गुसु आरो गोरान बोथोरा मोदोमनि बायजोआव भाइरासखौ गुबुन थासारिफोरनिख्रुइ गोबावसिन थावरिहोनो हायो, गोजां-बोथोराव दुंब्रुद ओनसोलफोराव मोनसे जाउन, बोथोरारि महामारिफोर हिसाबै नुजायो।
Cold and dry weather enables the virus to survive longer outside the body than in other conditions and, as a consequence, seasonal epidemics in temperate areas appear in winter.