Chapter 14
INFECTIOUS DISEASES
Meningitis
- Meningitis is an Inflammation of brain and spinal cord membranes (meninges). The meninges are the three membranes that cover the brain and spinal cord. Meningitis can occur when fluid surrounding the meninges becomes infected. The most common causes of meningitis are viral and bacterial infections, but can also be cancer, chemical irritation, fungi and drug allergies. Viral and bacterial meningitis are contagious. They can be transmitted by coughing, sneezing or close contact.
Types of Meningitis
- Viral and bacterial infections are the most common causes of meningitis. There are several other forms of meningitis. Examples include cryptococcal, which is caused by a fungal infection, and carcinomatous, which is cancer-related. These types are rare.
- Viral Meningitis: Viral meningitis is the most common type of meningitis. Viruses in the Enterovirus category cause 85 % of cases. Viruses in the Enterovirus category cause about 10 to 15 million infections per year, but only a small percentage of people who get infected will develop meningitis. These are more common during the summer and fall, and they include:
Coxsackievirus A
Coxsackievirus B
Echoviruses
Other viruses can cause meningitis. These include:
West Nile virus
Influenza
Mumps
HIV Measles
Herpes viruses
Coltivirus, which causes Colorado tick fever.
- Bacterial Meningitis: Bacterial meningitis is contagious and caused by infection from certain bacteria. It is fatal if left untreated. Between 5 to 40 % of children and 20 to 50 % of adults with this condition die. This is true even with proper treatment. The most common types of bacteria that cause bacterial meningitis are:
- Streptococcus pneumoniae: It is typically found in the respiratory tract, sinuses and nasal cavity, and can cause meningitis called “pneumococcal meningitis.”
- Neisseria meningitides: It is spread through saliva and other respiratory fluids and causes meningitis called “meningococcal meningitis.
- Haemophilus influenza: This can cause not only meningitis but infection of the blood, inflammation of the windpipe, cellulitis, and infectious arthritis.
Clinical Features and Pathophysiology
Chills, Rigors or Fever:
Endogenous cytokines (released during
the immune response to the invading
pathogens) affect the thermoregulatory
neurons of the hypothalamus, changing
the central regulation of body
temperature. Invading viruses or bacteria produce
exogenous substances (pyrogens) that
can also re-set the hypothalamic thermal
set point.
Nuchal rigidity (neck stiffness): Flexion of the spine leads to stretching of the meninges. In meningitis, traction on the inflamed meninges is painful, resulting in limited range of motion through the spine (especially in the cervical spine).
Altered mental status: ↑ ICP → brain herniation → damage to the reticular formation (structure in the brainstem that governs consciousness).
Complications
Longer the cause of the disease without
treatment, the greater the risk of seizures
and permanent neurological damage. These
following complications are typically
associated with meningitis:
- Seizures
- Hearing loss
- Gait problems
- Memory difficulty
- Learning disabilities
- Brain damage
- Hydrocephalus
- A subdural effusion, or a buildup of fluid between the brain and the skull
- Kidney failure
- Shock
- Death
Symptoms
Risk Factors
The following are some of the risk
factors for meningitis:
Compromised Immunity: An immune
deficiency is more vulnerable to cause
meningitis infections. Certain disorders and
treatments can weaken immune system.
These include:
- HIV
- AIDS
- Autoimmune disorders
- Chemotherapy
- Organ or bone marrow transplants
Cryptococcal meningitis, which is caused by a fungus, is the most common form of meningitis in people with HIV or AIDS.
Community Living: Meningitis is easily
spread when people live in close quarters.
Being in small spaces increase the chance of
exposure. Examples of these locations
include:
- College dormitories
- Barracks
- Boarding schools
- Day care centers
Pregnancy: Pregnant women have an increased risk of listeriosis, which is an infection caused by the Listeria bacteria. Infection can spread to the unborn child.
Age: All ages are at risk for meningitis. Children under the age of 5 are at increased risk of viral meningitis. Infants are at higher risk of bacterial meningitis.
Working with Animals: Farm workers
and others who work with animals have an
increased risk of infection with Listeria.
Diagnosis
- Physical exam: Physical exams like monitoring of fever, an increased heart rate, neck stiffness and reduced consciousness can be important clues for diagnosis of meningitis in early stage.
- Lumbar puncture: This test is also called a spinal tap. It allows looking for increased pressure in the central nervous system. It can also find inflammation or bacteria in the spinal fluid. This test can also help to determine the best antibiotic for treatment.
- Blood cultures: Identification of bacteria in the blood. Bacteria can travel from the blood to the brain. N. meningitidis and S. pneumoniae can cause both sepsis and meningitis.
- Complete blood count: A complete blood count with differential is a general index of health. It checks the number of red and white blood cells in blood. White blood cells fight infection. The count is usually elevated in meningitis.
- Chest X-rays: Chest X-rays can reveal the presence of pneumonia, tuberculosis, or fungal infections. Meningitis can occur after pneumonia.
- CT scan: A CT scan of the head may show problems like a brain abscess or sinusitis. Bacteria can spread from the sinuses to the meninges.
Treatment
Bacterial or severe viral meningitis may
require treatment in a hospital, including:
- Medicines such as antibiotics, corticosteroids, and medicines to reduce fever.
- Oxygen therapy, for patients have trouble breathing.
- Supportive care. In the hospital, watch the person closely and provide care if needed. For example, if patient may need to drink extra liquids or get fluids in a vein (IV).
Prevention
- Maintaining a healthy lifestyle
- Getting adequate amounts of rest
- Not smoking
- Avoiding contact with sick people,
- Vaccinations can also protect against certain types of meningitis. Vaccines that can prevent meningitis include the following
- Haemophilus influenzae type B (Hib) vaccine
- Pneumococcal conjugate vaccine
- Meningococcal vaccine
Typhoid Fever
- Typhoid fever is also called enteric fever. It is an acute infectious illness associated with fever that is most often caused by the Salmonella typhi bacteria. It can also be caused by Salmonella paratyphi, a related bacterium that usually leads to a less severe illness. The bacteria are deposited through fecal contamination in water or food by a human carrier and are then spread to other people in the area. Typhoid fever is rare in industrial countries but continues to be a significant public health issue in developing countries.
Pathophysiology
- All the pathogenic Salmonella species, when present in the gut are engulfed by phagocytic cells, which then pass them through the mucosa and present them to the macrophages in the lamina proprietor. Nontyphoidal salmonellae are phagocytized throughout the distal ileum and colon. With toll-like receptor (TLR)–5 and TLR4/MD2/CD-14 complex, macrophages recognize pathogen-associated molecular patterns (PAMPs) such as flagella and lipopolysaccharides. Macrophages and intestinal epithelial cells then attract T cells and neutrophils with interleukin 8 (IL-8), causing inflammation and suppressing the infection.
- In contrast to the nontyphoidal salmonellae, S typhi and paratyphi enter the host's system primarily through the distal ileum. They have specialized fimbriae that adhere to the epithelium over clusters of lymphoid tissue in the ileum (Peyer patches), the main relay point for macrophages traveling from the gut into the lymphatic system. The bacteria then induce their host macrophages to attract more macrophages.
- The bacteria then infect the gallbladder via either bacteremia or direct extension of infected bile. The result is that, the organism re-enters the gastrointestinal tract in the bile and reinfects Peyer patches. Bacteria that do not reinfect the host are typically shed in the stool and are then available to infect other hosts.
Epidemiology
Typhoid fever occurs worldwide,
primarily in developing nations whose
sanitary conditions are poor. Typhoid fever
is endemic in Asia, Africa, Latin America, the
Caribbean, and Oceania, but 80% of cases
come from Bangladesh, China, India,
Indonesia, Laos, Nepal, Pakistan, or
Vietnam. Within those countries, typhoid
fever is most common in underdeveloped
areas. Typhoid fever infects roughly 21.6
million people (incidence of 3.6 per 1,000
population) and kills an estimated 200,000
people every year. In the United States,
most cases of typhoid fever arise in
international travelers. The average yearly
incidence of typhoid fever per million
travelers from 1999-2006 by country or
region of departure was as follows:
- Canada - 0
- Western hemisphere outside Canada / United States - 1.3
- Africa - 7.6
- Asia - 10.5
- India - 89 (122 in 2006)
- Total (for all countries except Canada/United States) - 2.2
Symptoms and Complications
Symptoms usually appear 1 or 2 weeks
after infection but may take as long as 3
weeks to appear. Typhoid usually causes a
high, sustained fever, often as high as 40°C
(104°F), and extreme exhaustion.
Other common symptoms include:
- Constipation
- Cough
- Headache
- Loss of appetite
- Stomach pains
- Sore throat
- Bleeding from the rectum
- Delirium
- Diarrhoea.
Diagnosis
Infection with typhoid or paratyphoid
fever results in a low-grade septicemia. It is
diagnosed as follows:
Differential Diagnosis:
The group of symptoms which most
clearly suggests the diagnosis of typhoid
fever is:
- Gradually increasing fever with evening exacerbation and morning remission
- General malaise with headache
- Furred tongue with red edges and tip
- Epistaxis
- Relatively slow pulse (possibly dicrotic)
- Abdominal distension with increased bowel sounds
- Tenderness in the right iliac fossa on firm pressure
- A roseolar eruption confined principally to the abdomen and chest
- Splenomegaly
- Bronchial catarrh.
Organism Culture:
- Diagnosis is made by culturing the organism. This may be obtained from stool or other sources
- Blood cultures are only positive in 40- 60% of cases. However, this may be enhanced to above 80% using two sets of blood cultures and modern methods
- The most sensitive source (90% isolation rate) is bone marrow aspiration
- Isolation of S. typhi is highest in the first week and becomes more difficult as time passes.
- The traditional serological test is Widal's test. It measures agglutinating antibodies against flagellar (H) and somatic (O) antigens of S. typhi
- High or rising O antibody titres generally indicate acute infection, whereas H antibody is used to identify the type of infection
- The test is positive on admission in between 40-60% of patients but the test has enormous variation between laboratories in terms of sensitivity, specificity and predictive value
- The validity of rapid diagnostic tests for typhoid and paratyphoid was submitted for Cochrane review in 2010
Treatment
Typhoid fever is treated with antibiotics
that kill the Salmonella bacteria. Prior to the
use of antibiotics, the fatality rate was 20%.
Death occurred from overwhelming
infection, pneumonia, intestinal bleeding, or
intestinal perforation. With antibiotics and
supportive care, mortality has been reduced to 1%-2%. With appropriate antibiotic
therapy, there is usually improvement within
one to two days and recovery within seven
to 10 days. Several antibiotics are effective
for the treatment of typhoid fever.
- Chloramphenicol was the original drug of choice for many years. Because of rare serious side effects, chloramphenicol has been replaced by other effective antibiotics.
- Fluoroquinolones like Ciprofloxacin, Gatifloxacin, and Ofloxacin are the most frequently used drugs for nonpregnant patients.
- Ceftriaxone an intramuscular injection medication is an alternative for pregnant patients.
- Ampicillin and trimethoprimsulfamethoxazole is frequently prescribed antibiotics although resistance has been reported in recent years.
- Antipyretic therapy is used if required.
- Steroids have occasionally been used in severe cases. However, they may induce relapse, so are not generally recommended.
- Surgical - if perforation of the bowel occurs, it will require closure. Treatment with antibiotics alone was once favoured but simple closure and drainage are required.
Complications
- The two most common complications are haemorrhage (including disseminated intravascular coagulation) and perforation of the bowel. Before antibiotics, perforation had a mortality of around 75%.
- Jaundice may be due to hepatitis, cholangitis, cholecystitis or haemolys Pancreatitis with acute kidney injury and hepatitis with hepatomegaly are rare.
- Toxic myocarditis occurs in 1-5% of patients (ECG changes may be present). It is a significant cause of death in endemic areas.
- Toxic confusional states and other neurological and psychiatric disturbances have been reported.
Prevention
- Wash hands thoroughly with soap and water after going to the toilet and before eating.
- Boil or disinfect all water before drinking it – use disinfectant tablets or liquid available in pharmacies or drink commercially bottled (preferably carbonated) beverages.
- Peel all fruit and vegetable skins before eating.
- Keep flies away from food.
- Watch out for ice cubes, ice cream, and unpasteurized milk, which can easily be contaminated.
- Cook all food thoroughly and eat it while it is hot.
- Be aware of the "danger foods” shellfish, salads, and raw fruit and vegetables.
- Do not eat food or drink beverages from street vendors.
Leprosy
- Leprosy (also known as Hansen’s disease) is an infection caused by slow-growing bacteria called Mycobacterium leprae or M. lepromatosis bacteria. It is a slowly developing (from six months to 40 years), progressive disease that damages the skin and nervous system. It results in skin lesions and deformities, most often affecting the cooler places on the body (for example, eyes, nose, earlobes, hands, feet and testicles). The skin lesions and deformities can be very disfiguring and are the reason that infected individuals historically were considered outcasts in many cultures. Although human-to-human transmission is the primary source of infection, three other species can carry and (rarely) transfer M. leprae to humans: chimpanzees, mangabey monkeys, and nine-banded armadillos. The disease is termed a chronic granulomatous disease, similar to tuberculosis, because it produces inflammatory nodules (granulomas) in the skin and nerves over time.
- The disease has been known to man since time immemorial. DNA taken from the shrouded remains of a man discovered in a tomb next to the old city of Jerusalem shows him to be the earliest human proven to have suffered from leprosy. The remains were dated by radiocarbon methods to 1–50 A.D. The disease probably originated in Egypt and other Middle Eastern countries as early as 2400 BCE. An apparent lack of knowledge about its treatment facilitated its spread throughout the world. Mycobacterium leprae, the causative agent of leprosy, was discovered by G. H. Armauer Hansen in Norway in 1873, making it the first bacterium to be identified as causing disease in humans. Over the past 20 years, the WHO implementation of MDT has rendered leprosy a less prevalent infection in 90% of its endemic countries with less than one case per 10,000 populations. Though, it continues to be a public health problem in countries like Brazil, Congo, Madagascar, Mozambique, Nepal, and Tanzania
- Borderline, or dimorphous, Hansen’s disease: It is the most common form. When compared to tuberculoid or lepromatous forms, it is of intermediate severity. The skin lesions seem to be of the tuberculoid type, but are more numerous, and may be found anywhere on the body. Peripheral nerves are affected as well, with ensuing weakness and anesthesia.
Pathogenesis of Leprosy
- Onset of leprosy is insidious. It affects nerves, skin and eyes. It may also affect mucosa (mouth, nose and pharynx), testes, kidney, voluntary/smooth muscles, reticuloendothelial system, and vascular endothelium.
- Bacilli enter the body usually through respiratory system. It has low pathogencity, only a small proportion of infected people develop signs of the disease. Though infected, majority of the population do not develop the disease. After entering the body, bacilli migrate towards the neural tissue and enter the Schwann cells. Bacteria can also be found in, macrophages, muscle cells and endothelial cells of blood vessels.
- As the bacilli multiply, bacterial load increases in the body and infection is recognized by the immunological system. Lymphocytes and histiocytes (macrophages) invade the infected tissue. At this stage, clinical manifestation may appear as involvement of nerves with impairment of sensation and/or skin patch. If it is not diagnosed and treated in the early stages, further progress of the diseases is determined by the strength of the patient’s immune response. Specific and effective cell mediated immunity (CMI) provides protection to a person against leprosy. When specific CMI is effective in eliminating/ controlling the infection in the body, lesions heal spontaneously or it produces pauci-bacillary (PB) type of leprosy
Epidemiology
- M. leprae is a fastidious, acid-fast, intracellular pathogen. In 2008, there were approximately 250,000 new cases reported, predominantly in India, Brazil and Indonesia. Humans were previously thought to be the only important reservoirs of the bacteria, but it is now appreciated that leprosy, or Hansen's disease, may also be acquired from environmental sources. Leprosy is likel transmitted by aerosol droplets taken up through nasal or other upper airway mucosa, where it has been detected by PCR techniques. Large number of organisms have been found in the nasal secretions of lepromatous leprosy patients.
Signs and Symptoms
Symptoms mainly affect the skin, nerves,
and mucous membranes (the soft, moist
areas just inside the body’s openings). The
disease can cause skin symptoms such as:
Discoloured patches of skin, usually flat, that may be numb and look faded (lighter than the skin around). •
- Growths (nodules) on the skin.
- Thick, stiff or dry skin.
- Painless ulcers on the soles of feet.
- Painless swelling or lumps on the face or earlobes.
- Loss of eyebrows or eyelashes. Symptoms caused by damage to the nerves are:
- Numbness of affected areas of the skin.
- Muscle weakness or paralysis (especially in the hands and feet).
- Enlarged nerves (especially those around the elbow and knee and in the sides of the neck).
- Eye problems that may lead to blindness (when facial nerves are affected). Symptoms caused by the disease in the mucous membranes are:
- A stuffy nose and nose bleeds.
Diagnosis
- Diagnosis The majority of cases of leprosy are diagnosed by clinical findings, especially since most current cases are diagnosed in areas that have limited or no laboratory equipment available. Hypopigmented patches of skin or reddish skin patches with loss of sensation, thickened peripheral nerves, or both clinical findings together often comprise the clinical diagnosis. Skin smears or biopsy material that show acidfast bacilli with the Ziehl-Neelsen stain or the Fite stain (biopsy) can diagnose multibacillary leprosy, or if bacteria are absent, diagnose Paucibacillary leprosy.
- Other tests can be done, but most of these are done by specialized labs and may help a clinician to place the patient in the more detailed Ridley-Jopling classification and are not routinely done (lepromin test, phenolic glycolipid-1 test, PCR, lymphocyte migration inhibition test or LMIT). Other tests such as CBC test, liver function tests, creatinine test, or a nerve biopsy may be done to help determine if other organ systems have been affected
Treatment
- Paucibacillary leprosy is treated with two antibiotics, dapsone and rifampicin, while multibacillary leprosy is treated with the same drugs, in addition with another antibiotic, clofazimine. Usually, the antibiotics are given for at least six to 12 months or more to cure the disease.
- Multibacillary leprosy can be kept from advancing, and living. M. leprae can be essentially eliminated from the person by antibiotics, but the damage occured before administration of antibiotics is usually not reversible. Recently, the WHO suggested that single-dose treatment of patients with only one skin lesion with rifampicin, minocycline (Minocin), or ofloxacin (Floxin) is effective.
- Steroid medications have been used to minimize pain and acute inflammation with leprosy
Complications
Without treatment, leprosy can
permanently damage your skin, nerves,
arms, legs, feet and eyes.
Complications of leprosy can include:
- Blindness or glaucoma.
- Disfiguration of the face (including permanent swelling, bumps and lumps).
- Erectile dysfunction and infertility in men.
- Kidney failure.
- Muscle weakness that leads to claw-like hands or an inability to flex the feet.
- Permanent damage to the inside of the nose, which can lead to nose bleeds and a chronic, stuffy nose. Permanent damage to the nerves outside the brain and spinal cord, including those in the arms, legs and feet
Prevention
- The prevention of leprosy ultimately lies in the early diagnosis and treatment of those individuals suspected or diagnosed as having leprosy, thereby preventing further transmission of the disease to others.
- Public education and community awareness are crucial to encourage individuals with leprosy and their families to undergo evaluation and treatment with MDT.
- Household contacts of patients with leprosy should be monitored closely for the development of leprosy signs and symptoms.
- A study demonstrated that prophylaxis with a single dose of rifampicin was 57% effective in preventing leprosy for the first two years in individuals who have close contact with newly diagnosed patients with leprosy
Tuberculosis
There are many subgroups in the genus mycobacterium such as Maviumintracellulare, Mkansasii, M bovis, but M tuberculosis alone is pathogenic in human. Mycobacterium
tuberculosis, most commonly affects the lungs. It is transmitted from person to person via
droplets from the throat and lungs of people with the active respiratory disease. Most
commonly, tuberculosis is caused by air-borne infection.
In healthy people, infection with Mycobacterium tuberculosis often causes no symptoms, since the person's immune system acts to “wall off” the bacteria. Most people who are exposed to TB never develop symptoms because the bacteria can live in an inactive form in the body. But if the immune system weakens, such as immunocompromised (HIV) or elderly adults, TB bacteria can become active and their active state causes death of tissue in the organs they infect. Active TB disease can be fatal if left untreated.
Epidemiology
Tuberculosis is one of India's major
public health problems. According to WHO
estimates, India has the world's largest
tuberculosis epidemic and approximately
two to three million people are infected with
tuberculosis out of a global incidence of 8.7
million cases. This is a public health
problem. India bears a disproportionatel large burden of the world's tuberculosis
rates, as it resides to be the biggest health
problem in India.
Etiology
Tuberculosis is caused by Mycobacterium
tuberculosis, which spread from person to
person through microscopic droplets
released into the air. This can happen when
someone with the untreated, active form of
tuberculosis, coughs, speaks, sneezes, spits,
laughs or sing
Risk Factor
Risk Factor
The person more prone to the infection
includes:
- Immigration and infection with HIV
- Frequent and prolonged contact
- Host debilitation due to malnutrition enhance risk of transmission (condition exist in refugee and living in poverty).
- Opportunistic infection (immunocompromised)
- Other risk factors include old age, alcoholism, diabetes and environmental lungs disease.
Pathophysiology
- Infection with TB requires inhalation of droplet nuclei. Following deposition in the alveoli, Mycobacterium tuberculosis is engulfed by alveolar macrophages, but survives and multiplies within the macrophages. Proliferating bacilli kill macrophages and are released; this event produces a response from the immune system. Exposure may lead to clearance of Mycobacterium tuberculosis, persistent latent infection, or progression to primary disease. Successful containment of TB is dependent on the cellular immune system, mediated primarily through T-helper.
- Approximately 10% of individuals with latent infection will progress to active disease over their lifetime. The risk is greatest within the two years following initial acquisition of M. tuberculosis. A number of conditions can alter this risk, particularly HIV infection, in which the annual risk of developing active TB is 8% to 10%. Immunocompromised conditions and treatment with immunosuppressing medicines, including systemic corticosteroids and TNF-α antagonists, also contribute to re-activation.
Clinical Manifestations
During initial infection and granulomas,
there are no symptoms of mild bronchial
pneumonia but sputum test is positive.
In active TB, sign of chronic
inflammation include:
- Anorexia
- Overall sensation of feeling unwell
- Weight loss
- Fatigue
- Low grade fever
- Night sweating
- Coughing that lasts longer than 2 weeks with green, yellow, or bloody sputum
- Shortness of breath
- Chest pain
- Hemoptysis.
Diagnosis
Medical history and physical exam
include checking the symptoms such as an
ongoing cough, fatigue, fever, loss of
weight, anorexia and night sweats.
- Sputum cytology: Examination of sample of sputum (mucus) under a microscope to determine whether abnormal cells are present. It may be done to help detect certain non-cancerous lung conditions, such as pneumonia or inflammatory diseases, or the buildup of asbestos fibers in the lung.
- Test for TB Infection: The Mantoux tuberculin skin test (TST) or the TB blood test can be used to test for M. tuberculosis infection.
- Chest X-ray: A posterior-anterior chest radiograph is used to detect chest abnormalities. Lesions may appear anywhere in the lungs and may differ in size, shape, density, and cavitation. These abnormalities may suggest TB, but cannot be used to definitively diagnose TB. However, a chest radiograph may be used to rule out the possibility of pulmonary TB in a person who has had a positive reaction to a TST or TB blood test and no symptoms of disease.
Treatment
- Treatment for TB depends on whether it is active or latent. Patient may be hospitalized or suggested to avoid contact with other people until tests show that the patient is not contagious.
- Antibiotics: For TB lung infections, antituberculosis drugs eg. isoniazid, rifampicin, ethambutol, Pyrazinamide and streptomycin (Ist line) drugs are more effective. While para-amino salicylic acid, thiacetazone, ethionamide, cycloserine, kanamycin and rifabutin are IInd line drugs. A number of new drugs are available to overcome the current drug resistant combination treatment including: bedaquiline, delamanid, linezolid and sutezolid.
- Vaccination: A vaccine is available to limit the spread of bacteria after TB infection: The vaccine is generally used in countries or communities where the risk of TB infection is greater than 1% each year. It is used in new borns in these communities to prevent TB and its complications in the first few years of life.
- DOT: DOTS (directly observed treatment, short-course), is the name given to the World Health Organization recommended tuberculosis control strategy that combines five components:
Clinical Features
- MTB has remarkable tendency to develop resistance against antitubercular drugs. The drug treatment must be continued for many months, often an year or more. In the long period, the tubercule bacteria can become resistant to the drug even though the person is receiving antitubercular drugs. To prevent the development of resistance, one must use two or more drugs concurrently.
- Drug treatment consist of Ist line and IInd line drugs.
- Compliance: One major trouble is noncompliance of the patient. This is global phenomenon but more common in poor countries. If compliance is good and the patient is immunocompetent, the cure rate is excellent, nearly 100%. Where compliance is defective recurrence rate is high.
- Host defense is also an important factor
Prevention
- Education and screening: To reduce risk of infection and transmission, peoples with close contact with patient may undergo prophylactic therapy. To minimize air born infection use protective measures such as covering mouth and nose when coughing. Do not spend long periods of time in stuffy, enclosed rooms with anyone who has active TB until that person has been treated for at least 2 weeks. Someone who has active TB, help and encourage the person to follow treatment instructions.
- Early diagnosis and treatment: TB should be treated early in order to prevent deterioration of the disease and spread of the infection.
- Leading a healthy life style: The germs attack the lungs when a person's body resistance is reduced. Try to guard by leading a healthy lifestyle in order to minimize the chance of contracting the illness. This includes: adequate exercise, enough rest and sleep, balanced diet, avoidance of smoking and alcohol, breathing fresh air and maintaining good indoor ventilation
Urinary Tract Infection
Urinary tract infection (UTI) is second to respiratory infection as the most common type
of infection in the body. It is a bacterial infection involving the kidneys, ureters, bladder, or
urethra. These are the structures that urine passes through before being eliminated from the
body.
The upper urinary tract is composed of the kidneys and ureters and lower urinary tract
consists of the bladder and the urethra.
Types
- An infection affects the lower urinary tract (urethra or bladder), it may be called Urethritis, or Cystitis, if it only affects the bladder. If it migrates to and affects the upper urinary tract (ureters or kidneys) it is called Ureteritis and if it affects just the kidneys, it is called Pyelonephritis.
- Urinary tract infections are much more common in adults than in children, but about 1%-2% of children do get urinary tract infections. Urinary tract infections in children (besides bedwetting) are more likely to be serious than those in adults and should not be ignored (especially in younger children).
Causes of UTIs
- More than 90% of UTI cases are a type of bacteria called Escherichia coli, (E. coli). These bacteria normally live in the bowel and around the anus. E. coli bacteria are fairly sedate in its natural environment of the bowel. However, the bacteria will thrive when introduced to urine’s acidic state.
- Urinary tract infections normally occur when E.coli bacteria get into the urine and begin to grow. The infection usually starts at the opening of the urethra where the urine leaves the body and moves upward into the urinary tract to the bladder. If the infection is not treated at this point, it will continue on and quickly infect the kidneys.
- The normal process of urination flushes the bacteria out through the urethra. However, if the infection has already taken hold and there are too many bacteria, urinating may not stop their spread. The danger here is the infection spreading further. If it reaches the kidneys, it can cause a kidney infection (pyelonephritis), which can become a very serious and even life-threatening condition if not treated immediately
Risk Factors for UTIs
- Anything that reduces bladder emptying or irritates the urinary tract can cause UTIs.
- Obstructions: Blockages that make it difficult to empty the bladder can cause a UTI. Obstructions can be caused by an enlarged prostate, kidney stones and certain forms of cancer.
- Sexual Activity: Pressure on the urinary tract during sex can move bacteria from the colon into the bladder. Most women have bacteria in their urine after intercourse. However, the body usually can get rid of Symptomthese pathogens within 24 hours. Bowel bacteria may have properties that allow them to stick to the bladders .
- Bathroom Hygiene: Wiping from back to front after going to the bathroom can lead to a UTI. This motion drags bacteria from the rectal area towards the urethra.
- Condoms: Latex condoms can cause increased friction during intercourse. They may also irritate the skin. This may increase the risk of UTI in some individuals. However, condoms are important for reducing the spread of sexually transmitted infections
Tests and Diagnosis
Urinary tract infections do not always
cause signs and symptoms, but when they
do they may include:
- A strong, persistent urge to urinate.
- A burning sensation when urinating.
- Passing frequent, small amounts of urine
- Urine that appears cloudy.
- Urine that appears red, bright pink or cola coloured a sign of blood in the urine.
- Strong smelling urine.
- Pelvic pain, in women.
- Rectal pain, in men.
- UTIs may be overlooked or mistaken for other conditions in older adults
Treatments and Drugs
- Tests and procedures used to diagnose urinary tract infections include:
- Analyzing a urine sample: A urinary tract infection is diagnosis by detection of white blood cells, red blood cells or bacteria in patient's urine.
- Growing urinary tract bacteria in a lab: Lab analysis of the urine is sometimes followed by urine culture, a test that uses urine sample to grow bacteria in a lab. This test tells which bacteria are causing infection and helpful for selection of most effective medications.
- Creating images of your urinary tract: An ultrasound, a computerized tomography (CT) scan, intravenous pyelogram (IVP), use of X-rays with contrast dye to create images. These images are helpful to know abnormality in urinary tract which causes frequent infections.
Prevention
Not all UTIs can be prevented, but there
are some simple steps which can be taken to
reduce risk of developing and to help
prevent UTIs.
- Drinking water after having sex.
- Cleaning vaginal and rectal areas daily.
- Taking showers instead of baths
- Drink lots of fluids (six to eight glasses of water) to flush the urinary system.
- Urinate as soon as, feel the need rather than holding on.
- For women and girls, wipe bottom from front to back to prevent bacteria from around the anus entering the urethra.
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