from sewage-contaminated water, raw fruits and vegetables, and contaminated milk and milk pro- ducts are important vehicles in some areas of the world. Typhoid  fever  is  communicable  as  long  as typhoid bacilli remain in the feces or urine. Many patients  not  appropriately  treated  become  perma- nent carriers. Specific antibiotics are the treatment of choice. Preventive  measures  include  (1)  in  field  situa- tions,  providing  for  the  sanitary  disposal  of human  feces, and   adequate   handwashing facilities; (2) ensuring that fly proof latrines are away  from  and  downstream  from  the  source  of drinking water; (3) controlling fly populations by screening,  with  insecticides,  and  by  the  proper  col- lection   and   disposal   of   garbage   to   prevent breeding  places; (4)   requiring   proper   food preparation  and  handling  and  proper  refrigera- tion; (5) at foreign ports, limiting the acquisition of  shellfish  to  supplies  from  approved  sources; (6)  instructing  patients,  convalescents,  and  car- riers  concerning  food  personal  hygiene;  (7)  ex- cluding  carriers  and  infected  persons  from  food handling.  Immunization  for  the  general  popula- tion in the United States is not recommended. Im- munization boosters are required for many Navy and  Marine  Corps  personnel  and  recommended for  travelers  to  endemic  areas. For  patients,  isolation  includes  enteric  precau- tions  while  they  are  ill.  Cases  should  not  be released  from  medical  supervision  until  three  con- secutive cultures of feces taken at 1 month inter- vals  after  the  onset  and  24  hours  apart  are negative. If any one of these cultures is positive, repeat at intervals of 1 month until three negative cultures  are  obtained.  Do  not  assign  household contacts to food handling until two feces cultures taken 24 hours apart are negative. The  probable  or  actual  source  of  every  case should  be  determined  by  searching  for  unreported cases,  carriers,  and  contaminated  food,  water, milk,  or  shellfish. Epidemic measures include (1) searching for cases, carriers, or contaminated food or water that may be transmitting the infections; (2) the exclu- sion  of  suspected  food;  and  (3)  disinfecting  all suspected water with chlorine or iodine, or boil- ing  it  before  use. During  natural  disaster  situations,  the transmission  of  typhoid  fever  may  be  expected with the disruption of food and water supplies and excreta  disposal  in  a  displaced  population  if  cases or  carriers  are  present.  Vaccination  of  such populations  is  not  generally  recommended;  efforts to provide safe food, water, and excreta disposal are  more  effective. Typhus Fever, Epidemic Louse-Borne Typhus  is  caused  by  rickettsial  agents,  similar to  bacteria.  The  onset  is  frequently  sudden  and commences   with   general   pain,   fever,   chills, headache,  and  prostration.  After  5  to  6  days,  a macular red rash becomes apparent on the upper trunk and then covers all the body, usually with the exception of the soles, palms, and face. Tox- emia is normally present. After about 2 weeks of fever, typhus ends with rapid recovery. Without specific treatment, the fatality rate is 10 to 40 per- cent  and  increases  in  older  persons.  Cases  may be mild with an absence of rash, particularly in children  and  persons  partially  protected  by  a previous   immunization.   In   the   Brill-Zinsser Disease,  typhus  recurs  (without  another  exposure) many  years  after  recovery  from  the  first  infection. The Brill-Zinsser disease is less serious with milder symptoms  and  has  a  lower  fatality  rate. Diagnosis  may  be  established  by  serological tests. In the past, outbreaks of typhus often accom- panied famine and war. Typhus is endemic in the mountainous  areas  of  Central  and  South  America, central  Africa,  and  many  countries  in  Asia.  In  the United  States,  the  infectious  agent  causes  a  disease in flying squirrels, which may be passed to man by their fleas. The infectious agent is Rickettsia prowazekii. The  reservoir  is  man.  Typically,  the  body  louse is infected when it feeds on the blood of a person with typhus fever. Man is infected by crushing and rubbing an infected louse or its feces into the bite wound or other break in the skin. Some cases may result  from  inhalation  of  dried  airborne  flea  feces. The  incubation  period  averages  about  12  days. Treatment is with antibiotics. Methods of control include control of lice with insecticide  dusts,  washing  clothes  and  bathing, and immunization of susceptible persons at high risk,  e.g.,  local  military  and  labor  forces  and residents. Management  of  patients,  contacts,  and  the nearby  environment  includes  (  1  )  no  requirement for  isolation  after  delousing  patients,  contacts, clothing,  and  quarters;  (2)  concurrent  disinfection of patients, contacts, bedding, and clothing with approved insecticides; (3) quarantine for 15 days for susceptible louse-infected persons exposed to typhus; and (4) surveillance of immediate contacts for  2  weeks. 11-24