A sharp surge in COVID-19 cases brings the prospect that Brazil will have the most infections and deaths in the pandemic worldwide, deepening the challenges for the country's reshuffled government.

A particular concern is the P.1 strain of the novel coronavirus, which is spreading rapidly in the largest and most populous country in Latin America, experts said.

Against this backdrop, Brazil has had four health ministers since the pandemic started, and on Monday, the ministers of foreign relations and defense resigned.

Since the beginning of the year, cases among people aged 30 to 59 have risen more than 600 percent and the number of deaths tripled. As of Monday, Brazil was logging more than 100,000 new cases per day and the seven-day average of deaths had risen to 2,595.

The total death toll has reached 317,646, with deaths on Tuesday hitting a single-day record of 3,780.

"Unfortunately, people have become immune to the numbers. Hundreds dying per day was terrible, a thousand dying per day was of great concern, but several thousand dying per day has become old news," said William Magnusson, a researcher based in Manaus.

Manaus, some 2,000 kilometers from the capital Brasilia, is in the heart of the Amazon. The P.1 strain was first identified there on Jan 12.

The strain spread rapidly, prompting Brazil's neighbors to close their borders.

"The P.1 strain was identified in at least 70 percent of the cases in Sao Paulo and in Rio Grande do Sul, the state (that borders) Uruguay," said Jorge Kalil, a professor of clinical immunology and allergy at the University of Sao Paulo.

With restrictions widely flaunted, it will be difficult to slow down the virus.

Brazil has topped 12.5 million infections and pressure is mounting on the government to take more effective measures.

'Worst moment'

Marcelo Brisolla, a Rio de Janeiro-based lawyer and a consultant for the life sciences sector, said Brazil is passing through "the worst moment of the pandemic".

Hugo Nogueira, an international relations analyst based in the city of Belo Horizonte, noted that Brazil's President, Jair Bolsonaro, has moved away from his longstanding denial and has begun acknowledging the pandemic.

Protesters were out in full force on March 24, banging pots and pans to protest the government's approach and slow vaccination campaign.

The resignations prompted a sweeping cabinet reshuffle that saw Bolsonaro replace six of his ministers.

Following the reshuffle of the cabinet, the chiefs of the armed forces resigned on Tuesday.

Complicating the country's response have been shortages of various medical supplies, including ventilators and drugs, to keep patients intubated, and even bottles of oxygen.

Brazil started its vaccination campaign against COVID-19 on Jan 17, with a batch of more than 10 million vaccine doses sourced by Sao Paulo State from China's Sinovac Biotech company. The federal government is distributing a vaccine developed by AstraZeneca and the University of Oxford.

The writer is a freelance journalist for China Daily.