Pneumococcus Health Dictionary

Streptococcus is a variety of gram-positive bacterium (see GRAM’S STAIN; BACTERIA) which under the microscope has much the appearance of a string of beads. Most species are saprophytic (see SAPROPHYTE); a few are PATHOGENIC and these include haemolytic types which can destroy red blood cells in a culture of blood agar. This o?ers a method of classifying the varying streptococcal strains. Alphahaeomolytic streptococci are usually associated with bacterial ENDOCARDITIS. SCARLET FEVER is caused by a ?-haeomolytic streptococcus called S. pyogenes. S. pneumoniae, also called PNEUMOCOCCUS, causes respiratory-tract infections, including PNEUMONIA. S. pyogenes may on its own, or with other bacteria, cause severe NECROTISING FASCIITIS or CELLULITIS in which oedema and death of subcutaneous tissues occur. The infection can spread very rapidly and, unless urgently treated with ANTIBIOTICS and sometimes surgery, death may quickly result. This spread is related to the ability of S. pyogenes to produce toxic substances called exotoxins. Although drug-resistant forms are occurring, streptococcal infections usually respond to treatment with antibiotics.... streptococcus

These consist either of expanding masses (lumps or tumours), or of areas of shrinkage (atrophy) due to degeneration, or to loss of blood supply, usually from blockage of an artery.

Tumours All masses cause varying combinations of headache and vomiting – symptoms of raised pressure within the inexpansible bony box formed by the skull; general or localised epileptic ?ts; weakness of limbs or disordered speech; and varied mental changes. Tumours may be primary, arising in the brain, or secondary deposits from tumours arising in the lung, breast or other organs. Some brain tumours are benign and curable by surgery: examples include meningiomas and pituitary tumours. The symptoms depend on the size and situation of the mass. Abscesses or blood clots (see HAEMATOMA) on the surface or within the brain may resemble tumours; some are removable. Gliomas ( see GLIOMA) are primary malignant tumours arising in the glial tissue (see GLIA) which despite surgery, chemotherapy and radiotherapy usually have a bad prognosis, though some astrocytomas and oligodendronogliomas are of low-grade malignancy. A promising line of research in the US (in the animal-testing stage in 2000) suggests that the ability of stem cells from normal brain tissue to ‘home in’ on gliomal cells can be turned to advantage. The stem cells were chemically manipulated to carry a poisonous compound (5-?uorouracil) to the gliomal cells and kill them, without damaging normal cells. Around 80 per cent of the cancerous cells in the experiments were destroyed in this way.

Clinical examination and brain scanning (CT, or COMPUTED TOMOGRAPHY; magnetic resonance imaging (MRI) and functional MRI) are safe, accurate methods of demonstrating the tumour, its size, position and treatability.

Strokes When a blood vessel, usually an artery, is blocked by a clot, thrombus or embolism, the local area of the brain fed by that artery is damaged (see STROKE). The resulting infarct (softening) causes a stroke. The cells die and a patch of brain tissue shrinks. The obstruction in the blood vessel may be in a small artery in the brain, or in a larger artery in the neck. Aspirin and other anti-clotting drugs reduce recurrent attacks, and a small number of people bene?t if a narrowed neck artery is cleaned out by an operation – endarterectomy. Similar symptoms develop abruptly if a blood vessel bursts, causing a cerebral haemorrhage. The symptoms of a stroke are sudden weakness or paralysis of the arm and leg of the opposite side to the damaged area of brain (HEMIPARESIS), and sometimes loss of half of the ?eld of vision to one side (HEMIANOPIA). The speech area is in the left side of the brain controlling language in right-handed people. In 60 per cent of lefthanders the speech area is on the left side, and in 40 per cent on the right side. If the speech area is damaged, diffculties both in understanding words, and in saying them, develops (see DYSPHASIA).

Degenerations (atrophy) For reasons often unknown, various groups of nerve cells degenerate prematurely. The illness resulting is determined by which groups of nerve cells are affected. If those in the deep basal ganglia are affected, a movement disorder occurs, such as Parkinson’s disease, hereditary Huntington’s chorea, or, in children with birth defects of the brain, athetosis and dystonias. Modern drugs, such as DOPAMINE drugs in PARKINSONISM, and other treatments can improve the symptoms and reduce the disabilities of some of these diseases.

Drugs and injury Alcohol in excess, the abuse of many sedative drugs and arti?cial brain stimulants – such as cocaine, LSD and heroin (see DEPENDENCE) – can damage the brain; the effects can be reversible in early cases. Severe head injury can cause localised or di?use brain damage (see HEAD INJURY).

Cerebral palsy Damage to the brain in children can occur in the uterus during pregnancy, or can result from rare hereditary and genetic diseases, or can occur during labour and delivery. Severe neurological illness in the early months of life can also cause this condition in which sti? spastic limbs, movement disorders and speech defects are common. Some of these children are learning-disabled.

Dementias In older people a di?use loss of cells, mainly at the front of the brain, causes ALZHEIMER’S DISEASE – the main feature being loss of memory, attention and reasoned judgement (dementia). This affects about 5 per cent of the over-80s, but is not simply due to ageing processes. Most patients require routine tests and brain scanning to indicate other, treatable causes of dementia.

Response to current treatments is poor, but promising lines of treatment are under development. Like Parkinsonism, Alzheimer’s disease progresses slowly over many years. It is uncommon for these diseases to run in families. Multiple strokes can cause dementia, as can some organic disorders such as cirrhosis of the liver.

Infections in the brain are uncommon. Viruses such as measles, mumps, herpes, human immunode?ciency virus and enteroviruses may cause ENCEPHALITIS – a di?use in?ammation (see also AIDS/HIV).

Bacteria or viruses may infect the membrane covering the brain, causing MENINGITIS. Viral meningitis is normally a mild, self-limiting infection lasting only a few days; however, bacterial meningitis – caused by meningococcal groups B and C, pneumococcus, and (now rarely) haemophilus – is a life-threatening condition. Antibiotics have allowed a cure or good control of symptoms in most cases of meningitis, but early diagnosis is essential. Severe headaches, fever, vomiting and increasing sleepiness are the principal symptoms which demand urgent advice from the doctor, and usually admission to hospital. Group B meningococcus is the commonest of the bacterial infections, but Group C causes more deaths. A vaccine against the latter has been developed and has reduced the incidence of cases by 75 per cent.

If infection spreads from an unusually serious sinusitis or from a chronically infected middle ear, or from a penetrating injury of the skull, an abscess may slowly develop. Brain abscesses cause insidious drowsiness, headaches, and at a late stage, weakness of the limbs or loss of speech; a high temperature is seldom present. Early diagnosis, con?rmed by brain scanning, is followed by antibiotics and surgery in hospital, but the outcome is good in only half of affected patients.

Cerebral oedema Swelling of the brain can occur after injury, due to engorgement of blood vessels or an increase in the volume of the extravascular brain tissue due to abnormal uptake of water by the damaged grey (neurons) matter and white (nerve ?bres) matter. This latter phenomenon is called cerebral oedema and can seriously affect the functioning of the brain. It is a particularly dangerous complication following injury because sometimes an unconscious person whose brain is damaged may seem to be recovering after a few hours, only to have a major relapse. This may be the result of a slow haemorrhage from damaged blood vessels raising intracranial pressure, or because of oedema of the brain tissue in the area surrounding the injury. Such a development is potentially lethal and requires urgent specialist treatment to alleviate the rising intracranial pressure: osmotic agents (see OSMOSIS) such as mannitol or frusemide are given intravenously to remove the excess water from the brain and to lower intracranial pressure, buying time for de?nitive investigation of the cranial damage.... brain, diseases of

In?ammation affecting the membranes of the BRAIN or SPINAL CORD, or usually both. Meningitis may be caused by BACTERIA, viruses (see VIRUS), fungi, malignant cells or blood (after SUBARACHNOID HAEMORRHAGE). The term is, however, usually restricted to in?ammation due to a bacterium or virus. Viral meningitis is normally a mild, self-limiting infection of a few days’ duration; it is the most common cause of meningitis but usually results in complete recovery and requires no speci?c treatment. Usually a less serious infection than the bacterial variety, it does, however, rarely cause associated ENCEPHALITIS, which is a potentially dangerous illness. A range of viruses can cause meningitis, including: ENTEROVIRUSES; those causing MUMPS, INFLUENZA and HERPES SIMPLEX; and HIV.

Bacterial meningitis is life-threatening: in the United Kingdom, 5–10 per cent of children who contract the disease may die. Most cases of acute bacterial meningitis in the UK are caused by two bacteria: Neisseria meningitidis (meningococcus), and Streptococcus pneumoniae (pneumococcus); other bacteria include Haemophilus in?uenzae (a common cause until virtually wiped out by immunisation), Escherichia coli, Mycobacterium tuberculosis (see TUBERCULOSIS), Treponema pallidum (see SYPHILIS) and Staphylococci spp. Of the bacterial infections, meningococcal group B is the type that causes a large number of cases in the UK, while group A is less common.

Bacterial meningitis may occur by spread from nearby infected foci such as the nasopharynx, middle ear, mastoid and sinuses (see EAR, DISEASES OF). Direct infection may be the result of penetrating injuries of the skull from accidents or gunshot wounds. Meningitis may also be a complication of neurosurgery despite careful aseptic precautions. Immuno-compromised patients – those with AIDS or on CYTOTOXIC drugs – are vulnerable to infections.

Spread to contacts may occur in schools and similar communities. Many people harbour the meningococcus without developing meningitis. In recent years small clusters of cases, mainly in schoolchildren and young people at college, have occurred in Britain.

Symptoms include malaise accompanied by fever, severe headache, PHOTOPHOBIA, vomiting, irritability, rigors, drowsiness and neurological disturbances. Neck sti?ness and a positive KERNIG’S SIGN appearing within a few hours of infection are key diagnostic signs. Meningococcal and pneumococcal meningitis may co-exist with SEPTICAEMIA, a much more serious condition in terms of death rate or organ damage and which constitutes a grave emergency demanding rapid treatment.

Diagnosis and treatment are urgent and, if bacterial meningitis is suspected, antibiotic treatment should be started even before laboratory con?rmation of the infection. Analysis of the CEREBROSPINAL FLUID (CSF) by means of a LUMBAR PUNCTURE is an essential step in diagnosis, except in patients for whom the test would be dangerous as they have signs of raised intracranial pressure. The CSF is clear or turbid in viral meningitis, turbid or viscous in tuberculous infection and turbulent or purulent when meningococci or staphylococci are the infective agents. Cell counts and biochemical make-up of the CSF are other diagnostic pointers. Serological tests are done to identify possible syphilitic infection, which is now rare in Britain.

Patients with suspected meningitis should be admitted to hospital quickly. General pracitioners are encouraged to give a dose of intramuscular penicillin before sending the child to hospital. Treatment in hospital is usually with a cephalosporin, such as ceftazidime or ceftriaxone. Once the sensitivity of the organism is known as a result of laboratory studies on CSF and blood, this may be changed to penicillin or, in the case of H. in?uenzae, to amoxicillin. Local infections such as SINUSITIS or middle-ear infection require treatment, and appropriate surgery for skull fractures or meningeal tears should be carried out as necessary. Tuberculous meningitis is treated for at least nine months with anti-tuberculous drugs (see TUBERCULOSIS). If bacterial meningitis causes CONVULSIONS, these can be controlled with diazepam (see TRANQUILLISERS; BENZODIAZEPINES) and ANALGESICS will be required for the severe headache.

Coexisting septicaemia may require full intensive care with close attention to intravenous ?uid and electrolyte balance, control of blood clotting and blood pressure.

Treatment of close contacts such as family, school friends, medical and nursing sta? is recommended if the patient has H. in?uenzae or N. meningitidis: RIFAMPICIN provides e?ective prophylaxis. Contacts of patients with pneumococcal infection do not need preventive treatment. Vaccines for meningococcal meningitis may be given to family members in small epidemics and to any contacts who are especially at risk such as infants, the elderly and immuno-compromised individuals.

The outlook for a patient with bacterial meningitis depends upon age – the young and old are vulnerable; speed of onset – sudden onset worsens the prognosis; and how quickly treatment is started – hence the urgency of diagnosis and admission to hospital. Recent research has shown that children who suffer meningitis in their ?rst year of life are ten times more likely to develop moderate or severe disability by the age of ?ve than contemporaries who have not been infected. (See British Medical Journal, 8 September 2001, page 523.)

Prevention One type of bacterial meningitis, that caused by Haemophilus, has been largely controlled by IMMUNISATION; meningococcal C vaccine has largely prevented this type of the disease in the UK. So far, no vaccine against group B has been developed, but research continues. Information on meningitis can be obtained from the Meningitis Trust and the Meningitis Research Foundation.... meningitis

Pus is a thick, white, yellow or greenish ?uid, found in abscesses (see ABSCESS), ulcers, and on in?amed and discharging surfaces generally. Its colour and consistency are due to the presence of white blood corpuscles, and super?cial cells of granulation tissue or of a mucous membrane which die and are shed o? in consequence of the in?ammatory process (see PHAGOCYTOSIS). Bacteria that normally produce pus are STREPTOCOCCUS, PNEUMOCOCCUS and ESCHERICHIA coli.... pus

n. (pl. cocci) any spherical bacterium. See also gonococcus; meningococcus; Micrococcus; pneumococcus; Staphylococcus; Streptococcus.... coccus

n. any of a group of nonmotile parasitic spherical bacteria that occur in pairs. The group includes the *pneumococcus.... diplococcus

The name given by Sir Alexander Fleming, in 1929, to an antibacterial substance produced by the mould Penicillium notatum. The story of penicillin is one of the most dramatic in the history of medicine, and its introduction into medicine initiated a new era in therapeutics comparable only to the introduction of ANAESTHESIA by Morton and Simpson and of ANTISEPTICS by Pasteur and Lister. The two great advantages of penicillin are that it is active against a large range of bacteria and that, even in large doses, it is non-toxic. Penicillin di?uses well into body tissues and ?uids and is excreted in the urine, but it penetrates poorly into the cerebrospinal ?uid.

Penicillin is a beta-lactam antibiotic, one of a group of drugs that also includes CEPHALOSPORINS. Drugs of this group have a four-part beta-lactam ring in their molecular structure and they act by interfering with the cell-wall growth of mutliplying bacteria.

Among the organisms to which it has been, and often still is, active are: streptococcus, pneumococcus, meningococcus, gonococcus, and the organisms responsible for syphilis and for gas gangrene (for more information on these organisms and the diseases they cause, refer to the separate dictionary entries). Most bacteria of the genus staphylococcus are now resistant because they produce an enzyme called PENICILLINASE that destroys the antibiotic. A particular problem has been the evolution of strains resistant to methicillin – a derivative originally designed to conquer the resistance problem. These bacteria, known as METHICILLINRESISTANT STAPHYLOCOCCUS AUREUS (MRSA), are an increasing problem, especially after major surgery. Some are also resistant to other antibiotics such as vancomycin.

An important side-e?ect of penicillins is hypersensitivity which causes rashes and sometimes ANAPHYLAXIS, which can be fatal.

Forms of penicillin These include the following broad groups: benzylpenicillin and phenoxymethyl-penicillin; penicillinase-resistant penicillins; broad-spectrum penicillins; antipseudomonal penicillins; and mecillinams. BENZYLPENICILLIN is given intramuscularly, and is the form that is used when a rapid action is required. PHENOXYMETHYLPENICILLIN (also called penicillin V) is given by mouth and used in treating such disorders as TONSILLITIS. AMPICILLIN, a broad-spectrum antibiotic, is another of the penicillins derived by semi-synthesis from the penicillin nucleus. It, too, is active when taken by mouth, but its special feature is that it is active against gram-negative (see GRAM’S STAIN) micro-organisms such as E. coli and the salmonellae. It has been superceded by amoxicillin to the extent that prescriptions for ampicillin written by GPs in the UK to be dispensed to children have fallen by 95 per cent in the last ten years. CARBENICILLIN, a semi-synthetic penicillin, this must be given by injection, which may be painful. Its main use is in dealing with infections due to Pseudomonas pyocanea. It is the only penicillin active against this micro-organism which can be better dealt with by certain non-penicillin antibiotics. PIPERACILLIN AND TICARCILLIN are carboxypenicillins used to treat infections caused by Pseudomonas aeruginosa and Proteus spp. FLUCLOXACILLIN, also a semi-synthetic penicillin, is active against penicillin-resistant staphylococci and has the practical advantage of being active when taken by mouth. TEMOCILLIN is another penicillinase-resistant penicillin, e?ective against most gram-negative bacteria. AMOXICILLIN is an oral semi-synthetic penicillin with the same range of action as ampicillin but less likely to cause side-effects. MECILLINAM is of value in the treatment of infections with salmonellae (see FOOD POISONING), including typhoid fever, and with E. coli (see ESCHERICHIA). It is given by injection. There is a derivative, pivmecillinam, which can be taken by mouth. TICARCILLIN is a carboxypenicillin used mainly for serious infections caused by Pseudomonas aeruginosa, though it is also active against some gram-negative bacilli. Ticarcillin is available only in combination with clarulanic acid.... penicillin

Pneumonia is an in?ammation of the lung tissue (see LUNGS) caused by infection. It can occur without underlying lung or general disease, or in patients with an underlying condition that makes them susceptible.

Pneumonia with no predisposing cause – community-acquired pneumonia – is caused most often by Streptococcus pneumoniae (PNEUMOCOCCUS). The other most common causes are viruses, Mycoplasma pneumoniae and Legionella species (Legionnaire’s disease). Another cause, Chlamydia psittaci, may be associated with exposure to perching birds.

In patients with underlying lung disease, such as CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) or BRONCHIECTASIS as in CYSTIC FIBROSIS, other organisms such as Haemophilus in?uenzae, Klebsiella, Escherichia coli and Pseudomonas aeruginosa are more prominent. In patients in hospital with severe underlying disease, pneumonia, often caused by gram-negative bacteria (see GRAM’S STAIN), is commonly the terminal event.

In patients with an immune system suppressed by pregnancy and labour, infection with HIV, CHEMOTHERAPY or immunosuppressive drugs after organ transplantation, a wider range of opportunistic organisms needs to be considered. Some of these organisms such as CYTOMEGALOVIRUS (CMV) or the fungus Pneumocystis carinii rarely cause disease in immunocompetent individuals – those whose body’s immune (defence) system is e?ective.

TUBERCULOSIS is another cause of pneumonia, although the pattern of lung involvement and the more chronic course usually di?erentiate it from other causes of pneumonia.

Symptoms The common symptoms of pneumonia are cough, fever (sometimes with RIGOR), pleuritic chest pain (see PLEURISY) and shortness of breath. SPUTUM may not be present at ?rst but later may be purulent or reddish (rusty).

Examination of the chest may show the typical signs of consolidation of an area of lung. The solid lung in which the alveoli are ?lled with in?ammatory exudate is dull to percussion but transmits sounds better than air-containing lung, giving rise to the signs of bronchial breathing and increased conduction of voice sounds to the stethoscope or palpating hand.

The chest X-ray in pneumonia shows opacities corresponding to the consolidated lung. This may have a lobar distribution ?tting with limitation to one area of the lung, or have a less con?uent scattered distribution in bronchopneumonia. Blood tests usually show a raised white cell (LEUCOCYTES) count. The organism responsible for the pneumonia can often be identi?ed from culture of the sputum or the blood, or from blood tests for the speci?c ANTIBODIES produced in response to the infection.

Treatment The treatment of pneumonia involves appropriate antibiotics together with oxygen, pain relief and management of any complications that may arise. When treatment is started, the causative organism has often not been identi?ed so that the antibiotic choice is made on the basis of the clinical features, prevalent organisms and their sensitivities. In severe cases of community-acquired pneumonia (see above), this will often be a PENICILLIN or one of the CEPHALOSPORINS to cover Strep. pneumoniae together with a macrolide such as ERYTHROMYCIN. Pleuritic pain will need analgesia to allow deep breathing and coughing; oxygen may be needed as judged by the oxygen saturation or blood gas measurement.

Possible complications of pneumonia are local changes such as lung abscess, pleural e?usion or EMPYEMA and general problems such as cardiovascular collapse and abnormalities of kidney or liver function. Appropriate treatment should result in complete resolution of the lung changes but some FIBROSIS in the lung may remain. Pneumonia can be a severe illness in previously ?t people and it may take some months to return to full ?tness.... pneumonia

Ach.

Family: Usneaceae.

Habitat: Common in temperate and alpine Himalayas, as a moss on trees.

English: Lichen.

Unani: Ushnaa.

Action: Moss—used as an expectorant and in the treatment of ulcers.

Key application: German Commission E approves Usnea (dried thallus of U. barbata, U.florida, U. hirta and U. plicata) for mild inflammations of the oral and pharyngeal mucosa.

Usnea preparations are used clinically by North American herbalists for antibacterial action against Grampositive bacteria in local or systemic infections and for antifungal action against Candida albicans. (Expanded Commission E Monographs.)

U. longissima contains 3-4% usnic acid, also barbatic acid and arabitol. Usnic acid and barbatic acid possess marked anti-tubercular activity. Bar- batic acid produces usnic acid, is active against Streptococcus haemolyticus and pneumococcus sp. and inhibits the growth of tubercle bacillus.... usnea longissima

chick embryos injected with the living, attenuated strain (17D) of pantropic virus. Only one injection is required, and immunity persists for many years. Re-inoculation, however, is desirable every ten years. (See YELLOW FEVER.)

Haemophilus vaccine (HiB) This vaccine was introduced in the UK in 1994 to deal with the annual incidence of about 1,500 cases and 100 deaths from haemophilus MENINGITIS, SEPTICAEMIA and EPIGLOTTITIS, mostly in pre-school children. It has been remarkably successful when given as part of the primary vaccination programme at two, three and four months of age – reducing the incidence by over 95 per cent. A few cases still occur, either due to other subgroups of the organism for which the vaccine is not designed, or because of inadequate response by the child, possibly related to interference from the newer forms of pertussis vaccine (see above) given at the same time.

Meningococcal C vaccine Used in the UK from 1998, this has dramatically reduced the incidence of meningitis and septicaemia due to this organism. Used as part of the primary programme in early infancy, it does not protect against other types of meningococci.

Varicella vaccine This vaccine, used to protect against varicella (CHICKENPOX) is used in a number of countries including the United States and Japan. It has not been introduced into the UK, largely because of concerns that use in infancy would result in an upsurge in cases in adult life, when the disease may be more severe.

Pneumococcal vaccine The pneumococcus is responsible for severe and sometimes fatal childhood diseases including meningitis and septicaemia, as well as PNEUMONIA and other respiratory infections. Vaccines are available but do not protect against all strains and are reserved for special situations – such as for patients without a SPLEEN or those who are immunode?cient.... yellow fever vaccine is prepared from

Indian tobacco. Puke weed. Lobelia inflata L. German: Indianischer tabak. French: Tabac indien. Italian: Lobelia. Part used: dried herb collected when part of capsule is inflated.

Constituents: lobeline, resin, wax, gum, lignin, fixed oil.

Action: antasthmatic, antispasmodic, mild sedative and gentle relaxant. Expectorant, diaphoretic, anti- cough. Broncho-dilator containing the alkaloid lobeline. Claimed to destroy pneumococcus. Amphoteric. Emetic. Smoking deterrent (tablets). Respiratory stimulant.

Uses: Broad spectrum therapy: chest, throat, sinuses, middle ear, urinary tract, chronic bronchitis. An effective means of controlling difficult breathing without risk of serious side-effects: croup, whooping cough, pleurisy, etc. For deteriorating asthma where there has been a declining response to routine broncho-dilator treatment. Well tolerated by those allergic to penicillin and for side-effects arising from that therapy. Tetanus (Dr H. Hart, Chi Med Journal). Irritability and hypersensitivity. Nicotine addiction. External. Use of tincture or liquid extract for gouty joints, big toe, etc.

Ear troubles in children: Inject 2 drops Oil Lobelia.

Preparations: Thrice daily.

Dried herb, 50 to 200mg in infusion (BHC Vol 1).

Liquid Extract: 0.2 to 0.6ml (3 to 10 drops).

Tincture Lobelia acid: 1 part to 10 parts cider vinegar; macerate 8 days; decant. Dose: 5 to 10ml (1-2 teaspoons).

Simple Tincture Lobelia BPC (1949), 1:8 in 60 per cent alcohol. Dose, 0.6 to 2ml.

Tablets/capsules. Lobelia compound. Powdered Lobelia BP 60mg; Powdered Gum Ammoniacum BPC 30mg; Powdered extract Squill 2:1, 30mg. Respiratory stimulant for blocked sinuses, catarrh and coughs. Contra-indicated: feeble pulse or nerve response, pregnancy, shock, paralysis. Large doses induce vomiting. ... lobelia