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PIROPLASMOSIS AMONG CATTLE IN THE 
MOMBERA DISTRICT, NYASALAND, 1909. 
By HUGH S. STANNUS, M.B. London. 
Medical Officer, Nyasaland. 
(With Plate XXVIII.) 
During the rainy season of 1908-9 an outbreak of disease among 
cattle occurred over a somewhat widespread area of the Mombera 
district, causing considerable losses in herds owned by natives. 
The district in question occupies a plateau lying at an elevation of 
from 3000 to 4000 feet, and inhabited by tribes owning a very large 
number of cattle. Some years ago they were very much reduced in 
numbers by an epidemic of Rinderpest, but they have since then 
rapidly increased and at the present time are estimated at about 
22,000 head. 
From information elicited from missionaries long resident in the 
district the disease would appear to have been observed periodically 
each year during the rains for many years past, occurring with varying 
incidence and mortality. 
I arrived in the district at the end of the rains, April 1909, and 
was only able to see a few recovering and chronic cases at that time. 
A small recrudescence of the sickness however occurred at and around 
Loudon during the months of October and November of the same year, 
and from these cases I was able to arrive at certain facts elucidating 
the nature of the disease. 
Epidemicity. The disease recurs annually during the rains, namely 
November to April, and occasionally cases may be met with as late as 
June. The incidence and mortality vary considerably in different 
years, in different parts of the district, and among herds in adjoining 
