Use
PacketPlayOutAnimation for each player with the value "2". This will have players still be in survival but puts them in adventure mode client-side which means no more block glitching :p but, you're still able to place down items (aka redstone torch).

When infection starts:

Code:

        players.stream().map(this::getEntityPlayer).forEach(ep -> ep.playerConnection.sendPacket(new PacketPlayOutAnimation(ep, 2)));

EntityPlayer getEntityPlayer(Player p){ return ((CraftPlayer)p).getHandle(); }

When a player joins Infection:

Code:

        EntityPlayer ep = getEntityPlayer(p);
        ep.playerConnection.sendPacket(new PacketPlayOutAnimation(ep, 2));

This basically makes it look like you are in adventure mode when you are actually in survival.