Edit in JSFiddle

var _html = '<div class="list"><label><input type="checkbox" checked class="selectAll"> Countries</label>';

var _list = ['USA','India','China','England','Japan'];

for ( var i = 0; i < _list.length; i++ )
{
_html += '<div class="checkbox"><label><input type="checkbox" checked class="checkbox" value="' + _list[i] + '"/>' + _list[i] + '</label></div>';
}
_html += '</div>'
$('.wrapper').after(_html);


//select all and deselect all disease checkbox
$('.selectAll').change(function(){
  $(".checkbox").find(':checkbox').prop("checked", this.checked);  
});

$(".checkbox").change(function(){
		var _totalChecked = $('.checkbox').find('input:checked').length;
	if(_totalChecked == _list.length){
	 $(".selectAll").prop("checked", true);
	}else{
	 $(".selectAll").prop("checked", false);
	}
});



	
    

<div class="wrapper"></div>