21 محرم 1435 هـ Pediatric Lec.
27/12/2013
CHOLERA
Definition : A severe gastrointestinal infection caused by vibrio cholerae.
Aetiology :
curved gram negative aerobic bacillus with polar flagellum.
Antigenically divided into : classic=V.cholera 01 and El Tor ,and further subdivided into subtypes Inaba and Ogawa. It may produce sporadic cases , small outbreaks or pandemic spread,especially in the Indian subcontinent but spread later to Africa and South America. In Iraq , several outbreaks took place in the twentieth century .Most outbreaks came from India through the port of Basrah.
Transmission is usually by contaminated water and food. Infection requires large number of organisms to avoid being killed by normal gastric acidity. The organism colonize the small intestine and activate cyclic adenosine monophosphate (cAMP) that blocks the absorption of Cl. And water by crypt cells in massive outpouring of electrolyte –rich isotonic fluid into small bowel resulting in severe diarrhoea, it contains a large amount of Na.,Cl.,K.,and bicarbonate. This leads to hypovolemia , low BP ,shock and metabolic acidosis.
Clinical feature :
I P 18 hrs.- 5 days.The onset is acute with vomiting and diarrhea with no abdominal pain and fever .
The stool is copius ,almost colourless with little mucus " rice water" The child get restless , thirsty then lethargic and unconscious with sunken eyes, dry tongue, weak pulse delayed capillary refill , low B.P. and no output of urine. Hypoglycemia and seizure may follow ending up in coma and death. However many infected children may be symptomless or have mild diarrhea.
Lab . results : Na. low, Cl. Low, K.low., metabolic acidosis, hemoconcentration, increased osmalality, stools contain few pus cells and RBC.
Diagnosis :
During outbreaks is clinical. For confirmation Dark Field microscopy of stool .A special medium for transport and culture.
Differential Diagnosis :
Rota virus or E.Coli infection, and other diarrhoeas
Complications :
Acute tubular necrosis from dehydration
Pulmonary edema( over hydration)
Paralytic ileus
Tetany
Treatment :
O R S (WHO) as much as the patient can take
If ileus or shock give IV Ringer lactate ( cholera cot)
Antibacterials-tetracycline 50 mg/kg / day divide qid orally for 3 days.or Doxycycl 5 mg/kg one single dose, to shorten duration and excretion of organism. Children less than 9 yrs of age give cotrimoxasole (8-10mg / kg /day trimethoprim + 40 mg/kg/day sulfosoxasole, divided qid. Or Furazolidone 5-8mg/kg/day.
Prevention :
safe water and food . The infection does not give permanent immunity.Vaccine –oral vaccine recommended by WHO.
كَم أَبلَتِ الدُنيا وَكَم جَدَّدَت *** مِنّا وَكَم تُبلي وَتَغتالُما أَحسَنَ الصَبرَ وَلا سِيَّما *** بِالحُرِّ إِن ضاقَت بِهِ الحالُ
"علي بن الجهم"