According to the UKHSA (UK Health Protection Agency), as of 22 August, there are 3,207 confirmed and 133 highly probable cases of monkeypox in the UK, or 3,340 in total. Of these, 3,191 are in England.
Many of the symptoms of the disease initially appear similar to those of chickenpox, but there are several important differences between the two.
First, diseases are caused by different viruses: monkeypox is an orthopoxvirus, while chickenpox is caused by the varicella-zoster virus, which causes shingles.
Both viruses can be spread by close contact through respiratory droplets and by direct contact with skin sores and recently contaminated objects.
While chickenpox is a common and highly contagious disease, monkeypox is rare and spreads less easily.
Monkeypox is usually a mild illness with early symptoms such as fever, headache, muscle aches, back pain, chills and tiredness.
Although many of these symptoms also appear in people infected with chickenpox, swollen lymph nodes are a hallmark of monkeypox, which is not present in chickenpox.
According to the US Centers for Disease Control and Prevention, the incubation period for monkeypox can be anywhere from seven to 14 days, while chickenpox can take up to 16 days for symptoms to appear.
After a monkeypox infection, initially a chickenpox-like rash usually appears one to three days after a fever.
The rash goes through several different stages, first developing into fluid-filled papules and pustules before crusting and falling off.
However, smallpox rash forms differently.
The spots in a chickenpox rash do not develop evenly, as they appear at different times. However, monkeypox lesions appear and develop at the same time.
Symptoms of monkeypox usually last for two to four weeks. According to the WHO (World Health Organisation), some strains can cause severe disease, with a recent mortality rate ranging between 3 and 6 percent.
Symptoms of chickenpox can last up to two weeks, but usually go away within seven days.
The UK government has published new guidance advising people who have had the virus and who have come in direct contact with a person infected with monkeypox to self-isolate for three weeks.
People in this group are also asked not to travel and are advised to avoid contact with immunocompromised people, pregnant women and children below 12 years of age.