HIV InfectionsHelicobacter InfectionsHelicobacter pyloriTime FactorsCytomegalovirus InfectionsBacterial InfectionsRisk FactorsImmunoglobulin GPolymerase Chain ReactionAntibodies, ViralChlamydophila pneumoniaeAnti-Bacterial AgentsPrevalenceParvovirus B19, HumanHIV-1Virus DiseasesDisease SusceptibilityRespiratory Tract InfectionsImmunocompromised HostPregnancy Complications, InfectiousMolecular Sequence DataInfectionPregnancyAcute DiseaseDNA, ViralAntibodies, BacterialCytomegalovirusHelminthiasisHepatitis CDisease Models, AnimalEnzyme-Linked Immunosorbent AssayInfant, NewbornCells, CulturedSeroepidemiologic StudiesErythema InfectiosumChlamydia InfectionsTumor Virus InfectionsCase-Control StudiesCell LineViral LoadPapillomavirus InfectionsRNA, ViralEnterovirus InfectionsChronic DiseaseCytokinesParvoviridae InfectionsImmunoglobulin MRetrospective StudiesIncidenceMice, Inbred C57BLHost-Pathogen InteractionsOpportunistic InfectionsIntestinal Diseases, ParasiticVirus ReplicationLungCD4-Positive T-LymphocytesProspective StudiesFatal OutcomeHerpes SimplexTreatment OutcomePicornaviridae InfectionsMutationAIDS-Related Opportunistic InfectionsInterferon-gammaChlamydophila InfectionsT-LymphocytesFecesAsymptomatic InfectionsHepatitis BBase SequenceImmunity, InnateMice, Inbred BALB CAntiviral AgentsEnterovirusCoinfectionPapillomaviridaeViremiaDisease ReservoirsHerpesviridae InfectionsReverse Transcriptase Polymerase Chain ReactionAge FactorsRecurrenceLymphocyte ActivationPneumonia, ViralSeasonsSpleenRNA, MessengerCD4 Lymphocyte CountCD8-Positive T-LymphocytesAcquired Immunodeficiency SyndromeMacrophagesDisease OutbreaksUrinary Tract InfectionsPhylogenyHepacivirusZoonosesCohort StudiesSuperinfectionAnti-Infective AgentsTumor Necrosis Factor-alpha