As COVID-19 cases piled up in several current hot spots, such as Latin America, the United States, and India, countries such as Vietnam and Greece that have brought their disease levels down scrambled to target flare-ups with stepped-up measures.The global total today passed the 16.5 million mark, reaching 16,540,137 cases and 655,300 deaths, according to the Johns Hopkins online dashboard.Hot spots pose continuing challengesIndia today reported nearly 50,000 cases, and in Latin America, Mexico recently passed Peru as the Latin American country with the second highest number of cases, behind Brazil, which reported about 23,500 cases yesterday amid early signs of its outbreak stabilizing.Two presidents of Latin American countries who were