The burden of foodborne disease is not well defined in many countries or regions or on a global level. The World Health Organization (WHO), in conjunction with other national public health agencies, is coordinating a number of international activities designed to assist countries in the strengthening of disease surveillance and to determine the burden of acute gastroenteritis. These data can then be used to estimate the following situations: (1) the burden associated with acute gastroenteritis of foodborne origin, (2) the burden caused by specific pathogens commonly transmitted by food, and (3) the burden caused by specific foods or food groups. Many of the scientists collaborating with the WHO on these activities have been involved in quantifying the burden of acute gastroenteritis on a national basis. This article reviews these key national studies and the international efforts that are providing the necessary information and technical resources to derive national, regional, and global burden of disease estimates.

Q fever has emerged as an important human and veterinary public health problem in the Netherlands with major outbreaks in three consecutive years. Goat farms are probably the prime source from which Coxiella burnetii have spread throughout the environment, infecting people living in the vicinity. Coxiella burnetii infection not only spilled over from animal husbandry to humans but could also have spread to neighbouring wildlife and pets forming novel reservoirs and consequently posing another and lingering threat to humans, companion animals and livestock. In these cases, transmission routes other than airborne spread of contaminated aerosols may become significant. Therefore, the role of ticks in the transmission of Coxiella burnetii in the current situation was investigated. A total of 1891 questing Ixodes ricinus ticks and 1086 ticks feeding on pets, wildlife and livestock were tested by a recently developed multiplex Q-PCR. All ticks were negative, except for a few ticks feeding on a herd of recently vaccinated sheep. Coxiella-positive ticks were not detected after resampling this particular herd three months later. Based on these data we conclude that the current risk of acquiring Q fever from questing ticks in the Netherlands is negligible. However, for future risk assessments, it might be relevant to sample more ticks in the vicinity of previously C. burnetii infected goat farms and to assess whether C. burnetii can be transmitted transovarially and transstadially in I. ricinus ticks.

The close genetic relationship of human and animal strains of norovirus has raised the possibility of transmission of noroviruses from animals to humans and may explain the emergence of certain norovirus strains. To assess if exposure to bovine noroviruses (NoV) might result in infection in humans, an enzyme immunoassay (EIA) was designed and validated in order to detect antibodies against bovine norovirus. This and two other EIAs were used to test sera from 210 veterinarians and 630 matched population controls for IgG and IgA antibodies to recombinant capsid protein of bovine NoV (rBoV), Norwalk virus (rNV), and Lordsdale virus (rLDV). Of 840 participants, IgG reactivity to rBoV was found in 185 (22%), to rNV in 638 (76%) and to rLDV in 760 (90%). IgG reactivity to rBoV was more common in veterinarians (58/210: 28%) than in controls (127/630: 20% [P = 0.03]). IgA reactivity to rBoV was similar in both veterinarians and controls. Cross-reactivity of IgA and IgG antibodies to rBoV and rNV was seen, but 26% of all specimens positive rBoV antibodies showed high IgG reactivity to rBoV but low reactivity to rNV, suggesting a specific response to bovine antigen. No evidence of overall cross-reactivity of antibodies to rBoV and rLDV was seen. Among veterinarians, youth spent on farm (Odds Ratio [OR] = 1.8) and membership of the bovine practitioners' society (OR = 2.7) were significantly associated with IgG seroreactivity to rBoV. These data indicate that bovine strains of NoV may infect humans though less frequently than human strains.

Objectives: To study the association of serovars of Chlamydia trachomatis with clinical manifestations of genital tract infection and socio-demographic characteristics. Methods: In 1986-88 the C trachomatis isolates from 159 heterosexual men and 116 women attending a sexually transmitted disease (STD) clinic were collected and typed accordingly. A medical history was recorded, a physical examination took place and samples were taken for laboratory diagnostics.Results: Serovars E, F and D were the most common for both men (75%) and women (67%). Men infected with serovars of the C-complex had more often a history of STD (p = 0 06). The opposite was demonstrated in women (p = 0.07). In addition, women younger than 18 years at first intercourse were more often infected with C-complex serovars (p = 0.05). For men, the serovars F/G less often produced symptoms of urethral discharge (p = 0-01) than the serovars of the B-complex and C-complex and were less often associated with the presence of 10 or more leukocytes in a Gram-stained smear (p = 0.04). Conclusions: In this study, infections with serovars F and G caused less obvious symptoms and signs of inflammation in men; in women no differences were found in the clinical manifestation of infections with different serovars. (Genitourin Med 1996;72:261-265)

Objective: To evaluate the prevalence and epidemiology of penicillinase producing Neisseria gonorrhoeae (PPNG) and tetracycline resistant Ngonorrhoeae (TRNG) (Genitourin Med 1997;73:510-517)