Evidence of smallpox was found in Egyptian mummies dating back to 1570 B.C. It was discovered in the New World in the 16th century, and continued as a killer till the 17th century in England. A plague pandemic occurred in 540 A.D. at Pelusium, Egypt (Plague of Justinian), and swept across Europe, Constantinople, Alexandria and Asia, killing 13 million people before it ended in 760 A.D. The curse reappeared in 1345 (Black Death) and ended in 1366, and the third wave, from 1873 to 1894, also affected India and killed an estimated 12.5 million Indians.

The influenza pandemic (1918-1919) started in the USA, spread to Europe, New Zealand, India and South Africa, and affected almost one quarter of the entire population. Leprosy devastated Europe in the 6th, 7th, and 13th centuries. Now we are faced with another killer, the HIV. The first cases were identified in San Francisco and New York in 1981, and it is still rampaging.

HIV (Human Immunodeficiency Virus) destroys the defense cells called CD4 helper lymphocyte and the body's natural defense mechanism called immunity, exposing humans to many infections and cancers. Later, a complex phenomenon called Aids (Acquired Immunodeficiency Syndrome) develops, and this is what kills.

Till the end of 2006, 39.5 million people were living with HIV/Aids, 2.9 million died in 2006, 4.3 million got newly infected, and 25 million died since 1981. Around 63% of the people living with HIV are in sub-Saharan Africa (24.7 million cases). Approximately 33 million people in Africa are living with HIV/Aids, and 7.1 million in Asia. A study in South Africa has indicated that by the year 2020, the level of GDP could be lowered by 17 percent due to HIV/Aids, while the level of per capita GDP could be lower by 7 percent.

The first case of HIV in Bangladesh was detected in 1989. Official sources show that 874 HIV cases were detected from 1989 to 2006. There were 240 Aids cases, of which 109 died. But the World Fact Book shows that 13,000 people in Bangladesh are living with HIV/Aids, with 650 deaths, because there is significant under-reporting of the cases due to the limited voluntary testing and counseling capacity.

UNAids shows that an estimated number of 11,000 HIV cases are adult male (15-49 years), 1400 are adult female, and 481 (3.7%) are infants & children. Its prevalence rate is below 1%, which is far below the 5% rate to turn into epidemic proportions. At the present level of prevalence it may not look like a major threat, but, in a population of more than 14 million, a mere rise of 1% would mean an addition of more than a million to the numbers.

Commercial sex workers (CSW), male gays having sex with multiple partners, intravenous drug users, and professional blood donors, are the main sources of HIV/Aids in Bangladesh. The situation is augmented by certain social factors like poverty, gender discrimination, denial, low prevalence of health facilities, lack of reproductive knowledge, illiteracy, high risk behaviour, high prevalence of other sexually transmitted diseases, multi-partner sexual activities, migration and migrant workers, and HIV/Aids situation of our neighbouring countries.

National surveys indicate that the rate of HIV infection among the street-based sex workers in central Bangladesh is higher, compared with sex workers in other parts of South Asia. Sex workers in Bangladesh have a higher client turn-over rate than any other South Asian country, and the use of condoms during paid sex is rare (0-12%, depending on the region). There are over 105,000 sex workers, both female and male. Brothel-based female sex workers reportedly see around 18 clients per week, while street-based and hotel-based workers see an average of 14 to 44 clients, respectively, per week. In a survey in Dhaka in 1996, 0.2% of the sex workers tested positive for HIV.

It is generally accepted that truck drivers have been, and continue to be, a main force in the spread of HIV to epidemic proportion. Almost 80% of the truck drivers see CSWs frequently. Many truck drivers have many sex partners, and one-third reported in a study that they had more than 50 partners. Truck drivers and commercial sex workers are the main transmitters of HIV/Aids, and become a pool in their local community. CSWs transmit the disease to the high-risk group, and the high-risk group spreads it in its own community, and the vicious cycle continues.

Sharing of needles among intravenous drug users (IDU) is another most important mode of transmission of HIV in Bangladesh. A national survey data indicates that HIV incidence among IDUs jumped from 1.8% in 2001 to more than 4% in 2004. In one Dhaka "hotspot" the prevalence has jumped to 9%. A survey in central Bangladesh revealed that more than 70% IDUs routinely share needles. This is comparable to levels in countries that are experiencing a concentrated and growing HIV epidemic.

A large section of IDUs have aberrant sex behaviour, and among them only one in ten used a condom during commercial sex (Ministry of Health and Family Welfare, 2004). The fourth round of national HIV and behavioural survey reports that HIV infection rate among the IDUs is now 4%, up from 2.5% previously, and is just short of the 5% mark of a concentrated epidemic. UNDP has estimated that between 500,000 and 1,000,000 people in Bangladesh are addicted to drugs.

In Bangladesh, the culture of donating blood is not yet fully developed, thus, professional blood donors remain the main source of blood in an emergency. A study found that among the professional blood donors almost 48.7% are IDUs, and 37.9% visit the brothels or have sex with street sex workers. These donors remain a potential source of HIV.

Bangladesh has another geographical disadvantage with regard to HIV/Aids, as India and Myanmar are our neighbouring countries. It is estimated that in India 5.7 million people are infected with HIV, with an estimated 270,000-680,000 deaths due to Aids in 2005. As of August 2006, most of all nationally reported Aids cases have been found in 10 out of 38 states. The greatest numbers were in Maharashtra and Gujrat in the west; Tamil Nadu, Andhra Pradesh and Karnataka in the south; and Manipur and West Bengal in the north-east. There is frequent mobility of Bangladeshis across the border to all these states, and any contact with the CSWs there is likely to infect that individual, and he will come back with the disease to infect many more within the country. Myanmar, with 1,30,000 people living with HIV/Aids, has an estimated adult prevalence rate of 1.6%. So trans-border movements have made Bangladesh more vulnerable to HIV.

There is a great risk of HIV flaring up at any time in Bangladesh. In a country where poverty, illiteracy and poor health are rife, the threat of spread of HIV presents a daunting challenge. It is not only a public health issue, but also one which will affect the economic and developmental pace of the society. It will wipe out the adult population of a country, who are the driving economic force, besides orphaning scores of families. It will also break down the notion of progress and growth of our country.

Dr. Zulfiquer Ahmed Amin is a freelance contributor to The Daily Star.