Because leptospirosis has been an important cause of morbidity in U.S. soldiers training in the Republic of Panama, we conducted a randomized, double-blind, placebo-controlled field trial during the fall of 1982 to determine whether doxycycline was an effective chemoprophylactic agent against this infection. Doxycycline (200 mg) or placebo was administered orally on a weekly basis and at the completion of training to 940 volunteers from two U.S. Army units deployed in Panama for approximately three weeks of jungle training. Twenty cases of leptospirosis occurred in the placebo group (an attack rate of 4.2 per cent), as compared with only one case in the doxycycline group (attack rate, 0.2 per cent, P less than 0.001), yielding an efficacy of 95.0 per cent. This study demonstrated the value of doxycycline as a prophylactic drug against leptospirosis.

A pool of whole-mouth saliva collected from five human carriers of hepatitis B surface antigen, subtype adr, was found to contain antigen particles with mean diameters of 23.3 and 41.8 nm as seen by immune electron microscopy. Two gibbons received subcutaneous injections of the pooled saliva and developed serological and, in at least one animal, biochemical evidence of hepatitis B virus infection at 12 and 22 weeks, respectively. Although none of eight other gibbons that were exposed by the nasal or oral routes were infected, the experiment demonstrated that human saliva can serve as a vehicle for the transmission of hepatitis B virus.

No abstract

A survey of hepatitis B patients, asymptomatic hepatitis B antigen (HB8Ag) carriers, and control subjects was conducted to determine the relationship between antigenemia and antigen excretion in saliva, urine, and stool. Radioimmunoassay was used to detect HB8Ag. Specificity-confirmed HBeAg was detected in the saliva of 6 (30%) of 20 antigenemic patients, 1 (5%) of 20

A sustained outbreak of viral hepatitis occurred at an Army base in Texas between January 1971 and June 1973. Seven hundred ninety-two admissions but no deaths were recorded in a military population of 35,000. Cases were sporadic, with highest attack rates in low-ranking soldiers with disciplinary problems. Twenty-nine per cent of patients had histories of intravenous drug use within six months prior to hospitalization; most of the rest had close personal contact with jaundiced persons. Of 505 patients tested, 31% were seropositive for hepatitis B antigen (HBSAg) by counterelectrophoresis. Comparison of 38 hepatitis patients (cases) to 34 orthopedic patients (controls) revealed marked differences in rates of exposure to jaundiced persons are shared needles. Sixteen (94%) of 17 antigenemic cases tested were of subtype ayw. Seven (78%) of nine NBSAg-negative cases tested were antibody (anti-HBS) positive three months later.

No abstract

Malaria remains a major cause of military casualties in Southeast Asia. The numerous conflicts in the region have been greatly affected by malaria. Besides guerrilla warfare, refugees and other civilian movements across international borders contribute heavily to the continuing problem of multiple drug-resistant malaria. Drug resistance is an increasing problem with few available prophylactic options. The malaria threat to any potential deployment of United States military forces remains unsolved.

To determine the incidence of clinical and inapparent hepatitis in a US military population stationed in Thailand, the authors prospectively studied a cohort of 326 men during one year. Clinical hepatitis A occurred in one man (clinical attack rate = 3.1/1000 men/year), and clinical hepatitis B was found in four men (clinical attack rate = 12.3/1000 men/year). No non-A, non-B hepatitis was identified. There was no serologically identified inapparent hepatitis A but inapparent hepatitis B occurred in 17 men. The apparent/inapparent ratio for hepatitis B was 1:4.25. Serotype analysis suggested that hepatitis B virus largely originated from Thai contacts, although 23% of cases were derived from western sources. To determine the relative contribution of 16 statistically significant (out of 67 studied) behavioral variables to the transmission of HBV, a factor analysis and a multivariate correlation analysis were employed. Factor analysis indicated that social and sexual contact with the indigenous population, including prostitutes, residence within the Thai community and marijuana use were behavioral areas that were associated with the acquisition of hepatitis B. Residence in the Thai community during the first four-month period in Thailand, sexual contact with a prostitute during the third four-month period, and ever having maintained a Thai mistress were found to be significant and independent risk factors by multiple regression analysis.