Measles, a highly contagious and serious disease, has long been a public health challenge. While significant progress had been made in controlling its spread, 2022 marked a concerning resurgence of outbreaks across various global regions. This article explores the nature of measles, the scope of the 2022 outbreaks, their underlying causes, and effective prevention strategies.
Understanding Measles
Measles, also known as rubeola, is caused by the measles virus. It spreads through airborne droplets released when an infected person coughs or sneezes. The virus can remain infectious in the air and on surfaces for up to two hours.
Symptoms include a high fever, cough, runny nose, and red, watery eyes. A characteristic red rash then appears, spreading across the body. Severe complications can arise, particularly in young children, including pneumonia, encephalitis (brain swelling), severe diarrhea, and even death. Before the measles vaccine became available in 1963, major epidemics occurred every two to three years, causing an estimated 2.6 million deaths annually worldwide.
Global Outbreak Snapshot 2022
The year 2022 witnessed a significant escalation in measles cases globally, signaling a concerning setback in public health efforts. The World Health Organization (WHO) and UNICEF reported a 79% increase in measles cases during the first two months of 2022 compared to 2021, with nearly 17,338 cases reported worldwide. This rise indicated a risk for larger outbreaks, potentially affecting millions of children.
Many outbreaks concentrated in regions with fragile health systems. The majority of reported cases in 2022 occurred in Africa and the East Mediterranean region. Countries like Somalia, Yemen, Nigeria, Afghanistan, and Ethiopia experienced some of the largest and most disruptive outbreaks.
Globally, 21 large and disruptive measles outbreaks were identified in the 12 months leading up to April 2022. These outbreaks strained local health systems, which were already managing other health crises. The actual number of cases was likely even higher, as the COVID-19 pandemic disrupted global surveillance systems, potentially leading to underreporting.
Factors Driving the Outbreaks
A primary factor contributing to the 2022 measles outbreaks was a decline in routine childhood immunizations. The COVID-19 pandemic caused widespread disruptions to health services, diverting resources and reducing access to routine vaccination programs. This resulted in millions of children missing their scheduled doses of basic childhood vaccines.
Approximately 23 million children missed routine childhood vaccines in 2020, the highest number since 2009. This created immunity gaps within communities, making them more susceptible to outbreaks. As of April 2022, 57 vaccine-preventable disease campaigns across 43 countries remained postponed due to pandemic-related issues, impacting 203 million people, with 73 million children at risk from missed measles vaccinations alone.
The spread of misinformation and vaccine hesitancy also played a role in these immunity gaps. This reluctance to vaccinate, combined with disruptions, allowed the measles virus to find unprotected individuals and spread more easily. Population movement and international travel further exacerbated the situation, facilitating the rapid spread of the virus to areas with lower vaccination rates.
Preventing Measles Spread
The most effective measure for preventing measles remains the Measles, Mumps, and Rubella (MMR) vaccine. This vaccine is safe and highly effective in protecting individuals from infection. Achieving and maintaining high vaccination rates within a community is essential for establishing herd immunity, making it difficult for the virus to spread.
Currently, global coverage for the first dose of the measles vaccine stands at 83%, with the second dose at 74%, both below the 95% threshold needed for community protection. Public health efforts also involve robust surveillance systems to quickly identify and respond to new cases, preventing wider transmission. Rapid response measures include isolating infected individuals and offering vaccinations to close contacts. Public awareness campaigns are also important for educating communities about the importance and safety of vaccination, encouraging uptake and addressing concerns.