Viral Infections
Info History/RF Examination Investigation Management
HIV/AIDS Ax – Stages – Bedside – BSL, pharyngeal Ongoing disease – HAART
HIV – human Transmission – serous fluids, sexual, Primary infection – acute retroviral syndrome swab, sputum testing (Highly active anti-
immunodeficiency paraenteral, needles, vertical retroviral therapy)
virus Stage 1 – slow decline in CD4 count; viral set point after Bloods – Will reduce viral load,
HIV 1 – Global 3mo; latent stage (no Sx); lasts 1-15 yrs; may have FBE, CRP, ESR, UEC, LFT increase CD4 count, reduce
pandemic/US, Epi – 1.7 million people infected in 2018, generalized lymphadenopathy Serum CD4 count – staging transmission, improve QoL
more common AID develops 10-15 yrs after HIV infection Stage 2 – slow declined in CD4 count, slight immune and progression of the Triple therapy – combo of
HIV 2 – restricted suppression; some more frequent infections – mouth disease anti-retroviral therapy –
to West Africa ulcers, recurring URTI, influenza, dermatitis; around 2 yrs Viral RNA load – infectious a NRTIs, NNRTIs, protease
Prevention – usually person is inhibitors
AIDS – acquired Screening blood products Stage 3 – CD4 count in 300s; constitutional Sx – Can get viral load to 0 – no
immune deficiency Safe needle usage infections, LOW, fever, diarrhoea, oral infections, deVere Imaging – longer transmissible
syndrome Barrier protection – condoms bacterial infections, dental issues, anaemia, around 2 yrs CXR
End stage of HIV RF prevention Stage 4 - <200 CD4 count +/- presence of AIDS defining Specialist referral
Defined by a series illnesses Dx Test Need thorough regular
of infections and Pre-exposure prophylaxis (PREP) HIV wasting syndrome – LOW >10% + chronic diarrhoea Rapid HIV test – screening follow up
malignancies = Give to high risk of being exposed – or fever >1 mo test (within first 3 weeks of Social and peer support
AIDS defining partners of someone with HIV, sex Pneumocystis jirovecii pneumonia (PJP) exposure, if ELISA not
illnesses worker, IVDU, no barrier protection >2 severe LRTI per year possible,, confirm w/ ELISA at Acute exposure – note the
CD4 T cell count Daily anti-virals – tenofovir and Oesophageal candidiasis 3mo) details of the person they
<200micrometres/L emtricitabine Secondary or military TB ELISA test – identify presence received it from – stage,
ADR – N/V, diarrhoea, headache Kaposi’s sarcoma of antibody; false -ive within CD4, viral load
CMV 3mo of infection, antibodies
Cryptococcal infections have not developed yet; PEP – Post exposure
Pathophys – HIV targets CD4 cells
HIV encephalopathy ALWAYS repeated at 3mo prophylaxis
(macrophages, dendritic cells, Th cells)
Cryptosporidium Serum western blot – best, Given to definite exposure
Non-Hodgkin lymphoma but $$$ to someone with
Invasive cervical Ca confirmed HIV
Within 72 hrs begin; 28 day
RF – IVDU, MWHSWM, sexual Hx – girls, guys, both, course of 3 anti-retrovirals
vaginal, oral, anal, insertive, receptive, barrier protection ADR – gut issues
EBV Ax – EBV (knowns as HHV-4); Generalised Lymphadenopathy – Bedside – Conservative
transmission – highly contagious and fatigue/malaise mobile, usually posterior Throat swab – rule out strep Fluid
Primary infection – spreads via bodily secretions, esp saliva cervical throat Rest
asymptomatic Pathophys – Tonsilitis or pharyngitis, Splenomegaly Analgesia – Panadol &
Symptomatic EBV infects B cells and epithelial cells in exudative pharyngitis, Hepatomegaly Bloods – nurofen
infection – tonsils → primary infection severe, for 3-5 days Leukoplakia – white FBE – presence of 50%
infectious (asymptomatic) Fever – mild, lasting 2 patches or spots (lesions) lymphocytes with at least Avoid contact sport – risk
mononucleosis Incubation period 2-6 weeks – EBV weeks form inside the mouth 10% atypical lymphocytes of splenic rupture
(AKA glandular replicates in B cells → virus shed into Other – headache, abdo (resemble monocytes) Avoid amoxycillin – itchy
, fever) saliva pain, N/V LFTs macropapular rash in up to
EBV induces immune response → B cells IgG, IgM, EBV antibody titre 90% of people
mounts immune response locally (tonsils) Serology
or in other places (lymph nodes, spleen, Blood film – possible red cell
liver)- symptomatic agglutination
B cells stimulate CD8 T cell activity; B cells
also activated → plasma cells → Special tests
produced antibodies against EBV Monospot – rapid, specific,
B cells stimulate CD8 T cell activity; B cells but not sensitive; presence of
also activated → plasma cells → heterophile antibodies
produced antibodies against EBV produced by infected B cells
Cx – splenomegaly (splenic rupture),
hepatomegaly (hepatitis), rash due to
amoxycillin, post-infective chronic fatigue
syndrome, encephalitis, B-, T and NK-cell
derived Ca e.g Burkitt’s lymphoma,
airway compromise due to large tonsils
Influenza Ax – class of orthomoxyvirus (spherical Viral URTI – headache, myalgia, fever, sweats, rigors, Nasopharyngeal swab + PCR Symptomatic – rest,
Characterised by RNA virus); Influenza A – large pandemics sore throat, cough, nasal congestion Serology hydration, analgesia
upper and lower due to antigenic shift/drift; influenza B – Sick contacts High risk – can give anti-
respiratory tract Sx smaller outbreaks i.e epidemics due to Vaccinations Clinical Dx virals – oseltamivir
Usually in winter antigenic drift i.e point mutations in H Smoking Start within 48 hrs of Sx,
season and N enzymes; Influenza C – rare variant Underlying resp pathology – CF, bronchiectasis, reduces Sx by 1-2 days
Transmission – directly via respiratory immunosuppression – corticosteroids, chemo
droplets (sneezing or coughing) or Recent travel Prevention – hygiene,
indirectly through contact with seasonal vaccination – esp
contaminated surfaces if at high-risk e.g young
kids, elderly, comorbid
Incubation period – 2-3 days illnesses
Oseltamivir can be used
prophylactically for high
risk
Stay at home if sick
Dengue Ax – dengue virus (serotype – DENV 1-4); High fever Bedside – Assess severity and
Viral disease RNA virus of the genus flavivirus Headache Bloods – therefore admission
transmitted by Transmission – vector-borne – Body aches – arthralgia, myalgia FBE – Hct elevated, Fluid resus (+/- blood
Info History/RF Examination Investigation Management
HIV/AIDS Ax – Stages – Bedside – BSL, pharyngeal Ongoing disease – HAART
HIV – human Transmission – serous fluids, sexual, Primary infection – acute retroviral syndrome swab, sputum testing (Highly active anti-
immunodeficiency paraenteral, needles, vertical retroviral therapy)
virus Stage 1 – slow decline in CD4 count; viral set point after Bloods – Will reduce viral load,
HIV 1 – Global 3mo; latent stage (no Sx); lasts 1-15 yrs; may have FBE, CRP, ESR, UEC, LFT increase CD4 count, reduce
pandemic/US, Epi – 1.7 million people infected in 2018, generalized lymphadenopathy Serum CD4 count – staging transmission, improve QoL
more common AID develops 10-15 yrs after HIV infection Stage 2 – slow declined in CD4 count, slight immune and progression of the Triple therapy – combo of
HIV 2 – restricted suppression; some more frequent infections – mouth disease anti-retroviral therapy –
to West Africa ulcers, recurring URTI, influenza, dermatitis; around 2 yrs Viral RNA load – infectious a NRTIs, NNRTIs, protease
Prevention – usually person is inhibitors
AIDS – acquired Screening blood products Stage 3 – CD4 count in 300s; constitutional Sx – Can get viral load to 0 – no
immune deficiency Safe needle usage infections, LOW, fever, diarrhoea, oral infections, deVere Imaging – longer transmissible
syndrome Barrier protection – condoms bacterial infections, dental issues, anaemia, around 2 yrs CXR
End stage of HIV RF prevention Stage 4 - <200 CD4 count +/- presence of AIDS defining Specialist referral
Defined by a series illnesses Dx Test Need thorough regular
of infections and Pre-exposure prophylaxis (PREP) HIV wasting syndrome – LOW >10% + chronic diarrhoea Rapid HIV test – screening follow up
malignancies = Give to high risk of being exposed – or fever >1 mo test (within first 3 weeks of Social and peer support
AIDS defining partners of someone with HIV, sex Pneumocystis jirovecii pneumonia (PJP) exposure, if ELISA not
illnesses worker, IVDU, no barrier protection >2 severe LRTI per year possible,, confirm w/ ELISA at Acute exposure – note the
CD4 T cell count Daily anti-virals – tenofovir and Oesophageal candidiasis 3mo) details of the person they
<200micrometres/L emtricitabine Secondary or military TB ELISA test – identify presence received it from – stage,
ADR – N/V, diarrhoea, headache Kaposi’s sarcoma of antibody; false -ive within CD4, viral load
CMV 3mo of infection, antibodies
Cryptococcal infections have not developed yet; PEP – Post exposure
Pathophys – HIV targets CD4 cells
HIV encephalopathy ALWAYS repeated at 3mo prophylaxis
(macrophages, dendritic cells, Th cells)
Cryptosporidium Serum western blot – best, Given to definite exposure
Non-Hodgkin lymphoma but $$$ to someone with
Invasive cervical Ca confirmed HIV
Within 72 hrs begin; 28 day
RF – IVDU, MWHSWM, sexual Hx – girls, guys, both, course of 3 anti-retrovirals
vaginal, oral, anal, insertive, receptive, barrier protection ADR – gut issues
EBV Ax – EBV (knowns as HHV-4); Generalised Lymphadenopathy – Bedside – Conservative
transmission – highly contagious and fatigue/malaise mobile, usually posterior Throat swab – rule out strep Fluid
Primary infection – spreads via bodily secretions, esp saliva cervical throat Rest
asymptomatic Pathophys – Tonsilitis or pharyngitis, Splenomegaly Analgesia – Panadol &
Symptomatic EBV infects B cells and epithelial cells in exudative pharyngitis, Hepatomegaly Bloods – nurofen
infection – tonsils → primary infection severe, for 3-5 days Leukoplakia – white FBE – presence of 50%
infectious (asymptomatic) Fever – mild, lasting 2 patches or spots (lesions) lymphocytes with at least Avoid contact sport – risk
mononucleosis Incubation period 2-6 weeks – EBV weeks form inside the mouth 10% atypical lymphocytes of splenic rupture
(AKA glandular replicates in B cells → virus shed into Other – headache, abdo (resemble monocytes) Avoid amoxycillin – itchy
, fever) saliva pain, N/V LFTs macropapular rash in up to
EBV induces immune response → B cells IgG, IgM, EBV antibody titre 90% of people
mounts immune response locally (tonsils) Serology
or in other places (lymph nodes, spleen, Blood film – possible red cell
liver)- symptomatic agglutination
B cells stimulate CD8 T cell activity; B cells
also activated → plasma cells → Special tests
produced antibodies against EBV Monospot – rapid, specific,
B cells stimulate CD8 T cell activity; B cells but not sensitive; presence of
also activated → plasma cells → heterophile antibodies
produced antibodies against EBV produced by infected B cells
Cx – splenomegaly (splenic rupture),
hepatomegaly (hepatitis), rash due to
amoxycillin, post-infective chronic fatigue
syndrome, encephalitis, B-, T and NK-cell
derived Ca e.g Burkitt’s lymphoma,
airway compromise due to large tonsils
Influenza Ax – class of orthomoxyvirus (spherical Viral URTI – headache, myalgia, fever, sweats, rigors, Nasopharyngeal swab + PCR Symptomatic – rest,
Characterised by RNA virus); Influenza A – large pandemics sore throat, cough, nasal congestion Serology hydration, analgesia
upper and lower due to antigenic shift/drift; influenza B – Sick contacts High risk – can give anti-
respiratory tract Sx smaller outbreaks i.e epidemics due to Vaccinations Clinical Dx virals – oseltamivir
Usually in winter antigenic drift i.e point mutations in H Smoking Start within 48 hrs of Sx,
season and N enzymes; Influenza C – rare variant Underlying resp pathology – CF, bronchiectasis, reduces Sx by 1-2 days
Transmission – directly via respiratory immunosuppression – corticosteroids, chemo
droplets (sneezing or coughing) or Recent travel Prevention – hygiene,
indirectly through contact with seasonal vaccination – esp
contaminated surfaces if at high-risk e.g young
kids, elderly, comorbid
Incubation period – 2-3 days illnesses
Oseltamivir can be used
prophylactically for high
risk
Stay at home if sick
Dengue Ax – dengue virus (serotype – DENV 1-4); High fever Bedside – Assess severity and
Viral disease RNA virus of the genus flavivirus Headache Bloods – therefore admission
transmitted by Transmission – vector-borne – Body aches – arthralgia, myalgia FBE – Hct elevated, Fluid resus (+/- blood
