Lauded in the early stages of the pandemic for taking decisive steps to limit Covid-19 infections, South Africa is now battling one of the world’s fastest-growing coronavirus outbreaks that is overpowering hospitals and has caused a dramatic increase in deaths. Public schools, which partially reopened in early June, will close for four weeks starting Monday, as the country enters a peak-infection period that models suggest could stretch into September. Africa’s most developed economy now has confirmed 434,200…