An outbreak of dengue virus at Rio de Janeiro--1986

Dengue virus type 1 has been isolated in Aedes albopictus cell strain, from sera of patients living in the Nova Igua?u county, by Rio de Janeiro. The clinical picture was characterized by fever, headache, retrobulbar pain, backache, pains in the muscles and the joints and prostration. Studies in paired sera confirmed the presence of recent infection by dengue virus type 1. The outbreak reached adjacent areas, including Rio de Janeiro city (May, 1986).     

Effects of shift changes on female workers at a dish factory

This study investigated the effects of working night shifts on social and family life by examining changes in workers' daily life before and after a change in their shifts. Subjects were 40 women aged 27-59 years, working at a dish factory. During the health examination of night workers in autumn of 2000, the subjects were directly interviewed about changes in their lives induced by the shift change. Question parameters consisted of 8 items including 30 sub-items related to social and family life, such as sleep, rest, meals, sports, family time, hobbies, neighborhood association and social activities. The subjects selected one of four response categories: "becoming worse", "no change", "becoming better" and "difficult to determine." With regard to the percentage of "becoming worse", meal-related items ranked high in all of the shift types. "Family time" and "hobbies" showed high percentages in the subjects transferring from day shifts to night shifts, and in those transferring from early-morning shifts to night shifts. "Rest", "sports" and "hobbies" showed high percentages in the subjects transferring from night shifts to midnight shifts. Decreased sleeping hours were confirmed in all of the shift types, while the subjects tended to sleep more soundly. As the workers transfer to shifts at earlier hours, they were obliged to make sacrifices in various aspects of their social and family life. Therefore, much assistance in this regard should be given to them.     

An antibiotic factory caught in action

The synthesis of aromatic polyketides, such as actinorhodin, tetracycline and doxorubicin, begins with the formation of a polyketide chain. In type II polyketide synthases (PKSs), chains are polymerized by the heterodimeric ketosynthase-chain length factor (KS-CLF). Here we present the 2.0-A structure of the actinorhodin KS-CLF, which shows polyketides being elongated inside an amphipathic tunnel approximately 17 A in length at the heterodimer interface. The structure resolves many of the questions about the roles of KS and CLF. Although CLF regulates chain length, it does not have an active site; KS must catalyze both chain initiation and elongation. We provide evidence that the first cyclization of the polyketide occurs within the KS-CLF tunnel. The mechanistic details of this central PKS polymerase could guide biosynthetic chemists in designing new pharmaceuticals and polymers.     

An outbreak of tuberculosis in a group of experimental baboons

A spontaneous outbreak of tuberculosis occurred in an isolated group of 21 baboons being used in an adenovirus type 12 oncogenesis study. Seventeen of the 21 animals were affected. Diagnosis was made by intradermal skin test, chest radiographs, and peripheral blood counts. Confirmation of the diagnosis was by gross and histopathology and culturing of the causative organism. Intradermal tuberculin skin tests were performed simultaneously in the eyelid (intrapalpebral) and abdomen. Fifteen of 16 baboons tested having tuberculosis showed significant reactions in the abdominal skin, whereas only 5 of the 16 had reactions in the eyelid. Infection was respiratory with extensive pathology in the pulmonary viscera. The pathology resembled that of simian tuberculosis, with miliary lesions in the spleen, liver, and in several cases, other abdominal viscera. It was characterized by caseation necrosis and an absence of calcification. Histologically, the lesions resembled the disease described in the great apes rather than the lower monkeys, with numerous Langhans giant cells. The causative organism resembled the human typeMycobacterium tuberculosis morphologically and culturally.These studies were supported in part by USPHS grant numbers GM-FR13252-02 and FR-00278-03.     

An outbreak of hepatitis in marmosets in a zoological collection

12 marmosets of 3 different species died of hepatitis during a period of 5 months. The lesions closely resembled those of virus hepatitis in man but material from these animals and from in-contact marmosets failed to reveal the presence of hepatitis A. This together with certain aspects of the epidemiology of the disease suggests that the outbreak was not caused by a virus of human origin but possibly by a virus indigenous to the marmoset or tamarin.     

An outbreak of trichinellosis in Hungary

In a small village of Hungary, a human trichinellosis outbreak (affecting eight people) occurred in January-February, 2009. In the outbreak investigation (i) Trichinella spiralis larvae were detected in meat products derived from the pigs slaughtered in the backyard of one of the patients (a foxhunter) in December 2008, and in a brown rat captured in the same backyard; (ii) sera of 24 pigs held in 11 yards of the village and that of some dogs of the foxhunter were found Trichinella-positive; (iii) sera of five villagers who could not be infected in the particular outbreak were also found reactive in Trichinella-specific laboratory tests. The followings helped the rise of an outbreak: the geographical position and the presence of empty houses favoured the multiplication of rats; there was no extermination of rats in the previous years; there was no meat inspection; raw meat and improperly processed meat products were tasted at the pig-slaughter; villagers gave tastes to each other. People were informed on the symptoms, the way of transmission, and the possibilities of prevention of trichinellosis by experts. With the help of local authorities, all the properties including the grounds with empty houses were involved in the extermination of rodents.     

Coral disease outbreak at Navassa,a remote Caribbean island

In November 2004, a high prevalence of coral disease was observed at several sites around Navassa, an uninhabited Caribbean island between Haiti and Jamaica. At least fifteen mounding and foliaceous scleractinian species were affected with ‘white disease’ signs. Coral disease incidence was observed to be absent in quantitative surveys in 2002, but in 2004 average prevalence (i.e., % of colonies) of active disease ranged up to 15% and an additional 19% prevalence of colonies with patterns of recent mortality consistent with disease. Large and/or Montastraea spp. colonies were disproportionately affected and the anticipated loss of these large, reef-building colonies will impact coral community structure. One or more potential factors may influence the initiation and persistence of disease outbreak conditions at Navassa including recent hurricane disturbance, regional patterns of increasing disease impact in deep or remote Caribbean reefs, or vectoring of disease by the corallivorous worm, Hermodice carunculata.     

An integral equation model for the control of a smallpox outbreak

An integral equation model of a smallpox epidemic is proposed. The model structures the incidence of infection among the household, the workplace, the wider community and a health-care facility; and incorporates a finite incubation period and plausible infectivity functions. Linearisation of the model is appropriate for small epidemics, and enables analytic expressions to be derived for the basic reproduction number and the size of the epidemic. The effects of control interventions (vaccination, isolation, quarantine and public education) are explored for a smallpox epidemic following an imported case. It is found that the rapid identification and isolation of cases, the quarantine of affected households and a public education campaign to reduce contact would be capable of bringing an epidemic under control. This could be used in conjunction with the vaccination of healthcare workers and contacts. Our results suggest that prior mass vaccination would be an inefficient method of containing an outbreak.