We investigate host-pathogen dynamics and conditions for coexistence in two models incorporating frequency-dependent horizontal transmission in conjunction with vertical transmission. The first model combines frequency-dependent and uniparental vertical transmission, while the second addresses parasites transmitted vertically via both parents. For the first model, we ask how the addition of ver...

The evolution of virulence was studied in a virus subjected to alternating episodes of vertical and horizontal transmission. Bacteriophage f1 was used as the parasite because it establishes a debilitating but non-fatal infection that can be transmitted vertically (from a host to its progeny) as well as horizontally (infection of new hosts). Horizontal transmission was required of all phage at s...

As much as vertical transmission of microbial symbionts requires their deep integration into the host reproductive and developmental biology, symbiotic lifestyle might profoundly affect bacterial growth and proliferation. This review describes the reproductive oddities displayed by bacteria associated - more or less intimately - with multicellular eukaryotes.

A tuberculosis (TB) transmission model involving migrant workers is proposed and investigated. The basic reproduction number R0 is calculated, and is shown to be a threshold parameter for the disease to persist or become extinct in the population. The existence and global attractivity of an endemic equilibrium, if R0 > 1, is also established under some technical conditions. A case study, based ...

CaliciNet, the outbreak surveillance network for noroviruses in the United States, was launched in March 2009. As of January 2011, twenty state and local health laboratories had been certified to submit norovirus sequences and epidemiologic outbreak data to CaliciNet. During the network's first year, 552 outbreaks were submitted to CaliciNet, of which 78 (14%) were associated with foodborne tra...

We report the pregnancy outcome and clinical and laboratory findings in infants born to women with chikungunya infection during pregnancy. There was evidence of vertical transmission and poor pregnancy outcome in some cases.

Potato virus Y group C isolates (PVYC) have been characterized according to biological, molecular and genetic criteria. Two genetic strains, PVYC1 and PVYC2, were identified on the basis of genetic distances (among them and other PVY strains), host range (ability or inability to infect pepper), MAb response (ELISA recognition with MAb 10E3) and coat protein processing site. Some characteristics...

although the infection of different animals and non-human primates with other members of anelloviridae have already been reported there is no report about infection of animals with torque teno midi virus/small anellovirs (ttmdv/sav). the aim of this study was to detect the virus in domestic village chickens. blood samples were collected from 79 domestic village chickens in isfahan. blood sample...

Symbiotic bacteria are commonly associated with cells and tissues of diverse animals and other organisms, which affect hosts' biology in a variety of ways. Most of these symbionts are present in the cytoplasm of host cells and maternally transmitted through host generations. The paucity of paternal symbiont transmission is likely relevant to the extremely streamlined sperm structure: the head c...