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• Mycoplasma pneumonia – mycoplasma are the smallest free living organisms. They are a pleomorphic organism.

  They are prokaryotes – lack cell wall. No reaction to gram stain. They are found in the uriogenital and respiratory tracts.

  Species are mycoplasma pneumonia, genitalium, hominis and ureaplasma species.
• Mycoplasma Pneumonia epidemiology – spread through respiratory droplets from close contact.

  During winter and fall infection usually occurs.

  Pathogenesis – it is a superantigen.

  Activates lymphocytes and macrophages and stimulates cytokine production

  Induces cytokine secretion and attract inflammatory cells

  Incubation period is 3 weeks

  Host factors contribute to pathogenesis.
• Streptococcus pneumoniae – it is gram positive and arranged in pairs.

  The surface capsule is the distinguishing trait of the pneumococcus and is the major virulent factor
• Streptococcus pneumonia – it is found in people under 2 years old and over 60. it can infect animals and humans. Transmission is through respiratory droplets and oral contact. Transmission is common but infections is not so healthy people may carry the disease but not have symptoms. Incubation period is 1-3 days.
• Treponema pallidum – are wide coiled spirochetes.

  They have a periplasmic flagella covering, peptidoglycan cytoplasmic membrane complex and a protoplasmic cylinder.

  Reproduce through transverse binary fission. They cannot survive outside body and can easily be killed by chemical and physical element.
• Treponemes pathogenesis – invasive pathogens that quickly spread after infection. They can evade immune system due to the lack of surface proteins on their membrane. They have lipoproteins to trigger inflammation.
• Treponema epidemiology – humans are the only host. Transmission is through direct contact of mucous membrane through sexual activity. Venereal syphilis – 4 stages (primary – individual sores around genitals), (secondary – widespread rash around hands and feet), (latent – active bacteria but asymptomatic) and (teritary – leads to death due to skeletal, nervous, circulatory and vital organ damage)

  Congenital syphilis is from infected mother to child through bloodstream. Usually when mother is at the secondary to latent stage. 
• Candida albicans – its an oval budding yeast. It is found in the GI and genitourinary tract. Candida can appear in immunocompromised and chemotherapy patients, low weight babies, organ recipients.

  There are 3 main candida diseases – oropharyngeal candidiasis (thrush), vulvovaginal candidiasis (yeast infections) and Invasive candidiasis (serious infection to parts of the body)
• Thrush can be caused due to the low immune system, vertical transmission and it is a common cause of vaginitis
• Candida epidemiology – top source of fungal infections in immunocompromised people.
• Candida transmission – usually through infected mother to infant through childbirth. Overgrowth leads to disease when there are imbalances in the body.

  These infections can also happens in hospitals (HAI) where immunocompromised patients acquire yeast infection from healthcare workers.
• Kaposi sarcoma – rare tumor. It is caused by herpes virus. Found in immunocompromised or HIV people. HIV people have this sarcoma and therefore diagnosed with AIDS.
• KS is a vascular tumor that affects soft tissues in multiple areas. Originates from blood vessel endothelial cells.

  There are 4 main types of kaposi sarcoma – Classic (rare tumor affecting older males), Epidemic (common form and is known as AIDS associated), Endemic (african sarcoma and affect children and adults independent of HIV infection) and Iatrogenic (known as immunosupressive-treatment related KS)
• KS - Human herpes virus 8 has many transmission modes. Can be spread non-sexually and sexually. More likely in people with HIV.

  Can be seen as skin marks that are asymptomatic, red blemishes, oedma and can merge into plaques and nodules.
• Transmission – kaposi sarcoma are in people with low CD4 count and immunocompromised individuals.

  The herpesvirus 8 is more common in equatorial africa.
• Cervical carcinoma – cancer of cervix. It is like an STD. strains (HPV) only affect epithelial cells like skin, anogenital mucossa and oropharyngeal mucosa.
• Non-Hodgkins lymphoma – cancer of lymphatic system that can spread throughout the body. AIDS related lyphoma are in people with AIDS and it can also spread rapidly. Tumors form from lymphocytes. More common than hodgkins lymphoma.
• Causes of non hodgkins lymphoma – they can either be slow growing or fast growing. AIDS related lymphoma tends to be aggressive. Lymphocytes don’t die and keep growing and dividing in non hodgkins lymphoma. Overgrowth leads to swollen lymph nodes.
• Non hodgkins lymphoma can happen in the B and T cells.

  B cells – most of the non-hodgkins lymphoma arises from the B cells (produces antibodies).

  T cells – non-hodgkins lymphoma occurs less from these cells.
• Factors that increase Non hodgkins lymphoma are – immunosupressive medications, viral/bacterial infections, chemicals (insecticides) and aging.
• Symptoms of Non-hodgkins lymphoma – painless, fatigue, fever, weight loss, night sweats and abdominal pain and swelling.