Analysis of HIV-1 load in blood, semen and saliva: evidence for different viral compartments in a cross-sectional and longitudinal study

OBJECTIVES

To quantify the HIV-1 load (measured as copies of viral RNA/ml using competitive reverse transcription-polymerase chain reaction) in blood, semen and saliva and to look for relationships between the viral burden, the clinical and immunological status and antiretroviral therapy.

METHODS

Peripheral blood, semen and whole saliva samples were collected from 26 anti-HIV-1-seropositive patients selected for a cross-sectional study. Nine of the 26 patients provided samples of the three biological fluids for a longitudinal study.

RESULTS

HIV-1 RNA was detected in 26 out of 26 samples of plasma, in 25 out of 26 samples of semen and in 24 out of 25 samples of saliva. The median number of HIV-1 copies in plasma was 14 817/ml (range: 167-254 880), in semen was 515/ml (range: 0-196 050) and in saliva was 162/ml (range: 0-72 080). The viral load in semen and in saliva was significantly lower than in plasma (P < 0.0001). The HIV-1 RNA levels in plasma and in saliva were correlated (P < 0.05), but levels in semen were not correlated with either plasma or saliva levels. The HIV-1 copy number in plasma was significantly higher in symptomatic patients than in asymptomatic subjects (P < 0.05). Plasma and saliva HIV-1 RNA levels were higher in subjects with a CD4+ cell count < 200 x 10(6)/l than in subjects with a CD4+ cell count > 200 x 10(6)/l (P < 0.05). The HIV-1 RNA load in either plasma, semen or saliva is not related to antiretroviral therapy.

CONCLUSIONS

The absence of a correlation between plasma and semen loads suggests that semen and blood are distinct viral compartments. Viral load in semen is not related to the clinical stage of HIV infection or to the CD4+ lymphocyte count. Consequently, HIV-1-infected subjects are potentially infectious at all stages of immuno-deficiency and adequate precautions must always be taken to prevent the sexual transmission of HIV.

Transmission of feline immunodeficiency virus in domestic cats via artificial insemination

The objective of this study was to determine whether semen from male domestic cats infected with feline immunodeficiency virus (FIV) can transmit virus to females. Twelve inseminations were performed by an intrauterine laparoscopic technique with fresh or cryopreserved electroejaculates from asymptomatic males chronically infected with the NCSU1 strain of FIV. Of six inseminations performed with fresh semen, three resulted in infection of queens, as indicated by seroconversion, expression of FIV gag provirus in peripheral blood leukocytes, and reduced peripheral CD4+/CD8+ T-lymphocyte ratios. None of the six inseminates with thawed cryopreserved semen resulted in infection. Two infected queens and one uninfected queen became pregnant. Virus was not evident in the seven offspring. We conclude that FIV can be transmitted horizontally by artificial insemination with fresh semen.

The use of a polymerase chain reaction assay for the detection of bovine herpesvirus 1 in semen during a natural outbreak of infectious bovine rhinotracheitis

Nasal swabs from two bulls at an artificial insemination (AI) station were submitted to our laboratory. The animals showed clinical signs of Infectious bovine rhinotracheitis (IBR), although the station was supposedly free of bovine herpesvirus 1 (BHV1). DNA of BHV1 was detected using a polymerase chain reaction (PCR). Subsequently nasal swabs from 100 animals that could have been in contact were submitted. BHV1 DNA was detected in swabs from 23 animals. Using the PCR, BHV1 could only be detected in a limited number of semen samples over a period of two months prior to the outbreak or two months after the outbreak. Also, not all animals that shed BHV1 from the nose harboured detectable BHV1 in the semen. Finally BHV1 was detected in the semen of one bull, approximately six weeks before seroconversion. Presently the PCR is being used as a means of quality control of fresh semen from bulls that are seropositive for BHV1. We are able to produce a result within 6 h after the semen samples have been submitted, allowing the AI-station manager to take measures before semen distribution in the event of a positive reaction. So far 11 out of 318 samples were shown to contain BHV1 DNA. In order to be able to interpret these results an interlaboratory comparative study is proposed. In countries endemically infected with BHV1 the PCR can be a cost-effective method to minimize the risk of transmitting virus by semen.

Intratesticular inoculation of avian leukosis virus (ALV) in chickens--production of neutralizing antibodies and lack of virus shedding into semen

In order to investigate the possibility of producing transgenic chickens by injection of avian leukosis virus-based vectors into testis, we have analyzed the infection rate of testicular cells following inoculation of Rous-associated virus type 1 (RAV-1) into the gonads of adult and 1-wk-old brown leghorn males. Viroproduction, neutralizing antibody production, and vital DNA presence in testis, blood, muscle, and semen were analyzed at various times after infection. Inoculation of RAV-1 into the gonads of adult males resulted in a low level of viroproduction in testis and blood, followed by the appearance of neutralizing antibody 2 or 3 wk later. Neither viroproduction in semen nor viral DNA presence in sperm were detected even though the infected chickens were found to produce RAV-1 in testis. One week after intratesticular inoculation of 1-wk-old males with RAV-1, a high level of viroproduction was found in blood and testis, and viral DNA was detected in gonadal cells. Further, by 6 wk after inoculation, the production of virus decreased in all tissues, viral DNA could not longer be detected in the testis, and neutralizing antibodies appeared in blood. All together these data show that it is possible to infect testicular cells by direct inoculation of RAV-1 in the testis, and that the immune response of both adult and young chickens seems to reduce this infection. Moreover, no evidence of spermatozoa infection was found; this result suggests that RAV-1 inoculation into testis may not induce genetic transmission of virus, and consequently would not be useful in the production of transgenic chickens.

Transmission of the South African asinine strain of equine arteritis virus (EAV) among horses and between donkeys and horses

Lateral and sexual transmission of EAV among horses and lateral transmission between donkeys and horses were attempted by experimental infection with the South African asinine strain. Clinical, immunological and virological responses were evaluated. All intramuscularly inoculated horses developed very mild clinical signs, were viraemic, shed virus from nasopharynx, and seroconverted. Lateral infection was demonstrated in one in-contact mare. Reinfection of two stallions by intranasal instillation was shown by virus recovery from buffy-coat cultures. After nasal instillation of virus, one stallion which did not become infected by in-contact exposure, showed slight serous nasal and ocular discharge, contained virus in a blood and nasopharynx and seroconverted. Attempts to transmit the virus from seropositive stallions to seronegative mares by breeding, were not successful; no virus was isolated from semen. All inoculated donkeys and three in-contact horses showed clinical signs consistent with an EAV infection. Although virus was isolated from donkey buffy-coat preparations and the nasopharynx, and they seroconverted, no virus was isolated from the horses, and they failed to seroconvert; it was assumed that their clinical signs were due to factors unrelated to EAV. The South African strain of EAV appears to be poorly transmissible to horses, supporting the findings of other field studies which indicate a widespread distribution and long-standing presence of the virus among South African donkeys, but a very restricted prevalence of seropositive horses.

Evaluation of the presence and risk of foot and mouth disease virus by commodity in international trade

Potential sources of foot and mouth disease (FMD) virus include semen from bulls, rams, goats and boars; embryos and ova from ruminants and pigs; meat and meat products and milk and milk products. The author discusses precautions to prevent the transmission of FMD via these commodities.

Equine arteritis virus: a review of clinical features and management aspects

Sero-epidemiological surveys have revealed that equine arteritis virus (EAV) is prevalent in most European countries. The virus causes sporadic cases of respiratory disease and abortion in horses, the incidence of which has increased in recent years. Mares and geldings eliminate virus after acute infection, but 30% to 60% of stallions become persistently infected. In these animals, EAV is maintained within the reproductive tract and is shed continuously in the semen. Persistent infection with EAV in stallions has no negative consequences for fertility but mares inseminated with virus-contaminated semen can have an acute infection. These mares shed large amounts of virus in respiratory secretions and urine, leading to lateral spread of the virus to other susceptible horses. Acute infection at later stages of gestation can lead to abortion. Effective control of the spread of EAV infection depends on the identification of virus-shedding stallions. Persistently infected stallions should not be used for breeding or should be bred only to seropositive mares. Mares bred to shedding stallions should be isolated from other animals for a period of 3 weeks following insemination to prevent the lateral spread of EAV.

A polymerase chain reaction (PCR) assay for the detection of bovine herpesvirus 1 (BHV1) in selectively digested whole bovine semen

A PCR assay for the detection of bovine herpesvirus type 1 (BHV1) DNA in selectively digested whole bovine semen was developed and evaluated. A brief treatment with proteinase-K was used to lyse free virus, virus present in non-sperm cells and virus adhering to the spermatozoa. Genomic bovine DNA was not released by this treatment. Primers and probes were based on the nucleotide sequence of the gD gene. BHV1 virus-spiked split samples were used as positive controls and the PCR products were detected by eye in ethidium bromide-stained agarose gels. Sequentially collected non-extended semen samples from experimentally infected bulls were used to compare this assay with virus isolation. Of a total of 162 ejaculates, 51 were found positive by virus isolation, whereas PCR detected BHV1 DNA in 73. PCR detected BHV1 DNA for a longer period after infection and reactivation. Apart from its superior sensitivity, this PCR assay also has the advantage of being a relatively simple procedure, providing results within 24 h.

Quantitation of human immunodeficiency virus type 1 RNA in cell free seminal plasma: comparison of NASBA with Amplicor reverse transcription-PCR amplification and correlation with quantitative culture

Human immunodeficiency virus type 1 (HIV-1) is transmitted by infected males in semen. However, the inoculum required for infection is unknown. The ability to collect such information will rely on the availability of reliable quantitative assays of HIV-1 in semen. We examined the comparative performance of NASBA and Amplicor Monitor RT-PCR in quantifying HIV-1 RNA in cell free seminal plasma from seropositive men and correlated the results obtained with viral titres measured by a seminal cell quantitative microculture (QMC) assay. Of samples analysed, 68% and 56% by both NASBA and RT-PCR contained measurable HIV-1 RNA, respectively. Amplification inhibition frequently affected RT-PCR but not NASBA. Excluding samples with complete RT-PCR inhibition, there was 90% qualitative concordance and a strong positive correlation (r = 0.86) of RNA levels measured by the two methods. Comparison of the concentration of HIV-1 RNA in seminal plasma samples, as measured by NASBA, with QMC viral titres indicated that RNA levels probably reflect the infectiousness of whole semen. NASBA is a reliable technique for quantitating HIV-1 RNA in seminal plasma and should become a valuable tool in the study of factors that influence the sexual transmission of HIV.

Latent BK virus infection and Kaposi's sarcoma pathogenesis

We have analyzed by PCR skin lesions from classic, endemic and AIDS-related Kaposi's sarcoma (KS), as well as from KS-derived cell lines, the presence of ubiquitous transforming viruses. BK virus (BKV), a transforming human papovavirus which has been associated with human tumors, was detected in 100% of KS skin lesions and 75% of KS cell lines. KS specimens contained a full-length, intact BKV early region, but minor rearrangements were observed in some tumors. BKV was also detected with a high prevalence (57-67%) in genital tissues and sperm, thus fulfilling the role of a sexually transmitted agent in KS. The closely related JC virus (JCV), which has never been associated with human malignancies, was present in 11-20% of KS specimens and was detected with a low prevalence (0-21%) in genital tissues and sperm. Simian virus 40 (SV40) was not detected in any KS lesions. Herpes simplex virus (HSV) DNA sequences were detected in 20-25% of KS lesions. Malignant human papillomavirus (HPV) types 16 and 18 and benign HPV types 6 and 11 were detected in KS specimens with a similar prevalence of 11-83%, suggesting that the presence of HPV-transforming sequences is not a specific trait of HPV interaction with KS tissue. Furthermore, JCV, SV40, HSV and HPV DNA sequences were not detected in KS cell lines, suggesting that these viruses are not associated to KS neoplastic cells in KS tissue. KS cell lines were also negative for DNA sequences of KS-HV, the novel herpesvirus detected in primary KS lesions. The constant association of BKV DNA with KS lesions and KS cell lines suggests that BKV-transforming functions may participate in the development of KS.

Kaposi's sarcoma-associated herpesvirus DNA sequences in prostate tissue and human semen

BACKGROUND

Sequences of novel herpesvirus, Kaposi's sarcoma-associated herpesvirus (KSHV), have been indentified in Kaposi's sarcoma tissue, but it is not known whether the virus is transmitted by sexual contact.

METHODS

Using the polymerase chain reaction (PCR), we searched for KSHV DNA sequences in ejaculates from 43 healthy men and tissue from the urogenital tract or prostate of 100 immunocompetent adults.

RESULTS

In an unblinded analysis, we identified KSHV DNA sequences in 2 of 20 tissue specimens from the urinary tract (10 percent; 15 men and 5 women), 3 of 46 specimens from the female genital tract (6.5 percent), 4 of 18 specimens from the glans or foreskin (22 percent), 7 of 16 specimens from the prostate (44 percent), and 30 or 33 ejaculates (91 percent). By contrast, such sequences were present in 1 of 18 samples of normal skin (5.5 percent) and 1 of 14 samples of peripheral-blood mononuclear cells (PBMCs; 7.1 percent). Ejaculates and PBMC samples from each of 10 study subjects were analyzed in a blinded, coded fashion, along with PBMCs and biopsy specimens of normal skin from 4 and 8 other patients, respectively. This analysis confirmed the presence of KSHV DNA sequences in semen. Viral DNA was not found in the sperm heads but was present in the fraction of the ejaculates that contained urothelial and other types of cells. Point mutations were found in PCR products amplified from both prostate tissue and sperm samples.

CONCLUSIONS

KSHV infects a large proportion of healthy adults and is probably transmitted by sexual contact.

Venereal shedding of ovine lentivirus in infected rams

OBJECTIVE

To assess shedding of ovine lentivirus (OvLV) in semen of infected rams with or without epididymitis.

DESIGN

Rams 1 and 2 were naturally infected with OvLV. Rams 3-6 were inoculated with OvLV strain 85/ 34. Ram 7 was inoculated with uninfected cell culture supernatant (OvLV-negative control). 14 weeks after OvLV inoculation, rams 1-3, 6, and 7 were inoculated with Brucella ovis into the epididymis. Ram 4 was a natural case of B ovis epididymitis, and ram 5 was left noninoculated (B ovis-negative control). Blood mononuclear cells (BMNC) and semen were collected between 0 and 44 weeks after OvLV inoculation.

ANIMALS

Seven 2- to 3-year-old rams.

PROCEDURE

Infective OvLV in BMNC and semen was determined by virus isolation and subsequent OvLV-DNA amplification by polymerase chain reaction (PCR). Bronchoalveolar lavage cells collected after death were used for DNA extraction and PCR amplification.

RESULTS

OvLV was detected in the semen of rams 3 and 6, but only after B ovis inoculation. OvLV was isolated consistently from BMNC of rams 3 and 6, but only occasionally from rams 1, 2, 4, and 5. Leukocytospermia was evident in every ejaculate of all B ovis-infected rams after infection. Semiquantitative PCR determination of OvLV DNA from bronchoalveolar lavage cells revealed the highest OvLV DNA load in rams 3 and 6.

CONCLUSIONS

Leukocytospermia and a high virus load in infected animals are important factors that determine shedding of OvLV in semen.

CLINICAL RELEVANCE

Dissemination of OvLV through contaminated semen could have important implications in the epidemiology and control of this infection.

Endogenous reverse transcription of human immunodeficiency virus type 1 in physiological microenviroments: an important stage for viral infection of nondividing cells

Endogenous reverse transcription (ERT) of retroviruses has long been considered a somewhat artificial process which only mimics reverse transcription occurring in target cells, as detergents or amphipathic peptides have classically been used to make the envelopes of retroviruses in these reaction systems permeable. Recently, several studies suggested that ERT of human immunodeficiency virus type 1 (HIV-1) might occur without detergent treatment. However, this phenomenon could be due to damage of the retroviral envelope during the process of virion purification or freezing and thawing. In this report, intravirion HIV-1 ERT, without detergent-induced permeabilization, is demonstrated to occur in the natural microenvironments of HIV-1 virions and is not caused by artificial processes. Therefore, this stage of the viral life cycle was termed natural ERT (NERT). The efficiency of NERT in HIV-1 virions was markedly augmented by several physiological substances in the extracellular milieu, such as polyamines and deoxyribonucleoside triphosphates. In addition, HIV-1 virions in seminal plasma samples harbored dramatically higher levels of full-length or nearly full-length reverse transcripts than virions isolated from peripheral blood plasma samples of HIV-1-seropositive men. When HIV-1 virions were incubated with seminal plasma samples, infectivity in initially nondividing cells was also significantly enhanced. Thus, we suggest that HIV-1 virions are actively altered by the extracellular microenvironment and that NERT may play an important role in viral infection of nondividing cells.

Genetic characterization of human immunodeficiency virus type 1 in blood and genital secretions: evidence for viral compartmentalization and selection during sexual transmission

To explore the mechanism of sexual transmission of human immunodeficiency virus type 1 (HIV-1), we compared HIV-1 gp120 sequences in longitudinal samples from five acute seroconvertors with those from their corresponding sexual partners (transmitters). We used a quantitative homoduplex tracking assay to compare the overall genetic composition of HIV-1 quasispecies in each transmission pair and to track the transmitted viruses during the acute and asymptomatic stages of HIV-1 infection. In the chronically infected transmitters, HIV-1 variants in genital secretions differed from those in blood and variants in cells differed from those in cell-free plasma, indicating remarkable sequence heterogeneity in these subjects as well as compartmentalization of the virus in different bodily sites. Conversely, two of five seroconvertors had only a few related variants and three of five harbored only one viral population, indicating that in these subjects the transmitted viruses were typically homogeneous. Transmitted viruses were evident in the donor's seminal plasma (one of five cases) and even more so in their seminal cells (three of five cases), suggesting that both cell-associated and cell-free viruses can be transmitted. In every pair studied, the transmitted variant(s) represents only a minor population in the semen of the corresponding transmitter, thereby providing evidence that HIV-1 selection indeed occurs during sexual transmission.

Human papillomavirus deoxyribonucleic acid and ribonucleic acid in seminal plasma and sperm cells

OBJECTIVE

To investigate the possible presence and expression of human papillomavirus viruses (HPV) in human plasma and sperm cells.

DESIGN

Controlled clinical study.

SETTING

A major medical center affiliated with a medical college.

PATIENTS

Twenty-four randomly selected patients who attended Fertility Clinics at the Chang Gung Memorial Hospital.

INTERVENTIONS

Specimens of semen were collected from volunteered patients

MAIN OUTCOME MEASURE

The presence of HPV types 16 and 18 DNA and RNA sequences were examined by polymerase chain reaction.

RESULTS

Human papillomavirus type 16 E6 and E7 DNA and RNA sequences were found in two and zero seminal plasma specimens, respectively, and in six and two sperm cells specimens, respectively. Deoxyribonucleic acid and RNA sequences of HPV type 18 were found in eight and two seminal specimens and in 11 and 5 sperm cells specimens, respectively.

CONCLUSION

These results seem to suggest that HPV cannot only infect human sperm cells, certain HPV genes are expressed actively in infected sperm cells. The virus-infected sperm cells conceivably can behave as vectors or carriers for the transmission of HPV, to sexual partner during sexual contact, to fetuses through fertilized eggs, or both.

Rapid detection of bovine herpesvirus 1 in the semen of infected bulls by a nested polymerase chain reaction assay

A nested polymerase chain reaction (PCR) assay was developed for the detection of bovine herpesvirus 1 (BHV-1) in bovine semen and compared with the virus isolation method. When extended semen, commonly used in the bovine artificial insemination industry, was inoculated with BHV-1, the PCR assay detected BHV-1 DNA in semen inoculated at 0.25-2.5 TCID50 per 0.5 mL. In contrast, the lower limit of detection for virus isolation was 250 TCID50 of BHV-1 inoculated in 0.5 mL of extended semen. These methods were also used to detect BHV-1 in the semen of four bulls which were experimentally infected with BHV-1. All infected bulls demonstrated balanitis at 3 d post-inoculation (DPI) and severe balanoposthitis at 4 DPI. BHV-1 was detected in raw semen by virus isolation and PCR at 2 DPI, before balanitis was evident. For virus isolation, the last day that BHV-1 was detected during primary infection was 7 DPI for two bulls and 9 and 11 DPI for the other two bulls. In contrast, PCR detected BHV-1 in the bulls' semen until 14 or 18 DPI. For individual animals, PCR detected BHV-1 during primary infection for at least 1-10 d longer than virus isolation. Reactivation of BHV-1 from latency without the presence of visible lesions was promoted twice by two series of 5 d dexamethasone injections. For the first series of dexamethasone treatments, a positive virus isolation result was obtained on the 5th d of treatment for only one bull. In contrast, two bulls demonstrated evidence of viral reactivation on this day by PCR. All bulls shed BHV-1 in semen on d 4 after dexamethasone treatment, as evidenced by positive virus isolation and PCR results. One bull was still PCR positive 13 d later. For the second series of dexamethasone treatments, a small amount of virus was isolated from semen collected on d 3 or 4 after treatment for two bulls but not from the other two bulls. In contrast, semen samples from all bulls were PCR positive for either or both of these 2 d. In total, from 80 semen samples, 45 were PCR positive and 26 were virus isolation positive. Thus, the PCR assay detected BHV-1 shedding in bulls earlier, more often, and for a longer duration, than did the virus isolation method.

[Detection and significance of HCV RNA in saliva, seminal fluid and vaginal discharge in patients with hepatitis C]

To investigate the transmission of HCV infection through family contact, we detected HCV RNS in body fluids (saliva, seminal and vaginal discharge) of 16 serum HCV RNA positive patients (including 7 men and 9 women) and in sera of their family members. The positive rates of HCV RNA in the body fluids were 31.25% (5/16) in saliva, 57.14% (4/17) in seminal fluid and 22.22% (2/9) in vaginal discharge, respectively. Among the family members in our series, all were negative for both anti-HCV and HCV RNA, despite two spouses positive for HCV RNA. This result strongly suggested the potential possibility of the transmission of HCV infection through the family contact.

Sensitive method for the detection of infectious HIV in semen of seropositive individuals

The aim of the study was to develop a sensitive culture method for the detection of HIV in semen. Antimicrobials were evaluated to suppress bacterial and fungal contamination of HIV cultures. Toxicity of seminal plasma was reduced using a short incubation of seminal fluid with culture cells. The detection rate was determined by adding known amounts of diluted primary virus isolates to uninfected cells. The sensitivity of the method was determined in a cohort of 33 HIV seropositive men. The use of a virus transport medium with high doses of antibiotics reduced contamination of HIV cultures. Toxicity of seminal plasma on culture cells was limited when seminal fluid was incubated with culture cells for only 90 min. Detection levels for cell-associated virus and cell-free virus from semen were 12 infected cells per ejaculate and 100 infectious units per milliliter of seminal fluid, respectively. Cell-associated HIV could be recovered from 18 semen samples of 33 HIV positive men (55%). Recovery of cell-free virus from seminal fluid was infrequent. It is concluded that the method is highly sensitive for the detection of HIV from semen. However, the recovery rate of infectious cell-free virus in seminal fluid from clinical samples is infrequent.

Bovine virus diarrhoea virus in semen from acutely infected bulls

The risk of spreading bovine virus diarrhoea virus (BVDV) from acutely infected animals to susceptible animals was investigated. Ten bulls from a herd with no previous history of BVDV were used. The bulls were demonstrated free from BVDV and such antibodies. Six of the bulls were inoculated intravenously with cytopathogenic virus, and 4 bulls were used as controls. Semen samples were collected during a period of 66 days after inoculation. The samples were examined for BVDV, and spermatological parameters were registered. Testes and epididymides were examined histologically post mortem. All inoculated bulls exhibited elevated temperatures between days 4 and 8 after inoculation, and BVDV antibodies were found in all of them on day 22. The control animals remained antibody negative. Non-cytopathogenic BVDV was isolated from seminal plasma from 2 bulls on day 7 after inoculation. Semen volume was significantly reduced from week 6 after inoculation. Percent abnormal sperm cells decreased in the same period. No significant differences were observed in sperm density or percentage of live spermatozoa. No pathological changes were found in the testes or epididymides.

Is Kaposi's-sarcoma-associated herpesvirus detectable in semen of HIV-infected homosexual men?

We explored a possible route of transmission of Kaposi's-sarcoma-associated herpes virus (KSHV) with nested and unnested PCR techniques. We looked for KSHV DNA sequences in semen of HIV-positive homosexual men and HIV-negative healthy semen donors. With unnested primers we found KSHV sequences in 21 of 33 (64%) homosexual men and in none of 30 healthy donors. With a nested PCR assay, 30 of 33 (91%) specimens from the homosexual men and 7 of 30 (23%) specimens from healthy donors had detectable KSHV sequences. Over 5 years of follow-up, 13 of 30 KSHV-positive homosexual men (43%) developed KS compared with none of the 3 KSHV-negative homosexual men.

Sexual and in-contact transmission of asinine strain of equine arteritis virus among donkeys

Two in a group of five naturally seropositive donkey stallions were found to shed equine arteritis virus (EAV) in their semen as demonstrated by virus isolation. Direct intramuscular inoculation of sonicated semen from one virus-shedding stallion (S3) caused clinical disease in two donkeys from which virus was recovered and in which seroconversion was detected. Sexual transmission was confirmed in two mares mated to S3 when after a febrile response during which EAV was isolated from huffy coats and nasal and ocular exudates, both mares were found to have seroconverted. In-contact transmission in a susceptible stallion was demonstrated after its exposure to a sexually infected mare. The 3' end of the asinine virus was amplified directly from donkey semen with EAV-specific primers, and its nucleotide sequence was found to be homologous to that of the prototype Bucyrus virus isolated from horses. These results indicate that EAV and its disease transmission are analogous in donkeys and horses.

Heterosexual HIV transmission

Most of the people now living with HIV acquired the infection through heterosexual intercourse. HIV transmission has been facilitated by (a) concomitant sexually transmitted diseases (STDs), (b) the presence of social conditions that create core groups who have frequent and numerous partners, (c) sexual practices associated with bleeding (i.e., trauma, sex during menses) as well as noncircumcision, (d) cervical ectopy, and (e) anal sex. HIV may be found both cell-free and as intracellular virus in genital tract secretion, and may be sexually transmitted through either mechanism. HIV titers in genital tract secretions vary by several logs between people and within individuals over time, being greatest just after seroconversion and with advanced immunosuppression, concomitant genital tract inflammation (including STDs), and decreasing (but not to zero) with antiretroviral therapy. The per-contact transmission efficiency rate is highly variable, ranging from > 3% to < 1 per thousand contacts, with male-to-female HIV transmission generally being more efficient than vice versa. Control of the heterosexual HIV epidemic will necessitate a multidisciplinary approach, utilizing direct biological approaches (e.g., culturally specific and behavioral interventions, as well as more fundamental community changes that decrease societal norms that augment unsafe practices.

Human immunodeficiency virus load. Quantitative assessment in semen from seropositive individuals and in spiked seminal plasma

OBJECTIVE

To establish criteria for the quantitation of the human immunodeficiency virus (HIV) in seminal plasma, seminal cells and the whole semen of HIV-infected individuals. The reverse transcription polymerase chain reaction (RT-PCR), DNA-PCR and semen HIV culture assays were standardized by testing seminal plasma spiked separately with serial dilutions of cell-free and cell-associated HIV stocks of known titers. The standardized assays were then used to assess the quantity of virus in the freshly collected seminal cells and seminal plasma.

RESULTS

Analysis of freshly collected peripheral blood mononuclear cells (PBMCs) and paired semen from HIV-seropositive men who had received antiviral drugs and/or immunemodulators indicated that HIV could be isolated from 42 of 55 (76%) samples of peripheral blood mononuclear cells (PBMCs) and 13 of 55 (24%) samples of ejaculates. Since no semen sample was culture positive in the absence of culturable HIV in PBMCs of the same individual, RT-PCR was 5-125 times more sensitive than cell cultures for the quantitation of HIV spiked in seminal plasma, freshly collected seminal fluid and whole semen. Further, HIV-RNA was detected in samples containing higher dilutions of virus from which HIV was not isolated by culture.

CONCLUSION

We conclude that cell-free HIV is present in excess of the culturable virus in all specimens tested and that the high sensitivity of HIV-RNA detection is useful for quantitation of the virus directly in seminal fluid, seminal cells and whole semen.

CD4+ cells in human ejaculates

Using flow cytometry, we studied the expression of the CD4 antigen within the different cells present in human ejaculate, both in spermatozoa and round cells. In all, 20 samples of semen were obtained from fertile males; in 11 of these, we detected the presence of leukocytes, using the peroxidase test. Swim-up was performed for the analysis of the spermatozoa. From our results it may be concluded that there is no expression of the CD4 antigen on the surface of human spermatozoa or on CD45- ejaculate cells (epithelial and germinal cells). However, we did detect the presence of the CD4 antigen on the surface of the leukocyte cells (CD45+). A better characterization of these CD45+ cells made it apparent that the CD4+ cells of ejaculate are composed of T lymphocytes (helper/inducer T lymphocytes) and monocytes. Thus we may conclude that human spermatozoa do not express the CD4 antigen, the cell surface receptor for human immunodeficiency virus. However, we did detect CD4+ T lymphocytes and CD4+ monocytes in semen.

Detection of feline immunodeficiency virus in semen from seropositive domestic cats (Felis catus)

Electroejaculates from experimentally infected domestic cats were evaluated for the presence of feline immunodeficiency virus (FIV). Virus was isolated from cell-free seminal plasma and seminal cells by cocultivation with a feline interleukin-2-dependent CD4+ T-cell line, in which productive infection was demonstrated by syncytium formation and FIV gag p26 antigen secretion. In addition, an 868-bp segment of the FIV gag provirus gene was identified in cocultured cells by PCR and Southern analysis. A 582-bp fragment of the FIV gag provirus genome was detected by nested PCR and Southern analysis in nonfractionated seminal cells and in sperm purified by a swim-up procedure. This is the first report describing the detection of replication-competent FIV in cell-free and cell-associated forms in domestic cat semen.

Rapid and sensitive detection of the bovine viral diarrhea virus genome in semen

A reverse transcription-polymerase chain reaction (RT-PCR) procedure was developed for the detection of bovine viral diarrhea virus (BVDV) in cell culture supernatant and in bovine semen. Several sets of primers, PCR conditions and extraction methods were examined to optimize the procedure. A set of primers designed to amplify a highly conserved portion of the p80 gene from BVDV (corresponding to NADL strain sequence from bp 6668 to 7107), was demonstrated to be the most effective. These oligonucleotide primers consistently amplify a 440-bp fragment from several non-cytopathic and cytopathic biotypes of BVDV. The viral origin of the PCR products was assessed by sequencing. The introduction of a Sephacryl S-400 chromatography step to remove seminal inhibitors prior to RNA extraction permitted RT-PCR detection of BVDV in raw and extended semen samples. A maximum sensitivity of 0.4 TCID50 was achieved with this method using RNA extracted from tissue supernatants. This RT-PCR assay may be a useful tool for the detection of BVDV in semen of persistently infected bulls.

Persistence of porcine reproductive and respiratory syndrome virus in serum and semen of adult boars

Four seronegative adult boars were intranasally inoculated with porcine reproductive and respiratory syndrome virus (PRRSV) isolate VR-2332. Serum and semen were collected 2-3 times weekly for over 100 days postinoculation (DPI). Serum samples were assayed for PRRSV by virus isolation (VI) and a polymerase chain reaction (PCR) and screened for antibodies to PRRSV using the indirect fluorescent antibody (IFA) and virus neutralization (VN) tests. Semen was assayed for PRRSV RNA by PCR. Virus and viral RNA was detected in the serum of all boars within 1 DPI by Vi and/or PCR. However, VI results indicated that viremia was transient and occurred from 1 to 9 DPI. Viral RNA was detected in serum from 1 to 31 DPI. In the acute stage of the infection, PRRSV RNA was detected in serum by PCR prior to the presence of viral RNA in semen. The PRRSV RNA was detected in semen as early as 3 DPI and persisted for 25 DPI in 2 of the boars and 56 and 92 DPI in the remaining 2 boars. Detection of PRRSV RNA in semen occurred 2-8 and 28-35 days prior to the detection of antibodies by IFA and VN, respectively. PRRSV was isolated from the bulbourethral gland of the boar that shed viral RNA in semen for 92 DPI. These results suggest that PRRSV RNA can be detected by PCR in boar serum and semen, and may persist for variable periods of time. Viremia and the serologic status of the boar are not adequate indicators of when PRRSV or PRRSV RNA is being shed in the semen. Preliminary findings also indicated that neither shipping stress nor reinoculation with homologous PRRSV resulted in viremia or viral RNA shedding in semen.

Human plasma enhances the infectivity of primary human immunodeficiency virus type 1 isolates in peripheral blood mononuclear cells and monocyte-derived macrophages

Physiological microenvironments such as blood, seminal plasma, mucosal secretions, or lymphatic fluids may influence the biology of the virus-host cell and immune interactions for human immunodeficiency virus type 1 (HIV-1). Relative to media, physiological levels of human plasma were found to enhance the infectivity of HIV-1 primary isolates in both phytohemagglutinin-stimulated peripheral blood mononuclear cells and monocyte-derived macrophages. Enhancement was observed only when plasma was present during the virus-cell incubation and resulted in a 3- to 30-fold increase in virus titers in all of the four primary isolates tested. Both infectivity and virion binding experiments demonstrated a slow, time-dependent process generally requiring between 1 and 10 h. Human plasma collected in anticoagulants CPDA-1 and heparin, but not EDTA, exhibited this effect at concentrations from 90 to 40%. Furthermore, heat-inactivated plasma resulted in a loss of enhancement in peripheral blood mononuclear cells but not in monocyte-derived macrophages. Physiological concentrations of human plasma appear to recruit additional infectivity, thus increasing the infectious potential of the virus inoculum.

Human cytomegalovirus (CMV) DNA in plasma reflects quantity of CMV DNA present in leukocytes

A quantitative DNA amplification assay for human cytomegalovirus (CMV) DNA has been used to evaluate the relationship between quantities of CMV DNA in plasma and those in infected leukocytes (WBC) from human immunodeficiency virus-infected patients. The target sequence for DNA amplification was a region of the immediate-early 1 gene of CMV. The quantitation assay uses an internal control that is coamplified with each patient sample DNA and contains a sequence for detection by colorimetric hybridization with the same bases, but in different order than in the CMV immediate-early 1 region used for hybridization of amplified patient sample DNA. Results showed that patients with CMV disease had more CMV DNA in both WBC and plasma than those without disease. However, in this study, copy numbers of CMV DNA in WBC were higher than those in plasma. The gB and gH variants were the same in plasma and WBC.

Virulence and genotype of a bovine herpesvirus 1 isolate from semen of a subclinically infected bull

A bovine herpesvirus 1 (BHV-1) isolate from the semen of a subclinically infected bull was administered to cattle by various routes to assess its virulence. Cattle that were artificially inseminated or inoculated intrapreputially did not develop clinical signs, but did transmit the virus to contact cattle. However, the isolate induced severe signs of rhinotracheitis and vulvovaginitis in cattle that were inoculated by the intravaginal, intranasal or intravenous routes, but did not infect the fetus. The isolate was therefore not of low virulence. Analysis with DNA restriction enzymes could not assign the isolate to either the BHV-1.1 or BHV-1.2 genotype.

Intermittent shedding of human immunodeficiency virus in semen: implications for sexual transmission

PURPOSE

We attempt to increase our understanding of human immunodeficiency virus (HIV) shedding in semen.

MATERIALS AND METHODS

We followed 16 seropositive men for up to 27 months by HIV cocultivation, with a subset evaluated using the polymerase chain reaction.

RESULTS

The proportion with at least 1 HIV positive semen culture increased from 3 of 16 subjects (19%) at visit 1 to 10 (63%) by visit 5. Overall, HIV was cultured from 25 of 114 specimens (22%). Shedding was intermittent for each of the 10 men with at least 1 positive culture and seminal shedding patterns were highly variable.

CONCLUSIONS

By culture and polymerase chain reaction, HIV is shed intermittently in the semen. If cultures are performed often enough most seropositive men shed HIV in the semen.

Detection of bovine herpesvirus 1 in the semen of experimentally infected bulls by dot-blot hybridisation, polymerase chain reaction and virus isolation

Two 18-month-old bovine herpesvirus 1 (BHV1)-seronegative bulls were inoculated experimentally with BHV1 via their prepuces. Semen collected at intervals was examined by optimised virus isolation, dot-blot hybridisation and the polymerase chain reaction (PCR) for detection of BHV1, and the infection was monitored serologically by using a virus neutralisation test. Antibodies were first detected 10 days after inoculation and were still present 40 days after inoculation. Semen collected from four to 40 days after inoculation was positive by PCR with Southern blot hybridisation whereas only the semen collected on day 4 was positive by dot-blot hybridisation, virus isolation and PCR with ethidium bromide staining. These results indicate that the bulls started to shed the virus in semen before they developed any detectable antibody. PCR with Southern blot hybridisation was the most sensitive of the three methods and detected virus for the longest period.

Detection of HCV RNA in serum and seminal fluid from HIV-1 co-infected intravenous drug addicts

The presence of hepatitis C virus (HCV) RNA in serum and seminal fluid was investigated in eleven drug addicts coinfected with HIV-1 and HCV. Serum and seminal fluid were taken from each patient at the same time point. HCV RNA was found in ten of the eleven serum samples tested, but only in one of the semen samples. No relationship was observed between CD4 cell counts, the stage of HIV infection, extent of liver damage and the presence of HCV RNA in serum and semen. The results indicate that HCV is not usually present in the semen and provide further evidence against sexual transmission as an important mode of transmission of HCV infection.

Inactivation of human immunodeficiency virus type 1 by the amine oxidase-peroxidase system

Human immunodeficiency virus type 1 (HIV-1) is rapidly inactivated by exposure to a naturally occurring antimicrobial system consisting of peroxidase, H2O2, and a halide. Among the potential sources of H2O2 is the amine oxidase system in which mono-, di-, and polyamines are oxidatively deaminated with the formation of H2O2. The polyamine spermine is present at exceptionally high concentrations in semen. We report here that spermine, spermidine, and, to a lesser degree, the synthetic polyamine 15-deoxyspergualin are viricidal to HIV-1 when combined with amine oxidase and myeloperoxidase. Antiviral activity required each component of the spermine-amine oxidase-peroxidase system and was inhibited by azide (a peroxidase inhibitor) and by catalase but not by superoxide dismutase. Heat treatment of catalase largely abolished its inhibitory effect. These findings implicate H2O2 formed by the amine oxidase system in the antiviral effect and raise the possibility that the polyamine-amine oxidase-peroxidase system influences the survival of HIV-1 in semen and in the vaginal canal.

Detection of porcine reproductive and respiratory syndrome virus in boar semen by PCR

Porcine reproductive and respiratory syndrome virus (PRRSV) causes a devastating disease in swine. The presence and transmission of PRRSV by boar semen has been demonstrated by using a swine bioassay. In this assay, 4- to 8-week-old pigs were inoculated intraperitoneally with semen from PRRSV-infected boars. Seroconversion of these piglets indicated the presence of PRRSV in semen. Seroconversion in gilts has also been demonstrated following artificial insemination with semen from PRRSV-infected boars. These methods of detecting PRRSV in boar semen are time-consuming, laborious, and expensive. The objective of this study was to develop a reliable and sensitive PCR assay to directly detect PRRSV in boar semen. Primers from open reading frames 1b and 7 of the PRRSV genome were used in nested PCRs. Virus was detected at concentrations as low as 10 infectious virions per ml in PRRSV-spiked semen. Specificity was confirmed by using a nested PCR and a 32P-labeled oligonucleotide probe. The primers did not react with related arteriviruses or other swine viruses. The PCR assay showed good correlation with the swine bioassay, and both methods were superior to virus isolation. To consistently identify PRRSV in boar semen, the cell fraction was separated by centrifugation at 600 x g for 20 min, a lysis buffer without a reducing agent (2-mercaptoethanol) was used, and nondiluted and 1:20-diluted cell fractions were evaluated by PCR. PRRSV was not reliably detected in the seminal plasma fraction of boar semen.

Bovine immunodeficiency virus in stud bull semen

Bovine immunodeficiency virus (BIV), a lentivirus, is prevalent in dairy and beef cattle in southeastern United States and may be associated with a lymphoproliferative disease. The mode(s) of BIV transmission are undefined. Because artificial insemination is a common practice in dairy production, contaminated stud semen could serve as an important source of infection if the virus is harbored in seminal fluids. To evaluate this possibility, we procured 11 cryopreserved semen specimens from a stud semen repository. Leukocytes were purified from the specimens, and the leukocyte DNA was used as template in a polymerase chain reaction procedure that targeted a 235-base pair, highly conserved domain of the BIV pol gene. The target sequence was amplified from the seminal leukocyte DNA of 9 of the specimens (82%), and nucleotide sequencing confirmed the BIV specificity of the fragment. This finding provides evidence that stud bull semen may serve as an important reservoir of BIV, suggesting the possibility that artificial insemination of dairy cows may have a major role in transmission and wide-spread dissemination of this bovine lentivirus.

First recorded outbreak of equine viral arteritis in the United Kingdom

Equine viral arteritis was diagnosed for the first time in the United Kingdom in 1993. The outbreak began on a non-thoroughbred stud in south Nottinghamshire and spread to five other premises through chilled semen used for artificial insemination and from acutely and subclinically infected mares returning home. The outbreak was contained on these six premises by means of voluntary movement restrictions. The most commonly observed clinical signs were typical: pyrexia with depression, and conjunctivitis with periorbital oedema; nasal discharge, and oedema of the distal limbs, prepuce and mammary glands were less common. The first mare to be covered by a recently imported stallion was the first animal to be affected. The mare was resident and no new mares had arrived on the stud during the previous five months. About 100 animals became infected during the outbreak, including three indigenous stallions. Equine arteritis virus was isolated from semen and heparinised blood samples and seroconversions were demonstrated by using the equine arteritis virus neutralisation test. Although the outbreak was contained, the free movement of animals within the European Union increases the possibility of infected stallions being introduced into the UK.

(S)-1-[3-hydroxy-2-(phosphonylmethoxy)propyl]cytosine (cidofovir): results of a phase I/II study of a novel antiviral nucleotide analogue

Cidofovir, (S)-1-[3-hydroxy-2-(phosphonylmethoxy)propyl]cytosine, is a novel antiviral nucleotide analogue with potent in vitro and in vivo activity against cytomegalovirus (CMV) and other herpesviruses. Thirty-one human immunodeficiency virus-seropositive patients with asymptomatic CMV excretion were evaluated in a phase I/II study with 2 regimens of cidofovir: cidofovir alone at doses of 0.5, 1.0, 3.0, or 10.0 mg/kg/week (20 patients) and cidofovir at 3.0, 5.0, or 7.5 mg/kg with concomitant oral probenecid, saline prehydration, extended dosing intervals, and drug interruption for proteinuria (19 patients). Prolonged and dose-dependent anti-CMV effect was observed with all cidofovir regimens > or = 3.0 mg/kg. The dose-limiting toxicity of cidofovir was dose- and schedule-dependent nephrotoxicity. Four of 20 patients had serum creatinine levels > or = 2.0 mg/dL after a mean cumulative exposure of 14.8 mg/kg cidofovir alone; however, none of 19 patients receiving the modified regimen had elevated creatinine (mean cidofovir exposure, 32.2 mg/kg). The clinical efficacy of cidofovir and its potential for cumulative nephrotoxicity needs further study in patients with end-organ CMV disease.