Chloroquine and Typhoid vaccine (live), oral

• Generic Name: chloroquine
• Dosage Forms: n.a.
• Other Brand Names: Aralen Phosphate, Aralen Hydrochloride

Chloroquine is an anti-malaria medicine that works by interfering with the growth of parasites in the red blood cells of the human body.

Parasites that cause malaria typically enter the body through the bite of a mosquito. Malaria is common in areas such as Africa, South America, and Southern Asia.

Chloroquine is used to treat and to prevent malaria. Chloroquine is also used to treat amebiasis (infection caused by amoebae).

Chloroquine may also be used for purposes not listed in this medication guide.

• Generic Name: typhoid vaccine, live
• Dosage Forms: n.a.
• Other Brand Names: Vivotif Berna

Prevention of Typhoid Fever

Prevention of typhoid fever in US travelers planning to visit areas with a recognized risk of exposure to Salmonella enterica serovar Typhi.

Prevention of typhoid fever in individuals with intimate exposure (e.g., household contact) to a known typhoid carrier.

Prevention of typhoid fever in laboratory personnel with frequent contact with Salmonella Typhi bacilli.

Typhoid fever is a potentially severe and occasionally life-threatening, febrile, enteric illness caused by Salmonella Typhi. Usually acquired by ingestion of food and/or water contaminated with feces from individuals who have typhoid fever or are chronic typhoid carriers. Overall case-fatality rate in patients who receive early and appropriate antibacterial treatment is typically <1%; if left untreated, case-fatality rate may be ≥10–20%. Approximately 2–4% of individuals with acute typhoid fever develop a chronic carrier state.

Typhoid fever is uncommon in the US, but endemic in many less well-developed areas of the world that have poor sanitation and primitive water systems. About 22 million cases of typhoid fever and about 200,000 typhoid-related deaths occur annually worldwide. In the US, about 300–400 confirmed cases of typhoid fever are reported annually, almost all in recent travelers to other countries (most commonly southern Asia).

USPHS Advisory Committee on Immunization Practices (ACIP) and CDC state that routine vaccination against typhoid fever not recommended for individuals residing in the US, but preexposure vaccination is recommended for those at high risk of exposure to Salmonella Typhi.

When vaccination against typhoid fever indicated, either typhoid vaccine live oral Ty21a or typhoid Vi polysaccharide vaccine can be used unless contraindicated. Consider that the vaccines have different contraindications (see Contraindications under Cautions) and different minimum age limits for use in children (see Pediatric Use under Cautions). Other factors to consider when selecting a typhoid vaccine include immunization schedule, response time, patient compliance, storage facilities, and immunocompetence of the vaccinee (see Warnings/Precautions under Cautions). Because typhoid vaccine live oral Ty21a is self-administered over a 1-week period and compliance errors (i.e., dosing errors, improper storage) may occur, typhoid Vi polysaccharide vaccine may be preferred if compliance is likely to be a problem.

Efficacy of typhoid vaccine live oral Ty21a and typhoid Vi polysaccharide vaccine appear to be comparable when administered as recommended; neither vaccine is expected to provide protection against typhoid fever in all vaccine recipients.

Typhoid vaccines will not provide protection against S. enterica serovar Paratyphi or any Salmonella other than Salmonella Typhi and will not provide protection against other bacteria known to cause enteric disease.

Typhoid vaccines are not used for treatment of typhoid fever and should not be used in individuals with acute Salmonella Typhi infection or in chronic typhoid carriers.

There is no evidence to support use of typhoid vaccine to control common source outbreaks or disease following natural disasters or in individuals attending rural summer camps.