Dengue

Dengue and dengue hemorrhagic fever

Definition    Dengue hemorrhagic fever is a severe, potentially fatal infection that occurs when someone with immunity to one type of Dengue virus is infected by a different type. It is spread by certain mosquitoes (Aedes aegypti) which bite primarily during the day.

Alternative names   Hemorrhagic dengue; Dengue shock syndrome; Philippine hemorrhagic fever; Thai hemorrhagic fever; Singapore hemorrhagic fever

Over the past 3 decades there has been a dramatic global increased in the frequency of DF, DHF, & DSS and their epidemics, with a concomitant increase in disease incidence.

Dengue is a mosquito-borne infection which in recent years has become a major international public health concern. Dengue is found in tropical and sub-tropical regions around the world, predominantly in urban and semi-urban areas.

Dengue hemorrhagic fever (DHF), a potentially lethal complication, was first recognized in the 1950s during the dengue epidemics in the Philippines and Thailand, but today DHF affects most Asian countries and has become a leading cause of hospitalization and death among children in several of them.

There are four distinct, but closely related, viruses that cause dengue. Recovery from infection by one provides lifelong immunity against that serotype but confers only partial and transient protection against subsequent infection by the other three. There is good evidence that sequential infection increases the risk of more serious disease resulting in DHF.

NUTRITION

NUTRITION

Good nutrition has a direct impact on your overall health and quality of life. When you follow a healthy diet that consists of fruits, vegetables and whole grains, you aren’t just satisfying your hunger—you’re nourishing your body too.  Although it’s okay to indulge once in a while (we’ve all been there!), it’s crucial to keep track of what you eat so you can maintain a healthy lifestyle. Our bodies are built of and powered by solely what we eat and drink. Food is the source of all of the energy needed why do humans have to eat? Is it just because we get hungry? That is not all. People get energy from food. We need energy all the time, when we run, jump, sing, and even when we sleep. We create all the energy we need by eating. The structures components that make up the human body, such as muscles, organs, and bones, are also composed of the nutrients contained in food, meaning that it is. This is why eating and taking in the nutrients that provide energy and become the components of our bodily structures is essential to for sustaining human life.

 

 

IMPORTANCE OF NUTRITION

1.    DECREASES THE CHANCE OF DEVELOPING VARIOUS DISEASES

Having quality eating habits can reduce your risk of developing certain diseases that could severely impact your health. Among these maladies are hypertension, diabetes and heart disease, which was the leading cause of death in the United States in 2014, according to the Centers for Disease Control and Prevention. If you want to increase your chances of staying well, it’s best to stick to a healthy diet.

2.    HELPS KEEP A HEALTHY WEIGHT

Eating natural food instead of processed foods can have a positive effect on your weight. Plus, your weight also influences your overall health. For example, being overweight raises your risk of developing Type II diabetes. It can also harm your joints, limiting your mobility.

 

3.    INCREASES ENERGY LEVELS

Have you ever eaten a bunch of junk food and experienced a sudden jolt of energy, only to feel completely exhausted a short time later? That is how your body reacts when you absorb an abundant amount of refined sugar. By avoiding such unhealthy foods and fueling your body with nutritious options instead, you’ll be able to increase your energy levels throughout the entire day, not just for an hour or so—and you won’t endure that crash-and-burn effect. You’ll be able to focus on what’s going on around you rather than on how tired you feel. So, put down that candy bar and pick up a piece of fruit that contains natural sugars!

 

4.    IMPROVES SKIN HEALTH

Good nutrition doesn’t just affect your weight or your energy. It can also play a role in the health of your skin. According to the American Academy of Dermatology,  foods that contain vitamins C and E, lycopene and other antioxidants, as well as olive oil, can help to protect your skin against sun damage.

 

5.    BOOSTS IMMUNE SYSTEM

When you practice good nutrition, you’re consuming natural and healthy foods that can help your body. This includes improving your immune system. 

Classification of food

Classification of food

There are many ways of classifying foods

1. Classification by origin

                     1)    Foods of animal origin

2)  Foods of vegetable origin. 

2. Classification by chemical composition

             1) Proteins

2) Fats

3) Carbohydrates

4) Vitamins

5) Minerals.

3. Classification by predominant function

1) Body-building foods, e.g., milk, meat, poultry, fish, eggs, pulses, groundnuts, etc.

2) Energy-giving foods, e.g., cereals, sugars, roots and tubers, fats and oils.

3) Protective foods, e.g., vegetables, fruits, milk.

 

4. Classification by nutritive value

1)      Cereals and millets

2)      Pulses (legumes)

3)      Vegetables

4)      Nuts and oilseeds

5)      Fruits

6)      Animal foods

7)      Fats and oils

8)      Sugar

9)      Condiments and spices

10)  Miscellaneous foods.

 

 

 

Carbohydrates

•      Carbohydrates are the sugars and starches found in foods.

•      They are made up of carbon, hydrogen, and oxygen.

•      Athletes are not the only people who need carbohydrates.

•      Everyone needs them.

•      There are two general types of carbohydrates: simple and complex.

The Role of Carbohydrates

·         our body converts all carbohydrates to glucose.

·         Glucose that is not used right away is stored as glycogen.

·         When more energy is needed, our body converts the glycogen back to glucose.

·         our body converts and stores the excess carbohydrates as body fat.

Fats (Lipids)

•      Fats are solid at 20 deg. C; they are called "oils" if they are liquid at that temperature.

•      Fats are the nutrients that contains the most concentrated form of energy. Fats are type of lipid.

•      Lipids are substances that are somewhat similar to carbohydrates, but they contain less oxygen and they do not dissolve in water.

•      Fats are part of many body tissues and are important as carriers of other nutrients, such as vitamins.

•      Fats also carry the flavor of foods – making foods tastier, but consumption of fat should be closely monitored.

The Role of Fats

·         They transport vitamins A, D, and K in the blood.

·         They serve as sources of linoleic acid—an essential fatty acid that is needed for growth and healthy skin.

·         They add flavor and texture to food.

·         They satisfy hunger longer than other nutrients do.

Protein

•      Proteins are substances found in every cell. The body needs proteins to build and repair all body tissues. Protein is an important part of blood cells. Proteins are made up of carbon, hydrogen, oxygen, and nitrogen atoms that are formed into basic units called amino acids.

•      There are 20 different amino acids. Nine of them are essential, and the other eleven amino acids can be produced by the body.

The body uses proteins to:

·         Build new cells and tissues.

·         Replace damaged cells by making new ones.

·         Make enzymes, hormones, and antibodies.

·         Supply the body with energy.

 

 

Vitamins and Minerals

Vitamins are essential for:

–     Building body tissues such as bones, skin, glands, nerves, and blood.

–     Assisting in the metabolizing of proteins, fats, and carbohydrates so you receive energy from food.

–     Promoting healing

–     Preventing nutritional deficiency diseases.

Minerals are essential for:

–     The formation of strong bones and teeth

–     Helping to control the nervous system

–     Fluid balance in tissues

–     Muscle contractions

 

Minerals

•      Minerals are simple substances found in the environment that are essential to the body’s functioning.

•      Minerals are used to regulate a wide range of body processes, from bone formation to blood clotting, and they are important for the body structure.

•      Most minerals are either quickly used or lost in waste products, therefore we must eat mineral-rich foods daily to replenish our supply.

•       Iron is an exception –it tends to be kept and recycled by the body, except when there is a blood loss.

 

 

Malnutrition Problems in Nepal

 Major Malnutrition Problem

1. PEM (Protein Energy Malnutrition)

2. IDA (Iron Deficiency Anemia)

3. VAD ( Vitamin A Deficiency)

4. IDD (Iodine Deficiency Disorders)

 

 

 

1. PEM (Protein Energy Malnutrition)

•Inappropriate breastfeeding

•Inadequate complementary feeding practices

•Insufficient health services (Growth monitoring and counseling)

•Low birth weight

•Infectious diseases

•Inadequate energy intake

 

Consequences

•Failing to grow (underweight, stunted, and wasted)

•Reduced learning ability

•Reduced resistance and immunity against infection

•Reduced productivity in the future 

 

Causes

•Inadequate energy intake

•Inadequate knowledge and practice of maternal feeding

•Heavy physical workload

•Lack of extra food intake during pregnancy and lactation

 

2. Iron Deficiency Anemia (IDA)

 

Causes

•Inadequate intake of iron from daily diets

•Inadequate absorption of dietary iron

•Infestations such as hookworms and malaria

•High requirements of iron particularly during growth and pregnancy

•Blood loss (menstruation, and injury)

•Vitamin A deficiency

 

Consequences

•Impaired human function at all stages of life

•Impaired work performances, endurance and productivity

•Increased risk of maternal morbidity and mortality

•Increased risk of sickness and death for the baby

 

3. Vitamin A Deficiency (VAD)

 

Causes

•Low intake of Vitamin A from daily diets

•Restricted Vitamin A (VA) absorption

•Worm infestation

•Increased VA requirement resulting from infectious diseases

 

Consequences

•Xerophthalmia (Night blindness, Bitot’s spot, corneal ulcer, Keratomalacia, xerosis)

•Increased risk of morbidity and mortality

•Increased risk of anemia

 

4. Iodine Deficiency Disorders (IDD)

 

Causes

•Lack of Iodine in food

 

Consequences

•Cretinism

•Goiter

•Impaired cognitive function

•Increased prenatal morbidity and mortality

•Reduced productivity.

 

Tuberculosis

Tuberculosis

Definition

·        Tuberculosis remains a leading cause of infectious morbidity and mortality worldwide.

·        World Health Organization (WHO) called tuberculosis a "global emergency, 1993"

·        About 8 million new cases of tuberculosis each year.

·        Miliary tuberculosis is a systemic version of TB affecting many organ systems due to hematogenous spread.

Etiology

·         Mycobacterium tuberculosis—the major etiologic agent worldwide; humans are the sole reservoir

·         M. bovis—transmitted from milk of infected cows; rare since institution of pasteurization

·         M. africanum—rare; only in Africa

Risk Factors

• Occupational: healthcare workers—airborne transmission, infection from extrapulmonary disease such as draining an abscess, autopsies; embalmers—from body fluids generating infectious aerosols
• Contact with infected person
• Location of birth: Asia, Africa, Latin America
• HIV infection
• Residence in a long-term care facility
• Immunosuppressive therapy
• Tuberculosis infection: increases likelihood of developing active disease within two years
• Low income, medically underserved individuals
• In areas with a high incidence of TB, exogenous re-infection is a major cause of recurrence after effective treatment.

Signs and Symptoms

• Asymptomatic—especially from initial infection
• Mild fever, headache, chills, night sweats
• Malaise, fatigue
• Anorexia, weight loss
• Cough—nonproductive or mucopurulent
• Hemoptysis
• Pleuritic chest pain
• Dyspnea
• Adenopathy
• Children—asymptomatic and extrapulmonary manifestations are more frequent than in adults; look for signs of meningitis, adenopathy

Differential Diagnosis

• Bacterial pneumonia
• Other nontubercular mycobacterial infections
• Lymphomas
• Sarcoidosis
• Lung abscess

Drug Therapies

Standard antibiotics for tuberculosis include:

• Isoniazid—adults 5 mg/kg/day, children 10 to 20 mg/kg/day, 300 mg maximum for both; side effects: hepatitis (risk increased with alcohol consumption), peripheral neuropathy, rash, fever; additional drug interactions and toxicity for patients with HIV
• Rifampin—adults 10 mg/kg/day, maximum 600 mg/day, children 10 to 20 mg/kg/day; side effects: gastrointestinal upset, hepatitis, orange discoloration of body fluids (and contact lenses); additional drug interactions and toxicity for patients with HIV
• Pyrazinamide—15 to 30 mg/kg/day, 2 g maximum; side effects: hepatitis, hyperuricemia possibly with polyarthralgias (both reduced by concurrent rifampin administration)
• Ethambutol—least potent against M. ; 15 to 25 mg/kg/day for 2 months, then reduce to 15 mg/kg/day; side effects: retrobulbar optic neuritis and color perception problems, avoid with children
• Streptomycin—used least often because of toxicity; intramuscular or intravenous administration of 10 to 15 mg/kg/day, maximum 1 g/day, up to 5 times per week for adults, 20 to 40 mg/kg/day with 1 g/day maximum for children; side effects: ototoxicity (both hearing loss and vestibular dysfunction), nephrotoxicity, teratogenic
• Pyridoxine (vitamin B₆) added to regimen particularly in populations at risk for vitamin deficiency (e.g., malnourished, alcoholics, elderly, pregnant and nursing mothers) or at risk for neuropathy (diabetics, HIV, chronic renal failure)

Experimental drugs:

• Rifapentine—longer acting, allowing dosing twice a week
• Fluoroquinolones (e.g., ciprofloxacin)—antibacterial; concentrations higher in respiratory secretions than in serum; well tolerated, but insufficient data to use as standard treatment; less effective with HIV
• Rifabutin—as effective as rifampin with concurrent HIV, but reduces time to sputum conversion; 150 mg/day associated with fewest adverse effects; possible role with multidrug resistance

TUBERCULOSIS THERAPY

Based on antitubercular activity

1.      Tuberculocidal agents – Isoniazid, Rifampicin, Streptomycin, pyrazinamide, capreomycin, Kanamycin, Ciprofloxacin.

2.      Tuberculostatic agents – Ethambutol, ethionamide, thiacetazone, cycloserine, PAS.

First line drugs

Isoniazid (INH) – Tuberculocidal for rapidly multiplying bacilli but static for resting bacilli.

INH destroys:

a)      intracellular bacilli as it penetrates into the cells, and

b)      Bacilli multiplying in the walls of the cavities.

Thus it is effective against both intra and extracellular organisms.If used alone, mycobacteria develop resistance.

Mechanism of action: INH inhibits the synthesis of mycolic acids which is an important component of the mycobacterial cell wall.

Pharmacokinetics: INH is completely absorbed orally, penetrates all tissues, tubercular cavities, necrotic tissues and CSF. It is metabolised by acetylation. Metabolites are excreted in urine.

ADRs: Peripheral neuritis (due to interference with utilization and increased excretion of pyridoxine) can be avoided by giving prophylactic pyridoxine (10 – 50 mg) with INH.

Hepatitis, CNS toxicity, anorexia etc.

Rifampicin – Antibiotic obtained from Streptomyces mediterranei.

The other rifamycins are rifabutin and rifapentine.

Rifampicin is bactericidal to M.tuberculosis, M.leprae and atypical mycobacteria. Also inhibits, most Gram +ve and –ve bacteria like Staph.aureus, N.meningitidis, E.coli, Proteus, Pseudomonas and legionella.

Antitubercular action: Only drug acts on persisters; acts on both intra and extracellular organisms & is effective against TB bacilli resistant to other drugs.

MOA: Rifampicin binds to DNA dependent RNA polymerase and inhibits RNA synthesis in the bacteria.

Pharmacokinetics: has good tissue penetrability – reaches caseous material, cavities and CSF; It also appears in saliva, tears, sweat.

It is a microsomal enzyme inducer.

ADRs: Skin rashes, diarrhoea, nephritis & hepatotoxicity.

It stains the secretions including tears, saliva and sweat orange red.

Use:

1.      TB and atypical mycobacterial infections.

2.      Leprosy

3.      Prophylaxis of H.influenza and meningococcal meningitis

4.      Resistant staphylococcal infections.

5.      Brucellosis – Rifampicin 600 – 900 mg+ Doxy 200 mg daily for 6 weeks.

6.      To eradicate carrier state – rifampin eradicates the nasal carrier state of N.meningitidis, H.influenza and S.aureus – 600 mg BD for 2 days.

Rifubutin: similar to Rifampicin, may be used in TB pts with AIDS who are receiving antiviral drugs.

Rifapentine – analog of Rifampicin.

Pyrazinamide: Tuberculocidal,

MOA not known.

It is effective against intracellular bacilli.

ADRs: Hepatotoxicity

Hyperuricaemia – due to ↓excretion of uric acid may result in gouty arthritis.

Arthralgia, vomiting etc.

Streptomycin: Tuberculocidal, acts against extracellular organisms due to poor penetrating power.

Second line drugs

Ethambutol: Tuberculostatic, acts on fast multiplying bacilli in the cavities. Also effective against atypical mycobacteria.

It inhibits the incorporation of mycolic acids into the mycobacterial cell wall.

Optic neuritis resulting in ↓ visual acuity and inability to differentiate red from green is an important ADR which needs withdrawal of the drug. Colour vision should be monitored during treatment.

Anorexia, headache, fever, allergic reactions.

Thiacetazone: Tuberculostatic with low efficacy.

It delays the development of resistance to other drugs.

ADRs: Hepatotoxicity, dermatitis, GI side effects.

Ethionamide: Tuberculostatic, effective against both intra and extracellular organisms.

It is also effective in atypical mycobacteria.

ADRs: Anorexia, metallic taste in the mouth, hepatitis, peripheral neuritis.

Ethionamide is a secondary agent used only when primary drugs are ineffective.

Para-aminosalicylic acid (PAS): related to sulfonamides is tuberculostatic.

GI effects like nausea, anorexia & epigastric pain and diarrhoea make it poorly tolerated drug.

Rarely used.

Other second line drugs

Amikacin, kanamycin and capreomycin – They are oto and nephrotoxic and are used only in resistant cases.

Amikacin is effective against atypical mycobacteria.

Cycloserine – antibiotic that inhibits cell wall synthesis, is tuberculostatic, also effective against some gram-positive organisms.

It causes CNS toxicity including headache, tremors, psychosis and sometimes seizures. It is used only in resistant TB.

Fluoroquinolones – Ciprofloxacin, ofloxacin and sparfloxacin inhibit TB bacilli and atypical mycobacteria.

They are useful in multidrug resistant TB in combination with other drugs.

Treatment of TB

A combination of trt is given to

- delay the development of resistance

- reduce toxicity

- shorten the course of trt.

Chemotherapy is given in 2 phases –

-       First phase – initial, intensive phase of 1 – 3 months duration aimed at killing as many as possible.

-       Second phase – continuation phase to destroy the dormant or persisters – duration 6 – 9 months.

Short-term regimens

Directly Observed Treatment (DOT) is a strategy that is found to be effective & is recommended throughout the world.

INH + R + Z + E/S daily for 2 months

Followed by

INH + R daily for 4 months.

Role of glucocorticoids:

As steroids depress host defense mechanisms, they should be used only in conditions like TB meningitis, miliary TB, pleural effusion, renal TB.

Steroids suppress inflammatory reaction which can lead to extensive fibrosis and damage.

Rifampicin – 600 mg

INH      - 300 mg

Pyrazinamide – 2000 mg

Ethambutol - 1500 mg

Streptomycin – 1 gm