Dear Editor,
Oropouche virus (OROV) was first identified in Brazil during the 1960s and has since emerged as a recurrent public health concern in the region [1]. Historically, the virus was primarily transmitted by the midge Culicoides paraenesis, with outbreaks largely confined to the Amazon basin. However, the recent 2022–2024 outbreak in Brazil represents a significant shift, as the virus has established widespread community transmission across all regions of the country. Furthermore, cases have been reported in several non-endemic areas, including Cuba, Italy, Spain, the USA, and Germany, highlighting the increasing potential for international spread [2]. Despite these developments, OROV remains frequently underreported due to its clinical overlap with other arboviruses such as dengue, chikungunya, and Zika, which complicates both diagnosis and surveillance efforts [3].
One of the vulnerable groups deeply concerned by OROV infection is pregnant women, due to its potential for vertical transmission and associated maternal and fetal complications [4]. This emerging arbovirus, prevalent in Latin America, has been associated with severe outcomes such as stillbirth and congenital anomalies, including microcephaly. Evidence suggests that OROV can cross the placental barrier, leading to direct fetal infection and adverse outcomes [4,5]. Maternal complications often present as febrile illness, characterized by fever, myalgia, and headache, with documented cases of miscarriage indicating possible links to early pregnancy loss. Fetal complications include stillbirth and microcephaly, with OROV-specific antibodies detected in cerebrospinal fluid and viral presence confirmed in fetal tissues [4]. These findings underscore the critical need for heightened awareness and preventive measures for pregnant women in affected regions.
OROV infection during pregnancy presents significant challenges, as there are currently no specific antiviral treatments available to prevent transmission to the fetus or mitigate the infection's effects. Symptomatic management, including rest, adequate hydration, and the use of over-the-counter analgesics such as acetaminophen for fever and pain, remains the primary approach. In more severe cases, hospitalization or additional medical care may be necessary. It is important to avoid aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) due to the increased risk of bleeding. Pregnant women affected by OROV should consult their healthcare provider to establish a comprehensive monitoring plan for both maternal health and fetal assessment at birth.
While the direct mechanisms of OROV impact on pregnancy remain under investigation, its ability to infect the placenta and fetus highlights a significant threat to fetal development. However, when traveling to areas affected by OROV, pregnant women should take essential preventive measures to protect themselves from insect bites. The use of Environmental Protection Agency (EPA)-registered insect repellents is recommended, as these are proven safe and effective during pregnancy and breastfeeding. Wearing long-sleeved shirts and long pants offers additional protection. Staying in accommodations with air conditioning or properly screened windows and doors can help minimize exposure to biting midges and mosquitoes. It is also important to ensure that window and door screens have a mesh size of 20 × 20, as many standard screens may not effectively block these insects from entering the home. By taking these precautions, pregnant women can significantly reduce their risk of OROV infection and protect both their health and the health of their unborn child. Moreover, further research is essential to fully understand the virus's effects and to develop effective public health strategies to protect pregnant women in affected regions.
CRediT authorship contribution statement
Beema T Yoosuf: Conceptualization, Data curation, Investigation, Writing – original draft. Rachana Mehta: Supervision, Validation, Writing – review & editing. Sanjit Sah: Conceptualization, Supervision, Validation, Writing – review & editing.
Declaration of competing interest
The authors declare no competing interests.
Handling Editor: Patricia Schlagenhauf
References
- 1.Tilston-Lunel N.L. Oropouche virus: an emerging orthobunyavirus. J Gen Virol. 2024;105(9) doi: 10.1099/jgv.0.002027. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Azevedo E.A.N., Silva A.F.D., Silva V.G.D., Machado L.C., de Lima G.B., Ishigami B.I.M., et al. Genomic and phenotypic characterization of the Oropouche virus strain implicated in the 2022-24 large-scale outbreak in Brazil. J Med Virol. 2024;96(10) doi: 10.1002/jmv.70012. [DOI] [PubMed] [Google Scholar]
- 3.Fonseca L., Carvalho R.H., Bandeira A.C., Sardi S.I., Campos G.S. Oropouche virus detection in febrile patients' saliva and urine samples in Salvador, Bahia, Brazil. Jpn J Infect Dis. 2020;73(2):164–165. doi: 10.7883/yoken.JJID.2019.296. [DOI] [PubMed] [Google Scholar]
- 4.Schwartz D.A., Dashraath P., Baud D. Oropouche virus (OROV) in pregnancy: an emerging cause of placental and fetal infection associated with stillbirth and microcephaly following vertical transmission. Viruses. 2024;16(9) doi: 10.3390/v16091435. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Garcia Filho C., Lima Neto A.S., Maia A., da Silva L.O.R., Cavalcante R.D.C., Monteiro H.D.S., et al. A case of vertical transmission of Oropouche virus in Brazil. N Engl J Med. 2024;391(21):2055–2057. doi: 10.1056/NEJMc2412812. [DOI] [PubMed] [Google Scholar]