Table 16.1.
Classification of viruses with notable examples.
| Virus group | Illness (major signs) | Incubation | Duration | Remarks |
|---|---|---|---|---|
| Respiratory viral infections | ||||
| Rhinovirus | Common cold, sneezing, coughing, sore throat, and mild headache | 12–72 h | 2 weeks | As soon as immune cells invades the local area it becomes inflamed |
| Seasonal influenza | Acute respiratory infection, flu, severe fatigue, and body aches | 1–3 days | 5–7 days | Antigenic makeup of virus gets significantly changed |
| Respiratory syncytial virus (RSV) | Airway and lung infection, cough, and sneezes | 2–8 days | 1 days | RSV is a single-stranded enveloped RNA paramyxovirus |
| Viral skin infections | ||||
| Molluscum contagiosum virus (MCV) | Flesh-colored bumps | 2–7 weeks | 1 week to 6 months | MCV only replicates in human keratinocytes |
| Varicella-zoster virus (VZV) | Cold sores and genital herpes | 14–16 days | 10–21 days | It is a DNA virus of herpes virus group |
| Herpes simplex virus-1 (HSV-1) | Chickenpox, fatigue, itchiness, oozing blisters, and high fever | 2–12 days | 10 days | Transmission of HSV-1 virus is mainly through oral-to-oral contact causing oral herpes or cold sores |
| Foodborne viral infections | ||||
| Hepatitis A | Affects the liver, nausea, vomiting, diarrhea, and yellow skin | 14–28 days | 15–50 days | Transmission of virus is through fecal-oral route |
| Norovirus | Gastroenteritis, vomiting, and diarrhea | 12–42 h | 24–60 h | It is a small virus containing RNA surrounded by protein coat |
| Rotavirus | Stomach flu, dry mouth, and throat | 2 days | 2–8 days | It is a nonenveloped, double-shelled wheel-like appearance viruses |
| Sexually transmitted | ||||
| Human immunodeficiency virus (HIV) | Attack T cells of immune system, rapid weight loss, night sweats, tiredness | 1–4 weeks | 9 months to 20 years or longer | Leading to acquired immune deficiency syndrome (AIDS) |
| Human papillomavirus (HPV) | Increases risk of cervical cancer, genital warts, or precancerous lesions | 2–3 months | 2 years | It is a DNA virus from the papillomavirus family |
| Hepatitis B | Inflammation of liver, vomiting, diarrhea, jaundice, abdominal pain | 75 days | 30–180 days | Transmission of virus is through exposure to infectious blood or body fluids |
| Genital herpes or herpes simplex virus (HSV) | Cold sores, myalgia, headache, malaise, urethral, and vaginal discharge | 3–7 days | 1 day to 3 weeks | HSV-1 and HSV-2 are implicated in orofacial and genital primary infections |
| Other viral infections | ||||
| Viral meningitis | Inflammation in the lining of spinal cord and brain, headache, stiff neck, and fever | 3–7 days | 10 days | The most common cause of viral meningitis is echovirus or coxsackie groups of enteroviruses |
| Epstein–Barr virus (EBV) | Swollen lymph nodes, fatigue, fever, and enlarged spleen | 1–2 months | 4–6 weeks | EBV is a human herpes virus causing acute infectious mononucleosis and related to autoimmune disease and cancer |
| West Nile virus | Encephalitis or inflammation of surrounding tissues spinal cord and brain (meningitis) | 2–6 days | 2–14 days | Transmission is mainly through infected mosquitoes |