Meningococcal infections among refugees and immigrants: silent threats of past, present and future.

Globally, there is an increasing number of international migrants. The majority are forced displaced refugees and children unaccompanied by a caregiver, and have limited access to essential public health interventions. Routine vaccination might be interrupted or be incomplete due to conflict areas with limited public health services or a long-unplanned journey. Refugees and migrants may bring infectious disease risks to their country of destination and may be exposed to new risk factors during transit or at their destination. There are lessons learned strategies among refugees and asylum seekers in different countries (vaccination campaign during outbreak, maintain vaccination systems for refugees and medical screening and/or vaccination on arrival) against vaccine-preventable diseases - other than meningococcal infections. Since the 1980s, invasive meningococcal disease (IMD) has been reported as a critical healthcare issue in places of humanitarian crisis such as Thailand and African's meningitis belt. Refugees and migrants are at increased risk of IMD compared with the overall population due to sero-epidemiology in their country of origin, specific characteristics of the IMD, and a number of contacts during the journey. Recently, IMD cases due to serogroups X and W have been reported and are an emerging health threat for persons arriving from Africa to refugee camps in Italy. There have been sporadic case reports of IMD due to serogroup B in Turkey; however, there has not yet been increased disease activity in this population and no outbreaks have been observed. Outbreaks of IMD in refugee camps have been and could be successfully controlled through the implementation of timely and high-coverage vaccination campaigns, and individual cases of IMD can be treated with antibiotics. Research is needed to determine the prevalence of meningococcal carriage and serogroup distribution among refugees and migrants to inform vaccine recommendations. There is no official recommendation for meningococcal vaccination of refugees. Further strategies for prevention and treatment of human immunodeficiency virus, tuberculosis and antibiotic resistance among refugees are directly related to potential prevention methods for IMD. Meningococcal vaccines have been administered only to risk groups in most host countries Thus, further strategies for the definition of new/emerging risk factors for IMD would be helpful to guide vaccine implementation for refugees and immigrants.