TYPHOIDFEVER INCHILDREN

BYDR.ZULFIQAR BUTT

DEFINITION:Typhoid fever also known as Enteric

fever , is a potentially fatal multi systemic illness caused primarily by salmonella typhi and to lesser extent by para typhi A,B and C.

ETIOLOGY:Typhoid fever is caused by salmonella

typhi , a gram negative bacteria.A very similar but generally less severe

illness paratyphoid is caused by salmonella para typhi A,B and C.

Ratio of disease caused by salmonella typhi to that caused by salmonella paratyphi is 10:1.

EPIDEMIOLOGY:More than 21.7 million typhoid cases occur

annually.More than 200000 deaths occur annually , mostly

in Asia. In developed countries , incidence of typhoid is <

15 cases per 100000 population , mostly occurring in travelers.

In developing world , it ranges from 100 to 1000 cases per 100000 population.

Adult and children of all ages and both sexes are equally susceptible to infection.

Typhoid may be highest in children < 5 years of age.

TRANSMISION OF INFECTION Oro-fecal transmission occur.

transmission mostly occur through

contaminated water.Poor hygiene habits and poor public

sanitation conditions.Flying insects feeding on feces. Asymptomatic carrier of typhoid fever,

suffering with no symptoms, but are capable of infecting others.

Contaminated ice, ice-creams, milk and poultry products are also a source of infection.

PATHOGENESIS:After ingestion of contaminated food and

water , salmonella bacteria enter the body and invade small intestine and enter in peyer patches.

The bacteria are ingested by macrophages in peyer patches.

Bacteria then spread in regional lymph nodes inside macrophages and multiplication takes place.

Thru intestinal lymphatic the bacteria reaches to liver , spleen , gall bladder and bone marrow.

CONTINUED:At the end of incubation period , they pass in

blood stream and cause bacteremia and associated symptoms

In first week there is elevation of body temperature

In second week there is abdominal pain , spleen enlargement and rose spots

In third week there is necrosis of peyer patches which leads to perforation and bleeding

And if left untreated death is imminent.

CLINICAL FEATURES: The incubation period of typhoid fever is usually 7-14 days , and ranges between 3 and 30 days. The clinical presentations varies from a mild illness

with low grade fever ,malaise , dry cough to severe illness with abdominal distension and multiple complications.

In children , diarrhea may occur in earlier stages of illness, and may be followed by constipation.

The fever may rise gradually , but classic stepladder rise of fever is relatively rare.

In about 25% cases a maculopapular rash(rose spots) may be visible around the 7th to 10th day of illness ,appear in crops in lower chest and abdomen.

COMMON CLINICAL FEATURES OF TYPHOID FEVER IN CHILDREN ARE

1) High grade fever 95%2) Coated tongue 76%3) Anorexia 70%4) Vomiting 39 %5) Hepatomegaly 37%6) Diarrhea 36%7) Toxicity 29%8) Abdominal pain 21%9) Pallor 20%10)Splenomegaly 17%11)Constipation 7%12)Headache 4%13)Jaundice 2%14)Obtundation 2%15)Ileus 1%16)Intestinal perforation 0.5%

DIAGNOSISCOMPLETE BLOOD COUNT:Leucopenia may be present inspite of high

grade fever.There may be normocytic normochromic

anemia.Thrombocytopenia.ESR is raised.LFTS may be derrangedThere may be hyponatremia and

hypokalemia.

CULTURES: The mainstay of diagnosis of typhoid fever is a positive result

of culture. BLOOD CULTURE: Bacteremia occurs early in disease, so therefore blood

culture are positive in 1st week:90% cases 2nd week:75% cases 3rd week:60% cases 4th week and later 25% cases of blood cultures are positive. STOOL AND URINE CULTURES: results may become positive

after first week of illness(stool culture result s also occasionally positive in incubation period).

BONE MARROW CULTURE: is the most sensitive procedure positive in (85 to 90% cases),positive during the later stages of typhoid fever.it is an invasive procedure so collection of specimens are difficult.

SEROLOGICAL TESTS: WIDAL TEST: This test is used for detecting the antibody response

to the somatic O and flagelar H antigens of salmonella.

Two serum specimens are obtained at intervals of 7th to 10th days of disease.

Following titers of antibodies are significant when single sample is tested.

O> 1:160 H> 1:320 Widal test may give false positive or false negative

results , so therefore it is not a reliable test.

TYPHI DOT TEST:detects IgM and IgG antibodies against the

outer membrane protein (OMP) of the Salmonella typhi.

IgM is positive only: acute typhoid feverIgG is positive only: previous infection or

reinfectionIgM and IgG positive: acute typhoid fever

middle stageIgM and IgG negative: probably not typhoid.

POLYMERASE CHAIN REACTION:

PCR is used to amplify the specific genes of s typhi.

Gives result in few hours.More specific and sensitive than blood

culture.

MANAGEMENT:There are 2 steps of management of typhoid

fever.SUPPORTIVE MANAGEMENT: In this give adequate rest to the patient.Correct electrolyte and fluid imbalance.Antipyretic therapy.A soft , easily digestable diet should be continued

unless the patient has abdominal distension or ileus.

Corticosteroids are given in individuals with severe toxemia and prolonged symptoms , short course of dexamethasone initially at the dose of 3mg/kg is given , followed by 1mg/kg every 6 hours for 2 days.

CONTINUED:Blood transfusion is needed in a patient with

anemia or severe intestinal bleeding.If there is thrombocytopenia , platelet

transfusion is needed.Surgical intervention is required if there is

intestinal perforation.

SPECIFIC TREATMENT: Antibiotics used to treat typhoid fever are UNCOMPLICATED TYPHOID FEVER:a) FULLY SENSITIVE CASES:Chloramphenicol (50-75mg/kg/d) for 14 to 21 daysAmoxicillin (75-100mg/kg/d) for 14 daysQuinolones (15 mg/kg/d) for 5 to 7 daysb) MULTIDRUG RESISTANCE CASES:Quinolones (15mg/kg/d) for 5-7 daysCefixime (15-20mg/kg/d) for 7-14 daysAzithromycin (20mg/kg/d) for 7 daysc) QUINOLONE RESISTANT CASES:Azithromycin (10mg/kg/d) 7for 7 daysCeftriaxone (75mg/kg/d) for 10 to 14 daysCefixime (20mg/kg/d) for 7-14 days

SEVERE OR COMPLICATED TYPHOID FEVERa) FULLY SENSITIVE CASES:Ampicillin (100mg/kg/d) for 14 daysCeftriaxone (60-75mg/kg/d) for 10-14 daysQuinolones (15mg/kg/d) for 10-14 daysb) MULTIDRUG RESISTANT CASES:Quinolones (15mg/kg/d) for 10-14 daysCeftriaxone (60mg/kg/d) for 10-14 daysCefotaxime (80mg/kg/d) for 10-14 daysc) QUINOLONE RESISTANT CASES:Ceftriaxone (75mg/kg/d) for 10-14 daysAzithromycin (20mg/kg/d) for 7 days

COMPLICATIONS: IN GIT AND HEPATOBILLIARY SYSTEM : acute cholecystitis , hepatitis ,

hepatic abscess , splenic abscess , intestinal hemorrhage and intestinal perforation.

IN CENTRAL NERVOUS SYSTEM : Psychosis ,cerebral edema ,cerebral abscess, meningitis, encephalopathy, GBS.

IN CARDIOVASCULAR SYSTEM: Endocarditis , myocarditis, pericarditis , CHF.

RESPIRATORY SYSTEM : Pneumonia , empyema

BONE AND JOINTS: Osteomyelitis , septic arthritis

GENITOURINARY SYSTEM: Uti , renal abscess, pyelonephritis

SOFT TISSUES INFECTIONS

DIFFERENTIAL DIAGNOSIS:GastroenteritisBronchopnuemoniaSepsisMalariaTuberculosisHepatitisLiver abscessMalignancies , such as leukemia and

lymphoma

PROGNOSIS:Prognosis depend upon the rapidity of diagnosis

and institution of appropriate antibiotic.Mortality rate is higher than 10% due to delay in

diagnosis and treatment.Enteric fever with complication is associated

with high morbidity and mortality.Children and infants with malnutrition are at

higher risk for adverse outcome.Relapse may occur in 2-4% children.<2% children becomes carrier , who excrete

salmonella typhi for more than 3 months after infection.

PREVENTION: Improved personal hygiene and hand washing are

important preventing measures. Improved sanitary habits. Protective health measures like provision of clean

water , adequate sewage disposal and control of flies are also important.

Clean and wash foods thoroughly. Adequate temperatures for cooking. Eggs should be thoroughly cooked and never eaten

raw. Avoid preserving food at warm temperature and

reheating food.

VACCINATION:There are Two types of vaccines:1) VIVOTIF: A live attenuated vaccine , given orally ,4 capsules on alternate days ,not given to children younger than 6 years of age , recommended every 5 years If exposure continued , efficacy is 67-87%.

2) TYPHERIX,TYPHIM Vi: An inactivated vaccine composed of purified capsular polysaccharide , given intramuscular ,given to children aged 2 years and older , booster needed every 3 years if exposure continued, efficacy is 70-80%.

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