Pope Francis' high-stakes sex abuse prevention summit is meant to call attention to the crisis as a global problem that requires a global response.
His decision was sparked by the realisation that in many parts of the world, bishops and religious superiors continue to deny or play down the severity of the scandal and protect their priests and the reputation of the church at all costs.
Much of the developing world has largely escaped a public explosion of the scandal, as have conflict zones and countries where Catholics are a minority.
But even majority Catholic countries have lagged. Just this week, the online resource BishopAccountability listed Brazil, Mexico, the Philippines, Congo and a handful of other heavily Catholic countries as places where the church leadership has failed to respond adequately when priests rape and molest children.
Some countries where the scandal has played out visibly in recent years:
Francis' home country is beginning to see an eruption of the scandal, with some cases even implicating the pontiff himself.
As Cardinal Jorge Mario Bergoglio, Francis played a decisive and divisive role in Argentina's most famous abuse case, commissioning a four-volume, 2,000-plus page forensic study of the legal case against a convicted priest that concluded he was innocent, that his victims were lying and that the case never should have gone to trial.
Despite the study, Argentina's Supreme Court in 2017 upheld the conviction and 15-year prison sentence for the Rev. Giulio Grassi, a celebrity priest who ran homes for street children across Argentina.
More recently, an Argentine bishop close to Francis, Bishop Gustavo Zanchetta, was placed under investigation for alleged sexual misconduct. Francis had brought Zanchetta to the Vatican and given him a high-ranking job after he resigned suddenly from his post in 2017. The Vatican insists no allegation of sexual abuse was lodged until last year, but local church officials said they raised the alarm about inappropriate behavior in 2015.
Australia's Catholic Church has a horrific abuse record, which in part prompted the government to launch a four-year national investigation into all forms of institutional abuse — Catholic and otherwise.
The landmark survey found 4,444 people were abused at more than 1,000 Catholic institutions between 1980 and 2015.
The Royal Commission investigation, Australia's highest form of enquiry, deduced that 7 percent of Catholic priests in Australia between 1950 and 2010 had been accused of sexually abusing children.
Francis discovered first-hand just how pervasive clerical sex abuse is — and how effectively it has been covered up by the Catholic hierarchy — when in January 2018 he branded as "calumny" accusations of cover-up against a Chilean bishop he had strongly defended.
After realising his error, Francis did an about-face: He ordered a Vatican investigation, apologised in person to the victims he had discredited, and strong-armed the entire Chilean hierarchy to tender their resignations.
It wasn't enough. Chilean criminal prosecutors have staged a series of raids on the church's secret archives to seize documents. They have opened more than 100 investigations into abusive priests and have questioned the current and former archbishops of Santiago about allegations they covered up the crimes.
One of France's most prominent cardinals, Philippe Barbarin, went on trial this year on charges he covered up for a known paedophile. Prosecutors, however, have asked for the case to be dropped since the statute of limitations has expired.
Barbarin and five other French defendants were accused of knowing that the Rev. Bernard Preynat sexually abused young scouts but didn't report him to police. Preynat, now in his 70s, has confessed in letters to victims' parents and meetings with his superiors, including Barbarin.
Barbarin, 67, has admitted to "mistakes" in the management and nominations of priests, but has denied any attempt to cover up the Preynat case.
In September, the German Catholic Church released a devastating report that concluded at least 3,677 people were abused by clergy between 1946 and 2014.
More than half the victims were 13 or younger and most were boys. Every sixth case involved rape and at least 1,670 clergy were involved. Some 969 abuse victims were altar boys.
While the report was an effort at transparency, the researchers who compiled it complained they didn't have access to original files, and said there was evidence that some files were manipulated or destroyed.
Judge-led investigations have produced four mammoth reports since 2005 into the church's wretched record in dealing with predator priests, helping to dismantle the Catholic Church's once- dominant influence in Irish society and politics.
The reports have detailed how tens of thousands of children suffered wide-ranging abuses in church-run workhouse-style institutions, how Irish bishops shuttled known paedophiles throughout Ireland and to unwitting parishes in the U.S. and Australia, and how Dublin bishops didn't tell police of any crimes until forced by the weight of lawsuits in the mid-1990s.
One of the final investigations, into the diocese of Cloyne, found that officials there were still shielding suspected paedophiles from the law until 2008 — more than 12 years after the Irish church unveiled a policy requiring the mandatory reporting of all suspected crimes to police.
That policy, however, was rejected by the Vatican in 1997 as undermining canon law — a position that, combined with the Vatican's refusal to cooperate in the Irish fact-finding probes, prompted the Cloyne enquiry to find the Vatican itself culpable in promoting the culture of cover-up.
Clergy sex abuse in the Vatican's backyard has long been a taboo subject, but that is beginning to change.
Earlier this month, Italy was taken to task for its failure to properly police the Catholic Church by the U.N. Committee on the Rights of the Child. The committee called for an independent enquiry into what it said was the abnormally low number of investigations and prosecutions of child sex abuse committed by priests.
In Italy, there is no legal requirement for clergy to report suspected sexual abuse to police.
After the abuse scandal erupted in Boston in 2002, U.S. bishops adopted the toughest anti-abuse norms in the Catholic Church, a "one strike and you're out" policy that removes any priest from ministry if he commits a single act of abuse that is admitted to or established.
The norms require dioceses to report allegations to police and have a lay-led review board to receive and assess claims.
The U.S. scandal was revived in June with revelations that one of the cardinals who drafted the 2002 policy, the retired archbishop of Washington, Theodore McCarrick, himself had been accused of molesting at least two minors as well as adult seminarians.
Just last week, Francis defrocked McCarrick after a Vatican tribunal found him guilty of misconduct with minors, adults and soliciting sex during confession. He hasn't commented on his conviction.
The scandal exploded anew in August with the Pennsylvania grand jury report finding some 300 priests sexually abused at least 1,000 children in six dioceses since the 1940s. Since then, prosecutors in more than a dozen U.S. states have announced similar investigations.
While only a few hundred people live in the world's tiniest sovereign state, Vatican City's criminal jurisdiction covers the Holy See's global diplomatic corps, and two priestly diplomats have faced trial in recent years.
In 2018, the Vatican tribunal convicted Monsignor Carlo Capella of possession and distribution of child pornography and sentenced him to five years in prison. Capella admitted to viewing the images during a period of "fragility" and interior crisis sparked by his job transfer to the Vatican Embassy in Washington.
In 2013, the Vatican charged its then-ambassador to the Dominican Republic, Monsignor Jozef Wesolowski, with sexually abusing young boys. Wesolowski was defrocked by the Vatican's church court, but he died before a criminal trial got underway.
Just last week, a third diplomat was placed under investigation in France for alleged "sexual aggression." The Vatican has acknowledged seeing reports of the investigation into its ambassador to France, Archbishop Luigi Ventura, but has not commented further.
The Vatican City State has no policy on its books to protect children or require reporting of sex crimes to police.