Thread by @BlumbergSeth

Sharing some clinical and epidemiological perspective on #monkeypox gained from working with @arimoin, @jlloydsmith, and @UCSF_ID. First, if you happen to develop fever, malaise and a rash with little blisters then it’s important to know that the

chances you have monkeypox are tiny, despite these being the associated symptoms. However, you should still seek medical attention because some other virus may be the culprit (e.g. chickenpox, Zoster, HSV). Second, the mortality of monkeypox in some low-resources areas of Africa

has been around 3%, but chances are that cases in areas of greater healthcare capacity will fare better due to access to antivirals, and other medical care. Third, the smallpox vaccine is effective against monkeypox and may be useful for close contacts of cases.

However, there is no need for the general public to seek out smallpox vaccine at this time. With all that said, the epidemiology of the current outbreak is curious. Previous, carefully planned studies (doi.org/10.1093/ije/17…), have shown that the reproduction number of the

monkeypox strain circulating in the 1980s is likely less than one. That means persistence of infection requires ongoing introduction of disease from an animal reservoir. However, the current outbreak contains a significant number of cases without a known connection to an animal

reservoir and so it’s possible that the reproduction number now exceeds one (in the absence of public health intervention). This could be due to epidemiological factors such as the myriad of transmission pathways available in urban centers as compared to rural villages.

It is also possible that the DNA-encoded virus itself has evolved, but this is expected to be a much slower process than RNA-encoded viruses like SARS-CoV-2. Fortunately, three factors may help control transmission. 1) The reproduction number is not expected to be too high,

2) Ring vaccination of contacts and contacts of contacts was very effective for smallpox, and may be equally so for monkeypox (apps.who.int/iris/handle/10…) 3) The visible nature of monkeypox lesions makes it easier to rapidly identify and isolate potentially infected individuals,

provided that presymptomatic transmission is not too high (pnas.org/doi/abs/10.107…). Lastly, climate, deforestation and other habitat changes may have created favorable ecological changes for the monkeypox reservoirs (mostly rodents) thereby contributing to more animal-to-human

transmission and greater risk for subsequent spread (doi.org/10.1371/journa…). So monkeypox provides a poignant example of how #poverty, #climatechange, and #habitatchange can all interact to impact individual, national, and global health.

@IGHSatUCSF @UCSF @UCSFMedicine @UCSF_Epibiostat