Mpox in Cities and the Countryside, United States, 2022

From May 10 to December 31, 2022, 29,980 confirmed and probable cases of monkeypox (mpox) were reported to CDC, mostly among cisgender adult men who reported recent sexual partners of the same gender. Urban–rural differences in health, and in diagnoses of HIV and other sexually transmitted infections, are well documented, so CDC looked at how mpox incidence among people aged 15–64 differed by how urban their county was, and by gender and by race and ethnicity.

How the analysis worked

Health departments reported cases through national case surveillance. Counties were classed with the 2013 National Center for Health Statistics scheme: four urban levels (large central, large fringe, medium, small) and, combined here because of small numbers, rural (micropolitan and noncore). Cases in each level were divided by that level's 2021 population aged 15–64; the analysis was limited to that age range because most cases fell in it and to limit bias from differing age profiles.

Of the 29,980 cases, 29,311 (97.8%) were in people aged 15–64 in the 50 states and the District of Columbia.

Where cases were

• 71.0% of cases were in large central urban areas, but every level had cases, including 440 (1.5%) in rural areas.
• The median patient age was 34 years, and ages were similar across levels.
• Cisgender men were 95.7% of cases in large central urban areas and 94.7% in rural areas; cisgender women, 2.3% and 4.6%.
• Hispanic patients were 33.8% of cases in large central and 26.5% in large fringe urban areas, but 14.3% in small urban and 15.1% in rural areas. White patients were a larger share in small urban (42.8%) and rural (43.3%) areas than elsewhere. Black patients ranged from 30.8% of cases in large central to 40.1% in large fringe urban areas.

Incidence

Overall incidence was 13.5 per 100,000 people aged 15–64. In every kind of area it peaked in August and declined from October to December.

Mpox incidence among people aged 15–64 by gender, by race and ethnicity, and by urban–rural level, May 10–December 31, 2022. CDC.

• Gender. Incidence was 27.2 among cisgender men and 0.7 among cisgender women. For cisgender men, the rural rate (2.8) was approximately 4% of the large central urban rate (65.0); for cisgender women, the rural rate (0.1) was approximately 11% of the large central rate (1.3). The gap between men and women was widest in large central urban areas (risk ratio 51.2) and narrower in rural areas (19.8).
• Race and ethnicity. In urban and rural areas alike, incidence was higher among Black than White people, and higher among Hispanic than White people; it was also higher among Black than Hispanic people. The absolute gap was largest in large central urban areas, 52.3 per 100,000 among Black people against 19.7 among White people. The relative gap was largest in rural areas, with a Black–White risk ratio of 7.2: rural rates were 6.2 among Black, 2.4 among Hispanic and 0.9 among White people.

What it means

About 85% of Americans live in urban areas, and the outbreak was driven mainly by transmission among cisgender men with recent same-gender partners in large central urban areas. Vaccination campaigns and other prevention were concentrated in urban areas. An estimated 37% of people at risk in the United States received one dose of vaccine and 23% two, with wide regional variation.

But cases also occurred among cisgender men outside big cities and among cisgender women everywhere. Lower incidence in less urban areas may mean less immunity from infection there, leaving larger shares of those populations susceptible. Rural barriers — fewer service sites, provider shortages, cultural barriers, stigma and fewer referrals for testing and vaccination — on top of long-standing racial and ethnic health disparities may help explain the higher rural rates among Black and Hispanic people.

The authors call for continuing national surveillance in every kind of area so everyone at risk is tested and treated, for equity-focused vaccination of gay, bisexual and other men who have sex with men in cities, and for prevention that includes everyone at risk. CDC recommends a full 2-dose course of JYNNEOS vaccine for men who have sex with men and others at risk of exposure.

Limits

• There were too few cases to estimate incidence by urbanicity for transgender and gender-diverse people or for some racial and ethnic groups.
• Gender data are not collected the same way everywhere; where self-reported gender was missing, sex was used and people were presumed cisgender, which may undercount transgender and gender-diverse people.
• Mpox may have been less likely to be diagnosed in rural and less urban areas, for lack of access or testing, so incidence there may be underestimated.

Sources

Based on Zelaya CE, Smith BP, Riser AP, et al., "Urban and Rural Mpox Incidence Among Persons Aged 15–64 Years — United States, May 10–December 31, 2022," MMWR Vol. 72, No. 21, CDC; a work of the United States government in the public domain. A footnote gives the number of cases used for White patients' incidence as 8,500, while the table counts 8,050; neither is given here. The discussion calls rural rates among Black people "approximately six" times those among White people, against a reported risk ratio of 7.2; the page gives the rates and the risk ratio. The report's social-media graphic is not reproduced.