TYPHOID

1.      HISTORY

In 430 BC, a plague, which some believed to have been typhoid, killed one-third of the population of Athens, including the leader Pericles. Some historians believe that English colony of Jamestown Virginia, died out due to typhoid. Typhoid fever killed more than 6000 settlers in new from 1607 to 1624 [43]. During the Spanish-American war, American troops were exposed to typhoid fever due to inadequate sanitation system. Consequently more soldiers died of typhoid than the war wounds.

            The most notorious incident of typhoid was Mary Mallon (a cook in New York), also known as typhoid marry. She was the first carrier of typhoid in USA in 1907. She was found to be closely associated with 53 typhoid cases and 3 deaths [47]. The public health authorities asked Mary to quit her job or have her gall bladder removed, as she had chronic infection that kept her active as a typhoid disease carrier. Mary quit her job but returned late under a false name. But she was detained and quarantined after another typhoid outbreak. She died of pneumonia after 26 years of quarantine[i].

2.      CAUSATIVE AGENT

It is caused by Salmonella typhi. However, the organisms like Salmonella paratyphi and Salmonella schottmilleri may also cause this disease. The Salmonella vary in length. Most of these are motile and have peritrichous flagella. They grow readily on simple media.

3.      SOURCE OF INFECTION AND TRANSMISSION

The bacterial infection takes place through food and water contaminated by human faeces. The infection my occur through milk and other dairy products. The infectious dose seems to be quite high and may be more than 10⁵ organisms. In areas with very poor sanitation, the bacteria may get transmitted through house flies.

4.      SYMPTOMS

The salmonella reach the small intestine and from there they penetrate the epithelial lining. Then the bacteria are phagocytozed by the macrophages, within which they actively multiply. The macrophages transmit the salmonellae throughout the body. These even occur during first week of infection which is accompanied by fever, aches and pains.

Extended bacteremia[ii] occurs in the second week. Generally the gall bladder becomes infected. From the gall bladder the bacteria may shed into the intestinal lumen. During this time, ulcerative lesions (rose spots) appear on the lower chest and abdomen in some patients.

In untreated cases, the patients is exhausted by the third week.

After people recover from clinical disease, the S. Typhi may continue to multiply in the gall bladder, who may become chronic carrier and serve as source of future typhoid outbreaks.

Upto 10% of patients may die of this disease.

5.      PREVENTION

a.       Proper sewage treatment

b.      Pasteurization of milk

c.       Vaccines: although killed vaccines have been used for many years, they are of limited value. The vaccine reduces the chances of getting typhoid disease to 30-70 %.

6.      TREATMENT

Antibiotics like ampicillin and chloramphenicol are used for the treatment of typhoid fever. Treatment must be continued for several weeks to ensure killing of bacteria that becomes sequestered[iii] in the body.

Trimethoperim, sulfamethoxazole and mumoxillin are excellent alternatives to ampicillin.

7.        

          REFERENCES/FURTHER STUDIES

1.        Sobti, R. C., Medical Zoology

2.        Byrne, Joseph Patrick (2008), Encyclopedia of pestilence, pandemics and plagues: ISBN 0-313-34102-8

3.        Nova: the most dangerous women in America

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[i] A state or place of isolation in which people or animal exposed to infectious diseases is placed.

[ii] the presence of bacteria in the blood

[iii]  Isolated and hidden away.