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