Poliomyelitis and skeletal asymmetry in Gombe chimpanzees

Evaluation of poliovirus antibody titers in orally vaccinated semi-captive chimpanzees in Uganda

BACKGROUND

To understand immunological responses in chimpanzees vaccinated with live-attenuated vaccine (oral polio vaccine; OPV), serum neutralizing antibodies against poliovirus types 1, 2, and 3 were investigated over time.

METHODS

The neutralizing antibody titers against poliovirus types 1, 2, and 3 were determined by microneutralization test using 100 ID(50) of poliovirus types 1, 2, and 3 (Sabin strains).

RESULTS

Neutralizing antibodies against poliovirus types 1, 2, and 3 were detected in 85.7%, 71.4%, and 65% of the serum from 42 chimpanzees tested 9 years post-vaccination. The neutralizing antibody titers in chimpanzees were similar to the documented levels in human studies as an indicator of vaccine efficacy.

CONCLUSIONS

This study reveals persistence of neutralizing antibodies in chimpanzees for at least 9 years after vaccination with OPV. This first study in chimpanzees provides useful information for the evaluation of the success of vaccination with OPV in other captive apes.

The dangers of multi-male groupings: trauma and healing in cercopithecoid monkeys from Cameroon

This study examines the potential linkage between social organization and trauma in a sample of cercopithecids from Cameroon. Skeletal trauma is described in a museum collection of eight sympatric monkey species. Macroscopic analysis was carried out on a total of 139 complete skeletons of mangabeys, colobines and guenons. Species in multi-male groups were found to have higher fracture frequencies than those in uni-male groups. These higher frequencies may be related to intra-specific male-male aggression; however, similarities in fracture patterning between males and females in multi-male groups suggest that other factors may be involved. Although fracture etiology may not be identified with certainty, this study suggests that predation may indirectly be a cause of traumatic injuries in those species of cercopithecid monkeys displaying multi-male social organizations. The data presented also highlight the utility of museum collections as an additional resource in analyses of primate behavior, demonstrating that behavioral information does not die when the animal does.

Role of Nonbehavioral Factors in Adjusting Long Bone Diaphyseal Structure in Free-ranging Pan troglodytes

Limb bones deform during locomotion and can resist the deformations by adjusting their shapes. For example, a tubular-shaped diaphysis best resists variably-oriented deformations. As behavioral profiles change during adulthood, patterns of bone deformation may exhibit age trends. Habitat characteristics, e.g., annual rainfall, tree density, and elevation changes, may influence bone deformations by eliciting individual components of behavioral repertoires and suppressing others, or by influencing movements during particular components. Habituated chimpanzee communities provide a unique opportunity to examine these factors because of the availability of morphological data and behavioral observations from known-age individuals inhabiting natural habitats. We evaluated adult femora and humeri of 18 female and 10 male free-ranging chimpanzees (Pan troglodytes) from communities in Gombe (Tanzania), Mahale Mountains (Tanzania), and Taï Forest (Côte d'Ivoire) National Parks. We compare cross sections at several locations (35%, 50%, 65% diaphyseal lengths). Community comparisons highlight different diaphyseal shapes of Taï females relative to Mahale and Gombe females, particularly in humeral diaphyses. Age trends in diaphyseal shapes are consistent with reduced activity levels in general, not only reduced arboreal activity. Age-related bone loss is apparent among community females, but is less striking among males. Community trends in diaphyseal shape are qualitatively consistent with ranked annual rainfall at localities, tree density, and elevation change or ruggedness of terrain. Habitat characteristics may contribute to variation in diaphyseal shape among chimpanzee communities, much like among modern human groups, but verification awaits further rigorous experimental and comparative analyses.

Skeletal pathology in Pan troglodytes schweinfurthii in Kibale National Park, Uganda

The ecological pressures shaping chimpanzee anatomy and behavior are the subject of much discussion in primatology and paleoanthropology, yet empirical data on fundamental parameters including body size, morbidity, and mortality are rare for wild chimpanzees. Here, we present skeletal pathology and body size data for 20 (19 crania, 12 postcrania) chimpanzees (Pan troglodytes schweinfurthii) from Kibale National Park, Uganda. We compare these data with other East African populations, especially Gombe National Park. Estimated body size for Kibale chimpanzees was similar to other East African populations and significantly larger than Gombe chimpanzees. The high rates of trauma and other skeletal pathology evident in the Kibale chimpanzee skeletons were similar to those in the Gombe skeletal sample. Much of the major skeletal trauma in the Kibale skeletons was attributable to falls, although other pathologies were noted as well, including apparent injuries from snares, degenerative arthritis, and minor congenital abnormalities.

Comparison of storage methods for reverse-transcriptase PCR amplification of rotavirus RNA from gorilla (Gorilla g. gorilla) fecal samples

Detection of enteric viral nucleic acids in preserved gorilla fecal specimens was investigated using reverse transcription polymerase chain reaction (rt-PCR). A commercially available viral RNA extraction kit was used to isolate nucleic acids from captive gorilla fecal samples seeded with rotavirus and stored in ethanol, formalin, a commercial RNA preservation solution, guanidine thiocyanate buffer (GT), and samples dried in tubes containing silica gel. Nucleic acids were extracted at 1, 7, 70 and 180 days and used for rt-PCR amplification of specific rotavirus RNA sequences. Successful rt-PCR amplification of the target product varied according to storage conditions, and storage time. Only samples stored in GT gave 100% positive results at 180 days. It is recommended that fecal samples be collected in GT for viral RNA analysis.

Skeletal evidence of probable treponemal infection in free-ranging African apes

The prevalence and patterning of inflammatory lesions of the skeleton were investigated in samples of chimpanzees (Pan troglodytes troglodytes) and gorillas (Gorilla gorilla gorilla) curated at the Powell-Cotton Museum, Birchington, UK. One hundred and two chimpanzees (42 adults and 60 subadults) and 126 gorillas (50 adults and 76 subadults) comprise the samples. Twenty per cent of chimpanzees and 14% of gorillas were affected with a disseminated inflammatory skeletal condition caused by infection. The lesions appear to have originated as localized patches of new bone deposition on the surface of long bones and to have progressed to infection of the bone cortex and marrow. Although female prevalence of involvement exceeds that of males in both species, the differences are not statistically significant. The age distribution of affected animals indicates that the disease began in some animals as early as 2 yr of age. Given the skeletal and demographic prevalence and patterning of the lesions as well as the ecology and behavior of these animals, the most likely diagnosis of the condition is a yaws-like treponemal infection.

Parasitism of asymmetrical pelvic phenotypes in stickleback

Subtle departures from bilateral symmetry in morphological traits result from environmental and genetic stresses and may signal an inferior genetic background. Because one correlate of an inferior genome is reduced resistance to infection, such asymmetry may provide a phenotypic signal of susceptibility to parasitism. I tested this hypothesis in a population of threespine stickleback (Gasterosteus aculeatus) with cestode and nematode infections and bilateral asymmetry of the pelvis. Seventeen percent of the fish had an asymmetrical pelvis and, of these, 78% had greater expression on the left side; this directionality suggests a genetic influence. Females had consistently greater left-side asymmetry than did males. The incidence of total infection (all parasite species) in the largest adult fish (> 60 mm body length) was greater in asymmetrical phenotypes, and this occurred in both sexes and for each parasite species (Schistocephalus solidus, Cyathocephalus truncatus, Eustrongylides spp.), even when multiple-species infections were excluded. Contrary to prediction, however, in juvenile fish (< 20 mm) and yearlings (20–40 mm) but not subadults and adults (40–60 mm), asymmetrical phenotypes had significantly lower infection rates than symmetrical fish. This pattern occurred in both sexes, but the extent of the association varied over the 14 years of sampling. Consequently, if the directional asymmetry of the pelvis is under genetic control, asymmetry would be favoured during early ontogeny but selected against during the adult stages. The data support the hypothesis that asymmetry is a phenotypic signal of parasitism, but the unexpected bidirectionality of the association within a single population suggests increased complexity of the processes coupling asymmetry and genetic background.