Abstract
The advantages of diagnosis of primary HIV infection (PHI) for the individual and public health are well documented. However, symptoms of HIV seroconversion are often not recognized by health-care professionals. Also, symptomatic patients themselves often do not present to health-care services. With the emergence of H1N1 infection, many patients with flu-like symptoms are seeking medical advice. Currently in the UK, the management of H1N1 is in the treatment phase, that is, patients are diagnosed and treated for H1N1 influenza based on clinical observation rather than laboratory testing. Symptoms of H1N1 infection are often similar to those of PHI. We present two cases of men who have sex with men from Brighton, UK presenting to general practice and accident and emergency with flu-like symptoms. Both were initially diagnosed on clinical grounds with H1N1 infection and treated empirically with antivirals but were later confirmed to, in fact, have symptomatic PHI. It is important in high-risk patients with flu symptoms attributed to swine flu infection, that PHI is also considered and excluded.
In July 2009 the UK moved to a treatment phase in the management of pandemic H1N1 (commonly known as swine flu), such that patients with specific symptoms were offered treatment empirically with antiviral medication. The present cases highlight the importance for health-care professionals to remember to consider primary HIV infection (PHI) as a cause of flu-like symptoms in patients from high-risk groups.
CASE REPORTS
A 41-year-old man who has sex with men (MSM) from Brighton, UK presented in July 2009 with symptoms of fever, headache, sore throat, joint and limb pains. He contacted his general practitioner (GP) who diagnosed swine flu on the basis of his symptoms and commenced him on oseltamivir (Tamiflu). He denied any contacts with known or suspected swine flu. A week later, he developed a maculopapular rash thought to be a reaction to Tamiflu. In the meantime, he had also self-referred to the genitourinary clinic where he had tests for HIV and syphilis. He had last tested HIV-negative six months previously. He denied any unprotected anal intercourse since his last test, but reported 30 casual male partners with whom he had engaged in unprotected receptive and insertive oral sex in the last three months. He had no other significant past medical or drug history.
On the same day, his anti-HIV 1 and anti-HIV 2 (GACPAT assay) were negative, but the fourth-generation HIV antigen/antibody tests (Integral and Abbott-M assays – OD/CO 2.3 using Abbott-M) were positive along with a positive p24 antigen (Biorad EIA). Syphilis, hepatitis B and C serology were negative. His HIV viral load was 1,866,699 copies/mL and CD4 lymphocyte count was 285 (27%) cells/mm3, CD4:CD8 ratio 0.66. The results were consistent with PHI.
A 43-year-old MSM from Brighton, UK also presented in July 2009 to his GP with a nine-day history of a rash affecting his neck and trunk, fevers and sweating. He experienced a vasovagal episode in clinic and was therefore referred to the emergency department. There, he was diagnosed with swine flu based on his symptoms, and commenced on a course of Tamiflu. He denied any contacts with swine flu and his last travel abroad was to Amsterdam five weeks previously. He re-presented to his GP as his symptoms were not improving, and he had developed a sore throat. He was referred to another emergency department where he was again given a diagnosis of swine flu. A dermatologist reviewed his rash and took a sexual history, which raised the concern of HIV seroconversion illness. His last negative HIV test was three months previously. He last had unprotected anal intercourse 12 days earlier with his regular male partner, and then eight weeks prior with a casual partner. He had no other past medical or drug history of note. On examination, he had palpable cervical lymphadenopathy, and a macular erythematous rash including some faint lesions on his palms and soles.
His anti-HIV 1 and anti-HIV 2 (GACPAT assay) were negative, but the fourth-generation HIV test showed a weakly positive result (OD/CO 14.2 using Abbott-M), and a positive p24 antigen response (Biorad EIA). His syphilis serology and hepatitis B and C antibody tests were negative. His HIV viral load was 22,054 copies/mL and CD4 369 cells/mm3 (26%), CD4:CD8 ratio 0.49.
DISCUSSION
It is highly advantageous both from an individual and public health perspective to diagnose PHI. 1,2 However, there are a significant number of missed opportunities to make the diagnosis in symptomatic patients seeking medical advice. 3 The diagnosis can be difficult as symptoms are non-specific in nature and self-limiting, usually resolving within two weeks. 4 In addition, up to half of symptomatic individuals do not even seek medical attention. 3
The influenza H1N1 pandemic has led to high rates of individuals presenting with flu-like symptoms. The most common symptoms include fever (94%), cough (92%) and sore throat (66%). 5 The criteria for diagnosis of H1N1 based on data from the Health Protection Agency UK are fever and two or more symptoms of cough, sore throat, rhinorrhoea, joint or limb pain, headache, vomiting or diarrhoea. 6,7 Symptoms of PHI include fever, sore throat, rash, headache, myalgia, diarrhoea and fatigue. 3,4 There have been very few cases of a rash associated with H1N1, and skin allergic reactions to oseltamivir are rare (<1%), so the presence of a rash should particularly alert the clinician to other diagnoses such as PHI or secondary syphilis. 6,8
In both cases, the vigilance by patients and health-care professionals to H1N1 eventually facilitated the diagnosis of PHI. Non-HIV/genitourinary (GU) medicine health-care providers, particularly those in primary care, may benefit from training to improve rates of diagnosis. 3 In the current pandemic, patients presenting with flu symptoms from high-risk groups should be offered an HIV test and referral to a GU clinic for follow-up including repeat HIV testing and screening for syphilis.