Anders Tegnell

Closure of schools during an influenza pandemic

Summary In response to WHO raising the influenza pandemic alert level from phase five to phase six, health officials around the world are carefully reviewing pandemic mitigation protocols. School closure (also called class dismissal in North America) is a non-pharmaceutical intervention that is commonly suggested for mitigating influenza pandemics. Health officials taking the decision to close schools must weigh the potential health benefits of reducing transmission and thus case numbers against high economic and social costs, difficult ethical issues, and the possible disruption of key services such as health care. Also, if schools are expected to close as a deliberate policy option, or just because of high levels of staff absenteeism, it is important to plan to mitigate the negative features of closure. In this context, there is still debate about if, when, and how school closure policy should be used. In this Review, we take a multidisciplinary and holistic perspective and review the multiple aspects of school closure as a public health policy. Implications for the mitigation of the swine-origin influenza A H1N1 pandemic are also discussed.

The 2000 Tularemia Outbreak: A Case-Control Study of Risk Factors in Disease-Endemic and Emergent Areas, Sweden

A widespread outbreak of tularemia in Sweden in 2000 was investigated in a case-control study in which 270 reported cases of tularemia were compared with 438 controls. The outbreak affected parts of Sweden where tularemia had hitherto been rare, and these “emergent” areas were compared with the disease-endemic areas. Multivariate regression analysis showed mosquito bites to be the main risk factor, with an odds ratio (OR) of 8.8. Other risk factors were owning a cat (OR 2.5) and farm work (OR 3.2). Farming was a risk factor only in the disease-endemic area. Swollen lymph nodes and wound infections were more common in the emergent area, while pneumonia was more common in the disease-endemic area. Mosquito bites appear to be important in transmission of tularemia. The association between cat ownership and disease merits further investigation.

Malaria risk in travelers.

Malaria risk around the world was assessed by using Swedish surveillance data from 1997 to 2003 with an extensive travel database as denominator.

Coagulase-negative staphylococci and sternal infections after cardiac operation

BACKGROUND Coagulase negative staphylococci (CoNS) have been recognized as important pathogens in nosocomial infections, especially in connection with implanted foreign materials. In cardiac operation they are among the most common pathogens isolated from infected sternal wounds. The definition of the infection is very important. In this study we focus on deep postoperative chest infections. METHODS By studying 33 infected patients retrospectively and comparing them to 33 matched uninfected controls, we studied the characteristics and costs of the infections. RESULTS Typical for these infections is the late and insidious onset, and that the infections initially give only minor symptoms such as pain, redness, and serous secretion. We found the following risk factors for infection: number of preoperative days in a hospital, the total length of the operation, and if the patient had undergone an early reoperation due to causes other than infection. This kind of infection more than doubled the hospital costs for the patients affected. CONCLUSIONS Coagulase negative staphylococci are the most important pathogens in deep postoperative infections in this material. They cause infections that are difficult to recognize since they give only discrete symptoms and start well after the patients leave the hospital. The risk factors for patients with CoNS infections are mostly associated with a long exposure to the hospital environment. The treatment is often difficult and costly because of multiresistant bacteria and frequent need for repeated surgical revisions.

Dengue Fever in Travelers to the Tropics, 1998 and 1999

Dengue fever (DF) has become common in western travelers to the tropics. To improve the basis for travel advice, risk factors and dengue manifestations were assessed in 107 Swedish patients for whom DF was diagnosed after return from travel in 1998 and 1999. Patient data were compared with data on a sample of all Swedish travelers to dengue-endemic countries in the same years. Only three of the patients had received pretravel advice concerning DF from their physicians. Hemorrhagic manifestations were common (21 of 74 patients) but caused no deaths. Risk factors for a DF diagnosis were travel to the Malay Peninsula (odds ratio [OR] 4.95; confidence interval [CI] 2.92 to 8.46), age 15–29 years (OR 3.03; CI 1.87 to 4.92), and travel duration >25 days (OR 8.75; CI 4.79 to 16.06). Pretravel advice should be given to all travelers to DF-endemic areas, but young persons traveling to southern and Southeast Asia for >3 weeks (who constituted 31% of the patients in our study) may be more likely to benefit by adhering to it.

Parents' reported reasons for avoiding MMR vaccination : A telephone survey

Objective. During the second half of the 1990s and the first years of the 2000s a declining coverage for MMR vaccination in two-year-olds was observed in Sweden. The aim was to assess reasons for postponement or non-vaccination. Design. A telephone survey using a structured questionnaire on parents’ attitudes regarding their choice to postpone or abstain from vaccinating their child. Setting. The County of Östergötland in Sweden. Subjects. A total of 203 parents of children who had no registered date for MMR vaccination at a Child Health Centre. Main outcome measures. Parental reasons for non-vaccination. Results. In all, 26 of the 203 children had received MMR vaccination but this had not been registered. Of those not vaccinated, 40% of the parents had decided to abstain and 60% to postpone vaccination. Fear of side effects was the most common reason for non-vaccination in both groups. The main source of information was the media followed by the Child Health Centre. Parents with a single child more often postponed vaccination and those who abstained were more likely to have had a discussion with a doctor or nurse about MMR vaccine. Conclusion. Postponers and abstainers may have different reasons for their decision. The role of well-trained healthcare staff in giving advice and an opportunity to discuss MMR vaccination with concerned parents is very important.

A comparative examination of tuberculosis immigration medical screening programs from selected countries with high immigration and low tuberculosis incidence rates

BackgroundTuberculosis (TB) in migrants is an ongoing challenge in several low TB incidence countries since a large proportion of TB in these countries occurs in migrants from high incidence countries. To meet these challenges, several countries utilize TB screening programs. The programs attempt to identify and treat those with active and/or infectious stages of the disease. In addition, screening is used to identify and manage those with latent or inactive disease after arrival. Between nations, considerable variation exists in the methods used in migration-associated TB screening. The present study aimed to compare the TB immigration medical examination requirements in selected countries of high immigration and low TB incidence rates.MethodsDescriptive study of immigration TB screening programsResults16 out of 18 eligible countries responded to the written standardized survey and phone interview. Comparisons in specific areas of TB immigration screening programs included authorities responsible for TB screening, the primary objectives of the TB screening program, the yield of detection of active TB disease, screening details and aspects of follow up for inactive pulmonary TB. No two countries had the same approach to TB screening among migrants. Important differences, common practices, common problems, evidence or lack of evidence for program specifics were noted.ConclusionsIn spite of common goals, there is great diversity in the processes and practices designed to mitigate the impact of migration-associated TB among nations that screen migrants for the disease. The long-term goal in decreasing migration-related introduction of TB from high to low incidence countries remains diminishing the prevalence of the disease in those high incidence locations. In the meantime, existing or planned migration screening programs for TB can be made more efficient and evidenced based. Cooperation among countries doing research in the areas outlined in this study should facilitate the development of improved screening programs.

BICHAT GUIDELINES* FOR THE CLINICAL MANAGEMENT OF HAEMORRHAGIC FEVER VIRUSES AND BIOTERRORISM-RELATED HAEMORRHAGIC FEVER VIRUSES

Haemorrhagic fever viruses (HFVs) are a diverse group of viruses that cause a clinical disease associated with fever and bleeding disorder. HFVs that are associated with a potential biological threat are Ebola and Marburg viruses (Filoviridae), Lassa fever and New World arenaviruses (Machupo, Junin, Guanarito and Sabia viruses) (Arenaviridae), Rift Valley fever (Bunyaviridae) and yellow fever, Omsk haemorrhagic fever, and Kyanasur Forest disease (Flaviviridae). In terms of biological warfare concerning dengue, Crimean-Congo haemorrhagic fever and Hantaviruses, there is not sufficient knowledge to include them as a major biological threat. Dengue virus is the only one of these that cannot be transmitted via aerosol. Crimean-Congo haemorrhagic fever and the agents of haemorrhagic fever with renal syndrome appear difficult to weaponise. Ribavirin is recommended for the treatment and the prophylaxis of the arenaviruses and the bunyaviruses, but is not effective for the other families. All patients must be isolated and receive intensive supportive therapy.

BICHAT GUIDELINES* FOR THE CLINICAL MANAGEMENT OF BRUCELLOSIS AND BIOTERRORISM- RELATED BRUCELLOSIS

Interest in Brucella species as a biological weapon stems from the fact that airborne transmission of the agent is possible. It is highly contagious and enters through mucous membranes such as the conjunctiva, oropharynx, respiratory tract and skin abrasions. It has been estimated that 10-100 organisms only are sufficient to constitute an infectious aerosol dose for humans. Signs and symptoms are similar in patients whatever the route of transmission and are mostly non-specific. Symptoms of patients infected by aerosol are indistinguishable from those of patients infected by other routes. Regimens containing doxycycline plus streptomycin or doxycycline plus rifampin are effective for most forms of brucellosis. Isolation of patients is not necessary. Trimethoprim-sulfamethoxazole and fluoroquinolones also have good results against Brucella, but are associated with high relapse rates when used as monotherapy. The combination of ofloxacin plus rifampicin is associated with good results. Even if there is little evidence to support its utility for post-exposure prophylaxis, doxycycline plus rifampicin is recommended for 3 to 6 weeks.

Bichat guidelines for the clinical management of tularaemia and bioterrorism-related tularaemia.

Francisella tularensis is one of the most infectious pathogenic bacteria known, requiring inoculation or inhalation of as few as 10 organisms to initiate human infection. Inhalational tularaemia following intentional release of a virulent strain of F. tularensis would have great impact and cause high morbidity and mortality. Another route of contamination in a deliberate release could be contamination of water. Seven clinical forms, according to route of inoculation (skin, mucous membranes, gastrointestinal tract, eyes, respiratory tract), dose of the inoculum and virulence of the organism (types A or B) are identified. The pneumonic form of the disease is the most likely form of the disease should this bacterium be used as a bioterrorism agent. Streptomycin and gentamicin are currently considered the treatment of choice for tularemia. Quinolone is an effective alternative drug. No isolation measures for patients with pneumonia are necessary. Streptomycin, gentamicin, doxycycline or ciprofloxacin are recommended for post-exposure prophylaxis.