A surge of refugees from Eastern Europe seeking asylum in the West is puzzling Western officials, who speculate that it could reflect worsening times in the East or be an unexpected side-effect of East-West detente.

The marked increase in defectors seems beyond dispute.

Karl Radek, director of the large refugee camp at Traiskirchen in neutral Austria, said in a telephone interview that in eight or nine weeks this summer, about 1,500 Czechoslovakians alone passed through his camp, the largest number in a short period since the Soviet invasion of Prague 11 years ago.

This influx, along with smaller numbers from other Soviet-bloc countries, took place as a little-noticed sidelight to a major flap in Eastern Europe this summer.

It was touched off early in August when Romania suddenly announced that foreign tourists would have to pay for gasoline with Western money. The ruling by the maverick communist state caused outrage in the rest of the Eastern bloc and long traffic jams at borders. Each year, about a million East European tourists travel through Romania to the Black Sea beaches of Bulgaria.

To defuse the problem, the governments of Czechoslovakia, Poland and Hungary allowed citizens already under way to travel through neighboring Yugoslavia instead, without visas. Yugoslavia, although a communist country, is outside the Soviet bloc and liberal by communist standards. Several hundred families took the opportunity to flee from there into Austria and Italy.

The Eastern bloc shut off these special travel permits by the end of September, but defections have continued.

Some have been widely publicized, such as the two East German families who escaped to West Germany in a hot air balloon, the pair of Soviet skating stars who defected in Switzerland, and three well-known Soviet ballet dancers who defected in the United States.

But there have been many others.

In northern West Germany, four busloads of Polish soccer fans were returning home Oct. 19 from a game in Holland. At a rest stop, 24 of them slipped away and asked for asylum.

On Sept. 29, the best-known sculptor in Bulgaria, 77-year-old Lyubomir Dalchev, and his family quietly decided to stay in the West after an exhibition in Vienna.

This week a 36-year-old Soviet technician asked for asylum in Sweden.

The Swiss government announced it had granted political asylum to a ranking Czechoslovak tennis player, Hana Strachonova, 18.

A Soviet journalist in Tokyo defected last week.

The emigration of cultural figures from East Germany has continued as author Guenther Kunert and actor Armin Mueller-Stahl left for West Germany.

Western officials here and in Austria who keep track of these developments have no easy explanation for the upsurge, although the Romanian gasoline crisis provided what Radek calls a special opportunity for people who may have toyed with the idea of defecting for years but otherwise might not have dared.

Undoubtedly, officials say, a generally worsening economic situation and rising prices in many East European countries has produced doubts about the future.

"I think it's economics plus," said one experienced diplomat. "And the plus is the key. What you see now is a sprinkling of people from everywhere. It's not just that it's Czechoslovakia. In many cases, they are also just ordinary people, not stars, and so one can perhaps think it is because they feel they haven't much hope."

Another diplomat talked of uncertainty about what he called the end of the Brezhnev era in the East and of growing alienation of some youth.

Nico Huebner, a young East German who received a jail sentence for refusing to serve in the Army, recently told a press conference after he was allowed to leave for the West that large numbers of East Germans his age had turned away from the East German brand of socialism.

Another official suggested that the East's widespread use of forced exile to get rid of dissident intellectuals -- apparently on the basis that they are less harmful to the Eastern governments once in the West and out of their native element -- may not be a factor.

In this view, it is probably true that people like exiled Soviet author Alexander Solzhenitsyn are less powerful critics speaking from the West than the East. But, the official said, it may be that the intellectual movement in the East is larger than assumed and forced exile will not cancel it out.

Several officials said the exodus is part of the general liberalization that has gradually unfolded through detente in Europe in recent years.

Travel restrictions in Poland, for example, have been loosened, as the Austrian camp director Radek pointed out. Travel between East and West, steadily is increasing.

The information and cultural explosion is abetted, according to some officials, by visitors, television and higher quality short-wave radios that receive British and West German programs.

Thus, these officials say, while repression continues in some countries, especially in Czechoslovakia, general relations between East and West are becoming more open.