Human Health and Diseases

Clostridium botulinum is an obligate anaerobe i.e. it normally lives in the absence of oxygen. Facultative anaerobes are those who generally live in oxygen but may live without oxygen in suitable medium. Obligate aerobes can only live in the presence of oxygen while facultative aerobes generally live in oxygen but can also live without oxygen.

After infection, HIV starts to destroy the T-cells (T-helper lymphocytes). T. cells are very important for the immune system. In the early stage of infection, the decline in numbers of T.cells is observed.

The thymus is a major gland of our immune system. The thymus is responsible for production of T (thymus dervied) lymphocytes from immature lymphocytes, a type of white blood cells responsible for cell mediated immunity. Cell mediated immunity is extremely important for raising immune response against bacteria, yeast, fungi, parasites and virus. It is also critical in protecting against cancer, autoimmune disorders like rheumatoid arthritis, allergies etc.

Valium is a benzodiazephine (sedative) that gives a feeling of relaxation, calmness or drowsiness in the body. Morphine is the main opium alkaloid that depresses respiratory centre and contributes to the fall in blood pressure. Amphetamines are synthetic drugs and are stimulant in nature. Hashish is a hallucinogen.

Among the given options, the incorrect match with respect to the disease and the vector responsible for transmitting it is:

Option A: Anopheles culicifaciens – Leishmaniasis

Anopheles is actually a genus of mosquito known for transmitting malaria, not Leishmaniasis. The vector for Leishmaniasis is typically the sandfly from the genus Phlebotomus in the Old World or Lutzomyia in the New World.

Now let's look at the other options for correctness:

Option B: Glossina palpalis – Sleeping sickness

This is correctly matched. Glossina palpalis is a species of tsetse fly that is responsible for transmitting Trypanosoma brucei, the parasite that causes sleeping sickness, also known as African trypanosomiasis.

Option C: Culex pipiens – Filariasis

This is also correct. Culex pipiens, commonly known as the common house mosquito, is known to be a vector for the nematodes such as Wuchereria bancrofti and Brugia malayi, which cause lymphatic filariasis.

Option D: Aedes aegypti – Yellow fever

This is correct as well. Aedes aegypti is a mosquito that acts as the primary vector for yellow fever virus, as well as for other diseases like dengue fever, chikungunya, and Zika virus.

Therefore, the incorrect match here is indeed Option A, with Anopheles culicifaciens incorrectly matched to Leishmaniasis instead of malaria.

Short-lived immunity acquired from mothers to foetus across placenta or through mother’s milk to the infant is categorised as passive immunity. Passive immunity, an acquired immunity, is resistance based on antibodies performed in another host. In this case, the foetus is not directly responsible for its body immunity but it becomes immunised by mother’s milk across placenta.

Haemophilia B, a type of haemophilia is also known as christmas disease. It is due to deficiency of a blood coagulation factor, the christmas factor (factor IX). Christmas was the person (20th century) in whom the factor was first identified. Haemophilia B is a defect of the blood which prevents its clotting.

Carcinomas are malignant growths of the epithelial tissue that cover or line body organs.

The ability of radiations to kill cells is highest in the tissue with the highest number of dividing cells. Tumour cells proliferate rapidly. Hence, tumours are killed more rapidly by radiations.

Morphine is an opiate narcotic, Bhang is a hallucinogen, Reserpine derived form Rauwolfia, is used as tranquilizer, Cocaine is a stimulant.

Typhoid is caused by Salmonella typhi. The organisms of the disease are present in the stool. They may be present in urine. They can, therefore, be carried by water and contaminated food. Their spread through water can give rise to severe epidemics.
Polio is caused by Enterovirus. TB is caused by Mycobacterium tuberculosis. Tetanus is caused by Clostridium tetani.

Interferons are virus induced proteins produced by cells infected with virus.

Hallucinogens are drugs that change thoughts, feelings and perceptions of individuals. They cause hallucinations. LSD (Lysergic acid diethylamide) is one such hallucinogen that causes horrible dreams, chronic psychosis and severe damage to the central nervous system. Sedatives give a feeling of calmness, relaxation or drowsiness in the body. Their high doses induce sleep. Tranquillisers lower tension and anxiety without inducing sleep. Stimulants are the drugs that stimulate the nervous system, make a person more wakeful, alert and active; and cause excitement.

Asbestos fibres present in atmosphere due to industrial emission cause lung cancers (asbestosis).

The term "most infectious" can vary depending on the context and specific factors such as mode of transmission, reproductive rate (R0), and prevalence within a population. However, if we're talking about the ease with which these diseases can be transmitted from person to person, cough and cold, which can be caused by numerous viruses, notably the common cold being typically caused by the rhinovirus, is generally the most infectious out of the options provided.

Therefore:

• Option A: AIDS is caused by the human immunodeficiency virus (HIV) and is spread through certain body fluids from a person with HIV. It is a very serious and chronic condition, but it is less easily transmitted than cough and cold since it usually requires intimate contact or blood transfusion/needle sharing with an infected individual.
• Option B: Malaria is caused by Plasmodium parasites and spread by the bite of infected Anopheles mosquitoes. It is not directly contagious from person to person like a virus that causes a cough and cold.
• Option C: Hepatitis B is a liver infection caused by the hepatitis B virus (HBV). It is transmitted through exposure to infective blood, semen, and other body fluids, but is not as easily spread as a common cold.
• Option D: Cough and cold are generally caused by a variety of respiratory viruses. Because they are spread through the air (via coughing, sneezing) and personal contact, they are highly contagious and infect a large number of people easily.

In sum, while the other diseases listed are infectious and can be serious, a cough and cold (Option D) typically have the highest rate of transmission in everyday circumstances, making it the most infectious in terms of how easily it can be spread from person to person.

Syphilis is caused by a spirochete (spiral bacterium) Treponema pallidum. The symptoms of syphilis occur in three stages. The first stage usually consists of a painless lesion called a chancre at the organism’s site of entry. The second stage begins as the organism enters the blood. Symptoms such as fever, a flu like illness, a skin rash, hair loss, and swollen joints may come and go over a period of several years. In the third stage permanent brain damage, heart disease, and blindness often occurs. AIDS is a viral disease caused by Human Immuno deficiency virus. Gonorrhoea is a sexual disease and its causative organism is Neisseria gonorrhoea. Typhoid is caused by bacillus bacteria Salmonella typhi.

Cholera is an acute infection of the small intestine by the bacterium Vibrio cholerae, which causes severe vomiting and diarrhoea (known as ricewater stools) leading to dehydration. The disease is contracted from food or drinking water contaminated by faeces from a patient. The resulting dehydration and the imbalance in the concentration of body fluids can cause death within 24 hours. Since, a large quantity of fluid and salts are rapidly lost through stools and vomit, therefore, the most important treatment is to replace the lost fluid and salts equally rapidly. Rapid replacement of fluid and elecrolytes is needed by oral rehydration-therapy. The electrolytes consists of Na+ ions that prevents water loss from the body.

The common term for bovine spongiform encephalopathy is mad cow disease, which is a progressive neurological disorder of cattle. In humans it is called Creutzfeldt-Jakob disease, after the two doctors who first described the symptoms of the disease. It is caused by prions (proteinaceous infectious particles). It is characterized by rapidly progressive dementia associated with myoclonic jerks. The brains of affected individuals show a characteristic cystic degenerations.