By G. Varek. Columbia Union College. 2019.
Clearly buy ondansetron 4 mg with visa, antibiotics have been shown to be able to prevent bacteraemia following dental extraction cheap ondansetron 8mg on line. Fur- thermore discount ondansetron 4mg visa, proper laboratory facilities and clinical acumen are re- quired to reduce the occurrence of this complication of rheumatic heart disease discount 4mg ondansetron visa. American Heart Association Committee on the Prevention of Rheumatic Fever buy ondansetron 8 mg without prescription, Endocarditis and Kawasaki Disease. Recommendations for prevention, diagnosis and treatment of infective endocarditis. New criteria for diagnosis of infective endocarditis: utilization of speciﬁc echocardiographic ﬁndings. Prospects for a streptococcal vaccine Early attempts at human immunization Attempts to prevent group A streptococcal infections by immuniza- tion date back to the early years of the twentieth century (1–4). Efforts to develop a vaccine against group A strep- tococci were placed on a ﬁrmer scientiﬁc footing with the recognition that the principal virulence factor of group A streptococci was M- protein, a streptococcal wall constituent (5), and that opsonic anti- bodies to M-protein protected animals from lethal challenge. Such antibodies persisted for many years in humans (6) and appeared to be the basis of acquired type-speciﬁc immunity (7). Nevertheless, at- tempts to develop a safe and effective M-protein vaccine encountered considerable difﬁculties because of the multiplicity of M-protein sero- types (and genotypes), the toxicity of early M-protein preparations, and the immunological cross-reactivity between M-protein and hu- man tissues, including heart tissue (8) and synovium (9). M-protein vaccines in the era of molecular biology Although our knowledge of the structure and function of M-protein has advanced considerably in recent years (11–15), M-protein pre- parations used in vaccines are still not free of epitopes that elicit immunological cross-reactivity with other human tissues. Antibodies against M-proteins, for example, cross-react with alpha-helical human proteins, such as tropomyosin, myosin and vimentin. Primary struc- ture data have revealed that M-proteins of rheumatogenic streptococ- cal serotypes, such as serotypes 5, 6, 18 and 19, share similar sequences within their B-repeats, and it is likely that such sequences are responsible for eliciting antibodies that cross-react with epitopes in the heart, brain and joints (16). Most of the cross-reactive M- protein epitopes appear to be located in the B-repeats, the A-B ﬂanking regions, or the B-C ﬂanking regions, all of which are some distance from the type-speciﬁc N-terminal epitopes (16–18). In contrast, antibodies raised against synthetic N-terminal peptides that correspond to the hypervariable portions of M-protein serotypes 5, 6 and 24 are opsonic, but do not cross-react with human tissue (17– 19). Further studies have shown that peptide fragments of M- 106 proteins, incorporated into multivalent constructs as hybrid proteins or as individual peptides linked in tandem to unrelated carrier pro- teins, elicited opsonic and mouse-protective antibodies against mul- tiple serotypes, but did not evoke heart-reactive antibodies (20, 21). These estimates were based on sero- type distribution data from economically developed western coun- tries, and such a vaccine might need to be reconstituted, based on prevalent local strains. Current studies are directed toward utilizing commensal gram-positive bacteria as vaccine vectors (22–23). One of these is C5a peptidase, an enzyme that cleaves the human chemotactic factor, C5a, and thus interferes with the inﬂux of polymorphonuclear neutrophils at the sites of inﬂammation (24). Intranasal immunization of mice with a defective form of the streptococcal C5a peptidase reduced the colo- nizing potential of several different streptococcal M-serotypes (25). A second potential vaccine target is streptococcal pyrogenic exotoxin B (SpeB), a cysteine protease that is present in virtually all group A streptococci. Mice passively or actively immunized with the cysteine protease lived longer than non-immunized animals after infection with group A streptococci (26). Epidemiological considerations Once a safe and effective streptococcal vaccine is available many practical issues would need to be addressed. Other issues, such as cost, route of administration, number and frequency of required doses, potential side-effects, stability of the material under ﬁeld conditions, and dura- bility of immunity, would all inﬂuence the usefulness of any vaccine. The most promising approaches are M-protein-based, including those using multivalent type-speciﬁc vaccines, and those directed at non-type-speciﬁc, highly conserved portions of the molecule. Success in developing vaccines may be achieved in the next 5–10 years, but this success would have to contend with important questions about the safest, most economical and most efﬁcacious way in which to employ them, as well as their cost-effectiveness in a variety of epidemilogic and socio-economic conditions. A review of past attempts and present concepts of producing streptococcal immunity in humans. Intravenous vaccination with hemolytic streptococci: its inﬂuence on the incidence of rheumatic fever in children. Persistence of type-speciﬁc antibodies in man following infection with group A streptococci. Epitopes of group A streptococcal M protein shared with antigens of articular cartilage and synovium. Rheumatic fever: a model for the pathological consequences of microbial-host mimicry. Streptococcal M protein: alpha-helical coiled-coil structure and arrangement on the cell surface. Alternate complement pathway activation by group A streptococci: role of M-protein. Inhibition of alternative complement pathway opsonization by group A streptococcal M protein. Streptococcal infections: clinical aspects, microbiology, and molecular pathogenesis.
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 proven 8 mg ondansetron. It is a small U-shaped bone located in the upper neck near the level of the inferior mandible proven ondansetron 4mg, with the tips of the “U” pointing posteriorly buy cheap ondansetron 4mg on line. The hyoid serves as the base for the tongue above generic ondansetron 8 mg on-line, and is attached to the larynx below and the pharynx posteriorly buy generic ondansetron 8mg on-line. 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.
Laryngoscopy can be further With the apnea that occurs at induction of anesthe- impeded by the presence of large breasts order ondansetron 4mg with visa. Gastric motility is decreased and “oxygen reserve” during apnea order ondansetron 8 mg on-line, has decreased by gastric secretions increase order 8mg ondansetron with visa. This discount 4 mg ondansetron visa, combined with a 20% due to upward displacement of the dia- decrease in the integrity of the gastroesophageal phragm discount ondansetron 8mg fast delivery. In fact, airway complications (dif- Adequate ventilation must be maintained during ﬁcult intubation, aspiration) are the most common anesthesia. The concomitant rightward shift in Labour Analgesia the oxyhemoglobin dissociation curve allows increased fetal trans- There are many methods of relieving the pain and stress of labour. This is signiﬁcant for two rea- oxide), intravenous (opioids) or regional (epidural) are associated sons. Firstly, the normal signs of hypovolemia may not be seen un- with side effects and risks to both fetus and mother. This extends to include sacral segments (S2-4) during Due to the increasing uterine size, aortocaval compression (obstruc- the second stage. Thus, the principle of epidural analgesia is to ad- tion of the inferior vena cava and aorta) becomes relevant in the minister local anesthetics (with or without opioids) into the third trimester. When the pregnant patient is in the supine posi- epidural space to block the aforementioned spinal segments. The patient remains alert and coopera- lateral tilt, usually achieved with a pillow under the woman’s right tive. In the absence of complications, there are no ill effects on the hip, is an important positioning maneuver. Epidural analgesia can be therapeutic for patients with pre- eclampsia or cardiac disease where a high catecholamine state is detrimental. Finally, the level and intensity of an epidural block can be extended to provide anesthesia for operative delivery (Cae- sarian section). As well as blocking sensory ﬁbres, local anesthetics in the epidural space interrupt transmission along sympathetic and motor neu- rons. The hypotension associated with sympathetic blockade can be minimized by a one litre bolus of crystalloid prior to institution of the block, slow titration of the local anesthetic, the use of lower concentrations of local anesthetic and vigilant guarding against aor- tocaval compression. Whether it also leads to an increased incidence of op- nant patient are those related to the respiratory system. The degree of motor block the risks of aspiration and failed intubation, and the depressant ef- can be minimized by using lower concentrations of local anesthet- fects of anesthetic agents on the fetus, general anesthesia is ics along with opioid adjunct. The use of a local anesthetic infusion avoided (where possible) in the parturient undergoing Caesarian (as opposed to boluses or “top-ups”) may give a more consistent section. Regional anesthesia is the preferred technique and can be level of block, lower total dose of local anesthetic, less motor block provided by administering spinal anesthesia or by extending the and less risk of drug toxicity. These include coagulopathy, hypovolemia, infection, certain cardio- vascular conditions and patient refusal. The second situation where a regional technique may not be appro- priate is in the setting of severe fetal distress. In this setting, gen- eral anesthesia almost always allows the most rapid delivery of the compromised fetus. If the fetal heart rate is very low and the mater- nal airway appears favourable, then general anesthesia will be quickly induced. General anesthesia in the parturient is unique in several respects which reﬂects the many physiologic changes in this patient popula- tion. Other important considerations are the risk of aspiration, rapid desaturation and the need to avoid both neonatal depression and uterine atony. Generally speaking, no opioids are administered until delivery of the infant in order to avoid unnecessary neonatal depression. The patient is maintained on a 50% mixture of nitrous oxide and oxygen, and a low dose of volatile agent. The vola- tile anesthetics, in higher doses, can decrease uterine tone, which can lead to increased blood loss. The parturient must be extubated when fully awake so that intact laryngeal re- ﬂexes will protect against aspiration. Post-operative pain management in the post-Caesarian section patient is usually straightforward as the lower abdominal incision is relatively well-tolerated. In the instance where intrathecal morphine was administered to the patient undergoing spinal anesthesia, up to 24 hours of pain relief can be achieved. This means that the “snifﬁng position” is often best achieved with the head in the neutral position, The pediatric airway is relatively more prone to without the use of a pillow.
The major noncarditic manifestations occur in varying combinations ondansetron 8 mg discount, with or without carditis buy 8 mg ondansetron visa, during the evolution of the disease generic ondansetron 4 mg fast delivery. The presence of noncarditic manifestations facilitates the detec- tion of rheumatic carditis and their identiﬁcation is particularly important in recurrences of disease buy ondansetron 4 mg free shipping, when the diagnosis of carditis is difﬁcult purchase ondansetron 4mg visa. Diagnosis of rheumatic carditis Although the endocardium, myocardium and pericardium are all affected to varying degrees, rheumatic carditis is almost always asso- ciated with a murmur of valvulitis (Table 4. Accordingly, myocardi- tis and pericarditis, by themselves, should not be labeled rheumatic in origin, when not associated with a murmur and other etiologies must be considered. Simultaneous demonstration of valvular involvement generally considered essential. The strict application of diagnostic criteria is mandatory to demonstrate pathological valvular regurgitation. Currently, data do not allow subclinical valvular regurgitation detected by echocardiography to be included in the Jones criteria, as evidence of a major manifestation of carditis. Myocarditis Myocarditis (alone) in the absence of valvulitis is unlikely to be of rheumatic origin and by itself should not be used as a basis for such a diagnosis. If previous clinical ﬁndings are known, they can be compared with current data — myocardial involvement is likely to result in a sudden cardiac enlargement that will be detectable radiographically. At times, however, the friction rub can mask the mitral regurgitation murmur, which becomes evident only after the pericarditis subsides. Since isolated pericarditis is not good evidence of rheumatic carditis without supporting evidence of a valvular regurgitant murmur, it may be helpful to have Doppler echocardiography available in such circumstances to look for signs of mitral regurgitation. Echocardiography could also corroborate the mild-to-moderate pericardial effusion likely to be associated with pericarditis; large effusions and tamponade are rare (18). Patients with this form of pericarditis are usually treated as cases of severe carditis. Noncardiac manifes- tations may be the best guide for a diagnosis of rheumatic carditis. Arthritis is often the only major manifestation in adolescents, as well as in adults, where carditis and chorea become less common in older age groups. Joint pain without objective ﬁndings does not qualify as a major disease manifestation because of its nonspeciﬁcity. Inﬂamed joints are characteristically warm, red and swollen, and an aspirated sample of synovial ﬂuid may reveal a high -3 -3 average leukocyte count (29000mm , range 2000–96000mm ) (21). Tenderness in rheumatic arthritis may be out of proportion to the objective ﬁndings and severe enough to result in excruciating pain on touch. The term “migratory” reﬂects the sequential involvement of joints, with each completing a cycle of inﬂammation and resolution, so that some joint inﬂammation may be resolving while others are beginning. Frequently, several joints may be affected simulta- neously, or the arthritis may be additive rather than migratory. In- ﬂammation in a particular joint usually resolves within two weeks and the entire bout of polyarthritis in about a month if untreated. Polyarthritis and Sydenham’s chorea virtually never occur simultaneously due to the disparity in the la- tency period following the antecedent streptococcal infection. One study, for example, found severe cardiac involvement in 10% of those with arthritis, 33% of those with arthralgia, and 50% of those with no joint symptoms (19). Following a streptococcal infec- tion, some patients develop arthropathy that differs from acute rheu- matic arthritis. Gonococcal arthritis can present a problem because it occurs frequently in adolescents who do not have localized gonococcal disease, and whose blood and joint ﬂuid cultures are negative in microbiological tests. The diagnosis can be helped by an epidemiological history and characteristic gonococcal skin lesions (if present), in addition to gonococcal cultures of urethra, cervix, rectum and pharynx. A diagnosis of Lyme disease should take into account the season of the year, geographical locale, and history of tick bites. The diagnosis can be conﬁrmed by serological studies and the patient response to anti- microbial therapy. Viremias, some of which are associated with immune complex forma- tion, may also mimic rheumatic polyarthritis. Rheumatological manifestations of other immune complex diseases such as serum sickness may be confusing, particularly when they occur in a patient who has recently received antibiotics for an upper respiratory tract infection. In juvenile rheumatoid arthritis certain associated ﬁndings, such as rash, lymphadenopathy and splenomegaly, may suggest the diagnosis. At times, the only way to arrive at a deﬁnite diagnosis is to observe the clinical course. Arthritis heals completely, unlike carditis, and leaves no pathological or functional residua. This rare condition is not a true synovitis, but rather is a periarticular ﬁbrosis of the metacar- pophalangeal joints. Sydenham’s chorea Chorea occurs primarily in children and is rare after the age of 20 years. The reasons for the variation were not apparent, but might be related to differences in susceptibil- ity to chorea in the host population, or to differences in case-ﬁnding methods. It is unknown whether particular strains of group A strepto- cocci vary in their propensity to elicit chorea.
Characteristics of chemical transmission • Chemical transmission is unidirectional • Chemical transmission is graded effective 4 mg ondansetron, with the amount of transmission chemical released dependent on the frequency of stimulation of the presynaptic neuron buy 8mg ondansetron free shipping. The muscle cells are the real specialists having contractile proteins present in skeletal cheap ondansetron 8mg with visa, cardiac and smooth muscle cells order 4mg ondansetron overnight delivery. They are capable of shortening and developing tension that enables them to produce movement and do work cheap 4 mg ondansetron mastercard. Skeletal muscle is the largest body tissue accounting for almost 40% of the body weight in men and 32% in women. Muscles are categorized as striated and non-striated/ smooth muscles and also typed as voluntary and involuntary subject to innervations by somatic or autonomic nerves and whether subject to voluntary or not subject to voluntary control. Microstructure of Skeletal muscle Skeletal muscles contract in response to signals from its innervating somatic nerve that releases acetylcholine at its terminals that starts the muscle action potentials. A muscle fiber is fairly large, elongated and cylindrical shaped ranging from 10-100 μm in diameter and up to 2. A muscle is made up of a number of muscle fibers arranged parallel to each other and wrapped by connective tissue as a bundle. A single muscle cell is multi-nucleatd with abundant number of mitochondria to meet its high energy demands. Each cell has numerous contractile myofibrils, constituting about 80% of volume of muscle fibers extending the entire length. Each myofibril consists of the 81 thick myosin filaments (12-18 nm diameter) and thin actin filaments (1. A relaxed muscle shows alternating dark bands (A band) and light bands (I band) due to slight overlapping of thick and thin filaments under the microscope. In the middle of each I band is a dense vertical Z line, actually a flattened disc like cytoskeletal protein that connects the thin actin filaments of 2 adjoining sarcomers. Excitation - Contraction Coupling refers to the sequence of events linking muscle excitation to mechanical contraction. At neuro-muscular junction of skeletal muscle neurotransmitter Ach released from innervating motor neuron results in muscle contraction. When an action potential travels down the T- tubules, the local depolarization activates the voltage-gated dihydropyridine receptors. Tropomyosin-troponin complex is repositioned; ++ the released Ca binds with troponin C exposing the binding sites on the actin molecule so that they can attach with the myosin cross bridges at their specific sites. This stiffness of death is a generalized locking in place of skeletal muscle beginning 3-4 hours after death and completed in about 12 hours. The onset of the resultant contraction response lags behind the action potential because the excitation- contraction coupling process must occur before cross bridges activity begins. As a matter of fact, the action potential ends before the contraction mechanism even becomes operational. The contraction time lasts about 50 msec, although it varies with 84 the type of muscle fiber. The relaxation time lasts slightly longer than contraction time, another 50 msec or more. When an action potential depolarizes the presynaptic membrane, the transmitter cannot activate enough receptors to evoke an action potential in the muscle fiber. Autoimmune thymitis Enlarged thymus may also be another cause of myasthenia gravis. Autoimmune thymitis associated with the release of a hormone called thymopoietin (or thymin). Within minutes, some of these paralyzed persons can begin to function normally Muscle twitch Contraction of a whole muscle can be of varying strength. A twitch, which is too short and too weak for any use in the body, is produced as a result of a single action potential in a muscle fiber. Muscle fibers are arranged into a whole muscle and function with cooperation producing contraction of varying grades of strength stronger than a twitch. The number of muscle fibers contracting within a muscle The tension developed by each contracting fiber. Motor unit: Each whole muscle is innervated by a number of different motor neurons. One motor neuron innervates a number of muscle fibers, but each muscle fiber is supplied by only one motor neuron. Muscles producing very precise, delicate movement such as extraocular eye muscles and the hand digit muscles contain a few dozen muscle fibers. Muscles designed for powerful, coarsely controlled movement such as those of legs, a single motor unit may have 1500-2000 muscle fibers. This tension generated by the contractile elements is transmitted to the bone via the connective tissue and tendon before the bone can be moved. Intracellular components of the muscle such as the elastic fiber proteins and connective tissue collagen fibers have a certain degree of passive elasticity.
The wastes including garbage from the kitchen and the cafeteria are given to pigs that scavenge around these facilities purchase 8mg ondansetron overnight delivery. The sewage drains to underground sewers but there is frequent blockage that leads at times to overflow trusted 4mg ondansetron. This is not given much attention by the school management as they consider it to be normal to kitchens and cafeterias buy 8mg ondansetron fast delivery. The clinic head reports that mass diarrhea complaints are commonly observed but are usually not serious order 4mg ondansetron visa. In addition buy ondansetron 8 mg without prescription, the head of the clinic believes that giving proper care to the sick is easier and better than wasting time assessing the cafeteria. Do you think training of food handlers can address any problem related to food hygiene in the cafeteria? Do you believe medical certification of food handlers that will be renewed every 6 months plays an important role in reducing food borne diseases? Applied to the food industry, sanitation is “the creation and maintenance of hygienic and healthful conditions”. Sanitation is the application of a science: to provide wholesome food handled in a clean environment by healthy food handlers, to prevent contamination with microorganisms or toxic chemicals that cause food borne illness, and to minimize the proliferation of food spoilage microorganisms. However, unsanitary operations frequently result from a lack of understanding of the principles of sanitation and the benefits that effective sanitation will provide (7). Because of lack of awareness on issues of sanitation food borne diseases are among the major health problems in Ethiopia. Food borne diseases can also be caused by a variety of chemicals that may lead to illness and deaths of people who may have consume foods contaminated by these chemicals. Food sanitation is an applied sanitary science related to the production, harvesting, storage, distribution/ transport, processing, preparation, and handling of food. Sanitation applications refer to hygienic practices designed to maintain a clean and wholesome environment for food production, preparation, and storage. This applied science relates to the physical, chemical, and biological factors that constitute the environment. The basic principles for food sanitation to control food borne illnesses and outbreaks can be summarized to three essential activities: ¾ Prevention of contamination of the food from microorganisms, their toxins or other chemicals of health hazard. Biological agents in food that are of concern to public health include pathogenic strains of bacteria, viruses, parasites, helminthes, protozoa, algae, and certain toxic products they may produce. An example of path ways to food for selected chemical contaminants of food (19) Food can be contaminated in the chain of its production and distribution, i. Disposing of human waste in unsanitary manner may contaminate the food with pathogenic organisms, similarly different chemicals, such as pesticides, herbicides, and fungicides may be deposited on to and absorbed by various crops and vegetables (6,19). Harvest: Harvesting food into contaminated receptacles can spread causative agents of disease, or may also lead to its contamination by poisonous chemicals if the receptacle was used to store such chemicals (6). Transporting: During transportation, food can be contaminated by people, storage containers and so on (6). Processing and storage: Food is liable for contamination during its processing and storage if stringent sanitation measures are not in place. Food preparation and consumption areas: Restaurants cafeterias, mess halls, kitchens, bars, dining rooms, service tables, and utensils etc. In principle the same flow scheme applies to both the food industry and to locally produced foods for private consumption (19) Hazards: Production of • Nutrients Raw Materials • Natural toxins • Microbial toxins • Environmental contaminants Food Processing Hazards: • Reaction products • Contaminants • Additives Storage and Transport Hazards: • Chemical contamination • Microbial contamination Hazards: Food Consumption • Chemical contamination • Microbial contamination Risks: • Intoxication by chemical contaminates Food Preparation • Food-borne infections • Food poisoning Fig. Major contamination sources are (7, 19,4): ¾ Water: water serves as a cleaning medium during sanitation operation and is an ingredient added in the formulation of various foods. If a safe water supply is not used it then becomes a source of contamination of the food (chemical or biological agents). Examples are microorganisms causing typhoid and paratyphoid fevers, dysentery, and infectious hepatitis. If raw sewage drains or flows into potable water lines, wells, rivers, lakes, and ocean bays the water and living organisms such as seafood are contaminated. This contamination can result from unclean air surrounding the food or from contamination through improper sanitary practices. The hands, hair, nose, and mouth harbor microorganisms that can be transferred to food during processing, packaging, preparation, and service by touching, breathing, coughing, or sneezing. This is because the human body is warm; microorganisms proliferate rapidly, especially in the absence of good hygienic practices. The amounts and types of these agents vary with place and method of harvesting, type of food ingredient, processing technique, 93 and handling. There could be hazards connected to these ingredients if there is lack of awareness of the incoming individual ingredients. These pests transfer contaminants to food through their waste products; mouth feet, and other body parts; and during regurgitation onto clean food. Like flies and cockroaches, they transfer filth from garbage dumps and sewers to food or food processing and food service areas. Meat of animals can get contaminated during slaughtering, cutting, processing, storage, and distribution.