WUHAN, CHINA – JANUARY 22: (CHINA OUT) A women wears a mask while walking in the street on January … [+]
As of this writing, the coronavirus, or COVID-19, has spread to 28 countries, with over 76,000 infected. These numbers will only continue to grow, as the threat of a global pandemic is now upon us.
According to this week’s China CDC Weekly report, a total of 1,023 deaths have occurred in confirmed cases of COVID-19 infections in China alone. This presents a case-based death rate of 2.3%, as only 44,672 cases of a viral syndrome with pneumonia were found to be due to COVID-19, as opposed to other causes of pneumonia-related deaths. As China, more specifically Wuhan in the Hubei Province, has seen the highest number of infections to date worldwide, the epidemiology of these infections has been more robust to analyze. And while anybody, anywhere, on land or at sea, can contract this infection, the degree of symptoms and risk of mortality varies widely based on several demographic factors:
- Older individuals fare more poorly: Of the 1,408 cases of COVID-19 in patients over age 80, there have been 208 deaths, for a case fatality rate (number of deaths per number of cases) of almost 15%. By contrast, there have been no deaths in the 416 cases in children ages 0-9 years, and one death among the 549 cases of children and adolescents ages 10-19 years.
- Those with other chronic illnesses do worse: There have been approximately 5,000 cases where individuals have reported a known co-morbid medical condition, such as high blood pressure, diabetes, heart disease, chronic lung disease, or cancer. The average mortality rate in these groups is in the 5-10% range, whereas of the 15,000 individuals who reported no other medical conditions, the mortality rate to date has been less than 1%.
- You’re better off getting it this month than last month. Those who became ill before January 10, 2020 had an up to 15% mortality, whereas those who became ill after February 1, 2020 have had less than 1% mortality. This is likely due to extremely heightened awareness of potential for infection, with resultant earlier recognition and earlier interventions.
- Females fare better than males. Much better. According to a New York Times piece this week, despite the fact that men and women have been roughly equally infected (51.4% infected are males), the death rates differ substantially: 2.8% death rate in males, and 1.7% death rate in females.
Joyful beautiful young woman in superhero costume posing on sunset background.
This was found to be the case across all age groups. Looking back on data from SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome), which were both also pathogenic coronaviruses, males had higher mortality rates than females. Mice experiments where mice were infected with SARS and MERS demonstrated that male mice were more susceptible to infection than female mice, and that removing ovaries or blocking estrogen in female mice made them more susceptible to infection and infection-related mortality. One concept which continues to be investigated in this current outbreak is the protective nature of estrogen in such infections. In addition to estrogen, the presence of two X-chromosomes, which carry genes for immunity, may play a part in the biologic difference between females (who carry two X-chromosomes) and males (who carry one X-chromosome) when it comes to immunologic response to infections.
From an environmental standpoint, chronic lung disease due to cigarette smoking likely plays a part in disease-related morbidity and mortality, especially when it comes to infections such as SARS, MERS, and COVID-19. One third of the world’s smokers live in China. More than half of Chinese men smoke, whereas only about 2% of Chinese women smoke. From a societal health standpoint, women tend to seek out health care more readily than men, making them more likely to be evaluated and treated early in a given disease process. In addition, while hand washing does not fully prevent the spread of any disease, it certainly can reduce the risk of widespread contagion. That is, if soap is part of the hand washing equation. Some data have shown that men are much less likely to wash their hands with soap than are women. Remember that the next time a man walks out of a restroom to shake your hand.
Young chinese man smoking
The flip side of the robust immune systems of females explains why women are substantially more susceptible to autoimmune diseases such as lupus, rheumatoid arthritis, and certain types of thyroid disease. In autoimmune disease, one’s own antibodies ‘attack’ certain cells, leading to inflammatory responses and chronic disease in one or multiple organs. Women are more than three times as likely as men to develop an autoimmune disease.
Woman touching knee, sitting on bench, pain in joints, problems with knees
While the COVID-19 epidemic, soon to be pandemic, has yet to show consistent signs of slowing, in fact, quite the contrary, getting a better sense of the importance of early recognition and intervention, especially in older males, may help health officials gain some control of its progression. If not today, then hopefully soon.