'Infectious disease' or ID is the science that studies diseases caused by pathogens such as bacteria, viruses, parasites, or fungi that can harm the human health. Infectious disease specialist is responsible of diagnosing and treating infectious disease. The doctor conjointly takes care of administering preventive procedures like vaccines to combat infections. Among the diseases most frequently treated by the specialist embrace infectious diseases, sexually transmitted infections caused by bacterium like syphilis and lymphogranuloma venereum, and viral like HPV and hepatitis, parasitic like scabies, or fungal infection like candida. Others embrace malaria, pelvic inflammatory disease, and microorganism vaginosis.