Measles is a highly contagious, vaccine-preventable infectious disease caused by measles virus. Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days. Initial symptoms typically include fever, often greater than 40 °C (104 °F), cough, runny nose, and inflamed eyes. Small white spots known as Koplik's spots may form inside the mouth two or three days after the start of symptoms. A red, flat rash which usually starts on the face and then spreads to the rest of the body typically begins three to five days after the start of symptoms. Common complications include diarrhea, middle ear infection (7%), and pneumonia (6%). These occur in part due to measles-induced immunosuppression. Less commonly seizures, blindness, or inflammation of the brain may occur. Other names include morbilli, rubeola, red measles, and English measles. Both rubella, also known as German measles, and roseola are different diseases caused by unrelated viruses.
Measles vaccine protects against becoming infected with measles. Nearly all of those who do not develop immunity after a single dose develop it after a second dose. When rate of vaccination within a population is greater than 92%, outbreaks of measles typically no longer occur; however, they may occur again if the rate of vaccination decrease. The vaccine's effectiveness lasts many years. It is unclear if it becomes less effective over time. The vaccine may also protect against measles if given within a couple of days after exposure to measles.
The 2009–2010 West African meningitis outbreak was an epidemic of bacterial meningitis which occurred in Burkina Faso, Mali, Niger, and Nigeria since January 2009, an annual risk in the African meningitis belt. A total of 13,516 people have been infected with meningitis, and 931 have died. Nigeria has been the most adversely affected, with over half of the total cases and deaths occurring in the nation. The WHO reported on 27 March 2009 that 1,100 had died and there were 25,000 suspected cases. It is the worst outbreak in the region since 1996, and a third of the world's emergency vaccine stockpile for the bacterial form has been consumed. The GAVI Alliance has been trying to secure more vaccines.
The 2012–2013 Swansea measles epidemic began in November 2012 and was declared over on 3 July 2013. There were a total of 1,219 measles notifications in Swansea, Neath Port Talbot, Bridgend, Carmarthenshire, Ceredigion, Pembrokeshire and Powys, with 1,455 measles notifications for the whole of Wales, 664 of which were in Swansea alone. A total of 88 people were hospitalised for measles infection during the epidemic. One death was reported: a 25-year-old man with giant cell pneumonia brought on by measles infection died on 18 April 2013. The cost associated with treating the sick and controlling the outbreak exceeded £470,000 ($701,898).
Ebola, also known as Ebola virus disease (EVD) and Ebola hemorrhagic fever (EHF), is a viral hemorrhagic fever in humans and other primates, caused by ebolaviruses. Symptoms typically start anywhere between two days and three weeks after infection. The first symptoms are usually fever, sore throat, muscle pain, and headaches. These are usually followed by vomiting, diarrhoea, rash and decreased liver and kidney function, at which point some people begin to bleed both internally and externally. It kills between 25% and 90% of those infected – about 50% on average. Death is often due to shock from fluid loss, and typically occurs between six and 16 days after the first symptoms appear. Early treatment of symptoms increases the survival rate considerably compared to late start. An Ebola vaccine was approved by the US FDA in December 2019.
Recombinant vesicular stomatitis virus–Zaire Ebola virus (rVSV-ZEBOV), also known as Ebola Zaire vaccine live and sold under the brand name Ervebo, is an Ebola vaccine for adults that prevents Ebola caused by the Zaire ebolavirus. When used in ring vaccination, rVSV-ZEBOV has shown a high level of protection. Around half the people given the vaccine have mild to moderate adverse effects that include headache, fatigue, and muscle pain.
Measles is extremely contagious, but surviving the infection results in lifelong immunity, so its continued circulation in a community depends on the generation of susceptible hosts by birth of children. In communities which generate insufficient new hosts the disease will die out. This concept was first recognized by Bartlett in 1957, who referred to the minimum number supporting measles as the critical community size (CCS). Analysis of outbreaks in island communities suggested that the CCS for measles is c. 250,000. Due to the development of vaccination against measles, the world has seen a 99% decrease in measles related cases compared cases before the vaccine was developed.
Ring vaccination is a strategy to inhibit the spread of a disease by vaccinating those who are most likely to be infected.
On 20 January 2016, the health minister of Angola reported 23 cases of yellow fever with 7 deaths among Eritrean and Congolese citizens living in Angola in Viana municipality, a suburb of the capital of Luanda. The first cases were reported in Eritrean visitors beginning on 5 December 2015 and confirmed by the Pasteur WHO reference laboratory in Dakar, Senegal in January. The outbreak was classified as an urban cycle of yellow fever transmission, which can spread rapidly. A preliminary finding that the strain of the yellow fever virus was closely related to a strain identified in a 1971 outbreak in Angola was confirmed in August 2016. Moderators from ProMED-mail stressed the importance of initiating a vaccination campaign immediately to prevent further spread. The CDC classified the outbreak as Watch Level 2 on 7 April 2016. The WHO declared it a grade 2 event on its emergency response framework having moderate public health consequences.
The Democratic Republic of the Congo (DRC) was identified by the World Health Organization (WHO) on 11 May 2017 as having one Ebola-related death.
The 2018 Équateur province Ebola outbreak occurred in the north-west of the Democratic Republic of the Congo (DRC) from May to July 2018. It was contained entirely within Équateur province, and was the first time that vaccination with the rVSV-ZEBOV Ebola vaccine had been attempted in the early stages of an Ebola outbreak, with a total of 3,481 people vaccinated. It was the ninth recorded Ebola outbreak in the DRC.
The Kivu Ebola epidemic was an outbreak of Ebola virus disease (EVD) mainly in eastern Democratic Republic of the Congo (DRC), and in other parts of Central Africa, from 2018 to 2020. Between 1 August 2018 and 25 June 2020 it resulted in 3,470 reported cases. The Kivu outbreak also affected Ituri Province, whose first case was confirmed on 13 August 2018. In November 2018, the outbreak became the biggest Ebola outbreak in the DRC's history, and had become the second-largest Ebola outbreak in recorded history worldwide, behind only the 2013–2016 Western Africa epidemic. In June 2019, the virus reached Uganda, having infected a 5-year-old Congolese boy who entered Uganda with his family, but was contained.
The 2019 Philippines measles outbreak began in early 2019. An outbreak of measles was officially declared in February 2019 in select administrative regions in Luzon and Visayas including Metro Manila by the Philippine government. The outbreak is attributed to lower vaccination rates, from a high of 88% 10 to 15 years previous to 74% at the time of the outbreak, allegedly caused by the Dengvaxia controversy.
The 2019 measles outbreaks refer to a substantial global increase in the number of measles cases reported, relative to 2018. As of April 2019, the number of measles cases reported worldwide represented a 300% increase from the number of cases seen in the previous year, constituting over 110,000 measles cases reported in the first three months of 2019. In the first half of 2019, the World Health Organization received reports of 364,808 measles cases from 182 countries, up 182% from the same time period of 2018 when 129,239 confirmed cases were reported by 181 countries.
Measles was declared eliminated from the United States in 2000 by the World Health Organization due to the success of vaccination efforts. However, it continues to be reintroduced by international travelers, and in recent years, anti-vaccination sentiment has allowed for the reemergence of measles outbreaks.
The 2019–2021 polio outbreak in the Philippines was an epidemic. For the previous 19 years, the Philippines was free of any polio-related diseases. On September 14, 2019, the disease began to resurface through a positive test result done to a 3-year-old girl from Mindanao. After the confirmation of a second case from tests done on a 5-year-old boy, the government of the Philippines publicly declared a polio outbreak on September 19, 2019. On June 11, 2021, the WHO announced that the outbreak has ended.
The 2019 Samoa measles outbreak began in September 2019. As of 6 January 2020, there were over 5,700 cases of measles and 83 deaths, out of a Samoan population of 200,874. Over three per cent of the population were infected. The cause of the outbreak was attributed to decreased vaccination rates, from 74% in 2017 to 31–34% in 2018, even though nearby islands had rates near 99%.
The 2019 Tonga measles outbreak began in October 2019 after a squad of Tongan rugby players came back from New Zealand. As of 5 January, 2020, there have been 612 cases of measles.
The COVID-19 pandemic in the Democratic Republic of the Congo was a part of the worldwide pandemic of coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus 2. The virus was confirmed to have reached the Democratic Republic of the Congo on 10 March 2020. The first few confirmed cases were all outside arrivals.
On 7 February 2021, the Congolese health ministry announced that a new case of Ebola near Butembo, North Kivu had been detected the previous day. The case was a 42-year-old woman who had symptoms of Ebola in Biena on 1 February 2021. A few days after, she died in a hospital in Butembo. The WHO said that more than 70 people who had contact with the woman had been tracked.
