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Food & Water Borne Infections (Selected
Enterics)
Prof. Marohren C. Tobias-AlturaCollege of Public Health
University of the Philippines Manila
Notifiable DiseasesNotifiable DiseasesA.A. Acute bloody diarrheaAcute bloody diarrheaB. Acute hemorrhagic feverC. Acute lower respiratory
tract infection & pneumonia
D.D. Acute watery diarrheaAcute watery diarrheaE.E. CholeraCholeraF. DiphtheriaG. FilariasisH. LeprosyI. LeptospirosisJ. MalariaK. Measles
A. Meningococcal infectionB. Neonatal tetanusC. Non-neonatal tetanusD. Paralytic shellfish
poisoningE. Rabies (human)F. SchistosomiasisG.G. Typhoid & paratyphoid Typhoid & paratyphoid
feverfeverH. Viral encephalitisI. Viral hepatitisJ. Viral meningitisK. Whooping cough
National Epidemic Sentinel Surveillance System - NEC (NESSS) of the DOH
TEN LEADING CAUSES OF MORBIDITY TEN LEADING CAUSES OF MORBIDITY No. & Rate/100,000 Population No. & Rate/100,000 Population PHILIPPINES, 2004PHILIPPINES, 2004
CAUSE MALE FEMALE BOTH SEXES
Rate** Rate** Number Rate*
1. Acute Lower RTI and Pneumonia
888.8 868 776,562 929.4
2. Bronchitis/Bronchiolitis 651.8 817.1 719,982 861.6
3. Diarrheas 668.5 651.5 577,118 690.7
4. Influenza 400.7 444.6 379,910 454.7
5. Hypertension 338.2 442.1 342,284 409.6
6. TB Respiratory 137.7 93.9 103,214 123.5
7. Chickenpox 51.5 56.2 46,779 56
8. Diseases of the Heart 38.5 45.1 37,092 44.4
9. Malaria 24 20 19,894 23.8
10. Dengue fever 17.8 17.1 15,838 19Source: 2003 FHSIS Annual Report** rate/100,000 of sex-specific pop.* Total population of regions with reports only
TEN LEADING CAUSES OF MORBIDITY TEN LEADING CAUSES OF MORBIDITY No. & Rate/100,000 Population No. & Rate/100,000 Population PHILIPPINES, 2010PHILIPPINES, 2010
CAUSE MALE FEMALE BOTH SEXES
Rate** Rate** Number Rate*
1. Acute Respiratory Infection 888.8 868 776,562 929.4
2. Acute Lower RTI and Pneumonia
651.8 817.1 719,982 861.6
3. Bronchitis/Bronchiolitis 668.5 651.5 577,118 690.7
4. Hypertension 400.7 444.6 379,910 454.7
5. Acute watery diarrhea
338.2 442.1 326,551 347.6
6. Influenza 137.7 93.9 103,214 123.5
7. UTI 51.5 56.2 46,779 56
8. TB Respiratory 38.5 45.1 37,092 44.4
9. Injuries 24 20 19,894 23.8
10. Diseases of the heart 17.8 17.1 15,838 19
Source: 2003 FHSIS Annual Report** rate/100,000 of sex-specific pop.* Total population of regions with reports only
Acute Bloody Diarrhea morbidity rate by region (Philippines, 2005)
Lacking data or underreported
Acute watery diarrhea morbidity rate by year, 1992-2005
Acute watery diarrhea morbidity rate by region (Philippines, 2005)
Cholera morbidity rate by yearPhilippines, 1999 - 2005
Outbreak in Sultan Kudarat
Cholera morbidity rate by regionPhilippines, 2005
Typhoid & Paratyphoid Fever morbidity rate by year (Philippines, 1992 – 2005)
Outbreak in Laguna
Typhoid & Paratyphoid Fever morbidity rate by region (Philippines, 2005)
TEN LEADING CAUSES OF MORBIDITY No. & Rate/100,000 Population PHILIPPINES, 2003
CAUSE MALE FEMALE BOTH SEXES
Rate** Rate** Number Rate*
1. Acute Lower RTI and Pneumonia
770.9 748.2 674,386 861.2
2. Diarrheas 695.0 655.0 615,692 786.2
3. Bronchitis/Bronchiolitis 639.6 677.0 604,107 771.4
4. Influenza 455.4 503.1 431,216 550.6
5. Hypertension 325.4 420.7 325,390 415.5
6. TB Respiratory 126.4 84.0 92,079 117.9
7. Heart Diseases 28.8 29.2 30,398 38.8
8. Malaria 41.1 30.4 28,549 36.5
9. Chickenpox 30.3 30.4 26,137 33.4
10. Measles 30.2 30.4 25,535 32.6Source: 2003 FHSIS Annual Report** rate/100,000 of sex-specific pop.* Total population of regions with reports only
2003 # 2
2002 # 2
2001 # 1
2000 # 1
TEN LEADING CAUSES OF MORTALITY By Sex No. & Rate/100,000 Population, Phils, 2003
1. Heart Diseases 38,677 29,019 67,696 83.5 17.1
2. Vascular System Diseases 29,054 22,814 51,868 64.0 13.1
3. Malignant Neoplasm 20,634 18,664 39,298 48.5 9.9
4. Accidents 27,720 6,246 33,966 41.9 8.6
5. Pneumonia 15,831 16,224 32,055 39.5 8.1
6. TB, all forms 18,367 8,404 26,771 33.0 6.8
7. Symptoms, signs and abnormal clinical, laboratory findings, NEC
10,740 10,623 21,363 26.3 5.4
8. Chronic lower respiratory diseases
12,998 5,907 18,905 23.3 4.8
9. Diabetes Mellitus 6,823 7,373 14,196 17.5 3.6
10. Certain conditions originating in the perinatal period
8,397 5,725 14,122 17.4 3.6
CAUSE MALE FEMALE BOTH SEXES Number Rate* Percent
Source: The2003 Philippine Health Statistics*percent share from total deaths, all causes, Philippines
unsafe water, along with food, is implicated in 3 million deaths
about 2.4 billion episodes of illness per year -WHO
Diarrhea & gastroenteritis of presumed infectious Diarrhea & gastroenteritis of presumed infectious origin as CAUSE of DEATHS among infants, origin as CAUSE of DEATHS among infants, under 5, children 5-9 ; PHILIPPINES, 2000under 5, children 5-9 ; PHILIPPINES, 2000
Infants 0-12 months old
0.7 rate per 1,000 live births
Children 1-4 years16.14 rate per 100,000 children
Children 5-9 years2.19 rate per 100,000 children
#8 #1 is pneumonia#2 bacterial sepsis
#3#1 pneumonia, #2 accidents
#5#1 accidents#2 pneumonia
Food & Waterborne diseases
Bacterial InfectionsBacterial Food PoisoningViral GastroenteritisPrevention and Control
Outline
Bacterial Infections CholeraShigellosisTyphoid feverSalmonellosisDiseases caused by E. coli
EnterobacteriaceaeOften referred as enterics
General Characteristics • Gram(-) bacilli/coccobacilli• Facultative anaerobes• Glucose fermenters• Oxidase-negative• Reduce nitrates to nitrites
Virulence and Antigenic Factors
• Ability to colonize, adhere, produce various toxins and invade tissues
• Some possess plasmids that may mediate resistance to antibiotics
• Many enterics possess antigens that can be used to identify groups:– O antigen – somatic, heat-stable antigen located in the cell
wall– H antigen – flagellar, heat labile antigen– K antigen – capsular, heat-labile antigen
Antigenic Structure
• O antigen: Lipopolysaccharide
• K antigen: Capsular• H antigen: Flagellar
Shigella
Shigella
S. dysenteriae -Group AS. flexneri -GroupBS. boydii -Group CS. sonnei -Group D– gram-negative rods
cannot ferment lactose, no capsulenon-motile
Shigella - natural reservoir & transmission
man only "reservoir"mostly young children
fecal to oral contactchildren to adults
transmitted by adult food handlersunwashed hands
ShigellaDiseases--ShigellosisSymptoms start 1-3 days after exposure
with profuse watery diarrhea. Disease can stop here.
Can progress to dysentery, which is an intestinal inflammation with abdominal pain, intense diarrhea, relatively scant stool with blood, mucous, and white blood cells (pus)
Symptoms usually resolve on their own in 1 weekRarely, an infected person becomes a carrier
ShigellaDiseases--Shigellosis
More severe form of this disease is produced by S. dysenteriae type1A. This species produces a toxin-called Shiga toxin
Shigella-Pathogenic factors
IpaIpa (invasive plasmid antigen) A,B,C, and D proteins are secreted into host cells intracellular growth of Shigella 1st, bacteria invade intestinal cells by endocytosis2nd, escape from endocytotic vesicles and multiply inside the cells.3rd, directly invade adjacent cells4th, host cells die and mucosal abscess forms
Shiga toxin
classic A/B toxinB subunit binds to cells and gets A inside the cell. A inhibits protein synthesis
lysing 28S rRNAcytotoxic for intestinal cells
Treating shigellosis
manage dehydrationuse of antibiotics, controversial if case is not severepatients respond to antibiotics
disease duration diminished fluoroquinolone
Salmonella
Salmonella
>2000 antigenic O and H serotypesgenetically single species-maybe?
S. enterica, choleraesuisdisease category
S. typhiS. paratyphi
Salmonella
Natural reservoir: not humans, but many other animals, including birds, reptiles, many others and vegetation. Eggs are also a risk.Transmission is by ingestion of contaminated food products, especially poultry or dairy products. Some transmission by person to person can occur in children, health care, or food preparation if proper sanitation is not observed.
Salmonella typhi & paratyphi
Natural reservoir: only infected humans
Transmission: person to person by the oral-fecal route and by ingestion of water or food contaminated with human feces.
Salmonellosis
Gastroenteritis nausea vomiting non-bloody stool mostly, sometimes bloody with fecal leukocytessometimes fever, abdominal cramps, malaiseself-limiting (2 - 7 days)40,000 reported cases; 1.4 million total
Salmonellosis
Gastroenteritis identification- usually not cultured unless symptoms last a long time. Stool culturestreatment is just fluid and salt replacementantibiotics not recommended, with exceptions for very young, very old, immunocompromised, debilitated.
Typhoid fever
enteric feverseverest salmonella diseaseSalmonella typhi
S. paratyphi causes milder form of enteric fever endemic areas -Latin America, Philippines, Indian subcontinentepidemics
third worldEurope(historical)
Typhoid -Therapy
Antibiotics essentialcephalosporin like ceftriaxonefluoroquinolonetreatment must long lasting to eliminate carrier state
vaccine for visitors to endemic areas
Escherichia coli
Epidemiology & DiseasesStrain Diseases
ETEC Traveler’s diarrhea, infant diarrheaTraveler’s diarrhea, infant diarrhea in 3rd World. Watery diarrhea with cramps, nausea, sometimes vomiting.Self-limiting in 5 days.
EPEC Major cause of infant diarrheainfant diarrhea in 3rd World.
Epidemiology & Diseases
Strain Diseases
EIEC Mild shigella-like dysenteryshigella-like dysentery Common in Third World.
EAEC InfantInfant and child diarrhea in 3rd WorldPersistent watery diarrhea that generally last >14 daysOften the cause of chronic diarrhea in immunocompromised patients
Epidemiology & Diseases
Strain DiseasesEHEC After 3-4 days, watery, non-bloody
diarrhea. 25% get a bloody diarrhea with cramps and maybevomiting after 2-3 days. 5-10% develop hemolytic uremic hemolytic uremic syndromesyndromeOften, O157:H7 serotype
Virulence factors and pathogenicity
Strain Virulence Factors
ETEC 1 to 4 enterotoxinsenterotoxins, plasmid-mediated
EPEC Variety of proteins that lead to attachment & effacing/destruction
(A/E LesionsA/E Lesions) of microvilli. Plasmid-mediated.
Enterotoxigenic E. coli
Heat labile toxin (LT)–like choleragen–Adenyl cyclase activated –cyclic AMP –secretion water/ions
Heat stable toxin (ST)Guanylate cyclase activated cyclic GMPuptake water/ions
Enteropathogenic E. coli •destruction of surface microvilli
•fever•diarrhea•vomiting •nausea •non-bloody stools
Virulence factors and pathogenicity
Strain Virulence Factors
EIEC Variety of factors very similar to those of shigella (shiga-like toxinshiga-like toxin). Plasmid-mediated
EAEC Fimbriae which attach to intestinal cells
Enteroinvasive E. coli (EIEC )
•Dysentery- resembles shigellosis
Virulence factors and pathogenicity
Strain Virulence Factors
EHEC Stx-1 and Stx-2 toxins which are very similar to toxins of shigella. Toxin genes are on a lysogenic lysogenic phage.phage. Hemolysins.
• Vero toxin – “shiga-like”
• Hemolysins
• Many strains are unable to ferment unable to ferment sorbitol,sorbitol, whereas most other E. coli do ferment sorbitol.
Enterohemorrhagic E. coli
Vibrio species
Vibrio cholerae
Common characteristics
Gram-negativeshort, curved, rod-shapedrapidly motile due to single polar flagellumfacultative anaerobesgrowth of many vibrio strains requires or is stimulated by NaCl
Common characteristics
growth of many vibrio strains requires or is stimulated by NaClculture on blood or MacConkey agar
Pathogenesis
V. cholerae is transmitted by contaminated water and food. There are no known animal reservoirs, nor animal or arthropod vectors. Outbreaks of V. cholerae infection have been associated with raw or raw or undercooked seafoodundercooked seafood harvested from contaminated waters.
Pathogenesis
Following ingestion, V. cholerae infects the small intestine. Adhesion factors are important for colonization & virulence. The organism is non-invasive, and causes disease through the action of an enterotoxin (cholera toxin) that causes the activation of adenylate cyclase by ADP-ribosylation. This initiates an outpouring of fluid into the intestine.
Treatment
Replacement of fluids & electrolytes is crucial in preventing shock, & does not require bacteriologic diagnosisAntibiotics such as doxycycline can shorten the duration of diarrhea and excretion of the organism
Prevention
Public health measures that reduce reduce fecal contaminationfecal contamination of:–water supplies and food– adequate cooking of foodscan minimize transmission