Novel replication profiles of Brucella in human trophoblasts give insights into the pathogenesis of infectious abortion

Inflammatory Mechanism of Brucella Infection in Placental Trophoblast Cells

Brucellosis is a severe zoonotic infectious disease caused by the infection of the Brucella, which is widespread and causes considerable economic losses in underdeveloped areas. Brucella is a facultative intracellular bacteria whose main target cells for infection are macrophages, placental trophoblast cells and dendritic cells. The main clinical signs of Brucella infection in livestock are reproductive disorders and abortion. At present, the pathogenesis of placentitis or abortion caused by Brucella in livestock is not fully understood, and further research on the effect of Brucella on placental development is still necessary. This review will mainly introduce the research progress of Brucella infection of placental trophoblast cells as well as the inflammatory response caused by it, explaining the molecular regulation mechanism of Brucella leading to reproductive system disorders and abortion, and also to provide the scientific basis for revealing the pathogenesis and infection mechanism of Brucella.

Consequences of brucellosis infection during pregnancy: A systematic review of the literature

BACKGROUND

The aim was to establish the incidence of adverse outcomes with brucellosis infection during pregnancy.

METHODS

Ovid Medline (1946-), Ovid Embase (1974-), and Web of Science (Clarivate Analytics) (1900-), the World Health Organization website and Google were searched September 27, 2017 for (i) outcomes with brucellosis diagnosed during pregnancy and (ii) studies with retrospective diagnosis of maternal brucellosis following adverse pregnancy outcomes.

RESULTS

Sixty studies met inclusion criteria. In 65 pregnancies from 28 case reports and 9 small case series (<10 women), there were 20 spontaneous abortions (SAs) (31%), 2 intra-uterine fetal deaths (IUFDs) (3%) and 11 cases of congenital brucellosis (17%). In 14 larger case series there were 181 SAs in 679 pregnancies (27%), 19 IUFDs in 458 pregnancies (4%), and 44 preterm infants (12%) plus 6 infants with congenital brucellosis (2%) in 362 pregnancies. SA, IUFD and preterm delivery incidence were increased with meta-analysis of the 5 case series with controls. Nine studies described brucellosis seroprevalence with adverse pregnancy outcomes with no increased seroprevalence in the two studies with controls.

CONCLUSIONS

Brucellosis almost certainly causes SA with increasing evidence that it also leads to IUFD and prematurity. Congenital brucellosis occurs in approximately 2% of infants exposed in-utero.

Prevalence of Brucellosis among Women Presenting with Abortion/Stillbirth in Huye, Rwanda

The incidence of human brucellosis is not documented in Rwanda despite several reports on the disease in cattle. Because brucellosis has been associated with abortion, the aim of this study was to investigate the prevalence of positive serology in women presenting with abortion and/or stillbirth. The study was done in Huye District, in the Southern Province of Rwanda, and the patients were recruited from both the University Teaching Hospital of Butare (CHUB) and Kabutare District Hospital. Serum samples were collected and the Rose Bengal plate test (RBPT) was performed on each sample. A questionnaire was also used to investigate potential contacts with animals and/or consumption of raw milk. A total of 60 women were recruited and 15 (i.e., 25%) were Brucella seropositive. The questionnaire showed that those with seropositivity either were in contact with domestic animals (cattle, goat, or sheep) or were consuming raw cow's milk. Human brucellosis appears to be of public health importance in Rwanda and more attention should be drawn on the disease. The current study provides a basis for larger studies to establish the incidence of human brucellosis in Rwanda. More mechanistic studies will also demonstrate the pathogenicity of Brucella in human placentas.