Information mostly taken from: "International Travel and Health" (WHO year book - internet only)
Australian Immunisation Handbook, 8th Edition - 9/2003 - Part1 - Part 2 & Part 3 (large pdf files)
Centre for Disease Control, USA -  www.cdc.gov/travel Travel Health Seminar Oct 96, June 97,Feb 98, March 99, May 2000, August 2002 & March 2005 - Victorian Medical Postgraduate Foundation.
Manual of Travel Medicine, Melbourne, Oct 2004. Updated 06/09/2006.  Additional references & disclaimer.

SAFE VACCINES

• Annual influenza vaccine is recommended for HIV-infected persons. Response rates to the vaccine exceed 80% in persons with asymptomatic HIV infection and are less than 50% in patients with AIDS.
• Immune globulin is safe.

UNSAFE VACCINES

• Oral polio vaccine (Sabin) is contraindicated in HIV-infected persons. For primary immunisation or booster immunisation against polio the inactivated polio vaccine should be used. OPV has not been proven to be harmful.

SPECIAL VACCINES WHICH MAY BE INDICATED

• Measles Yellow fever MMR

Yellow fever vaccine, a live viral vaccine, is not recommended for those with symptomatic HIV infection or CD4 counts of less than 200/cmm, because of the theoretical risk for vaccine strain encephalitis. Asymptomatic HIV-infected persons with CD4 cell count > 200 who must travel to areas where the risk of yellow fever is high should be vaccinated. Data from the US. military indicate that approximately 100 asymptomatic HIV-infected personnel received yellow fever vaccine before routine HIV screening: no adverse effects were detected. The vaccine should be given only for the traveller's protection. If the vaccine is required only for legal purposes, a letter of exemption from the doctor is generally acceptable.

Measles is endemic in devloping areas of the world. In HIV-infected persons, measles may be a devastating disease and is occasionally fatal. Persons may be considered to be immune to measles if they have a history of physician-diagnosed measles or protective levels of measles antibody. Measles outbreaks among previously vaccinated young adults indicate the occasional failutre of vaccine-induced immunity.

Although there is a risk for measles vaccine associated encephalopathy in immunosuppressed subjects, no severe complications occurred in more than 300 HIV-infected children immunised with this vaccine. One should weigh up the risks of contracting and developing severe measles disease against that of vaccine associated encephalopathy. Short term travellers not likely to have closed associated with the local population will have a low risk of exposure to measles. However if the contact is likely to be closed and prolonged the risk may be substantial and immunisation with the live vaccine would be justified.

Response rates of the vaccine among HIV-infected persons ranges from 50 to 58% in those with symptoms
The risk of exposure to mumps and rubella may also be increased during travel, the MMR (measles, mumps and rubella) vaccine should be considered.
MMR is recommended by US authorities as routine immunisation for asymptomatic HIV-infected children.
For symptomatic HIV-infected children the vaccine should also be considered.

NHMRC (1994) states "HIV-positive individuals may be given MMR vaccine in the absence of other contraindications", and "MMR should be routinely administered to HIV-infected children at 12 months of age".

CDC Recommendations for routine immunisation of HIV-infected children

* should be considered
MALARIA

• Studies have shown little, if any, increased morbidity from malaria in HIV-infected persons from malaria-endemic areas. Whether the morbidity of malaria is increased in HIV-infected travellers from outside malaria-endemic areas is unknown.
• Anti-mosquito measures are obviously important (see Malaria pamphlet). Chemoprophylaxis (taking drugs to prevent malaria) is essential.
• Chloroquine is acceptable. Because its is immunosuppressive, theoretically it could affect host response to infections or could contribute to progression of HlV-related disease. There are no clinical data on this issue.
• Proguanil is acceptable. Data is limited.
• Maloprim is no longer recommended as a prophylactic drug for malaria.
• Doxycycline is acceptable.
• Mefloquine is acceptable, but there is limited data.

TRAVELLER S DIARRHOEA
(See the pamphlet on Traveller's Diarrhoea.)

• The principal risk for the HIV-infected traveller is enterically acquired infections. Several of the pathogens causing traveller's diarrhoea cause disease in HIV-infected person that is severe, recurrent or persistent, and associated with extraintestinal spread.
• Gastric acid secretory failure is common in patients with AIDS; thus a small inoculum of ingested bacteria may produce disease. Mucosal immune function may also be impaired in those with a low CD4 count.
• Prolonged antibiotic use in HlV-infected individuals, eg. for PCP prophylaxis, may increase susceptibility to colonisation of bowel by organisms such as Clostridium difficile.
• Shellfish should be steamed for 4 6 minutes or avoided if such preparation cannot be assured; although this is a general recommendation for all individuals, an increased susceptibility to septicaemia from Vibrio spp. makes compliance with this guideline especially important for those who are immunosuppressed.
• Shigellosis in patients with AIDS may be protracted, severe, bacteraemic, and followed by chronic intestinal carriage.
• Non-typhoidal salmonellosis is characterised by recurrent bacteraemia in patients with AIDS.
• Campylobacter infections are also associated with bacteraemia and cholecystitis in HIV-infected persons, and may follow a chronic, relapsing course.
• Cryptosporidiosis causes a chronic infection in HIV-infected persons leading to malnutrition, wasting, and susceptibility to other infections.
• Isosporiosis in patients with AIDS has been associated with malabsorption, weight loss, and chronic watery diarrhoea.
• Microsporidiosis is another cause of chronic diarrhoea in patients with AIDS.
• Advise the HIV-infected traveller not to eat uncooked meat as it may cause toxoplasmosis, and to avoid soft, ripened cheeses which may carry the bacteria, Listeria.
• Individuals with chronic diarrhoea may be more susceptible to complications of superimposed traveller's diarrhoea (e.g. dehydration, weight loss). Antibiotic prophylaxis is worth considering for short trips.
• Drugs such as lomotil, loperamide (Imodium), the quinolones, erythromycin, ampicillin, tinidazole and metronidazole are safe. There is an increased risk of drug rashes with ampicillin, augmentin, ciprofloxacin, co-trimoxazole.

OTHER INFECTIONS

• Tuberculosis is a major threat to HIV-infected persons and has a high risk of progression to active disease. The risk for becoming infected during short-term travel is small l. The probability of exposure increases with longer visits. All HlV-infected persons should be tested with tuberculin skin test regardless of travel plans, although anergy limits the usefulness of the test, especially in those with advanced HIV infection.
• Some experts offer prophylaxis (isoniazid 300 mg daily) against tuberculosis to severely immuno-compromised patients (with CD4 counts less than 200) intending to travel to endemic areas for periods longer than a few weeks (i.e. other than the short trips to the usual tourist resorts).
• Leishmaniasis in HlV-infected persons is often an extensive disease with high mortality.
• The first manifestation may not appear for many months or years after exposure in endemic areas. The clinical. illness may be atypical, the serological tests are frequently negative, and the disease may be refractory to treatment. Travellers should be advised to avoid sandfly bites .

Medical Examination after travel: It is advisable (if not essential) to visit your local doctor promptly if you

• suffer from a chronic disease, such as cardiovascular disease, diabetes mellitus, chronic respiratory disease;
• experience illness in the weeks following their return home, particularly if fever, persistent diarrhoea, vomiting, jaundice, urinary disorders, skin disease or genital infection occurs;
• consider that you may have been exposed to a serious infectious disease while travelling;
• have spent more than 3 months in a developing country.

Source: WHO - http://whqlibdoc.who.int/publications/2005/9241580364_chap1.pdf  (page 8)