Eastern Visayas, the poorest island in the Phillipines, teams of wandering Communist guerrillas administer acupuncture to victims of tuberculosis and pneumonia, the two greatest killers in this archipelago nation. Virtually no other medical treatment is available.

In Metro Manila,the brassy, husting capital area governed by Imelda Marcos, the wife of President Ferdinand E. Marcos, a palatial $50 million heart center stands all but empty. The fabulously wealthy of the metropolitan area, the only ones who can afford treatment in the center, prefer to fly to the United States to be treated.

It is this juxtaposition of urban wealth and rural neglect that has provided ferment for protracted socail unrest and pitted Marcos' marshal law regime against Communist-led guerrillas.

In a sense, United States seems to be symbolically associated with the urban wealth. Looking at the neon lights of the capital's Makati commercial center American visitors have little difficulty imagining that they are back home: Ford, Chrysler, General Motors, Coke, Pepsi, Procter and Gamble, Colgate-Palmolive, Goodyear, B.F. Goodrich, Firestone, IBM, Xerox, National Cash Register, and more.

A roll through the fabulous Green Hills or Harison Plaza shopping malls drives the message home again: endless rows of shelves crammed with familiar names in breakfast cereals, instant coffee, cigarettes, canned and frozen foods, the Shakey's pizza parlors, the A and W root beer stands. MacDonalds hamburgers are on the way.

For the Communist guerrillas of the New Peoples Army, the inequities of medical, educational and other basic services between country and city, rich and poor, and the powerful U.S. influence here, have fueled their running battle with Marcos.

From all available evidence, the battle is going against the Communists. Most of their senior guerrilla and political leaders are under arrest and facing martial law tribunals. The powerful Philippines army and constabularly are on the offensive in most Communist strongholds.

In a crowded auditorium on a military base that is serving as a make-shift courtroom, the man charged by the government with being the commander-in-chief of the New People's Army, Bernable Buscayno, conceded the group's weakened position.

He claimed, however, that by concentrating on helping those Fillpinos ignored by the regime, the landless peasants and the poor urban workers, the Communists were gradually succeeding building popular reaction against Marcos.

"Martial law is hindering us, no doubt," said Buscayno, but he insisted that political repression would eventually act "like a dam - building up water until it bursts through."

Meanwhile, he said, the Communists would continue to fight the Marcos regime and its U.S. "backers" with popaganda and hit-and-run guerrilla tactics.

"As long as the United States maintains military bases in our country over which the Filipino p+ople have no authority and as long as American and other multi-national corporations control ourselves independent," he said.

Buscayno, whose guerrilla name is "Commander Dante," is undergoing a military trial along with 55 other alleged Communists, several of whom are considered to be senior guerrilla and party leaders.

Their detention has not prevented the Communist insurgents from waging nagging small-scale attacks on government units. Late last month, for example, about 30 guerrillas ambushed two separate police patrols near the U.S. Naval Base of Subic Bay and killed six militiamen. A few days later, in a raid outside the U.S. Clark Air Base, the Communists killed two Filipino civilians, one believed to be a rebel turncoat.

A U.S. source said the insurgents have never attacked any of the U.S. bases in the Philippines or the 17,000 U.S. servicemen on them.

In addition to the 56 being tried, the government has issued charges against 36 other alleged Communists who are listed as still being "a large." All 92 ar charged with a variety of crimes linked to rebellion, including receiving weapons from China.

In a recent interview during a break in the hearings, Buscayno conceded that the arrests, most of which took place last year, were a serious blow. But he claimed mounting dissatisfaction with martial-law restraints favors the Communists.

Buscayno's allegation that the Philippine economy is dominated by U.S., Japanese and other foreign firms is heard frequently in Manila. It is a popular theme among university students, who have recently grown more outspoken after five years of martial law, and among a small but vocal segment of the Roman Catholic Church.

The Communists reportedly have failed, however, in their attempts to join forces with Moslem separatists on Mindanao, in the southern Philippines.

According to an informed Western diplomatic source, the Moslem separatists whose strength lay in the far south, found the appeal of the Maoist-oriented Communists "repugnant to their regilious sensibilities."

Conversations with several Catholic clergymen indicated, however, that radical elements in the church are supporting the Communists. Two priests who work among a minority tribal group in the northern island of Luzon said that their parishioners had been "bitterly offended by the army's insensitivity and arrogance" to their traditions.

The guerrillas, on the other hand, "have proven themselves to be of the people and frequently provide practical assistance in their everyday lives," one of the priests said.

This view supported Buscayno's claim that the Communist insurgents were largely confining their military activity to defending themselves while concentrating their efforts on "mobilizing and educating the poor farmers and workers."

This kind of allegation is seldom seen in Manila's tightly controlled newspapers. But in an extraordinary series that began this week in the Evening Post, a reporter wrote from the eastern island of Samar that a "vexing and potentially explosive battle for the hearts and minds of the masses" is being waged there between the Communists and the government.

As "causes of social grievances," the reporter cited "indifference of local government officials, bureaucratic abuses, unemployment, massive poverty, rampant criminality, lack of health service facilities and a pervasive sense of neglect." Buscayno will not be allowed to see this or any other newspaper, but the article would come as no surprise to him.

As the gaunt, 33-year-old Buscayno spoke in his first interview with a foreign journalist, a military officer attached to the tribunal stood alongside him. The officer made no effort to interfere, but Buscayno's lawyer advised him not to discuss his own case.

Buscayno, who was arrested with his pregnant wife 13 months ago, refused to comment on the group's armed strength. He only said that after beginning in 1969 with 35-guerrillas, it rose to 3,000 by 1972, when Marcos imposed martial law.

Western military experts estimate the Communists present strength at about 2,000 guerrillas. Buscayno said they had not "liberated" any territory. "We don't make any effort to hold or control any areas because this would lead to decisive engagements and we would lose the war. In the present conditions here, we have no intention of launching a war."

He claimed that the guerrillas had the "support" of half a million people throughout the country and in certain areas of central Luzon they could hold open meetings without fear. Some Western analysts believe this is a gross exaggeration, but several of these sources agreed that the Communists were gaining support among tenant farmers and landless farm laborers.

As to the government's claim that they were receiving arms from China, Buscayno said, "We don't ask or expect support from fraternal parties. Perhaps we receive political and ideological support. But that's all."

The son of a plantation overseer who had 18 children, Buscayno is one of the few Philippine Communist leaders with genuine peasant roots. His formal education ended after two years to high school while most of his young party colleagues are university graduates.

"I studied Marx on my own," he said, "and learned how to analyze the Philippines' situation through his writings. I'm absolutely convinced that my views are current."