1444 



UNDULANT FEVER 



general health begins to be unsatisfactory, and he seeks medical 

 advice. 



The Ambulatory Variety. — ^Apparently at times the organism may 

 produce such little effect that the infected person may be unaware 

 that he is suffering from any complaint, and may pursue his daily 

 vocation. Thus, out of 525 dock-hands examined by Shaw at Malta 

 for the serum reaction, 79 gave positive results; and of 22 tested, 

 9 contained the organism either in the blood or urine, or both. 



Complications. — Ulcers may, though rarely, occur in the small and 

 large intestine, and give rise to haemorrhage, while persistent vomit- 

 ing, diarrhoea, hyperpyrexia, pneumonia, pleuritis, effusion, and 

 cardiac failure all form serious complications. Orchitis is common. 

 As shown by Trotta, the micrococcus may occasionally acquire a 

 pyogenic action, and cases of suppurative localized periostitis have 

 been recorded similar to those seen in enteric infections. 



Sequelae. — Paralysis, neuritis, common in Cairo, wasting of 

 muscles, loss of memory, tremulousness, and neurasthenia are 

 possible sequelae. 



Diagnosis. — ^The principal clinical signs on which to base a 

 diagnosis are the prolonged undulant character of the fever, the 

 profuse sweatings, and the articular symptoms. 



Bacteriological methods of diagnosis should be always resorted 

 to whenever possible. The agglutination reaction, if the blood is 

 sufficiently diluted (at least i in 80), the test properly performed 

 and carried out, using a known and reliable strain of the germ, is, in 

 our experience, sufficiently certain. The agglutination test must 

 be performed in a dilution of at least i in 80, otherwise errors 

 in diagnosis will result. Bassett-Smith recommends a high dilution 

 (i in 1,000), but in our experience i in 80 is generally sufficient, 

 with a time-limit of thirty minutes. This reaction is said to last 

 for a very long time- — i.e., two to seven years. Birt and Lamb 

 have made this serum reaction the basis of prognosis, which is 

 considered to be unfavourable if continuously low, or rapidly alter- 

 ing from a high to a low figure. Agglutinins are present also in the 

 saliva (saliva-reaction of Polacci and others). Whenever possible 

 the agglutination test should be carried out in various dilutions, 

 to avoid results caused by a paradoxical reaction — viz., the possi- 

 bility of the serum agglutinating in high dilutions and not in low or 

 medium dilutions. In any doubtful case the blood should be inves- 

 tigated for the presence of M. melitensis, using nutrose media or 

 Castellani's dilution method, as in enteric infections (see p. 1390). 

 In case of a negative result, the examination should be repeated 

 at least three times at different periods of the disease. 



Nicolle and Conor consider that many of the errors are due, firstly, to 

 leaving the serum in contact with the clot, and state that either the blood 

 should be used at once or the serum separated from the clot; and, secondly, 

 in order to prevent obtaining positive reactions with non-undulant fever 

 serum, that sera, to be tested, should be heated to 56° C. for half an hour in 

 order to destroy the non-specific agglutinins, as first recommended by Negre 

 and Raynaud. 



