Measles outbreaks in the 21st century

Outbreaks of the viral disease measles continue to occur in the 21st century. Although an effective measles vaccine exists, a controversy regarding the popular MMR formulation in the late 1990s has led to reduced vaccination coverage in some countries, which has disrupted efforts towards the eradication of measles.

Americas

Canada

The Canadian government defines endemic measles as a situation where a chain of transmission continues uninterrupted for 12 months.^[1] By this standard, Canada has been free of endemic measles since 1998, but sporadic imported outbreaks have continued.^[1]

Southern regions of the province of Quebec witnessed a measles outbreak affecting 94 persons in the Spring and Summer of 2007. The outbreak lasted 25 weeks, included more than one strain of the measles virus and had 12-17 generations of spread.

In 2008, Canada had more than 30 confirmed cases in Ontario in 2008, with more than half reported in Toronto.^[2]

In 2011, Quebec experienced the largest outbreak of measles in the Americas since 2002.^[3] The outbreak began on 8 January with unvaccinated individuals acquiring the disease whilst traveling to France, a country with high measles incidence, and returning home to Quebec.^[4] Public health officials responded to the outbreak by launching a mass vaccination campaign,^[5] and on 22 December, the outbreak ended with a total of 776 cases having occurred. 615 cases (79%) had not been vaccinated, including 29 infants too young to receive the vaccine. 11% of cases required hospitalization, and complications occurred in 64 cases (8%), with pneumonia being the most common complication observed (3% of cases). No deaths were reported.^[3]

A measles outbreak was declared on 8 March 2014 in regions east of Vancouver in the Fraser Valley area where vaccination rates were known to be low in school and religious groups. A total of 228 cases were confirmed. On March 24, Fraser Health Authority said the outbreak have been contained and confined to the original community. ^[6]

United States

Indigenous measles were declared to have been eliminated in North, Central, and South America; the last endemic case in the region was reported on November 12, 2002.^[7] Outbreaks are still occurring, however, following importations of measles viruses from other world regions. In June 2006, an outbreak in Boston resulted after a resident became infected in India,^[8] and in October 2007, a Michigan girl who had been vaccinated contracted the disease overseas.^[9]

In 1991 in the Philadelphia region, thousands of children were sicked with measles. The epicenter of this outbreak was traced to the Faith Tabernacle Congregation, a Faith Healing church that actively discouraged parishioners from vaccinating their children. A Court Order was obtained to forcibly treat and vaccinate children whose parents would not agree to seeking medical care. Nine children eventually died as a result of this outbreak. ^[10]

Between January 1 and April 25, 2008, a total of 64 confirmed measles cases were preliminarily reported in the United States to the Centers for Disease Control and Prevention,^[11][12] the most reported by this date since 2001, and the highest total number in six years.^[13] Of the 64 cases, 54 were associated with importation of measles from other countries into the United States, and 63 of the 64 patients were unvaccinated or had unknown or undocumented vaccination status.^[14] By July 9, 2008, a total of 127 cases were reported in 15 states, making it the largest US outbreak since 1997 (when 138 cases were reported).^[15] Most of the cases were acquired outside of the United States and afflicted individuals who had not been vaccinated.

On May 24, 2011, the Centers for Disease Control and Prevention reported that the United States has had 118 measles cases so far this year. The 118 cases were reported by 23 states and New York City between Jan 1 and May 20. Of the 118 cases, 105 (89%) were associated with cases abroad and 105 (89%) of the 118 patients had not been vaccinated.^[16]

There was an outbreak of measles in San Diego, California in early 2008. The outbreak is traced to an unvaccinated 7-year-old child who went on a family trip to Europe.^[17][18] The CDC refers to this as an "import-associated outbreak".^[17] The final diagnosis included 11 additional cases of measles in unvaccinated children in San Diego.^[17] All of the confirmed patients were not vaccinated because they were younger than 1, the minimum age for measles inoculation, or because their parents declined to have them vaccinated.^[19] The typical vaccine would be the MMR vaccine. The incident drew attention to the controversy over MMR vaccination. This was San Diego County's first measles outbreak since 1991.^[19]

There was an outbreak of measles in Pima County, Arizona in February 2008. There were 13 laboratory confirmed and 4 probable measles cases, though 22 cases were previously reported.^[20] The outbreak started with a visitor from Switzerland and resulted in a public health emergency declaration by Pima County.^[20] The last confirmed Pima County case occurred in 1994, and the last outbreak occurred in 1991.^[21]

At least 20 members of the Eagle Mountain International Church in North Texas were diagnosed with measles after a few members of the congregation traveled abroad on a mission trip and contracted the disease. The church is part of Kenneth Copeland Ministries, which used to advocate abstaining from vaccinations and immunizations for fear they cause autism.^[22] The church has sponsored several vaccination drives.^[23] Senior Pastor Terri Pearsons, who had previously expressed concerns about potential links between the measles vaccine and autism, was encouraging parishioners to get vaccinated. However, she said she still has some concerns about vaccines, particularly for young children with a family history of autism, and where several immunizations are given at the same time. William Schaffner, professor at the Vanderbilt University School of Medicine, described the pastor as "misinformed" and said that young children are among the most vulnerable to measles.^[24]

In February and March, 2014, 20 confirmed cases appeared in New York City. ^[25]

In December 2014, a measles outbreak began at Disneyland in Southern California. At least 133 people have become infected with measles in 8 states, as of February, 2015. Health officials say 39 cases have been traced to direct exposure at the park, while the rest seem to be infection due to secondary exposure or an unknown vector. Among the 110 California patients, 49 (45%) were unvaccinated; five (5%) had 1 dose of measles-containing vaccine, seven (6%) had 2 doses, one (1%) had 3 doses, 47 (43%) had unknown or undocumented vaccination status, and one (1%) had immunoglobulin G seropositivity documented, which indicates prior vaccination or measles infection at an undetermined time. 12 of the unvaccinated patients were infants too young to be vaccinated. ^[26][27] Medical professionals, such as David Gorski, have criticized physicians and pediatricians in the area who do not adhere to the CDC's recommended vaccination schedule or discourage vaccination, among them Bob Sears and Jay Gordon for reducing vaccination rates and thus weakening herd immunity, and creating a situation in which an outbreak was more likely.^[28][29]

Asia

Israel

Approximately 1000 cases of the disease were reported in Israel between August 2007 and May 2008 (in sharp contrast to just some dozen cases the year before). Many children in ultra-Orthodox Jewish communities were affected due to low vaccination coverage.^[30][31]

Japan

In 2007, a large measles outbreak in Japan caused a number of universities and other institutions to close in an attempt to contain the disease.^[32][33]

Philippines

In 2014 the Philippines experienced a large ongoing measles outbreak. According to the World Health Organization there were 57,564 suspected cases of measles, including 21,403 confirmed cases, 110 measles deaths, were reported in the Philippines from January 1st through December 20th, 2014. Most of the cases were among unvaccinated people.^[34]

Europe

In 2008, Europe faced a measles epidemic, including large outbreaks in Austria, Italy, and Switzerland.^[35] In 2010, 30,367 cases were reported from across the 32 European countries reporting to euvac.net (72% of which were reported from Bulgaria, and 17% from France), and 21 measles-related deaths (17 in Bulgaria, 2 in France, and 1 in Romania).^[36] The World Health Organization reported over 26,000 measles cases in 36 European countries from January to October 2011, with 83% occurring in western Europe.^[37] There were nine deaths, of which six were French, and 7,288 hospitalizations.^[37] In February of 2014, 26 cases in Barcelona, Spain.^[38]

Netherlands

In September 2008 an outbreak occurred among anthroposophists' children in the cities of The Hague and Utrecht. Some 90 infections of unvaccinated children were recorded by the Dutch National Institute for Public Health and the Environment (RIVM) by September 29. It was expected the outbreak would spread to the region of the Veluwe, locally known as a bijbelgordel ("Bible Belt") with a large population of unvaccinated children on religious grounds.^[39]

In June 2013, another outbreak occurred in the Bible Belt in The Netherlands. According to newspaper Algemeen Dagblad, there were 161 infections, of which 5 infected victims were hospitalized critically ill. 2 of the victims had meningitis, two others had pneumonia and from one of them, the complications are still unknown.^[40]

United Kingdom

After the MMR vaccine controversy began, the MMR vaccination compliance dropped sharply in the United Kingdom, from 92% in 1996 to 84% in 2002. In some parts of London, it was as low as 61% in 2003, far below the rate needed to avoid an epidemic of measles.^[41] By 2006 coverage for MMR in the UK at 24 months was 85%, lower than the about 94% coverage for other vaccines.^[42]

After vaccination rates dropped, the incidence of two of the three diseases increased greatly in the UK. In 1998 there were 56 confirmed cases of measles in the UK; in 2006 there were 449 in the first five months of the year, with the first death since 1992.^[43] Cases occurred in inadequately vaccinated children.^[43] The age group affected was too old to have received the routine MMR immunizations around the time the paper by Wakefield et al. was published, and too young to have contracted the natural disease as a child, and thus to achieve a herd immunity effect. With the decline in infection that followed the introduction of the MMR vaccine, these individuals had not been exposed to the disease, but still had no immunity, either natural or vaccine induced. Therefore, as immunization rates declined following the controversy and the disease re-emerged, they were susceptible to infection.^[44][45] Measles cases continued in 2006, at incidence rates 13 times greater than 1998 levels.^[46] Two children were severely and permanently injured by measles encephalitis despite undergoing kidney transplantation in London.^[47]

Disease outbreaks also caused casualties in nearby countries. 1,500 cases and three deaths were reported in the Irish outbreak of 2000, which occurred as a direct result of decreased vaccination rates following the MMR scare.^[47]

In 2008, for the first time in 14 years, measles was declared endemic in the UK, meaning that the disease was sustained within the population. This was caused by the preceding decade's low MMR vaccination rates, which created a population of susceptible children who could spread the disease. In May 2008, a British 17-year-old with an underlying immunodeficiency died of measles.^[48]

An outbreak centered on the Swansea area of Wales started in November 2012; as of 22 April there have been 886 cases.^[49]

Bulgaria

Beginning in April 2009 there was a large outbreak of measles in Bulgaria, with 23,791 cases, including 24 deaths, reported up to 28 July 2010.^[50] From Bulgaria, the strain was carried to Germany, Turkey, Greece, Macedonia, and other European countries.^[51]

France

Between January 2008 and April 2011, over 17,000 cases of measles were reported in France, including 2 deaths in 2010. From January to October 2011, there were 14,000 reported cases of measles in France, leading the country to launch an awareness campaign about MMR vaccination.^[37]

Oceania

Australia

Fourteen cases have been reported in multiple Australian and New Zealand cities including Melbourne and Auckland in the period between December 7, 2013 and January 3, 2014. The outbreak is believed to have begun at the 2013 World Supremacy Battlegrounds dance festival held in Sydney, Australia.^[52]

New Zealand

Ten cases were reported in Christchurch in July 2009.^[53]

An outbreak between 25 May 2011 and 24 July 2012 in the Auckland region had 489 confirmed or probable cases of measles, 82 of which required hospitalisation.^[54] The outbreak was started with an unimmunised child becoming infected on a family trip to England, then developing measles back in Auckland.^[54]

In June and July 2014, 124 confirmed cases of measles were reported in Hamilton. Eighty percent of persons infected were aged between 10 and 20, and all but four were not immunised. Most of those infected were linked with Fraser High School in the city's west, resulting in the school cancelling all school trips and cultural and sporting events.^[55][56]

References

See also

• Eradication of infectious diseases
• Herd immunity
• Vaccine controversy
• MMR vaccine controversy
• Vaccination schedule
• Vaccination policy
• Vaccination and religion
• Measles#Recent outbreaks
• Mumps outbreaks in the 2000s
• Category:2000s medical outbreaks