In humans, senescence increases susceptibility to viral infection. However, comparative data on viral infection in free-living non-human primates—even in our closest living relatives, chimpanzees and bonobos (Pan troglodytes and P. paniscus)—are relatively scarce, thereby constraining an evolutionary understanding of age-related patterns of viral infection. We investigated a population of wild eastern chimpanzees (P. t. schweinfurthii), using metagenomics to characterize viromes (full viral communities) in the faeces of 42 sexually mature chimpanzees (22 males, 20 females) from the Kanyawara and Ngogo communities of Kibale National Park, Uganda. We identified 12 viruses from at least four viral families possessing genomes of both single-stranded RNA and single-stranded DNA. Faecal viromes of both sexes varied with chimpanzee age, but viral richness increased with age only in males. This effect was largely due to three viruses, salivirus, porprismacovirus and chimpanzee stool-associated RNA virus (chisavirus), which occurred most frequently in samples from older males. This finding is consistent with the hypothesis that selection on males for early-life reproduction compromises investment in somatic maintenance, which has delayed consequences for health later in life, in this case reflected in viral infection and/or shedding. Faecal viromes are therefore useful for studying processes related to the divergent reproductive strategies of males and females, ageing, and sex differences in longevity.

This article is part of the theme issue ‘Evolution of the primate ageing process'.

在人类中，衰老会增加对病毒感染的易感性。然而，关于自由生活的非人类灵长类动物——即使是我们最近的近亲、黑猩猩和倭黑猩猩（Pan troglodytes和P. paniscus）——中病毒感染的比较数据相对稀少，从而限制了对与年龄相关模式的进化理解。病毒感染。我们调查了东部野生黑猩猩种群 ( P. t. schweinfurthii)，使用宏基因组学来表征来自乌干达基巴莱国家公园的 Kanyawara 和 Ngogo 社区的 42 只性成熟黑猩猩（22 只雄性，20 只雌性）粪便中的病毒组（完整的病毒群落）。我们从至少四个具有单链 RNA 和单链 DNA 基因组的病毒家族中鉴定出 12 种病毒。两性的粪便病毒组随着黑猩猩年龄的变化而变化，但病毒的丰富度仅在雄性中随着年龄的增长而增加。这种影响主要是由于三种病毒，唾液病毒、porprismacovirus 和黑猩猩粪便相关 RNA 病毒（chisavirus），它们最常见于老年男性的样本中。这一发现与以下假设一致，即选择雄性进行早期繁殖会损害对体细胞维持的投资，从而延迟了对生命后期健康的影响，在这种情况下，反映在病毒感染和/或脱落。因此，粪便病毒组可用于研究与男性和女性不同的生殖策略、衰老和寿命性别差异相关的过程。

这篇文章是主题问题“灵长类动物衰老过程的演变”的一部分。