Typhus Cases Reported in Texas

Texas health officials have issued an alert regarding the increasing number typhus cases reported in Houston and other parts of the state.

The Texas Department of State Health Services (DSHS) calls on healthcare providers to increase their "clinical suspicion" for patients with a fever, and one or more of the following symptoms, headache, myalgia, anorexia, rash, nausea/vomiting, thrombocytopenia, or any hepatic transaminase elevation.

The diagnosis of flea-borne typhus relies on a high-index of clinical suspicion, and on results of specific laboratory tests.

The most readily available diagnostic method to confirm infection with R. typhi is the detection of IgG antibodies to R. typhi, using an indirect fluorescent antibody (IFA) test in acute and convalescent serum specimens, collected at least 3 weeks apart, reports the DSHS.

As with other rickettsial infections, prompt treatment with doxycycline is recommended, and should not be delayed pending diagnostic tests. Additional clinician guidance on typhus can be accessed at the CDC website.

Typhus cases are required to be reported to the local health department within one week. Reports can be made to the Regional DSHS Zoonosis Control Office.

This DSHS alert says Texas can expect to see over 400 typhus cases during 2017.  Since 2003, eight deaths have been attributed to typhus infections in Texas.

The case-fatality rate is between 1% and 20%, according to the World Health Organization (WHO). The WHO does not have a vaccine against typhus in its registry.

Flea-borne typhus is caused by infection with the bacterium Rickettsia typhi (or R. felis).

Transmission to humans can occur when infected flea feces are scratched into a bite site or another abrasion on the skin, or rubbed into the conjunctiva. Rats, opossums, and cats are thought to be the primary reservoirs for the disease in Texas.

Typhus is often found in the colder mountainous regions of Africa, South America and Asia.

Many people confuse typhus and typhoid.

This confusion often creates problems for travelers as they prepare to depart.

Typhoid is a foodborne illness that infects an estimated 21 million people each year. More than 200,000 people die from typhoid every year. Typhoid is often transmitted through contaminated food or water, and symptoms develop within three weeks.

There is a typhoid vaccine that is recommended for most travelers visiting undeveloped nations.