HIV Infection and AIDS

– AIDS (acquired immunodeficiency syndrome) is the most severe form of HIV infection (HIV).

– There are two serotypes. HIV-1 is the most common. HIV-2 is found mainly in

West Africa. Its virulence and its transmission are lower than those of HIV-1.

– HIV affects the immune system and leads to a deficit of CD4 lymphocytes.

Course of infection:

– Primary infection or acute retroviral syndrome: 50 to 70% of newly infected people develop at the time of seroconversion, a viral syndrome with fever, malaise, lymphadenopathy (15 days to 3 months after exposure).

– Asymptomatic infection with HIV (after seroconversion): a period characterized by a clinical latency without viral latency. The median period before the onset of AIDS is 10 years in Western countries, it seems shorter in developing countries.

– Symptomatic HIV Infection: with the progressive destruction of immunity, common or severe diseases occur more frequently with higher mortality, in HIV patients.

– AIDS: this stage corresponds to the onset of severe opportunistic infections and

neoplasia. From a biological perspective, AIDS is defined by a CD4 count <200 / mm3. Without treatment, the disease progresses rapidly to death.

WHO clinical staging of HIV / AIDS (in adults and adolescents with HIV infection confirmed):

WHO has proposed a clinical classification of HIV infection in 4 stages of increasing severity:

Clinical Stage 1:

asymptomatic patient

Persistent generalized lymphadenopathy

Clinical Stage 2:

Unexplained moderate weight loss (<10% of presumed or measured body weight)

recurrent respiratory tract infections (sinusitis, tonsillitis, otitis media, pharyngitis)

Herpes zoster

Angular cheilitis (angular cheilitis)

Ulceration chronic mouth

Papular pruritic eruptions

seborrheic dermatitis

fungal nail infections

Clinical Stage 3:

unexplained significant weight loss (> 10% of presumed or measured body weight)

Unexplained chronic diarrhea for more than a month

Unexplained persistent fever (temperature above 37.5 ° C intermittent or constant for more than a month)

Persistent oral candidiasis

Oral hairy leukoplakia

Pulmonary tuberculosis

severe bacterial infections (pneumonia, empyema, Pyomyositis, bone or joint infection, meningitis, septicemia)

Necrotizing ulcerative stomatitis and acute, gingivitis or periodontitis

Anemia (<8 g / dl), neutropenia (<0.5 x 109 / l) and / or chronic thrombocytopenia (<50 x 109 / l3) unexplained

Clinical stage 4:

cachectisant Syndrome HIV

Pneumocystis

Recurrent severe bacterial pneumonia

Chronic infection with Herpes simplex (orolabial, genital or anorectal of more than a month or visceral at any site)

Esophageal candidiasis (or trachea, bronchus or lung)

extrapulmonary tuberculosis

Cytomegalovirus infection (retinitis or infection of other organs)

Toxoplasmosis of the central nervous system

Encephalopathy due to HIV

Extrapulmonary cryptococcosis (including meningitis)

nontuberculous mycobacterial infection spread

progressive multifocal leukoencephalopathy

chronic cryptosporidiosis

chronic isosporiasis

Disseminated mycosis (extrapulmonary histoplasmosis, coccidioidomycosis)

Recurrent septicemia (including sepsis Salmonella non-typhi)

Lymphoma (cerebral or B-cell non-Hodgkin)

invasive cervical carcinoma

Atypical disseminated leishmaniasis

Nephropathy or symptomatic cardiomyopathy related to HIV

Note: This classification applies only to adults and adolescents. Another classification into four stages is used for the child.

Laboratory:

Diagnosis of HIV infection:

– The diagnosis is performed using serological tests.

– The tests must be performed with the informed consent of a voluntary patient.

No screening can not be mandatory. Everyone has the right to know or ignore their status. Test results are confidentialto avoid discrimination. The person must have access to minimum services offering advice (before and after the test), treatment and support.

– The diagnosis is positive when at least 2 different tests (2 different brands) are clearly positive.

– A first negative test should best be renewed three months later to exclude seroconversion (window).

CD4 count:

– The CD4 lymphopenia is a marker for the progression of immunodeficiency. She predicts the occurrence of opportunistic infections or malignancies and guide their diagnosis (eg cerebral toxoplasmosis or cryptococcal meningitis appear when the CD4 count is 100 sq / mm3. If clinical signs are évoquateurs but that CD4 is ³ 200 / mm3, it is unlikely that these infections are actually present).

– CD4 count can also ask the indications for primary prophylaxis and ARV.

Treatment of HIV infection:

Treatment with antiretroviral (ARV):

HAART (at least 3 ARV) is the standard treatment. It does not cure the virus but can delay the progression of the disease and improve the patient’s clinical status, reducing viral replication and raising CD4 counts above the threshold of appearance of opportunistic infections.

Therapeutic classes:

There are 3 major classes of ARVs:

– NRTI (nucleoside / nucleotide reverse transcriptase inhibitors): zidovudine (AZT), lamivudine (3TC), didanosine (ddI), stavudine (d4T), abacavir (ABC), tenofovir (TDF), emtricitabine (FTC).

– NNRTI (non-nucleoside reverse transcriptase): efavirenz (EFV), nevirapine (NVP). HIV-2 is naturally resistant to NNRTIs.

– IP (PIs) indinavir (IDV), lopinavir (LPV), ritonavir (RTV), saquinavir (SQV).

Principles of treatment:

– A life daily treatment with triple therapy is needed to prevent the rapid development of resistance. It is essential that the patient has understood and that adherence to treatment is optimal.

– The most conventional associations and simpler administration are 2 NRTI + 1 NNRTI: p. ex. d4T + 3TC associated with NVP or EFV (EFV is against-indicated in pregnant women).

– If unsuccessful, use the second line 2 NRTIs + 1 PI.

There are other possible combinations, less commonly used, or difficult to manage.

Criteria for ARV treatment:

When the number of patients eligible for treatment is high, it seems legitimate to begin treating patients already in clinical stages 3 and 4 and the most patients at risk for severe opportunistic infections, that is to say who a CD4 count <200 / mm3.

Surveillance:

CD4 is useful to initiate and monitor the treatment. NFS, hemoglobin and ALT are not indispensable but may be useful for the detection of side effects. Viral load (rarely available) is used for the detection of failures.

Treatment of opportunistic infections and other infections:

Due to the progressive destruction of immunity, patients who do not receive HAART (or whose adhesion is random) become more and more vulnerable to infection. Conventional treatments are usually effective for diseases of the clinical stages 2 and 3 and the diagnosis of HIV infection alters little support. Once these stages, patients may benefit from primary prophylaxis.

Severe opportunistic infections often require diagnostic and therapeutic means more sophisticated, rarely available.However, with improving health structures, most of these diseases can be treated.

For the treatment of opportunistic infections.

Pain Treatment:

In any case, do not overlook the management of associated pain.

Prevention of HIV infection:

– Sexual Transmission:

The use of male or female condoms is the only reliable prevention.

On the other hand, STDs promoting HIV transmission, it is essential to detect and treat early.

PEP: in cases of rape, for example, ARV treatment started within 48 hours for a period of one month may reduce the risk of transmission.

– Blood Transmission:

• transfusion: strict compliance with indications transfusion and systematic serological screening of donor blood are the two essential precautions to safe blood.

• drug IV needle exchange program for single use among users.

– Exposure to blood accidents during care proceedings (puncture or wound with a contaminated object, contact between the blood of a patient and the injured or unprotected skin mucous membranes)

Prevention is based on universal precautions to avoid contamination with soiled equipment or potentially infected body fluids.

PEP: Accident, ARV treatment started within 48 hours for a period of one month reduces the risk of transmission.

– Nosocomial:

Prevention of nosocomial HIV infection is based on the rational use of injections and strict respect of hygiene procedures, sterilization and disinfection of medical equipment.

– Mother to child transmission (MTCT):

The overall transmission ratio varies from 20 to 40%. The risk from breastfeeding is evaluated at about 12% and persists for the duration of breastfeeding.

In pregnant women: HIV transmission from mother to child can be reduced by ARVs. Several protocols complexity, duration and effectiveness of different exist. The most commonly used ARV are AZT, 3TC, NVP. They are administered to the mother during pregnancy, childbirth, postpartum and newborn.

Inform national protocols.

Programs for pregnant women have other preventive measures: no routine episiotomy; avoid artificial rupture of membranes. In certain situations and if the context permits, the planned caesarean section (before the start of labor and before the rupture of membranes), under cover of antiretroviral therapy, can reduce the maternal-fetal transmission. However, it is imperative to assess the risk-benefit of cesarean section.

In lactating women: artificial feeding if the milk supply and drinking water is guaranteed. Otherwise, continue exclusive breastfeeding until the age of 6 months, then rapid withdrawal. Mixed feeding (maternal + artificial) is cons-indicated.

Prevention of opportunistic infections:

Without ARVs, any HIV infection becomes symptomatic and progresses to AIDS. Some of these infections are preventable.

Primary prophylaxis:

To avoid the appearance of opportunistic infections in patients infected with HIV.

Criteria for primary prophylaxis:

– In the absence of CD4 count: WHO clinical stages 2, 3 and 4.

– If the CD4 count is possible: WHO clinical stages 3 and 4 regardless of CD4 count and WHO clinical stages 1 and 2 if CD4 <350 / mm3 (or 500 / mm3, according to national guidelines).