The burden of hepatitis C in Sweden: a national study of inpatient care

The spread of hepatitis C virus (HCV) in Sweden in the 1970s indicated that serious liver complications (SLC) would increase in the 2000s. The aim of this study was to analyse the burden of HCV-associated inpatient care in Sweden, to demonstrate the changes over time and to compare the findings with a noninfected population. The HCV-cohort (n: 43,000) was identified from the national surveillance database 1990-2006, and then linked to national registers to produce an age-, sex-, and region-matched noninfected comparison population (n: 215,000) and to obtain information on demographics, cancers, inpatient care and prescriptions. Cox regression was used to estimate the likelihood (hazard ratios) for admission to hospital in the HCV compared with the noninfected cohort. The hazard ratios were 4.03 (95% CI: 3.98-4.08) for all care, 77.52 (71.02-84.60) for liver-related care and 40.74 (30.58-54.27) for liver cancer care. The admission rate in the HCV-cohort compared with the noninfected cohort, the rate ratio (age- and sex-adjusted) for all inpatient care was 5.91 (95% CI: 5.87-5.94), and the rate ratio for liver-related care was 70.05 (66.06-74.28). In the HCV-cohort, 45% of all episodes were for psychiatric, mostly drug-related, care. Inpatient care for SLC increased in the 2000s. To conclude, drug-related care was common in the HCV-infected cohort, the demand for liver-related care was very high, and SLC increased notably in the 2000s, indicating that the burden of inpatient care from serious liver disease in HCV-infected individuals in Sweden is an increasing problem.

Validity of routine surveillance data: a case study on Swedish notifications of methicillin-resistant Staphylococcus aureus

Surveillance of communicable diseases is a public health corner stone. Routine notification data on communicable diseases are used as a basis for public health action as well as for policy making. While there are agreed standards for evaluating the performance of surveillance systems, it is rarely possible to analyse the validity of the data entered into these systems. In this study we compared data on all Swedish cases of methicillin-resistant Staphylococcus aureus (MRSA) routinely notified between 2000 and 2003 with follow-up information collected for each of these cases as part of a public health project. The variables Reason for testing (clinical sample, contact tracing, screening of risk group), Clinical presentation (disease, colonisation), Transmission setting (healthcare-acquired, community-acquired), Country of acquisition (Sweden, abroad) and Risk-occupation (yes, no) were analysed for sensitivity, positive predictive value and completeness of answers. The sensitivity varied between 23% and 83%, the positive predictive values were generally higher (55% to 97%), while missing answers varied from 11% to 59%. The proportion of community-acquired cases was markedly higher when excluding either cases of MRSA colonisation or cases found through public health-initiated activities (contact tracing or screening of risk groups). We conclude that the quality of routine surveillance data may be inadequate for in-depth epidemiological analyses. This should be taken into account when interpreting routine surveillance figures. Whether or not the case definition includes cases of MRSA colonisation may have a significant impact on population-wide estimates of MRSA occurrence.

Rabies – a recurrent danger to European countries from dogs introduced from endemic countries

Although vaccine-preventable, rabies remains a worldwide-occurring disease of major public health concern. Globally, rabies is responsible for about 55,000 human deaths per year, mainly in Asia and Africa, and 30-50% of the cases are in children, most often following an infection transmitted through the bite of a rabid dog.

Eurosurveillance moves on…

From this issue of Eurosurveillance, the two previous electronic releases (weekly and monthly) of the journal have been merged into one. The new Eurosurveillance is published every Thursday, with rapid updates on major public health events and news items alongside longer scientific articles and reviews. At the same time we are updating our editorial policy (http://www.eurosurveillance.org/editorial_policy/index.asp) and reviewing the types of articles (http://www.eurosurveillance.org/authors/index.asp) to better reflect our commitment to covering all aspects of epidemiology, prevention and control of communicable diseases from a European perspective.

New Health Communication Unit in ECDC

From 1 May, a new Health Communication Unit (HCU) has been established in the European Centre for Disease Prevention and Control (ECDC).

Wound infections due to Vibrio cholerae in Sweden after swimming in the Baltic Sea, summer 2006

In recent weeks, three people in Blekinge County in southeast Sweden were reported to have developed mild to severe wound

An evaluation and comparison of three commonly used statistical models for automatic detection of outbreaks in epidemiological data of communicable diseases

We evaluated three established statistical models for automated 'early warnings' of disease outbreaks; counted data Poisson CuSums (used in New Zealand), the England and Wales model (used in England and Wales) and SPOTv2 (used in Australia). In the evaluation we used national Swedish notification data from 1992 to 2003 on campylobacteriosis, hepatitis A and tularemia. The average sensitivity and positive predictive value for CuSums were 71 and 53%, for the England and Wales model 87 and 82% and for SPOTv2 95 and 49% respectively. The England and Wales model and the SPOTv2 model were superior to CuSums in our setting. Although, it was more difficult to rank the former two, we recommend the SPOTv2 model over the England and Wales model, mainly because of a better sensitivity. However, the impact of previous outbreaks on baseline levels was less in the England and Wales model. The CuSums model did not adjust for previous outbreaks.

Human salmonellosis in travellers is highly correlated to the prevalence of salmonella in laying hen flocks

Comparison of the recent European Food Safety Authority (EFSA) report on the prevalence of salmonella in laying hen flocks

SmiNet-2: Description of an internet-based surveillance system for communicable diseases in Sweden

Electronic systems for communicable diseases surveillance enhance quality by simplifying reporting, improving completeness, and increasing timeliness. In this article we outline the ideas and technologies behind SmiNet-2, a new comprehensive regional/national system for communicable disease surveillance in Sweden. The system allows for reporting from physicians (web form) and laboratories (direct from lab data system) over the internet. Using a unique personal identification number, SmiNet-2 automatically merges clinical and laboratory notifications to case records. Privileged users, at national and county level, work against a common central server containing all notifications and case records. In addition, SmiNet-2 has separate county servers with tools for outbreak investigations, contact tracing and case management. SmiNet-2 was first used in September 2004. Individual counties receive up to 90% of all notifications electronically. In its first year, SmiNet-2 received 54 980 clinical notifications and 32 765 laboratory notifications, which generated 58 891 case records. Since most clinicians in Sweden have easy access to the internet, a general web-based reporting has been feasible, and it is anticipated that within a few years all reporting to SmiNet-2 will be over the internet. In this context, some of the major advantages of SmiNet-2 when compared with other systems are timeliness in the dataflow (up to national level), the full integration of clinical and laboratory notifications, and the capability to handle more than 50 diseases with tailor-made notification forms within one single system.

SmiNet-2: Description of an internet-based surveillance system for communicable diseases in Sweden

Electronic systems for communicable diseases surveillance enhance quality by simplifying reporting, improving completeness, and increasing timeliness. In this article we outline the ideas and technologies behind SmiNet-2, a new comprehensive regional/national system for communicable disease surveillance in Sweden. The system allows for reporting from physicians (web form) and laboratories (direct from lab data system) over the internet. Using a unique personal identification number, SmiNet-2 automatically merges clinical and laboratory notifications to case records. Privileged users, at national and county level, work against a common central server containing all notifications and case records. In addition, SmiNet-2 has separate county servers with tools for outbreak investigations, contact tracing and case management. SmiNet-2 was first used in September 2004. Individual counties receive up to 90% of all notifications electronically. In its first year, SmiNet-2 received 54 980 clinical notifications and 32,765 laboratory notifications, which generated 58,891 case records. Since most clinicians in Sweden have easy access to the internet, a general web-based reporting has been feasible, and it is anticipated that within a few years all reporting to SmiNet-2 will be over the internet. In this context, some of the major advantages of SmiNet-2 when compared with other systems are timeliness in the dataflow (up to national level), the full integration of clinical and laboratory notifications, and the capability to handle more than 50 diseases with tailor-made notification forms within one single system.

'Did you have flu last week?’ A telephone survey to estimate a point prevalence of influenza in the Swedish population

Sentinel surveillance usually underestimates the true burden of influenza in a population, as individuals must present to medical establishments to be included in the surveillance system. We carried out a telephone survey to estimate the national burden of influenza in the Swedish population for one week during the 2004/05 influenza season. Fixed-line telephone numbers were randomly sampled and households interviewed concerning influenza illness between 14-20 February 2005 (Week 7 of 2005). Questions regarding seasonal influenza vaccination status, symptoms and the impact of illness on daily life were also included. A self-defined influenza prevalence of 7.7% in week 7 of 2005 was estimated. On applying a case definition of ‘cough and fever and muscle pain’ for influenza like illness, the prevalence decreased to 3.6%. The survey provided insight into the burden of illness in the population further to that estimated through the sentinel surveillance system.

Sensitivity of the Swedish statutory surveillance system for communicable diseases 1998-2002, assessed by the capture-recapture method

To assess the sensitivity of the Swedish surveillance system, four notifiable communicable diseases in Sweden were examined during 1998-2002 with the two-sources capture-recapture method, based on parallel clinical and laboratory notifications. The sensitivity (proportion of diagnosed diseases actually being notified) was highest for salmonellosis (99.9%), followed by meningococcal infection (98.7%), and tularaemia (98.5%). For penicillin-resistant pneumococci, introduced as a notifiable disease in 1996, the overall sensitivity was 93.4%--increasing from 86.5% in 1998 to 98.5% in 2002. The system benefited from parallel reporting, with a sensitivity of clinical and laboratory notifications alone (all diseases combined) of 91.6% and 95.9% respectively. The sensitivity of both clinical and laboratory notifications was markedly higher in counties using the national electronic reporting system, SmiNet. Thus, sensitivity was higher for diseases with a long tradition of reporting, and there is a run-in period after a new disease becomes notifiable.

Travel-associated non-typhoidal salmonellosis: geographical and seasonal differences and serotype distribution

The Swedish database on notifiable communicable diseases was used to identify 24 803 cases of travel-associated non-typhoidal salmonellosis from the period 1997-2003. Serotype data were available for 24 358 (98.2%) of these cases, which were compared with a data set from the same period of 16 255 randomly selected Swedish residents with a history of recent overnight travel outside Sweden. The highest risk of disease was seen in travellers returning from East Africa (471/100 000 travellers; 95% CI 294-755), or the Indian subcontinent (474/100 000; 95% CI 330-681). Children aged 0-6 years were at higher risk than travellers of other ages (OR 2.4; 95% CI 2.1-2.8). Some distinct seasonal patterns could be distinguished, with highest (adjusted) risk in December in East Asia, and in August in Europe. Marked geographical differences in serotype distribution were noted. Salmonella Enteritidis was especially dominant in Europe, but was much less common in Africa, Asia and America, where the variety of circulating serotypes was greater. Overall, the two data sets provided important information on travel risks which are also likely to apply to travellers from other western countries.

Travellers returning to Sweden as sentinels for comparative disease incidence in other European countries, campylobacter and giardia infection as examples

Comparable figures on disease incidence between countries are difficult to attain. We therefore compared risk of infection for Swedes going to other European countries. We took as the numerator the number of imported cases from European countries of campylobacter and giardia infection in the national Swedish surveillance database, and as the denominator, the number of visitors to each country from a commercial database on foreign travel. Risk of infection in tourists was also compared to national incidence figures for a selection of countries.

Clinical spectrum and transmission characteristics of infection with Norwalk-like virus: findings from a large community outbreak in Sweden

A large foodborne outbreak caused by Norwalk-like virus (NLV) among children and staff at 30 day care centers provided an opportunity to study symptomatology and attack rates among patients in different age groups, as well as secondary transmission rates in centers and households. A retrospective cohort study of 775 subjects from 13 randomly chosen centers was performed. Diarrhea was more common in adults than in children (P=.001), whereas the reverse was noted with regard to vomiting (P=.003). The primary attack rate was 27% (142 of 524 subjects): 54% of adults versus 19% of children (P<.001). The mean incubation time for foodborne cases of infection was 34 hours. The secondary attack rate was 17%. Risk factors for spread into households were the primary case being a child (relative risk [RR], 3.8; 95% confidence interval [CI], 1.9-7.6) and vomiting (RR, 2.4; 95% CI, 1.0-5.5). The incubation time for person-to-person transmission was approximated by a mean serial interval of 52 hours. This is the first reported outbreak of NLV infection in which secondary transmission into households by individuals has been studied.

A whirlpool associated outbreak of Pontiac fever at a hotel in Northern Sweden

In April 1999, an outbreak of Pontiac fever occurred at a hotel in Northern Sweden. A retrospective cohort study to find the source and define the extent of the outbreak was carried out among 530 Swedish and Norwegian guests. Twenty-nine epidemiological cases (8% of 378 responders) aged 21-57 years were identified. Antibodies against Legionella micdadei were detected in 17 of 27 tested cases and 3 other symptomatic persons. Visiting the whirlpool area was identified as the sole risk factor (RR 86; 95% CI 21-352) and infected cases were confined to visitors to this area over three successive days. The attack rate was 71% (27/38) and 24 cases (83%) used the whirlpool. Environmental sampling was negative for Legionella sp. But epidemiological investigation strongly suggests that the whirlpool was the source of the outbreak. The possibility of serious legionella infections underlines the importance of strict maintenance practices to maintain hygiene of whirlpools.

Epidemiology of pneumococcal infections in Swedish children

OBJECTIVE

This paper provides an overview of pneumococcal infections in Swedish children.

METHOD

Data supplied by the Swedish Institute for Infectious Disease Control (SMI) provided information on invasive pneumococcal isolates and on isolates with reduced susceptibility to penicillin. Disease burden was estimated from data collected in northern Stockholm and Malmöhus County.

RESULTS

Only 3-6% of the total number of invasive pneumococcal isolates came from children 0-15 years of age. Predominant serotypes in descending frequency were 7, 6, 14, and 23. Strains from all sources with reduced sensitivity to penicillin (MIC > or = 0.5 mg/l) were found in 3% of children and varied between 0.2% and 11%, with the highest value found in Southern Sweden (predominating strains were 9, 19, 15, 6, and 23). A 10-year review of all cases of meningitis in Northern Stockholm reflected an incidence of 10/100,000 (0-2 years) or 5.8/100,000 (0-5 years), with severe sequelae occurring in 20% of children. This information can be used to predict an annual incidence of 30 cases of meningitis in Sweden.

CONCLUSION

The large proportion of serotype 7 among invasive isolates is distressing since this serotype is not represented in the present 7- and 9-valent protein-conjugated vaccines under development. However, the heptavalent vaccine, including serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F would (at a serotype level) provide coverage against 83% of the resistant isolates in Southern Sweden.

Frequency of penicillin-resistant pneumococci in children is correlated to community utilization of antibiotics

OBJECTIVE

To study the impact of the utilization of antibiotics in children at the population level on the frequency of penicillin-nonsusceptible pneumococci (PNSP).

DESIGN

Children ages 0 to 6 years with a nasopharyngeal culture of PNSP were registered on place of residency in the 20 municipalities of the former Malmöhus County (since 1998 a part of Skåne County). Where possible the total number of nasopharyngeal cultures with growth of pneumococci was registered as well. All antibiotic prescriptions for 0- to 6-year-old children were analyzed in the 20 municipalities.

MAIN OUTCOME MEASURES

Correlation between the utilization of antibiotics and the frequency of PNSP in children at the municipality level.

RESULTS

The proportion of PNSP among all isolates of pneumococci from nasopharyngeal cultures varied between 0 and 49.5%. The antibiotic utilization in children varied among the 20 neighboring municipalities from 8.5 to 19.7 defined daily doses per 1000 children per day. The municipalities with high total utilization also had more frequent use of macrolides and broad spectrum antibiotics. The was a significant correlation between antibiotic use and the proportion of PNSP (correlation coefficient, 0.96; P = 0.002), and the correlation coefficients for trimethoprim-sulfamethoxazole, amoxicillins, macrolides and cephalosporins were significant at the 0.001 level. There was no significant correlation between the use of penicillin V and the frequency of PNSP. CONCLUSIONS. There was a significant correlation between the frequency of PNSP and the utilization of antibiotics in children at the population level.

[Tuberculosis a threat again. Multiresistance in the Baltic States and in Russia; Nordic countries initiate cooperation to prevent transmission]

The incidence of tuberculosis (TB) has more than doubled in the Baltic States during the last decade and is now 10-15 times higher than in Sweden. It is also a serious problem in Russia. Strains resistant to one or several of the anti-tuberculous drugs are common as is multi-drug resistance (MDR), i.e. strains resistant to the two most effective drugs rifampicin and isoniazid. MDR-TB is very difficult to treat; the mortality rate is high. Initiatives have been taken in the Nordic countries in order to help to control and improve the situation by way of supportive measures.

Penicillin-resistant pneumococci in southern Sweden, 1993-1997

In Malmöhus County, Southern Sweden, the frequency of penicillin-resistant pneumococci in nasopharyngeal specimens of outpatients with respiratory tract infections increased from 3.1% in 1993 to 7.6% in 1995, and was thereafter rather stable. Over the period, 82-85% of the patients with penicillin-resistant strains were children 0-6 years of age. Ten groups/types constituted 96-100% of the penicillin-resistant isolates. Grouping/typing of 200 consecutive isolates in October and November each year indicated that the distribution of groups/types amongst patients with respiratory tract infections was rather constant over the period. The frequency of penicillin-resistant pneumococci of groups/types 6, 14, and 19 roughly corresponded to the occurrence of these groups/types amongst the consecutive isolates. Other groups/types 9, 15, 21, and 23 either showed a pronounced increase or decrease, which could not be related to the prevalence of these groups/types among the consecutive isolates or degree of antibiotic resistance. Penicillin-resistant group 9, introduced in the area in 1993, consisted of one single clone, 9V. The stabilized level of penicillin resistance since 1995 may be related to the preventive measures implemented in the area, including day-care interventions, and measures to reduce the prescription rate of antibiotics to outpatients with respiratory tract infections.

Limiting the spread of penicillin-resistant Streptococcus pneumoniae: experiences from the South Swedish Pneumococcal Intervention Project

In an attempt to limit the spread of penicillin-resistant pneumococci (PRP), an intervention project was initiated in the Malmöhus County, southern Sweden in January 1995. The ongoing project combines traditional communicable disease control measures and actions aiming at reducing antibiotics consumption. All patients in the county with a nasopharyngeal culture positive for PRP with MIC of Penicillin G > or =0.5 mg/L are followed with nasopharyngeal cultures until PRP-negative. Nasopharyngeal cultures are obtained from family members and close contacts of the index cases. Preschool children carrying PRP are denied attendance at group day-care. From January 1995 to March 1997, 1,038 PRP-carriers (429 index cases and 609 contact cases) were identified. Children aged 1-6 years dominated (83%). Antibiotics sales decreased during the study period, and epidemiologic data indicate that the intervention may have limited the dissemination of PRP in the county, but further evaluation is needed.

Introduction and clonal spread of penicillin- and trimethoprim/sulfamethoxazole-resistant Streptococcus pneumoniae, serotype 9V, in southern Sweden

As part of an intervention project, all patients in Malmöhus county with a culture positive for penicillin-resistant pneumococci, MIC > or =0.5 mg/L (PRP), have been registered since January 1995. Nasopharyngeal specimens were obtained from family members and close contacts of identified carriers. Children were denied attendance at regular day-care until PRP-negative. In 1995 and 1996, PRP were isolated from 882 individuals, 364 of whom had clinical infection and the remaining of whom were asymptomatic carriers. In 49%, the PRP were of serogroup 9, with MIC of penicillin 0.5-2.0 mg/L and resistance to trimethoprim/sulfamethoxazole. Further analyses with serotyping and genetic fingerprinting suggested strongly that most of the isolates belonged to a single serotype 9V clone. Month by month, an apparently continuous spread appeared from one municipality to a neighboring one. In most communities, the serotype 9V PRP appeared and disappeared within a few months. The active procedures of the intervention project may have limited the spread of the clone in the county.

[Reduced frequency of resistant pneumococci in Southern Sweden. Community based disease control projects to minimize antibiotic resistance]

In an attempt to limit the spread of penicillin non-susceptible pneumococci (PNSP) in southern Sweden, early in 1995 an intervention project was launched, using a combination of traditional communicable disease control measures and actions aimed at reducing antibiotics consumption. Patients carrying PNSP (penicillin G MIC (0.5 mg/L) are monitored with nasopharyngeal cultures until PNSP-negative. Pre-school children are kept home from group day-care facilities. Previous antibiotic consumption was identified as a risk factor for PNSP carriage. Antibiotics sales decreased during the study period, and epidemiological findings suggest the dissemination of PNSP in the area to have been reduced by the intervention project.

Previous respiratory tract infections and antibiotic consumption in children with long- and short-term carriage of penicillin-resistant Streptococcus pneumoniae

Previous respiratory tract infections (RTI) and antibiotics consumption as possible risk factors for extended duration of PRP carriage were investigated in 24 children (cases) with previous carriage of penicillin-resistant pneumococci (PRP) for a duration exceeding 120 days (median 168 days) and a control group of 53 children with a duration of PRP carriage less than 90 days (median 21 days). The cases had experienced 0.99 episodes of acute otitis media (AOM) per life-year compared to 0.79 episodes in the controls (P = 0.32). For antibiotic-treated RTI other than AOM, the corresponding numbers were 0.49 and 0.29 episodes per life-year, respectively (P = 0.01). No differences in antibiotic consumption in the 3 months preceding the carriage, nor during the carriage period were noted. Other factors than impaired host defence to respiratory tract pathogens or antibiotics consumption seem to be more important in determining the duration of PRP carriage.

Previous antibiotic consumption and other risk factors for carriage of penicillin-resistant Streptococcus pneumoniae in children

As part of the South Swedish Pneumococcal Intervention Project, aimed at reducing the spread of penicillin-resistant pneumococci with MICs for penicillin G > or =0.5 mg/l (PRP), all patients in Malmöhus county, southern Sweden, with a culture positive for PRP were followed up by means of repeated nasopharyngeal cultures until PRP-negative. If a child carrying PRP attended a day-care centre, nasopharyngeal cultures were obtained from the other children and staff. All children screened for PRP carriage in 30 day-care centres with an identified index case were included in the analysis, and several outcome variables (antibiotic consumption during the preceding 6 months, previous health and social situation) were assessed in relation to the end-point PRP carriage. Of 1036 children, 128 were found to be PRP carriers and 908 were PRP non-carriers. The PRP carriers had higher antibiotic consumption, were younger and were more often of male sex than the non-carriers (P<0.05). Consumption of antibiotics during the preceding 6 months was noted in 53% of carriers and 45% of non-carriers (relative risk 1.20, 95% confidence interval 1.01-1.43). When adjusting for age, gender and day-care centre attendance, recent consumption of cotrimoxazole (trimethoprim/sulfamethoxazole) emerged as an independent risk factor for PRP-carriage (relative risk 3.48, 95% confidence interval 1.10-11.07). The PRP-carriage rate in three day-care centres with high cotrimoxazole consumption was significantly higher (24%) than in the other day-care centres (10%) (P<0.005). The results indicate that measures aimed at reducing consumption of antibiotics in general, and cotrimoxazole in particular, may decrease the incidence of penicillin resistance, but such measures are, by themselves, probably not sufficient to halt the spread.

Bacteraemic pneumococcal infections in Southern Sweden 1981-96: trends in incidence, mortality, age-distribution, serogroups and penicillin-resistance

In a survey of pneumococcal blood isolates from patients in Southern Sweden, 560 isolates were found between 1981 and 1996. Between these years, the incidence of pneumococcal bacteraemia increased from 5.2 to 15.2/100,000/y. The eight most common serogroups/types (14, 7, 9, 6, 23, 3, 4 and 19) accounted for > 75% of the isolates, and 96.4% of the isolates were of serogroups/types represented in the present vaccine. A male preponderance (1.17:1) was noted, and the men were younger than the women (mean 57 vs 63 y of age; p < 0.05). The overall case-fatality rate during the period was 19%. Seven isolates with reduced susceptibility to penicillin were noted, all from 1991 to 1996. The increasing incidence of pneumococcal bacteraemia could not be explained by any of the following factors; age or sex of the patients, changes in prevailing serogroups/types, variations in vaccine use, emergence of penicillin-resistance, more liberal indications for blood cultures or improved culture methods.

Eradication of penicillin-resistant pneumococci in the nasopharynx with antibiotic combinations including rifampicin: experiences from the South Swedish Pneumococcal Intervention Project

39 children with prolonged nasopharyngeal carriage (48-328 days) of intermediately to highly penicillin-resistant pneumococci (PRP) were treated for 7 days with rifampicin in combination with amoxicillin (n = 18) erythromycin (n = 17) or clindamycin (n = 4), according to resistance pattern. In all children, except for 1 carrying a rifampicin-resistant strain, control cultures from the nasopharynx 1-2 weeks after the last antibiotic dosage, yielded no growth of PRP. In 2 brothers, PRP with the same serogroup and resistance pattern were found in nasopharynx 10 weeks after the antibiotic treatment. These preliminary findings indicate that antibiotic regimens including rifampicin are effective in eradicating nasopharyngeal carriage, but reappearance of the same strain may occur after several weeks. Such treatments should be given with caution due to the risk of selecting rifampicin-resistant strains. Further controlled studies are needed to determine the optimal combination of antibiotics and appropriate duration of therapy.

Immunoglobulin deficiencies and impaired immune response to polysaccharide antigens in adult patients with recurrent community-acquired pneumonia

The frequency of humoral immunodeficiencies was analysed in 39 patients with a history of recurrent (> or = 3) episodes of community-acquired pneumonia. Total immunoglobulin levels and/or IgG subclass levels were low in 14 patients (36%), including eight patients with IgG or IgG2 deficiency. The specific antibody activity to pneumococcal capsular polysaccharides (serotypes 3, 6A, 19F, and 23F) and to phosphorylcholine was low in the IgG/IgG2-deficient patients compared to 36 healthy controls, and they also responded poorly to vaccination with a 23-valent pneumococcal capsular polysaccharide vaccine. The remaining 25 patients, with normal immunoglobulin and IgG subclass levels, had specific anti-pneumococcal antibody levels comparable to the healthy controls, and all but 3 responded to vaccination. We conclude that immunoglobulin deficiencies and the inability to respond to polysaccharide antigens are common risk factors for recurrent pneumonia in adult patients. Immunoglobulin levels (including IgG subclasses) and antibody response to polysaccharide antigens should be investigated in these patients.

Duration of nasopharyngeal carriage of penicillin-resistant Streptococcus pneumoniae: experiences from the South Swedish Pneumococcal Intervention Project

As a part of an intervention project, all detected carriers of penicillin-resistant pneumococci (PRP) (MIC, > or = 0.5 mg/L) in Malmöhus County, southern Sweden, were followed by means of weekly nasopharyngeal cultures. The median duration of carriage in 678 individuals was 19 days (range, 3-267 days). The duration of carriage was longest in children < 1 year old (median, 30 days) and shortest in adults > 18 years old (median, 14 days). Index cases, whose cultures were performed during an acute infection, were carriers for a mean of 10 days longer than asymptomatic contact cases (P < .05). The PRP spontaneously disappeared from the nasopharynx within 4 weeks in 68%, within 8 weeks in 87%, and within 12 weeks in 94% of the individuals. Other significant risk factors for prolonged carriage were the occurrence of > 6 episodes of acute otitis media (AOM) or first episode of AOM before the age of 1 year (P < .01), the carriage of PRP by other family members (P < .05), and the obtainment of a first positive culture during the winter months (P < .05).

Impaired antibody response to pneumococcal capsular polysaccharides and phosphorylcholine in adult patients with a history of bacteremic pneumococcal infection

The serum antibody response after immunization with a pneumococcal vaccine was analyzed in 46 patients with a history of bacteremic pneumococcal infection and in 36 healthy controls. Seven patients with IgG/IgG2 deficiencies had significantly lower preimmunization and postimmunization levels of antibody to pneumococcal capsular polysaccharides (serotypes 3, 6A, 19F, and 23F) and phosphorylcholine than did the control subjects, while the patients with normal IgG/IgG2 levels did not have a deficient antibody response. For the whole patient group, postimmunization levels of antibody against the serotypes that caused the bacteremias were lower than the levels against other tested serotypes (P < .05). Ten patients vs. one control subject were unable to mount a postimmunization antibody response to the four tested serotypes (P < .05). Six of these 10 nonresponding patients had low IgG/IgG2 levels. The results demonstrate that a poor antibody response to vaccination with capsular polysaccharides, often associated with IgG/IgG2 deficiency, is common in patients with a history of bacteremic pneumococcal infections.

Hepatitis B virus strains in Thailand: genomic variants in chronic carriers

Genetic heterogeneity of the hepatitis B virus (HBV) has been shown to influence the serological pattern and clinical picture in HBV infection. Thailand has a high transmission rate of HBV, but the molecular epidemiology of HBV strains circulating in this region was hitherto unknown. In this study, the HBV strains from 34 Thai HBsAg-positive patients were investigated. In a proportion of these samples, an antigenically important region of the S gene (n = 18), and the pre-S2 and precore genes (n = 15) were sequenced after PCR amplification. Four strains had in-frame deletions of an upstream region of the pre-S2 gene, with all deletions ending at the same nucleotide. In one of three anti-HBe positive strains without a translational stop at codon 28 of the precore gene, there was a one nucleotide insertion in the precore gene. This insertion would cause a frame shift and result in a nonsense protein being expressed, thus providing one explanation for the lack of HBeAg in this patient. Several rare or unique amino acid changes in the region between residues 120 and 161 of the S protein were found. Glycine 145 was changed to alanine in one strain, and this position showed an apparent mixture of glycine and arginine in another. In total, 10 strains displayed unexpected changes that were not related to the normal variability between subtypes or genetic subgroups. It is concluded that there is considerable heterogeneity in HBV strains in Thailand and that this could have clinical and epidemiological importance in a region with high HBV transmission rates.

Complement analysis in adult patients with a history of bacteremic pneumococcal infections or recurrent pneumonia

Complement deficiencies are known to be associated with increased susceptibility to bacterial infections. In the present study we investigated 80 patients with either a history of pneumococcal bacteremic infection, or recurrent pneumonia, or both. Hemolytic screening tests for complement deficiency were performed and serum concentrations of C1q, C1s, C2, C3, C4, C4 isotypes, factor B, factor D, and properdin were determined. Complete deficiencies of single complement proteins were not found. 10 patients (12%) had a C4 isotype deficiency, but the frequency of homozygous C4A and C4B deficiency was not significantly increased. Seven patients (9%) had hypocomplementemia with low concentrations of at least 2 complement proteins. One of these patients had profound depletion of classical pathway components and findings suggesting acquired C1 esterase inhibitor deficiency. 16 patients (20%) had minor complement aberrations. A majority of the patients with hypocomplementemia suffered from other conditions associated with pneumococcal infections. However, impaired complement function could be a significant predisposing factor in some patients with invasive pneumococcal infections or recurrent pneumonia.

Analysis of immunoglobulin isotype levels in acute pneumococcal bacteremia and in convalescence

In 48 patients with a history of a pneumococcal bacteremia, serum taken during the acute phase of the infection was analyzed for IgG and IgG subclasses. Once the patients were free of infection, a serum sample was analyzed for IgG, IgG subclasses, IgA and IgM. In an additional 20 patients, it was only possible to analyze serum from the infection-free phase. Seventeen of 48 (35%) patients had reduced levels of total IgG or of one or more of the IgG subclasses during acute disease. Of the 48 patients in whom both acute phase and infection-free phase serum were analyzed, values of IgG (p < 0.001), IgG1 (p < 0.001), IgG2 (p < 0.001), IgG3 (p < 0.01) and IgG4 (p < 0.01) were decreased during the acute infection. During the infection-free phase, 12 of 68 (18%) patients had a recognizable immunodeficiency, including two patients with common variable immunodeficiency. Routine screening for immunoglobulins during the infection-free period could result in the discovery of previously unrecognized immunoglobulin deficiencies in patients with a history of bacteremic pneumococcal infection.

Increasing resistance to penicillin in Streptococcus pneumoniae in southern Sweden

The susceptibility to penicillin of 6 prevalent pneumococcal types isolated from nasopharynx in 1992 was compared with that of corresponding types from 1980-82. The 6 types or groups, 6, 9, 14, 15, 19 and 23, constituted 78% of consecutive isolates. 19/204 isolates in 1992 were intermediately resistant (MIC 0.12-1.0 mg/l) in comparison with 1/194 from 1980-82 (p < 0.001). Resistant strains (MIC > or = 2 mg/l) were not found. Of group 15, no fewer than 10/31 isolates were intermediately resistant, which may support the clonal origin and spread of penicillin-resistant pneumococci. At least 5.0% of nasopharyngeal isolates are now intermediately resistant to penicillin. This figure is substantially higher than the 2% earlier reported in Sweden.

Bronchoscopic diagnosis of pulmonary infections in a heterogeneous, nonselected group of patients

Fiberoptic bronchoscopy with bronchoalveolar lavage and protected specimen brush technique has become an established method for etiologic diagnosis in severe forms of pulmonary infections during recent years. In this study, including 62 bronchoscopies in 53 patients, a standardized program, covering all important pulmonary pathogens, has been evaluated in a heterogeneous group of patients. Results providing therapeutic guidelines were obtained in 53 percent (16/30) of the immunocompromised patients (including 5 bronchoscopies on HIV-positive patients), but only 19 percent (6/32) of the immunocompetent patients (p < 0.001). We conclude that bronchoscopy is of great value for diagnosing pulmonary infections in immunocompromised patients. In immunocompetent patients, the diagnostic yield is lower and the indication for bronchoscopy must be established for each individual patient based on clinical importance, resources, and risk. When bronchoscopy is performed, we believe that a standardized program like ours reduces the risk of missing important pathogens.

Recurrent pneumonia: a review of 90 adult patients

Recurrent pneumonia is still an important problem. In this retrospective study we reviewed the records of 90 patients with a history of 3 or more episodes of acute pneumonia. The 90 patients accounted for altogether 347 episodes of acute pneumonia, treated at the Department of Infectious Diseases, Lund. 12 patients died while being treated for pneumonia at the department. Pneumonia alone caused the death in 7 of these 12 patients. In all, 51 of the patients died during the 11-year study period. Death certificates, stating the cause of death, were available in 38 cases, and pneumonia was the direct cause of death in 15 patients. Most of the infections were community-acquired, only 47 were nosocomial, 20/90 patients suffered from disorders associated with immune deficiency, and 70 patients had other predisposing illnesses. We found a larger number of underlying immunoglobulin deficiencies (11 patients of 38 investigated) than previously reported. Of 13 patients without other known, predisposing conditions, hypogammaglobulinemia was found in 3 patients. We suggest that patients with recurrent pneumonia should be thoroughly investigated, in order to find previously unrecognized immune deficiency.