By U. Umbrak. Century University.
It is also the exit point through the base of the skull for all the venous return blood leaving the brain buy 160 mg super p-force amex. The venous structures that carry blood inside the skull form large order super p-force online from canada, curved grooves on the inner walls of the posterior cranial fossa cheap super p-force 160mg without a prescription, which terminate at each jugular foramen. Paranasal Sinuses The paranasal sinuses are hollow, air-filled spaces located within certain bones of the skull (Figure 7. All of the sinuses communicate with the nasal cavity (paranasal = “next to nasal cavity”) and are lined with nasal mucosa. These produce swelling of the mucosa and excess mucus production, which can obstruct the narrow passageways between the sinuses and the nasal cavity, causing your voice to sound different to yourself and others. This blockage can also allow the sinuses to fill with fluid, with the resulting pressure producing pain and discomfort. This irregular space may be divided at the midline into bilateral spaces, or these may be fused into a single sinus space. These are paired and located within the right and left maxillary bones, where they occupy the area just below the orbits. Because their connection to the nasal cavity is located high on their medial wall, they are difficult to drain. It is located within the body of the sphenoid bone, just anterior and inferior to the sella turcica, thus making it the most posterior of the paranasal sinuses. The lateral aspects of the ethmoid bone contain multiple small spaces separated by very thin bony walls. These are located on both sides of the ethmoid bone, between the upper nasal cavity and medial orbit, just behind the superior nasal conchae. The largest are the maxillary sinuses, located in the right and left maxillary bones below the orbits. The most posterior is the sphenoid sinus, located in the body of the sphenoid bone, under the sella turcica. The ethmoid air cells are multiple small spaces located in the right and left sides of the ethmoid bone, between the medial wall of the orbit and lateral wall of the upper nasal cavity. Hyoid Bone The hyoid bone is an independent bone that does not contact any other bone and thus is not part of the skull (Figure 7. It is a small U-shaped bone located in the upper neck near the level of the inferior mandible, with the tips of the “U” pointing posteriorly. The hyoid serves as the base for the tongue above, and is attached to the larynx below and the pharynx posteriorly. The hyoid is held in position by a series of small muscles that attach to it either from above or below. Movements of the hyoid are coordinated with movements of the tongue, larynx, and pharynx during swallowing and speaking. It consists of a sequence of vertebrae (singular = vertebra), each of which is separated and united by an intervertebral disc. The vertebrae are divided into three regions: cervical C1–C7 vertebrae, thoracic T1–T12 vertebrae, and lumbar L1–L5 vertebrae. The vertebral column is curved, with two primary curvatures (thoracic and sacrococcygeal curves) and two secondary curvatures (cervical and lumbar curves). Regions of the Vertebral Column The vertebral column originally develops as a series of 33 vertebrae, but this number is eventually reduced to 24 vertebrae, plus the sacrum and coccyx. The vertebral column is subdivided into five regions, with the vertebrae in each area named for that region and numbered in descending order. In the neck, there are seven cervical vertebrae, each designated with the letter “C” followed by its number. The single sacrum, which is also part of the pelvis, is formed by the fusion of five sacral vertebrae. However, the sacral and coccygeal fusions do not start until age 20 and are not completed until middle age. An interesting anatomical fact is that almost all mammals have seven cervical vertebrae, regardless of body size. This means that there are large variations in the size of cervical vertebrae, ranging from the very small cervical vertebrae of a shrew to the greatly elongated vertebrae in the neck of a giraffe. Curvatures of the Vertebral Column The adult vertebral column does not form a straight line, but instead has four curvatures along its length (see Figure 7. When the load on the spine is increased, by carrying a heavy backpack for example, the curvatures increase in depth (become more curved) to accommodate the extra weight. Primary curves are retained from the original fetal curvature, while secondary curvatures develop after birth. In the adult, this fetal curvature is retained in two regions of the vertebral column as the thoracic curve, which involves the thoracic vertebrae, and the sacrococcygeal curve, formed by the sacrum and coccyx. Each of these is thus called a primary curve because they are retained from the original fetal curvature of the vertebral column. The cervical curve of the neck region develops as the infant begins to hold their head upright when sitting. Disorders associated with the curvature of the spine include kyphosis (an excessive posterior curvature of the thoracic region), lordosis (an excessive anterior curvature of the lumbar region), and scoliosis (an abnormal, lateral curvature, accompanied by twisting of the vertebral column). Kyphosis, also referred to as humpback or hunchback, is an excessive posterior curvature of the thoracic region. This can develop when osteoporosis causes weakening and erosion of the anterior portions of the upper thoracic vertebrae, resulting in their gradual collapse (Figure 7. Lordosis, or swayback, is an excessive anterior curvature of the lumbar region and is most commonly associated with obesity or late pregnancy. The accumulation of body weight in the abdominal region results an anterior shift in the line of gravity that carries the weight of the body. Compensatory curves may also develop in other areas of the vertebral column to help maintain the head positioned over the feet. The cause is usually unknown, but it may result from weakness of the back muscles, defects such as differential growth rates in the right and left sides of the vertebral column, or differences in the length of the lower limbs. Although most individuals do not require treatment, a back brace may be recommended for growing children. If scoliosis is present, an individual will have difficulty in bending directly forward, and the right and left sides of the back will not be level with each other in the bent position. General Structure of a Vertebra Within the different regions of the vertebral column, vertebrae vary in size and shape, but they all follow a similar structural pattern. Because of this, the vertebral bodies progressively increase in size and thickness going down the vertebral column. The large opening between the vertebral arch and body is the vertebral foramen, which contains the spinal cord. In the intact vertebral column, the vertebral foramina of all of the vertebrae align to form the vertebral (spinal) canal, which serves as the bony protection and passageway for the spinal cord down the back. When the vertebrae are aligned together in the vertebral column, notches in the margins of the pedicles of adjacent vertebrae together form an intervertebral foramen, the opening through which a spinal nerve exits from the vertebral column (Figure 7. Each paired transverse process projects laterally and arises from the junction point between the pedicle and lamina. The vertebral spines can easily be felt as a series of bumps just under the skin down the middle of the back.
The absence of spacer 18 bears phyloge- netical significance because it is improbable that this spacer was deleted more than 2 purchase super p-force cheap. This is a general characteristic of strains belonging to the principal genetic groups 2 and 3 buy super p-force 160 mg mastercard, together with the absence of an intact pks 15/1 gene (Marmiesse 2004) discount super p-force 160mg with visa. The presence of intact polyketide synthase genes, active in the synthesis of the specific lipid com- plex of the M. Conversely, the 7 bp frameshift deletion in pks15/1 may be considered as a phylogenetical marker specific for the modern M. The meaning of this identity is under investigation and there is no reason to believe that it is due to convergence. Simi- larly, an endemic clone found in Nunavik (Nguyen 2003) was shown to be related to a clone found to be prevalent in central Europe (Poland and Germany) (Sola et al. Once again, we are trying to analyze how and when such movement of strains took place and whether they are representative of a deeply rooted anthropological structure or from modern outbreaks. These authors also suggest that comparative genomics between two selected genomes that have gone through very different selection pressures (H37Rv and M. Comparative genomics and evolution of tubercle bacilli The wealth of completed genome sequences, the development of microarray tech- nology, and the decreasing cost of sequencing have enabled scientists to thoroughly study the significance of strain to strain variation in bacteria such as Streptococcus agalactiae and to define the “pan-genome” concept (Tettelin 2005). Depending on the population structure of the studied organism and on the levels of lateral gene transfer, the relative part of these two pools may vary signifi- cantly. The core genome contains genes present in all strains, and the dispensable genome contains genes present in two or more strains as well as genes unique to single strains. Given that the number of unique genes is vast, the pan-genome of a bacterial species might be orders of magnitude larger than any single genome (Medini 2005). Figure 2-7 shows the non-randomness of deletions in the 16 clinical isolates that were tested by microarray against the H37Rv genome. Color code (blue, orange, green) is linked to number of deletions (respectively 1, 2 and 3 deletions). The thin red line spans the genomic region of the genome where the number of deletions detected is greater than expected by chance alone. Short-term evolutionary markers and database building There are also ongoing debates about the true status of “M. According to Smith, the computation providing a 3 million-year time frame is not reliable and there is no reason to believe that “M. Conclusion and Perspectives 81 tuberculosis complex than any animal pathogen still to be characterized. However, in order to data-mine these large polymorphism databases better, newer methods of data analysis are needed in order to discover intelligible rules and to eliminate noisy data. A practical consequence of such studies would be a simplification of typing methods, which in turn, would result in a reduction of experimental constraints and an increase in the number of samples processed. In the future, similar websites will add new markers, allowing the performance of combined searches, including country of isolation, country of origin and ethnicity of the patient, multiple geno- typing data, as well as a fine analysis of their geographical distribution. Other challenges may lie in the slow development of efficient methods to characterize the intra-species genetic diversity of the M. However, the increasing human mobility worldwide is expected to blur the picture of the history of spread of the M. Many others remain to be discovered since the sampling is still very small compared to the extent of diversity that is likely to exist. It is quite satisfying to see that the research conducted in the last 12 years is clearly advancing towards a better understanding of the tubercle bacillus and its interaction with the host, the mechanisms of pathogenicity involved, and the co-evolution of the bacterium and its host through time and space. Identification of a Haarlem genotype-specific single nucleotide polymorphism in the mgtC virulence gene of Mycobacterium tuberculosis. Modeling bacterial evolution with comparative- genome-based marker systems: application to Mycobacterium tuberculosis evolution and pathogenesis. Subdivision of Mycobacterium tuberculosis into five variants for epidemiological purposes: methods and nomenclature. Role of the pks15/1 gene in the biosynthesis of phenolglycolipids in the Mycobacterium tuberculosis complex. Evidence that all strains synthesize glycosylated p-hydroxybenzoic methly esters and that strains devoid of phe- nolglycolipids harbor a frameshift mutation in the pks15/1 gene. A back migration from Asia to sub-Saharan Africa is supported by high-resolution analysis of human Y-chromosome haplotypes. Mycobacterium africanum elicits an attenuated T cell response to early secreted antigenic target, 6 kDa, in patients with tuberculosis and their household contacts. A first insight into the genetic diversity of Mycobacterium tuberculosis in Dar es Salaam, Tanzania, assessed by spoli- gotyping. High genetic diversity revealed by variable- number tandem repeat genotyping and analysis of hsp65 gene polymorphism in a large collection of "Mycobacterium canettii" strains indicates that the M. Snapshot of moving and expanding clones of Mycobacterium tuberculosis and their global distribution assessed by spoligotyping in an international study. Identification of vari- able regions in the genomes of tubercle bacilli using bacterial artificial chromosome ar- rays. Genome-wide analysis of synonymous single nucleotide polymorphisms in Mycobacterium tuberculosis complex organisms: resolution of genetic relationships among closely related microbial strains. Single-nucleotide polymorphism-based popu- lation genetic analysis of Mycobacterium tuberculosis strains from 4 geographic sites. Simultaneous detection and strain differentiation of Mycobacterium tuberculosis for diagnosis and epidemiology. Fatty acid biosynthesis in My- cobacterium tuberculosis: lateral gene transfer, adaptive evolution, and gene duplica- tion. Comparison of methods based on different molecular epidemiological markers for typing of Mycobacterium tuberculosis complex strains: interlaboratory study of discriminatory power and reproducibility. Genomic sequence and transcriptional analysis of a 23-kilobase mycobacterial linear plasmid: evidence for hori- zontal transfer and identification of plasmid maintenance systems. A marked difference in pathogenesis and immune response induced by different Mycobacterium tuberculosis genotypes. Origin and primary dispersal of the Mycobacterium tuberculosis Beijing genotype: clues from human phylogeography. Negligible genetic diversity of Mycobacterium tuberculosis host immune system protein targets: evidence of limited selective pressure. A deletion defining a common Asian lineage of Mycobacterium tuberculosis associates with immune subversion. Genetic biodiversity of Mycobacterium tuberculosis complex strains from patients with pulmonary tuberculosis in Cameroon. The senX3-regX3 two-component regulatory system of Mycobacterium tuberculosis is required for virulence. Restriction fragment length polymorphism analysis of Myco- bacterium tuberculosis isolated from countries in the western pacific region. Characterization of Myco- bacterium tuberculosis isolates from patients in Houston, Texas, by spoligotyping. Tuberculosis in the Caribbean: using spacer oligo- nucleotide typing to understand strain origin and transmission. Spoligotype database of Mycobacterium tuberculosis: biogeographic distribution of shared types and epide- miologic and phylogenetic perspectives.
The thick wall is necessary to septum secundum gives rise to a patent foramen ovale (atrial septal pump oxygenated blood at high pressure through the systemic circula- defect) but as long as the two septa still overlap buy discount super p-force 160mg line, there will be no func- tion cheap super p-force 160 mg with mastercard. During ventricular • The wall of the right ventricle is thicker than that of the atria but not systole the free edges of the cusps come into contact and eversion is as thick as that of the left ventricle super p-force 160 mg cheap. During ventricular diastole back-pressure of blood above the cusps forces them to ﬁll and hence close. Times are in msec 22 Thorax The grooves between the four heart chambers represent the sites that right atrium via the coronary sinus. The coronary sinus drains into the offer the least stretch during systole and, for this reason, are where most right atrium to the left of and superior to the opening of the inferior vena of the vessels supplying the heart are situated. The great cardiac vein follows the anterior interventricular branch of the left coronary and then sweeps backwards to the left in the The arterial supply of the heart (Fig. The middle cardiac vein follows the posterior The coronary arteries are responsible for supplying the heart itself with interventricular artery and, along with the small cardiac vein which fol- oxygenated blood. The coronary The coronary arteries are functional end-arteries and hence follow- sinus drains the vast majority of the heart’s venous blood. Under these conditions the increased demand placed on the myocardium cannot be met by the diminished arterial supply. It is situated dilating (angioplasty), or surgically bypassing (coronary artery bypass near the top of the crista terminalis, below the superior vena caval grafting), the arterial stenosis. Ischaemic heart disease is the leading cause of death in the tion pathway can lead to dangerous interruption of heart rhythm. For example, in some people the posterior interven- position of the Purkinje ﬁbres accounts for the almost synchronous tricular branch of the right coronary artery is large and supplies a large contraction of the ventricles. The nerve supply of the heart Similarly, the sinu-atrial node is usually supplied by a nodal branch The heart receives both a sympathetic and a parasympathetic nerve of the right coronary artery but in 30–40% of the population it receives supply so that heart rate can be controlled to demand. Pulmonary trunk They are all covered with Left auricle Posterior pulmonary plexus the mediastinal pleura Sympathetic trunk Phrenic nerve Descending aorta Left ventricle Greater splanchnic nerve Oesophageal plexus on oesophagus Subclavian artery Oesophagus Subclavian vein Trachea Left brachiocephalic Vagus nerve vein Superior vena cava Pulmonary artery Acending aorta Fig. Here the right phrenic enters the caval opening and immediately penetrates the The thoracic sympathetic trunk (Figs 9. It descends in the thorax behind the pleura immediately lateral to costal vein to descend in front of the left lung root onto the pericardium the vertebral bodies and passes under the medial arcuate ligament of the overlying the left ventricle. Note: the phrenic nerves do not pass • The thoracic chain bears a ganglion for each spinal nerve; the ﬁrst beyond the undersurface of the diaphragm. However, they also transmit ﬁbres which are sensory preganglionic ﬁbres from its corresponding spinal nerve and sends to the ﬁbrous pericardium, mediastinal pleura and peritoneum as well back a grey ramus, bearing postganglionic ﬁbres. Upper limb sympathectomy is used for the treatment of hyperhidro- Irritation of the diaphragmatic peritoneum is usually referred to the sis and Raynaud syndrome. Hence, upper abdominal pathology such as a perfor- of part of the thoracic sympathetic chain (usually for two interspaces) ated duodenal ulcer often results in pain felt at the shoulder tip. It ﬁnally reaches the lower oesophagus where it visceraathe heart and great vessels, the lungs and the oesophagus. From this plexus, • Mainly preganglionic ﬁbres from T5–12 form the splanchnic nerves, anterior and posterior vagal trunks descend (carrying ﬁbres from both which pierce the crura of the diaphragm and pass to the coeliac and left and right vagi) on the oesophagus to pass into the abdomen through renal ganglia from which they are relayed as postganglionic ﬁbres to the oesophageal opening in the diaphragm at the level of T10. It is itself crossed here by the left superior intercostal (T5–10), lesser splanchnic (T10–11) and lowest splanchnic (T12). Below, it descends behind the lung root to reach the oesophagus They lie medial to the sympathetic trunk on the bodies of the thoracic where it contributes to the oesophageal plexus mentioned above (see vertebrae and are quite easily visible through the parietal pleura. The cardiac plexus Vagal branches This plexus is for descriptive purposes divided into superﬁcial and deep • The left recurrent laryngeal nerve arises from the left vagus below parts. The nerves of the thorax 25 10 Surface anatomy of the thorax Cervical plexus 2 2 4 4 Cardiac notch of lung Transverse fissure 6 6 Oblique fissure Costodiaphragmatic recess 8 8 10 10 Apex of lower lung Oblique fissure 6 Beginning of transverse fissure 8 Costodiaphragmatic recess Fig. The areas of auscultation for the aortic, pulmonary, mitral and tricuspid valves are indicated by letters 26 Thorax The anterior thorax pleura passes laterally for a small distance at the 4th costal cartilage and Landmarks of the anterior thorax include: descends vertically lateral to the sternal border to the 6th costal cartil- • The angle of Louis (sternal angle): formed by the joint between the age. It is an important landmark as the cross the 8th rib in the mid-clavicular line, the 10th rib in the mid- 2nd costal cartilages articulate on either side and by following this line axillary line and ﬁnally reach the level of the 12th rib posteriorly. The apex and mediastinal border of the right lung follow the pleural • The suprasternal notch: situated in the midline between the medial outline. In mid-inspiration the right lung lower border crosses the 6th ends of the clavicles and above the upper edge of the manubrium. The oblique ﬁssures separate the lungs into upper • The ﬁrst palpable spinous process is that of C7 (vertebra prominens). The • The transverse ﬁssure: is represented by a line drawn horizontally spinous processes of the thoracic vertebrae can be palpated and counted from the 4th costal cartilage to a point where it intersects the oblique in the midline posteriorly. The ﬁssure separates the upper and middle lobes of the right • The scapula is located on the upper posterior chest wall. The heart • The borders of the heart are illustrated by joining the four points Lines of orientation shown (Fig. These are imaginary vertical lines used to describe locations on the • The apex of the left ventricle corresponds to where the apex beat is chest wall. The surface marking for the apex beat is in the 5th intercostal • The mid-clavicular line: a vertical line from the midpoint of the clav- space in the mid-clavicular line. The great vessels •Themid-axillary line: from the midpoint between anterior and poster- • The aortic arch: arches antero-posteriorly behind the manubrium. Palpable bony prominences can be used to identify the location of • The brachiocephalic veins: are formed by the conﬂuence of the inter- important underlying structures. This occurs posterior to the sterno- their corresponding vertebral levels are given: clavicular joints. The position of the nipple is variable The trachea in the female but in the man it is usually in the 4th intercostal space in The trachea commences at the lower border of the cricoid cartilage (C6 the mid-clavicular line. It runs downwards in the midline and ends slightly to the right by bifurcating into the left and right main bronchi. The lines of pleural reﬂection pass behind the sternoclavicu- In mid-inspiration the highest part of the right dome reaches as far as lar joints to meet in the midline at the level of the sternal angle. Surface anatomy of the thorax 27 11 The abdominal wall Serratus anterior Cut edge of external oblique Linea alba Linea semilunaris Cut edge of external oblique Internal oblique Fig. Internal oblique A: above the costal margin Inferior B: above the umbilicus epigastric Transversus abdominis C: above the pubic symphysis artery Peritoneum 28 Abdomen and pelvis (a) External oblique aponeurosis Superficial ring Ilioinguinal nerve Femoral artery and vein in Spermatic cord femoral sheath Femoral canal (b) Testicular artery and Transversus pampiniform plexus of veins Position of deep ring Vas deferens Lymphatics Internal oblique Transversalis fascia Internal spermatic Position of fascia superficial ring Cremasteric fascia and Femoral artery and vein in muscle (striated) femoral sheath Femoral canal External spermatic fascia Fig. The external spermatic fascia has been removed (b) After removal of the external oblique Internal thoracic Anterior cutaneous branches of Musculophrenic intercostal nerves T7 Superior epigastric T10 T12 Lumbar Iliohypogastric (lateral branch) Para-umbilical veins Iliohypogastric anastomose with (anterior cutaneous) epigastric veins Ilioinguinal Fig. The two lower intercostal and four lumbar arteries supply the extraperitoneal fat, and parietal peritoneum. These comprise: external oblique, internal oblique, transversus abdo- • The superﬁcial ring: is not a ring but a triangular-shaped defect in minis, rectus abdominis and pyramidalis (see Muscle index, p. It contains also the super- • Superior: internal oblique arches posteriorly to form the roof of the ior and inferior epigastric vessels and anterior rami of the lower six canal. The linea alba represents the fusion of the nal oblique and transversus into the pectineal line) forms the medial aponeuroses in the midline. The composition of the sheath Contents of the inguinal canal is, however, different above the costal margin and above the pubic • The spermatic cord (or round ligament in the female).
The vaccine master virus is cold-adapted – in other words generic 160mg super p-force with amex, it has been adapted to grow ideally at 25 degrees Celsius discount super p-force 160 mg line, which means that at normal human body temperature buy super p-force overnight, it is at- tenuated. The advantages of a live virus vaccine applied to the nasal mucosa are the devel- opment of local neutralising immunity, the development of a cell-mediated immune response, and a cross-reactive and longer lasting immune response (Couch 1997). Damage to mucosal surfaces, while far less than with wild-type virulent influenza viruses, may lead to susceptibility to secondary infections. Of greater concern for the future is the possibility of genetic reversion – where the mutations causing attenuation change back to their wild-type state – and reassortment with wild-type influenza viruses, resulting in a new strain. However, setting up such a facility takes time and is costly, and most vaccine producers are only now beginning this process. Vaccine Development 131 Reverse genetics allows for specific manipulation of the influenza genome, ex- changing genome segments for those desired (Palase 1997, Palese 2002b). Based on this method, several plasmid-based methods (Neumann 2005) for constructing new viruses for vaccines have been developed, but are not yet in use commercially. These are then detected by the immune system, resulting in both a humoral and cellular immune response (Hilleman 2002). Such vaccines have been shown to be effective in laboratory animals, but data are not available for human studies. Adjuvants have been used in a number of vaccines against other pathogens, and are being investigated for a role in influenza vaccines. The purpose of adjuvants is to increase the immune response to the vaccine, thus allowing either a decrease in an- tigen dose, a greater efficacy, or both. A vaccine using the outer membrane proteins of Neisseria meningitidis as an adjuvant has shown success in early clinical trials (Langley 2005). Only a single round of replication can occur, with termination before the formation of infectious viral particles. Protein expression will result in an immune response, and there is no danger of infection spreading to other cells or people. In persons primed by previous exposure to viruses of the same subtype, anti- body response is similar for the various types of vaccines. However, in persons without such previous exposure (either through vaccination or through natural in- fection), response is poorer in the split and subunit vaccines, where two doses are required. In healthy primed adults, efficacy after one dose ranges from 80-100 %, while in unprimed adults, efficacy enters into this range after two doses. However, the vaccine is 20-80 % effective in preventing death from influenza in persons older than 65 years, with revaccination each year reducing mortality risk more than a single vaccination (Govaert 1994, Gross 1995, Nichol 1994, Partri- arca 1985, Voordouw 2004). Further studies are planned to evaluate the impact of influenza vaccination on acute coronary syn- dromes. Vaccination of caregivers against influenza also reduces the exposure of vulnerable popula- tions to influenza. Studies have been done on effectiveness in terms of health benefits and cost in several healthy populations (Bridges 2000, Langley 2004, Monto 2000, Wilde 1999). They suggest that, while individual health benefits from vaccination certainly exist, as do reductions in days absent from work, vaccinating healthy working adults may not provide cost savings when compared to loss of productivity and days taken off due to illness. Vaccinating health care professionals is rec- ommended, not only because of health benefits and reduced days absent from work, but be- cause it is believed that hospital employees tend to report to work in spite of having an acute febrile illness. Previous studies have shown that vaccinating health care professionals reduces nursing home and hospital-acquired influenza infections (Pachuki 1989, Potter 1997). Side Effects 133 Side Effects Guillain-Barré Syndrome is seen as the most dangerous side effect of influenza vaccines, aside from manifestations of egg allergy. The most frequent side effects are pain, redness, and swelling at the injection site (10-64 %) lasting 1-2 days, and systemic side effects such as headache, fever, mal- aise, and myalgia in about 5 % of vaccinees (Belshe 2005, Musana 2004, Potter 2004). These side effects are largely due to a local immune response, with inter- feron production leading to systemic effects. Local side effects are more common with whole virus vaccines than subunit or split vaccines, and also more common with intradermal vaccination than intramuscular vaccination. Since the inactivated vaccines do not contain live virus, they cannot cause influenza infection – often respiratory illness is incorrectly attributed to influenza vaccination. Live attenuated virus vaccines do contain live virus; however, side effects are rare, with a runny nose, congestion, sore throat, and headache being the most commonly reported symptoms, with occasional abdominal pain, vomiting, and myalgia (Musana 2004). They are not recommended for use in children below the age of 5 years, although a study by Piedra et al. Controversies have arisen around the possibility of exacerbated asthma in children between 18-34 months of age (Bergen 2004, Black 2004, Glezen 2004). L – likelihood of transmission to high risk persons – healthcare workers and care providers can transmit influenza to patients, as can other employees in institutions serving the high risk population groups, as well as people living with individuals at high risk. U – underlying medical conditions such as diabetes mellitus, chronic heart or lung disease, pregnancy, cancer, immunodeficiency, renal disease, organ transplant re- cipients, and others. A – age > 65 years, or between 6-23 months of age Since the risk of influenza rises linearly from the age of 50 years, some promote the vaccination of those aged between 50 and 64 in addition to those above 65 years of age. In a study of health professional attitudes to such a policy in England, both sides were equally divided (Joseph 2005). In the era of a potentially pending pandemic, other groups also have importance for targeting – poultry workers in the Far East are being vaccinated to prevent infection with circulating human influenza strains. This vaccine will not protect against avian influenza strains, but will help prevent dual infection, if infection with avian influ- enza does occur, thereby reducing opportunities for reassortment of two strains in one human host. For the same reason, travelers to areas where avian influenza is present are advised to be vaccinated against human influenza (Beigel 2005). Elderly, non-institutionalized individuals with chronic heart or lung dis- eases, metabolic or renal disease, or immunodeficiencies. Other groups defined on the basis of national data and capacities, such as contacts of high-risk people, pregnant women, healthcare workers and others with key func- tions in society, as well as children aged 6–23 months. Out-of-home caregivers and household contacts of children aged 0-23 months South Africa has the following guidelines (summarised from Schoub 2005), divid- ing the population into 4 groups who may receive the vaccine –! Recommendation for Use 135 o Children with chronic pulmonary or cardiac diseases as well as immunosuppressed children. Category 2 – Contacts of high-risk persons - healthcare workers, caregiv- ers of the elderly and high-risk patients, and persons living with high risk persons. People six months of age and older with chronic illnesses requiring regular medical follow-up or hospitalisation in the previous year! People six months of age and older with chronic illnesses of the pulmonary or circulatory systems (except asthma)! Children and teenagers aged six months to 18 years on long-term aspirin therapy (because aspirin treatment puts them at risk of Reye’s syndrome if they develop a fever)! Canada, al- though having similar recommendations for priority groups, actively encourages vaccination of everyone above the age of 6 months (Orr 2004).