Plague is an infectious disease caused by the bacteriumYersinia pestis. Symptoms include fever, weakness, headache and black lips. Usually, this begins one to seven days after exposure. There are three forms of plague, each affecting a different part of the body and causing associated symptoms. Pneumonic plague infects the lungs, causing shortness of breath, coughing and chest pain; bubonic plague affects the lymph nodes, making them swell; and septicemic plague infects the blood and can cause tissues to turn black and die.
The bubonic and septicemic forms are generally spread by flea bites or handling an infected animal, whereas pneumonic plague is generally spread between people through the air via infectious droplets. Diagnosis is typically made by finding the bacterium in fluid from a lymph node, blood or sputum.
Vaccination
is recommended only for people at high risk of exposure to plague.
Those exposed to a case of pneumonic plague may be treated with
preventive medication. If infected, treatment is with antibiotics and supportive care. Typically antibiotics include a combination of gentamicin and a fluoroquinolone. The risk of death with treatment is about 10% while without it is about 70%.
Globally, about 600 cases are reported a year. In 2017, the countries with the most cases include the Democratic Republic of the Congo, Madagascar and Peru. In the United States, infections occasionally occur in rural areas, where the bacteria are believed to circulate among rodents. It has historically occurred in large outbreaks, with the best known being the Black Death in the 14th century, which resulted in more than 50 million deaths in Europe.
Signs and symptoms
There are several different clinical manifestations of plague. The
most common form is bubonic plague, followed by septicemic and pneumonic
plague. Other clinical manifestations include plague meningitis, plague pharyngitis, and ocular plague. General symptoms of plague include fever, chills, headaches, and nausea. Many people experience swelling in their lymph nodes if they have bubonic plague. For those with pneumonic plague, symptoms may (or may not) include a cough, pain in the chest, and haemoptysis.
Swollen inguinal lymph glands on a person infected with the bubonic plague. The swollen lymph glands are termed buboes from the Greek word for groin, swollen gland: bubo.
When a flea bites a human and contaminates the wound with
regurgitated blood, the plague-causing bacteria are passed into the
tissue. Y. pestis can reproduce inside cells, so even if phagocytosed, they can still survive. Once in the body, the bacteria can enter the lymphatic system, which drains interstitial fluid. Plague bacteria secrete several toxins, one of which is known to cause beta-adrenergic blockade.
Y. pestis spreads through the lymphatic vessels of the infected human until it reaches a lymph node, where it causes acute lymphadenitis. The swollen lymph nodes form the characteristic buboes associated with the disease, and autopsies of these buboes have revealed them to be mostly hemorrhagic or necrotic.
If the lymph node is overwhelmed, the infection can pass into the bloodstream, causing secondary septicemic plague, and if the lungs are seeded, it can cause secondary pneumonic plague.
Lymphatics ultimately drain into the bloodstream, so the plague
bacteria may enter the blood and travel to almost any part of the body.
In septicemic plague, bacterial endotoxins cause disseminated intravascular coagulation
(DIC), causing tiny clots throughout the body and possibly ischemic
necrosis, in which tissues die due to a lack of blood circulation. DIC
results in depletion of the body's clotting resources so that it can no
longer control bleeding. Consequently, there is bleeding into the skin
and other organs, which can cause a red or black patchy rash, and
coughing up and vomiting of blood. There are bumps on the skin that look
somewhat like insect bites; these are usually red, and sometimes white
in the centre. Untreated, the septicemic plague is usually fatal. Early
treatment with antibiotics reduces the mortality rate to between 4 and 15 per cent.
The pneumonic form of plague arises from infection of the lungs. It causes coughing and thereby produces airborne droplets that contain bacterial cells and are likely to infect anyone inhaling them. The incubation period
for pneumonic plague is short, usually two to four days, but sometimes
just a few hours. The initial signs are indistinguishable from several
other respiratory illnesses; they include headache, weakness, and
spitting or vomiting of blood. The course of the disease is rapid;
unless diagnosed and treated soon enough, typically within a few hours,
death may follow in one to six days; in untreated cases, mortality is
nearly 100%.
Cause
The Oriental rat flea (Xenopsylla cheopis) engorged with blood after a blood meal. This species of flea is the primary vector for the transmission of Yersinia pestis, the organism responsible for bubonic plague in most plague epidemics in Asia, Africa, and South America. Both male and female fleas feed on blood and can transmit the infection.A child bitten by a flea infected with the bacterium Yersinia pestis. Y. pestis, a member of the family Yersiniaceae, has caused the bite to become ulcerated.
Transmission of Y. pestis to an uninfected individual is possible by any of the following means:
droplet contact – coughing or sneezing on another person
direct physical contact – touching an infected person, including sexual contact
indirect contact – usually by touching soil contamination or a contaminated surface
airborne transmission – if the microorganism can remain in the air for long periods
fecal-oral transmission – usually from contaminated food or water sources
Yersinia pestis circulates in animal reservoirs, particularly
in rodents, in the natural foci of infection found on all continents
except Australia. The natural foci of plague are situated in a broad
belt in the tropical and sub-tropical latitudes and the warmer parts of
the temperate latitudes around the globe, between the parallels 55° N
and 40° S. Contrary to popular belief, rats did not directly start the spread of the bubonic plague. It is mainly a disease in the fleas (Xenopsylla cheopis)
that infested the rats, making the rats themselves the first victims of
the plague. Rodent-borne infection in a human occurs when a person is
bitten by a flea that has been infected by biting a rodent that itself
has been infected by the bite of a flea carrying the disease. The
bacteria multiply inside the flea, sticking together to form a plug that
blocks its stomach and causes it to starve. The flea then bites a host
and continues to feed, even though it cannot quell its hunger, and
consequently, the flea vomits blood tainted with the bacteria back into
the bite wound. The bubonic plague bacterium then infects a new person
and the flea eventually dies from starvation. Serious outbreaks of
plague are usually started by other disease outbreaks in rodents or a
rise in the rodent population.
A 21st-century study of a 1665 outbreak of plague in the village of Eyam
in England's Derbyshire Dales – which isolated itself during the
outbreak, facilitating modern study – found that three-quarters of cases
are likely to have been due to human-to-human transmission, especially
within families, a much larger proportion than previously thought.
Diagnosis
Symptoms of plague are usually non-specific, necessitating laboratory testing to definitively diagnose the disease. Y. pestis
can be identified through both a microscope and by culturing a sample
and this is used as a reference standard to confirm that a person has a
case of plague. The sample can be obtained from the blood, mucus (sputum), or aspirate extracted from inflamed lymph nodes (buboes). a person is administered antibiotics before a sample is taken or if
there is a delay in transporting the person's sample to a laboratory
and/or a poorly stored sample, there is a possibility for false negative results.
Polymerase chain reaction (PCR) may also be used to diagnose plague, by detecting the presence of bacterial genes such as the pla gene (plasmogen activator) and caf1 gene, (F1 capsule antigen). PCR testing requires a very small sample and is effective for both alive and dead bacteria. For this reason, if a person receives antibiotics before a sample is
collected for laboratory testing, they may have a false negative culture
and a positive PCR result.
Blood tests to detect antibodies against Y. pestis can
also be used to diagnose plague, however, this requires taking blood
samples at different periods to detect differences between the acute and
convalescent phases of F1 antibody titres.
In 2020, a study about rapid diagnostic tests that detect the F1
capsule antigen (F1RDT) by sampling sputum or bubo aspirate was
released. Results show rapid diagnostic F1RDT test can be used for people who
have suspected pneumonic and bubonic plague but cannot be used in
asymptomatic people. F1RDT may be useful in providing a fast result for
prompt treatment and fast public health response as studies suggest that
F1RDT is highly sensitive for both pneumonic and bubonic plague.
However, when using the rapid test, both positive and negative results
need to be confirmed to establish or reject the diagnosis of a confirmed
case of plague and the test result needs to be interpreted within the
epidemiological context as study findings indicate that although 40 out
of 40 people who had the plague in a population of 1000 were correctly
diagnosed, 317 people were diagnosed falsely as positive.
Bacteriologist Waldemar Haffkine developed the first plague vaccine in 1897. He conducted a massive inoculation program in British India, and it is estimated that 26 million doses of Haffkine's anti-plague vaccine were sent out from Bombay between 1897 and 1925, reducing the plague mortality by 50–85%.
Since human plague is rare in most parts of the world as of 2023,
routine vaccination is not needed other than for those at particularly
high risk of exposure, nor for people living in areas with enzootic
plague, meaning it occurs at regular, predictable rates in populations
and specific areas, such as the western United States. It is not even
indicated for most travellers to countries with known recent reported
cases, particularly if their travel is limited to urban areas with
modern hotels. The United States CDC thus only recommends vaccination for (1) all laboratory and field personnel who are working with Y. pestis organisms resistant to antimicrobials: (2) people engaged in aerosol experiments with Y. pestis;
and (3) people engaged in field operations in areas with enzootic
plague where preventing exposure is not possible (such as some disaster
areas). A systematic review by the Cochrane Collaboration found no studies of sufficient quality to make any statement on the efficacy of the vaccine.
Early diagnosis
Diagnosing plague early leads to a decrease in transmission or spread of the disease.
Prophylaxis
Pre-exposure prophylaxis for first responders and health care
providers who will care for patients with pneumonic plague is not
considered necessary as long as standard and droplet precautions can be
maintained. In cases of surgical mask shortages, patient overcrowding, poor
ventilation in hospital wards, or other crises, pre-exposure prophylaxis
might be warranted if sufficient supplies of antimicrobials are
available.
Postexposure prophylaxis should be considered for people who had
close (<6 feet), sustained contact with a patient with pneumonic
plague and were not wearing adequate personal protective equipment. Antimicrobial postexposure prophylaxis also can be considered for
laboratory workers accidentally exposed to infectious materials and
people who had close (<6 feet) or direct contact with infected
animals, such as veterinary staff, pet owners, and hunters.
Specific recommendations on pre- and post-exposure prophylaxis
are available in the clinical guidelines on treatment and prophylaxis of
plague published in 2021.
Treatments
If diagnosed in time, the various forms of plague are usually highly responsive to antibiotic therapy. The antibiotics often used are streptomycin, chloramphenicol and tetracycline. Amongst the newer generation of antibiotics, gentamicin and doxycycline have proven effective in monotherapeutic treatment of plague. Guidelines on treatment and prophylaxis of plague were published by the Centers for Disease Control and Prevention in 2021.
The plague bacterium could develop drug resistance and again become a major health threat. One case of a drug-resistant form of the bacterium was found in Madagascar in 1995. Further outbreaks in Madagascar were reported in November 2014 and October 2017.
Globally about 600 cases are reported a year. In 2017, the countries with the most cases include the Democratic Republic of the Congo, Madagascar and Peru. It has historically occurred in large outbreaks, with the best known being the Black Death in the 14th century which resulted in more than 50 million dead. In recent years, cases have been distributed between small seasonal
outbreaks which occur primarily in Madagascar, and sporadic outbreaks or
isolated cases in endemic areas. In 2022, the possible origin of all modern strains of Yersinia pestis was found in DNA in human remains in three graves located in Kyrgyzstan, dated to 1338 and 1339. The first recorded occurrence of the Black Death occurred shortly thereafter during the siege of Caffa
in Crimea in 1346, and was carried to Europe by boat by people
attempting to escape the disease. The strain was identified as the most
recent common ancestor of both strains found in historic graves and
currently existing strains. Bacteria affecting marmots
in modern-day Kyrgyzstan are the closest genetically (compared to
samples from infected rodents worldwide) to the strain found in the
graves, suggesting this is also the location where plague transferred
from animals to humans.
Biological weapon
The plague has a long history as a biological weapon.
Historical accounts from ancient China and medieval Europe details the
use of infected animal carcasses, such as cows or horses, and human
carcasses, by the Xiongnu/Huns, Mongols, Turks and other groups, to contaminate enemy water supplies. Han dynasty general Huo Qubing is recorded to have died of such contamination while engaging in warfare against the Xiongnu. Plague victims were also reported to have been tossed by catapult into cities under siege.
In 1347, the Genoese possession of Caffa, a great trade emporium on the Crimean peninsula, came under siege by an army of Mongol warriors of the Golden Horde under the command of Jani Beg.
After a protracted siege during which the Mongol army was reportedly
withering from the disease, they decided to use the infected corpses as a
biological weapon. The corpses were catapulted over the city walls,
infecting the inhabitants. This event might have led to the transfer of
the Black Death via their ships into the south of Europe, possibly
explaining its rapid spread.
During World War II, the Imperial Japanese Army developed weaponized plague, based on the breeding and release of large numbers of fleas. During the Japanese occupation of Manchuria, Unit 731 deliberately infected Chinese, Korean and Manchurian civilians and prisoners of war with the plague bacterium. These subjects, termed "maruta" or "logs", were then studied by dissection, others by vivisection while still conscious. Members of the unit such as Shirō Ishii were exonerated from the Tokyo tribunal by Douglas MacArthur but 12 of them were prosecuted in the Khabarovsk War Crime Trials in 1949 during which some admitted having spread bubonic plague within a 36-kilometre (22 mi) radius around the city of Changde.
Ishii innovated bombs containing live mice and fleas, with very
small explosive loads, to deliver the weaponized microbes, overcoming
the problem of the explosive killing the infected animal and insect by
the use of a ceramic, rather than metal, casing for the warhead. While
no records survive of the actual usage of the ceramic shells, prototypes
exist and are believed to have been used in experiments during WWII.
After World War II, both the United States and the Soviet Union
developed means of weaponising pneumonic plague. Experiments included
various delivery methods, vacuum drying, sizing the bacterium,
developing strains resistant to antibiotics, combining the bacterium
with other diseases (such as diphtheria), and genetic engineering. Scientists who worked in USSR bio-weapons programs
have stated that the Soviet effort was formidable and that large stocks
of weaponised plague bacteria were produced. Information on many of the
Soviet and US projects is largely unavailable. Aerosolized pneumonic
plague remains the most significant threat.
The plague can be easily treated with antibiotics. Some
countries, such as the United States, have large supplies on hand if
such an attack should occur, making the threat less severe.
According to a 2012 Pew Research Center survey, Christianity will remain the world's largest religion
throughout the next four decades. However, Christianity may experience
the largest net losses in terms of religious conversion, according to
expectations. Worldwide, religious conversions are projected to have a
"modest impact on changes in the Christian population" between 2010 and
2050 and may negatively affect the growth of the Christian population and its share of the world's population "slightly". However, these forecasts lack reliable data on religious conversion in
China, but according to media reports and expert assessments, it is
possible that the rapid growth of Christianity in China may maintain, or even increase, the current numerical advantage of Christianity as the largest religion in the world. In the United States, there have been some conversions to Christianity among those who grew up non-religious,
but they have not been in numbers that make up for those who were
raised as Christians but became religiously unaffiliated later in their
lives. According to a Pew
study in 2020, among adults aged 18 to 54 in 117 countries, 83% of
those who were raised Christian remain Christian. The remaining 17% now
identify as non-Christian, and the vast majority of former Christians no
longer identify with any religion.
Scholars have proposed that church institutions decline in power
and prominence in most industrialized societies, except in cases in
which religion serves some function in society beyond merely regulating
the relationship between individuals and God. Developing countries in Latin America and Africa are not experiencing a decline, mostly because of religious conversion in those countries where the church offers broad social support services. Together with the decline of Western Christians, increasing numbers of Christians in the Global South will form a "new Christendom" in which the majority of the world's Christian population will be found in the South. According to various scholars and sources, Pentecostalism – a Protestant Christianmovement – is the fastest-growing religion in the world; this growth is primarily due to religious conversion.
The European Values Study found that in most European countries in 2008, the majority of young respondents identified themselves as Christians. Unlike Western Europe, in Central and Eastern European countries, the proportion of Christians has either been stable or it has increased in the post-communist era. A large majority (83%) of those who were raised as Christians in
Western Europe still identify as such. The remainder mostly
self-identify as religiously unaffiliated. Christianity is still the largest religion in Western Europe, where 71% of Western Europeans identified themselves as Christian, according to a 2018 study by the Pew Research Center.
A 2015 analysis of the European Values Study in the Handbook of Children and Youth Studies identified a "dramatic decline" in religious affiliation across Europe from 1981 to 2008; however, according to the same analysis, "the majority of young
respondents in Europe claimed that they belonged to a Christian
denomination".
In 2017, a report which was released by St. Mary's University, London,
concluded that Christianity "as a norm" was gone for at least the
foreseeable future. In at least 12 out of the 29 European countries
which were surveyed by the researchers, based on a sample of 629 people,
the majority of young adults reported that they were not religious. The data was obtained from two questions, one asking, "Do you consider
yourself as belonging to any particular religion or denomination?" to
the full sample and the other one asking "Which one?" to the sample who
replied with "Yes". The Pew Research Center
criticized the methodology of the two-step approach: "Presumably, this
is because some respondents who are relatively low in religious practice
or belief would answer the first question by saying that they have no
religion, while the same respondents would identify as Christian,
Muslim, Jewish, etc., if presented with a list of religions and asked to
choose among them. The impact of these differences in question wording
and format may vary considerably from country to country".
In 2018, the Pope lamented the ongoing trend of repurposing churches: some of them were being used as pizza
joints, skating parks, strip clubs and bars. In Germany, 500 Catholic
churches have closed since 2000. Canada has lost 20% of its churches in
this time frame. This is the result of a lack of clergy who are willing
to staff churches as well as the result of the churches' inability to
meet costs. After a scandal in Naples where a deconsecrated church became the venue for a Halloween party which featured scantily clad witches who were seated on the former altar, Pope Francis,
acknowledging the decline in Church attendance, implored that the
deconsecrated churches be placed in service to fulfill the social needs
of caring for the poor.
In a new study published in 2022, Pew Research Center projects
that if the rate of switching continues to accelerate (primarily to no
religious affiliation), Christians will make up less than half of the
American population by 2070, with estimated ranges for that year falling
between 35% and 46% of the American population (down from 64% in 2022
and down from 91% in 1976). The same study found a retention rate among American Christians closer
to 67%, with one-third of those who were Christian in childhood leaving
the religion by age 30. As of 2024, Christianity's decline in the United States may have leveled off or slowed, according to the Pew Research Center and Gallup. In 2024, about 73% of Americans raised Christian still identify as
Christian, while 27% are no longer Christian. Most former Christians
describe themselves religiously as atheists, agnostics or nothing in particular.
After years of steep decline, Christian affiliation across much of the Western world has leveled off. In the United States,
for example, studies reports that since around 2020 the share of adults
identifying as Christian has steadied at roughly 62 percent. Among
Generation Z, the reversal is even clearer: church membership climbed
from 45 percent to 51 percent between 2023 and 2024, while the
proportion of religiously unaffiliated "nones" slipped from 45 percent
to 41 percent. A similar pattern is evident in Australia, Austria, Canada, France, Ireland, New Zealand, and the United Kingdom, where studies report that church attendance is rising among young
people—particularly young men—and that Christian self-identification has
stabilized.
Reports also note that young men are converting in notable
numbers to what they see as more "masculine expressions" of
Christianity, such as the Eastern and Oriental Orthodox churches, confessional branches of Evangelical Lutheranism and traditionalist branches of Catholicism. While exact figures are difficult to verify, Pew Research Center data
indicate that the Orthodox Christian population is now about 64% male,
up from 46% in 2007, suggesting a marked demographic shift toward men
within these communities. Congregations of Conservative Anabaptist
denominations have experienced continued growth, with Conservative
Anabaptists having "large families and high retention rates".
In Western countries with large enough Christian samples to
analyze, most people who currently identify as Christian were also
raised Christian. However, in other regions, a significant share of
those who call themselves Christian were not brought up in the faith.
Notably, in countries such as Singapore, South Korea, and Sri Lanka, Christian accession rates exceed 10%. In Singapore in particular, nearly half of Christians (47%) say they were raised outside of Christianity.
Europe
Largest (non-)religious group by EU member state according to Eurobarometer survey 2019.
More than 75% Catholic
50–75% Catholic
Relative Catholic majority
50–75% Protestant
More than 75% Orthodox
50–75% non-religious
Relative non-religious majority
30% Catholic, 30% non-religious (Germany)
According to scholars, in 2017, Europe's population was 77.8% Christian (up from 74.9% in 1970).[48] These changes were largely the result of the collapse of Communism and conversions to Christianity in the former Soviet Union and Eastern Bloc countries. According to the 2021 Eurobarometer survey, Christianity was the largest religion in the European Union, accounting for 66.1% of the EU population, down from 72% in 2012.
In 2017, Pew Research Center found that the number of Christians
in Europe is in decline. This is mainly because the number of deaths is
estimated to exceed the number of births among European Christians, in
addition to lower fertility rates and switching to no religious
affiliation.
In 2018, Pew Research Center found a retention rate among Western
European Christians of around 83% (ranging from 57% in the Netherlands
to 91% in Austria). Despite the decline in Christian affiliation in Western Europe, Christianity is still the largest religion in Western Europe, where 71% of Western Europeans identified themselves as Christian, according to a 2018 study by the Pew Research Center. Unlike Western Europe, in Central and Eastern European countries the proportion of Christians has been stable or even increased in the post-communist era.
The decline of Christianity in the Czech Republic recorded throughout the censuses of 1991, 2001 and 2011.
In Western Europe, Christians have relatively low retention rates in
the Netherlands (57%), Norway (62%), Belgium and Sweden (65%); the
majority of those who have left Christianity in these countries now
identify as religiously unaffiliated. Meanwhile, Christians have relatively high retention rates in Austria
(91%), Switzerland and Italy (90%), and Ireland and the United Kingdom
(89%). The proportion of respondents who currently identify as Christian has
been in decline in Czechia and Slovakia; meanwhile, the proportion of
respondents who currently identify as Christian has been stable or even
increased in the rest of the Central and Eastern European countries.
In Austria, between 1971 and 2021, Christianity declined from 93.8%
to 68.2% (Catholicism from 87.4% to 55.2% and Protestantism from 6% to
3.8%) while people with no religion rose from 4.3% to 22.4%. According to the 2021 national survey conducted by Statistics Austria,
among Christians, 80.9% were Catholics, 7.2% were Orthodox Christians,
5.6% were Protestants, while remaining 6.2% were Christians, belonging
to other denominations of the religion or not affiliated with any
denomination, and 22.4% declared they did not belong to any religion,
denomination or religious community.
In absolute terms, the Catholic Church
lists about 4.7–4.8 million members in 2022 (50–52% of the population).
In 2022. 90,808 Austrians formally left the Catholic Church in 2022 and
85,163 left in 2023. Between 2019 and 2023, Catholic baptisms and Catholic Weddings decreased from over 45,000 to ~39,000 and ~11,000 to ~8,000 respectively. A survey shows roughly 322–348 thousand attended Sunday Mass in 2023, down from over 500,000 in pre-pandemic attendance trends. The Catholic bishops cite "unfavorable ratio between baptisms and deaths" as the key driver for this change.
Self-identification with Christianity has been steadily declining in Finland. In 2025, 62.2% of Finns counted themselves as belonging to a Christian church, compared with 86.2% in 2000.
The number of church members leaving the Church saw a
particularly large increase during the fall of 2010. This was caused by
statements regarding homosexuality and same-sex marriage – perceived to
be intolerant towards LGBT people – made by a conservative bishop and a politician representing Christian Democrats in a TV debate on the subject.
Christianity has been declining in France
steadily since the 1960s. In 2021, a French poll showed that over half
of French citizens do not believe in God or consider Christianity to be
irrelevant. People who identified as Catholic declined from 81% in 1986
to 47% in 2020, while the number of people who identified as not
religious rose from 16% to 40%. In 2021, around 50% of all French respondents identified as Christians.
In 2024, it was estimated that about 48% of the German population
were Christians. About 45% were members of the two large Christian
churches. Attendance and membership in both Catholic and Protestant churches in Germany
have been declining for several decades. In 2021, for the first time,
fewer than half of German citizens belonged to the two larger churches.
According to some sources, Christianity is declining in Hungary.
Between 1992 and 2022, Christianity declined from 92.9% to 42.5%
(Catholicism from 67.8% to 29.2%). In 2022, only 35.5% of people with
age group 30-39 identified as Christians, the number further dropping to
32.8% of people with age group 20–29. Among Catholics, only 12% regularly attend church. On the other hand, a series of surveys conducted by Pew Research Center
in 2018 found that the share of Christians has remained fairly stable
in Hungary (75% who say they were raised Christian versus 76% who say
they are Christian now).
Catholicism remains the predominant religion in the Republic of Ireland. In the 2022 census, 75.7% of the population identified as Christian. However, recent social changes, including the lifting of a ban on abortion and the legalizing of same-sex marriage,
have accelerated a shift toward more secular or liberal attitudes in
Ireland, particularly within younger demographics. This increased
secularization is exemplified when comparing mass attendance, weekly
Mass attendance stood at 81% in 1990; this dropped to 48% by 2006. This process is characterized by scholars as a move toward a
"Post-Catholic" state, i.e. one from where traditional Catholicism,
which held a "monopoly on the Irish religious market" and had a strong
relationship with state power, is being displaced.
An Irish priest, Fr. Kevin Hegarty, asserted in 2018 that the church's authority was undermined by the papal encyclical, called Humanae Vitae, that established the Church's opposition to contraception. He reported that there is only one priest under the age of 40 in the entire diocese of Killala;
only two priests have been ordained over the last 17 years, and there
have been no candidates for the priesthood since 2013. Hegarty blames
this decline on the Church's positions on female ordination, contraception and sexuality. A continued requirement for children entering Irish Catholic-owned
schools to be baptized keeps the overall level of baptisms high, though
the number of individuals practicing a faith or attending church is
decreasing.
Problems arising from the sexual abuse of children
and the historical persecution of single mothers and their families
have also greatly contributed to the decline of Catholicism in Ireland. The clerical scandals and the poor handling of them damaged the Churches credibility.
Church converted into Belgian Beer Cafe in Utrecht, Netherlands.
The Netherlands has tolerated greater religious diversity among
Christian sects than Scandinavian countries, where "automatism" (default
registration in the Lutheran Church
by birth) has been the norm. Non-denominationalism increased in the
Netherlands during the 19th century. This process slowed between the
1930s and 1960s, after which non-denominational affiliation increased.
The Church's ministry to the poor was not needed in the modern
Netherlands that had developed systems of government welfare and secular
charity. The declining influence of religious institutions in public
life allowed great religious, philosophical and theological pluralism in
the private and individual spheres of Dutch society. During the 1960s and 1970s, pillarization
weakened as people became less religious. In 1971, 39% of the Dutch
population were Roman Catholics; by 2014, its share of the population
had dropped to 23.3% (church-reported KASKI data), or 23.7% (large
sample survey by Statistics Netherlands in 2015). The proportion of
adherents of Calvinism and Methodism declined in the same period from
31% to 15.5%.
In 2015, Statistics Netherlands,
the government institute that gathers statistical information about the
Netherlands, found that Christians made up 43.8% of the total
population. With only 49.9% of the Dutch in 2015 adhering to a religion, the Netherlands is one of the least religious countries of the European Union,
after the Czech Republic and Estonia. By the 1980s, religion had
largely lost its influence on Dutch politics, and as a result, Dutch
policy on women's rights, abortion, euthanasia, homosexuality and
prostitution became very liberal in the 1980s and 1990s. Subsequently,
the two major strands of Calvinism, the Dutch Reformed Church and the Reformed Churches in the Netherlands and a small Lutheran group, began to cooperate as the Samen op weg Kerken ('Together on the road churches'). In 2004, these churches merged to form the Protestant Church in the Netherlands.
In 2015, an opinion survey found that 63% of Dutch people thought that religion did more harm than good. A quarter of the people thought that morality would be threatened if no
one believed in God, down from 40% in 2006. The number of people
reporting that they never pray rose from 36% in 2006 to 53% in 2016. In 2015, Statistics Netherlands found that 50.1% of the adult population declared no religious affiliation.
In 2021 Polish census,
71.3% of Polish people identified as Catholic, although 20.53% refused
to answer the question about their religion. A 2022 poll showed that 84%
of Polish people identify as Catholic, but only 42% are practicing
Catholics, and among 18- to 24-year-olds only 23% are practicing
Catholics, compared to 69% in 1992. The Catholic sex abuse scandal and the large restrictions on abortions in Poland contributed to this decline in Catholicism among the younger generations.
Adherence to established forms of church-related worship is in rapid
decline in Italy and Spain, and Church authority on social, moral and
ethical issues has been reduced. Daily church attendance has declined, but Catholicism still remains the
predominant religion in Spain and Italy. However, according to the
Spanish Center for Sociological Research, 55.6% of Spaniards self-identified as Catholic in 2023, but only 18.3% claimed to be "practicing" Catholics.
In Italy, about 68% of participants in a 2023 poll by Ipsos self-identified as "Christians". However, although most of the population claims religious affiliations, according to the Italian National Institute of Statistics (ISTAT) data, less than 19% of Italians have declared themselves to be practicing. While the
proportion of those who have never practiced a religion has doubled,
from 16% in 2001 to 31% in 2022.
Attendance at Anglican churches had begun to decline in the United Kingdom by the Edwardian era, with both membership in mainstream churches and attendance at Sunday schools declining. Infant baptism declined after World War II. In 2014, Archbishop of CanterburyRowan Williams stated that the UK had become a "post-Christian country". That same year, only 4.3% of the population participated in a Church of England (C of E) Christmas service. Nevertheless, around 60% of all respondents still identified as Christians in the 2011 Census.
The Roman Catholic Church
has witnessed the highest retention rate among all Christian
denominations. In 2015, 9.2% of the UK population was Catholic.
According to scholar Stephen Bullivant, based on the British Social Attitudes Survey and European Social Survey,
the decline in Anglicanism has slowed thanks to "the return of
patriotism and pride in Christianity", and the number of followers of
the Anglican Church has increased slightly by 2017. This growth, however, is still below that needed and is mainly from
African immigrants. Anglicanism has been majority African since 2001. In
2017, a report commissioned by the Christian group Hope Revolution
indicated that 21% of British youth identified as "active followers of
Jesus".
According to the 2018 British Social Attitudes Survey
(BSA), 33% of over-75s identified as C of E, while only 1% of people
aged 18−24 did so. The report stated that "Britain is becoming more
secular not because adults are losing their religion but because older
people with an attachment to the C of E and other Christian
denominations are gradually being replaced in the population by younger
unaffiliated people."
In the 2022 Scotland census, for the first time, a majority of
people stated that they did not identify with any religion—51.1%, up
from 36.7% in 2011. However, according to a report by Bible Society, among 18- to
24-year-olds in the UK has increased from 4% in 2018 to 16% in 2024,
sparking conversations about a revival in the UK, especially after the COVID-19 pandemic.
A deconsecrated church in Australia, now in use as a restaurant.
Australia was a Christian majority nation, but lost the status between 2010-20s. The percentage of people belonging to some form of Christianity
decreased from 52.2% in the 2016 Census to 43.9% in the 2021 Census.
Meanwhile, those declaring that they had no religion increased from 30%
in the 2016 Census to 38.9% in the 2021 Census. In a 2017 survey of teenage Australians aged 13–18, 52% declared that
they had no religion, compared with 38% Christian, 3% Muslim, 2%
Buddhist and 1% Hindu.
In 2016 Census, the Pentecostal church was only form of Christianity to show growth, rising from 1.7% in 2011 to 2.1%. However, like other forms of Christianity, it also has declined in 2021 Census.
Trends in Religious Affiliation of New Zealand Across the Last Five Censuses (2001–2023).
In New Zealand, there has been a significant decrease in Christianity
and increase in the population declaring "No religious affiliation".
The reason for this is attributed to the decline in belief in
institutional religion and increase in secularism.
In the 1991 census, 20.2% of the New Zealand population followed "No religion". This share more than doubled over the next two decades, reaching 41.9%
in 2013 and rising further to 48.2% in 2018. By the 2023 Census, it had
climbed to 51.6%, surpassing the 50% mark for the first time. At the
same time, the Christian population declined from 47.65% in 2013 Census
to 37.31% in 2018 Census and finally 32.3% in 2023 Census. In the 2018
Census, the New Zealand population claiming "No religion" officially
overtook Christianity.
In 2008, Research by the Bible Society of New Zealand indicated
that only 15% of Christians attend church at least once a week, and 20%
attend at least once a month.
North America
Canada
Percentage of Christians per Canadian province or territory based on 2021 Census data
In 2021, Statistics Canada
found that only 68% of Canadians 15 years and older reported having a
religious affiliation, marking the first time the number had dipped
below 70% since StatCan began tracking religious affiliation in 1985. Christianity remains the largest religion in Canada; in the 2021 census, 53.3% of the population identified as Christians.
In Quebec, since the Quiet Revolution, over 500 churches (20% of the total) have been closed or converted for non-worship–based uses. In the 1950s, 95% of Quebec's population went to Mass; in the present day, that number is closer to 5%. Despite the decline in church attendance, Christianity remains the largest religion in Quebec, where 64.82% of people were Christians, according to 2021 census.
With the loss of Christianity's monopoly after having once been central and integral to Canadian culture and daily life, Canada has become a post-Christian and secular state.
Although Mexico is the second largest Catholic country in the world
in terms of members, Catholicism has been declining over the past 30
years, from 89.7% of the population in 1990 to 77.7% in 2020. The number
of Catholics in Mexico have decreased by 20.5% since 1950. In 2020, 8.1% of Mexicans did not identify with any religion.
The National Institute of Statistics and Geography (INEGI)
reported that the number of evangelicals or Protestants rose from 4.9%
in 1990 to 5.2% in 2000, reaching 7.6% in 2010, and 11.7% in 2020. The Institute estimates that 20 million Mexicans are evangelical. More than 17 million Mexicans are Pentecostal and Charismatic. There 8 million Christians independent from denominations in Mexico.
Christianity, the largest religion in the United States, experienced a 20th-century high of 91% of the total population in 1976. This declined to 73.7% by 2016 and 64% in 2022. The Evangelical Lutheran Church in America (ELCA) lost about 30% of its
congregation and closed 12.5% of its churches: the United Methodist
church lost 16.7% of its congregation and closed 10.2% of its churches.
The Presbyterian Church had the sharpest decline, losing over 40% of its congregation and 15.4% of its churches between 2000 and 2015. Infant baptism has also decreased; nationwide, Catholic baptisms declined by nearly 34%, and ELCA baptisms by over 40%. As of 2024, Christianity's decline may have leveled off or slowed, according to the Pew Research Center and Gallup, though according to the Public Religion Research Institute, it has continued to decline.
In a study published in 2022, Pew Research Center projected that
if the rate of decline continued to accelerate, Christians would make up
less than half of the American population by 2070, with estimated
ranges for that year falling between 35% and 46% of the American
population. In 2024, Pew Research Center published a study stating that the
percentage of American adults who identify as religiously unaffiliated,
known as "nones", numbered 28%, higher than Catholics at 23% and
Evangelical Protestants at 24%. However, Pew reported in 2025 that Christianity's decline has begun to
"slow…or level off." Some speculate that a revival of Christianity has
begun in the U.S.
In 2019, 65% of American adults described themselves as Christians. In 2020, 47% of Americans said that they belonged to a church, down
from 70% in 1999; this was the first time that a poll found less than
half of Americans belonging to a church. Nationwide Catholic membership increased between 2000 and 2017, but the
number of churches declined by nearly 11% and by 2019, the number of
Catholics decreased by 2 million people, dropping from 23% of the population to 21%. Since 1970, weekly church attendance among Catholics has dropped from
55% to 20%, the number of priests declined from 59,000 to 35,000 and the
number of people who left Catholicism increased from under 2 million in
1975 to over 30 million today.
In 2022, there were fewer than 42,000 nuns in the United States, a
76% decline over 50 years, with fewer than 1% of nuns under age 40. The Southern Baptist Convention
has experienced decline: between 2006 and 2020, it lost 2.3 million
members, representing a 14% decrease in membership during that period. The Lutheran Church – Missouri Synod reported in 2021 that the denomination has been declining in membership. In 2020, the church reported approximately 1.8 million total baptized
members, a decline from its peak in 1971 when it reported nearly 2.8
million total baptized members.
The 2014 Religious Landscape Study found a large majority of
those who were raised as Christians in the United States still identify
as such (retention rate of 87.6% among those raised Christian), while
those who no longer identify as Christians mostly identify as
religiously unaffiliated. More recent studies have found a retention rate closer to 67%, with
one-third of those who were Christian in childhood leaving the religion
by age 30. The 2014 study found that 84% of all adults who were raised as historically Black Protestant continue to identify as such or identify now with different Christian denominations, Evangelical Protestant (81%), Mormon (76%), Catholic (75%), Orthodox Christian (73%), mainline Protestant (70%), and Jehovah's Witnesses (62%) continue to identify as such or identify now with different Christian denominations. Significant minorities of those raised in nearly all Christian denominational families now say they are unaffiliated, ranging from 13% among those raised historically Black Protestant to 35% of those raised Jehovah's Witnesses. A small minority of those raised in nearly all Christian denominational
families identify now with another faith, ranging from 3% among those
raised historically Black Protestant, Evangelical Protestant, Mormon,
Orthodox Christian, and Jehovah's Witnesses to 4% of those raised
Catholic and mainline Protestant. A 2022 Pew Research study found that 30% of Latinos in the United
States were religiously unaffiliated, and half of Latinos age 18–29 were
religiously unaffiliated.
Moderate and liberal denominations in the United States have been
closing down churches at a rate three or four times greater than the
number of new churches being consecrated. However, according to The Christian Century,
the rate of annual closures is approximately 1% and quite low relative
to other types of institutions. It has been asserted that of the
approximately 3,700 churches that close each year, up to half are
unsuccessful new churches. The more conservative evangelical denominations have also declined, representing 23% of the population in 2006 and 14% in 2020 according to the Public Religion Research Institute.
The Public Religion Research Institute's 2020 Census of American Religion showed that the overall decline of white Christians in America had slowed, stabilizing at around 44% of the population. It also showed that, contrary to expectations, white evangelicals had
continued to decline and that they were now outnumbered by white
mainline Protestants. Conversely, the Pew Research Center found in 2022 that the decline had continued to accelerate over the previous fifty years.
South America
Historically, South America was dominated by a 'Catholic monopoly', with the Roman Catholic Church
exercising strong influence over religious, social, and political life.
In recent decades, however, scholars have described the region's
religious landscape as having shifted toward a more competitive and
pluralistic 'religious marketplace'. While Christianity remains the dominant religion, the region has experienced a significant decline in the proportion of Catholics, a surge in Evangelical and Pentecostal movements, and a notable rise in the non-religious population.
Some scholars have described the Catholic Church
in this era as a kind of 'complacent monopolist' that depended heavily
on cultural traditions and legal protections, rather than putting much
effort into active evangelization to retain its followers. Between 1996 and 2013, the proportion of Catholics declined in most
South American countries, with the sharpest drops recorded in Uruguay.
Although, South America remains overwhelmingly Christian, people who say they have no religious affiliation (irreligion) has been growing noticeably, especially in the Southern Cone. Uruguay stands out as the most secular country in the region. Between 1996 and 2013 the share of irreligious people there rose from about 18% to 38%. Chile
has seen a similar trend. Researchers largely trace this shift to
younger generations being much less religious than their parents. Sociologists are divided over whether this is real secularization or simply people drifting away from institutional religion. Some argue that even as the official Church weakens, Christian religiosity and its worldview still shapes everyday life for many.
As of 2019, Catholicism in Argentina was around 63%, down from 76.5% in 2004.Irreligiosity grew from 12% to 19% in 9 years.
A 2019 survey made online by the Universidad de San Andrés showed
that 76% of Argentinians believed in God (a decrease from 91% in 2008),
44% believed in heaven, 32% believed in hell, around 29% prayed daily,
only 13% attended religious services weekly and about 24% considered
religion to be very important in their lives.
However, affiliation with Protestant churches is increasing, as of 2019, Protestantism in Argentina was around 15.3%, rose from 9% in 2004. While Pentecostal churches originally attracted mostly the lower class,
they show an increasing appeal to the urban middle class. Middle-class congregations develop a distinctive style of Pentecostalism, more adapted to society.
Cases of sexual abuse, attempts to hide information, and interference
in government affairs are suggested as the main causes of the decline
of Christianity in Chile. According to the public broadcaster TVN, the number of Chileans who declare themselves Catholics fell from 73% in 2008 to 45% in 2018. In addition, it is the Latin American country that has less trust (36%) in the Church throughout the region according to Latinobarómetro. 63% of the Chilean population profess some branch of Christianity, according to the Encuesta Nacional Bicentenario identifies as Christian, with an estimated 45% of Chileans declaring to be part of the Catholic Church and 18% of Pentecostal churches. 5% of the population adhere to other religion.
Attempts to restore the Roman Catholic Christian faith in Chile have failed. The Argentine newspaper Clarín reported that Pope Francis's State visit to Chile in 2018 "had been the worst in his five years of pontificate." After the papal visit, the crisis in the Chilean Catholic Church increased. According to the Bicentenario
survey, atheism has grown from 21% in 2018 to 32% in 2019 and then to
36% in 2020 and 37% in 2021. Despite the decline of Roman Catholic
Church, Pentecostalism still maintains the same percentage of adherents since 2012.
According to the 2025 Pew survey, Christianity ceased to be the
majority faith in the United Kingdom, Australia, France, and Uruguay,
where it had previously been the dominant religion.
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