Evolution of a pandemic: Coronaviruses to COVID-19

Coronavirus is not an exclusive finding of 2020 though it has been projected as “Novel Coronavirus” (nCoV). The so called nCoV has been designated as etiological agent of “Coronavirus Disease-2019” (COVID-19) that took shape of pandemic with its epicenter at Wuhan City of Hubei Province of China. Bovine and avian Coronaviruses are known since 1976 and a lot of research has already been done on their structure and pathogenicity.

The well characterized members of coronavirus family are positive-stranded RNA viruses. Coronaviruses possess a single-stranded, non-segmented, polyadenylated infectious RNA genome. The size of viral particles (virions) vary from 80-120 nm in diameter. Nanometer (nm) is ultra-small unit of measurement of length. There are one billion (1000,000,000) nanometers in a meter. These viruses could only be revealed through Transmission Electron Microscope (TEM) or Scanning Electron Microscope (SEM). Coronaviruses have pleomorphic look due to 10-20 nm long surface peplomers. Coronaviruses can cause diarrhea, hepatitis and bronchitis in lower mammals and birds. Three species of coronavirus are known to cause hepatitis in mice and seven species of coronavirus are known to cause bronchitis in birds.

Species of coronaviruses are characterized on the bases of molecular weight of surface polypeptides (glycoproteins). The molecular weight of surface glycoproteins of coronaviruses could be ranging from 15,000 to 200,000. They possess a large genome of 5x10⁶ to 8x10⁶ molecular weight. Massive research work has been done on coronaviruses in various virology laboratories all over the world to ascertain their genomic structure.

In the year 2002 “Severe Acute Respiratory Syndrome (SARS) was caused in humans by avian coronavirus (SARS-CoV). The animal reservoir of this coronavirus was perhaps bats. The avian coronavirus spread to other animals like cats and first infected humans in the Guangdong Province of southern China in 2002. An epidemic of SARS-CoV affected 26 countries in 2002-2003 and >8000 cases were reported as per World Health Organization (WHO). The transmission of SARS-CoV is primarily from human to human in the second week of disease due to excretion of viruses in respiratory secretions. So, infection spreads trough droplets of nasal secretion.

The current pandemic with Coronavirus has deliberately been given new nomenclature due to its genomic distinction from SARS-CoV known earlier. This new type of coronavirus causing SARS is called 2019-nCoV.

Symptoms of disease:

Symptoms of COVID-19 are like influenza and include fever, headache, shivering (rigors), myalgia, malaise, cough and sometimes diarrhea also. Fever is most frequently reported symptom, but it may be absent in initial stage especially in elderly and immunocompromised patients.

Cough may be dry initially with shortness of breath. Fever and diarrhea may progress in second week of disease. Elderly and people with associated illnesses like diabetes, hypertension, heart disease or organ transplant, may need special care to protect themselves from COVID-19.

Personal protection measures:

There is no immuno-prophylaxis for nCoV as vaccines are still under development. Personal hygiene, exercise and protein rich diet and vitamin-C are key to avoid coronavirus infection. Fresh fruits or juices rich in vitamin-C, high protein diet, coffee drinks, frequent drinking of warm water could be of great help to keep away COVID-19.

Frequent washing of hands with soap and water. Hand sanitization, wearing of face mask and maintaining physical distance (social distance) of approximately 6 feet would be of great help to avoid 2019-nCoV.

The need of the hour is not to panic but to follow the instructions and guidelines issued by local and national health authorities.

Diagnostic criterion:

Real Time - Reverse Transcription - Polymerase Chain Reaction (Real Time RT-PCR) is the only specific investigation to ascertain 2019-nCoV infection. The Chinese authorities isolated a new type of coronavirus from patients of outbreak of pneumonia in Wuhan City during laboratory investigations on 7^th January 2020 and named it 2019-nCoV.  Nasopharyngeal or oropharyngeal swabs are taken from suspected persons and transported to Laboratories in specially constituted transportation medium.

The principle of RT-PCR detection method is based on ‘Fluorogenic 5’ Nucleage Assay’. During the PCR reaction, the DNA polymerase cleaves the probe at 5’ end and separates the reporter dye from quencher dye only when the probe hybridizes to the target DNA. This cleavage results in the fluorescent signal generated by the cleaved reporter dye, which is monitored almost Real-Time by PCR detection system.

Warnings:

1.      This assay needs to be carried out by skilled personnel only.

2.      Clinical samples should be treated as highly infectious and samples should be prepared in biosafe laminar flow hoods.

3.      Do not use the kit after its expiry date.

4.      Carry out the test as per global standard procedure only.

5.      Avoid repeated freezing and thawing of reagents.

Care and treatment of infected persons:

Infected patients should be managed as per conditions. Patients should be home quarantined or admitted to COVID-19 Hospitals, as per clinical assessment. Symptomatic treatment should be started immediately.  Every patient needs to be instructed to wear face mask and wash/sanitize his/her hands frequently and maintain physical distance from other family members and friends. Proper counselling needs to be provided to patients with adequate supply of diet recommended by nutritionist. Health professionals need to wear ‘personal protection equipment’ (PPE) with adequate sanitization to avoid any cross infection.

Enforcement measures by administration:

Lockdown of public transport, schools, colleges, universities, offices and places of worships may be needed to restrict community transmission and spread of COVID-19. Medical infrastructure needs to be upgraded efficiently for optimum treatment of COVID-19 patients. Thermal screening at Airports, Seaports, Railway Stations and Bus Terminals is the first and foremost step to identify persons carrying virus. Proper arrangements for compulsory quarantine for 14 days of suspects with infection.

 

Investigations should be done as per WHO guidelines for pandemic surveillance. Containment Zones with large number of COVID-19 patients should be put under strict surveillance to avoid community spread of the disease. Strict enforcement of health & hygiene-related discipline could save the citizens and the nation.

Tuberculosis of Lymph Glands: A common type of surgical tuberculosis.

The tuberculosis in general comes under the domain of physicians, but several of its local manifestations are regarded as surgical tuberculosis. However, with powerful and effective anti-tuberculosis therapy majority of these cases can be treated without surgery. The tuberculosis of lymph glands is very common type of surgical tuberculosis. The lymph glands (filtering units of lymphatic system) commonly involved are those in the region of the neck; on one or both sides, above the clavicle. The affected lymph glands appear like a small or big lump with nodules. Initially the swollen lymph glands are painless, but later on the swelling may become soft due to breaking down of gland into a cheesy material and termed as 'cold abscess'.

Unlike an abscess or a boil due to acute infection, the glandular abscess is not 'warm' to touch. The abscess may break down, develop into a sinus and start discharging pus. The discharging sinus refuses to heal for a long time unless the patient is treated properly. It is worth remembering that every form of tuberculosis, in any part of the body leads to signs and symptoms of 'tubercular toxemia'. The 'tubercular toxemia' causes evening rise of temperature, weight loss, loss of appetite (anorexia), general weakness and sweating of body at night. The consultation of physician is must for early diagnosis and treatment of tuberculosis of lymph glands if above mentioned symptoms are there.

Potato & Mushroom Poisoning

If you study the botanical origin of potato, you would find that it belongs to the group of plants, the stems and leaves of which contain toxic agents termed as solanines. The botanical name of potato is Solanum tuberosum and it belongs to the family Solanaceae. Solanines are known to cause poisoning in cattle eating the potato plant. The tuber (potato) itself also contains small amounts of poisonous material called solanines in its peels. You must have seen that storage of potatoes leads to greening and sprouting. Both these processes lead to the production of poisonous material around the 'sprouting eyes' and also inside the flesh of potatoes. Sprouting and green potatoes taste bitter due to the presence of solanines and should not be consumed. Sometimes, people who are unaware of the poisonous nature of green and sprouting potatoes; eat these and develop poisoning symptoms. The onset of potato poisoning symptoms occurs some 4 to 12 hours after its consumption. The abdominal pain, vomiting and diarrhoea are predominant symptoms of potato poisoning. Mild headache and fever have also been reported in some cases. Severe potato poisoning may also lead to a state of coma.

Be cautious while eating potato products. The treatment of potato poisoning is always symptomatic; loss of fluids and electrolytes have to be replaced orally with oral rehydration powder dissolved in water or intravenously in cases of severe dehydration. Use of antibiotics should be avoided in known cases of potato poisoning. An average general practitioner may miss the diagnosis of potato poisoning and pass of the case as a common case of 'gastroenteritis'. The potato poisoning may be severe form of food poisoning in students eating midday meal from the common kitchen at schools, as the kitchen staff generally overlook the quality of potatoes received by them.

Mushroom poisoning is also presented with abdominal pain, vomiting and profuse diarrhoea after latent phase of around 12 hours or more. Severe mushroom poisoning may also lead to liver and kidney failure within 3 to 4 days after the development of vomiting and diarrhoea. Some of the mushrooms, e.g. Amanita phalloides are so poisonous that consumption of one mushroom is sufficient to cause severe poisoning and three mushrooms could be considered a fetal dose. With the cultivation of mushrooms being taken up by the trained personals, the cases of mushroom poisoning have come down. Only those who collect and eat wild mushrooms fall prey to mushroom poisoning due to lack of knowledge about the identifying features of poisonous mushrooms. Knowledge is the key to care and maintenance of health. Never eat green or sprouting potatoes and wild mushrooms to save yourselves from potato poisoning or mushroom poisoning.

Rabies: Signs and Symptoms in Animals and Human Beings

Rabies is a disease, which man acquires from vertebrate animals. The disease is caused by a virus infecting the nervous tissue. Rabies causes 100% mortality if the human beings bitten by rabid animal and are not adequately vaccinated. Rabies is a disease of antiquity, having been known to mankind probably earlier than 2000 BC. Clinically, in both animals and man, rabies can manifest either in the form of hyperactivity (furious rabies) or paralysis (paralytic or dumb rabies). Human beings if not given prophylactic vaccination after animal bite always develop furious type rabies, whereas around 25% of dogs develop furious type rabies. Excessive salivation and lacrimation may also be present in affected animals and human beings. Hydrophobia (fear from water) may also be present in majority of the cases. No drugs work after the development of symptoms of rabies and patients lapse into coma and die. Millions of people are treated worldwide with post bite prophylactic vaccination for suspected rabid dog bites, every year.

The great Louis Pasteur was the first authority to make rabies vaccine by inactivating rabies virus obtained from the spinal cord of infected rabbit. The 'old stock vaccine' is made from the monkey's nervous tissue and 12 to 14 injections of this vaccine are required for 100% protection. Almost half of people vaccinated with 'old stock vaccine' may have appreciable local side effects and only 5 in 10,000 may have serious side effects. The latest anti-rabies vaccines have minimal side effects. The Purified Chick Embryo Cell (PCEC) and Human Diploid Cell (HDC) vaccines give 100% protection not only to those who are bitten by rabid dogs but also to those who work with rabies virus and handle reservoir animals. All vaccines are easily available worldwide at reasonable rates. Neurological complications may develop in persons vaccinated with 'old stock vaccine'.

Incubation Period: The incubation period of rabies disease is usually between one and two months. In extreme cases incubation period may be a few days or rarely, even years. The site of the bite is indicative in determining the length of incubation period. Infants and children have a shorter incubation period than adults. Restlessness, agitation, excitation, confusion, muscle spasms, hallucinations, thought disorders and hydrophobia are common signs of possibility of development of rabies in person infected with rabies virus.

Diagnosis: The diagnosis of rabies in animals is made by microscopic examination of stained brain smears or histological sections for Negri bodies. The biological test for rabies is intra-cerebral inoculation of mice with the nervous tissue squash of animals or body secretions of infected human beings and isolation of virus from inoculated mice after an incubation period of 1-2 weeks. In human beings the rabies virus can directly be isolated from saliva, urine and cerebrospinal fluid, and revealed by electron microscopic study.

Celiac Disease: Gluten-free diet is the treatment

The term allergy means hyper-action of our body's immune system to allergens (mostly proteins or compounds tagged to proteins). Like our skin and respiratory tract, our digestive tract (intestines) can also be hypersensitive to some constituents of food. Celiac disease is a disorder of the digestive system which is caused by intolerance/allergy to a protein called gluten. People with celiac disease can not tolerate gluten. The disease is partially genetic and inherited. Parents, siblings and children of people with celiac disease may also have/be having this disease. Celiac disease damages the inner lining of the small intestine and interferes with the absorption of nutrients from food. The cause of celiac disease is the immunological allergic reaction to gluten present in food that causes inflammation and damages the inner border (microvilli) of small intestine. Figure-1 below shows the ultrastructural changes at the inner lining of small intestine in a patient affected by Celiac disease. A visual comparison with Figure-2 (Normal inner surface of small intestine) would make you understand the pathological change.

Figure-1: Electron micrograph of biopsy from the small intestine of a patient affected by celiac disease showing eroded microvilli.

Figure-2: Electron micrograph showing normal microvilli at the inner surface of small intestine.

Sources of Gluten

Wheat, barley and rye are the main source of gluten. The gliaden component of gluten causes celiac disease. Some adhesives, medicines and vitamin products, which we use daily, may contain gluten.

Diagnostic symptoms of celiac disease

Some of the typical symptoms of celiac disease are failure to gain weight, diarrhoea, irritability, vomiting, abdominal pain and foul stools, early in infant life. The most common period of presentation and detection of celiac disease is between six months and two years of age. Some children may present with excessive appetite, abdominal distension, wasted muscle, finger clubbing and edema.

Preventive treatment of celiac disease

A gluten-free diet is the only treatment of celiac disease. A person aware of having intolerance to gluten should avoid eating foods containing wheat, barley and rye products. Modern drugs may provide symptomatic relief but ultimate treatment is preventive therapy in celiac disease.

Important Tips

1. Parents of the children with celiac disease have great responsibility to make the children comply with the doctor's instructions for gluten-free diet.


2. Recognizing and avoiding new food products containing wheat, barley or rye is a great challenge and people with celiac disease should be very careful since non-compliance of gluten-free diet may cause relapse.


3. People having celiac disease should take food items prepared from rice and corn only along with fruits, juices and milk products.


4. Reading the contents of grocery items is important before eating because many corn and rice products come from the manufacturers of wheat products.


5. Gluten-free but balanced diet is must for normal growth of the children affected by celiac disease.


6. Medicines coated/laced with gluten products should be avoided.

Arthritis is Curable irrespective of Causes

There is nothing to panic with a diagnosis of arthritis. If diagnosed in first two years, arthritis can be treated completely and one can lead a perfectly normal life. However, dietary restrictions are must for those suffering from gouty arthritis. There are a variety of forms of arthritis and it can affect anybody at any age. There are two major forms of arthritis: (1)Inflammatory: Which causes inflammation of joints and may effect any person at any age. Rheumatoid arthritis, psoriatic arthritis, lupus arthritis and gouty arthritis fall in this category.(2) Non-inflammatory: Age related degenerative changes causing stiffening of joints are termed as non-inflammatory arthritis. Osteoarthritis falls under this category. Most of the inflammatory forms of arthritis, especially rheumatoid, psoriatic and gouty arthritis are becoming increasingly common in the age group of 20 to 45. Gouty arthritis is caused by increased level of uric acid in blood, is more common in men than women. Regular intake of alcohol, red meat and high protein diet could be the cause of high incidence of gouty arthritis in young men than women. In women, gouty arthritis could be diagnosed during
postmenopausal age.

Symptoms of Arthritis: Swelling with stiffness, pain and redness of joints could be associated with arthritis. In the beginning ankles, wrists or small joints of fingers could be involved. Lupus arthritis represents with fever, skin rash, skin lesions and hair loss, and is more common among women. Skin lesions are also associated with psoriatic arthritis.

Important Note: Accurate diagnosis is a key to the management and cure of arthritis. Disease itself may have more adverse effects on our health than the drugs. Patients should continue the treatment without caring for the side effects of drugs if the treatment is effective and one feels normal.

Salads may cause Neurocysticercosis

It is well known that infestation with tapeworm in pork-eaters may cause neurocysticercosis when the infection reaches the brain through the blood. In India majority of vegetarians or salad-eaters and non pork-eaters have also been showing the disease. Neurocysticercosis have been found to be more prevalent in salad-eater children as compared to adults. Vegetables like cabbage, carrot, beat and radish, eaten raw could lead to cysticercosis. Farm workers should be educated to wash the vegetables in clean water before marketing or consuming. Contaminated water used for irrigation and washing the vegetable before marketing is the major cause of increasing incidence of neurocysticercosis in the rural and urban population in developing countries. Vegetarians and those who do not eat pork are equally at risk due to their salad eating habit. There is a need to develop healthy eating habit and to avoid eating salads prepared at restaurants and fast food outlets as majority of them avoid properly washing the vegetables during preparation of salads. Be conscious about hygiene.

Symptoms of neurocysticercosis are: Intense headache and seizures if the tapeworm travels to the brain. After the eggs are hatched in the intestine, the worms travel through blood stream to different organs like, brain, heart, eyes and even the spinal chord. In muscles, cysts cause nodules under the skin. Cysts in eyes can impair vision and the lesions caused by tapeworm in heart may lead to cardiac arrhythmias or heart failure.