Acute meningoencephalitis and meningitis due to primary HIV infection

A wide differential diagnosis exists for meningoencephalitis and meningitis: causes include tuberculosis and infections caused by viruses such as enteroviruses, human herpesviruses (types 1-4, 5 (cytomegalovirus), and 6), paramyxovirus (mumps), measles virus, and adenoviruses. In one cohort, viral genomes were detected in consecutive samples of cerebrospinal fluid from 5% of patients (22 of 410); enteroviruses and human herpesviruses types 1-5 accounted for over 95% of cases.1 HIV infection was not detected. It is often overlooked as a potential cause of meningoencephalitis and meningitis.

The clinical manifestations of primary HIV infection are well characterised and include fever, lethargy, flu-like illness, headache, pharyngitis, generalised rash, lymphadenopathy, and gastrointestinal disturbances.2 Neurological features, including aseptic meningitis, meningoencephalitis, and encephalitis, occur in up to 17% of patients and may be associated with more rapid progression of HIV related disease.3^–11 Neurological symptoms may occur or develop up to 3 months after the onset of symptoms of primary HIV infection, when the other symptoms have resolved. We discuss one patient with meningoencephalitis and two patients with meningitis associated with primary HIV infection. In each patient the underlying diagnosis of primary HIV infection was not suspected initially resulting in a delay to diagnosis.

Commentary: Is testing for HIV without consent justifiable?

Ethical guidance insists that people should normally be tested for HIV only with valid consent because although it is potentially beneficial medically, the social and psychological implications can be serious. This emphasis on voluntariness of testing remains strong even as the success of antiretroviral treatment increasingly highlights the benefits of early diagnosis. For most people those benefits are an overriding consideration. It can be argued, therefore, that most patients who know themselves to be at risk would be likely to accept HIV testing to ensure that they obtain optimal treatment. Nevertheless, there may be some patients for whom uncertainty about their status is preferable. If, when able to make a choice, they elect to avoid testing and take the risks associated with not knowing, that decision must be respected. They cannot normally be tested without their agreement. A third category of people lack information about risk factors and warning signs. Since it probably does not occur to them to ask for a test or to talk to doctors about their private activities, they are dependent on health professionals to pick up potential symptoms. That is why Newton et al's article is so important for raising medical awareness but, by implication, it also raises questions about second guessing patients' views.

Problems arise when patients are mentally ill, unconscious, or otherwise so incapacitated that they cannot consent or refuse. Doctors are legally and ethically obliged to act in such patients' “best interests,” which include, but are not restricted to, their clinical interests. Assessing best interests involves forming a view about a patient's likely preferences: a virtually impossible thing to do if there is no clue about whether they positively opposed testing or simply had never considered it. It is a harm to impose an intervention that patients have positively rejected but a benefit to provide one that they would want if they had knowledge of it. In other contexts, families can indicate what the patient wanted, but raising the spectre of HIV with partners or relatives is obviously problematic when nothing in the patient's record indicates that this is an appropriate question.

In the absence of evidence to the contrary, logic dictates that most people would want interventions that could save them. The General Medical Council acknowledges that unconscious patients can be tested where that would be in their immediate clinical interests for the purpose of making a diagnosis.1 In urgent cases, therefore, where knowledge of the patient's HIV status would seriously affect treatment, it can be permissible to test without consent. If, however, appropriate prophylactic treatment could usefully be provided without obtaining a definitive diagnosis or if treatment options would be much the same regardless of HIV status, testing without consent is less likely to be justified. This is because legal and ethical guidance stresses the importance of taking the least invasive effective option when treating people with impaired capacity. If the incapacity is temporary, doctors are expected to wait for the patient to revive before making any life changing decisions or going beyond what is immediately essential. Obviously this raises questions about how to define “essential” and its limits.

The authors draw attention to the importance of considering HIV infection as a potential cause of neurological conditions. Failure to test for primary HIV infection might result in crucial delays in antiretroviral therapy or leave patients open to infection when immunosuppressed. But in case 1, testing when the patient was presumably too ill to consent seems to have had no impact on his actual treatment. He was given antivirals as a precaution but had improved by the time the diagnosis was known and so antiretroviral therapy was unnecessary. Although the action taken was reasonable, with hindsight it can be seen that treatment was not contingent upon a definite diagnosis and testing might have waited. In other—and perhaps most—cases, testing promptly without consent could save lives. Thus, as well as the important clinical message, the paper highlights the complex dilemmas that doctors increasingly face. Despite the generally positive approach among health professionals to early HIV testing, there still needs to be much more public awareness of it as an option so that patients who could benefit from prompt testing seek it and those who genuinely object can take steps to make those views known.