Viral Infection in Endometritis: Is There an Important Role or Not?

Chronic endometritis (CE) is a frequent pathological condition that is defined as localized inflammation in the endometrium. Some adverse fertility consequences such as recurrent miscarriage and failure of implantation are associated with chronic endometritis. On the one hand, inflammation plays an important role in the pathogenesis of endometritis, and on the other hand, the role of viral infections in inducing inflammation can make this review strongly attractive and practical. We set out to provide an overview of viral infections as a potential etiology of CE pathophysiology through the alteration of an endometrial microenvironment and its association with infertility. To the best of our knowledge, this is the first review to demonstrate the role of viral infection in chronic endometritis, and whether or not infection ultimately plays a role..

Presence of gammaherpesvirus BoHV-4 in endometrial cytology samples is not associated with subclinical endometritis diagnosed at artificial insemination in dairy cows.

In the past, bovine herpesvirus 4 (BoHV-4) has been suggested to be associated with metritis and endometritis. However, not many field studies investigated the association between BoHV-4 and subclinical endometritis (SCE). In the present study, the association between the intrauterine presence of BoHV-4 and SCE diagnosed during artificial insemination (AI) was examined on two dairy farms in Belgium. An immunoperoxidase monolayer assay (IPMA) and an enzyme-linked immuno sorbent assay (ELISA) were used to screen the serum for anti-BoHV-4 antibodies. A SYBR green based one step real time qPCR was used to detect and quantify BoHV-4 (ORF20) in nasal, uterine and vaginal samples collected at AI. A reverse transcription qPCR (RT-qPCR) was used to detect mRNA (gB) as proof of a productive BoHV-4 infection. BoHV-4 was detected in 39.4% (farm A)/23.8% (farm B) of the nasal samples, 48.5% (farm A)/19.0% (farm B) of the uterine samples and 51.5% (farm A)/42.9% (farm B) of the vaginal samples. Active replication was only detected in farm A in 38.5% of the BoHV-4 positive nasal samples and in 5.9% positive cases of the vaginal samples. The prevalence of SCE diagnosed at AI was 45.5% and 42.9% in farm A and farm B, respectively. The presence of SCE was associated with a reduced pregnancy outcome at artificial insemination (AI) (P＜0.001). The occurrence of SCE at AI was not associated with the presence of latent or productive BoHV4 infections in the uterus nor in the vagina and nose (P＞0.05).

Histologic Changes Associated With Placental Separation in Gilts Infected with Porcine Reproductive and Respiratory Syndrome Virus.

The placenta is a vital organ providing the developing fetus with nutrient and gas exchange, thermoregulation, and waste elimination necessary for fetal development, as well as producing hormones to maintain pregnancy. It is hypothesized that fetal pig death in porcine reproductive and respiratory syndrome may be attributed to pathology of the maternal-fetal interface leading to premature placental separation. This study was designed to evaluate the chronologic progression of porcine reproductive and respiratory syndrome virus (PRRSV)-induced lesions at the maternal-fetal interface, with particular focus on placental separation in experimentally challenged third-trimester gilts. Fifteen gilts were inoculated with a virulent strain of PRRSV-2 on gestation day 86 ± 0.4. On multiple days postinoculation, 3 gilts along with 1 sham-inoculated control per time point were euthanized, and uterine and fetal placental tissues corresponding to each fetus were collected for histopathologic evaluation. The presence of any fetal lesion was 23 times more likely in compromised (meconium-stained and decomposed) compared with viable fetuses ( P < .001). In PRRSV-infected gilts, endometritis was more severe than placentitis, and the severity of endometrial inflammation and vasculitis increased progressively from 2 to 14 days postinoculation. Neither placental vasculitis nor a chronologic progression in the severity of placental detachment was observed. Severe placental detachment was more frequently present in PRRSV-infected compared with noninfected samples and was most significantly associated with placental inflammation, compared with other uterine lesions, viral load, or termination day. The results of this study suggest that placental separation by itself is not sufficient to significantly compromise fetal viability in reproductive porcine reproductive and respiratory syndrome.

Impact of Bovine Herpesvirus 4 (BoHV-4) on Reproduction.

Bovine herpesvirus 4 (BoHV-4) is increasingly considered as responsible for various reproductive troubles. This virus infects blood mononuclear cells and displays a specific tropism for vascular endothelia, mammary tissue, endometrium and foetal tissues. Viral multiplication can be reactivated by corticosteroids or stress, both factors present at calving. BoHV-4 has been isolated in a large variety of clinical cases, primarily metritis, vaginitis and mastitis, but also endometritis, abortion and orchitis. Its impact on reproductive performance has been suggested by several epidemiological studies: seroprevalence against BoHV-4 is higher in aborted females and in repeat breeders. Nevertheless, its intrinsic pathogenic power seems low, symptoms developing only when BoHV-4 cooperates with bacteria: within the uterus or mammary gland. BoHV-4 is rather currently considered as a cofactor for the development of an inflammatory reaction initiated by bacteria.

Detection of bovine herpesvirus type 4 antibodies and bovine lymphotropic herpesvirus in New Zealand dairy cows.

AIM: To detect the presence of bovine herpesvirus (BoHV) type 4 in New Zealand dairy cows with clinical metritis. METHODS: Serum samples taken from 92 dairy cows with clinical metritis, each from a different farm, were tested for the presence of antibodies against BoHV-4 using a commercially available, indirect ELISA. Peripheral blood mononuclear cells (PBMC) were collected from 10 BoHV-4 seropositive cows, and PBMC were examined by a pan-herpesvirus nested PCR to detect herpesvirus. PCR products were sequenced directly and a proportion of the PCR products were cloned and sequenced to identify the virus present. RESULTS: Antibodies to BoHV-4 were detected in 23/92 (25%) serum samples. The pan-herpesvirus PCR was positive in 8/10 PBMC samples. Cloning and sequencing identified that all of the eight PCR-positive PBMC contained bovine lymphotropic herpesvirus (BLHV); no BoHV-4 DNA was detected. CONCLUSIONS: This study reports the finding of the presence of apparent antibodies to BoHV-4, and BLHV DNA in New Zealand dairy cows affected by metritis. CLINICAL RELEVANCE: Bovine herpesvirus type 4 and BLHV are reported to have the potential to cause reproduction failure in cows. This is the first report of apparent BoHV-4 antibodies, and BLHV in New Zealand. The importance and epidemiology of these viruses in cattle in New Zealand requires further investigation.

Seminal transmission of lumpy skin disease virus in heifers.

It is known that lumpy skin disease virus (LSDV) can be shed in bull semen following infection and also that artificial insemination (AI) poses a biosecurity risk. However, it is not known whether the use of LSDV infected semen in AI poses a biosecurity risk. The aim of this study was to investigate whether LSDV, transmitted through semen, can infect cows and their embryos. Two controlled trials were performed simultaneously. Eleven young beef heifers, naïve to LSDV, were synchronized using an OvSynch protocol and inseminated on Day 0 with fresh semen spiked with a field strain of LSDV on day 0. Six of the heifers were superovulated on Day 1 using pregnant mare serum gonadotropin, and embryos were flushed from these heifers on Day 6. Blood and serum samples were collected from Day 4 until Day 27 to determine the presence of LSDV by PCR and virus isolation, and the presence of antibodies against LSDV by SNT. The first clinical signs of LSD were noticed on Day 10, followed by severe generalized LSD in three heifers and mild LSD in two more heifers. Two heifers were humanely euthanized due to severe unresponsive stranguria. LSDV was detected by PCR, virus isolation or electron microscopy in blood, embryos and organs of experimentally infected animals; and eight heifers had seroconverted by Day 27. Two control animals were not affected. This is the first report of experimental seminal transmission of LSDV in cattle.

[Clinical and immunological efficiency of sodium nucleospermate in treating chronic endometritis and infertility complicated by HPV infection].

Clinical efficacy of sodium nucleospermate (SNS) has shown in the treatment of 26 female patients with chronic endometritis, unsuccessful attempts at in vitro fertilization, and persistent viral infection. Cells from endometrium were processed by liquid cytology and studied by immunocytochemistry techniques. It has been clearly established that, after SNS treatment, the frequency of CD20- and CD56-positive cells was significantly decreased (p < 0.05) and the frequency of TLR4 and TLR9 expressing cells in endometrium has been significantly improved (p < 0.05). In addition, the human papilloma virus (HPV) load was reduced as manifested by the real-time PCR test. The obtained results show good prospects for successful use SNS as a means of pathogenetic therapy in patients with this diagnosis.

Postpartum herpes simplex virus endometritis and disseminated infection in both mother and neonate.

BACKGROUND: Herpes simplex virus (HSV) is an unusual cause of postpartum endometritis. We describe a rare case of primary disseminated maternal HSV in the postpartum period associated with endometritis. CASE: A previously healthy patient developed fundal tenderness and postpartum fevers after an uncomplicated vaginal delivery. Despite traditional broad-spectrum antimicrobial therapy, she had persistent fevers and systemic symptoms. Concurrently, her neonate developed fevers and a nonvesicular rash, with viral cultures ultimately returning positive for HSV. The patient developed active pharyngeal and genital herpetic lesions and was diagnosed with HSV endometritis and disseminated HSV. Symptoms and fevers in both the mother and neonate responded to antiviral therapy. CONCLUSION: Herpes simplex virus endometritis should be included in the differential diagnosis for postpartum fevers and fundal tenderness that are unresponsive to broad-spectrum antimicrobial treatment.

Endometrial histopathology in patients with laparoscopic proven salpingitis and HIV-1 infection.

STUDY OBJECTIVE: To identify sensitive and specific histological criteria for endometritis in women with laparoscopically-confirmed acute salpingitis. METHODS: Women, age 18-40 years of age presenting with complaints of lower abdominal pain ≤2 weeks and no antibiotics use in past two weeks, were enrolled. They underwent clinical examination, screening for HIV; other sexually transmitted infections plus endometrial biopsy sampling for histopathology. Diagnostic laparoscopy confirmed the diagnosis of acute salpingitis. Controls were women undergoing tubal ligation and HIV-1 infected women asymptomatic for genital tract infection. RESULTS: Of 125 women with laparoscopically-confirmed salpingitis, 38% were HIV-1 seropositive. Nineteen HIV-1 negative controls were recruited. For the diagnosis of endometritis, ≥1 plasma cells (PC) and ≥3 polymorphonuclear lymphocytes (PMN) per HPF in the endometrium had a sensitivity of 74% for HIV-1-seropositive, 63% for HIV-1-seronegative women with a specificity of 75% and positive predictive value of 85% regardless of HIV-1-infection for predicting moderate to severe salpingitis. For HIV-1-seronegative women with mild salpingitis, ≥1 PC and ≥3 PMN had a sensitivity of 16% and a PPV of 57%. CONCLUSION: Endometrial histology, did not perform well as a surrogate marker for moderate to severe salpingitis, and failed as a surrogate marker for mild salpingitis.

Postpartum endometritis caused by herpes and cytomegaloviruses.

BACKGROUND: Postpartum endometritis is usually a polymicrobial infection caused by organisms that are part of the normal vaginal flora. A pathologically confirmed case of postpartum endometritis secondary to herpes and cytomegalovirus in a human immunodeficiency virus (HIV)-positive patient is reported. CASE: A 29-year-old, HIV-positive woman presented 6 days postpartum with abdominal pain and foul-smelling vaginal discharge. Pelvic ultrasonography revealed retained products of conception. Dilation and evacuation was performed, and antibiotics were started. Despite adequate antibiotics and laparoscopic drainage of a pelvic collection, fevers and pain continued. A total abdominal hysterectomy, salpingectomy, and appendectomy were performed. Pathology reported herpes and cytomegalovirus infection of the uterus. CONCLUSION: Herpes simplex virus (HSV) and cytomegalovirus need to be considered as a potential cause of postpartum endometritis. When antibiotic therapy fails, an antiviral regimen should be considered.

The chemokine IL8 is up-regulated in bovine endometrial stromal cells by the BoHV-4 IE2 gene product, ORF50/Rta: a step ahead toward a mechanism for BoHV-4 induced endometritis.

Postpartum infections of the endometrium and metritis are common causes of delayed conception and infertility in cattle. These infections are characterized by inflammation of the endometrium and secretion of the chemokine interleukin 8 (IL8), which attracts granulocytes to the endometrium. Bovine herpesvirus 4 (BoHV-4) is tropic for the endometrium and the only virus consistently associated with postpartum metritis. The BoHV-4 Immediate Early 2 (IE2) gene is the first viral gene transcribed by host cells after infection, and the IE2 gene product, ORF50/Rta, transactivates host cell genes. The present study tested the hypothesis that ORF50/Rta transactivates the IL8 gene promoter during BoHV-4 infection of bovine endometrial stromal cells (BESCs). Infection of primary BESCs with BoHV-4 stimulated IL8 gene promoter activity and IL8 protein secretion. However, IL8 production was dependent on the transcription of viral genes, because psoralen/ultraviolet cross-linking of the viral DNA abrogated the response to BoHV-4 infection. Furthermore, IL8 promoter serial deletion analysis revealed a specific region responsive to ORF50/Rta. These observations may represent an endometrial defense mechanism against viral infection or a virulence mechanism by which viral replication stimulates chemokine secretion to attract more susceptible host cells to the endometrium.

Isolation and characterization of bovine herpesvirus 4 (BoHV-4) from a cow affected by post partum metritis and cloning of the genome as a bacterial artificial chromosome.

BACKGROUND: Bovine herpesvirus 4 (BoHV-4) is a gammaherpesvirus with a Worldwide distribution in cattle and is often isolated from the uterus of animals with postpartum metritis or pelvic inflammatory disease. Virus strain adaptation to an organ, tissue or cell type is an important issue for the pathogenesis of disease. To explore the mechanistic role of viral strain variation for uterine disease, the present study aimed to develop a tool enabling precise genetic discrimination between strains of BoHV-4 and to easily manipulate the viral genome. METHODS: A strain of BoHV-4 was isolated from the uterus of a persistently infected cow and designated BoHV-4-U. The authenticity of the isolate was confirmed by RFLP-PCR and sequencing using the TK and IE2 loci as genetic marker regions for the BoHV-4 genome. The isolated genome was cloned as a Bacterial Artificial Chromosome (BAC) and manipulated through recombineering technology RESULTS: The BoHV-4-U genome was successfully cloned as a BAC, and the stability of the pBAC-BoHV-4-U clone was confirmed over twenty passages, with viral growth similar to the wild type virus. The feasibility of using BoHV-4-U for mutagenesis was demonstrated using the BAC recombineering system. CONCLUSION: The analysis of genome strain variation is a key method for investigating genes associated with disease. A resource for dissection of the interactions between BoHV-4 and host endometrial cells was generated by cloning the genome of BoHV-4 as a BAC.

Bacterial infection of endometrial stromal cells influences bovine herpesvirus 4 immediate early gene activation: a new insight into bacterial and viral interaction for uterine disease.

Experimental infection with the gamma-herpesvirus bovine herpesvirus 4 (BoHV-4) rarely establishes disease, yet BoHV-4 is commonly associated with uterine disease in cattle. Uterine disease involves co-infection with bacteria such as Escherichia coli, which stimulate the production of prostaglandin E(2) (PGE(2)) by endometrial cells. BoHV-4 replication depends on immediate early 2 (IE2) gene transactivation and, in the present study, PGE(2), E. coli or its lipopolysaccharide upregulated the IE2 gene promoter in uterine cells. Bacterial co-infection is important for BoHV-4 uterine disease.

An investigation of the aetiological role of bovine herpesvirus 4 in bovine endometritis.

Uteri from 31 infertile cattle were examined for the presence of bovine herpesvirus 4 (BoHV-4) by nested polymerase chain reaction (PCR). Samples were also tested for bacteria, including chlamydiae and Mycoplasma bovis. BoHV-4 was detected by PCR in 27/31 (87.1%) samples, but the presence and amount of viral DNA was not correlated with histological and bacteriological findings. Arcanobacterium pyogenes, Histophilus somni and Pasteurella multocida were isolated from five cows with endometritis. Chlamydiae were detected in four cases (12.9%), but only two of these had endometritis. The study does not support a role for BoHV-4 as primary agent in bovine endometritis.

Bovine lymphotropic herpesvirus and non-responsive post-partum metritis in dairy herds in the UK.

Bovine lymphotropic herpesvirus (BLHV) was detected for the first time in the UK in December 2005 in a dairy herd suffering from chronic, non-responsive post-partum metritis (NPPM). A small-scale investigation was undertaken in order to determine whether this was an isolated case. Samples of vaginal exudates or vaginal swabs were collected from cows in 13 UK dairy herds with a history of post-partum metritis that had not responded to standard treatment regimes for this condition. Cows in 9/13 herds and 1/13 herds were positive for BLHV and bovine herpesvirus-4, respectively, by pan-herpesvirus polymerase chain reaction. No consistent pattern of infectious agents or nutritional/metabolic factors commonly associated with post-partum metritis was observed at the times of sampling. The detection of BLHV in association with NPPM indicates that further work is warranted to determine the impact this virus has on cattle health.

Bovine herpesvirus 4 is tropic for bovine endometrial cells and modulates endocrine function.

Bovine postpartum uterine disease, metritis, affects about 40% of animals and is widely considered to have a bacterial aetiology. Although the gamma-herpesvirus bovine herpesvirus 4 (BoHV-4) has been isolated from several outbreaks of metritis or abortion, the role of viruses in endometrial pathology and the mechanisms of viral infection of uterine cells are often ignored. The objectives of the present study were to explore the interaction, tropism and outcomes of BoHV-4 challenge of endometrial stromal and epithelial cells. Endometrial stromal and epithelial cells were purified and infected with a recombinant BoHV-4 carrying an enhanced green fluorescent protein (EGFP) expression cassette to monitor the establishment of infection. BoHV-4 efficiently infected both stromal and epithelial cells, causing a strong non-apoptotic cytopathic effect, associated with robust viral replication. The crucial step for the BoHV-4 endometriotropism appeared to be after viral entry as there was enhanced transactivation of the BoHV-4 immediate early 2 gene promoter following transient transfection into the endometrial cells. Infection with BoHV-4 increased cyclooxygenase 2 protein expression and prostaglandin estradiol secretion in endometrial stromal cells, but not epithelial cells. Bovine macrophages are persistently infected with BoHV-4, and co-culture with endometrial stromal cells reactivated BoHV-4 replication in the persistently infected macrophages, suggesting a symbiotic relationship between the cells and virus. In conclusion, the present study provides evidence of cellular and molecular mechanisms, supporting the concept that BoHV-4 is a pathogen associated with uterine disease.

Infectious correlates of HIV-1 shedding in the female upper and lower genital tracts.

OBJECTIVES: To determine the effects of vaginal, cervical, and endometrial infections on shedding of HIV-1 RNA in the female genital tract. DESIGN: Cross-sectional. METHODS: Antiretroviral-naive women from Nairobi, Kenya with CD4 cell counts >or= 350 cells/mul had plasma and endocervical wick samples collected for HIV quantification by real-time RNA reverse transcriptase-polymerase chain reaction. Vaginal and cervical Gram stains and endometrial biopsies were obtained. Vaginal Gram stain was used to diagnose bacterial vaginosis and to quantify Lactobacillus levels. RESULTS: Twenty-six of 50 (52%) women had detectable endocervical HIV-1 RNA with a median endocervical viral load of 1760 copies/ml (range: undetectable to 1 1,030,000 copies/ml). Women with decreased Lactobacillus had 15.8-fold [95% confidence interval (CI), 2.0-123] greater endocervical HIV-1 RNA than women with normal Lactobacillus levels. Women with plasma cell (PC) endometritis [>or= 1 PC/high-power field (hpf)] had a 15.8-fold (95% CI, 2.0-120) higher endocervical HIV RNA level than women without PC endometritis. Both these associations remained after controlling for plasma viral load. Cervicitis (>or= 30 polymorphonuclear leukocytes/hpf), however, was not associated with endocervical HIV-1 RNA shedding (P = 0.81). CONCLUSIONS: In HIV-1-infected, antiretroviral-naive women without symptoms of pelvic inflammatory disease infection, abnormal vaginal flora and inflammatory cells in the endometrium affected HIV-1 shedding from the lower genital tract. These data suggest that both the upper and lower genital tracts contribute to female HIV-1 genital shedding.

First Serbian isolates of bovine herpesvirus 4 (BoHV-4) from a herd with a history of postpartum metritis.

Two farms in the Belgrade area have experienced serious problems with postpartal metritis. Serological examination of BoHV-4 infection was done using ELISA test and vaginal swabs were used for virus isolation. Average seroprevalence of BoHV-4 in these farms was 84.37%. BoHV-4 isolation was successful from three vaginal swabs on the MDBK cell line. Rising values of BoHV-4 antibodies were recorded in nine of ten cows with clinical signs of postpartal metritis. PCR and restriction analysis were used for better characterisation and isolate classification. Two isolates showed similarity with MOVAR 33/63 virus type, but one differed in polyrepetitive and other parts of DNA. This was the first isolation and characterisation of BoHV4 from Serbian herds.

Complications associated with caesarean delivery in a setting with high HIV prevalence rates.

OBJECTIVE: This study was designed to determine the prevalence of complications associated with abdominal delivery in a setting of high caesarean section (C/S) and HIV rates. METHOD: A detailed review of the records of 737 C/S performed over a three-month period was conducted in a tertiary teaching hospital in Durban, South Africa. RESULTS: The overall complication rate was 14.2%. Major complications included endometritis, wound sepsis, post-partum haemorrhage and bladder injury. HIV infection may have a negative impact on morbidity rates. Disimpacting the fetal head vaginally had a significant association with endometritis (p=0.021). The use of a corrugated drain did not prevent wound sepsis (p<0.001). CONCLUSION: Complications associated with C/S are common is a setting of high C/S rates and HIV infection.

Bovine herpesvirus 4-associated postpartum metritis in a Spanish dairy herd.

In more than 10 Spanish dairy cows, a bovine herpesvirus 4 (BHV4) associated postpartum metritis was confirmed by virus isolation, BHV4-glycoprotein B (gB) PCR and/or serology. In this study, 12 cows with, and, at the time of sampling, 3 cows without clinical signs of acute postpartum metritis from one large dairy herd in Spain were examined for bacterial and viral infections. Blood, placenta/caruncles and uterine contents were collected between day 1 and day 20 post-calving, and examined for the presence of bacteria and for viruses by virus isolation, BHV4 DNA by BHV4-gB PCR and/or BHV4 antibody titres. Bovine herpesvirus 4 was detected in 83% of the cases with clinical signs of acute postpartum metritis by virus isolation and/or BHV4-gB PCR. An increase of BHV4 antibodies was detected in all examined postpartum metritis cows and in the 3 cows without clinical metritis. Two of these 3 cows developed severe metritis a few dayss after collecting the first blood sample. A concurrent infections of BHV4 and bacteria, mainly Arcanobacterium pyogenes and Streptococcus sp., were detected in 73% of the examined uterine contents collected from postpartum metritis affected cows. This case-report study showed a clear association between BHV4 infections and acute postpartum metritis in dairy cows. In addition, the BHV4-associated postpartum metritis appeared to be an emerging syndrome in this Spanish herd.