual encounters in the spread of infection and exemplifies the effects of a syndemic, an epidemic of multiple health conditions that interact with each other in a way that increases adverse effects on communities facing inequities.³⁶ The mpox outbreak highlights the inadequacies in sexual health care that have enabled current historically high levels of STIs and allowed the spread of mpox. There is an urgent need to prioritize sexual health and it requires a syndemic approach to address interwoven diseases and social determinants of health to control current transmission of infections and prevent future outbreaks.