Molecular Ecology and Natural History of Simian Foamy Virus Infection in Wild-Living Chimpanzees

Identifying microbial pathogens with zoonotic potential in wild-living primates can be important to human health, as evidenced by human immunodeficiency viruses types 1 and 2 (HIV-1 and HIV-2) and Ebola virus. Simian foamy viruses (SFVs) are ancient retroviruses that infect Old and New World monkeys and apes. Although not known to cause disease, these viruses are of public health interest because they have the potential to infect humans and thus provide a more general indication of zoonotic exposure risks. Surprisingly, no information exists concerning the prevalence, geographic distribution, and genetic diversity of SFVs in wild-living monkeys and apes. Here, we report the first comprehensive survey of SFVcpz infection in free-ranging chimpanzees (Pan troglodytes) using newly developed, fecal-based assays. Chimpanzee fecal samples (n = 724) were collected at 25 field sites throughout equatorial Africa and tested for SFVcpz-specific antibodies (n = 706) or viral nucleic acids (n = 392). SFVcpz infection was documented at all field sites, with prevalence rates ranging from 44% to 100%. In two habituated communities, adult chimpanzees had significantly higher SFVcpz infection rates than infants and juveniles, indicating predominantly horizontal rather than vertical transmission routes. Some chimpanzees were co-infected with simian immunodeficiency virus (SIVcpz); however, there was no evidence that SFVcpz and SIVcpz were epidemiologically linked. SFVcpz nucleic acids were recovered from 177 fecal samples, all of which contained SFVcpz RNA and not DNA. Phylogenetic analysis of partial gag (616 bp), pol-RT (717 bp), and pol-IN (425 bp) sequences identified a diverse group of viruses, which could be subdivided into four distinct SFVcpz lineages according to their chimpanzee subspecies of origin. Within these lineages, there was evidence of frequent superinfection and viral recombination. One chimpanzee was infected by a foamy virus from a Cercopithecus monkey species, indicating cross-species transmission of SFVs in the wild. These data indicate that SFVcpz (i) is widely distributed among all chimpanzee subspecies; (ii) is shed in fecal samples as viral RNA; (iii) is transmitted predominantly by horizontal routes; (iv) is prone to superinfection and recombination; (v) has co-evolved with its natural host; and (vi) represents a sensitive marker of population structure that may be useful for chimpanzee taxonomy and conservation strategies

What have we learned on mesons?

The author discusses pp annihilation processes involving resonances. These include omega /sup 0/; KK-threshold effects; pi /sub N/(1016), S*(1070); 'diffractive' mesons: A/sub 1/, B, C; KK pi -effects: D/sub 1/E/sub 1/F/sub 1/. (14 refs)

Hyperon-antihyperon production in pp interactions at 36 GeV/c leading to >or=3 particles in the final state

Results are presented on the properties of the pp interactions at 3.6 GeV/c leading to a hyperon or an antihyperon in final states with >or =3 particles from an experiment of 35 eV/ mu b sensitivity. Results of a multidimensional mass fit to each final state are given along with the cross sections, differential cross sections and polarization, where possible, for the hypercharge exchange reactions pp to Lambda Y* (1385), Lambda Y*(1405), Lambda Y*(1520), Sigma Y*(1385) and Sigma Y* (1520). (6 refs)

Study of the reactions pˉp→ΛˉΛ,ΛˉΣ0\bar{p}p \rightarrow \bar{\Lambda} \Lambda , \bar{\Lambda} \Sigma^{0} or Σ0ˉΛ,Σ+ˉΣ+\bar{\Sigma^{0}} \Lambda , \bar{\Sigma^{+}} \Sigma^{+} at 3.6 GeV/c

The reactions $\bar{p}p \rightarrow \bar{\Lambda} \Lambda , \bar{\Lambda} \Sigma^{0}$ or $\bar{\Sigma^{0}} \Lambda , \bar{\Sigma^{+}} \Sigma^{+}$ are studied at an incident momentum of 3.6 GeV/c in a 35.4 event/$\mu$ b experiment performed in the CERN 2m HBC. Total and differential cross sections are presented. The polarization of the hyperons is measured as a function of $t$ and for the reaction $\bar{p}p \rightarrow \bar{\Lambda} \Lambda$ the complete spin correlation matrix is given. (23 refs)

Observation of the 'forbidden' double charge exchange reaction pp to Sigma /sup -/ Sigma /sup -/ at 36 GeV/c

Data are presented which firmly establish the existence of the double charge exchange reaction pp to Sigma /sup -/ Sigma /sup -/ at 3.6 GeV /c. The forward cross section was found to be (5.9+or-1.1) mu b and the ratio of the 'forbidden' to 'allowed' forward cross-section is R= sigma ( Sigma /sup -/ Sigma /sup -/)/ sigma ( Sigma /sup +/ Sigma /sup +/)=0.09+or-0.02. (24 refs)