MPH 6402 Environmental & Public Health
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phealth1.docM.Ingold
MPH 6402 Environmental & Public Health
1)PUBLIC HEALTH
Definitions:a) Public health is what we, as a society do collectively to assure the conditions in which
people can remain healthy.
b) Public health is the science and art of:
• Preventing disease by some of the following methods:
- USDA meat Inspection
- Immunizations
- Mosquito spraying
- Early testing programs (AIDS, Hypertension etc.)
- RDA for foods
- Education (ie: Sex to prevent STD transmission)
• Prolonging Life by:
- Health benefits
- Seatbelt, Gun, Helmet, Speeding & DWI Laws
- Drinking age laws
• Promoting Health & Efficiency through organization in the community that:
a. Implement sanitation, control of communicable diseases, education of personal hygiene
- EPA (air/water/sewage/toxic wastes/landfills, etc)
- CDC for communicable diseases
- Local health departments for prenatal care etc
b. Organization of medical/nursing services for early diagnosis &
preventative Tx of disease.
- Local health departments do this
c. Develop social machinery to ensure everyone a standard of living
adequate for the maintenance of health.
- Food stamps, social security etc.
2) IMMUNIZATIONS
A. VIDEO ON POLIO:
1916• Polio outbreak in 1916 & declined until 1921.
1921• FDR gets polio in 1921
• Season related; worse in late summer towards Fall
• Called Infantile Paralysis because mostly affected kids
1931• Sabin middle east; few kids get polio
• Virus through mouth & intestinal waste
• Virus seen on electron microscope
• Sister Kennedy introduces Physiotherapy & hotpack therapy
1935• Colmer vaccine on monkeys has disastrous results on kids
1938• O’Conner starts March of dimes
1950’s• Polio is on the rise (95% kids not paralyzed; 5% are)
1951/52• Salk perfects KILLED VIRUS (3 types)
• Sabin continues work on “LIVE VIRUS”
1955• Salk does field trial for KILLED VIRUS. Although 80-90% success there is bad batch and 204 kids affected by the vaccine.
Late 50• Sabin introduces Oral Polio virus in Russia with huge success (77 million vaccinated)
1961• OPV endorsed in USA. Sabin becomes famous; Salk disappears into history
2000• The trend is to try to vaccinate every child in the world to eradicate polio
REPORT ON POLIO VIDEO
Max Ingold
14/09/2000
The video was most interesting & as noted by Professor Aberrant, very few of us remember the effects that Polio wrought on the American public. After viewing the video some thoughts came to mind.
1) First & foremost it was amazing to see how the “People” of the country rallied around & provided the funding for Polio research. Also the fear factor that kept people segregated was quite an eye opener.
2) If the government was supposed to be responsible for the well being of it’s citizen’s why was there no funding for research? Why did all the money come form the people?
3) Dr. Salk’s country wide 1.8 million field trial was a real eye opener. Although, they had a control group, was there any mechanism to follow the patients through in later life to determine if there were any possible side effects to the vaccine? It was surprising how, Dr. Salk really told no one about the field trial until his presentation at a symposium where everyone was taken by surprise.
I think we have some lessons to learn form this video:
1) People make mistakes. Salk jumped the gun. with his field trial. Can we blame him? Yes & no. He obviously helped many children. An error can happen anywhere; I am sure that due to the bad batches improved quality control have been instituted in the pharmaceutical companies.
2) A society will come together sooner or later & tackle what may appear to be an insurmountable problem leaving behind the negative attributes such as segregation and racism hopefully.
I wonder how far our society will go to try and eradicate every viral/bacterial disease & what the cost will be to society. I have a good friend who is a vaccine researcher, who has told me that they are working on a variety of vaccines. If their work proves successful they could introduce another 15-20 vaccines to be given to young infants. We already routinely give 20-22 vaccines to children in their first 4-5 years of life.
Have we as a species become so susceptible to every little environmental influence that we can no longer protect ourselves by our own natural abilities. One of my biggest concerns is that many vaccines contain carcinogenic & neurotoxic substances. We are injecting these into infants at a point in their life where there nervous system is not mature yet. What are all these products doing to the nervous system & are there any long term “double blind” studies that actually look at this aspect of vaccination.
ANTIBODIES/ANTIGENES
1)CLASSES OF ANTIBODIES:
General info:
• Antibodies are formed in response to foreign material (antigenes) that enter the body.
• There is a very specific Antigene/antibody response (specificity)
• Antigenes produce immunoglobins (AKA antibodies); this is know as Immunogenicity
• There are 5 classes of Immunoglobins that are chemically different
ANTIBODY / DESCRIPTIONIgG / • This is the most common immunoglobin (Ig) in the body; around 75% of all Ig’s & found in the blood & interstitium
It is the only one capable of crossing the placenta (providing passive immunity) that lasts about 6 months. Therefore
will find [ ] in newborns
One of only 2 Ig from mother that activates compliments
• This Ig is responsible for opsonization (easier for WBC to phagocytize bacteria) & the best Ig against capsulated bacterium
• It is only active against polysaccaride antigens & good fighter against bacteria & viruses
IgM / • This is the largest of Antibody (pentamere, 5 times size of IgG with 10 active sites) & therefore cannot cross the placenta.
• It makes up about 9% of Ig population in the body
• Because of its size it is more efficient than IgG
It is the first antibody at the site of infection (primary response to infection)
IgA / • It comprises about 15% of Ig population in the body
• It is found in body secretions (tears, mucus, milk etc) & has close ties with mucus membranes
It is the first Ig to work & prevent attachment of offending cells
IgD / • It is present in about 0.2% of Ig population & its role is unclear without any antibody response
IgE / • It is only present in 0.004% of Ig population
It has a dual function. One it is involved in worm infections (parasites) & shows with an increase in Eosinophils. Secondly it
mediates the immediate allergic response.
2)CATEGORIES OF IMMUNITY
• Immunity may be broken down 2 ways:
1) May be ACTIVE OR PASSIVE
a)ACTIVE:- Body produces it very slowly over time (called seroconversion)
- Immunity most often lasts forever
b) PASSIVE:- Not produced by body. Instead it is received from someone else such as through
mother’s milk or injection
- Organism not stimulated to produce its own Ig.
- Immunity doesn’t last forever
2) May be NATURALLY OR ARTIFICIALLY ACQUIRED:
a) NATURALLY:- Mother having a baby or getting a cold
b) ARTIFICIALLY:- Given by doctor (ie: vaccine)
• So we can have the following 4 scenarios:
1. Naturally acquired Active Immunity:- You come into contact with the organism & become ill
- Confers lifetime immunity most of times
2. Artificially Acquired Active Immunity:- Immunizations such as DPT, Measles etc
- Confers lasting immunity in most cases
3. Naturally Acquired Passive Immunity:- Mother passes immunity on via placenta or breast feeding (no Ab produced
by the person receiving it)
- Doesn’t confer lasting immunity
4. Artificially Acquired Passive Immunity:- Received via medical profession in form such as rabies Ig , HaIg, HbIg etc.
Does not confer lasting immunity & doesn’t stimulate immune system
FOOD BORNE ILLNESSES
1) General Info:
• CDC estimates 75 million cases/year of food poisoning & 5000 deaths with 325,000 hospitalized/year
• Listeria has a 50% death rate even in HEALTHY individuals
• Yearly estimated lost productivity due to Food Borne illnesses is $ 17 billion
• In order of what causes most food poisonings: 1st: Restaurants (poor attitudes, poor refrigeration)
2nd: salt intake
3rd: Preservatives
4th: in processing
By Percentage:
Percentage / Factor Involved47% / inadequate refrigeration
21% / food prepared to far in advance
21% / infected person (poor hygiene)
16% / Inadequate cooking/holding temperature
12% / Inadequate reheat
11% / Contaminated raw ingredients
7% / Cross contamination
2) 20/20 Video:
• Largest food case in USA: 224, 000 by ice cream infected with Salmonella
• Causes of food poisoning are : 1) bacteria2) Chemical (mercury)
3) Viruses (Norfolk & Hepatitis A &B)4) Parasite (trichinella)
• Bacteria causes 2/3 of all outbreaks & is responsible for 90% of cases
3) INTOXICANT OR INFECTANT:
The causal bacteria/viruses may cause infection or release toxins that are poisonous to body
Offending Substance / Intoxicant/InfectantS. Aureus (#1 cause) / • Intoxicant that is self limiting & underreported
Salmonella (#2 cause) / • Intoxicant due to fecal contamination
Shigella / • Intoxicant Dysentery via water
C. Perfingens / • Intoxicant grows in soups/stews @ bottom of pot
Campylobacter / • Intoxicant Poultry
E. Coli / • Intoxicant & infectant
B. Cereus / • Intoxicant
C. Botulinum / • Intoxicant as a neurotoxin
Vibrio para hemolyticus / • Intoxicant & infectant (mostly the latter)
Vibrio Cholera / • Intoxicant & infectant (mostly the latter)
Y. enterocolitica / • Intoxicant & infectant (mostly the latter)
Listeria monocytogenes / • Intoxicant & infectant (mostly the latter)
SEXUALLY TRANSMITTED DISEASES/INFECTIONS
1) GENERAL INFORMATION:
• Many people may have multiple infections (ie: chlamydia/gonorrhea or herpes/HIV)
• Many STD’s go unrecognized especially in women where the symptomatology is not as obvious
• There are over 20 sexually transmitted diseases, may of which are transferred by other modes such as blood, towels etc
• Public health services estimates cost of lost work etc is $5 billion per year
• Men report STD’s more often than women because symptoms are more pronounced in males
2)GONORRHEA (reportable disease):
• Used to be called the “CLAP” or “DRIP” & is caused by Neisseria Gonorrhea (gm - diplococcus)
• Used to be # 1 reportable disease until surpassed by Chlamydia
• Gonorrhea is a fastidoious bacteria requiring very little oxygen (cultivated in candle jar), special media (chocolate agar/thayer martin)
& narrow temperature range (37 +/- 2 Celsius)
In females, 75-80% are asymptomatic or with few symptoms. In severe cases there may be infection of the cervix, abnormal periods, lower backache & can lead to endometriosis/peritonitis.
In males, 5% are asymptomatic, 20 % have mild symptoms (frequent urination, light discharge with some burning) & 75% have severe symptoms ( heavy yellow/green discharge. 3-9 days before discharge there is burning painful urination. Prostate may be infected leading to dysuria & blood in urine)
possible to have ophthalmic gonorrhea ( all newborns have silver nitrate in eyes to prevent infection)
Gonorrhea is treatable/curable with antibiotics (penicillin). However, there is one strain that is not (PPNG; has enzyme that destroys Beta-Lambda ring in penicillin [NBCE]. In this case use Spectinomycin, tetracyclines & ceftriaxones)
3) SYPHILIS:
• Until the advent of HIV/AIDS this was the only STD that was fatal unless treatment was sought.
• Many famous people died of this disease (napoleon, Al Capone etc)
• Occurs in three distinct phases:
1. Primary syphilis:- Characterized by a CHANCRE at site of Contact. It lasts 2-6 weeks & Heals Spontaneously.
The chancre is about 1/4” - 1” in diameter, moist, coloured (purplish/red), NON painful with raised edges.
AFTER 2-4 months
2. Secondary Syphilis:- This is characterized by a RASH or other cutaneous manifestations that last 2-3 weeks & Heals Spontaneously. there may also be fever, swollen lymph glands, headaches, hair loss, jaundice & moth eaten scalp alopecia. Warts, & condyloma may also be seen.
AFTER 20-30 yrs
3. Tertiary Syphilis:- This is characterized by GUMMA & some people actually never come out of the latent phase never reach 3 syphilis stage. The Gumma is a cancerous like growth in Liver, Spleen, Heart & Kidney or Brain
- Most commonly seen is Neurosyphilis & cardiosyphilis
Syphilis is treatable with Penicillin & two blood tests can be done to find it:
1. Non trepomenal test (wasserman)- Non specific test of olden days produced many false Positive results
2. Trepomenal Specific (Immunoflorescence)- Dark field microscopy that uses silver stain to better see the bacteria
3)CHANCROID:
• It is often misdiagnosed as syphilis because they look very similar. However the Chancroid ulceration is very different. It is characterized by:
- Well defined border- No exudate & unpigmented lesion- Painful elevated necrotising lesion
- When it heals may leave a scar- Untreated it can go on for months- Swelling of lymph nodes
• Incubation period is 3-5 days (syphilis is 14-30 days)
Treatment is Erythromycin, Ceftriaxone (penicillin is useless)
4)GENITAL WARTS:
• Caused by Acuminata Condyloma (associated with HPV 1- 60 antigenic strain)
• The genital warts are HPV 6 & 11 whereas the Cervical neoplasia is HPV 16 & 18
• The incubation period is 23 months (with a possible range of 1 - 20 months)
Appearance is of clusters of cauliflower like soft warts
Treatment is to surgically remove with laser, chemicals, & Liquid nitrogen
SEXUALLY TRANSMITTED DISEASES/INFECTIONS
5)GENITAL HERPES:
• This is caused by the Herpes Symplex Virus. HSV 1 is oral & HSV II is genital (although there now is little difference between the two).
• There are 33 million infected people & 200, 000 new cases/year. It is highly contagious with an incubation period of 7-10 days
There is a danger in pregnancy of infecting the newborn & possibly causing encephalitis
Symptoms present as fluid filled vesicles that have thin walls & easily broken. With the first infection we have fever, flu like symptoms, itching, headache. Subsequent reactivation is milder & may last 1-2 weeks. (recurring outbreaks occur during times of stress, fatigue, diet & friction of skin, sun & menstruation)
We now believe that the disease is transmittable even when there is NO Skin symptoms!!
Treatment is with Acyclovire (herpicin) which holds down the symptoms but DOES NOT CURE.
6) CHLAMYDIA:
• 80 % of people infected are not even aware that they have this disease. It is the most common reported STD with 4 million cases/year.
• It is caused by C. truchomatis
The symptoms mimic Gonorrhea & it is often called “Non Gonococcal Urethritis” NGU or Non Specific Urethritis (NSU)
It causes scar thickening of fallopian tubes, sterility, PID, peritonitis & possibly miscarriage. Some patients may have pelvic discomfort & painful urination occurs in both sexes.
May also cause Lymphogranuloma Venerium (LGV); a secondary swelling of inguinal lymph nodes (BUBOS) This Bubos is not seen in USA but worldwide it is common.
7)VAGINITIS:
• This is a common disease of female genital organs that may be caused by 3 factors:
- Bacterial ( Gardnerella [NBCE] Fishy, musty odour)
- Protozoan (Trichomonas)
- Yeast ( Candida Albicans; cottage cheese discharge). Often due to susceptibility, antibiotics, diabetics, pregnancy, birth control pills, immune compromised individuals & smoking/stress/poor diet
8)AIDS/HIV INFECTION:
• AIDS is not a disease but a syndrome & is not directly caused by an HIV infection.
• CDC defines AIDS as: - A disabling/life threatening illness caused by the HIV virus characterized by Encephalopathy, Wasting Syndrome or certain diseases due to immunodeficiency in a person with laboratory evidence for HIV infection or without certain other causes of immunodeficiency.
• In USA AIDS is no longer in the to 10 killer category (except in the 25-30 yr group)
• Because of complacency HIV infection rate is up (1. 3 million HIV infected & 300,000 people in USA have AIDS)
• Media coverage is wide with many: - Entertainers (Rock Hudson, Freddy Mercury, Liberace, Robert Reed, John Holmes, Brad Davis)
- Sports Figures (Arthur Ash, Greg Louganis)
- Politicians (Roy Cohn)
- Common Folk (K. Bergalis; dentist infected her. Ryan White; kid who wasn’t allowed to go to school)
• AIDS Controversial Aspects:- Association in school settings
- Sports participation (Magic Johnson)
- Workplace Confidentiality (Doctors, Nurses)
- GRID (Gay disease)
• Diagnosis of AIDS is made when the following 3 requirements are met:
1) Evidence of HIV Virus infection as screened by ELISA TESTConfirmed by WESTERN BLOT TEST
(IT takes the body between 30-90 days to develop antibodies to the virus. Some people may be shorter & others have taken years)
2) Immunodeficiency must exist & is determined by the number of T Lymph in circulation (CD4) count. There are 4 recognized stages. Only when the patient reaches the final stage are they then diagnosed with AIDS
a. Asymptomatic stage: -CD4 Count is 1200 or higher.
b. Early stages:-CD 4 count between 500-800
- patient has flu like symptoms, skin rashes, oral ulcers, lymphadenopathy
c. Late Stages:- CD 4 Count between 200-500
- Patient has oral thrush, Herpes, ulcers, anorexia, diarrhoea, nausea, fever, fatigue, night sweats
d. Advanced disease/AIDS:- Must have CD 4 BELOW 200
- patient has weakness, cachexia, malnutrition, memory/cognitive impairment, Altered mental state,difficulty walking or swallowing, cough, wheezing, vision problems, numbness in extremities
3) Opportunistic Infections must then occur, some of which are as follows:
- Most common is pneumocystis pneumonia (protozoan) followed by Toxoplasmosis (protozoan), Cryptosporidium (protozoan), Tuberculosis (bacteria) & then Cryptococcosis (fungal)
- Most common cancer is Kaposi sarcoma followed by Lymphoma
Patient with CD4 below 50 are in life threatening situations
SEXUALLY TRANSMITTED DISEASES/INFECTIONS
8)AIDS/HIV INFECTION:
• AIDS CASES SINCE 1980 Percentage by GROUP ACTIVITY
GROUP ACTIVITY / PERCENTAGEHomosexual/bisexual men / 57%
Drug IV user / 23%
Homosexual & IV drug user / 6%
Heterosexual (increasing rapidly) / 6%
Hemophiliacs / 1%
Transfusion recipient / 2%
Other / 5%
• THE VIRUS:
- It is spherical in shape & measures 100nm in diameter & has a Lipid bilayer around it.
- It is extremely fragile (exposure to light, air, water, cold will kill it) needs direct contact to transmit - It has spikes/knobs on outer lipid bilayer which are protein in nature
- It is an RNA retrovirus (requires reverse transcriptase enzyme allowing DNA to form from RNA)
• SOME STATISTICS:
- Worldwide about 50 million infected with HIV with 5.6 million newly infected in 1999
- In the USA about 300,000 AIDS cases with about 900,000 HIV cases
- HIV/AIDS is #1 killer of age group 25-45
- Spermicide (nonoxynol-9) does not offer any protection against HIV virus
• AIDS TREATMENT:
- Death rate is going down due to the medication now available for AIDS
- In NY state, hospitals, Nursing care & Home care programs are available for AIDS patients. The costs are borne by individual insurances & if need be by the Gov’t (via medicare/medicaid).
- Approximate cost on yearly basis for medication etc is $52,000.00