Encephalitis is inflammation of brain. It is a viral disease. It may be caused by herpes simplex virus or rabies virus. Common symptoms include a headache, fever, confusion, vomiting, seizures, hallucinations, etc. Kala-azar disease is also known as Visceral leishmaniasis. It is caused by parasite Leishmania donovani and transmitted by sand fly Phlebotomus argentipes. The larval stage of Ascaris lumbricoides is called as Rhabditiform larvae as it appears similar to soil nematode, Rhabditis found in soil and human faeces. 

AIDS day is celebrated on 1st December. AIDS was first reported in 1981 and in last twenty-five years or so, it has spread all over world killing more than 25 million people.