Robert E. Kuntz

Parasites of baboons (Papio doguera (Pucheran, 1856)) captured in kenya and tanzania, east Africa

With the recent impetus and a growing concern for the subhuman primates a number of investigations have been initiated to explore more carefully the general biology of this group of vertebrates. Considerable attention has been directed toward extensive studies in the basic biology and biomedical aspects of the baboon. As already indicated by an extensive bibliography on baboons (SHILLING 1964) this animal has been one of the more commonly recognized and widely used primates. The potential use of Papio as a model for medical research has been the topic of the First International Symposium on the Baboon (VAOTBORO 1965). Although there are numerous references (MYERS and KUNTZ 1965) to parasites and pathological manifestations due to infection, reports on the parasites of baboons taken from their natural habitat are few and far between. Since the majority of parasitological reports have been based upon hosts held in captivity for varying periods it has not been feasible to judge the normal or natural parasitism characteristic of this primate. In a broad program outlined by the Department of Microbiology, SFRE, investigations have been initiated to evaluate the parasite and general microfaunal populations in wild as well as in captive animals. The present report is based on parasites and other intestinal microfauna obtained from or detected in a series of 13 baboons captured in Kenya and Tanzania in 1964. Additional information relative to sites of collection, general ecological aspects of the overall study and preliminary findings in the field of microbiology have been described by KALTEa et al. (1966).

Parasites of the Kenya baboon: Arthropods, blood protozoa and helminths (Kenya, 1966)

Although there is an impressive list of parasites for baboons, a recent compilation (MYERS & KUNTZ, 1965) has stressed the great need for parasitological studies in the field where the baboons occur. A large proportion of records for baboons, as well as for other primates, is based upon an examination of hosts in which the parasite fauna has been greatly modified by varying periods in captivity. The desirability of survey type studies to provide more accurate host-parasite data on natural infections is obvious. The present report is one part of multidiscipline investigations conducted by the Division of Microbiology and Infectious Diseases of the Southwest Foundation for Research and Education (SFRE) in Kenya early in 1966. It is a continuation and expansion of parasitological studies on the Kenya baboon taken in different localities in 1964 (KALraR et al., 1965; KVNTZ & MYERS, 1966). Hosts were examined in three areas representing different ecological habitats.

Calcification of the bladder and papillary tumours of the bladder and ureters in gibbons (Hylobates lar) infected with Schistosoma haematobium (Iran)

Many species of nonhuman primates have been employed to find parasite-definitive host combinations which would allow for investigations on different aspects of schistosomiasis haematobia. Gibbons (Hylobates lar), exposed to moderate numbers of Schistosoma haematobium cercariae, have demonstrated some of the basic features of schistosomiasis haematobia in man. Calcification in schistosomiasis haematobia is variable. Radiologically evident calcification of the bladder was noted in one gibbon. Radio-opaque areas in the bladder corresponded to dense deposits of calcified eggs observed on histological examination. Thus, it seems, bladder calcification, thought to be a later complication of schistosomiasis, can develop fairly rapidly. One of two gibbons killed 11 months after infection had small papillary transitional cell tumours in both ureters. The other had papillary transitional cell tumours covering most of the urinary bladder surface. No invasion of muscle by tumour was present and no metastases were seen.

Primate Cysticercosis:Taenia hydatigena in Kenya Vervets (Cercopithecus aethiops Linnaeus, 1758) and Taiwan Macaques (Macaca cyclopis Swinhoe, 1864)

Unless there is an opportunity to correlate the larval stages of taeniids with adults obtained from the feeding of appropriate definitive hosts, an attempt to identify encysted forms from intermediate hosts frequently meets with frustration. Although there is much conflicting information on the larval forms (types as well as their taxonomy) of the taeniids, none surpasses that of the cestode Taenia hydatigena which seems to be a cosmopolitan parasite that occurs in different forms in a number of intermediate hosts. Confusion among related species of taeniid cestodes and the importance of larval types has been emphasized recently in a critical study by EscrI and SELF (1965). The parasites herein described and pictured were obtained from primates in two widely separated localities. Three of approximately 240 Kenya vervets (Cercopithecus aethiops LINNAEUS, 1758) examined routinely for studies in microbiology in San Antonio were infected. Two hosts possessed two cysts each and a third had only one well developed cysticercus. Two cysticerci were found in each of two of 57 Taiwan macaques (Macaca cydopis SWlNHOE, 1864) examined in a broad range survey of the parasites of vertebrates of Taiwan, Republic of China. Although there is considerable confusion regarding the features of these larval stages, the number of hooks (28 to 32), their arrangement on the rostellum the size

Resistance of capuchin monkeys to reinfection with Schistosoma haematobium.

Capuchin monkeys were resistant to reinfection with Schistosoma haematobium one year after exposure to 500 cercariae, but worms in these monkeys continued to produce normal numbers of eggs. Monkeys were apparently completely refractory to reinfection when challenged 2-5 years after an initial exposure of 1000 to 2000 cercariae.

Zoophilic schistosomiasis on Taiwan: Reestablishment of Schistosoma japonicum subsequent to drastic alteration of habitats by flood.

Drastic alterations in the habitats of Schistosoma japonicum in the enzootic area of Taiwan practically eliminated the parasite in the focus studied. Observations over a period of several years allowed a comparison of the status of host-parasite relationships before and after interruption of the parasite cycle by natural causes. Although excessive flooding reduced the snail (Oncomelania formosana) population and the parasite infection in definitive hosts (lower vertebrates) to near nil, Oncomelania populations returned to near normal after approximately 1 year, followed by appearance of infection in rodents. An unusual compensation in biological productivity seemed to allow for rapid reestablishment of the schistosome cycle after abnormal circumstances had placed the parasite-snail-definitive host associations in jeopardy. The inability of the Taiwan strain of Schistosoma japonicum to infect man has been a biological curiosity for years, especially since the island is geographically located near the center of a broad arc of the Orient in which schistosomiasis is a disease of great concern. Confinement to a few small areas, plus a number of other biological factors, separate the species on Taiwan from a morphologically similar parasite designated by the same name in Japan, mainland China, the Philippines, and other areas of Southeast Asia. Continuation of the cycle under adverse conditions has added to the uniqueness of the schistosome situation. S. japonicum continues to propagate itself in spite of very low biotic potentials and other uncertain circumstances relating to zoophilic schistosomiasis on the island. During the past decade Dr. H. F. Hsii and associates (1952, 1962) have elucidated the various peculiarities which differentiate the Taiwan species from others in the Far East. Their early field observations revealed the low rates of infection in Oncomelania formosana in most of the localities studied in Pu-yen Hsiang (township) near Chang-hua. Subsequent observations over a Received for publication 29 March 1965. * Research task MR. 005.09-1601.3, Bureau of Medicine and Surgery, Navy Department. This study was supported in part by funding under Public Law 480, Section 104 (c). The opinion and assertions herein are those of the author and are not to be construed as official or reflecting the views of the Navy Department or Naval Service at large. period of several years in the same area by the present author have similarly indicated rates of infection so low in the snail and lower mammalian hosts that continuation of the cycle appears all but impossible. Factors such as the seasonal reduction of infection rates in mollusks during the winter months, unpredictable drying or man-imposed alterations of snail habitats for parts of the year, intensive rodent control campaigns which eliminate a number of the infected vertebrate hosts, etc., in the enzootic areas, add to the precariousness of host-parasite associations. Hairston (1962) has presented the problems relating to population ecology and has graphically illustrated the mathematical complexities to be surmounted for maintenance of the schistosome cycle in the Philippines, where conditions, though regulated by a multitude of natural variables, probably are more favorable for parasite survival than in Taiwan. During the course of field studies, a natural disaster altered the majority of schistosome habitats and practically eliminated the infection on the west-central coastal plain of Taiwan. For approximately 1 week the S. japonicum habitats were covered as a result of flooding after excessive rains. This occurred in August (1959), the season at which parasite transmission potentials are at their height. Biological activities relating to the parasite cycle within habitats were greatly reduced and temporarily suspended as the rich, well-cultivated and irrigated, alluvial plain of Pu-yen was submerged in 2 to 6 ft of fast-flowing