The United States last year saw a sizable drop in the number of tuberculosis cases, but missed its goal of eradicating the disease by 2010, US health officials said Thursday.

The Centres for Disease Control and Prevention (CDC) wrote in its Morbidity and Mortality Weekly Report that the number of TB cases hit an all-time low in 2010, with only 11,181 cases reported to public health authorities, a 3.9 per cent drop in the number of cases compared to one year earlier.

But the US had hoped to eradicate the disease altogether, a goal US health experts said they were disappointed not to have met.

The CDC said that in six out of 10 cases, TB patients were born outside the US, and in more than half of the cases came from one of four countries: Mexico, the Philippines, India or Vietnam. US health official said foreign-born people were 11 times as likely to have TB as those born in the US.

The CDC said four states acc-ounted for about half of the US cases of tuberculosis: California, Texas, New York and Florida.

The illness also was more prevalent among members of ethnic minority groups: TB rates among Hispanics, blacks and Asians were seven, eight and 25 times as high as among Caucasians, respectively.

Tuberculosis is caused by the mycobacterium tuberculosis bacterium, and can be cured with antibiotics.

However, a full course of treatment requires six to nine months to completely eradicate the microorganism, and many people do not finish the full treatment, which leads to the development of drug-resistant strains of the disease.