Infectious Diseases Flashcards
What is the most severe and dangerous organism causing malaria?
Plasmodium falciparum
Name the other types of malaria
Plasmodium vivax
Plasmodium ovale
Plasmodium malariae
Protective factors for malaria
Sickle-cell trait
G6PD lack
Symptoms of Plasmodium falciparum
FEVER Sweats Rigors Malaise Myalgia Headache Vomiting
When should you suspect malaria in someone?
Someone who lives or has travelled to an area of malaria - AFRICA
Signs of Plasmodium falciparum
Anaemia
Jaundice - as bilirubin is released during RBC rupture
Hepatosplenomegaly
Complications of Plasmodium falciparum
Cerebral malaria Reduced consciousness/coma Seizures Acute kidney injury Disseminated intravascular coagulopathy (DIC) Severe haemolytic anaemia Pulmonary oedema/ARDs
Investigations for Plasmodium falciparum
Thick and thin blood films - 3 samples over 3 days FBC (anaemia/thrombocytopenia) Clotting (DIC) Glucose (hypoglycaemia) ABG/lactate (lactic acidosis) U&E (renal failure) Urinalysis (proteinuria, haemoglobinuria) Blood cultures
Treatment for uncomplicated falciparum malaria
Artemether-lumefantrine (Riamet)
Atovaquone-proguanil (Malarone)
Quinine sulphate
Doxycycline or clindamycin
Treatment for severe or complicated falciparum malaria
Artesunate IV
Quinine
Prophylaxis for malaria
Mosquito spray (DEET) Mosquito nets and barriers Wear long sleeves Antimalarials - doxycycline, mefloquine, malarone
Side effects of doxycycline?
Diarrhoea and thrush
Side effects of mefloquine
Insomnia
Seizures
Nausea
Side effects of malarone
Abdominal pain
Nausea
Headache
What is HIV?
A retrovirus that destroys CD4 T cells and is the cause of aids
How many types of HIV are there?
HIV 1 = global epidemic
HIV 2 = West Africa
How does HIV present?
The infection initially causes a seroconversion flu-like illness within a few weeks. Remains asymptomatic before the patient becomes immunocompromised and develops AIDS years later.
How is HIV transmitted
Unprotected anal, vaginal or oral sex
Vertical transmission: Mother -> Child
Sharing needles/IVDU
Blood transfusion
How does seroconversion/primary infection present?
Short-illness after infection, 2-6 weeks - highest infectivity Fever Malaise Blotchy red rash Aching limbs Headache Diarrhoea Mouth ulcers
How does the asymptomatic HIV infection present?
May last several years
Progressive loss of CD4 cells
30% have generalised lymphadenopathy - nodes >1cm at 2 extra-inguinal sites for 3 months or longer
How does symptomatic HIV infection present?
Pyrexia Night sweats Diarrhoea Weight loss Opportunistic infections - oral candida, oral hairy leukoplakia, herpes zoster, herpes simplex
How long does it take for HIV => AIDS?
5-10 Years
How long does it take for AIDS => Death (without HAART)?
2 Years
How is HIV diagnosed?
ELISA antibody blood test
PCR testing for HIV RNA/p24 antigen
CD4 count - these cells are destroyed by HIV virus; Normal = 500-,1200. <200 = end stage HIV/AIDS
Viral load - number of HIV RNA per ml of blood; uncontrolled = >500,000, well controlled = <40
What opportunistic infection can HIV present with?
TB Pneumonia Pneumocystis jiroveci pneumonia (PCP) - suspect if cough/breathlessness CMV M.avium intracellulare (MAI)/ MAC (complex) Candidiasis Toxoplasmosis Cryptococcal meningitis Herpes simplex virus Kaposi's sarcoma Burkitt's lymphoma CMV retinitis Oral hairy leukoplakia
What is the treatment for candidiasis?
Nystatin
If mucosal = Fluconazole
Treatment for toxoplasmosis?
Pyrimethamine + sulfadiazine + leucovorin
How does Pneumocystis jiroveci pneumonia (PCP) present?
Cough Breathlessness Fever Chest pain Fatigue
Investigations for Pneumocystis jiroveci pneumonia (PCP)
CT scan - diffuse ground glass opacity, consolidation, cysts, nodules
Induced sputum/bronchoalveolar lavage
Treatment for Pneumocystis jiroveci pneumonia (PCP)
High dose co-trimoxazole
Prophylaxis for HIV (recommended in all patients with CD4 <200)
Co-trimoxazole for PCP Cervical smears Vaccinations Azithromycin for MAI/MAC if CD4 <50 Isoniazid + Rifampicin for 3 months/ Isoniazid for 6 months Ganciclovir for treating CMV
Prevention for HIV
Blood screening PEP - pre and post exposure prophylaxis Condoms Circumcision Reduce vertical transmission
Treatment for HIV
HAART - highly active antiretroviral therapy
Use of at least three different antiretroviral drugs
Nucleoside reverse transcriptase inhibitors (NRTI)
Non-nucleoside reverse transcriptase inhibitors (NNRTI)
Protease inhibitors (PI)
Integrase inhibitors (II)
Examples of Nucleoside reverse transcriptase inhibitors (NRTI)
Zidovudine
Tenofovir
Lamivudine
Emtricitabine
Side effects of Nucleoside reverse transcriptase inhibitors (NRTI)
Anaemia Fever Rash GI disturbance Myalgia Decreased WCC
Examples of Non-nucleoside reverse transcriptase inhibitors (NNRTI)
Nevirapine
Efavirenz
Rilpivirine
Side effects of Non-nucleoside reverse transcriptase inhibitors (NNRTI)
Steven’s-Johnson syndrome/TEN
Hepatitis
Examples of protease inhibitors
Lopinavir
Ritonavir
Squinavir
Side effects of protease inhibitors
GI disturbance
Headache
Rash
Peripheral neuropathy
Examples of integrase inhibitors
Raltegravir
Elvitegravir
Dolutegravir
Side effects of integrase inhibitors
GI upset
Insomnia
What is post-exposure prophylaxis?
Used after exposure to HIV - commenced within 72 hours
4 week course of Tenofovir + emtricitabine + raltegravir
Define gastritis
Inflammation of the stomach
Nausea and vomiting
Define enteritis
Inflammation of the intestines
Diarrhoea
Define gastroenteritis
Inflammation from stomach -> intestines
Nausea and vomiting + diarrhoea
Causes of gastroenteritis
Contaminated food and water
Viral gastroenteritis
Bacterial gastroenteritis
Questions to ask when taking a gastroenteritis history
Food and water taken
Cooking methods
Others affected?
Causes of viral gastroenteritis
Rotavirus
Norovirus
Adenovirus
Symptoms of norovirus
Fever
Projectile vomiting
Symptoms of rotavirus
Diarrhoea
Vomiting
Fever
Malaise
Causes of bacterial gastroenteritis
E.coli Campylobacter Jejuni Shigella Salmonella Bacillus cereus Yersinia enterocolitica Staph aureus Giardiasis
How is e.coli spread?
Through infected faeces, unwashed salads or water