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From the discovery of Zika virus in Uganda in 1947 through 2007, when an outbreak occurred on Yap Island, Micronesia, only sporadic cases of human infection had been reported (1). [...]

International travel is markedly increasing. In 2010, an estimated 940 million tourists arrived at international destinations, more than twice the 435 million in 1990 (1). Trips to developing regions have [...]

Travelers have many reasons for long durations of travel, including diplomatic work, education and research, missionary work, Peace Corps volunteer (PCV) work, military operations, backpacking trips, and corporate expatriate assignments [...]

Dengue, the most common arbovirus infection globally, is transmitted by mosquito vectors. Healthcare-related transmission, including transmission by blood products, has been documented, although the frequency of these occurrences is unknown. [...]

The tolerability of mefloquine with particular focus on its neuropsychiatric adverse effects and influence on performance is studied. Prevention of malaria in travelers requires detailed knowledge of malaria epidemiology and host-vector-parasite interactions.

The treatment of infectious diseases that can affect travelers is reviewed. Topics include malaria, dengue, rickettsia, leptospirosis, typhoid fever, and other infections that cause fever, diarrhea, and skin lesions.

A combination of more effective treatments, greater coverage and vaccination against tuberculosis (TB) may be needed to achieve the goal of controlling TB in the US. Researchers used a computer simulation to estimate the effectiveness of one or all of these factors in reaching the goal of 3.5 TB cases per 100,000 people by the year 2000. The rate in 1994 was 9.4 per 100,000 people. Only a combination of all factors would achieve this goal, leading to a 47% drop in TB cases and a 50% reduction in deaths from TB., Objective.--To develop more effective methods to assess tuberculosis (TB) control strategies so we can meet national goals for the elimination of TB in the United States. Design.--Using a semi-Markov model that divided the US population into 3 age groups and 18 clinical states based on disease status and risk for TB and human immunodeficiency virus (HIV) infection, we measured the effects of 5 changes in TB policy, introduced singly and in combination: (1) increased coverage and (2) improved efficacy of preventive therapy, (3) increased coverage and (4) improved efficacy of treatment, and (5) introduction of BCG vaccination. Results.--A BCG vaccination program that reached 10% of eligible children and 1% of eligible adults each year would produce a 17% reduction in cases and an 11% decline in deaths over 10 years. Preventive therapy programs among the general population would have little effect on the number of TB cases, but a program targeting HIV-infected patients would reduce HIV-associated TB cases and deaths 14% to 20%. A 10% improvement in the coverage and efficacy of both preventive therapy and treatment, coupled with the BCG vaccination program, would lead to a 47% decline in TB cases and a 50% decline in TB deaths relative to baseline over 10 years. Conclusions.--Improvements in treatment coverage or effectiveness alone are unlikely to reach established national goals for the elimination of TB. These goals can be achieved through a combination of improvements in current programs with targeted preventive therapy and BCG vaccination programs. JAMA. 1996;276:1898-1903

The bacillus Calmette-Guerin (BCG) vaccine appears to be effective in immunizing infants against tuberculosis, and should receive wider use. Researchers reviewed published data from four randomized control trials and nine case-control studies. The BCG vaccine was generally judged effective in reducing the risk of tuberculosis, deaths from TB, and tuberculosis meningitis. The risk of contracting TB was reduced by 74% in the trials and 52% among the case-control studies. Wider use of the BCG vaccine is being recommended because of the increase in TB cases and the development of drug-resistant strains of mycobacterium tuberculosis., Objective. To quantify the efficacy of vaccination of infants with bacillus Calmette-Guerin (BCG) against tuberculosis. Data sources. MEDLINE with index terms BCG vaccine, tuberculosis, and human; lists of all known studies provided by experts at the Centers for Disease Control and Prevention, the World Health Organization, and other organizations. Study selection. A total of 1264 articles and abstracts were reviewed for details on BCG vaccination, the availability of concurrent vaccinated and unvaccinated groups, and a tuberculosis outcome. Seventy articles were reviewed in depth for method of vaccine allocation used to create comparable groups, age at vaccination of study participants, comparability of surveillance and follow-up of recipient and concurrent control groups in trials, an appropriately defined control group in case-control studies, and outcome measures (tuberculosis cases and/or deaths). Five prospective trials and eleven case-control studies of vaccination during infancy were included in the present analyses. Data extraction. We recorded study design, age range of study population, number of patients enrolled, efficacy of vaccine, location of the study, and a series of items to assess the potential for bias in study design, follow-up, and diagnosis. We extracted or computed vaccine efficacy by years since vaccination wherever possible. At least two readers independently extracted data and evaluated data validity. Data synthesis. The relative risk (RR) or odds ratio (OR) for tuberculosis in vaccinated versus unvaccinated infants was the measure of vaccine efficacy analyzed. A random-effects method estimated a weighted average RR or OR from data extracted from the trials and case-control studies. The protective effect was then computed by 1 -- RR or 1 -- OR. Overall, the protective effect of vaccination against cases of tuberculosis was 0.74 (95% confidence interval [95% CI], 0.62 to 0.83) when estimated from four randomized controlled trials, and 0.52 (95% CI, 0.38 to 0.64) when estimated from nine case-control studies. Five trials reporting deaths from tuberculosis showed a BCG protective effect of 0.65 (95% CI, 0.12 to 0.86), five studies reporting on meningitis showed a protective effect of 0.64 (95% CI, 0.30 to 0.82), and three studies of disseminated tuberculosis showed a protective effect of 0.78 (95% CI, 0.58 to 0.88). Three case-control studies included separate results for laboratory-confirmed cases of tuberculosis. These studies documented a protective effect of 0.83 (95% CI, 0.58 to 0.93). In a random-effects regression model of the nine case-control studies, study validity score explained 15% of the heterogeneity among study-estimated protective effects, suggesting that better studies reported greater efficacy. Three trials and six case-control studies provided some age-specific information that allowed us to examine the duration of BCG efficacy. Most of this evidence suggested that BCG efficacy may persist through 10 years after infant vaccination. Conclusion. BCG vaccination of newborns and infants significantly reduces the risk of tuberculosis--by over 50%, on average. Protection has been observed across many populations, study designs, and forms of tuberculosis. Rates of protection against cases that are confirmed by laboratory tests, reflecting reduced error in disease classification and consequently more accurate estimates of BCG efficacy, are highest at 83%. Pediatrics 1995; 96:29--35; bacillus Calmette-Guerin vaccination, tuberculosis, infants, meta-analysis., ABBREVIATIONS. TB, tuberculosis; BCG, bacillus Calmette-Guerin vaccination; WHO, World Health Organization; CDC, Centers for Disease Control and Prevention; RR, relative risk; OR, odds rates; CI, confidence interval. The resurgence of [...]

Bacillus Calmette-Guerin (BCG) vaccine appears effective in reducing the risk of tuberculosis (TB). A total of 1,264 articles on BCG vaccination were reviewed. Seventy articles were studied in greater depth for analysis and comparison of results. Analysis of the studies indicates that vaccination with BCG appears to reduce the risk of TB by approximately 50%. In the seven studies that reported deaths from TB, vaccination with BCG reduced the risk of death from TB by 71%. In the five studies of BCG vaccination in infancy and risk of tuberculous meningitis, vaccination reduced the risk of meningitis by 64%. BCG vaccine appeared effective in lowering the risk of TB both in the lungs and in other organs. The advantages of vaccination appeared regardless of study design or geographic location and across many populations., Objective. - To quantify the efficacy of BCG vaccine against tuberculosis (TB). Data Sources. - MEDLINE with index terms BCG vaccine, tuberculosis, and human. Experts from the Centers for Disease Control and Prevention and the World Health Organization, among others, provided lists of all known studies. Study Selection. - A total of 1264 articles or abstracts were reviewed for details on BCG vaccination, concurrent vaccinated and unvaccinated groups, and TB outcome; 70 articles were reviewed in depth for method of vaccine allocation used to create comparable groups, equal surveillance and follow-up for recipient and concurrent control groups, and outcome measures of TB cases and/or deaths. Fourteen prospective trials and 12 case-control studies were included in the analysis. Data Extraction. - We recorded study design, age range of study population, number of patients enrolled, efficacy of vaccine, and items to assess the potential for bias in study design and diagnosis. At least two readers independently extracted data and evaluated validity. Data Synthesis. - The relative risk (RR) or odds ratio (OR) of TB provided the measure of vaccine efficacy that we analyzed. The protective effect was then computed by 1-RR or 1-OR. A random-effects model estimated a weighted average RR or OR from those provided by the trials or case-control studies. In the trials, the RR of TB was 0.49 (95% confidence interval [Cl], 0.34 to 0.70) for vaccine recipients compared with nonrecipients (protective effect of 51%). In the case-control studies, the OR for TB was 0.50 (95% Cl, 0.39 to 0.64), or a 50% protective effect. Seven trials reporting tuberculous deaths showed a protective effect from BCG vaccine of 71% (RR, 0.29; 95% Cl, 0.16 to 0.53), and five studies reporting on meningitis showed a protective effect from BCG vaccine of 64% (OR, 0.36; 95% Cl, 0.18 to 0.70). Geographic latitude of the study site and study validity score explained 66% of the heterogeneity among trials in a random-effects regression model. Conclusion. - On average, BCG vaccine significantly reduces the risk of TB by 50%. Protection is observed across many populations, study designs, and forms of TB. Age at vaccination did not enhance predictiveness of BCG efficacy. Protection against tuberculous death, meningitis, and disseminated disease is higher than for total TB cases, although this result may reflect reduced error in disease classification rather than greater BCG efficacy.

To the Editor: Although tickborne rickettsioses are widespread globally, few reports document their presence in Central America (1). Serosurveys detected rickettsial antibodies in humans in Central America in 1971 in [...]

Modern Factors in the Spread of Disease On March 30, 2001, the US Centers for Disease Control and Prevention (CDC) in Atlanta was notified of an outbreak of acute respiratory [...]

Vaccinating all homeless people against tuberculosis and improving access to tuberculosis treatment facilities may reduce the impact of this disease on the homeless population. The rate of tuberculosis among the homeless is estimated to be 20 times greater than in the general population.

Global action is needed to eradicate multi-drug resistant tuberculosis (MDRTB). MDRTB now exists in every country except Kenya. The best treatment is directly observed treatment, short-course (DOTS). This treatment involves giving patients medication and then watching them take it. However, DOTS is expensive and many developing countries cannot afford it. DOTS alone is not effective as seen in countries that use DOTS but whose rate of MDRTB remains the same. However, many hospital and community-based treatment programs have cure rates of 85% or more. It may be more expensive in the long run not to treat MDRTB.

To the Editor: Emerging infections have been defined as diseases whose incidence in humans has increased within the last 2 decades or threatens to increase in the near future (1). [...]

The serious threat posed to public health by infectious disease may best be combatted by initiatives that take into account underlying social factors that make humans susceptible to disease. A recent study showing the disproportionate occurrence of tuberculosis, AIDS and death among substance abusing welfare clients in New York City indicates the social dimension of disease transmission. Synergy between tuberculosis and AIDS, overcrowded living conditions, and limited access to health care are some factors making infectious disease particularly potent among the poor. The impact of these health problems may be felt beyond the indigent groups most affected. Drug-resistant tuberculosis, the ability of tuberculosis to spread in any closed room, and the heterosexual transmission of HIV from intravenous drug users are some major causes for concern. The specific targeting of vulnerable populations for disease prevention, as exemplified by needle exchange programs or aggressive tuberculosis case finding and treatment, has shown promise and should continue to be an effective approach.

Doctors should consider the possibility of furuncular myiasis in patients that develop skin lesions that do not heal after travel to tropical areas. Furuncular myiasis refers to the infestation of the skin with fly larvae. The cases of four patients are discussed. The patients had lesions with central openings from which the larvae occasionally protruded. The patients were treated with raw bacon placed over the central openings. After three hours, the larvae had migrated into the bacon and could be grasped and removed with tweezers. After treatment, the lesions healed without complications. Antibiotic treatment is only necessary in cases where secondary infection develops. Furunculosis may develop after travel to central and south America and Africa.

The risk of malaria in long-term travelers, and the safety and tolerability of malaria chemoprophylaxis during long-term use is examined and prevention strategies including continuous chemoprophylaxis, stand-by emergency self-treatment and seasonal prophylaxis are considered. The results suggest that prevention of malaria in long-term travelers is a complex issue, requiring expert advice from travel medicine specialists and the recommendations for prevention must be individualized.

To the Editor: Wagner and colleagues report nosocomial dengue transmitted by needlestick and note that it is the fourth case of nosocomial dengue to their knowledge (1). In the same [...]