Rift Valley fever and Crimean–Congo hemorrhagic fever in Mauritania: future recommendations and mitigation strategies – a correspondence

Highlights On 29 August 2022 confirmed cases of River Valley fever and Congo–Crimean hemorrhagic fever (CCHF) were reported in Mauritania, North West Africa. Mauritania is among the most populated African countries with reported early and auspicious rainy seasons in concurrence with reported cases of River Valley fever and CCHF pose health distress to the health care system. Supportive therapy is arguably the primary therapeutic modality. CCHF infections in humans have received treatment with the broad-spectrum antiviral drug ribavirin, but the therapeutic benefits are still elusive. Corticosteroids, particularly immunoglobulins and convalescent serum, are further treatments. Recommendations to mitigate the situation include but are not limited to case reporting and tracing of potential contacts, and protection of individuals at high risk, such as health care workers. Mass education on recommended prevention methods against these deadly diseases and awareness campaigns on early signs and symptoms will together add value to the preparedness part of the response to the outbreak. Viral hemorrhagic fever is a disease that affects both humans and animals and ranges from mild febrile illness to death. It is caused mainly by the Rift Valley fever (RVF) and Congo–Crimean hemorrhagic fever (CCHF) viruses, which are responsible for major outbreaks worldwide1. RVF is a viral disease transmitted to humans and livestock by mosquitoes and blood-feeding flies, while CCHF is transmitted by hard ticks of Hyalomma2. In humans, they cause high fever, neurological symptoms, hepatic pathologies, and hemorrhagic fever, which may progress to death1. In this paper, we address emerging and serious diseases that cause a heavy economic burden and tremendous losses in lives and resources without effective preventive medical measures such as vaccination or drugs that could prevent transmission to other countries. On 29 August 2022, the Mauritanian Ministry of Health stated that a recent case of CCHF had been detected in a 28-year-old pregnant lady from Diabbe and a case of RVF has been detected in a 25-year-old male in the Hodh El Gharbi region3. RVF is caused by RVF virus, of the genus Phlebovirus, and CCHF is caused by CCHF virus (CCHFV), of the genus Orthonairovirus, both belonging to the order Bunyaviridae2. CCHFV transmission to humans occurs through the bite of mainly Hyalomma ticks exposed to infected animals. Remnants of infected animals are an important factor in the accidental infection of humans with the infamous CCHF and RVF due to direct contact with blood, fluids, and infected remnants of animals. The incubation period of RVF disease for symptoms to occur in humans is between 3 and 6 days4. The onset of CCHFV symptoms following contact is usually between 5 and 7 days4. One of the major factors that plays important role in an increased level of transmission is climatic conditions and disasters like floods4. El Mamy et al.5 state that public health authorities and veterinarians implemented the necessary control measures to deal with this epidemic, including limiting animal mobility, reallocating locust control teams for insecticide spraying, and launching awareness campaigns for people at risk. In addition, animal sentinel herds using risk-mapping modeling and communication between the public health and veterinary sectors before rain may be implemented to detect and avoid arboviruses among farmers5. For health care workers, standard barrier precautions, including the use of an alcohol-based hand sanitizer, a level 2 face mask, a disposable gown, and nonsterile gloves, are required for patients in the early stages of the disease6. A splash-resistant face mask, single-use scrub suits, a full-length waterproof gown or coverall, two pairs of nonsterile nitrile gloves, and eyeglasses with side shields should be added to the protective measures if the patient has body excretions6. Due to cases of transmission in double patient settings, the patient should get care in a separate isolation room, away from the main patient flow, preferably in a negative air pressure isolation room6. Waste needs to be disposed of carefully and burned6. Initiatives such as the ‘One Health’ framework in Mauritania invest in deploying monitoring equipment, analyzing the situation, launching measures, and reviewing the committee’s preparedness to handle any potential developments by using prediction models (Fig. 1)7.Figure 1: Summary of River Valley fever (RVF) and Congo–Crimean hemorrhagic fever (CCHF) in Mauritania: origin, mode of transmission, symptoms, and recommendations.Mitigation strategies and recommendations CCHFV Considering how challenging tick eradication is, effective preventive and therapeutic measures such as vaccinations are urgently needed to avert catastrophic epidemics. CCHFV vaccination programs have so far protected people in preclinical testing, but more knowledge about nonviral recombinant DNA vaccines and attenuated vaccines is critically required for both animals and humans8. Prompt investigations such as PCR in conjunction with serological tests are therefore essential to be established by Public Health organizations for early recognition8. Types are required to enhance the mitigation of epidemics8. RVF The key to reducing infections in humans and mortality is enhancing education and information exposure about the risk factors for RVF infection as well as other prevention strategies, including vector management and safeguarding against infected mosquito bites. Public health campaigns aimed at reducing risk should emphasize: Minimizing the probability of virus transfer from animals to humans because of improper handling and slaughter procedures9. Maintaining personal hygiene by handwashing, wearing protective gear, and other necessary personal protective gear while handling infected animals or butchering animals9. Consuming unpasteurized milk or meat without first properly boiling it to reduce the risk of animal-to-human transmission9. The use of insecticide-treated nets, repellents, and garment coverings to limit the risk of mosquito bites through the execution of vector control actions (such as pesticide spraying and the usage of pesticides on mosquito larvae to diminish their breeding sites)9. Limiting external activities during the mosquitoes’ peak biting seasons To tackle the growing public health hazard, specific antiviral treatments are urgently required10. Supportive therapy is arguably the primary therapeutic modality9. Additionally, over the years, researchers have studied prospective bunyavirus-inhibiting medications, and some of them may be effective against the disease8. CCHFV and RVF viruses are classified as an extremely contagious infection that could result in a global health concern and are recognized as an emergent arboviral zoonotic disease in several nations due to the absence of targeted antiviral medicines, a high fatality rate, unstable vector bionomics, and global warming. Ethical approval Not applicable. Sources of funding Not applicable. Author contribution O.U.: conceptualization, project administration, writing – review and designing. All authors involved in manuscript writing, data collection and assembly, and final approval of the manuscript. Conflicts of interest disclosure Not applicable. Research registration unique identifying number (UIN) None. Guarantor Abubakar Nazir, Oli Health Magazine and Organization, Kigali, Rwanda. ORCID ID: 0000-0002-6650-6982. E-mail: [email protected]