Horizontal Routes Research Articles

Study of children evacuation from pre‐school education institutions

AbstractThis paper deals with research into the evacuation of children from pre‐school educational institutions. The research was designed to determine possible values for their pre‐movement time and to thoroughly investigate the parameters of their movement along the emergency escape routes. All the stages of the research conducted are described including the preparation and arrangements for the actual observation studies and the collection of basic empirical data and their statistical treatment. This includes the analysis of the pre‐movement time for pre‐school educational institutions, a theoretical analysis for establishing the relationships between speed and density of flows of children of different age groups during their upward and downward movement on stairs, through door openings, along horizontal routes at a normal walking speed, and while running. It also includes the categorization of movement by a degree of emotional state and psychological abilities of those people involved. The use of the results obtained for evacuation planning under various conditions in pre‐school educational institutions is also discussed. Copyright © 2012 John Wiley & Sons, Ltd.

The effects of schistosomiasis on HIV/AIDS infection, progression and transmission.

The recent findings pertaining to the public health impact of schistosomiasis on the epidemiology of HIV/AIDS are summarized. Both empiric data and mathematical models support the hypothesis that schistosome infections lead to increased susceptibility to infection with HIV-1, a more rapid progression to disease through more vigorous viral replication and immunosuppression, and a higher likelihood of transmitting the infection to others through both vertical and horizontal routes. Different species of schistosome infection vary in the magnitude of their effects on these mechanisms with Schistosoma haematobium playing a greater role for increased susceptibility and transmission because of its association with urogenital disease. Schistosomiasis appears to be a cofactor in the spread and progression of HIV/AIDS in areas wherein both diseases are endemic; increased emphasis on treatment of schistosome infections in persons at risk of HIV/AIDS should be pursued.

Torque Teno Sus Virus in Pigs: an Emerging Pathogen?

The newly established family Anelloviridae includes a number of viruses infecting humans (Torque teno viruses) and other animal species. The ones infecting domestic swine and wild boar are nowadays named Torque teno sus viruses (TTSuV), which are small circular single-stranded DNA viruses highly prevalent in the pig population. So far, two genetically distinct TTSuV species are infecting swine. Both TTSuVs appear to efficiently spread by vertical and horizontal transmission routes; in fact, foetuses may be infected and the prevalence and viral loads increase by age of the animals. Detailed immunological studies on TTSuVs are still lacking, but it seems that there are no efficient immunological responses limiting viraemia. These viruses are currently receiving more attention due to the latest results on disease association. Torque teno sus viruses have been circulating unnoticed in pigs for a long time, and even considered non-pathogenic by themselves; there is increasing evidence that points to influence the development of some diseases or even affect their outcome. Such link has been mainly established with porcine circovirus diseases.

The center location problem with equal weights in the presence of a probabilistic line barrier

A B S T R A C T In this paper, a single facility centre location problem with a line barrier, which is uniformly distributed on a given horizontal route in the plane is proposed. The rectilinear distance metric is considered. The objective function minimizes the maximum expected barrier distance from the new facility to all demand points in the plane. An algorithm to solve the desired problem is proposed where a mixed integer nonlinear programming needs to be solved. The proposed model of this paper is solved using some already existed benchmark problem in the literature and the results are compared with other available methods.

Acquisition ofRickettsia felisby Cat Fleas During Feeding

Evidence for horizontal routes of transmission for Rickettsia felis has come from detection of R. felis infection in vertebrates and multiple blood-feeding arthropods; however, infection of cat fleas, Ctenocephalides felis, during blood feeding has not been demonstrated. In this study, the ability of cat fleas to acquire R. felis through an infectious blood meal with subsequent vertical transmission was examined. Utilizing an artificial feeding system, Rickettsia-naive fleas were exposed to R. felis-infected blood meals and monitored for subsequent infection at weekly intervals for 4 weeks. At 7 days postexposure (dpe) ~52% of fleas successfully acquired rickettsiae and R. felis DNA; rickettsial transcript and DNA was detected in cat flea feces. Quantitative real-time polymerase chain reaction determined that both the R. felis infection load and R. felis infection density was significantly greater in fleas assessed at later time points. Although a persistent R. felis infection was detected in adult fleas, R. felis infection was not observed in F(1) progeny. This study demonstrates that cat fleas are able to acquire R. felis infection from an infectious blood meal and will serve as a model to examine R. felis transmission between arthropod and vertebrate hosts.

Horizontal transmission of deformed wing virus: pathological consequences in adult bees (Apis mellifera) depend on the transmission route

Recent reports on a steady decline of honeybee colonies in several parts of the world caused great concern. There is a consensus that pathogens are among the key players in this alarming demise of the most important commercial pollinator. One of the pathogens heavily implicated in colony losses is deformed wing virus (DWV). Overt DWV infections manifested as deformed-wing syndrome started to become a threat to honeybees only in the wake of the ectoparasitic mite Varroa destructor, which horizontally transmits DWV. However, a direct causal link between the virus and the symptom 'wing deformity' has not been established yet. To evaluate the impact of different horizontal transmission routes, and especially the role of the mite in the development of overt DWV infections, we performed laboratory infection assays with pupae and adult bees. We could demonstrate that pupae injected with DWV dose-dependently developed overt infections characterized by deformed wings in adult bees, suggesting that DWV, if transmitted to pupae by the mite, is the causative agent of the deformed-wing syndrome. The OID(50) (overt infection dosage) was approximately 2500 genome equivalents. Injecting more than 1×10(7) DWV genome equivalents into adult bees also resulted in overt infections while the same viral dosage fed to adult bees only resulted in covert infections. Therefore, both infection of adult bees through DWV-transmitting phoretic mites and infection of nurse bees through their cannibalizing DWV-infected pupae might represent possible horizontal transmission routes of DWV.

Lack of evidence for vertical transmission of SAV 3 using gametes of Atlantic salmon, Salmo salar L., exposed by natural and experimental routes

Pancreas disease (PD) is an important cause of losses in farmed salmonids in Norway, the United Kingdom and Ireland. As the spread of salmonid alphavirus (SAV), the causal agent, to naïve populations is of major concern to the farming industry, it is important to uncover the transmission routes of the virus. This study was conducted to investigate the potential for vertical transmission of SAV subtype 3. Progeny of broodstock with signs of late-stage PD and persistent RT-PCR signals for SAV were followed from fertilization to smoltification in an experimental facility. Fertilized ova were either not disinfected or taken through one of three different disinfection regimes. Also, ova and milt from uninfected broodfish from a different population were exposed to a cell-cultured strain of SAV 3 immediately before fertilization to simulate a viraemic phase in parent fish. A group of uninfected controls were also included in the study. Fertilized ova from bath exposed and negative control groups were double disinfected. Following fertilization, experimental fish went through a normal freshwater phase. However, fry were stressed at first feeding to enhance replication of possibly latent virus. Smoltification was induced by an artificial light regime, and experimental fish were followed to the late smoltification phase. Selected samples were investigated by real-time RT-PCR for SAV, by histology for evidence of PD and by serology for neutralising antibodies against SAV. All analysed samples of progeny were negative. This result shows that SAV 3 is not readily transmitted vertically from parents to offspring. Additional negative PCR results from salmon sampled in commercial hatcheries support these findings. Also, recent studies have shown that risk factors for the horizontal transmission route explain the vast majority of PD outbreaks in Norway. It is concluded that if it happens at all, vertical transmission is of minor importance in the spread of SAV 3.

Acetic Acid Bacteria, Newly Emerging Symbionts of Insects

Recent research in microbe-insect symbiosis has shown that acetic acid bacteria (AAB) establish symbiotic relationships with several insects of the orders Diptera, Hymenoptera, Hemiptera, and Homoptera, all relying on sugar-based diets, such as nectars, fruit sugars, or phloem sap. To date, the fruit flies Drosophila melanogaster and Bactrocera oleae, mosquitoes of the genera Anopheles and Aedes, the honey bee Apis mellifera, the leafhopper Scaphoideus titanus, and the mealybug Saccharicoccus sacchari have been found to be associated with the bacterial genera Acetobacter, Gluconacetobacter, Gluconobacter, Asaia, and Saccharibacter and the novel genus Commensalibacter. AAB establish symbiotic associations with the insect midgut, a niche characterized by the availability of diet-derived carbohydrates and oxygen and by an acidic pH, selective factors that support AAB growth. AAB have been shown to actively colonize different insect tissues and organs, such as the epithelia of male and female reproductive organs, the Malpighian tubules, and the salivary glands. This complex topology of the symbiosis indicates that AAB possess the keys for passing through body barriers, allowing them to migrate to different organs of the host. Recently, AAB involvement in the regulation of innate immune system homeostasis of Drosophila has been shown, indicating a functional role in host survival. All of these lines of evidence indicate that AAB can play different roles in insect biology, not being restricted to the feeding habit of the host. The close association of AAB and their insect hosts has been confirmed by the demonstration of multiple modes of transmission between individuals and to their progeny that include vertical and horizontal transmission routes, comprising a venereal one. Taken together, the data indicate that AAB represent novel secondary symbionts of insects.

Microsatellite typing and avidity analysis suggest a common source of infection in herds with epidemic Neospora caninum-associated bovine abortion

Neosporosis is an important cause of reproductive failure in cattle worldwide. Two different abortion patterns associated with Neospora caninum infection have been observed in cattle herds: endemic and epidemic abortion outbreaks. The endemic pattern is characterized by an abortion problem in a herd persisting for several months or years, and is assumed to be caused by reactivation of a chronic infection. In epidemic outbreaks, abortions concentrate within a short period of time, most likely due to a recent point source exposure of naïve animals to N. caninum. The aim of the study was to characterize five N. caninum-associated epidemic abortion outbreaks in Germany by serological and molecular techniques, including a p38-avidity-ELISA and typing of N. caninum in clinical samples by multilocus-microsatellite analysis. DNA extracts from the brain of 18 N. caninum infected fetuses from epidemic abortion outbreaks were characterized using 10 N. caninum-microsatellite markers. Nested-PCR protocols were developed to amplify the marker regions MS1B, MS3, MS5, MS6A, MS6B, MS7, MS12 and MS21 from clinical samples for subsequent analysis by capillary electrophoresis. Microsatellites MS2 and MS10 were analyzed by previously reported sequencing techniques. Most dams which had aborted showed a low-avidity IgG response to the N. caninum p38-antigen, and in three of the five studied herds, the majority of the dams at risk, which had not aborted, had also low-avidity responses suggesting that infection with N. caninum had recently occurred in most animals. A common microsatellite pattern prevailed in all fetuses from each individual epidemic outbreak. This pattern was unique for each herd. Although the number of epidemic abortion outbreaks analyzed was limited, the observation of a common microsatellite pattern, accompanied by a low-avidity IgG response against N. caninum in the dams, supports the hypothesis of a recent infection from a common point source. The genetic diversity of N. caninum observed among these outbreaks may indicate that not a particular N. caninum genotype but the horizontal infection route determines the occurrence of epidemic abortions.

Retroviruses in Wild-Born Semi-Captive East African Sanctuary Chimpanzees (Pan troglodytes schweinfurthii)~!2010-01-28~!2010-03-24~!2010-04-20~!

Information on retroviruses infections in great apes is scarce, especially for apes kept in sanctuaries throughout Africa. To investigate the prevalence of retroviruses and possible transmission of different retroviruses originating from chimpanzees of different origin (Uganda, Congo and Rwanda), 38 wild-born captive orphan chimpanzees residing in a sanctuary on Ngamba Island were analyzed for retroviral infections. Samples from sanctuary chimpanzees were analyzed using enzyme-linked immunoassays and polymerase chain reactions (PCR). Viruses were characterized by phylogenetic analysis. All chimpanzees were negative for antibodies against Simian Immunodeficiency Virus (SIV) and Simian T-cell Leukemia Virus (STLV). However, 28/38 (73%) chimpanzees were positive to Simian Foamy Virus (SFV) by analysis of a 425-bp DNA segment obtained by PCR using generic integrase primers homologous to highly conserved portions of the polymerase gene. Phylogenetic analysis of SFV sequences obtained in this study formed four sub clusters within the specific SFV P. t. schweinfurthii clade with significant variability among the new SFVs strains. We provide evidence of on-going cross-transmission of SFV among chimpanzees within the sanctuary mostly likely through horizontal routes. We propose to test all chimpanzees introduced into sanctuaries for retroviral and other infections. This will help avoid the spread also of pathogenic viruses in captive populations.

The rectilinear distance Weber problem in the presence of a probabilistic line barrier

This paper considers the problem of locating a single facility in the presence of a line barrier that occurs randomly on a given horizontal route on the plane. The objective is to locate this new facility such that the sum of the expected rectilinear distances from the facility to the demand points in the presence of the probabilistic barrier is minimized. Some properties of the problem are reported, a solution algorithm is provided with an example problem, and some future extensions to the problem are discussed.

Lateral Intent Error’s Impact on Aircraft Prediction

The lateral deviation between the air traffic automation’s known horizontal route of flight and the actual aircraft position is due to the typical navigation and surveillance errors, as well as the larger atypical errors that are mainly caused by purposeful changes in the route of flight that are not updated. The paper presents large data analyses of the ground automation systems of the United States and Europe, indicating errors from 20 to 30 nautical miles are common, while airborne Australian and more samples in the United States had errors from 100 to 800 times smaller. Further analysis illustrated the direct impact these errors have on safety critical separation management functions. It was concluded that airborne derived data via Automatic Dependent Surveillance Contract reports offer a major opportunity to improve the ground-based automation functions.

Assessments of Fitness Effects by the Facultative Symbiont Rickettsia in the Sweetpotato Whitefly (Hemiptera: Aleyrodidae)

Abstract The sweet potato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), harbors several bacterial symbionts, including the obligate primary symbiont Portiera aleyrodidarum and the facultative secondary symbionts Arsenophonus, Cardinium, Fritschea, Hamiltonella, Rickettsia, and Wolbachia. The roles of these symbionts are yet unknown. In this study, we tested for possible effects of one symbiont, Rickettsia, on some fitness parameters of B. tabaci (biotype B) by comparing whiteflies that carry this symbiont to whiteflies that do not. Preadult development of Rickettsiacarrying whiteflies was faster, but all the other parameters that were measured: longevity, total number of progeny, sex ratio, and nymphal survivorship did not differ significantly. Estimates of the intrinsic growth rate (r) were almost identical for the two groups. Cross-mating between clefts-carrying and Rickettsia-free whiteflies provided no evidence for cytoplasmic incompatibility. Vertical transmission of Rickettsia was found to be nearly complete. Our results do not clearly identify a selective advantage that would explain the high prevalence of Rickettsia in B. tabaci populations, thus, other fitness parameters and horizontal transmission routes are suggested and discussed.

Quantification of pigeon circovirus in serum, blood, semen and different tissues of naturally infected pigeons using a real-time polymerase chain reaction

The development of a real-time polymerase chain reaction (PCR) based on SYBR Green chemistry is described for the quantification of pigeon circovirus (PiCV) DNA in various samples. Plasmid containing a fragment of the PiCV genome was used to create a standard curve and to estimate the viral DNA copies in analysed samples. Both primers were designed in highly conserved regions to avoid false negatives, and amplified a 139-base-pair amplicon. When the amplifications were performed in the presence of cellular DNA extracted from PCR-negative liver, bursa and spleen samples, the detection limits were respectively 20, 20 and 60 copies of genome per milligram of tissue. These limits were 10, 160 and 25 copies/µl for control blood, sera and semen, respectively. For cloacal swab, the detection limit was 200 copies. The assay showed a linear detection over a six-log range (R 2>0.99) and displayed reliable inter-assay and intra-assay reproducibility. Application of the test to sera samples indicated the presence of the virus in Belgium in 1991, 6 years before PiCV infections were histologically diagnosed. Testing of samples from pigeons with “young pigeon sickness” showed that the viral loads were high in the bursa of Fabricius (up to 2.07×109copies/mg), the liver (up to 2.88×108copies/mg) and spleen (up to 5.57×108copies/mg). For liver, the viral load was significantly higher in sick pigeons than in apparently healthy pigeons. Detection of high quantities of PiCV DNA (up to 1.6×109copies/µl) in the sera or blood of some young healthy pigeons indicated that the viral load in this sample type would not be useful as predictive indicator of disease. This work also showed that PiCV DNA can be detected in relatively large amounts in semen (up to 1.0×107copies/ejaculate) and cloacal swabs (up to 3.6×1010copies/swab), confirming that PiCV may be transmitted by vertical and horizontal routes.

Regulatory integration of horizontally-transferred genes in bacteria.

Horizontal transfer of genetic material is a fact of microbial life and bacteria can obtain new DNA sequences through the processes of conjugation, transduction and transformation. This offers the bacterium the possibility of evolving rapidly by importing new genes that code for new traits that may assist in environmental adaptation. Research in this area has focused in particular on the role of horizontal transfer in the dissemination through bacterial populations of genes for resistance to antimicrobial agents, including antibiotics. It is becoming clear that many other phenotypic characteristics have been acquired through horizontal routes and that these include traits contributing to pathogenesis and symbiosis. An important corollary to the acquisition of new genes is the problem of how best to integrate them in the existing gene regulatory circuits of the recipient so that fitness is not compromised initially and can be enhanced in the future through optimal expression of the new genes.

Seroprevalence of HHV-8, CMV, and EBV among the general population in Ghana, West Africa

BackgroundHuman herpesvirus 8 (HHV-8), cytomegalovirus (CMV) and Epstein-Barr virus (EBV) are prevalent in Africa, but less common elsewhere and the modes of transmission are still subject to debate. Generally, they rarely cause disease in the immunocompetent host but are highly oncogenic when associated with immunosuppression. Although the high prevalence of HHV-8, CMV and EBV has been well documented in Africa, such data are sparse from Ghana.MethodsSerum samples from 3275 HIV-seronegative healthy blood donors and 250 HIV-AIDS patients were tested for antibodies specific for HHV-8, CMV and EBV by IgG ELISA assays. Differences in seropositivity rates by gender and age were evaluated using the Chi-square test with Yates correction.ResultsOf the 3275 HIV-seronegative healthy blood donors tested, 2573 (78.6%) were males and 702 (21.4%) were females, with ages ranging from 18 to 65 years (median 32.6; mean 31.2; mode 30). Of the 250 HIV-AIDS patients tested, 140 (56%) were males and 110 (44%) were females, with ages ranging from 17 to 64 years (median 30.8; mean 30.3; mode 28). Among the HIV-seronegative healthy blood donors, overall seroprevalence of HHV-8, CMV and EBV was 23.7%, 77.6% and 20.0%, respectively. Among the HIV-AIDS patients, overall seroprevalence of HHV-8, CMV and EBV was 65.6%, 59.2% and 87.2%, respectively. The seroprevalence of HHV-8 (p < 0.005) and EBV (p < 0.001) was statistically significantly higher in HIV-AIDS patients compared to HIV-seronegative healthy blood donors. There was no statistically significant difference (p = 0.24) between CMV seroprevalence in HIV-AIDS patients and HIV-seronegative healthy blood donors. Age and gender were not independent determinants (p > 0.05) for all three infections among HIV-seronegative healthy blood donors and HIV-AIDS patients in Ghana.ConclusionThe results presented herein indicate that HHV-8, CMV and EBV infections are hyperendemic in both HIV-seronegative and HIV-seropositive Ghanaians, and suggest primarily a horizontal route of transmission of these three viral infections in Ghana.

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.

Hepatitis B and C in children

Chronic infection with hepatitis B affects nearly 350 million individuals worldwide and is the leading cause of hepatocellular carcinoma and liver cirrhosis. Universal infant immunization has decreased rates of HBV infection, although transmission continues to occur via vertical (mother-to-child) and horizontal (sexual, parenteral and household) routes. Treatments are now available for children with chronic HBV infection, but appropriate selection of those most likely to respond to treatment is important. Interferon alpha and lamivudine are currently approved in the US for the treatment of children older than 2 years of age who have chronic HBV infection. Hepatitis C infection affects almost 170 million individuals worldwide. Of individuals exposed to HCV, 60-80% develop chronic hepatitis, and 10-15% of those chronically infected develop cirrhosis within several decades. No vaccine exists for HCV; therefore, prevention of parenteral transmission is important. A high index of suspicion is essential for the diagnosis of HCV infection given its silent clinical presentation. Appropriate evaluation of infected individuals is warranted when considering their suitability for therapy. Interferon alpha and ribavirin, used in combination, are currently approved in the US for the treatment of children older than 3 years of age with chronic HCV infection.

Persistence ofMycobacterium aviumsubspecies paratuberculosis in rabbits: the interplay between horizontal and vertical transmission

SummaryParatuberculosis (Mycobacterium aviumsubspeciesparatuberculosis; Map) is a widespread and difficult disease to control in livestock populations and also has possible links to Crohn's disease in humans. Rabbits (Oryctolagus cuniculus) have been identified recently as the key wildlife species in terms of paratuberculosis transmission to the wider host community. Here, we test the hypothesis thatMapcan persist in rabbit populations for extended periods of time in the absence of any external source of infection.A spatially explicit stochastic simulation model of a generic host–disease interaction was developed to quantify the interplay between vertical and horizontal routes of transmission needed for the persistence ofMapin rabbit populations and to test the hypothesis. The model was parameterized based on empirical studies on rabbit population dynamics and on rabbit‐to‐rabbit routes ofMaptransmission.Predictions from the model suggest that any disease with susceptible–infected (SI) dynamics without disease‐induced mortality can persist within a rabbit population in the absence of vertical transmission, providing the horizontal transmission coefficient, β, is greater than approximately 0·012. The inclusion of any vertical transmission reduces the value of β that is necessary for infection to persist.Paratuberculosis persists in rabbit populations at all values of the horizontal and vertical transmission parameters in the range estimated from the field data and in many cases at all values within 95% confidence intervals around this range. The persistence ofMapinfection in rabbit populations in the absence of external sources of infection suggests that they may act as a reservoir of infection for sympatric livestock.Synthesis and applications.Our findings, in combination with the ubiquitous distribution of rabbits in the United Kingdom and elsewhere, suggests that ifMapbecomes established in rabbit populations they are likely to provide widespread and persistent environmental distributions of infection and thus disease risk to livestock and potentially humans. Where local rabbit populations are infected they should be included in any future paratuberculosis control strategies. Because eradication of rabbits is often not a realistic option, control strategies should include reducing interspecific transmission risk from rabbits to livestock via the faecal–oral route.

Horizontal and vertical transmission of viruses in the honey bee, Apis mellifera

The most crucial stage in the dynamics of virus infections is the mode of virus transmission. In general, transmission of viruses can occur through two pathways: horizontal and vertical transmission. In horizontal transmission, viruses are transmitted among individuals of the same generation, while vertical transmission occurs from mothers to their offspring. Because of its highly organized social structure and crowded population density, the honey bee colony represents a risky environment for the spread of disease infection. Like other plant and animal viruses, bee viruses use different survival strategies, including utilization of both horizontal and vertical routes, to transmit and maintain levels in a host population. In this review, we explore the current knowledge about the honey bee viruses and transmission routes of bee viruses. In addition, different transmission strategies on the persistence and dynamics of host–pathogen interactions are also discussed.