Category: Research

Fogging- A Powerful Disinfecting Layer for Biohygiene ?

By: Nelly Nastase


Fogging- A Powerful Disinfecting Layer for Biohygiene?Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), most likely spreads through invisible respiratory droplets created when an infected person coughs or sneezes. Those droplets can be inhaled by nearby people or land on surfaces that others might touch, spreading the infection when they touch their eyes, nose, or mouth (Science, 2020).

There is a lot that is not fully known about the new SARS-CoV-2 virus, like how long does it remain active in the air or on surfaces. According to a recent study, the virus remains in the air for up to 3 hours and approximately 2-3 days on stainless steel and plastic surfaces (Van Doremalen et al, 2020). Another study found that a related SARS-CoV-1 virus that causes SARS can persist up to 9 days on non-porous surfaces such as plastic or stainless steel (Kampf et al, 2020).

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Several reports found that the SARS-CoV-2 virus has been detected in feces, indicating that the virus can spread by people who don’t properly wash their hands after using the bathroom (Wang et al, 2020). However, the CDC says there is no indication that it spreads through drinking water, swimming pools, or hot tubs (CDC, 2020a). The virus has been found to spread less effectively outdoors due to a variety of factors.

Previous research on the relationship between respiratory-borne infectious diseases and temperature have indicated that the ability of SARS and influenza viruses to spread decreased with increasing temperature (Jaakkola et al, 2014; Chan et al, 2011). The underlying hypothesis includes higher vitamin D levels, resulting in better immune responses (Aranow, 2011); increased UV radiation; and school holidays in the summer. Reports of correlation between respiratory diseases and the levels of UV radiation have also been considered, and previous studies have reported that high levels of UV exposure can reduce the spread of SARS-CoV virus (Duan et al,

However, according to the current results, the cumulative incidence rate and R0 of COVID-19 holds no significant association with ambient temperature, suggesting that ambient temperature has no significant impact on the transmission of SARS-CoV-2 (Yao et al, 2020). This is similar to the Middle East respiratory syndrome (MERS) epidemic, where the MERS coronavirus continued to spread even at temperatures of around 45°C (Alshukairi et al, 2018).

Measures to minimize airborne transmission of COVID-19 indoors include sufficient and effective ventilation, possibly enhanced by particle filtration and air disinfection, avoiding air recirculation, and avoiding overcrowding (Morawska et al, 2020).

Fogging is a deep cleaning method that has been used in hospitals for dealing with MRSA. Fogging uses an antiviral disinfectant solution to clean and sanitize large areas of a building quickly and effectively by spraying a fine mist from a spray gun, which is then left to evaporate, usually for less than an hour. It can kill off viruses and other biological agents in the air and on surfaces. The task requires full protection from the sprayed chemicals. The product used is safe on electronics and other equipment as the mist is exceptionally fine to penetrate all areas to kill off the virus effectively.

Fogging should be conducted only using products whose product label specifically includes disinfection directions for fogging, fumigation, or wide-area spraying. It means that the product’s safety and efficacy have been evaluated by the EPA, specifically for fogging. Otherwise, the product might not be effective in disinfecting surfaces by fogging (, 2020a). The EPA has been expediting applications to add directions for use with electrostatic sprayers to products intended to kill SARS-CoV-2 (, 2020b).

Wet or chemical fogging employs a fine mist of disinfectant solution which remains on surfaces for several hours until it evaporates. Dry fogging, on the other hand, uses smoke to treat the area, leaving no chemical trace behind. The main advantages of fogging are the ability to cover large areas quickly and effectively; the ability to reach areas difficult to clean using other techniques. It eliminates pathogens in the air and on all surfaces, including furniture, walls, and ceilings.

The downsides are that it requires a thorough cleaning in advance as dirt and other materials might cover parts of a surface, protecting it from the effects of the biocide spread by fogging; the chemicals used are often more expensive than other disinfectants, and the required amount depends on the size of the space that is being disinfected. However, fogging is cost-effective because it allows the rapid disinfection of large areas with minimal disruption.

Ultraviolet (UV) radiation can be used for non-contact disinfection, where UV-C light is used to kill or inactivate pathogens by damaging their DNA or destroying nucleic acids. UV disinfection is commonly used to treat water – its advantages are lack of chemical agent, ease of use, and low economic cost. The lack of chemical agent means that UV disinfection can be used as often as needed, without any fear of long-term consequences for the operator or the client.

However, UV disinfection requires a direct impact of UV radiation for some time – if the light shines indirectly, or is obscured by dirt or something else, the disinfecting effect is lost. Also, prolonged exposure to UV light can be harmful to humans – skin exposure can produce sunburn and skin cancer. In addition, eye exposure can damage the cornea or, in rare cases, the retina, leading to temporary or permanent vision impairment or even blindness. The risk is compounded by the fact that UV light is invisible to the human eye. Therefore, the operation of UV disinfection equipment requires caution.

Rehydration Solutions: Use During COVID-19 Pandemic

By: James Mayo & Blanca Lizaola-Mayo MD


Water is a critical nutrient. All known life forms depend on water; it is considered as one of the best solvents for inorganic matter because it exhibits the highest known polarity. Besides, it also exhibits extremely high heat capacity, making it a superior heat regulator. In the human body, water’s role as a solvent – where it dissolves ionic compounds to create solutions that allow transport of metal ions across molecular membranes – is the one with the most significant consequences for our health and well-being.

During day-to-day activities, a person typically loses about two liters of water through breathing, sweat, urine, and bowel movements. This is increased significantly during exercise when fluid loss can be up to two liters per hour. In addition to water, sweat contains different metal ions: mostly sodium (range 10-70 mEq/L) and chloride (range 5-60 mEq/L) (Baker, 2015). During the COVID19 pandemic, hydration is imperative for well-being. In addition, staying active is critical for both physical and mental health. Physical activity helps our mind and body in many ways (VicHealth, 2020;, 2020). But it is essential to be careful as increased physical activity can lead to dehydration if one is not adequately prepared.

Downloadable Report → Rehydration Solutions: Use During COVID-19 Pandemic

Physical exertion places a strain on our immune system. At a higher level of physical exertion, our immune system undergoes significant changes: an increase in stress hormones and cytokine concentrations, changes in body temperature, an increase in blood flow, and dehydration (Nieman, 2007). These changes create a window of 3 to 72 hours when the immune system is impaired, potentially allowing pathogens to gain a foothold in the human body. Fluid replacement is the most effective countermeasure against exertion-related immune perturbations. In addition, a study of thermal dehydration has shown that the changes to hematologic parameters during thermal exposure without exercise are remarkably similar to those during physical exercise (Ohira et al., 1981). Dehydration has the same effect on the human body, regardless of the level of physical activity, and it should always be treated with caution.

Many essential workers have had a significant increase in their workload during the pandemic. The use of personal protective equipment requires more exertion to complete any task, and its relative scarcity during the pandemic means that people spend more time using it than they usually  would. COVID-19 patients commonly exhibit fever, diarrhea, and vomiting as symptoms of the disease. If left unattended, it can lead to severe dehydration, exacerbating their symptoms and making their recovery more difficult.

The issue of dehydration is much more common and dangerous, especially when considering the risks that front line medical workers are facing. Therefore, the proper use of rehydration tools, while seemingly small, can make a big difference: it can help front line medical workers, and their patients fight the disease and help everyone else stay healthy during these challenging times.

Oral rehydration solutions (ORS) are specialized formulations, usually in the form of a powder which contains a mixture of essential salts and sugar that are dissolved in water to create a drink that facilitates faster absorption of water in the human body. Their efficacy is based on the ability of sugar to stimulate sodium and fluid absorption in the small intestine via a cyclic AMPindependent process (Binder et al., 2014). The addition of zinc was found to significantly reduce the duration and severity of diarrheal episodes and the likelihood of subsequent infections for 2-3 months (Khan et al., 2011).

ORS was developed in the 1970s to treat severe dehydration resulting from severe diarrhea without the logistical needs of intravenous hydration using sterile solutions. There have been several significant modifications to ORS since, to improve its efficacy and effectiveness. Original formulations were iso-osmolar: they had the same osmolarity of 311 mOsm/kg H2O as the fluid in the human cells. However, several studies have shown that hypo-osmolar food-based formulations performed better in clinical trials (Gore et al., 1992). It was subsequently determined that hypo-osmolar glucose-based formulations also have superior performance and that this was due to lower osmolarity of these formulations (Duggan et al., 2004). Since then, reduced osmolarity formulations have been adopted by many countries as the standard ORS formulations (Walker et al., 2009).

While ORS has been well established for treating dehydration caused by diarrhea, especially in children, it has not been widely adopted to treat dehydration caused by other medical conditions. Even though ORS is not a drug, it is inexpensive and is ideal for common usage to treat conditions  before drugs are employed. One of the reasons may be that ORS does not alleviate the symptoms of the underlying illness: reduce diarrhea, for instance, but corrects acute dehydration. There is a lack of awareness about the existence of ORS and its ability to prevent dehydration in a variety of conditions. ORS may be used as a preventive tool to avoid dehydration.

Passive Immunity

The Next Generation of Pandemic Response

By Ravi Starzl

Passive Immunity The Next Generation of Pandemic ResponseImmunization is a process of fortifying an individual’s immune system against an agent, typically disease-causing pathogen or a toxin. When the immune system is exposed to foreign molecules, this will trigger an immune response. Because of immunological memory, our immune system is also able to develop the ability to respond quickly to any subsequent encounter with the same agent, which is a function of the adaptive immune system – a subsystem which responds within 4-7 days to a previously encountered foreign molecule. The concept of exposing the body to a foreign agent in a controlled manner to artificially activate the immune system and impart the ability of a quick response to a subsequent encounter due to immunological memory is called active immunization.

Downloadable Report → Passive Immunity

Active immunization gives the body the ability to produce antibodies to counter the pathogen or a toxin on its own. The most common technique of active immunization is vaccination, a process of introducing a microorganism or a virus in a weakened, live or killed state, or proteins or toxins from that microorganism, triggering the body’s adaptive immunity. This allows the body to quickly respond to a next encounter with the same pathogen or toxin. Inoculation refers to a method where the body is exposed to a milder form of a disease to induce immunity. It originated as a method of preventing smallpox, where dried smallpox macules were used to induce a generally milder form of the disease, which still induced full immunity to the disease. Compared to vaccination, it is inferior due to significantly higher risk – vaccination does not cause disease, even in its milder form, while inoculation does.

Passive immunization is a process of introducing antibodies into the body directly, rather than imparting on the body the ability to produce them. This still imparts immunity, however, because this immunity is not caused by the body’s immune system, it will only last as long as the introduced antibodies as present in the organism. This is called transient immunity. Antibodies have been used for the prevention and treatment of various diseases for centuries (Keller, 2000). Immunization by the administration of antibodies is a very efficient way of obtaining immediate, short-lived protection against infection or the disease-causing effects of toxins from microbial pathogens or other sources.

Due to its rapid action, passive immunization is often used to treat diseases caused by infection or toxin exposure. In bacterial diseases, antibodies neutralize toxins, facilitate opsonization, and, with complement, promote bacteriolysis. In viral diseases, antibodies block viral entry into uninfected cells, promote antibody-directed cell-mediated cytotoxicity by natural killer cells, and neutralize virus alone or with the participation of a complement. Prior to the discovery of antibiotics, antibodies were the only available treatment for a significant number of infectious diseases. They can be administered as:

  • human or animal plasma or serum
  • pooled human immunoglobulin for intravenous (IVIG) or intramuscular (IG) use
  • high-titer human IVIG or IG from immunized or convalescing donors
  • monoclonal antibodies (MAb).

Passive immunization occurs widely in nature to protect offspring against disease at birth and during lactation in mammals, through the transfer of immunoglobulins from mother to its offspring. This can be dated back hundreds of millions of years, to the primitive species of fish. In humans, the half-life of immunoglobulins (IgG) is about 3 weeks, making the maternal antibodies active in children 2-3 months old (Shahid, 2002). In birds (IgY) and fish (IgM), immunoglobulins have a shorter half-life of only a few days (Hedegaard, 2016). Passive immunization is not a real alternative to vaccination, as it does not confer long-term immunity. However, vaccines are not a viable option for immuno-compromised people, whose immune system is too weak to respond to an infection with its antibodies. Passive immunization provides immunity regardless of the body’s own response to infection, making it a viable option for these cases, too.

Due to the long-lasting immunization effects, vaccination is considered the superior method of imparting immunity. There are currently 27 diseases for which vaccines are available (World Health Organization, 2011). However, vaccination is only available for known diseases or known strains of viruses, and developing a new vaccine is a long and expensive process (Struck, 1996). As a consequence, many infectious diseases that have emerged over the past few decades have seen little or no vaccine development, due to a relatively small number of infections and perceived lack of commercial market for such products (Hixenbaugh, 2020). Long development and testing processes make vaccines eminently unsuitable as a rapid response tool for emerging diseases.

Even when a disease represents a mutated form of a known pathogen, there is no guarantee that the vaccine for the original pathogen would be fully effective, and in most cases, it is not (like with different influenza strains). This is particularly pertinent in today’s globalized world, where epidemics have a greater potential to spread worldwide than ever before. Therefore, while vaccines represent our best defense against infectious diseases, there is still a need for a “firebreak” – a set of measures designed to delay the spread of a disease long enough to allow for vaccine development. This report is meant to offer an introduction to the concept and strategy of passive immunity as a mechanism of rapid pandemic response and a broad overview of the current state of technology.