On July 23, local time, the World Health Organization (WHO) announced that the monkeypox epidemic that has spread in 75 countries and regions has constituted a "public health emergency of international concern", which is the highest level of public health alert that the WHO can currently issue.
(Source: MIT Technology Review)
Last month, Stanford's Sewer Coronavirus Alert Network ( SCAN ) included monkeypox in its daily routine of wastewater virus testing , the only organization that detects monkeypox in U.S. wastewater and publishes it.
Since then, 10 of the 11 sewer systems covered by SCAN have found monkeypox, including Sacramento, Palo Alto and several other cities in the California Bay Area.
As of July 21, US time, 2593 cases of monkeypox have been recorded in the United States. Globally, the virus has been detected in 74 countries, 68 of which monkeypox has never occurred.
SCAN began monitoring COVID-19 in California wastewater in 2020. It is currently the only public job in the United States to detect monkeypox in showers, sinks and toilet wastewater. It absorbs sewage from untreated wastewater through solids and then extracts genetic material from it in order to understand the spread of the virus or bacteria at the community level, as well as the prevalence of the outbreak.
Over the past two years, the concentration of COVID-19 in wastewater has reflected the changing trend of COVID-19 cases – in line with the trend of confirmed cases. Wastewater surveillance at the end of 2021 showed that the Omiljung variant was circulating in the United States much earlier than reported clinical cases.
Alexandria Boehm, co-director of SCAN and a professor at Stanford University who studies pathogen transmission, said early data suggested that the concentration of monkeypox in wastewater could also tell us about monkeypox cases in our communities.
Now, by modeling the correlation between wastewater data and monkeypox cases over the past month, Bohm and colleagues are working to use wastewater data to estimate the number of people in the community who actually have monkeypox.
This estimate can be updated daily, which is a better way to track community transmission than waiting for symptomatic patients to see a doctor and get tested.
Unlike coronavirus testing, the skin of a monkeypox patient must already have boils before a doctor can test with a swab, which appears 1 to 2 weeks after infection. Wastewater monitoring can help people detect monkeypox infections earlier.
This approach is particularly useful when there is a bottleneck in clinical testing. Everyone is having a bowel movement, but very few are tested for monkeypox. Prior to June 22, only about 70 of the more than 200 Centers for Disease Control and Prevention laboratories nationwide were authorized to test for monkeypox. Five companies are currently authorized to conduct monkeypox testing, but it will take time to scale up.
Due to the lack of accurate data on monkeypox infection, it is difficult to build a model that can use wastewater to estimate monkeypox cases. At the same time, in the absence of detection data, the real relationship between the two is more difficult to establish.
Monkeypox belongs to the same virulent family as smallpox, but is less contagious and usually has milder symptoms. It's still unpleasant — except for flu-like symptoms, monkeypox is signs of pus-filled blisters on the face, hands, feet or genitals. If you rinse the ulcer wound with water while showering or washing your hands, monkeypox DNA is carried into the wastewater.
Recent data suggest that monkeypox DNA can also be detected in various bodily fluids of infected people. This includes respiratory and nasal secretions, saliva, urine, feces and semen – meaning that wastewater testing can also take advantage of a patient's secretions and excrement.
If a pathogen's genetic footprint can persist in wastewater for more than 24 hours, SCAN is likely to detect it. COVID-19 RNA can persist in wastewater for up to 10 days. While monkeypox DNA appears to last longer than 24 hours, there is no publicly available study of how long it can last.
Another question is how much monkeypox DNA is needed to enter the wastewater system for SCAN to actually detect it. For comparison, scans can catch traces of the virus from the wastewater that covers 100,000 people with only 2 COVID-19 patients.
Even in a state like California that separates sewage and drainage systems, rainwater dilutes the concentration of viral DNA in wastewater. In response, SCAN normalized its estimates using a mild-spotted virus with a definite expected number.
Healthy humans excrete harmless viruses after eating pepper and pepper-based foods, making them the most abundant RNA viruses in human feces. This makes it easier for people to track because it is also very stable in the water.
Figure | Scan electron microscopy photo of monkeypox virus (orange) on infected cells (green) (Source: National Institute of Allergy and Infectious Diseases)
There is no evidence that humans contract monkeypox from wastewater. According to the WHO, human-to-human transmission of monkeypox virus presupposes long-term close contact with an infected person, direct exposure to their rash, body fluids or respiratory droplets. Bedding and clothing for monkeypox patients can also transmit the virus.
Currently, monkeypox vaccines already exist, and the smallpox vaccine in the U.S. national stockpile provides protection. However, public access to monkeypox testing, treatment and vaccines remains limited. Inspecting wastewater can help public health officials conduct extensive surveillance in the absence of a monkeypox outbreak and help determine where to put more medical resources.
Wastewater monitoring can also detect new monkeypox variants, two of which are already endemic in the United States. Almost all of the current outbreaks are driven by West African strains of monkeypox, which SCAN has specifically tested. This strain is more contagious, but the mortality rate is much lower than other strains, such as the Congo Basin branch (strain).
In recent years, monkeypox has killed 3 to 6 percent of infected people, and it is more deadly in children. This year, monkeypox has killed 3 people worldwide.
SCAN is currently the only effort to publish monkeypox data in wastewater. "The Bay Area is at the forefront of wastewater monitoring because we're Silicon Valley after all," Bohm said. But that doesn't mean there aren't monkeypox in wastewater elsewhere. ”
Supported: Ren
Original:
https://www.technologyreview.com/2022/07/23/1056399/monkeypox-california-wastewater/