Association of Rift Valley fever virus infection with miscarriage in Sudanese women: a cross-sectional study.
Rift Valley fever virus is an emerging mosquito-borne virus that causes infections in animals and human beings in Africa and the Arabian Peninsula. Outbreaks of Rift Valley fever lead to mass abortions in livestock, but such abortions have not been identified in human beings. Our aim was to investigate the cause of miscarriages in febrile pregnant women in an area endemic for Rift Valley fever.



Pregnant women with fever of unknown origin who attended the governmental hospital of Port Sudan, Sudan, between June 30, 2011, and Nov 17, 2012, were sampled at admission and included in this cross-sectional study. Medical records were retrieved and haematological tests were done on patient samples. Presence of viral RNA as well as antibodies against a variety of viruses were analysed. Any association of viral infections, symptoms, and laboratory parameters to pregnancy outcome was investigated using Pearson's χ2test.



Of 130 pregnant women with febrile disease, 28 were infected with Rift Valley fever virus and 31 with chikungunya virus, with typical clinical and laboratory findings for the infection in question. 15 (54%) of 28 women with an acute Rift Valley fever virus infection had miscarriages compared with 12 (12%) of 102 women negative for Rift Valley fever virus (p<0·0001). In a multiple logistic regression analysis, adjusting for age, haemorrhagic disease, and chikungunya virus infection, an acute Rift Valley fever virus infection was an independent predictor of having a miscarriage (odds ratio 7·4, 95% CI 2·7-20·1; p<0·0001).



This study is the first to show an association between infection with Rift Valley fever virus and miscarriage in pregnant women. Further studies are warranted to investigate the possible mechanisms. Our findings have implications for implementation of preventive measures, and evidence-based information to the public in endemic countries should be strongly recommended during Rift Valley fever outbreaks.



Schlumberger Faculty for the Future, CRDF Global (31141), the Swedish International Development Cooperation Agency, the County Council of Västerbotten, and the Faculty of Medicine, Umeå University.
Department of Clinical Microbiology, Virology, Umeå University, Umeå, Sweden.
Maria
M
Baudin
Department of Obstetrics and Gynaecology, Red Sea University, Port Sudan, Sudan.
Ammar M
AM
Jumaa
Department of Parasitology and Medical Entomology, Port Sudan Ahlia College, Port Sudan, Sudan.
Huda J E
HJE
Jomma
Faculty of Medical Laboratory Sciences, Karary University, Khartoum, Sudan.
Mubarak S
MS
Karsany
Swedish Defence Research Agency, CBRN Defence and Security, Umeå, Sweden.
Göran
G
Bucht
Swedish Defence Research Agency, CBRN Defence and Security, Umeå, Sweden.
Jonas
J
Näslund
Department of Clinical Microbiology, Infectious Diseases, Umeå University, Umeå, Sweden.
Clas
C
Ahlm
Department of Clinical Microbiology, Virology, Umeå University, Umeå, Sweden. Electronic address: magnus.evander@umu.se.
Magnus
M
Evander
Department of Clinical Microbiology, Virology, Umeå University, Umeå, Sweden.
Nahla
N
Mohamed
D000022:Abortion, Spontaneous / Q000209:etiology* / Q000821:virology; D000818:Animals; D003430:Cross-Sectional Studies; D004196:Disease Outbreaks; D005260:Female; D005334:Fever / Q000209:etiology / Q000821:virology; D006801:Humans; D016015:Logistic Models; D000072138:Mosquito Vectors; D016017:Odds Ratio; D011247:Pregnancy; D011256:Pregnancy Outcome; D012295:Rift Valley Fever / Q000150:complications* / Q000635:transmission / Q000821:virology; D012296:Rift Valley fever virus / Q000472:pathogenicity; D013397:Sudan