How dangerous is monkeypox? UCSF Seth Blumberg explains

Monkeypox, which is commonly encountered in Central and West Africa, has spread to more than 12 countries, including the United States. There are currently hundreds of cases of outbreaks. This fuels the risk of even more infections, but it’s not surprising that the still quite active COVID pandemic has triggered it.

Monkeypox can be fatal at times, especially in poor medical care, and is closely associated with smallpox, which has plagued humans for thousands of years. Smallpox has been eradicated for a global vaccination campaign. In the United States, high-dose vaccination ended in 1972, but vaccines remain in stock. Monkeypox has been known since the late 1950s, and despite its name, its natural reservoir is a rodent. Most often, it spreads among humans through contact with diseased lesions or through respiratory droplets exhaled during prolonged intimate contact.

It is believed that air travel from Africa triggered the outbreak. Contact tracing is in progress. The Centers for Disease Control and Prevention (CDC) hosted a press conference this week, and authorities are heavily focused on spreading the virus between men who have sex with men who appear to explain most cases of current outbreaks. I matched.

We talked Seth Blumberg, MD, PhD, Associate Professor of Medicine at the University of California, San Francisco, a clinical expert in infectious diseases, and a computational scientist studying the emergence and elimination of population-level illnesses. Monkeypox is one of the illnesses he studied.

What are the similarities and differences between monkeypox and smallpox?

Monkeypox and smallpox are the same class of virus. They share mutual immunity. That is, protection for one brings protection for the other. In particular, vaccinations developed to protect against smallpox protect against monkeypox. There are overlaps in clinical symptoms. Both are associated with fever, swelling of the lymph glands, malaise, and blistering rash (a rash with few blisters), which can be distributed anywhere on the body and are easily confused with chickenpox. Fortunately, the biggest difference is that monkeypox looks much worse than smallpox and is not fatal. In particular, the West African strains of monkeypox that are currently circulating are less pathogenic than the strains found in Central Africa.

Is monkeypox more and more popular?

In recent years, the number of cases of monkeypox has increased in Africa. This increase is due to a combination of factors that affect both animal-to-human and human-to-human transmission. One of the key factors is the loss of some immunity within the population because they have not been vaccinated against smallpox.

Regular vaccination against smallpox in the United States ended in 1972. How well are vaccinated and unvaccinated people protected from monkeypox?

It is not as protected as it was 50 years ago when smallpox vaccination was common. Monkeypox does not show much of the disease burden to measure defense, so it is not really known how much artificial immunity remains. Hopefully, the elderly in the population are protected from prior vaccinations, and there is a good chance that this will happen. I don’t know for sure.

Why is the COVID vaccine developed just a year ago already in need of renewal, while the vaccine developed more than half a century ago to combat smallpox is still effective against monkeypox today?

Viruses have the amazing ability to change over time by being genetically mutated. However, the rate of change varies from virus to virus. The monkeypox virus gene is encoded by DNA, while the SARS-CoV-2 gene is encoded by RNA. RNA viruses, including the SARS-CoV-2 virus that causes COVID 19, tend to mutate much faster than DNA viruses such as monkeypox. For this reason, it is generally difficult to devise a long-term effective vaccine against RNA viruses compared to DNA viruses.

What have you learned from past studies of the development of monkeypox and other human and animal diseases?

I think one of the things monkey pox shows is the interaction between personal health, people’s habits and behaviors, national health, world health, politics, economy, poverty, wildlife and climate change. As aspects of the world change, it affects the emergence of epidemiology and disease.

Most doctors have never seen monkeypox. Is it difficult to diagnose?

Monkeypox is one of several diseases that manifest as bullous rash. Trained doctors can often identify which illness is most likely. For example, herpes simplex virus rashes are usually confined to the genital or oral area. Shingles, caused by the reactivation of the virus that causes chickenpox, usually wraps part of the trunk in a narrow band, causing a unique follicular rash that affects only one side of the body. However, it can be difficult to distinguish between monkeypox and chickenpox. Both cause a widespread rash. Chickenpox is much more likely, but such a rash deserves medical evaluation.

Is there any suspicion that the monkeypox virus is spreading differently than it was in the past?

It may have evolved in a way that is easier to communicate. In the current outbreak, the virus is genetically sequenced and may not show significant changes, but it may take some time to understand the importance of subtle changes. Indeed, we have never seen so many cases outside Africa. Perhaps there is an easier route to infect cities and during large-scale events where the virus has never been seen before. Although it may not be the cause of this outbreak, changes in the environment, such as whether another animal population has become a new reservoir of virus, should also be considered.

Can this monkeypox outbreak pose a major global health threat like COVID?

I think it’s much more likely to control monkeypox than COVID. For one thing, monkeypox is not contagious unless biology changes dramatically, and it seems unlikely. Second, monkeypox infections develop within an individual and take much longer to spread. Therefore, there are more opportunities to protect your contacts. Third, monkeypox may be less contagious before a visible rash highlights the need for quarantine, while COVID is contagious before symptoms appear and even asymptomatic. There is likely to be.

Many cases of current outbreaks have been between men who have sex with men, who are the focus of the CDC. Do you think these men are at greater risk?

The case reports we are hearing (infection events between sexual partners) may simply be due to prolonged proximity or skin, as we do not yet have complete data on the mode of infection at the current outbreak. It is important to recognize that. Contact with the skin. I have never seen any data showing that the virus is transmitted by semen or vaginal fluid. The virus does not target people specifically for sexual activity. When one has a rash, I am worried about the close contact between the two.

How much do you need to worry about monkeypox now?

Based on the past history of monkeypox over the past few decades, and from what we have seen so far in the current number of cases, monkeypox has not reached the level of threat comparable to the ongoing COVID pandemic. Therefore, I think we can be cautiously optimistic that the outbreak will be suppressed, but I think it is important to have some awareness of monkeypox and be prepared for unexpected situations. We need to support public health agencies and laboratories working hard to understand epidemiology, pathophysiology and treatment options so that every situation can be addressed with the scientific accuracy possible. I have.