What is monkeypox? Should you be worried if you live in Shanghai China?

Key Points

• Research suggests mpox is a viral disease with symptoms like rash and fever, transmitted through close contact.
• It seems likely that the risk is low for Shanghai residents as of April 2025, with few cases reported and managed effectively.
• The evidence leans toward no specific travel advisories for mpox in China, but staying informed is advisable.

What is Mpox?

Mpox, previously known as monkeypox, is caused by the monkeypox virus and typically presents with a rash, fever, headache, muscle aches, back pain, low energy, and swollen lymph nodes. The rash can last 2–4 weeks. It spreads mainly through close contact with infected people, contaminated materials, or animals, and is endemic in Central and West Africa but has spread globally, including to China.

Should You Be Worried in Shanghai?

As of April 2025, the situation in Shanghai suggests a low risk. While there have been mpox cases in China, including a cluster of a new strain (clade Ib) detected in January 2025 involving five cases linked to a traveler from the Democratic Republic of the Congo, the outbreak was small and effectively managed. There are no specific travel advisories or restrictions for mpox in China, and public health authorities recommend against travel restrictions. However, it’s wise to stay updated on local health advisories, especially if you’re in high-risk groups like men who have sex with men or engage in activities increasing transmission risk.

Survey Note: Detailed Analysis of Mpox and Its Implications for Shanghai Residents

This note provides a comprehensive overview of mpox, its characteristics, transmission, and the current situation in China, particularly relevant to residents of Shanghai as of April 16, 2025. The analysis is grounded in recent reports and health data, aiming to inform and guide public health awareness.

Mpox: Definition and Symptoms

Mpox, formerly known as monkeypox, is a viral illness caused by the monkeypox virus, classified under the genus Orthopoxvirus, which also includes the variola virus responsible for smallpox. Research indicates it typically manifests with a skin rash or mucosal lesions lasting 2–4 weeks, accompanied by systemic symptoms such as fever, headache, muscle aches, back pain, low energy, and swollen lymph nodes. The disease can range from mild to severe, with severe cases more common in children, pregnant women, or those with suppressed immune systems, though it is usually self-limiting and resolves within weeks without specific treatment.

The virus has two main clades: clade I (with subclades Ia and Ib) and clade II (with subclades IIa and IIb). The global outbreak in 2022–2023 was driven by clade IIb, while recent concerns in 2024–2025 have focused on clade I, particularly subclade Ib, due to its potential for easier transmission among close contacts, including household settings.

Transmission and Global Context

Mpox is a zoonotic disease, meaning it can spread between animals and humans, with reservoirs identified in small rodents, monkeys, and other mammals in endemic regions like Central and West Africa. Human-to-human transmission occurs primarily through direct contact with infected skin or body fluids, including sexual contact, and occasionally via contaminated objects or surfaces. The 2022–2023 outbreak highlighted significant transmission among men who have sex with men (MSM), raising concerns about stigma and public health messaging, which led to the World Health Organization (WHO) adopting the term "mpox" to reduce associated discrimination.

Globally, mpox continues to be a public health concern, with ongoing outbreaks in the Democratic Republic of the Congo (DRC) and neighboring countries, prompting WHO to declare it a global public health emergency in August 2024. As of early 2025, travel-associated cases of clade I mpox have been reported in multiple countries, including China, indicating the virus’s potential for international spread.

Mpox in China: Recent Developments

In China, mpox has been classified as a Category B notifiable infectious disease since September 2023, reflecting heightened surveillance and response measures. The first imported case was reported in September 2022, with local transmission noted since June 2023, predominantly affecting the MSM population. By December 2023, there were 1,712 confirmed cases across 29 provincial-level administrative divisions, with monthly reports showing increases, such as 106 cases in June 2023 escalating to 501 by September 2023.

A significant development occurred in January 2025, when Chinese health authorities detected a cluster of the new clade Ib strain, starting with a foreigner who had traveled from the DRC. This cluster involved five cases, including four close contacts, all with mild symptoms like skin rash and blisters. The China Center for Disease Control and Prevention (China CDC) reported that these cases were managed effectively, with no additional infections found among general contacts, and patients were under treatment and monitoring. This outbreak marked China as the twelfth country outside Africa to detect clade I mpox, highlighting the virus’s global reach.

Situation in Shanghai: Risk Assessment

Specific data on mpox cases in Shanghai for 2025 was not readily available from recent reports, but given the national context, the risk appears low for residents. The January 2025 cluster was not explicitly linked to Shanghai in the reports, with investigations involving provinces like Zhejiang, Guangdong, Beijing, and Tianjin, suggesting a focus on other regions. However, China’s robust public health response, including contact tracing, case management, and enhanced entry screening for travelers, mitigates potential spread.

China has implemented measures such as monitoring arrivals for mpox symptoms since August 2024, with customs requiring declarations from individuals with travel history to affected areas or showing symptoms like fever and rash. These measures, lasting six months from August 2024, indicate ongoing vigilance. Given Shanghai’s status as a major international hub, such screening likely applies, reducing the risk of imported cases escalating locally.

Travel Advisories and Public Health Recommendations

As of April 2025, there are no specific travel restrictions related to mpox for China, with public health authorities, including the WHO and International SOS, recommending against such measures. Enhanced entry screening, including health declarations and temperature checks, is in place at borders, but these are not prohibitive. For Shanghai residents, this suggests minimal disruption to daily life, but awareness is crucial, especially for those traveling to or from regions with ongoing outbreaks, such as Central Africa.

The U.S. Centers for Disease Control and Prevention (CDC) updated its travel health advisory in April 2025, noting ongoing person-to-person transmission of clade I mpox in countries like DRC and Kenya, but this does not directly impact domestic risk in China. Local health advisories from the Shanghai Center for Disease Control and Prevention (SCDC) should be monitored for any updates, particularly for high-risk groups, such as those engaging in close contact activities or with recent travel history to affected areas.

Risk Factors and Precautions

The evidence leans toward mpox posing a higher risk to specific populations, such as MSM, due to sexual transmission patterns observed globally and in China. For the general population in Shanghai, the risk is low, given the small number of cases and effective management. However, precautions include avoiding close contact with symptomatic individuals, practicing good hygiene, and getting vaccinated if eligible, as vaccines like JYNNEOS are recommended for at-risk groups, though availability in China may vary.

Residents should stay informed through official channels, such as the SCDC website (Shanghai CDC), for any localized updates. Symptoms like fever, rash, or swollen lymph nodes warrant medical consultation, and declaring travel history to health authorities upon entry is advised if relevant.

Conclusion

In conclusion, mpox is a manageable viral disease with clear symptoms and transmission routes, and while it has affected China, the situation as of April 2025 suggests a low risk for Shanghai residents. The effective handling of recent cases, lack of travel restrictions, and ongoing public health measures support this assessment. However, staying informed and taking precautions, especially for high-risk groups, remains essential for personal and community health safety.