(CNN) American Catholics' faith in the church and clergy has fallen sharply in the last year, according to a new Gallup survey, as the church struggles to regain credibility amid a damning sexual abuse scandal.

In 2017, nearly half of Catholics in the US (49%) told pollsters they had a "high" or "very high" opinion of the honesty and ethical standards of clergy members. In December of 2018, at the end of the church's "year from hell," that number had dropped to 31%.

In 2018, a prominent cardinal resigned in disgrace, grand jurors in Pennsylvania accused 300 Catholic clerics of secretly abusing children over the past 70 years and a former Vatican ambassador urged the Pope himself to step down. And the clergy sex abuse scandal shows no signs of abating, with a federal investigation and ongoing probes in at least 12 states and the District of Columbia.

Most of the alleged abuse, particularly in the grand jury report, occurred before the US Catholic bishops instituted new protocols in 2002 in which they pledged to report to civil authorities all cases of clergy accused of abusing minors.

"The church's credibility has been seriously undercut and diminished by these sins and crimes," Pope Francis told the US Catholic bishops earlier this month , "but even more by the efforts made to deny or conceal them."

"God's faithful people and the Church's mission continue to suffer greatly as a result of abuses of power and conscience and sexual abuse, and the poor way that they were handled, as well as the pain of seeing an episcopate (body of bishops) lacking in unity and concentrated more on pointing fingers than on seeking paths of reconciliation," he added.

The Pope has convened a meeting of bishops from around the world in Rome for February 21-24, saying he wants the church to tackle the scandal together. But, according to Gallup, American Catholics appeared to be losing confidence in the church even before the sexual abuse scandal.

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In June of 2017, more than half (52%) of American Catholics professed a "great deal" or "quite a lot" of confidence in the church or organized religion, according to Gallup. A year later, that number had dropped to 44%. Pennsylvania's grand jury report was released in August.

The survey doesn't ask specifically about Catholic or Protestant clergy, lumping them all together as "clergy," but it's reasonable to assume that Catholics were talking about Catholic clergy, Gallup says, particularly since there have been large drops in Catholics' views of clergy members' ethics several times over the past 20 years, each time after a new sexual abuse scandal in their church has come to light.

General trust in clergy falling

All Americans' trust in clergy -- Catholic and otherwise -- has been falling since 2012, Gallup says. Overall, though, Protestants are more likely to have positive views of the clergy and their church. Nearly half (48%) have "high" or "very high" views of clergy members' honesty and ethical standards, and nearly an identical number profess faith in "the church/organized religion" in general.

Despite the decline in trust of their church and its clergy, American Catholics' percentage of the population has been holding steady at about 22%, Gallup found, while identification with Protestant traditions has "dropped precipitously" in the last decade.

Much of the church's stability can be traced to Latino immigration, Gallup says. Three in 10 American Catholics are now Latino, who make up 15% of the American population at large.

Despite their church's troubles, a slight majority of Catholics (52%) still say religion is "very important" in their lives, a number that has stayed relatively stable since 2001, Gallup says.