J. F. SHIRLAW AND N. S. SANKARNARAYAN 71
EXAMINATION FOR RICKETTSIAE OF NORMAL EYES OF SHEEP, GOATS AND HILL CATT
A flock of 36 sheep and a herd of 29 goats maintained at the Institute were
examined for evidence of ocular disease; with one exception, a goat affected with a unilateral, puru-
lent conjunctivitis, none showed any sign of active or latent conjunctivitis, keratitis or granulations
within the conjunctival membrane suggestive of rickettsial infection. Conjunctival films from 32
of the goats (including the case of purulent conjunctivitis) and 10 of the sheep were examined
for rickettsiæ. These were demonstrable within the conjunctival cells of every case. The extent
of the infection was variable; in a few cases, it was well marked, up to 60 per cent of conjunctival
cells harbouring the organism. In most cases, the organism was found in about 10 per cent of the
cells. In four goats, the infection was light and some search was necessary to demonstrate the orga-
nism. The extent of the infection within the cells was variable in individual films. Some cells were
densely packed with organisms (Plate I, fig. II), or they were present in clusters chiefly at the
margins of cells. Occasionally, a few small clumps were found extracellularly, apparently liberated
by the degeneration of infected cells. However, cell degeneration was not a conspicuous feature,
and even a massive cell infection seemed well tolerated. The morphology and staining affinity of
the organism conformed in detail to the classic description of R. conjunctivæ. Neutrophils were
occasionally seen in conjunctival films, and in a few cases Gram positive diplococci, many within
the phagocytes. In the solitary case of conjunctivitis, rickettsiæ were evident within the conjunc-
tival cells but this finding was overshadowed by an apparent bacterial infection. Whilst in some
films, neutrophils were present and apparently unaccompanied by bacteria, we did not consider that
such cells were a concomitant feature of the infection; and, when present, they appeared to have
no numerical relationship with the extent or intensity of the infection. In two of five hill cattle
examined, 30 per cent of the conjunctival cells were infected with rickettsiæ; in the remainder,
cell infection was light but definite. No morphological or tinctorial differentiation could be
established between the cattle and the goat organism.
EXAMINATION OF CASES OF HUMAN TRACHOMA
This was undertaken to compare the morphology and staining affinities of the goat organism
with the human one. Eight cases were selected for examination, one an early active infection, three
advanced and chronic, and four old and active. Rickettsiæ were determined within the conjunc-
tival cells in every case, the intensity of the infection varying in different cases, apparently inde-
pendently of the clinical activity of the condition. No distinction was possible between the human
and the goat forms of the parasite.
DISCUSSION
The scope of this investigation has been limited. Only on two occasions have we been notified
of cases of conjunctivitis in sheep and goats in India. Enquiries from Veterinary Investigation
Officers in the provinces (other than the Punjab) indicate that the disease has not been observed and
a careful survey is obviously called for. During the war years, a large number of goats and sheep
have passed through veterinary inspection at meat dehydration plants and army depots concerned
with the collection and dispatch of these animals for the supply of meat in the eastern theatre of war.
We had recently an opportunity of visiting one of these goats and sheep collecting depots where
among thousands of animals we saw no evidence of the disease. The traffic in goats and sheep
during the war years throughout northern India to these collecting depots has been so enormous
that the animals in the depots have been a fair random sample of the goat populations in this part
of India. We have had reports from the depots of every disease to which goats and sheep are subject;
yet, only on one occasion have we had a report of conjunctivitis. A diagnosis of rickettsial con-
junctivitis was made on examination of conjunctival films from a few cases, but this small outbreak
cleared up before a field investigation could be undertaken. We have also seen a few scattered cases
of keratitis among several thousand goats passing through a large meat dehydration plant in the
North West Frontier Province, but nothing in the nature of an outbreak of the disease; indeed,