Infectious Diseases

The questions below were raised by visitors to the STOMP (Straits Times Online Mobile Print) website in the AskST section of the website. eMenders doctors provided the answers to the questions raised as a public health education project. The information provided below is of a general nature and should not be treated as a replacement for medical advice. You should seek consultation from a medical or healthcare professional about your specific medical condition.


All infected HIV individuals can transmit the virus to others via sexual intercourse or other means. The degree of infectiousness varies with the stage of disease and the mode of transmission.

What is ‘under control’ ? This term can mean different things to different people. We generally take an undetectable viral load (< 50 copies) and normal CD4 counts in an asymptomatic patient as ‘well controlled’.

Kissing carries a trivial risk and the presence of oral lesions and blood in the saliva can increase this risk. Condoms provide good protection against sexually transmitted diseases if used correctly – but accidents can happen. If used correctly, it gives > 97 % protection. Unprotected sex (not using a condom) increases one’s risk of acquiring disease. As long as you are aware of the risk, you can make an informed decision about having unprotected sex but this is not advisable.

Contributed by Dr Lam Mun San, eMenders Infectious Diseases Physician.

The best way to find out if you are immune is to do an antibody test for the chicken pox antibody. If you are immune, there is no need for a vaccination.

If you are non-immune, you can go for a vaccination which must be done before you get pregnant. Because this is a live viral vaccine, you cannot take it during pregnancy.

There is a < 4% incidence of a minor eruption of chicken pox after vaccination.

Contributed by Dr Lam Mun San, Infectious Diseases Physician.

If you are vaccinated, you have to check your antibody levels to be sure you have made adequate antibodies to protect you against infection.

About 10 % of vaccinated patients do not make antibodies to the vaccine and sometimes a second series of vaccination may be recommended.

Contributed by Dr Lam Mun San, Infectious Diseases Physician.

For travel to developing countries like Indonesia, many doctors will recommend routine immunisation with hepatitis A, B and typhoid vaccines. Depending on itinerary, sometimes, malaria pills may be needed.

Please consult a travel clinic at Tan Tock Seng or Changi General Hospital or the government Polyclinic if cost is a problem, otherwise personalised travel advice is available in the private sector.

Contributed by Dr Lam Mun San, Infectious Diseases Physician.