Tag: infectious disease

Mpox: Everything you need to know about the 2024 outbreak

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Illustration of the mpox virus

Getty Images/Science Photo Library

The World Health Organization (WHO) has declared a public health emergency of international concern over an ongoing outbreak of mpox – formerly known as monkeypox – in Central and West Africa. This is the second time in two years that the disease has spread enough to prompt such a declaration from the WHO. On 15 August, Swedish health officials confirmed a case as the first known infection outside of Africa with the mpox strain that is currently driving the outbreak.

What is mpox?

Mpox is an infectious disease caused by a virus that belongs to the same family as that which causes smallpox. It regularly spreads among animals in Central and West Africa such as rodents and monkeys, but occasionally jumps to people, causing small outbreaks.

There are two distinct lineages of mpox: clade I and clade II. Clade I is associated with more severe disease and higher risk of death. A subtype of clade I, called clade Ib, is driving the current outbreak, while the global mpox outbreak in 2022 and 2023 was spurred by a subtype of clade II.

So far, there is no evidence to suggest that clade Ib is more dangerous than the original clade I strain, said Jonas Albarnaz at The Pirbright Institute in the UK in a statement.

How many cases of mpox have there been in 2024?

The Africa Centres for Disease Control and Prevention reported on 13 August that there have been more than 17,000 suspected cases across the continent. “This is just the tip of the iceberg when we consider the many weaknesses in surveillance, laboratory testing and contact tracing,” the agency said in the statement.

There have been 15,664 reported cases and 537 deaths so far in the Democratic Republic of the Congo alone, according to the WHO. This exceeds the total seen in 2023, according to a statement by Tedros Adhanom Ghebreyesus at the WHO on 15 August.

Where has mpox been detected?

The current outbreak originated in a small mining town in the Democratic Republic of the Congo (DRC). The mpox variant has now spread to at least 11 other African countries, including four that had previously never reported mpox: Kenya, Rwanda, Burundi and Uganda. Mpox has also been detected in one person in Sweden.

What is the survival rate for mpox?

While more than 99.9 per cent of people who fall ill with clade II survive, mpox outbreaks of clade I have killed up to 10 per cent of people who become sick. Children and people who are immunocompromised or pregnant are especially vulnerable to severe disease.

What are the symptoms of mpox?

The first mpox symptom is usually a rash, which begins as a flat sore and then develops into a blister that may be itchy or painful. The rash tends to start on the face before spreading across the body and extending to hands and feet. People can also get lesions in their mouth or on the genitals or anus.

The rash and lesions usually last between two and four weeks and are often accompanied by other symptoms such as fever, headache, muscle aches, back pain, fatigue and swollen lymph nodes. Symptoms usually begin within a week of contracting the virus but can start anywhere from one to 21 days after exposure. However, some people can contract the virus without experiencing symptoms.

How does mpox spread?

Mpox is spread through close contact with people who have the illness. Usually this is through skin-to-skin contact, such as sex, kissing or touching. The virus can also spread through respiratory droplets and contact with contaminated materials such as bedsheets, other linens or sharp objects like needles. People remain infectious until all of their sores heal.

Mpox can also spread through contact with infected animals such as through bites or scratches, or when people hunt or eat them.

Young adults and children have been most affected by the current outbreak, a trend that was not seen in the 2022-2023 outbreak. In some provinces of the DRC, children under 15 account for up to 69 per cent of suspected cases.

How is mpox treated?

Treatment primarily consists of managing symptoms and preventing complications like secondary infections. Some antivirals that were originally developed for treating smallpox have also been used to treat mpox in the past. However, results from a recent trial of the antiviral drug tecovirimat, which was used in the previous outbreak, found that it was not effective against the clade I virus. People who have mpox should self-isolate and wear a mask. They should also avoid scratching sores, which can prevent them from healing, increase the risk of secondary infections and cause them to spread to other parts of the body.

Is there an mpox vaccine?

There is an mpox vaccine, which provides the best protection after two doses. Smallpox vaccines have also been found to protect against mpox, though it isn’t clear if any of these vaccines will be effective against the new mpox variant.

People are recommended to get vaccinated only if they are at high risk of contracting mpox. For people who aren’t in areas affected by the current outbreak, the risk remains very low.

Countries in Africa currently have minimal to no vaccine supplies, though estimates suggest the region needs 10 million doses, said Jimmy Whitworth at the London School of Hygiene & Tropical Medicine in a statement.

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August 16, 2024
How to Avoid Getting Sick This Summer

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This article is republished from The Conversation under a Creative Commons license.

As flowers bloom and temperatures climb, many are eager to get back outside. But while the sun may be shining, there is a dark side that can make the great outdoors not so great.

Gangs of germs are lurking in the woods, in the soil, in the water, and in your food, ready to rain on your summer parade.

I’m a professor of microbiology at the Indiana University School of Medicine, where I study and teach about infectious disease. Here are some things to keep in mind to help you and your loved ones stay free of illness while enjoying summer activities.

Germs in the Backyard

There’s nothing like the smell of a good barbecue and fresh goodies from your own garden. To make sure people leave your party with only good memories, be aware of germs commonly linked to food poisoning, which can result in diarrhea, cramps, nausea, vomiting, and fever.

Meats, including fish and poultry, often house harmful bacteria such as Salmonella, E. coli, or Listeria. Raw meat can contaminate anything it touches, so be sure to wash your hands and disinfect surfaces and utensils. To avoid cross contamination, do not keep uncooked meat near prepared foods. Meat products must be cooked to proper temperatures to ensure harmful germs are destroyed before consuming.

Washing cooking utensils that touch raw meat can reduce cross contamination.

Photograph: Catherine Falls Commercial/Moment via Getty Images

In addition to bacteria, a parasite called Toxoplasma gondii can cause acute food poisoning. Toxoplasma parasites are shed as microscopic oocysts in the feces of infected cats. Oocysts persist in the environment for a year or more, and other animals, including people, can inadvertently ingest them.

Upon infection, Toxoplasma forms tissue cysts in the flesh of food animals—another reason to cook your meats thoroughly. Pregnant people need to take special care in avoiding Toxoplasma, since the parasite can cross the placenta and cause miscarriage or birth defects.

To avoid getting toxoplasmosis from oocysts, people should wear gloves while gardening, wash fruits and vegetables, and make sure the sandbox is free of cat poop and covered when not in use.

Germs in the Water

Recreational water facilities such as pools, water parks, and fountains are a great way to beat the summer heat. The smell of chlorine is a good sign that the water is being treated to kill many types of germs.

Unfortunately, some germs can remain infectious in chlorine for several minutes or days, which is plenty of time to spread from one person to another. These include viruses such as norovirus, bacteria such as E. coli, and parasites such as Cryptosporidium and Giardia.

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June 15, 2024
Why we still don't know exactly how bird flu is spreading between cows

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Early evidence suggests that a bird flu virus called H5N1 may be infecting dairy cows through contaminated milking equipment – but poor surveillance has made it nearly impossible to rule out other possibilities

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May 21, 2024
The Complex Social Lives of Viruses

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The original version of this story appeared in Quanta Magazine.

Ever since viruses came to light in the late 1800s, scientists have set them apart from the rest of life. Viruses were far smaller than cells, and inside their protein shells they carried little more than genes. They could not grow, copy their own genes, or do much of anything. Researchers assumed that each virus was a solitary particle drifting alone through the world, able to replicate only if it happened to bump into the right cell that could take it in.

This simplicity was what attracted many scientists to viruses in the first place, said Marco Vignuzzi, a virologist at the Singapore Agency for Science, Research and Technology Infectious Diseases Labs. “We were trying to be reductionist.”

That reductionism paid off. Studies on viruses were crucial to the birth of modern biology. Lacking the complexity of cells, they revealed fundamental rules about how genes work. But viral reductionism came at a cost, Vignuzzi said: By assuming viruses are simple, you blind yourself to the possibility that they might be complicated in ways you don’t know about yet.

For example, if you think of viruses as isolated packages of genes, it would be absurd to imagine them having a social life. But Vignuzzi and a new school of like-minded virologists don’t think it’s absurd at all. In recent decades, they have discovered some strange features of viruses that don’t make sense if viruses are lonely particles. They instead are uncovering a marvelously complex social world of viruses. These sociovirologists, as the researchers sometimes call themselves, believe that viruses make sense only as members of a community.

Granted, the social lives of viruses aren’t quite like those of other species. Viruses don’t post selfies to social media, volunteer at food banks, or commit identity theft like humans do. They don’t fight with allies to dominate a troop like baboons; they don’t collect nectar to feed their queen like honeybees; they don’t even congeal into slimy mats for their common defense like some bacteria do. Nevertheless, sociovirologists believe that viruses do cheat, cooperate, and interact in other ways with their fellow viruses.

The field of sociovirology is still young and small. The first conference dedicated to the social life of viruses took place in 2022, and the second will take place this June. A grand total of 50 people will be in attendance. Still, sociovirologists argue that the implications of their new field could be profound. Diseases like influenza don’t make sense if we think of viruses in isolation from one another. And if we can decipher the social life of viruses, we might be able to exploit it to fight back against the diseases some of them create.

Under Our Noses

Some of the most important evidence for the social life of viruses has been sitting in plain view for nearly a century. After the discovery of the influenza virus in the early 1930s, scientists figured out how to grow stocks of the virus by injecting it into a chicken egg and letting it multiply inside. The researchers could then use the new viruses to infect lab animals for research or inject them into new eggs to keep growing new viruses.

In the late 1940s, the Danish virologist Preben von Magnus was growing viruses when he noticed something odd. Many of the viruses produced in one egg could not replicate when he injected them into another. By the third cycle of transmission, only one in 10,000 viruses could still replicate. But in the cycles that followed, the defective viruses became rarer and the replicating ones bounced back. Von Magnus suspected that the viruses that couldn’t replicate had not finished developing, and so he called them “incomplete.”

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May 19, 2024
Bird flu has hit US cows but tracking efforts fall woefully short

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Bird flu is now in US dairy herds

mladenbalinovac/Getty Images

Public health experts warn not enough is being done to contain the spread of a bird flu virus in US dairy cows, raising the risk of the disease spilling over into people.

More than a month has passed since the US Department of Agriculture (USDA) first announced that dairy cattle in several US states had tested positive for a bird flu virus called H5N1, which has killed millions of birds and hundreds of mammals worldwide. The virus has since been detected in 36…

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May 7, 2024
Lack of US bird flu tracking in cows may raise risk of human infection

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Bird flu is now in US dairy herds

mladenbalinovac/Getty Images

Public health experts warn not enough is being done to contain the spread of a bird flu virus in US dairy cows, raising the risk of the disease spilling over into people.

More than a month has passed since the US Department of Agriculture (USDA) first announced that dairy cattle in several US states had tested positive for a bird flu virus called H5N1, which has killed millions of birds and hundreds of mammals worldwide. The virus has since been detected in 36…

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May 7, 2024
No One Knows How Far Bird Flu Has Spread

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In late March, the US Department of Agriculture (USDA) announced it had detected cases of bird flu in dairy cattle. Initially discovered in dairy farms in Texas, Kansas, and New Mexico, there are now 36 confirmed outbreaks in dairy herds in nine states.

Although the H5N1 virus circulates widely in wild birds, it is now circulating among dairy cattle in the US. The USDA has confirmed transmission between cows in the same herd, from cows to birds, and between different dairy cattle herds.

But the reported outbreaks are likely to be a major underestimation of the true spread of the virus, says James Wood, head of veterinary medicine at the University of Cambridge. “It’s likely there is going to be a fair amount of underreporting and underdiagnosis,” he says.

Tests by the Food and Drug Administration (FDA) of retail milk samples might give some indication of how widespread the virus is. The agency found viral fragments in one in five samples of commercial milk, although this virus had been deactivated by pasteurization so was not infectious.

So far there is only one confirmed human infection in the outbreak: someone in Texas who had close contact with dairy cattle. Their only reported symptom was conjunctivitis, and the individual was told to isolate themselves and take an antiviral drug for flu. But anecdotal reports of illness on dairy farms hints that infections among humans may be more widespread than official data suggests. Although human infections have tended to be rare, the virus is dangerous—just over half of the human cases recorded by the World Health Organization over the past two decades have been fatal.

Dairy workers are most at risk of possible infection in the current outbreak, but understanding the extent of any infections is extremely tricky, says James Lawler, professor of infectious diseases at University of Nebraska Medical Center. More than half of workers in the US dairy industry are immigrants, and many of them are undocumented.

These undocumented workers are unlikely to want to put themselves at risk by coming for testing, Lawler says. “There’s an inherent disincentive that many of the workers, because of their status as undocumented immigrants, are not raising their hands.” The result, Lawler says, is that it’s difficult for scientists to track any possible spread of the virus through humans.

Another issue is incentivizing owners of dairy farms to report when their animals seem sick. The USDA Animal and Plant Health Inspection Service specifically provides payments for poultry farmers who have to kill their livestock due to bird flu infections. Dairy farmers don’t get compensated for reporting infections, which incentivizes producers to keep quiet, upping the risk that outbreaks get out of hand and spread to other cattle or farm workers.

This presents a major problem for tracking the spread of the disease. “From the perspective of a producer, how is it going to benefit them to share or even test and understand if there’s a virus circulating in their herd?” Lawler says.

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May 3, 2024
How the US is preparing for a potential bird flu pandemic

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Dairy cows at a farm in the US

Shutterstock / Roman Melnyk

As a bird flu virus continues to spread among dairy cattle in the US, the country’s health agencies are actively preparing for the possibility of an outbreak in people.

“The risk [of bird flu] remains low at this time, but we continue to be in a strong readiness posture as new data becomes available,” said Vivien Dugan at the US Centers for Disease Control and Prevention (CDC) at a meeting of health officials on 25 April.

A top priority is tracking the virus’s spread. So far, the US Department of Agriculture (USDA) has confirmed H5N1, a subtype of the bird flu virus, in dairy cows on 33 farms across eight states, and in six cats on farms in three of those states.

Genetic sequencing found that only one of the 260 samples from sick dairy cows so far has a mutation indicating H5N1 has adapted to infecting mammals, said Rosemary Siffor d at the USDA during the meeting. However, this marker has been seen before in other sick mammals, and it didn’t impact the ability of the virus to transmit between mammals. Plus, the other 10 samples from the same herd where this one was collected didn’t have the same mutation.

“It very much remains an avian virus with no significant changes… In other words, it is not becoming a [cow] virus,” said Sifford.

The CDC has tested 23 people with close contact to the animals for the virus, according to data presented at the meeting. Only one of them was positive – a dairy worker in Texas whose only symptom was eye redness. To boost testing capabilities, the CDC recently increased funding to genetic sequencing centres in six states, said Dugan.

Another key measure being taken is ensuring the safety of the milk supply in the US. Milk from infected cattle contains high amounts of the virus. While milk from sick animals shouldn’t be entering the milk supply, initial testing from the US Food and Drug Administration (FDA) found that 1 in 5 milk samples contain genetic traces of bird flu.

“Importantly, that doesn’t mean the samples contain intact, infective virus,” said Donald Prater at the FDA. The testing method used detects any genetic material, including that of dead virus.

The vast majority of milk sold in the US is pasteurised, a process that kills pathogens with high heat. No study has assessed pasteurisation’s effectiveness against H5N1, but studies of similar influenza viruses suggest it would be, said Prater. This is why people should avoid consuming or touching raw milk products.

Two vaccine candidates for H5N1 are also in the works. Initial testing by the CDC indicates both are effective in lab tests against the current strain in cattle, said Dugan.

As part of a pre-established protocol, the US Administration for Strategic Preparedness and Response (ASPR) is stockpiling materials for a bird flu vaccine, said David Boucher at ASPR in the meeting. This includes manufacturing the part of the vaccine, called the antigen, that mounts an immune response to the virus. ASPR and its commercial partners have already filled hundreds of thousands of vaccines for H5N1 that, if needed, can be quickly dispensed for clinical testing or emergency use, he said.

“Based on the CDC’s current risk of the situation, vaccination is not a tool needed at this time. We do want to be ready if that changes, though,” said Boucher. Enough material is stockpiled to churn out an additional 10 million doses, too. And ASPR has contracts with vaccine manufacturers to ramp up production even more so if necessary.

“If we need to pull any of these levers, we are ready to do so,” said Boucher.

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April 26, 2024
What is Disease X and do we need to worry about it?

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What is Disease X?

Don’t panic! Disease X doesn’t exist yet – but it might one day. Disease X is the label that the World Health Organization uses to refer to some currently unknown infectious condition that is capable of causing an epidemic or – if it spreads across multiple countries – a pandemic. The term, coined in 2017, can be used to mean a newly discovered pathogen or any known pathogen with newly acquired pandemic potential. By the latter definition, covid-19 was the first Disease X. But there could be another in the future.

Why are people talking about it now?

The World Health Organization has been warning global leaders about the risks of future pandemics at the World Economic Forum’s annual meeting. “Some people say this may create panic,” says WHO director-general Tedros Adhanom Ghebreyesus. “No. It’s better to anticipate something that may happen – because it has happened in our history many times – and prepare for it.”

What might the next Disease X be?

We don’t know – that is why it is called Disease X. The coronaviruses, a large group of viruses, were long seen as a prime contender for producing a new pandemic, even before the covid-19 outbreak. That is because the novel coronavirus wasn’t the first dangerous pathogen from this group. In 2002, a different coronavirus started spreading in China. It caused a form of pneumonia called SARS that killed around 1 in 10 of those it infected, before it was stopped by strict infection control measures. Another, even deadlier coronavirus called MERS occasionally breaks out, causing a pneumonia that kills 1 in 3 of those infected. However, recent work suggests SARS and MERS would have a harder time triggering a fresh pandemic because almost everyone in the world now has antibodies to the virus that causes covid-19 and these seem to give partial protection against most other pathogens in the coronavirus family.

Are there any other contenders with pandemic potential?

Plenty of diseases, some well known and others less familiar, could pose a global threat. Flu strains have caused global pandemics several times in the past, including one of the deadliest disease outbreaks ever, the “Spanish flu” of 1918. A virulent strain of bird flu is currently sweeping the world, and it occasionally spreads from birds to mammals, causing mass die-offs. Just this week, it was named as the culprit in the deaths of 17,000 baby elephant seals in Argentina last October. Then there are other contenders, such as Ebola, which causes severe bleeding, and the mosquito-borne Zika, which can cause babies to born with smaller heads if the infection occurs during pregnancy. The WHO updated its list of pathogens with the most pandemic potential in 2022.

What can we do to stop Disease X?

There is some good news: the covid-19 pandemic may have made it easier to stop any future Disease X. Covid-19 spurred the development of novel vaccine designs, including ones that can be quickly repurposed to target new pathogens. It led, for instance, to the advent of vaccines based on mRNA. This formula contains a short piece of genetic material that makes the body’s immune cells produce the coronavirus “spike” protein – but it could be updated to make cells churn out a different protein, simply by rewriting the mRNA sequence.

Can we do anything else to fight against Disease X?

Countries need better early warning systems for new diseases, and health services need to become more resilient to unexpected surges in demand, says Tedros. “When hospitals were stretched beyond their capacity [with covid], we lost many people because we could not manage them. There was not enough space, there was not enough oxygen.” To prevent the same thing from happening when Disease X strikes, Tedros says health services must be able to expand their capacity on demand. Luckily, they can make those preparations without knowing exactly what Disease X will be. “Disease X is a placeholder,” he says. “Whatever the disease is, you can prepare for it.”

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April 4, 2024
Bird flu confirmed in person who had contact with infected dairy cows

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Dairy cows

Shutterstock / Yuangeng Zhang

A person in the US has contracted bird flu from infected dairy cows in Texas. This is the first confirmed case of a subtype of the virus, named H5N1, transmitting between a human and another mammal.

The US Centers for Disease Control and Prevention (CDC) announced the news today after confirming the positive test results over the weekend. The person, whose only symptom is eye inflammation, is on antiviral medications and recovering. They had been exposed to cows believed to be infected with the virus, which has decimated global bird populations.

Last week, cows across five US states – Texas, Kansas, Michigan, New Mexico and Idaho – tested positive for H5N1. It is unclear how they became sick, but it now seems that the virus may be spreading among the animals, according to the US Department of Agriculture.

Previously, mammals had only been confirmed to contract the virus from sick birds. “There have been a couple of outbreaks that didn’t include humans where it is possible there was mammal-to-mammal transmission,” says Richard Webby at St. Jude Children’s Hospital in Tennessee. For instance, 17,000 baby elephant seals died from bird flu in Argentina late last year. There was also an outbreak among farmed mink in Spain in 2022. But it is hard to rule out the possibility of other sources of the virus such as contaminated food in these situations, he says.

Despite the recent human infection, the CDC says the risk of contracting bird flu remains low for most people. People in close contact with infected birds or other animals, including livestock, have the greatest risk. While pasteurised milk remains safe, people should avoid consuming or handling raw milk products.

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April 1, 2024