Invasive meningococcal disease – Kingdom of Saudi Arabia

On 13 March 2025, the International Health Regulations (IHR) National Focal Point (NFP) for the Kingdom of Saudi Arabia (KSA) reported 11 cases of invasive meningococcal disease (IMD) to WHO. Additionally, between 11 February and 18 March 2025, the WHO Eastern Mediterranean Regional IHR contact point received reports of six isolated cases of IMD, either through notification or bilateral communication with IHR NFPs. These cases involve individuals who had recently returned from Umrah. Meningococcal disease remains a global public health concern, particularly in the context of mass gathering events such as Hajj and Umrah. The government of Saudi Arabia regularly issues health requirements for Hajj and Umrah, including vaccination policies. As of 10 March 2025, KSA health authorities estimated that only 54% of international Umrah pilgrims had complied with the meningococcal vaccination requirements. The significant number of pilgrims traveling to KSA from countries with varying levels of meningococcal disease incidence presents a risk of international spread during these gatherings. Given the recent notification of these cases linked to Umrah, WHO strongly advises all individuals planning to attend mass gatherings such as Hajj and Umrah to receive vaccination against meningococcal disease at least 10 days prior to travel.

On 13 March 2025, the NFP for KSA reported to WHO 11 confirmed cases of IMD. All cases were associated with individuals who had performed Umrah in KSA between 7 January and 12 March 2025.

Among the 11 confirmed cases, four were reported from three countries in the WHO Eastern Mediterranean Region, while the remaining cases are individuals with travel history from countries in the WHO South-East Asia Region. The median age of cases was 36 years (range 6 – 69 years) and 64% were male. The cases were diagnosed between 7 January and 2 March 2025, and none of the affected individuals had a history of vaccination against meningococcal disease. All cases received treatment in hospitals in KSA, fully recovered and were discharged. Serogrouping tests identified the causative strain as Neisseria meningitidis (N. meningitidis) serogroup W135.

In addition, between 11 February and 18 March 2025, the WHO Eastern Mediterranean Regional IHR contact point received reports—either through notifications or bilateral communication with IHR NFPs —of six isolated cases of IMD among individuals who had recently returned from Umrah. Of these, three cases were reported from the WHO Europe Region and three cases were from the WHO Eastern Mediterranean Region. The median age of cases was 19 years (range 6 – 30 years). Serogroup W135 was confirmed in two of the six cases.

Invasive meningococcal disease is a life-threatening bacterial infection caused by Neisseria meningitidis, associated with severe long-term complications and a high case fatality rate, despite prompt and appropriate treatment.

Meningococcal disease occurs worldwide, and can present as a sporadic, clustered or epidemic-prone infection with varying degrees of endemicity across regions. Outbreaks are more likely to occur in settings that facilitate transmission of infection, such as areas with low vaccination coverage, overcrowded living conditions, limited or disrupted access to healthcare services, and mass gatherings, including religious pilgrimages like Hajj and Umrah.  In the KSA, public health authorities conduct regular risk assessments and continue to identify meningococcal disease as a significant public health threat during mass gatherings. Thus, the requirement of quadrivalent meningococcal vaccination (MenACWY), which protects against serogroups A, C, W, and Y, prior to traveling to KSA for Hajj and Umrah has been maintained in the previous years.  However, vaccination compliance for Umrah was declined over the past two years.

The significant number of pilgrims arriving in KSA from countries with diverse meningococcal disease prevalence increases the risk of international spread. In 2024, 12 cases of meningococcal disease associated to Umrah and/or pilgrimage to KSA were reported from the United States of America, the United Kingdom, and France. Of these, nine patients were unvaccinated, and the vaccination status of remaining three was unknown. Antimicrobial susceptibility data was available for 11 of the 12 cases, and ciprofloxacin-resistant strains were identified in three cases. In 2025, to date, 17 cases associated with travel to KSA for religious pilgrimage have already been reported from multiple countries.

Leadership and coordination:

• Disseminating guidelines: The government of Saudi Arabia regularly issues the health requirements for Hajj and Umrah, which are published on the Ministry of Health (MoH) website and disseminated to all countries through diplomatic channels. A key requirement is that all travelers must receive the MenACWY vaccine before departing from their home country for Umrah and Hajj.

Surveillance:

• Screening at Points of Entry: Health authorities at Saudi Arabia’s points of entry conduct screenings during the Hajj and Umrah seasons by visually checking for signs and symptoms of invasive IMD among incoming travelers. They also review travelers’ health documents to ensure compliance with the required health protocols.
• Conducting regular risk assessments: Public health authorities in Saudi Arabia regularly conduct risk assessments. The country has strengthened surveillance for IMD in the Umrah zone, and continuously monitors Neisseria meningitidis carriage in both Makkah and Madinah.
• Electronic surveillance system: Saudi Arabia has established a comprehensive electronic surveillance system to monitor and control IMD across all healthcare facilities. This system mandates the immediate reporting of all suspected and confirmed cases to public health authorities. Standardized case definitions are provided to ensure accurate and timely identification. Laboratory-based diagnostics, including culture, antimicrobial susceptibility testing, and PCR, are prioritized, along with the collection of detailed demographics, clinical, and epidemiological data to support response efforts. Active surveillance is particularly heightened during mass gatherings to quickly detect and respond to potential outbreaks.

Clinical operations:

• Case management: Healthcare facilities in Saudi Arabia are well-prepared to effectively manage cases of meningococcal disease and their close contacts. This is ensured through the provision of appropriate medical care, including timely diagnosis and prompt treatment, based on the appropriate use of antibiotics. Infection prevention and control practices are followed to minimize the risk of nosocomial (hospital-acquired) transmission.
• Post-exposure chemoprophylaxis: Chemoprophylaxis is an essential preventive measure against meningococcal disease. Antimicrobial prophylaxis is administered to close contacts of confirmed cases to prevent secondary transmission. The selection of the drug of choice should be guided by known antimicrobial resistance patterns.

Vaccination:

Targeted vaccination with a conjugate vaccine is used to prevent disease in the community. Most adults in the Umrah region had received at least one dose of the conjugate vaccine, in addition to routine meningococcal immunization for children.

Risk communication and community engagement:

• Awareness campaigns: Saudi Arabia places strong emphasis on public education and community engagement to promote early detection, timely treatment, and prevention of meningococcal disease. Awareness campaigns are regularly conducted to inform the public on the nature of the disease, its symptoms, and the importance of early medical intervention. These campaigns also highlights the critical role of vaccination, both as part of the national immunization programme and as a mandatory requirement for Hajj and Umrah pilgrims.

Meningococcal disease remains a public health challenge, especially for mass gathering events like Hajj and Umrah.

Umrah is a year-round pilgrimage to Mecca in KSA. The risk of meningococcal disease at mass gatherings like Hajj and Umrah is increased due to the high population influx, the person-to-person transmission through respiratory droplets, and the presence of pilgrims from diverse geographical regions and prolonged close contact—resulting from shared accommodations and participation in rituals. In 2024, it was estimated that 24 million pilgrims performed Umrah, with 50% of those being international pilgrims. Mass gatherings such as those occurring during the Umrah pilgrimage can facilitate the transmission of infectious diseases, including IMD.

Since 2001, strict preventative measures, including mandatory quadrivalent (MenACWY) meningococcal vaccination has mitigated the risk of pilgrimage-associated meningococcal outbreaks. While MenACWY vaccination is highly effective in reducing the risk of outbreaks during Hajj and preventing transmission to the home countries of pilgrims, there are challenges in ensuring the vaccination of the pilgrims in their countries of origin since the compliance with the public health advisory is voluntary. As of 10 March, it was estimated by KSA health authorities that only 54% of international Umrah pilgrims have complied with the meningococcal vaccination requirements.  As returning travelers may spread the disease to their local communities, this risk is further heightened when there is lower compliance with meningococcal vaccination among pilgrims.

Preparedness and surveillance efforts must be maintained year-round, with particular emphasis during peak periods like Ramadan and school holidays that often see a sharp increase in pilgrim numbers. In addition, the risk of importation of meningococcal disease is increased during the epidemic season in the countries of the African meningitis belt (i.e. December through June), several of which are home to large Muslim populations. This potentially affects not only the pilgrims but also other travelers (including those traveling for non-religious purposes) and the wider community.

Another risk factor is the emergence of antibiotic resistance for N. meningitidis strains to fluoroquinolones (ciprofloxacin) and potentially third generation cephalosporins, which can complicate post-exposure prophylaxis and treatment options for individuals with IMD. The growing influx of tourists and relatively long incubation period may account for increased risk of international spread.

Meningococcal disease remains a key public health concern at mass gatherings such as Hajj and Umrah. Despite mandatory vaccination policies, declining compliance in recent years has increased transmission risks.

Preventive and control measures should focus on:

• Ensuring high vaccination coverage before travel.
• Enhancing timely detection, investigation and management of cases and their close contacts.
• Enhancing real-time surveillance and monitoring antimicrobial resistance trends.
• Strengthening risk communication and community engagement to improve compliance.

Strengthening vaccination coverage and compliance for Umrah travelers

• WHO strongly advises individuals attending mass gatherings such as Hajj and Umrah to receive vaccination against meningococcal disease at least 10 days prior to travel. This measure is considered the most effective strategy to prevent the disease and potential outbreaks during these events. Specifically, WHO recommends that all pilgrims receive the quadrivalent meningococcal conjugate vaccine, which covers serogroups A, C, W, and Y, prior to traveling.​
• The authorities of KSA require incoming pilgrims to hold proof of vaccination with quadrivalent meningococcal conjugate vaccine ACWY. This, and other health related entry requirements, are available on the official web site of the Ministry of Health of Saudi Arabia and other governmental platforms. States Parties shall make aware immigration authorities and conveyance operators of health-related requirements implemented by the Saudi Arabia, so that the validity of heath documents carried by travelers to Saudi Arabia can be duly checked before departure and prior to arrival in Saudi Arabia.
• Promotion of coordination among ministries of health, civil aviation, immigration authorities, and Hajj/Umrah tour operators to ensure harmonized implementation of vaccination and entry requirements, including pre-departure checks.

Enhancing timely case detection, investigation, and management

• Timely detection and confirmation as well as prompt, appropriate management of cases are critical control measures against meningococcal disease. Suspected cases should undergo laboratory confirmation, which requires the isolation of N. meningitidis from a normally sterile body fluid, including blood, cerebrospinal fluid, or less commonly, pleural, pericardial or synovial fluid. Confirmatory tests include culture with antimicrobial susceptibility testing as well as molecular investigations (e.g. PCR).
• Antibiotic therapy, typically administered for a total duration of 5 to 7 days, is the cornerstone of treatment. Empiric therapy with intravenous ceftriaxone or cefotaxime should be initiated in suspected cases as soon as possible. Once N. meningitidis is isolated, the antibiotic regimen should be reviewed and adjusted according to AST results.
• Individuals with prolonged exposure while in close proximity to an index case and as well as those directly exposed to their oral secretions are at increased risk of infection. Post-exposure antibiotic prophylaxis is therefore recommended for close contacts as a measure to prevent secondary transmission and eradicate asymptomatic nasopharyngeal carriage. Considering the rising concerns related to ciprofloxacin-resistance among  N. meningitidis isolates, the drug of choice for post-exposure prophylaxis should be selected based upon prevalent antimicrobial resistance patterns. Pre-exposure antimicrobial prophylaxis is not recommended.
• Review and update contact tracing guidance for meningococcal infections on aircraft to ensure alignment with best practices. The RAGIDA (Risk Assessment Guidelines for Infectious Diseases Transmitted on Aircraft) framework from ECDC provides valuable guidance and can serve as a reference.
• Expand the digital health passport system to include comprehensive vaccination records, ensuring all required immunization data for pilgrims is current and verifiable.

Strengthening surveillance

• WHO emphasizes the importance of robust surveillance systems for meningococcal disease to effectively control and prevent outbreaks and to continue sharing information between concerned health authorities. Host countries should conduct ongoing surveillance and rely on a risk-based approach focused on the evaluation, mitigation, and communication of risk to ensure timely and appropriate public health responses.
• WHO also highlights the importance of monitoring antibiotic resistance trends by systematically testing N. meningitidis isolates in order to adequately inform post-exposure prophylaxis and treatment strategies. Available information pertaining to serogroups and genomic sequencing should be timely shared with global surveillance platforms in order to track strain variations and identify potential clusters.

Risk communication and community engagement

• Awareness of requirements through policy briefs to Ministers of Health should be undertaken, emphasizing the critical role of vaccination in preventing outbreaks.
• Risk communication should be undertaken to raise community awareness and boost coverage by: Engaging religious leaders (e.g., mosque imams) to advocate for vaccination within Muslim communities, including during the Friday Prayer Khutba. Other RCCE measures could include: disseminate vaccination requirements through Hajj/Umrah tour operators, mosques, embassies, and airports; work with religious leaders (e.g., imams) to promote health messaging, especially during sermons and gatherings such as Friday prayers; ensure vaccination messaging is clearly visible on official websites (e.g., Saudi MoH, embassies) and in travel documents; launching public awareness campaigns to emphasize the importance and effectiveness of vaccination in preventing meningococcal disease, utilizing social media, traditional media, and community outreach initiatives.
• An information note should be provided to close contacts to raise awareness about the signs and symptoms of disease, along with contact details for reaching health authorities.

WHO does not recommend any restriction on travel and/or trade to the Kingdom of Saudi Arabia on the basis of the information available for the current event.

• WHO meningitis health topic 
• WHO meningitis fact sheet
• WHO page on preventing and controlling meningitis outbreaks 
• CDC MMWR Weekly Report 
• Cases of Meningococcal Disease Associated with Travel to Saudi Arabia
• Meningococcal Disease and Immunization Activities in Hajj and Umrah  
• Prevention of Meningococcal Disease during Hajj and Umrah: Past and Current Measures 
• Emergence of Invasive Meningococcal Disease during Hajj – Post-Pandemic Considerations
• CDC Health Alert on Meningococcal Disease Cases Linked to Umrah
• Disease Transmission and Mass Gatherings: A Case Study on Meningococcal Infection during Hajj 
• Vaccine Shortages and Public Health Challenges for Pilgrimage-Related Meningitis Prevention 
• Meningococcal Disease in the Middle East: A Report from the Global Meningococcal Initiative  

Citable reference: World Health Organization (11 April 2025). Disease Outbreak News; Invasive meningococcal disease in Kingdom of Saudi Arabia. Available at: https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON563