Epidemiological experience in the mission of the United Nations Transition Assistance Group (UNTAG) in Namibia.

Epidemiological data have rarely been generated during United Nations (UN) missions to Third World countries, even in situations where there is hardly any combat involvement. Continuous surveillance was therefore carried out during the 12-month stay of UN personnel in Namibia in 1989-90. In this population of 7114 persons, mostly young men, the mortality rate was 255 per 100,000; death was mainly due to traffic accidents. Hospitalization was chiefly because of fever of unknown origin or trauma. Repatriation to the country of origin was necessary in 46 patients, frequently for psychiatric reasons including alcoholism. Over this one-year period there were, on average, 2.7 new consultations per person for treatment (mostly for dental problems), and 0.8 per person for prophylactic measures. The extremely high mortality due to traffic accidents indicates a need for prevention. In the selection process for future missions, more emphasis should be given to the psychological and dental health of volunteers. All military contingents and civilian groups should learn about effective preventive measures prior to their arrival, and adhere to them.

PIP: Medical reports modelled after the US Peace Corps surveillance form provided mortality and morbidity data of the United Nations Transition Assistance Group in Namibia in 1989-1990. Contingents included Australians, Canadians, Danes, Finns, Kenyans, Malays, Poles, Spaniards, and Britons. Traffic accidents, mostly those on long distance journeys caused 14 of 16 deaths. The fatality ratio was 0.21/million km driven which was considerably higher than that in Switzerland 0.02/million km driven. Even though heavy traffic was not a problem in Namibia, limited experience on unpaved roads; high speeds induced by long and tedious driving; and reduced visibility caused by climactic conditions, fatigue, and alcohol contributed to high fatality. The hospitalization rate of 5.2% (369 patients) was rather high for a young and healthy population. The leading reasons for hospitalization included fever of unknown origin, trauma, and respiratory tract infections. Swiss Medical Unit physicians transferred 25 patients to the State Hospital in Windhoek, most for orthopedic surgery. Injuries, psychiatric problems, and alcoholism resulted in repatriation for 66% of 46 repatriated patients. New consultations for treatment averaged 2.7/person and those for preventive measures averaged 0.8/person. Helicopter pilots was the largest group returning for 2nd visits (56% compared to 1% for logistics staff). The major reasons for attending outpatient clinics included immunizations (18.8%), dental problems (10.5%), and respiratory infections (10.5%). In addition to respiratory infections, other frequent communicable diseases included diarrhea or dysentery, dermatological infections, sexually transmitted diseases, and confirmed or suspected malaria. Preventive measures are needed to reduce mortality due to traffic accidents and the prevalence of psychological and dental problems.

Epidemiological experience in the mission of the United Nations Transition Assistance Group (UNTAG) in Namibia

Epidemiological data have rarely been generated during United Nations (UN) missions to Third World countries, even in situations where there is hardly any combat involvement. Continuous surveillance was therefore carried out during the 12-month stay of UN personnel in Namibia in 1989-90. In this population of 7114 persons, mostly young men, the mortality rate was 255 per 100,000; death was mainly due to traffic accidents. Hospitalization was chiefly because of fever of unknown origin or trauma. Repatriation to the country of origin was necessary in 46 patients, frequently for psychiatric reasons including alcoholism. Over this one-year period there were, on average, 2.7 new consultations per person for treatment (mostly for dental problems), and 0.8 per person for prophylactic measures. The extremely high mortality due to traffic accidents indicates a need for prevention. In the selection process for future missions, more emphasis should be given to the psychological and dental health of volunteers. All military contingents and civilian groups should learn about effective preventive measures prior to their arrival, and adhere to them

Evaluation of immunization policies for peacekeeping missions.

This article first examines data bases available to assess the risk of vaccine-preventable diseases (VPD). In the second part, immunization recommendations and practices are briefly evaluated in view of the risk of exposure to VPD and of the efficacy and safety of available vaccines.

Prolonged reduction in basophil counts at cutaneous basophil hypersensitivity reaction sites challenged with antigen.

Previous studies have shown that injection of antigen into 24 hr cutaneous basophil hypersensitivity (CBH) reaction sites results in immediate degranulation of local basophils and release of mediators, such as histamine, that increase vascular permeability. In the current study, cell counts were made at these antigen-challenged CBH sites, 4, 8 and 24 hr later, and demonstrated a prolonged reduction of basophil numbers following antigen challenge. These results were interpreted to signify that mediators released by degranulating basophils led to inhibition of subsequent basophil accumulation. Local eosinophil infiltration was not inhibited, and in some cases was augmented. Local injection of histamine into CBH sites did not mimic the effect of antigen. It was concluded that one of the factors regulating accumulation of basophils at CBH sites was degranulation of basophils that had arrived previously.

Behaviour of human immunoregulatory cells in culture. I. Variables requiring consideration for clinical studies.

The suppressor function of lymphocytes stimulated with concanavalin A (Con A) provides a potential method for examining disorders of immunoregulation. Clinical application, however, requires definition of the culture conditions that influence the expression of normal suppressor cell activity. In the present studies culture conditions were modified until a sensitive assay for non-specific suppressor cell function was reproducible utilizing the response to varying doses of phytohaemagglutinin (PHA) as an indicator system. Practical conclusions included (1) that sensitivity was not lost if the suppressor cells and responder cells were allogenic; (2) that fresh responder cells were as sensitive as precultured responder cells; (3) that a wide range of Con A concentrations could induce suppressor activity; and (4) that the sensitivity of the assay was much enhanced by using suboptimal mitogen doses of PHA. Twelve percent of normal subjects gave false negative results but these could be avoided by studying cells at more than one time point after stimulation with Con A. Cells resting in culture for 7 days could be induced to suppress after stimulation with Con A and these suppressor cells were very sensitive to pharmacological doses of dexamethasone. Studies utilizing different times of cell pre-incubation before Con A stimulation and different periods of exposure to Con A revealed fluctuation in the induction of suppression that may represent alternating periods of suppression and amplifying activity among stimulated cells in vitro. Such variations will need to be taken into account in the application of this type of assay to clinical studies seeking disordered immunoregulation.

Lack of leukocyte migration inhibition by hepatitis B antigen and normal nonspecific immunoreactivity in asymptomatic carriers.

The immune response to hepatitis B surface antigen (HBS Ag) was studied in 25 asymptomatic carriers by the leukocyte migration-inhibition (LMI) test in agarose. In the presence of purified HBS Ag, inhibition was demonstrated in only four of 25 carriers, in contrast to 24 of 28 patients who cleared the antigen after acute infection with hepatitis B. Tuberculin purified protein derivative (PPD) was also used as an antigen for the LMI test in these carriers. Inhibition was demonstrated in only 12 of 25 individuals who had positive PPD skin tests, in contrast to all of 14 normal noncarrier individuals with positive PPD skin tests and none of 12 normal noncarrier of the asymptomatic carriers gave normal results. The lack of an immune response to HBS Ag was thought to be responsible for the persistence of the antigen and also for the absence of symptoms.