INFECTIOUS DISEASES IN THE PHILIPPINES

What is an Infectious Disease caused by a biological agent invasion of a host organism by a

foreign replicator, generally microorganisms, often called microbes, that are invisible to the naked eye.

requires an agent and a mode of transmission (or vector).

HOW ARE INFECTIOUS DISEASES DIAGNOSED?

Diagnosis• Diagnosis is initially by medical history and

physical examination, and imaging, but the principal tool in infectious disease is the microbiological culture.– Types of cultures include:• Blood culture • Sputum culture • Tissue culture • Culture of various fluids such as pleural fluid and

peritoneal fluid • Urine culture

WATER AND FOOD BORNE DISEASE

Water and Food Borne Diseases Food borne illnesses are defined as

diseases, usually either infectious or toxic in nature, caused by agents that enter the body through the ingestion of food

Water and Food Borne Diseases Typhoid Fever Hepatitis A Cholera Amoebic dysentery E. coli diarrheal illness Bacillary dysentery

TYPHOID FEVER

Typhoid Fever Etiologic agent:

• Salmonella typhosa

Source of infection:• Feces and urine of infected persons,

transient carriers

Epidemiology Description:

A systemic infection characterized by: Continued fever Anorexia Slow pulse Enlargement of spleen Rose spots on trunk diarrhea

TYPHOID FEVER Mode of transmission:

Direct or indirect contact with patient or carrier

Contamination by hands of carrier Flies

Incubation period: Average of 2 weeks

TYPHOID FEVER Period of communicability:

As long as typhoid bacilli appear in excreta, usually form 1st week and throughout convalescense

Cases of Typhoid Fever in the Philippines

0

5000

10000

15000

20000

25000

1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002

Data taken from an official report done by the DOH the Republic of the Philippines: http://www2.doh.gov.ph/data_stat/html/fhsis/nd_byear.pdf

Cases of Typhoid Fever in Philippines & Japan

0

5000

10000

15000

20000

25000

1982 1985 1988 1991 1994 1997 2000

PhilippinesJapan

•Statistics obtained from: www.WHO.int/en/

2 PHASES OF TYPHOID FEVER 1st phase:

the patient's temperature rises gradually to 40ºC, and the general condition becomes very poor with sweating, no appetite, coughing and headache. Constipation and skin symptoms may be the clearest symptoms. Children often vomit and have diarrhea. The first phase lasts a week and towards the end the patient shows increasing listlessness and clouding of consciousness.

2 PHASES OF TYPHOID FEVER 2nd phase:

in the second to third weeks of the disease, symptoms of intestinal infection are manifested and the fever remains very high and the pulse becomes weak and rapid. In the third week, the constipation is replaced by severe pea-soup-like diarrhea. The feces may also contain blood. It's not until the fourth or fifth week that the fever drops and the general condition slowly improves.

DIAGNOSIS Bacilli can be isolated from the blood

early in the disease and from urine or feces after the 1st week

Agglutination reaction becomes positive during the 2nd week.

TREATMENT For sensitive organisms, include

Chloramphenicol or IV ampicillin for 3 weeks or ceftriaxone for 5 to 10 days

For resistant organisms to initial drugs, alternative of ciprofloxacin or furazolidone

PREVENTION• Vaccination• Other preventive measures for travelers to high-risk areas include

the following:– Only use water that has been boiled or chemically disinfected for:

• Drinking, or preparing beverages, such as tea or coffee• Brushing teeth• Washing face and hands (can also use alcohol-based gel to wash hands)• Washing fruits and vegetables• Washing eating utensils and food preparation equipment• Washing the surfaces of tins, cans, and bottles that contain food or beverages

– Do not eat food or drink beverages from unknown sources– Do not put ice in drinks– Avoid eating food from street vendors – Any raw food could be contaminated and should be avoided, including:

• Fruits and vegetables, particularly those that cannot be peeled • Salad greens • Unpasteurized milk and milk products• Raw meat• Shellfish• Any fish caught in tropical reefs rather than the open ocean

HEPATITIS A

HEPATITIS A Etiologic Agent:

Hepatitis A virus, single stranded RNA virus

Other names: Infectious hepatitis Epidemic hepatitis Catarrhal jaundice

HEPATITIS A Predisposing factors:

Poor sanitation Contaminated water supplies Unsanitary method of preparing serving of

food malnutrition

HEPATITIS A Incubation period:

15-50 days Description:

Influenza like such as HA malaise and easy fatigability anorexia and abdominal discomfort nausea and vomiting Fever Jaundice accompanied by pruritus and urticaria

HEPATITIS A Period of Communicability

Maximum infectivity during the latter half of the incubation period, continuing for a few days after onset of jaundice

No carrier state or chronic infection

HEPATITIS A Diagnosis:

Demonstration of virus in stool or by four fold or greater rise of IgM antibodies against Hepa A

Anti-HAV (IgM) – recent acute infection Anti-HAV (IgG) – past HAV infection

HEPATITIS A Prevention:

Immunization Good sanitation and personal hygiene Proper sanitary disposal of feces Careful handwashing

CHOLERA (EL TOR)

CHOLERA Etiologic agent:

Vibrio El Tor Vibrio cholerae

A curved, alkali and salt tolerant, Gram (-) rod bacterium

CHOLERA Sources of infection:

Vomitus and feces of infected persons Feces of convalescent or healthy carriers

Incubation period: Few hours to 5 days

CHOLERA Description:

An acute serious illness characterized by: Sudden onset of acute and profuse colorless

diarrhea Vomiting Severe dehydration Muscular cramps Cyanosis Shock and death may occur because of fluid

loss from the circulatory system

CHOLERA Period of communicability:

7-14 days after onset

Diagnosis: Culture of vomit or feces

Prevention: Immunization Purification of water Careful handwashing

CHOLERA Treatment

Rehydration with a solution of electrolytes and glucose given IV in severe cases or by mouth in milder cases

AMOEBIASIS

AMOEBIASIS Etiologic agent:

Entamoeba histolytica, a protozoan

Mode of Transmission: Contaminated water containing cysts from

feces of infected persons Spread by hand to mouth transfer of feces Contaminated raw vegetables Flies Sexually transmitted

AMOEBIASIS Reservoir:

Man, usually a chronically ill or asymptomatic cyst passer

Description: Intestinal disease varies from acute,

fulminating dysentery with fever, chills and bloody mucoid diarrhea to mild abdominal discomfort with diarrhea containing blood or mucus

AOMEBIASIS Incubation period:

Variable, from a few days to several months

Period of communicability: During the period of cyst passing, this may

continue for years

Amebiasis Diagnosis:

Direct microscopic demonstration of trophozoites or cysts in fresh fecal specimen

Smears obtained by proctoscopy Aspirates of abscesses or tissue secretions

AMEBIASIS Prevention:

sanitary disposal of human feces Protection of public water supplies against

fecal contamination Fly control and protection of food, fruits and

vegetables against fly contamination

Treatment: Metronidazole Paronomycin

ESCHERICHIA COLI DIARRHEAL ILLNESS

E. coli Diarrheal Illness Etiologic agent:

Escherichia coli

Incubation period: 12-72 hours

E. coli Diarrheal Illness Manifestations:

ETEC (Enterotoxigenic E. coli) Watery diarrhea without blood or mucus “Traveler’s diarrhea” Self limiting Prophylaxis : bismuth subsalicylate and with use of

antimicrobial chemoprophylaxis EPEC (Enteropathogenic E. coli)

No enterotoxins Mechanism not known Common cause of infantile diarrhea Self-limiting

E. coli Diarrheal Illness Manifestations:

EIEC (Enteroinvasive E. coli) Less volume but with bloody mucoid stools Fever Headache Myalgia

EHEC (Enterohemorrhagic E. coli) Serotype O157:H7 Bloody diarrhea Severe abdominal cramps Nausea and vomiting Self-limiting

E. coli Diarrheal Illness Manifestations:

EAEC (Enteroadherent E. coli) Associated with both acute and chronic diarrhea

Mode of transmission: Fecal-oral route

Reservoir Commonly asymptomatic carrier

E. coli Diarrheal Illness Diagnosis:

Stool culture and serotyping

Prevention: Personal hygiene Handwashing Proper sanitary fecal disposal

E. coli Diarrheal Illness Treatment:

Replacing the fluid from vomiting and diarrhea

Infants may require antibiotics such as gentamycin for a few days or flouroquinolones

BACILLARY DYSENTERY (SHIGELLOSIS)

Bacillary Dysentery (Shigellosis) Etiologic agent:

Four main groups: S. flexneri S. boydii S. sonnei S. dysenteriae

Bacillary Dysentery (Shigellosis)

Source of Infection: Feces of infected persons, many in apparent

mild and unrecognized infections. Description:

An acute bacterial infection of the intestine characterized by Diarrhea Fever Tenesmus in severe cases bloody and mucoid stools.

Bacillary Dysentery (Shigellosis) Mode of Transmission:

Eating contaminated foods drinking contaminated water or milk by hand to mouth transfer of contaminated

materials by flies by objects soiled with feces of a patient or

carrier.

Bacillary Dysentery (Shigellosis) Incubation Period:

1 day, usually less than 4 days.

Period of Communicability: During acute infection and until

microorganism is absent from feces.

Bacillary Dysentery (Shigellosis) Prevention:

Sanitary disposal of human feces sanitary supervision of processing, preparation

and serving of food particularly those eaten raw

fly control and screening to protect foods & water against fly contamination.

Bacillary Dysentery (Shigellosis) Treatment:

Antibacterial medications such as ampicillin and cotrimoxazole (trimethoprim /

sulfamethoxazole) shorten the duration of symptoms and time shigellas are excreted