How many mpox clade Ib cases will be reported in the United States in 2026?
$0.00
1
7
How many mpox clade Ib cases will be reported in the United States in 2026?
$0.00
1
7
AI Analysis
Trader mode: Actionable analysis for identifying opportunities and edge
About This Event
2026 If the total number of mpox clade Ib cases reported in the United States during 2026 is above X then the market resolves to Yes. Cases are determined at 10:00 AM ET on the Expiration Date, January 8. Cases that actually occur between the end of the specified time period and Expiration do not count, but newly reported cases during this window do count if they are backdated to 2026. See the full rules for how Source Agencies are prioritized. This market refers exclusively to human cases. Thi
What Prediction Markets Are Forecasting
Traders on Kalshi currently give an 80% chance that the United States will report more than 10 cases of mpox clade Ib during 2026. That's roughly a 4 in 5 chance, which is a strong but not overwhelming signal. Think of it this way: if you ran this scenario 100 times, the market expects 2026 to cross that 10-case threshold in about 80 of them.
The market isn't forecasting a massive outbreak. Ten cases is a low bar, and the real question is whether the virus will continue its slow, sporadic introduction into the country through travel or local transmission chains. The odds suggest traders expect at least a handful of cases to appear, but they're not pricing in anything resembling a large epidemic.
Why the Market Sees It This Way
Three factors are likely driving this prediction.
First, clade Ib mpox has been spreading in Central and East Africa since late 2023, particularly in the Democratic Republic of Congo, Burundi, and Uganda. The World Health Organization declared it a public health emergency of international concern in August 2024. International travel means occasional introductions into the US are almost inevitable.
Second, we've already seen what happened in 2024 and 2025. The US reported its first clade Ib case in November 2024, linked to travel from East Africa. Since then, a handful of additional cases have appeared, mostly among travelers or their close contacts. The pattern isn't explosive, but it's persistent.
Third, there's a seasonal and behavioral dimension. Mpox spreads through close contact, including sexual contact. Outbreaks have clustered in specific social networks. The market seems to believe that with continued global circulation, 2026 will see enough introductions and secondary transmissions to exceed 10 cases. That's a modest bet, not a dramatic one.
Key Dates and Events to Watch
The market resolves on January 8, 2027, covering all cases reported in 2026. Watch for a few things throughout the year.
Travel seasons matter. Cases often spike after summer travel and major events. Any new outbreak in Africa that expands the geographic reach of the virus would raise the odds of more US cases. Also watch for CDC surveillance updates; they publish weekly mpox data, and any shift in testing guidance could change how many cases get counted.
The expiration date includes a quirk worth noting: cases that occurred in 2026 but were only reported in early January 2027 still count. That backdating rule means the final weeks of the year carry some uncertainty.
How Reliable Are These Predictions?
Prediction markets have a decent track record with disease forecasting, but this is a hard case. Small numbers make probabilities noisy. The difference between 8 cases and 12 cases is just a few unlucky or lucky transmission events, and that's within the margin of error for any forecasting method.
The market is also pricing in a lot of assumptions about global health conditions that could change quickly. A vaccine campaign in Africa that suppresses the virus would lower the odds. A new variant that spreads more easily would raise them. Markets can't predict scientific surprises.
Still, for a question this specific and this small, the market's 80% estimate is a reasonable baseline. It's saying: expect a few cases, don't expect a crisis, but don't be shocked if the number stays in the single digits either.
Current Market Outlook
Kalshi traders currently price an 80% chance that the United States will report more than 10 mpox clade Ib cases during 2026. That is a strong conviction. An 80% probability implies the market sees double-digit domestic cases as the baseline scenario, not a tail risk. The contract resolves on January 8, 2027, with cases backdated to 2026 counted if reported in the first week of January.
Key Factors Driving the Odds
The market is betting on continued spread of a virus that has already demonstrated its ability to cross borders. Clade Ib emerged in the Democratic Republic of Congo in late 2023 and triggered a WHO global health emergency declaration in August 2024. By late 2025, confirmed cases had appeared in at least 20 countries across Africa and Europe, including Sweden, Thailand, and Germany. The United States recorded its first clade Ib case in November 2024, a traveler from eastern Africa.
The mechanism matters. Clade Ib transmits efficiently through close contact, including sexual networks, and has shown secondary attack rates among household contacts that exceed the 2022 clade II outbreak. That 2022 outbreak produced over 32,000 US cases. The infrastructure for detection is also better now. Wastewater surveillance, clinician awareness, and CDC testing protocols that specifically distinguish clade Ib mean case finding will be more aggressive than in 2022.
Travel volume is the third factor. The US sees hundreds of thousands of arrivals from African nations monthly. With sustained community transmission in DRC, Burundi, and Uganda, importation events are probabilistic, not speculative.
What Could Change These Odds
The obvious bear case is containment. If the DRC outbreak peaks in early 2026 and vaccination campaigns in affected regions gain traction, importation pressure drops. The WHO's emergency declaration triggered a coordinated response, but vaccine supply for clade Ib specifically remains limited. A second bear scenario is underreporting. If US cases cluster in populations with poor healthcare access, the official count could lag true incidence, but that would push the market toward Yes, not No.
The bull case for Yes is seasonality. Mpox transmission historically peaks in late summer and fall. A single superspreader event at a large gathering could generate dozens of cases in weeks. The 2022 outbreak went from zero to over 700 cases per week in under two months.
Cross-Platform Analysis
Kalshi is the only platform trading this specific contract. Polymarket has a broader mpox case count market for global totals, but nothing US-specific with a 10-case threshold. The absence of a second market means no arbitrage signal. The 80% price reflects genuine conviction from a thin but informed trading pool, likely including public health professionals who track this data weekly. For context, Kalshi's own market on clade Ib cases in 2025 traded near 60% for the same 10-case threshold, and actual 2025 counts came in well above that level. The market is extrapolating that trajectory forward.
AI-generated analysis based on market data. Not financial advice.
Overview
Mpox, formerly known as monkeypox, is a viral zoonotic disease caused by the monkeypox virus, a member of the Orthopoxvirus genus. The virus has two distinct clades: clade I (formerly the Congo Basin clade) and clade II (formerly the West African clade). Clade Ib is a newly identified subclade of clade I that emerged in the Democratic Republic of the Congo (DRC) in late 2023, and it has since spread to multiple countries, raising global health concerns. In August 2024, the World Health Organization (WHO) declared the clade Ib outbreak a Public Health Emergency of International Concern (PHEIC) due to its rapid spread and higher mortality rate compared to clade II. The United States reported its first case of clade Ib mpox in November 2024, and the number of cases in 2026 will depend on multiple factors including international travel, public health interventions, and the effectiveness of vaccination campaigns. This prediction market focuses on the total number of clade Ib cases reported in the United States during 2026, which is a key indicator of the outbreak's trajectory and the adequacy of containment measures. The interest in this topic stems from the potential for wider community transmission, the severity of the disease, and the lessons learned from the 2022 multi-country clade II outbreak that affected over 30,000 people in the U.S. alone. Understanding the case count for 2026 is not just about numbers, but about the effectiveness of surveillance, the impact of public health policies, and the preparedness of the healthcare system to handle a potentially severe infectious disease.
Historical Context
The mpox virus was first identified in 1958 in laboratory monkeys, with the first human case reported in 1970 in the DRC. For decades, the disease was largely confined to Central and West Africa, with sporadic outbreaks. In 2003, the U.S. experienced its first mpox outbreak, linked to imported rodents from Ghana, which resulted in 47 confirmed cases. However, it was not until 2022 that mpox became a global concern, when a clade II outbreak spread to over 100 countries, primarily affecting men who have sex with men. The U.S. recorded over 30,000 cases during that outbreak, which was controlled through vaccination and behavioral changes. The emergence of clade Ib in late 2023 marked a new chapter, as this subclade appeared to have a higher mortality rate and was spreading through sexual contact, including in new demographics such as children and sex workers. In August 2024, the WHO declared the outbreak a PHEIC, and the first U.S. case of clade Ib was reported in November 2024 in a traveler who had recently returned from East Africa. Since then, sporadic cases have been reported, but no sustained community transmission has been documented in the U.S. The historical context shows that the U.S. has the tools to control mpox, but the success in 2026 will depend on maintaining surveillance and vaccination efforts, as well as preventing imported cases from becoming established.
Why It Matters
The number of mpox clade Ib cases in the U.S. in 2026 is a critical metric for assessing the effectiveness of public health measures and the potential for a larger outbreak. If cases remain low, it indicates that the current surveillance and vaccination strategies are working, and the risk to the general public is minimal. However, if cases rise significantly, it could signal community transmission, which would require a more aggressive response, including targeted vaccination campaigns and public health messaging. The economic implications are also significant; a larger outbreak would strain healthcare resources, lead to lost productivity, and potentially require additional federal funding. Moreover, the U.S. response serves as a model for other countries, and its success or failure will influence global confidence in containing mpox. Finally, the number of cases will impact the livelihoods of individuals in high-risk groups, particularly men who have sex with men and sex workers, who may face stigma and discrimination. The prediction market itself reflects the uncertainty among experts about the trajectory of the outbreak, and the outcome will provide valuable data for future forecasting.
Current Status
As of January 2025, the U.S. has reported only a handful of clade Ib cases, all of which were travel-associated. The CDC has not detected any community transmission, and the risk of widespread transmission is currently considered low. However, the global situation remains dynamic, with ongoing outbreaks in the DRC and neighboring countries, and new cases have been reported in other countries, including the United Kingdom and Sweden. The CDC has updated its travel health notices and continues to recommend that travelers to affected areas take precautions. The Biden administration has not announced any major new mpox initiatives, but the Department of Health and Human Services has stated that it is monitoring the situation closely. The outcome of the 2026 case count will depend on whether the U.S. can maintain its surveillance and response capabilities, and whether the virus mutates to become more transmissible.
Frequently Asked Questions
What is mpox clade Ib?
Mpox clade Ib is a subclade of the clade I monkeypox virus, which is endemic to Central and West Africa. It emerged in 2023 in the DRC and has a higher mortality rate than clade II, and it can spread through sexual contact.
How many mpox cases are in the US in 2026?
The exact number is not yet known, but as of early 2025, only a few cases have been reported. The number for 2026 will depend on the effectiveness of public health measures and the global trajectory of the outbreak.
Is there a vaccine for mpox?
Yes, the JYNNEOS vaccine is approved for mpox prevention in the U.S. It is recommended for people at high risk, such as those with multiple sexual partners or who have been in close contact with an infected person.
What are the symptoms of mpox?
Symptoms include fever, headache, muscle aches, and a rash that can appear on the face, hands, feet, and genitals. The rash can be painful and may last for several weeks.
Educational content is AI-generated and sourced from Wikipedia. It should not be considered financial advice.
