Rift Valley fever virus detection in susceptible hosts with special emphasis in insects.

Rift Valley fever phlebovirus (RVFV, Phenuiviridae) is an emerging arbovirus that can cause potentially fatal disease in many host species including ruminants and humans. Thus, tools to detect this pathogen within tissue samples from routine diagnostic investigations or for research purposes are of major interest. This study compares the immunohistological usefulness of several mono- and polyclonal antibodies against RVFV epitopes in tissue samples derived from natural hosts of epidemiologic importance (sheep), potentially virus transmitting insect species (Culex quinquefasciatus, Aedes aegypti) as well as scientific infection models (mouse, Drosophila melanogaster, C6/36 cell pellet). While the nucleoprotein was the epitope most prominently detected in mammal and mosquito tissue samples, fruit fly tissues showed expression of glycoproteins only. Antibodies against non-structural proteins exhibited single cell reactions in salivary glands of mosquitoes and the C6/36 cell pellet. However, as single antibodies exhibited a cross reactivity of varying degree in non-infected specimens, a careful interpretation of positive reactions and consideration of adequate controls remains of critical importance. The results suggest that primary antibodies directed against viral nucleoproteins and glycoproteins can facilitate RVFV detection in mammals and insects, respectively, and therefore will allow RVFV detection for diagnostic and research purposes.

Seroprevalence and Associated Risk Factors of Rift Valley Fever in Domestic Small Ruminants in the North Region of Cameroon.

Rift Valley fever (RVF) is a zoonotic vector borne infectious disease of major medical and veterinary importance particularly in sub-Saharan Africa. However, there is dearth of epidemiological knowledge of the disease in Cameroon. We conducted a cross-sectional study (January 2016-January 2017) to investigate the seroprevalence and potential risk factors of Rift Valley fever virus (RVFV) in sheep and goats in the North region of Cameroon. Stratified sampling approach was used to select herds where sera were collected from 680 randomly selected small ruminants (355 goats and 325 sheep) in eight localities (Kismatari, Lagdo, Pitoa, Garoua, Bocklé, Dembo, Poli and Touboro) within three administrative divisions (Bénoué, Mayo-Rey and Faro) in the North region. Anti-RVFV antibodies were detected using a competitive Enzyme-Linked Immunosorbent Assay (ELISA), while a capture ELISA was used for the detection of specific RVFV-Immunoglobulin M (Ig-M) antibodies. We evaluated the associated potential risk factors of RVF in small ruminants based on observations of animal-related intrinsic and extrinsic factors in combination with serological results. The results revealed that 3.4% (95% confidence interval (CI): 2.2-5.1%) of sampled animals and 24.6% (95% CI: 15.1-37.1%) of 65 sampled herds were seropositive for anti-RVFV antibodies and no difference in seropositivity between sheep and goats at individual animal as well as at herd levels was observed. Localities along hydrographic or large water banks such as Kismatari (OR: 14.333, (95% CI: 1.436-145.088)) and Pitoa (OR = 11.467 (95% CI: 1.249-50.306)) were significantly associated to RVFV antibody seroprevalence in a simple logistic regression. In addition, the multiple regression analysis showed that age and access to water points significantly influenced RVFV antibody seroprevalence in small ruminants. This study revealed that anti-RVFV antibodies are present in sheep and goats in the North region of Cameroon. It highlights the likely endemic circulation of RVFV in the considered localities despite the absence of clinical cases reported in animals or humans. Under these conditions, it is necessary to set up an early warning, surveillance and control strategy based on epizootic risk.

Evidence for enzootic circulation of Rift Valley fever virus among livestock in Cameroon.

Rift Valley fever virus (RVFV) is an arthropod-borne pathogen, causing serious epidemics in Africa and the Arabian Peninsula. In Cameroon serological data indicate the presence of RVFV, but active circulation of RVFV, causing clinical infections has not been proven yet. For this purpose we carried out a serological and molecular study on a total of 1953 randomly selected serum samples of small ruminants and cattle, which were collected in years 2013 and 2014 in Cameroon. In a first step, sera were screened serologically using a variety of assay formats to reveal RVFV specific antibodies. At the second stage, seropositive specimen were assessed for acute RVFV infections via IgM-specific ELISA and quantitative real-time RT-PCR. Our data show a significant difference in the antibody prevalence in cattle (13.5% [95% confidence interval: 11.4-15.7]) and small ruminants (3.4% [95% confidence interval: 2.3-4.7]), with indications for annual fluctuations and significant regional differences of seropositivity. One small ruminant and three bovines were eventually found to be positive in IgM ELISA and indications for viremia were found in one bovine by RVFV genome detection using quantitative real-time RT-PCR. The results of this study therefore corroborate the presence of acute RVFV-infection and its circulation in Cameroon.

Vaccination of alpacas against Rift Valley fever virus: Safety, immunogenicity and pathogenicity of MP-12 vaccine.

Rift Valley fever (RVF) is an emerging zoonosis of major public health concern in Africa and Arabia. Previous outbreaks attributed camelids a significant role in the epidemiology of Rift Valley fever virus (RVFV), making them an important target species for vaccination. Using three alpacas as model-organisms for dromedary camels, the safety, immunogenicity and pathogenicity of the MP-12 vaccine were evaluated in this study. To compare both acute and subacute effects, animals were euthanized at 3 and 31days post infection (dpi). Clinical monitoring, analysis of liver enzymes and hematological parameters demonstrated the tolerability of the vaccine, as no significant adverse effects were observed. Comprehensive analysis of serological parameters illustrated the immunogenicity of the vaccine, eliciting high neutralizing antibody titers and antibodies targeting different viral antigens. RVFV was detected in serum and liver of the alpaca euthanized 3dpi, whereas no virus was detectable at 31dpi. Viral replication was confirmed by detection of various RVFV-antigens in hepatocytes by immunohistochemistry and the presence of mild multifocal necrotizing hepatitis. In conclusion, results indicate that MP-12 is a promising vaccine candidate but still has a residual pathogenicity, which requires further investigation.

Serological and genomic evidence of Rift Valley fever virus during inter-epidemic periods in Mauritania.

Rift Valley fever virus (RVFV) is an emerging pathogen of major concern throughout Africa and the Arabian Peninsula, affecting both livestock and humans. In the past recurrent epidemics were reported in Mauritania and studies focused on the analysis of samples from affected populations during acute outbreaks. To verify characteristics and presence of RVFV during non-epidemic periods we implemented a multi-stage serological and molecular analysis. Serum samples of small ruminants, cattle and camels were obtained from Mauritania during an inter-epidemic period in 2012-2013. This paper presents a comparative analysis of potential variations and shifts of antibody presence and the capability of inter-epidemic infections in Mauritanian livestock. We observed distinct serological differences between tested species (seroprevalence: small ruminants 3·8%, cattle 15·4%, camels 32·0%). In one single bovine from Nouakchott, a recent RVF infection could be identified by the simultaneous detection of IgM antibodies and viral RNA. This study indicates the occurrence of a low-level enzootic RVFV circulation in livestock in Mauritania. Moreover, results indicate that small ruminants can preferably act as sentinels for RVF surveillance.

[Effects of acidosis on the adaptive behavior of full-term newborn infants]. / Der Einfluss der Azidose auf das Adaptationsverhalten reifer Neugeborener.

59 full term, appropriate for gestational age newborn infants (20 delivered by forceps, 39 by cesarean section) with umbilical artery pH below 7.20 are studied in their adaptation period immediately after delivery up to 120 minutes by neonatal monitoring (cardiorespirogram). Control group consists of 50 newborn infants with normal pH (pH greater than or equal to 7.20). There are differences of baseline, of amplitude and frequency of long-term variability and of the initial tachycardytime. The interval to arrive the level of control group depends from the degree of acidosis. Results are demonstrated in 8 diagrams and discussed.

[IgM antibodies against cytomegalovirus in pregnancy and incidence of intrauterine infections in pregnant women with positive IgM antibody reaction (author's transl)]. / IgM-Antikörper gegen Zytomegalievirus in der Schwangerschaft und Häufigkeit intrauteriner Infektionen bei IgM-Antikörpe positiven Schwangeren.

In 47 of 620 pregnant women (7.6%) examined during the first, second and third trimester, it was possible to identify IgM, antibodies against late antigen (LA) of the cytomegalovirus during one or several examinations. 6 of 37 examined children of mothers with positive IgM antibody reaction were found to have intrauterine infection, although there had been no clinical signs of an infection at the time of delivery. All 6 children with intrauterine infection were from 32 mothers (18.8%) with IgM antibodies during the first trimesters. The IgM antibodies of the mothers with children having intrauterine infection did not differ fundamentally from the IgM antibody levels of the mothers with non-infected children with regard to titration value and persistency.

[Catamnestic findings in breech-presentation births]. / Katamnestische Erhebungen bei Beckenendlagengeburten.

Connections exist between the delivery technique for breech presentation cases and the intellectual development of infants. Extracted infants show lower development quotients (EQ) than others delivered with a modified Bracht. Diagnostic symptoms of early brain damage are found in either group. No symptom combination appears to have a significant effect on the EQ level. A prospective delivery technique should be selected in the case of breech presentation on the basis of specific criteria.

[Cardiotokography, obstetrical decission, and perinatological results]. / Kardiotokographie, geburtsmedizinische Entscheidung und perinatologische Ergebnisse

For clinical use we divide the cardiotocographic parameters in 4 groups with the following percentages for antenatal or intranatal period. Normal criterias (antenatal: 80%; intranatal: 40%) Warn symptoms (antenatal: 5%; intranatal: 10%) Umbilico-placental circulatory disturbances (antenatal: 6%; intranatal: 45%) Signs of hypoxia (antenatal: 9%; intranatal: 5%). Variable decelerations are typically for disturbances in the umbilico-placental circulation. The clinical reasons are as well cord compressions as uterine hyperactivity or supine hypotensive syndrom. A prospective management of labor is possible only by means of CTG. The fetal death during labor is avoidable. The number of fetal micro-blood-samplings was reduced (in our hospital 10%) and the feto-maternal relationship was included. The operative frequency is the result of objective obstetrical decisions. We have before and after introduction of fetal monitoring a constant frequency of caesarean sectio of about 3%. A rise in operative frequency simultaneously with the beginning of fetal monitoring is due by a high operative activity in cases of umbilico-placental circulatory disturbances. The rate of neurological findings in newborn infants can be decreased. This result is not valid in preterm or small for date infants.

[Critical notes on delivery and perinatal mortality in single breech presentation deliveries]. / Kritische Anmerkung zur Geburtsleitung und perinatalen Mortalität bei Beckenendlagen-Einlingsgeburten

This report deals with 432 single breech presentation deliveries. Caesarean section frequency was 12,3%. As to the vaginal route of delivery, the simple Bracht manoeuvre had been prefered; in recent times, however, the assisted spontaneous delivery with oxytocin-infusion has been introduced. The corrected perinatal mortality was 4,9%. The rate of prematurely born infants amounted to 14,6%. The corrected perinatal mortality of infants up to 2500 g was 3,3%; of full term infants it was 1,4%. The importance of breech presentation delivery as a high risk delivery is being emphasized. Fetal monitoring and blood gas analysis were required. Indications of caesarean section and suggestions for the management of breech presentations were established. Generally caesarean section of primiparae is not recommended. The diminished rate of prematurely born infants is considered to be of great importance for the decrease of perinatal mortality of breech presentation infants. Intensive pregnancy care, widely used uterotocolysis, and cervix-cerclage in cases of breech presentation are recommended.