Updates

By Carol A. Kemper, MD

Butchers: On the Cutting Edge

Source: Mevorach D, et al. Am J Med 1999;106:479-80.

Hepatitis b virus infection is a potential occupational hazard for almost anyone working with people and sharp instruments, although we do not usually think of pedicurists, acupuncturists, and butchers when discussing hepatitis B. Mevorach and colleagues examined the seroincidence of hepatitis B exposure in 123 employees in 10 butcheries and three slaughterhouses in Jerusalem, Israel. Individuals with a prior history of transfusion were excluded from the study.

More than one-half of the butchers reported at least one hand cut per week, and 88% cut themselves at least once monthly. Mevorach et al found that butchers who routinely used knives in their daily activities were at significantly greater risk for hepatitis B infection than their co-workers who did not. Thirty of 82 (37%) butchers were hepatitis B core antibody-positive, compared with seven of 41 (17%) nonbutchers (P < 0.05). At work sites where at least one worker was positive for hepatitis B surface antigen, 16 of 28 (57%) butchers had evidence of exposure compared with only 26% at sites where no one was infected. Four of five butchers at one site alone where a single butcher was found to be hepatitis B antigen positive (and therefore at greater risk for transmitting infection) had evidence of exposure to hepatitis B. None of the employees had serological evidence of hepatitis C infection.

These data strongly support the need to provide hepatitis B vaccination to food handlers, especially those who work with cutting utensils. They additionally imply that in the course of daily business, knives must have been shared by several butchers in these facilities, and obviously must not have been sufficiently cleaned between jobs. While there is no evidence that meat handled by butchers infected with hepatitis B is potentially contagious, this possibility was not specifically examined.

Which of the following statements is correct?

    a. Hepatitis B may be transmitted from beef to food handlers.
    b. Serologies indicate that 87% of butchers in Israel have been exposed to hepatitis B virus.
    c. Food handlers who share knives should have the hepatitis B vaccination.
    d. Hepatitis B virus can be transmitted to people who eat meat.


Odd Occupations Resulting in Fungal Disease

Sources: ProMED-mail post, February 12, 1999. www.healthnet.org. Jones TF, et al. Am J Med 1999;106:480-482.

Two city employees working for the Boulder, Colo., Open Space Program developed diffuse bilateral pulmonary nodular infiltrates, subsequently identified as being due to Blastomyces dermatitidis. One patient additionally developed skin lesions. Both had received lengthy courses of antibiotics without benefit before the diagnosis was eventually made. Both initially received Amphotericin B followed by months of itraconazole.

One to two weeks earlier, both workers had spent two days excavating abandoned prairie dog tunnels using both hand trowels and powered augers—creating an enormous amount of dust. Fifteen of their co-workers remain asymptomatic and without evidence of infection (serological studies are outstanding).

Even in endemic areas in the Ohio and Mississippi River valleys, the risk for exposure to blastomycosis is small and cases are sporadic. Very few cases have been reported in Colorado. A larger than usual rainfall in the two weeks prior to the dig may have contributed to the growth in topsoil of this dimorphic fungi.

Another unusual case of pneumonitis occurred in a bridge worker in Tennessee who developed cough, fever, and myalgias. The man gradually improved, although the etiologic agent initially eluded diagnosis, despite bronchoscopy and transbronchial biopsy specimens (which suggested but were not diagnostic for sarcoidosis), until a second similar case occurred in a co-worker. Within five days of the first man’s illness, a second worker developed shortness of breath and cough. Despite antibacterial therapy, he developed progressive bilateral nodular infiltrates, subsequently diagnosed as histoplasmosis. Both infections were confirmed by complement fixation and immunodiffusion tests.

The two men were part of a team of seven maintenance workers dispatched to scrub and airbrush a bridge in preparation for painting. None of the workers routinely wore respirators. Within one to two months, three of the remaining five co-workers had evidence of seroconversion to histoplasmosis by complemention fixation and immunodiffusion assays, although they remained asymptomatic. A fourth co-worker had serological results suggesting past infection. Multiple samples of bat guano from the bridge and the soil beneath the bridge were positive for H. capsulatum.

These cases underscore the need for private and public employers to be aware of the potential for these unusual infections, even in areas of low endemicity or in apparently low-risk occupations. Employees should be counseled regarding the importance of appropriate protective clothing, face masks, and, as necessary, respirators. Bridge workers who may be exposed to large amounts of bat guano are at significant risk for occupationally acquired histoplasmosis, al-though documented outbreaks are few. In addition, Jones and colleagues point out that where there is bat guano, there are bats. Consideration should therefore be given to administering prophylactic rabies vaccination to employees who routinely work under bat-infested bridges.

This article also prompted me to question whether homeless camped under bridges are at risk for histoplasmosis, although I could find no evidence in the literature examining this possibility.

Bridge workers developed histoplasmosis after exposure to:

    a. prairie dog tunnels.
    b. dust.
    c. bat guano.
    d. rabies vaccination.