During January 1, 2020–May 18, 2020, approximately 1.3 million cases of coronavirus disease 2019 (COVID-19) and 83,000 COVID-19–associated deaths were reported in the United States (1). Understanding the demographic and clinical characteristics of decedents could inform medical and public health interventions focused on preventing COVID-19–associated mortality. This report describes decedents with laboratory-confirmed infection with SARS-CoV-2, the virus that causes COVID-19, using data from 1) the standardized CDC case-report form (case-based surveillance) (https://www.cdc.gov/coronavirus/2019-ncov/php/reporting-pui.html) and 2) supplementary data (supplemental surveillance), such as underlying medical conditions and location of death, obtained through collaboration between CDC and 16 public health jurisdictions (15 states and New York City).


Case-based surveillance

Demographic and clinical data about COVID-19 cases are reported to CDC from 50 states, the District of Columbia, New York City, and U.S. territories using a standardized case-report form (case-based surveillance) or in aggregate. Data on 52,166 deaths from 47 jurisdictions among persons with laboratory-confirmed COVID-19 were reported individually to CDC via case-based surveillance during February 12–May 18, 2020. Among the 52,166 decedents, 55.4% were male, 79.6% were aged ≥65 years, 13.8% were Hispanic/Latino (Hispanic), 21.0% were black, 40.3% were white, 3.9% were Asian, 0.3% were American Indian/Alaska Native (AI/AN), 0.1% were Native Hawaiian or other Pacific Islander (NHPI), 2.6% were multiracial or other race, and race/ethnicity was unknown for 18.0%. (Table 1). Median decedent age was 78 years (interquartile range (IQR) = 67–87 years). Because information about underlying medical conditions was missing for the majority of these decedents (30,725; 58.9%), data regarding medical conditions were not analyzed further using the case-based surveillance data set. Because most decedents reported to the supplementary data program were also reported to case-based surveillance, no statistical comparisons of the decedent characteristics between the data sets were made.


Supplemental surveillance

To collect more complete data on race/ethnicity, selected underlying medical conditions* by age, and clinical course, CDC solicited supplementary information from medical charts and death certificates of decedents with laboratory-confirmed COVID-19 from state, territorial, and local public health departments. The supplementary data request also sought information on locations of death, which is not collected routinely on the CDC case-report form. Among 56 public health departments contacted by CDC, 16† provided supple­mentary data on 10,647 COVID-19 deaths that occurred during February 12–April 24, 2020.

Among the 10,647 COVID-19 decedents for whom supple­mentary data were collected, 60.6% were male, 74.8% were aged ≥65 years, 24.4% were Hispanic, 24.9% were black, 35.0% were white, 6.3% were Asian, 0.1% were AI/AN, 0.1% were NHPI, 2.9% were multiracial or other race, and race/ethnicity was unknown for 6.3% (Table 1). Decedent age varied by race and ethnicity; median age was 71 years (IQR = 59–81 years) among Hispanic decedents, 72 years (IQR = 62–81 years) among all nonwhite, non-Hispanic decedents, and 81 years (IQR = 71–88 years) among white decedents. The percentages of Hispanic (34.9%) and nonwhite (29.5%) decedents who were aged <65 years were more than twice those of white decedents (13.2%) (Figure).

At least one underlying medical condition was reported for 8,134 (76.4%) of decedents for whom sup­plementary data were collected, including 83.1% of decedents aged <65 years. Overall, the most common underlying medical conditions were cardiovascular disease (60.9%), diabetes mellitus (39.5%), chronic kidney disease (20.8%), and chronic lung disease (19.2%) (Table 2). Among decedents aged <65 years, 83.1% had one or more underlying medical conditions. Among decedents aged ≥85 years, 69.5% had one or more underlying medical conditions. Diabetes was more common among decedents aged <65 years (49.6%) than among those aged ≥85 years (25.9%).

Among decedents for whom supplementary data were reported, 8,976 (84.3%) were hospitalized. Among 3,021 (28.4%) with dates of illness onset and death reported, the median interval from illness onset to death was 10 days (IQR = 6–15 days); among 7,794 decedents with hospital admission and death dates, the median interval from hospital admission to death was 5 days (IQR = 3–8 days). Among the decedents, 62.0% died in hospitals. By age group, the largest percentage who died in the emergency department (6.8%) or at home (1.0%) was aged <65 years (combined total = 7.8%), and decreased with increasing age group, whereas the percentage who died in long-term care facilities increased with increasing age and was highest among decedents aged ≥85 years (12.6%).

Among the decedents during February 12–April 24, 2020, for whom supplementary information was provided, 9,997 (93.9%) resided in New York City, New Jersey, or the state of Washington, three areas with early widespread circulation of SARS-CoV-2; the median age among decedents in these three jurisdictions was 75 years, (IQR = 64–84 years). The median age among decedents residing in the other 13 jurisdictions was similar (78 years, [IQR = 68–85 years]).


Discussion

Using national case-based surveillance and supplementary data reported from 16 jurisdictions, characteristics of >10,000 decedents with laboratory-confirmed COVID-19 were described. More than one third of Hispanic decedents (34.9%) and nearly one third (29.5%) of nonwhite decedents were aged <65 years, but only 13.2% of white decedents were aged <65 years. Consistent with reports describing the characteristics of deaths in persons with COVID-19 in the United States and China (2–5), approximately three fourths of decedents had one or more underlying medical conditions reported (76.4%) or were aged ≥65 years (74.8%). Among reported underlying medical conditions, cardiovascular disease and diabetes were the most common. Diabetes prevalence among decedents aged <65 years (49.6%) was substantially higher than that reported in an analysis of hospitalized COVID-19 patients aged <65 years (35%) and persons aged <65 years in the general population (<20%) (5–7). Among decedents aged <65 years, 7.8% died in an emergency department or at home; these out-of-hospital deaths might reflect lack of health care access, delays in seeking care, or diagnostic delays. Health communications campaigns could encourage patients, particularly those with underlying medical conditions, to seek medical care earlier in their illnesses. Additionally, health care providers should be encouraged to consider the possibility of severe disease among younger persons who are Hispanic, nonwhite, or have underlying medical conditions. More prompt diagnoses could facilitate earlier implementation of supportive care to minimize morbidity among individuals and earlier isolation of contagious persons to protect communities from SARS-CoV-2 transmission.

The relatively high percentages of Hispanic and nonwhite decedents aged <65 years were notable. The median age of nonwhite persons (31 years) in the United States is lower than that of white persons (44 years); these differences might help explain the higher proportions of Hispanic and nonwhite decedents among those aged <65 years. The median ages among Hispanic and nonwhite decedents (71 and 72 years, respectively) were 9–10 years lower than that of white decedents (81 years). However, the percentage of Hispanic decedents aged <65 years (33.9%) exceeded the percentage of Hispanic persons aged <65 years in the U.S. population (20%); the percentage of nonwhite COVID-19 decedents aged <65 years (40.2%) also exceeded the overall percentage of nonwhite decedents aged <65 years (23%) in the U.S. population (8). Further study is needed to understand the reasons for these differences. It is possible that rates of SARS-CoV-2 transmission are higher among Hispanic and nonwhite persons aged <65 years than among white persons; one potential contributing factor is higher percentages of Hispanic and nonwhite persons engaged in occupations (e.g., service industry) or essential activities that preclude physical distancing (9). It is also possible that the COVID-19 pandemic disproportionately affected communities of younger, nonwhite persons during the study period (10). Although these data did not permit assessment of interactions between race/ethnicity, underlying medical conditions, and nonbiologic factors, further studies to understand and address these racial/ethnic differences are needed to inform targeted efforts to prevent COVID-19 mortality.

The findings in this report are subject to at least five limitations. First, despite >90% completeness for age and race/ethnicity variables in the supplementary data set, the proportion of missing data for some variables, such as underlying medical conditions, clinical course, and race/ethnicity in case-based surveillance, and location of death, was higher than that for other variables; accordingly, the proportions reported for these variables should be considered minimum proportions rather than robust estimates. Second, reporting practices varied by jurisdiction, and several states bundled underlying medical conditions into organ system–specific categories (e.g., hypertension was included as cardiovascular disease) or did not code specifically for a given condition (e.g., immunosuppression was only specifically coded in 10 of the jurisdictions). These differences in reporting structure precluded evaluations of specific conditions other than diabetes using the entire data set. Third, generalizability of the findings from either data set to all deaths among persons with COVID-19, either within the individual jurisdictions or across the United States, is unknown; COVID-19 testing practices for decedents might differ among jurisdictions. Fourth, information from the supplementary data set provides additional insight into decedent demographic and clinical characteristics; however, these data are a convenience sample from 16 public health jurisdictions. Therefore, because the age-race structure of the underlying population is not known, age-standardized mortality rates could not be calculated. Although more than 90% of decedents resided in just three jurisdictions, and most are represented in case-based surveillance, they represent a subset of deaths reported during this period. Therefore, neither calculations of mortality rates nor statistical comparisons between the demographic characteristics of the decedents with available supplementary data and those from case-based surveillance were possible. Finally, these data were collected during a period before dexamethasone was shown to reduce deaths among ventilated patients; implementation of dexamethasone and other therapeutics, as well as shifts in the ages of patients and geographic locations of cases might affect the generalizability of these data to the current period.China denies 'cover-up' after Wuhan COVID-19 deaths rise 50 ...

Despite these limitations, this report provides more detailed demographic and clinical information on a subset of approximately 10,000 decedents with laboratory-confirmed COVID-19. Most decedents were aged >65 years and had underlying medical conditions. Compared with white decedents, more Hispanic and nonwhite decedents were aged <65 years. Additional studies are needed to elucidate associations between age, race/ethnicity, SARS-CoV-2 infection, disease severity, underlying medical conditions (especially diabetes), socioeconomic status (e.g., poverty and access to health care), behavioral factors (e.g., ability to comply with mitigation recommendations and maintain essential work responsibilities), and out-of-hospital deaths. Regional and state level efforts to examine the roles of these factors in SARS-CoV-2 transmission and COVID-19-associated deaths could lead to targeted, community-level, mortality prevention initiatives. Examples include health communication campaigns targeted towards Hispanics and nonwhite persons aged <65 years. These campaigns could encourage social distancing and the need for wearing cloth face coverings in public settings. In addition, health care providers should be encouraged to consider the possibility of disease progression, particularly in Hispanic and nonwhite persons aged <65 years and persons of any race/ethnicity, regardless of age, with underlying medical conditions, especially diabetes.

CDC-Characteristics of Persons Who Died with COVID-19 — United States

Fermentation media are used to differentiate organisms based on their ability to ferment carbohydrates incorporated into the basal medium.Phenol Red Broth Medium with various added carbohydrates serves as a differential medium by aiding in differentiation of various species and genera by their ability to ferment the specific carbohydrate, with the production of acid or acid and gas.The carbohydrate source can vary based on test requirements. The common broth media used are:Phenol Red Glucose BrothPhenol Red Lactose BrothPhenol Red Maltose BrothPhenol Red Mannitol BrothPhenol Red Sucrose Broth
Objective
To determine the fermentation reactions of pure cultures of microorganisms.
Principle
Carbohydrate fermentation is the process microorganisms use to produce energy. Most microorganisms convert glucose to pyruvate during glycolysis; however, some organisms use alternate pathways. A fermentation medium consists of a basal medium containing a single carbohydrate (glucose, lactose, sucrose, mannitol etc.) for fermentation. However, the medium may contain various color indicators. In addition to a color indicator to detect the production of acid from fermentation, a Durham tube is placed in each tube to capture gas produced by metabolism. The carbohydrate fermentation patterns shown by different organisms are useful in differentiating among bacterial groups or species.
Media
Phenol Red Broth is a general-purpose differential test medium typically used to differentiate gram negative enteric bacteria.  It contains peptone, phenol red (a pH indicator), a Durham tube, and one carbohydrate (glucose, lactose, or sucrose). Phenol red is a pH indicator which turns yellow below a pH of 6.8 and fuchsia above a pH of 7.4. If the organism is able to utilize the carbohydrate, an acid by-product is created, which turns the media yellow.  If the organism is unable to utilize the carbohydrate but does use the peptone, the by-product is ammonia, which raises the pH of the media and turns it fuchsia. When the organism is able to use the carbohydrate, a gas by-product may be produced. If it is, an air bubble will be trapped inside the Durham tube.  If the organism is unable to utilize the carbohydrate, gas will not be produced, and no air bubble will be formed.
Method
Aseptically inoculate each test tube with the test microorganism using an inoculating needle or loop. Alternatively, inoculate each test tube with 1-2 drops of an 18- to 24-hour brain-heart infusion broth culture of the desired organism.Incubate tubes at 35-37°C for 18-24 hours.Check for color changes or formation of gas.
Result Interpretation
I. Acid production:
Positive: After incubation the liquid in the tube turns yellow (indicated by the change in the color of the phenol red indicator). It indicates that there is drop in the pH because of the production of the acid by the fermentation of the carbohydrate (sugar) present in the media.Negative:The tube containing medium will remain red, indicating the bacteria cannot ferment that particular carbohydrate source present in the media.
II. Gas Production
Positive:A bubble (small or big depending up the amount of gas produced) seen in the inverted Durham tube.Negative: No bubble in the inverted Durham tube i.e. bacteria does not produce gas from the fermentation of that particular carbohydrate present in the media i.e. anaerogenic organism.
Uses
It is recommended to determine the fermentation reaction of carbohydrates for the differentiation of microorganisms.It is useful in identifying Gram negative bacilli, especially Enterobacteriaceae.
Limitations
Phenol Red Broth test is not intended for use in the diagnosis of disease or other conditions in humans.Due to nutritional variation, some strains may be encountered that grow poorly or fail to grow on this medium.The addition of some carbohydrates to the basal medium may result in an acid reaction. To ensure accuracy of interpretation, uninoculated control tubes and/or inoculated Phenol Red Broth Base control tubes should be run in parallel with the fermentation tests.

Phenol Red Fermentation Test – Principle, Procedure, Uses and Interpretation

The report in Nature Medicine suggests that if validated in larger trials and applied widely, the noninvasive test could find more early kidney cancers when they haven’t spread, thus reducing the mortality of the disease. “Hopefully we can scale this to a much larger level and detect cancer earlier so we can act earlier,” said Toni Choueiri, director of the Lank Center for Genitourinary Oncology at Dana-Farber and a co-senior author of the study.

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It is estimated that 73,750 new kidney cancer cases will be diagnosed in 2020, and about 14,830 will die of the disease. About 35 percent of cancers are diagnosed only after they have spread beyond the kidney and are more difficult to treat. Small, early kidney tumors usually cause no symptoms, and increasingly are found incidentally in scans of the abdomen performed for another purpose. However, there is no imaging or other screening test recommended for the general population to look for early kidney cancers. Initially, a test based on the method described in the new report might be used to screen people with a family history of kidney cancer, or who had a previous kidney cancer, said Choueiri. “We need to be specific first, before making it totally mainstream,” he said.
Noninvasive liquid biopsies, which search for cancer-related DNA shed by tumors into blood or other body fluids, are moving rapidly toward clinical use as a means of early detection for some kinds of tumors. “Kidney cancer is one of the hardest tumors to detect, because it doesn’t shed as much DNA as other tumors,” said Matthew Freedman, a medical oncologist at Dana-Farber and co-senior author of the report.
The test performs well because it can identify abnormal patterns in small amounts of tumor-shed DNA, Freedman added. “It’s a proof of principle that early stage disease is detectable.”
The test was nearly 100 percent accurate when used with blood samples to distinguish patients with kidney cancer from those known to be free of kidney cancer. The method achieves less accuracy in testing urine samples, but the researchers believe that performance can be improved. If the test is validated in larger trials and becomes widely applicable clinically, a urine sample would be even less invasive than a blood draw.
The testing method is known as cell-free methylated DNA immunoprecipitation and high-throughput sequencing, or cfMeDIP-seq. Where other liquid biopsy methods search for mutations in tumor-shed DNA that reveal the type and location of cancer, cfMeDIP-seq detects abnormal methylation — the addition of chemical tags to DNA, which doesn’t alter their genetic code but can affect their function.
The method was tested on samples from 99 patients with early and advanced kidney cancer, 15 patients with stage IV urothelial bladder cancer, and 28 healthy, cancer-free control subjects. In analyzing blood serum with the test, the study reported “near-perfect” classification of patients across all stages of kidney cancer. While urine-based classification was not as accurate, the study authors claimed that “performance can be improved through technical and computational optimization.”

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Co-first authors of the report are Pier Vitale Nuzzo, Jacob E. Berchuck, Keegan Korthauer, and Sandor Spisak.
This study was conducted with support from Rebecca and Nathan Milikowsky, the Claudia Adams Barr Program for Innovative Cancer Research, the H.L. Snyder Medical Research Foundation, the Dana-Farber/Harvard Cancer Center Kidney SPORE and Program, the Kohlberg Chair at Harvard Medical School and the Trust Family, Michael Brigham, and Loker Pinard Funds for Kidney Cancer Research at Dana-Farber Cancer Institute.

Havard: A recent study found that a biomarker test is highly accurate in detecting early kidney cancer

Blowfly
When a body is discovered more than 72 hours after death, details normally examined to establish time of death such as body temperature, skin color, and degree of muscle rigidity, have all plateaued. Blowflies, however, lay eggs within minutes of someone dying and so investigators can use the growth timeline of blowfly maggots to find out exactly when a person died.

Life Cycle of the Blowfly

Though we use the term “blowfly” there are many different species with different growth charts and development timelines. Though adults are easy to tell apart, the maggots can look quite similar. Part of a forensic entomologist’s job is identifying which species the maggot belongs to and knowing how temperature and environment affects that growth. On average, though, the lifecycle of a blowfly goes through six stages. They are:
  1. Eggs Laid: Eggs are laid by a mature female blowfly in carcass holes or open wounds such as ears, nose, eyes, mouth, and anus within minutes of hours of death.
  2. Eggs Hatch (Larvae): Eggs are 1-2 mm in length and hatch after 24-45 hours then quickly grow to become first stage larvae, otherwise known as maggots.
  3. 1st Stage Maggots (Larvae): Maggots produce an enzyme that breaks down protein so they feed on semi-liquid bodily fluids as the body decomposes. At this stage they grow and after several days, shed their exoskeleton.
  4. 2nd Stage Maggots (Larvae): In the second maggot stage, they grow in size and continue to feed off the decomposing body. This stage ends when they molt for a second time and become third stage maggots.
  5. 3rd Stage Maggots (Pupae): In the third stage of maggots, now pupae, they fall to ground and no longer feed or move. Their exoskeleton hardens and turns from a light brown to a black color.
  6. Adult Blowfly: The adult blow fly emerges from the exoskeleton and can fly after only a few hours. A male blowfly is able to mate right away while a female must feed on protein such as a carcass or feces before being able to lay her own eggs and thus the cycle continues.

Blowfly Life Cycle

Blowflies Aid in the Decomposition Process

Blowflies often take a part in breaking down decomposing bodies and returning the nutrients back to the earth. It’s through their efforts that bodies decompose faster than they would otherwise.  Because of the specific life cycle of the blowflies, the time of death can be determined with fair level of certainty.   This is an important piece of information when investigating a death whether it’s an unattended death from natural causes, or when foul play is suspected.

Forensic:How maggot determine time of death

Some people are better protected than others against urinary tract infections. This may be because their bodies produce more of a protein called uromodulin. An interdisciplinary research team has now found out exactly how this helper protein brings relief when nature calls and how this knowledge might benefit the treatment and prevention of these painful inflammations.
Anyone who has ever had cystitis knows that urinary tract infections of this kind are annoying and painful. They can be well treated by antibiotics, but may be fatal if left untreated. These infections are usually caused by what are known as uropathogenic E. coli bacteria when they bind to the cells of the bladder, ureter or urethra with their pili, the thread-like appendages that grow out of them like hairs. But protection is at hand in the form of a certain protein, produced naturally in the body, called uromodulin. Around 70 percent of all people carry a uromodulin gene variant in their genome, which means that they produce this protective protein in particularly large quantities. Accordingly, they have a smaller risk of contracting urinary tract infections.
But the exact process by which uromodulin prevents inflammation had never been understood. Now an interdisciplinary team, drawn from three research groups at ETH Zurich together with researchers from the University of Zurich and the Children's Hospital Zurich, has filled this knowledge gap by investigating uromodulin's appearance and how the protein goes about neutralizing uropathogenic E. coli. Their findings, which have been published in the journal Science, should help to develop new strategies for the treatment of urinary tract infections in the future.
A detailed look at how it works
First, the researchers analyzed how the protein binds to the bacterial pili at the molecular level. "We already knew that a bond is formed and that this presumably plays a part in uromodulin's protective function, but nobody had studied this in greater detail," says Gregor Weiss, a doctoral student in molecular biology at ETH and one of the study's lead authors. Their biochemical investigations have now shown that the bacterial pili recognize certain sugar chains on the surface of the uromodulin and bind to them extremely readily and strongly.
Next, the team examined uromodulin using cryo-electron tomography, an imaging technique that produces three-dimensional views of the structure of proteins and cells with no need for chemical modification or dehydration. This showed them that uromodulin forms long filaments consisting on average of around 400 individual protein molecules strung together. And that each link of this protein chain contains the characteristic pattern of sugar chains to which bacterial pili like to bind.
Fruitful collaboration
Cryo-electron tomography was also the team's chosen technique for investigating at a larger scale what effect these properties have—this time in the presence of the culprits, the uropathogenic E. coli bacteria. They discovered that the uromodulin filaments literally envelop the pathogen, and that a single uromodulin filament can dock with several pili of a bacterium. "This neutralizes the pathogens," Weiss explains: "Once the bacteria are shielded in this way, they can no longer bind to the cells in the urinary tract, which means they can't cause infection." Under an optical microscope, the team also noted the formation of large clumps of hundreds of uromodulin filaments and E. coli cells, which are then presumably simply excreted with the urine.
Finally, the researchers checked to see whether all these processes they had observed in the laboratory also occur in patients. They analyzed urine samples from infected patients provided by the Children's Hospital in Zurich and found exactly the same interactions between uromodulin and the pathogens. "Without interdisciplinary collaboration between different research groups and institutes, it would have been impossible to obtain this set of findings," stresses ETH Professor Martin Pilhofer, who led the electron tomography investigations.
Pointers for treatment and drug development
The research team's work offers pointers for how to treat and prevent urinary tract infections without using antibiotics. Until now, patients have often been given preparations that contain the sugar mannose. To a certain extent, these prevent the E. coli bacteria from attaching themselves to the cells of the urinary tract. "Thanks to our analyzes, we now know that the bacterial pili recognize not only mannose but also other sugars present on uromodulin," says Jessica Stanisich, doctoral student and another lead author of the study. "This might indicate that treatment with combined sugar supplements would be more effective."
The new findings also help in the development of new active substances, adds ETH Professor Rudi Glockshuber. This is because during an infection the uropathogenic E. coli attach themselves to the same sugar chains on the cell surfaces of the urinary tract as on uromodulin. Pharmaceutical companies are looking to identify new active substances that will prevent precisely these interactions—but this risks also disrupting the protective binding of uromodulin to the bacteria. "It would obviously be a highly undesirable side effect for a drug if that treatment simultaneously interfered with a natural protective function," Glockshuber says. However, the research team's analyzes have now shown that the bonds between bacteria and uromodulin are extremely stable and cannot be broken down by active substances—an important finding in the search for remedies for unpleasant urinary tract infections.

How human body clear UTI without taking drug

See the source image
COVID-19 is an infectious disease caused by severe acute respiratory syndrome corona virus two(SARS-COV2). when the person is infected the most common sign include fever, cough, shortness of breath.
According to the World Health Organization (WHO), the WHO China Country Office was informed of cases of pneumonia of unknown etiology in Wuhan City, Hubei Province, on 31 December 2019. A novel coronavirus currently termed 2019-nCoV was officially announced as the causative agent by Chinese authorities on 7 January. 

What is real time RT-PCR
Real time Reverse Transcriptase Polymerase Chain reaction(real time RT–PCR) is a nuclear-derived method for detecting the presence of specific genetic material in any pathogen, including a virus. Originally, the method used radioactive isotope markers to detect targeted genetic materials, but subsequent refining has led to the replacement of isotopic labelling with special markers, most frequently fluorescent dyes. This technique allows scientists to see the results almost immediately while the process is still ongoing, whereas conventional RT–PCR only provides results at the end of the process.
Real time RT–PCR is one of the most widely used laboratory methods for detecting the COVID-19 virus. While many countries have used real time RT–PCR for diagnosing other diseases, such as Ebola virus and Zika virus, many need support in adapting this method for the COVID-19 virus, as well as in increasing their national testing capacities.
How real time RT PCR works in COVID-19 detection
The sample is collected by nasal pharyngeal swab or oral pharyngeal swab, for nasal pharyngeal  the swab is inserted in the nostril and gently moved forward in the nasal pharynx and then rotated for a specified period of time to collect secretion containing the virus. then the swab is placed immediately in the sterile tube containing the viral transport media.
Because corona virus contain extra ordinary single stranded RNA genome, to detect this virus with PCR, RNA molecule must be converted into complementary DNA by reverse transcriptase. the obtained DNA is then amplified by real time RT-PCR, The sample is treated with several chemical solutions that remove substances such as proteins and fats and that extract only the RNA present in the sample. This extracted RNA is a mix of the person’s own genetic material and, if present, the virus’s RNA.
The RNA is reverse transcribed to DNA using a specific enzyme. then additional short fragments of DNA that are complementary to specific parts of the transcribed viral DNA are added. If the virus is present in a sample, these fragments attach themselves to target sections of the viral DNA. Some of the added genetic fragments are used for building DNA strands during amplification, while the others are used for building the DNA and adding marker labels to the strands, which are then used to detect the virus.
The mixture is then placed in an RT–PCR machine. The machine cycles through temperatures that heat and cool the mixture to trigger specific chemical reactions that create new, identical copies of the target sections of viral DNA. The cycle is repeated over and over to continue copying the target sections of viral DNA. Each cycle doubles the previous number: two copies become four, four copies become eight, and so on. A standard real time RT–PCR set-up usually goes through 35 cycles, which means that, by the end of the process, around 35 billion new copies of the sections of viral DNA are created from each strand of the virus present in the sample.
As new copies of the viral DNA sections are built, the marker labels attach to the DNA strands and then release a fluorescent dye, which is measured by the machine’s computer and presented in real time on the screen. The computer tracks the amount of fluorescence in the sample after each cycle. When a certain level of fluorescence is surpassed, this confirms that the virus is present. Scientists also monitor how many cycles it takes to reach this level in order to estimate the severity of the infection: the fewer the cycles, the more severe the viral infection is.

Laboratory detection of COVID-19 using Real Time RT-PCR

The COVID-19 pandemic is far from getting contained but it appears other health threats are slowly creeping in. Over in Milipitas, some mosquitoes collected tested positive for the West Nile virus. Crews from the Santa Clara County Vector Control now plan to spray mosquito control treatment in select parts of the region as a preventive measure.
The West Nile virus was originally discovered in 2003. More than 7,000 locals in the area have contracted the virus with 309 dying from it. There are no symptoms caused by the virus but may cause fever, headache and body aches. In extreme cases, the virus can leave people with severe neurological damage or death in some cases.
Similar to the coronavirus, the people at risk of contracting the West Nile virus are the ones aged over 50. People who also have some underlying medical condition such as diabetes, high blood pressure, cancer and kidney-related disease are also at risk of contracting the disease.
Based on the latest reports, it appears that the virus is already spreading with Elk Grove and Illinois revealing mosquitoes also testing positive in their areas. Officials from the Sacramento-Yolo Mosquito Vector Control District confirmed that their sample was taken from an area near Bond Road and Highway 99. The rise in cases is attributed to the warm weather, the time where the number of mosquitoes increase, CBS Sacramento reported.
For bug bite first aid, here are 7 must-have products. Pixabay
"It's important for residents to take these findings seriously and do everything they can to protect themselves," Gary Goodman, district manager, said.
In Illinois, the Des Plaines Valley Mosquito Abatement District collected a positive mosquito batch last May 31 from River Forest. The North Shore Mosquito Abatement District also collected a positive mosquito batch on June 5 in Evanston, KWQC reported.
No human cases have been reported so far but everyone is urged to take the necessary protective measures. This includes wearing insect repellent at all times. Locals are also urged to report dead birds and neglected pools.

Califonia:west Nile virus found in milptus mosquitoes

Many people turn to 'Dr. Google' to self-diagnose their health symptoms and seek medical advice, but online symptom checkers are only accurate about a third of the time, according to new Edith Cowan University (ECU) research published in the Medical Journal of Australia today.
The study analysed 36 international mobile and web-based symptom checkers and found they produced the correct diagnosis as the first result just 36 per cent of the time, and within the top three results 52 per cent of the time.
The research also found that the advice provided on when and where to seek health care was accurate 49 per cent of the time.
It has been estimated that Google's health related searches amount to approximately 70,000 every minute. Close to 40 per cent of Australians look for online health information to self-treat.
Lead author and ECU Masters student Michella Hill said the findings should give people pause for thought.
"While it may be tempting to use these tools to find out what may be causing your symptoms, most of the time they are unreliable at best and can be dangerous at worst," she said.
Online symptom checkers ask users to list their symptoms before presenting possible diagnoses. Triage advice is about whether—or how quickly—the user should see a doctor or go to hospital.
The 'cyberchondria' effect
According to Ms Hill, online symptom checkers may be providing a false sense of security.
"We've all been guilty of being 'cyberchondriacs' and googling at the first sign of a niggle or headache," she said.
"But the reality is these websites and apps should be viewed very cautiously as they do not look at the whole picture—they don't know your medical history or other symptoms.
"For people who lack health knowledge, they may think the advice they're given is accurate or that their condition is not serious when it may be."
When to see a doctor
The research found that triage advice, that is when and where to seek healthcare, provided more accurate results than for diagnoses.
"We found the advice for seeking medical attention for emergency and urgent care cases was appropriate around 60 per cent of the time, but for non-emergencies that dropped to 30 to 40 per cent," Ms Hill said.
"Generally the triage advice erred on the side of caution, which in some ways is good but can lead to people going to an emergency department when they really don't need to."
A balance
According to Ms Hill, online symptom checkers can have a place in the modern health system.
"These sites are not a replacement for going to the doctor, but they can be useful in providing more information once you do have an official diagnosis," she said.
"We're also seeing symptom checkers being used to good effect with the current COVID-19 pandemic. For example, the UK's National Health Service is using these tools to monitor symptoms and potential 'hot spot' locations for this disease on a national basis."
Lack of quality control
Ms Hill points to the lack of government regulation and data assurance as being major issues behind the quality of online symptom checkers.
"There is no real transparency or validation around how these sites are acquiring their data," she said.
"We also found many of the international sites didn't include some illnesses that exist in Australia, such as Ross River fever and Hendra virus, and they don't list services relevant to Australia."
'The quality of diagnosis and triage advice provided by free online symptom checkers and apps in Australia' was published in the Medical Journal of Australia.
More information: Michella G Hill et al, The quality of diagnosis and triage advice provided by free online symptom checkers and apps in Australia, Medical Journal of Australia (2020). DOI: 10.5694/mja2.50600
Journal information: Medical Journal of Australia

Google's medical diagnosis and advices are "almost" always wrong: New study

 

An investigation of a major coronavirus outbreak aboard the USS Theodore Roosevelt aircraft carrier may reveal clues as to how Covid-19 affects younger adults.

 

This is the first major look at Covid-19 infections among healthy young adults that the CDC has released, More than 1,000 of the ship's nearly 4,900-member crew tested positive for Covid-19 following the outbreak. After spending weeks at a port in Guam, the ship returned to sea last month.
The majority -- nearly 60% -- of sailors in the study who had antibodies had neutralizing ones, "a promising indicator of at least short-term immunity.
Most reported mild or no symptoms, and those who took preventive measures -- such as face masks and social distancing -- were less likely to become infected.
What we saw was that most of the infections were actually mild, in addition to those that were asymptomatic, And this is perhaps different from studies of older Americans, or maybe even those who were hospitalized already, and certainly much different from those with underlying health conditions. With a number of young people reporting mild, atypical, or no symptoms from the virus, "symptom-based surveillance might not detect all infections.

 Most tested positive for antibodies

The report, published Tuesday, included a sample of 382 service members, with a median age of 30. According to the report, three-fourths were male. Nearly 60% of them tested positive for antibodies, and among them, 59% had also developed neutralizing antibodies by the time their blood samples were taken. Neutralizing antibodies bind to the virus, potentially disabling it from attacking human cells. In a handful of participants, these antibodies were detected more than 40 days after their symptoms began. However, because the data come from a single point in time, they note that longer studies will be needed to definitively show whether and how long these antibodies might protect against the virus.

 Lower infection rate in those who took protective measures

 

Those who took preventive measures were also less likely to become infected. Sailors who wore face coverings were less likely to become infected (55.8% versus 80.8%), as were those who avoided common areas (53.8% versus 67.5%) and practiced physical distancing (54.7% versus 70.0%). Symptoms more closely associated with Covid-19 in this sample were loss of taste or smell, muscle pain, fever and chills. Two were hospitalized among the 238 in the study confirmed to have been infected with the virus. Officials are working to "tailor our public health practices to the unique characteristics of this adversary whose secret weapon, as you know, is the ability to be transmitted by an individual before they know they're infected.

  Credit CNN.

 

Clues about Covid-19 among the young and healthy


The malaria disease burden remains a major impediment to economic development over many regions of sub-Saharan Africa. Large-scale insecticide treated net (ITN) distribution campaigns over the previous 15 years have reduced malaria cases by an estimated 40%. However, progress has plateaued; between 2014 and 2016 global incidence remained essentially the same. This a strong indication that current control measures are insufficient and additional novel strategies to control Anopheles mosquito populations or their capacity  to transmit Plasmodium parasites are needed if we are to make further inroads in reducing malaria incidence.
The outcome of vector–pathogen interactions can be influenced by symbiotic microbes. Notably, symbionts can prevent disease vectors from transmitting pathogens that are agents of human disease. This can be developed into a novel vector management strategy; symbionts are disseminated into vector populations to limit their capacity to transmit human disease.
In a research done, Scientists found that microsporidia MB, a fungi-like organism which occurs naturally in malaria-carrying mosquitoes, stops malaria transmission, but does not kill the mosquito. Researchers found this symbiotic microsporidia at moderate levels in wild Anopheles arabiensis mosquitoes in Kenya. When these mosquitoes were fed Plasmodium falciparum-infected blood, the microsporidia prevented the formation of oocysts in the mosquito. Sporozoites, the form of the parasite that are injected into humans during a blood meal, develop within oocysts. Disrupting oocyst formation, therefore, disrupts malaria transmission. The problem is that microsporidia MB is found in less than 10% of wild Anopheles arabiensis mosquitoes in Kenya, with greatest prevalence after peak rainfall. The aim now is to design ways to increase the presence and dissemination of this microsporidia so it can disrupt transmission.

Breakthrough: Microbe found to block malaria transmission