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Disease Outbreak News: Measles - Somalia (27 April 2022)

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Outbreak at a glance

Measles is endemic in Somalia with cases reported every year. In 2022, between epidemiological week 1 and 9, a cumulative of 3509 suspected measles cases have been reported from 18 regions in the country. Response activities are ongoing with WHO providing technical support on surveillance, vaccination, laboratory, case management, training of care health workers and risk communication. Given the low levels of vaccination coverage and a high prevalence of both malnutrition and vitamin A deficiency among children aged under 5 years, the overall risk for measles at the national level is assessed as very high. This risk is further aggravated by a complex humanitarian crisis caused by conflict and droughts, and related displacements.

Outbreak overview

Between 2 January and 5 March 2022, a cumulative of 3509 suspected measles cases have been reported from 18 regions in the country, largely from drought-affected districts. Of these 18 regions, six regions including Bay (1194 suspected cases), Mudug (796 suspected cases), Banaadir (559 suspected cases), Bari (277 suspected cases), Lower Shabelle (121 suspected cases) and Gedo (141 suspected cases) reported the highest number of measles cases. Between 2 January to 5 March, a total of 249 samples were collected and tested at four laboratories in the country (in Garowe, Hargeisa, Kismayo, and Mogadishu). Of these samples, 57% (142 samples) tested positive for measles Immunoglobulin M (IgM); 81% were less than five years of age.

Measles is endemic in Somalia and the annual number of cases has varied substantially in recent years. The largest measles outbreak in recent years was recorded in 2017 when 23 039 suspected cases were reported in 118 districts across all six federal states and the Banaadir Regional Administration of Somalia. In the ongoing epidemic in drought affected districts, a total of 2596 suspected measles cases were reported to WHO in 2020, while a total of 7494 suspected measles cases were reported in 2021.

According to the WHO-UNICEF national estimates of immunization coverage, coverage with the first dose of the measles-containing vaccine (MCV1) is suboptimal in Somalia, estimated at around 46% for the last 10 years. The measles-containing vaccine second dose (MCV2) was introduced to the routine immunization program in November 2021 – but it is not yet introduced in Somaliland.

Epidemiology of measles:

Measles is a highly contagious disease caused by a virus in the paramyxovirus family. It is mainly transmitted through direct contact with infected persons, or indirectly via breathing in contaminated air or touching infected surfaces. The virus infects the respiratory tract, then spreads throughout the body.

The first sign of measles is usually a high fever, which begins about 10 to 12 days after exposure to the virus and lasts four to seven days. A runny nose, a cough, red and watery eyes, and small white spots inside the cheeks can develop in the initial stage. After several days, a rash erupts, usually on the face and upper neck. Over about three days, the rash spreads, eventually reaching the hands and feet. The rash lasts for five to six days, and then fades. On average, the rash occurs 14 days after exposure to the virus (within a range of 7 to 18 days).

Most measles-related deaths are caused by complications associated with the disease. Serious complications are more common in children under the age of five or adults over the age of 30. The most serious complications include blindness, encephalitis (an infection that causes brain swelling), severe diarrhoea and related dehydration, ear infections, or severe respiratory infections such as pneumonia. Severe measles is more likely among poorly nourished young children, especially those with insufficient vitamin A, or whose immune systems have been weakened by HIV/AIDS or other diseases.

No specific antiviral treatment exists for measles virus. Severe complications from measles can be reduced through supportive care that ensures good nutrition, adequate fluid intake and treatment of dehydration.

Routine measles vaccination for children, combined with mass immunization campaigns in countries with high case and death rates, are key public health strategies to reduce global measles deaths.

Public health response

The overall risk at the national level is assessed as very high due to:

• Sub-optimal vaccination coverage through routine immunization and lack of recent supplemental immunization activities (SIA). The last SIA was conducted more than two years ago.

• High levels of malnutrition and vitamin A deficiency in the context of food insecurity leading to increased morbidity and mortality. The United Nations Office for the Coordination of Humanitarian Affairs estimates that 4.5 million people in 71 districts in the country face food insecurity.

• Shortage of essential medical supplies for the management of reported cases of measles.

• An overstretched healthcare system with limited capacity to respond to the current outbreak.

• Limited access to primary health care services for the high proportion of people displaced due to drought.

• Delays in detection and response to alerts due to suboptimal integrated disease surveillance system and lack of reporting in the Early Warning Alert and Response Network (EWARN) which will likely lead to pockets of undetected transmission.

• Limited laboratory capacity as only four laboratories in the country are conducting confirmatory measles testing.

The overall risk at the regional level was assessed as moderate due to the unrestricted movement of people between Somalia and neighbouring countries (Ethiopia, Kenya, and Djibouti) where vaccination coverage is also suboptimal.

The overall risk at the global level was assessed as low given the existing response capacity in place.

WHO advice

Vaccination: Enhanced routine measles vaccination for children and conducting outbreak response mass immunization campaigns are key strategies for effective control of the epidemic and reducing mortality.

WHO urges all Member States to:

  • Ensure that routine immunization coverage with MVC1 and MVC2 is at least 95%.

  • Conduct high-quality mass measles immunization campaigns in countries with low vaccine coverage, optimizing opportunities for integration.

  • Ensure high-quality measles case-based surveillance as a critical strategy for outbreak control, early detection and confirmation of measles cases to ensure timely and proper case management to reduce morbidity and mortality and enable implementation of appropriate public health strategies to control further transmission.

  • In countries that are in the elimination phase, provide a rapid response to imported measles cases through the activation of rapid response teams to stop transmission.

  • Administer vitamin A supplementation to all children above six months of age diagnosed with measles to reduce the complications and mortality (two doses of 50 000 IU for children <6 months of age, 100 000 IU for children 6-12 months of age, or 200 000 IU for children 12-59 months of age, immediately upon diagnosis and on the following day).

International travel or trade: WHO does not recommend any restriction on travel and trade based on available information