INFECTIOUS DISEASES

Emerging infectious diseases

- Diseases of infectious origin with human incidences that have increased within the past two decades or that are likely to increase in the future

A. West Nile virus- emerging pathogens in humans caused by flavivirus- Most human infections are asymptomatic, when sx are present headache and fever are most frequently

reported- Incubation period: 5-15days- No treatment- Transmission: birds are the natural reservoir for the virus- Bite of infected mosquito that has fed on infected bird- Not transmitted person to person- Aedes albopictus- Implication for nursing: teach prevention of mosquito bites by wearing proper clothing and using insect

repellent- Teach people in affected areas to wear gloves in handling dead birds

B. Legionnaire’s disease- caused by gram-negative bacteria, Legionella pneumophila- Legionella organisms are found in many man-made and naturally occurring water sources- Transmission: aerosolized route from an environmental source to an individual’s respiratory tract- Risk factors: dses that lead to severe immunosuppression such as AIDS, hematologic malignancy, end-stage renal

disease, use of immunosuppressive agents (steriods)- CxMx: early sx: malaise, myalgias, headache, dry cough; inc pulmonary sx, productive cough, dyspnea, chest

pain, usually frebile may reach 39.4C or higher)- Med mgt: Azithromycin (Zithromax), Clarithromycin, Erythromycin, Levofloxacin- Nsg mgt: described for the pt with any pneumonia- Isolation not necessary

C. Lyme Disease- Borrelia burgdorferi- Transmittted to humans by ticks- Ticks may feed on infected white-tailed deer or white-footed mice which serve as a vector to transmit to humans- CxMx: erythema migrans is the best clinical marker, flu-like sx, inflamed painful arthritis, limb weakness; in later

stage, neurologic manifestations from mild Bell’s palsy to GBS (Guillaine Barre’s Syndrome) (paralysis) or dementia

- Nsg con: not communicable from person-persono Best means of prevention is the avoidance of tick-infested areaso Ticks should be removed with tweezers or forceps to avoid leaving mouth parts in the skin: pull upwardo Insect repellant

D. Hantavirus pulmonary syndrome (Hps)- Caused by a member of hantavirus family of viruses- Infected rodents known to carry the virus are found worldwide- Thrombocytopenia and hemoconcentration are common- No specific tx has been approved- Transmission: believed to occur through aerosolization of rodent excreta- Nsg con: rodent control, proper storage of food, careful wet mop cleaning and disinfection of rodent-

contaminated areas.E. Ebola and Marburg Viruses

- Caused by filoviruses characterized by severe hemorrhagic fevers, often accompanied by hepatic and renal damage

- Mortality rate: marbug virus: 25%o Ebola: 50-90%

- Filoviruses: clincal course- often occur rapidlyo Fever, rash, encephalitiso Profound hemorrhage, organ destruction, shocko Mortality rate: 90%o Survivors: prolonged recovery period (weakness, malaise, cachexia common)

o Human-human transmission (blod or body fluid)o Percutaneous transmissiono Mucous membrane exposureo Possible airborne transmissiono Strict infection control measureso No antiviral tx approved yeto Supportive tx (MechVent, dialysis)o Contact CDC asap

F. Severe Acute Respiratory Syndrome (SARS)- Caused by member of coronavirus family- An influenza-like dse (s/sx: cough, fever)- Respiratory distress in minority of cases- Barrier precautions- Nsg con: measure body temp, ventilation, drink more water, wash hands frequently, wear gauze mask

G. AH1N1 virus (swine flu)- Is a combination of 4 viruses from swine, bird- First reported in the US in April of 2009- Transmitted from person-person, same with seasonal influenza virus- Caused by infection with a novel coronavirus- CxMx: similar sx with regular flu:

o Fever and headache, fatigue and muscle aches, loss of appetite, nasal congestion, sore throat and cough, others report of diarrhea and N/V

- Mode of transmission: exposed to persons who are sneezing and coughing and positive of the viruso Touching the mouth, nose, and eyes after contact with persons positive of the virus

- What to do?o Should wear surgical masko Separate room or if not, give 1 meter distance from each family membero Good ventilationo Handwashing after each contact with the patiento Environmental sanitation

- Prevention:o Hand washingo Avoid people who are positiveo Increase body’s resistance:

Inc fluid intake 8 hours of sleep

- Home based care: reducing risk to the patient:o Hand hygieneo Equipment careo Patient teaching

- Reducing risk to household members:o Establishing barrierso Food preparation

Dse Causative agents Mode of transmission

Clinical manifestations Treatment

WEST NILE VIRUS Birds: Flavivirus Mosquito: aedes albopictus

LEGIONNAIRE’S DSE Water resources: Legionella pneumophilia

Aerolized route malaise, myalgias, headache, dry cough; inc pulmonary sx, productive cough, dyspnea, chest pain, usually frebile may reach 39.4C or higher)

Azithromycin

LYME DSE White-tailed deer or white-footed mice: Borrelia burgdorferi

Ticks Erythema migrans, mild Bell’s palsy to GBS or dementia

Ticks removed with tweezers

HANTAVIRUS PULMONARY SYNDROME

Rodents: hantavirus

Aerolization of rodent excreta

Hemoconcentration, thrombocytopenia

Rodent control

EBOLA AND MARBURG Filoviruses Severe hemorrhagic fever, often accomp. By hepatic and renal failure

Contact CDC asap

SEVERE ACUTE RESPIRATORY SYNDROME

Coronavirus Flu-like sx Barrier protection

AH1N1 Swine, birds: coronavirus

Flu-like sx Barrier protection