There is a good reason why so many people suffer from English fever. English has become the world's second language, the world's lingua franca. In fact, it is safe to say that it is difficult in today's world to be active and successful in international business, politics, scholarship, or science without considerable competence in English.
Possibly the best overall indication of the dominance of English is the internet. Without question, English has become the language of science.
The usual approaches to English fever are to offer English to very young children (and sometimes require it) and to provide a lot of it.