When there is a new disease discovered, scientists called epidemiologists work to find out why the area or a person has a new disease, and what the health departments can do about it. From the start of the pandemic, COVID-19 epidemiologists across the world have been working to:
1. Identify the Source of the Outbreak
Covid-19 epidemiologists went into the region in China, where the new disease first appeared and conducted surveys in health facilities and the community. Throat and nose specimens gathered for lab analysis.
These Covid-19 epidemiology field investigations showed them who was infected, when they became infected, and where they had been just before they got sick—and eventually led them to a possible source.
2. Monitor and Track the Infection
The health departments keep track of the number of COVID-19 cases and gather information on the disease from surveillance programs that report various sorts of information, such as new cases, deaths, hospitalizations, demographic information (such as gender, or age, race/ethnicity), symptoms, and remedies.
3. Study the Disease
The scientists use surveillance information, including information from antibody testing and other types of studies, to discover more about the disease, like how long a person with COVID-19 is infectious, risk factors for acute illness, and which medical treatments are best.
Develop guidelines for activities to impede the spread of this disease and lessen its impact on the communities. Using study findings, case counts, and surveillance then publishes resources to help people in different risk groups (such as older people or healthcare workers) stay safe in different settings (like home, grocery stores, or school). These guidelines are regularly being updated as new information becomes available.
Agency Research Studies
CDC and other agencies and associations worldwide, like WHO, are conducting thousands of research projects to find out more about COVID-19 and the virus origins. These studies help us understand:
A) The duration between when someone is exposed to the virus and when they have symptoms (incubation period). We know now know that someone can be infected with the coronavirus for 2–14 days before they feel sick and that some people never feel ill.
B) Just how long a person is infected may shed (discharge from the body) the virus. To prevent spreading disease, we recommend that individuals infected with the COVID-19 avoid being around others until they’ve gone 3 days without fever, their symptoms have gone, and 10 days have passed since their symptoms began.
C) The range of symptoms, signs, and severity of the disease – Knowing this information helps individuals watch for early symptoms and assist healthcare professionals in diagnosing and treating the disease.
D) The risk factors associated with severe disease – We know that individuals who are elderly or have severe chronic health conditions are at higher risk of becoming very sick from COVID-19.
E) The disease causes death and sickness in a population (mortality and morbidity rate) – This information helps epidemiologists understand COVID-19 impacts on health.
A cohort study keeps track of a group of individuals (the cohort) over time. If the information is already collected for different purposes, it’s a retrospective cohort study.
These results help health professionals prioritize COVID-19 prevention methods for people who might be at increased risk for severe disease by prioritizing finance, test and additional studies in those communities and developing particular clinical guidelines based on differences in resources to reduce the spread in these communities.
In a prospective cohort study, the data collection starts when a cohort is made, and the data are gathered from that group going forward. Existing COVID-19 studies are looking at:
- The severity of illness and risk factors for severe disease,
- Knowledge, attitudes, and practices of a particular population (such as Pregnant women or individuals with underlying medical conditions),
- Use of certain medicines
- Infection prevention and control practices.
- Serology Surveys
- Medic taking a sample for COVID-19 testing
Individuals who have been tested positive with a virus may develop antibodies (which are proteins in the blood to combat the virus) even if they don’t know they’re infected. Serologic tests may be used to detect the antibodies.
By counting the number of individuals with antibodies to COVID-19, experts can discover how much the infection has spread in a community. Antibody tests are useful. They include diseases that may have been overlooked because people had no symptoms (were asymptomatic) or moderate symptoms and therefore didn’t get tested or get medical attention.
Antibody tests help solve other vital questions about how COVID-19 infections are progressing through populations with time and estimate how much of the populace hasn’t yet been infected, supporting public health officials’ plans for health care needs.
The COVID-19 seroprevalence surveys include large-scale geographical surveys, community-level surveys, and surveys focusing on particular populations.
Identifying the Source of the Outbreak
The new coronavirus that first appeared in China had never been seen before, so it quickly gained the interest of scientists worldwide. Epidemiologists did field investigations to discover how the new virus started.
They performed surveys in the community and in health centers and accumulated nose and throat specimens for laboratory analyses. These investigations showed who had been infected when they became ill and where they were just before they got sick.
Covid-19 epidemiologists concluded that the virus possibly came from an animal sold in a wet market. The new virus was shown to be a coronavirus, and coronaviruses cause severe acute respiratory syndrome. This new coronavirus is much like SARS-CoV, so it was called SARS-CoV-2. The disease brought on by the virus was called COVID-19 (COronVIrusDisease-2019) to demonstrate that it had been discovered in 2019.
An outbreak is known as an epidemic when there is a sudden rise in cases. Since COVID-19 began spreading in Wuhan, China, it became an epidemic. Since the disease then spread across many countries and influenced millions of individuals, then it was categorized as a pandemic.
Monitoring and Tracking the Infection
As the coronavirus began to spread from person to person in communities (community transmission), scientists had to monitor the disease and attempt to slow its spread. To accomplish this, they had a standard definition for a case of COVID-19.
Having a case definition can help to ensure cases are counted the same way everywhere. In America, a confirmed case of COVID-19 is described as an individual who tests positive for the virus, which causes COVID-19.
COVID-19 turned into a worldwide notifiable disease, meaning that health departments are expected to report cases of COVID-19. Systems such as the National Notifiable Diseases Surveillance System (NNDSS) in America gather and send information on cases of COVID-19 to the government. This assists the CDC agency track trends in cases across the nation and within countries.
As cases of COVID-19 are being found, epidemiologists are administering public health surveillance, the systematic collection, analysis, and interpretation of health data. Surveillance grants epidemiologists to find out:
- Incidence (number of new cases coming over a specific period).
- Prevalence (number of instances at a particular point in time).
- Hospitalizations (number of cases leading to hospitalization).
- Deaths (number of cases leading to death).
But surveillance is not just about counting cases. All sorts of information can be gathered to find out more about the disease.
Gathering data from medical records (chart abstractions) can provide us more information about COVID-19 patients and the course of their disease. These data may include demographic information (age, race/ethnicity, sex) and symptoms, treatments, and health effects. Scientists can use graph abstractions to learn who is likely to become ill, what care patients have obtained, and when patients have recovered.
After scientists analyze and collect the information, expert visualization helps create graphics, charts, and images to make the information use easier to understand. This information isn’t only beneficial for Covid-19 epidemiologists working to understand the information but also for the public.
An epi curve is often included by displays of epidemiological data. An epi curve shows what’s happened, such as the number of cases, hospitalizations, or deaths over time. Epi curves for COVID-19 are being updated as new information becomes available.
As there is a delay between when someone gets ill and when that person’s case is reported, it can be challenging to determine when cases actually start to decline. An epi curve for the most recent weeks may seem like an outbreak is ending when it’s still active. The full shape of the curve is only evident after the outbreak is over.
Public health workers and researchers are currently working to stop the spread of COVID-19 through contact tracing. In this plan, public health workers talk to patients with COVID-19 to find about all the people they were physically close to while they were possibly able to spread the disease.
Those folks are their contacts. With this data, scientists can follow the disease chain to learn how the virus might have spread from one person to another. Contact tracing helps to prevent and control many other infectious diseases, such as HIV and tuberculosis.
Using the information discovered through contact tracing, epidemiologists develop tables, known as line lists, compiling the data about the contacts. The connection between each person is known as an epidemiological (epi) link.
Contacts of people with COVID-19 are at higher risk for contracting the disease and spreading it to others.
Public health employees reach out to those at risk to tell they’ve had contact with COVID-19, and as a result of this vulnerability, they may get sick. They recommend prevention measures contacts should follow, such as self-quarantine (remaining away, from others while tracking themselves for signs of illness), handwashing, and using cloth face coverings.
Contact tracing has helped reduce the speed spread of epidemics, Including SARS and Ebola, and is vital in reducing the spread of COVID-19.
Impact of Disease
A key part of epidemiologists throughout the COVID-19 pandemic would be to understand the disease’s burden: the effect of a disease or other health effects on a population. As scientists gather data from the COVID-19 researches, they examine these data to assess key outcomes, such as the number of illnesses, infections, hospitalizations, medical visits, and deaths.
Growing Guidance to Protect the Public’s Health
The WHO protects the health of communities throughout the world. Since the early days of the pandemic, Covid-19 epidemiologists have been utilizing information from different types of studies, they’ve discussed developing evidence-based advice, like wearing N95, cloth, or surgical masks to protect against the spread of this virus. These are intended for various audiences, such as:
- Healthcare providers and health departments,
- Laboratory scientists,
- Healthcare and long-term care facilities,
- Schools and businesses,
- First responders,
- Pregnant individual and parents,
- Pet owners.
COVID-19 guidelines offer advice for all these groups to slow the spread of this disease and protect their health.
- clinical care,
- preparedness in healthcare facilities,
- personal prevention measures,
- case reporting,
- personal protective equipment (PPE), and
- Daily life and coping.
Why COVID-19 Forecasting Is Important
Covid-19 Epidemiologists are currently responding to a pandemic caused by the new coronavirus, SARS-CoV-2, trying to slow the spreading from person to person. The WHO and many national governments are working closely with local, state, tribal, and territorial health departments, and other public health associates, to respond to this situation. Forecasts of hospitalizations and deaths can help inform public health decision making by projecting the likely effect of the COVID-19 pandemic in the coming weeks.
Epidemiologist Bringing Forecasts for COVID-19 Hospitalizations and Deaths
WHO and other government agencies work together with partners to bring weekly forecasts based on mathematical or statistical models that aim to forecast:
-National and state numbers of total COVID-19 deaths for the next 4 weeks.
-National and state numbers of COVID-19 hospitalizations daily for the next 4 weeks.
Forecasting companies predict numbers of hospitalizations and deaths using different kinds of information (e.g., COVID-19 data, demographic information, mobility data), methods, and estimates of the consequences of interventions (e.g., use of face coverings, social distancing). These forecasts are developed independently and shared publicly. It’s essential to bring these predictions to help know how they compare with each other and how much uncertainty there is about what may happen shortly.