EPI 390 Lecture 24Outline of Last Lecture I. Obesity ClassificationsII. Obesity Trends in the USIII. Measuring ObesityIV. NHANESV. Stratifications for ObesityOutline of Current Lecture I. Definition and Origin of poliomyelitisII. Transmission of the polio virus and ContractibilityIII. Serotypes and their SymptomsIV. PPS in Post-Polio SurvivorsV. Complications of PolioVI. Prevention and Treatment StrategiesCurrent LectureI. Definition and Origin of poliomyelitisa. Infantile paralysisb. From the Greek: i. polios = grey (spinal cord)ii. itis = inflammation c. Polio is an acute, infectious, contagious viral disease that can affect the spinal cord and cause muscle weakness and potential paralysis.II. Transmission of the polio virus and Contractibilitya. Fecal-Oral i. From hands contaminated with the stool of an infected person (direct transmission).ii. From food/water contaminated with fecal matter (could be from improper handling by contaminated hands).b. Oral-Oral – This is a less frequent mode of transmission.i. Transmission by an infected individual’s saliva.c. Infants and young children are most prone to infection, especially under filthy, unhygienic conditions.i. Paralysis is more common/more severe when contracted in older individuals.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.III. Serotypes and their Symptomsa. Abortive poliomyelitis i. Experience minor flu-like symptoms, upper respiratory infection, nausea, fever, sore throat, general fatigue, etc.b. Non-paralytic poliomyelitis i. Associated with aseptic meningitis ii. 1-5% of cases have neurological symptoms such as neck stiffness, headache, lethargy, and light sensitivity c. Paralytic poliomyelitis (0.1%-~2% of cases) i. A severe form of poliomyelitis with muscle paralysis (site-specific types: spinal - 79%, bulbospinal - 19%, bulbar - 2%)d. Illness durationi. Acute Phase < 2 weeks ii. Longer-term - If there is significant nerve involvement, muscle paralysis could last for life.IV. PPS in Post-Polio Survivorsa. PPS affects polio survivors (perhaps up to 50%) approximately 10-40 years after initial the polio infection (w/ periodic new signs and symptoms).i. This condition is generally not life threatening but there is no known cause or effective treatment.ii. PPS is characterized by progressive muscle weakening and pain, fatigue with minimal physical activity, muscular atrophy, joint pain (often leading to skeletal deformities), complications in breathing (i.e. sleep apnea) or swallowing.b. Major risk factors i. Severity of initial infection: the disease is more severe in the initial infection ii. Age of onset of initial infection: in adolescents or adults iii. Recovery: greater chance of recovery after acute infection. iv. Physical activity: Better health of skeletomuscular structure, unless done to the point of exhaustion/fatigue.v. Gender: females are more prone.c. Competing theories i. Theory 1: The most widely accepted theory holds that there is (continued?) degeneration or damage to nerve cells, especially of motor neurons in the spinal cord. This disrupts the electrical impulses between the brain and muscles.ii. Theory 2: Initial illness prompts an autoimmune response, causing the body’s immune system to attack or ‘recognize’ normal nerve cells as foreign entities.V. Complications of Polioa. Damage from falls - muscle weakness can lead to broken bones b. Malnutrition, dehydration, (aspiration) pneumonia, if nerves (i.e., cranial) innervating muscles responsible for chewing and swallowing are involved - bulbarpolio.c. Acute respiratory failure - weakening of muscles involved with respiration, fluid in lungs may accumulate, sharp drop in blood O2 concentration in the blood and tissues, requiring ventilation therapy.d. Osteoporosis - prolonged inactivity/immobility (< BMD)VI. Prevention and Treatment Strategiesa. Iron lung machinesi. At height of outbreak (1940s-1950s), the standard treatment was to placethose with paralysis of respiratory muscles in an “iron lung’ machine. 1. Due to confinement, the limbs were immobilized. ii. Ventilators are now used to perform this function. b. Home treatment for paralytic polio was not possible for most at the time (thoughit is today). c. At present, there is no cure for polio and ‘treatment’ involves supportive care. Preventative vaccines have been made available, though.i. Salk vaccine (inactivated) - the 1st vaccine to be approved (1955) 1. It has been given since 2000 (via injection) ii. Sabin vaccine (attenuated) - approved in 1963 1. It was given until late 1990s (orally) iii. 1954 Salk Polio Vaccine Trials - One of the largest public health initiatives ever undertaken (2 different study designs were used) 1. Polio epidemics struck US throughout 20th century, especially mid-century and were responsible for ~ 6% of all deaths among 5-9 year