ENTERIC EEVER IN THE TROPICS 221 



Drop il into a mixture of oxbile 90 c.c, glycerine 10 c.c, and pep- 

 tone 2 grm., distributed into small flasks each containing 20 c.c. of 

 the medium. 



Incubate and test as above. 



Ehrlich and Diazo Reaction. 



Generally present in typhoid during the second and third week. 



It may be absent in very mild cases. 



V^ery active tuberculosis gives it fairly constantly. 



jMeasles gives it more frequently than German measles. 



If it is present it is not diagnostic of typhoid, but may be used for 

 confirmation, especially if the other diseases can be excluded. 



Prepare two fresh solutions: — 



(i) A saturated solution of sulphanilic acid in 5 per cent. HCl. 



(2) A 2|- per cent, solution of sodium nitrite. 



To 5 c.c. of urine, add an ecjual cjuantity of solution. 



(i) Then add a few drops of solution (2) and shake till frothy. 



Add ammonia till alkaline. 



If the liquid is port-wine colour and the froth is red, the reaction is 

 positive. 



In examining the f^ces use Conradi-Drigalski medium. 



The malachite green solution inhibits the coli growth and permits 

 that of the typhoid bacillus. 



In examining water, pass it through a filter; the organisms remain 

 on the filter candle; brush these off into the above medium. 



Alum will bring down a precipitate entangling the organisms, which 

 can then be treated as above. 



The typhoid bacillus is seldom found in the water that has caused 

 the disease, because fourteen days have elapsed since the patient par- 

 took of it and the organisms would have gone. 



DIFFERENTIAL DIAGNOSIS. 



In malaria, examine the blood for the parasites. 



In relapsing fever, the onset is sudden and the blood will show the 

 parasite. 



In undulant fever, do an agglutination test; cumulative evidence is 

 important. 



In yellow fever by sudden onset, albuminuria and black vomit. 



In typhus fever by sudden onset, mental symptoms appear early. 



In acute miliary tuberculosis, irregular fever, pulse and respiration 

 rapid, and is not dicrotic. 



In psittacosis, the specific bacilli can be isolated from the blood 

 and sick parrots will be about. 



In ulcerative endocarditis, by the murmurs and bacteriological 

 examination. 



