Quantifications of dendrochronological information from contrasting microdensitometric measuring circumstances of experimental wood samples

We analyzed how the pretreatment method of Scots pine (Pinus sylvestris L.) wood specimens together with X-ray methodology applied for density analyses affect resulting tree-ring data and derived proxy-based climate information. We also evaluated whether these results from two contrasting laboratory circumstances could be homogenized by applying dendroclimatic statistical methods. For this study, we measured a pair of X-ray based microdensitometry datasets using double samples of subfossil and recent wood specimens. Dendrochronological information of earlywood and latewood series was examined to determine for alterations in the resulting data. We found that the level of overall density, its trend over cambial ages and the growth amplitude altered due to the sample pretreatment/density measuring exercise, which means that comparisons of heterogeneous datasets should be, in general, regarded cautiously. Dendrochronological standardization did, however, even out several potentially biasing influences from the differing overall densities and their trends. The two latewood (maximum) density chronologies yielded paleoclimatic reconstructions which both calibrated and verified satisfactorily with the instrumental warm-season (March-September) mean temperatures. The transfer functions were found to further equalize the differences between the two proxy records. We recommend (if no strictly homogenous data are available) reconciling similar data assemblages through transfer functions with multiple independent variables.

Management of a child with suspected acute septic arthritis

Acute septic arthritis of childhood is a potentially devastating disease that causes permanent disability and can result in death. Traditional treatment consists of a prolonged course of intravenous antibiotics combined with aggressive surgery. However, this approach is challenged by trials showing satisfactory outcomes with shorter treatment and less invasive surgery. Diagnostic arthrocentesis alone and an antibiotic for a fortnight, including initial intravenous administration for 2-4 days, suffice in most non-neonatal cases. A good penetrating agent, such as clindamycin or a first-generation cephalosporin, exceptionally high doses, and administration four times a day are probably key factors. If the symptoms and signs subside within a few days, and the serum C-reactive protein level drops below 20 mg/l, the antibiotic can usually be safely discontinued. Methicillin-resistant Staphylococcus aureus is a concern, but fortunately, most strains have retained susceptibility to clindamycin. The above guidance is not applicable to neonates and immunocompromised patients who may require a different approach.

Antibiotic treatment for acute haematogenous osteomyelitis of childhood: moving towards shorter courses and oral administration

Acute haematogenous osteomyelitis (AHOM) of childhood usually affects the long bones of the lower limbs. Although almost any agent may cause AHOM, Staphylococcus aureus is the most common bacterium, followed by Streptococcus pneumoniae and, in some countries, Salmonella spp. and Kingella kingae. Magnetic resonance imaging (MRI) has improved the diagnostic accuracy of traditional radiography and scintigraphy. Except for the pre-treatment diagnostic sample from bone before the institution of antibiotic therapy, no other surgery is usually required. Traditionally, non-neonatal AHOM has been treated with a 1-3-month course of antibiotics, including an intravenous (i.v.) phase for the first weeks, but recent prospective randomised studies challenge this approach. For most uncomplicated cases, a course of 20 days including an i.v. period of 2-4 days suffices, provided large enough doses of a well-absorbed agent (clindamycin or a first-generation cephalosporin, local resistance permitting) are used, administration is four times daily and most symptoms and signs subside within a few days. Serum C-reactive protein (CRP) is a good guide in monitoring the course of illness, and the antimicrobial can usually be discontinued if CRP has decreased to <20 mg/L. Newer and costly agents, such as linezolid, should be reserved for cases due to resistant S. aureus strains. AHOM in neonates and immunocompromised patients probably requires a different approach. Because sequelae may develop slowly, follow-up for at least 1 year post hospitalisation is recommended.

Vaccination greatly reduces disease, disability, death and inequity worldwide

In low-income countries, infectious diseases still account for a large proportion of deaths, highlighting health inequities largely caused by economic differences. Vaccination can cut health-care costs and reduce these inequities. Disease control, elimination or eradication can save billions of US dollars for communities and countries. Vaccines have lowered the incidence of hepatocellular carcinoma and will control cervical cancer. Travellers can be protected against "exotic" diseases by appropriate vaccination. Vaccines are considered indispensable against bioterrorism. They can combat resistance to antibiotics in some pathogens. Noncommunicable diseases, such as ischaemic heart disease, could also be reduced by influenza vaccination. Immunization programmes have improved the primary care infrastructure in developing countries, lowered mortality in childhood and empowered women to better plan their families, with consequent health, social and economic benefits. Vaccination helps economic growth everywhere, because of lower morbidity and mortality. The annual return on investment in vaccination has been calculated to be between 12% and 18%. Vaccination leads to increased life expectancy. Long healthy lives are now recognized as a prerequisite for wealth, and wealth promotes health. Vaccines are thus efficient tools to reduce disparities in wealth and inequities in health.

Vaccination greatly reduces disease, disability, death and inequity worldwide

In low-income countries, infectious diseases still account for a large proportion of deaths, highlighting health inequities largely caused by economic differences. Vaccination can cut health-care costs and reduce these inequities. Disease control, elimination or eradication can save billions of US dollars for communities and countries. Vaccines have lowered the incidence of hepatocellular carcinoma and will control cervical cancer. Travellers can be protected against "exotic" diseases by appropriate vaccination. Vaccines are considered indispensable against bioterrorism. They can combat resistance to antibiotics in some pathogens. Noncommunicable diseases, such as ischaemic heart disease, could also be reduced by influenza vaccination. Immunization programmes have improved the primary care infrastructure in developing countries, lowered mortality in childhood and empowered women to better plan their families, with consequent health, social and economic benefits. Vaccination helps economic growth everywhere, because of lower morbidity and mortality. The annual return on investment in vaccination has been calculated to be between 12% and 18%. Vaccination leads to increased life expectancy. Long healthy lives are now recognized as a prerequisite for wealth, and wealth promotes health. Vaccines are thus efficient tools to reduce disparities in wealth and inequities in health.

Acute infections, infection pressure, and atopy

BACKGROUND

During the recent years, a new theory postulating that lack of early childhood infections would increase the prevalence rate of allergies has rapidly gained momentum. This hygiene hypothesis has been widely disseminated to the general public and it has been suggested that vaccinations would accordingly indirectly increase rates of atopy. We thus investigated associations between acute infections, infection pressure (i.e. number of daily child contacts) and atopy in one of the largest population-based medical surveys ever published in the medical literature.

METHODS

Almost all Finns born between 1976 and 1984 and a sample of older teenagers aged up to 19 years (n=5 47 190) were vaccinated and questioned to establish clinical history of mumps and rubella and manifestations of atopy (rhinoconjunctivitis, eczema, and asthma) in 1982-1986. A subsample (n=37 733) including all those subjects who were vaccinated during the first 2 months of the measles, mumps, and rubella (MMR) programme were also queried information about upper respiratory infections (URIs) and infection pressure. Crude and adjusted prevalence ratios of atopy among those with infectious disease history compared with those without it were calculated.

RESULTS

The risk of URI and a history of mumps and rubella increased with the number of daily contacts. This association was apparent especially among the youngest subjects with regard to URIs whereas the proportion with histories of mumps and rubella increased with increasing infection pressure more clearly among the 6-year-olds. Atopy was not associated with daily child contacts among pre-schoolers. Children with histories of repeated URIs and MMR diseases had substantially more atopy than those with lower URI or MMR disease rates.

CONCLUSIONS

Atopic subjects seem to be especially prone to clinically apparent acute respiratory tract infections, and might be in particular need of protection by immunizations. This study does not support the idea that the prevalence of atopy in affluent countries would be affected from disappearing respiratory tract infections.

Epidemiology of rubella in Finland

Before rubella vaccination programmes began, rubella infection was prevalent in Finnish children. The disease occurred as epidemics at intervals of a few years. Rubella infection was most often contracted between the ages of 2 and 12 years. Vaccinations specifically aimed at eradicating rubella were begun with monocomponent vaccine in the mid-1970s, and the measles, mumps and rubella (MMR) vaccination programme with two injections got underway in 1982. A clear reduction in rubella cases was evident a few years after the launch of the MMR programme. Owing to a sufficiently high vaccination coverage (>95% since 1987), circulation of the indigenous rubella virus in the Finnish population ceased in the late 1990s. Some rubella cases have been imported to Finland since elimination, but they have not caused any secondary cases. This shows unambiguously that protection against rubella continues to be effective, although our cohort studies imply that the vaccine induced antibody levels do decrease with time. The MMR programme has also eliminated congenital rubella syndrome (CRS) from the country. The last CRS case was recorded in 1986. As a result of the high coverage two dose MMR vaccination programme, rubella was successfully eliminated from Finland. How long the acquired protection will last remains to be seen.

Epidemiology of rubella in Finland

Before rubella vaccination programmes began, rubella infection was prevalent in Finnish children. The disease occurred as epidemics at intervals of a few years. Rubella infection was most often contracted between the ages of 2 and 12 years. Vaccinations specifically aimed at eradicating rubella were begun with monocomponent vaccine in the mid-1970s, and the measles, mumps and rubella (MMR) vaccination programme with two injections got underway in 1982. A clear reduction in rubella cases was evident a few years after the launch of the MMR programme. Owing to a sufficiently high vaccination coverage (&gt;95% since 1987), circulation of the indigenous rubella virus in the Finnish population ceased in the late 1990s. Some rubella cases have been imported to Finland since elimination, but they have not caused any secondary cases. This shows unambiguously that protection against rubella continues to be effective, although our cohort studies imply that the vaccine induced antibody levels do decrease with time. The MMR programme has also eliminated congenital rubella syndrome (CRS) from the country. The last CRS case was recorded in 1986. As a result of the high coverage two dose MMR vaccination programme, rubella was successfully eliminated from Finland. How long the acquired protection will last remains to be seen.

Component carbon fluxes and their contribution to ecosystem carbon exchange in a pine forest: an assessment based on eddy covariance measurements and an integrated model

We used a combination of eddy flux, canopy, soil and environmental measurements with an integrated biophysical model to analyze the seasonality of component carbon (C) fluxes and their contribution to ecosystem C exchange in a 50-year-old Scots pine forest (Pinus sylvestris L.) in eastern Finland (62 degrees 47' N, 30 degrees 58' E) over three climatically contrasting years (2000-2002). Eddy flux measurements showed that the growing Scots pine forest was a sink for CO2, with annual net C uptakes of 131, 210 and 258 g C m-2> year-1 in 2000, 2001 and 2002, respectively. The integrated process model reproduced the annual course of daily C flux above the forest canopy as measured by the eddy covariance method once the site-specific component parameters were estimated. The model explained 72, 66 and 68% of the variation in daily net C flux in 2000, 2001 and 2002, respectively. Modeled annual C loss by respiration was 565, 629 and 640 g C m-2 year-1, accounting for 77, 77 and 65% of annual gross C uptake, respectively. Carbon fluxes from the forest floor were the dominant contributors to forest ecosystem respiration, with the fractions of annual respiration from the forest floor, foliage and wood being 46-62, 27-44 and 9-10%, respectively. The wide range in daily net C uptake during the growing season was largely attributable to day-to-day fluctuations in incident quantum irradiance. During just a few days in early spring and late autumn, ecosystem net C exchange varied between source and sink as a result of large daily changes in temperature. The forest showed a greater reduction in gross C uptake by photosynthesis than in C loss by respiration during the dry summer of 2000, indicating that interannual variability in ecosystem net C uptake at this site was modified mostly by summer rainfall and vapor pressure deficit.

Clinical "pneumococcal pneumonia" due to Moraxella osloensis: case report and a review

A previously healthy 6-y-old girl presented with a disease very similar to pneumococcal pneumonia. However, Moraxella osloensis was isolated by lung tap. The patient responded well to a course of parenteral penicillin. This is probably the first documented case of community-acquired pneumonia associated with this agent. Clinical isolates of M. osloensis are rare and its pathogenesis has not been delineated; however, a literature review suggests that the organism is more common than is generally recognized.

Successful shortening from seven to four days of parenteral beta-lactam treatment for common childhood infections: a prospective and randomized study

OBJECTIVES

To explore whether 4-day parenteral beta-lactam therapy is as effective as 7-day therapy for children hospitalized for parenteral antimicrobials.

METHODS

A series of patients aged 3 months to 15 years who fulfilled strict criteria for bacterial pneumonia, other respiratory infections, sepsis-like infections, and other acute infections were prospectively randomized to receive parenteral penicillin or cefuroxime randomly for 4 or 7 days. Besides blood and throat cultures, the etiology was searched by serology for 23 different agents.

RESULTS

Of 154 children analyzed, a probable etiology was established in 96. Of those, a bacterial infection, with or without concomitant viral infection, was disclosed in 80% and 94% in the 4-day and 7-day treatment groups, respectively; pneumococcus being the commonest agent. There was one possible treatment failure in the 4-day group, but with a questionable relation to the short course. Three patients in the 4-day and two in the 7-day group underwent treatment changes, or were rehospitalized within 30 days. All children recovered entirely.

CONCLUSIONS

Shortening parenteral beta-lactam treatment to 4 days in infections for which most parenteral antimicrobials are instituted, is not only safe, but reduces costs, is ecologically sound, and minimizes the risks of nosocomial infections and other adverse effects of treatment.

Reappraisal of lung tap: review of an old method for better etiologic diagnosis of childhood pneumonia

Identification of the etiology of childhood pneumonia is difficult, even in the cases that most likely have bacterial origins. A positive blood culture result is diagnostic but rare (< 10% of cases), and other noninvasive microbiological methods are nonspecific or are at least shadowed by interpretation problems. However, lung tap (or aspiration), a method developed a century ago, warrants reappraisal, especially since the prevalence of pneumococcal resistance to penicillin is increasing. An analysis of 59 studies that were published in 6 languages led us to conclude that (1) bacterial etiology is disclosed in approximately 50% of cases (virological tests were rarely done); (2) lung tap is safer than is generally considered; (3) potential pneumothorax is mostly symptomless and resolves spontaneously without impairing recovery; and (4) in comparison with routine diagnostic tools, lung tap offers so many advantages that it warrants reconsideration at centers where personnel have experience in handling potential pneumothorax.

Allergic reactions to measles-mumps-rubella vaccination

OBJECTIVE

Immunization of egg-allergic children against measles, mumps, and rubella (MMR) is often deferred or even denied, although the safety of this vaccination has been clearly shown. Moreover, the majority of severe allergic reactions have occurred in egg-tolerant vaccinees. Other allergenic vaccine components have been sought, and gelatin has been suggested as one cause of allergic adverse events. The aim of this study was to further characterize the actual allergenic vaccine components.

METHODS

Serum samples from 36 recipients of MMR vaccine with anaphylaxis, urticaria with or without angioedema, asthmatic symptoms, or Henoch-Schönlein purpura were analyzed by CAP System radioallergosorbent test (RAST) and immunospot methods to detect the allergenic vaccine component. To evaluate the correspondence between the findings in the CAP System RAST or the immunospot and clinical symptoms, histories of allergies and present hypersensitivity symptoms were assessed.

RESULTS

Of the 36 participants, 10 were demonstrated to be allergic to gelatin. Seven of them had persistent allergic symptoms, possibly attributable to foods containing gelatin or cross-reactive allergens. The results of the immunospot suggested concomitant allergy to gelatin and egg, chicken, and feathers, as well as cow's milk, or they reflected allergen cross-reactivity.

CONCLUSIONS

Although severe allergic adverse events attributable to MMR vaccination are extremely rare, all serious allergic reactions should be further assessed to detect the likely causative vaccine component, including gelatin. The current recommendation for immunization of egg-allergic persons according to standard MMR vaccination schedules is reinforced. measles, mumps, and rubella vaccine, immunization, adverse effects, allergic reactions, gelatin allergy, CAP System, radioallergosorbent test, immunospot, immunoglobulin E.

Risk of Guillain-Barré syndrome after measles-mumps-rubella vaccination

OBJECTIVE

To assess the postulated causal association between measles-mumps-rubella (MMR) vaccination and Guillain-Barré syndrome (GBS).

STUDY DESIGN

Active retrospective study based on linkage of the nationwide hospital discharge register with individual vaccination records. All patients hospitalized for treatment of GBS in Finland between November 1982 and December 1986 were included in the study.

RESULTS

During the study period, 189 patients were hospitalized for treatment of GBS, and approximately 630,000 vaccine recipients received 900,000 doses of MMR vaccine; 24 of the 189 patients represented the prevailing target population for MMR vaccination, of whom 20 were vaccinated. MMR vaccination did not cause any increase over the background incidence of GBS, and no clustering of cases of GBS occurred at any time point after administration of MMR vaccine. The interval between vaccination and onset of symptoms of GBS exceeded the designated risk period of 6 weeks in all cases, varying from 80 days to years. MMR vaccination after recovery from GBS did not cause relapses of the illness. Respiratory or gastrointestinal tract infection predated the onset of GBS by 3 to 30 days in 20 (83%) of the 24 patients.

CONCLUSIONS

No causal association seems to prevail between MMR vaccination and GBS.

Seroetiology of acute lower respiratory infections among hospitalized children in Beijing

BACKGROUND

Little is known of the etiology of childhood acute lower respiratory infections in China, where the use of antimicrobials is indiscriminate. Trials to change such a policy require etiologic data, especially on the bacteria most relevant to these common diseases.

METHODS

One hundred consecutive infants and children from 3 months to 14 years of age with symptoms and signs compatible with acute lower respiratory infections were studied prospectively in the largest pediatric hospital in Beijing from February to May, 1997. Blood culture, thorax radiography and paired sera for 20 microbiologic assays were taken, and the course of illness was monitored uniformly. Disease severity was graded.

RESULTS

In 24 cases there was evidence only of bacterial etiology, and in 5 solely viral agents were found; 3 children probably had a mixed bacterial-viral infection. Surprisingly no pneumococcal infection was detected, Mycoplasma pneumoniae (n = 21), Haemophilus influenzae type b (n = 8) and Chlamydia pneumoniae (n = 7) being the dominant bacteria. All children recovered.

CONCLUSIONS

Routine use of antimicrobials for these patients seems unjustified. Serologic evidence for the H. influenzae type b etiology is encouraging in terms of vaccination, but confirmatory studies are needed.

Burden of meningitis and other severe bacterial infections of children in africa: implications for prevention

Apart from meningococcal disease in the sub-Saharan meningitis belt, the incidence and impact of life-threatening bacterial diseases in children across Africa have not been quantified. The clinical and epidemiological data on pneumococcal, Haemophilus influenzae type b (Hib), and other forms of bacterial meningitis, as well as data on other severe bacterial infections throughout the continent were scrutinized. Pneumococci were the leading causative agents of nonepidemic meningitis and other bacteremic diseases, followed by Hib. Meningococcal diseases were less common. Mortality rates associated with pneumococcal, Hib, and meningococcal meningitis were 549 (45%) of 1211 patients, 389 (29%) of 1352 patients, and 104 (8%) of 1236 patients, respectively; sequelae occurred in 50%, 40%, and 10% of cases. At 0-4 years of age, the estimated incidences of Hib meningitis and all classic Hib diseases were 70 and 100 cases per 100,000 population per year, accounting for approximately 90,000 and 120,000 cases per year, respectively. Including older age groups and, especially, nonbacteremic Hib pneumonia in the estimates of Hib disease in Africa increased the overall numbers manifold; the numbers of pneumococcal infections were even greater. The only realistic way to combat these severe infections efficaciously would be through widespread vaccination, starting with Hib conjugates.

Serious adverse events after measles-mumps-rubella vaccination during a fourteen-year prospective follow-up

BACKGROUND

Several disorders have been attributed to measles-mumps-rubella (MMR) vaccination during the past decade. The aim of this prospective follow-up study was to identify serious adverse events causally related to MMR vaccination.

METHODS

When the MMR vaccination program was launched in Finland in 1982, a countrywide surveillance system was set up to detect serious adverse events associated with MMR. To obtain detailed case histories vaccinees' clinical charts were reviewed. Serum samples were analyzed to trace concurrent infections.

SETTING

All hospitals and health centers in Finland from 1982 through 1996.

RESULTS

Immunization of 1.8 million individuals and consumption of almost 3 million vaccine doses by the end of 1996 gave rise to 173 potentially serious reactions claimed to have been caused by MMR vaccination. In all, 77 neurologic, 73 allergic and 22 miscellaneous reactions and 1 death were reported, febrile seizure being the most common event. However, 45% of these events proved to be probably caused or contributed by some other factor, giving an incidence of serious adverse events with possible or indeterminate causal relation with MMR vaccination of 5.3 per 100,000 vaccinees or 3.2 per 100,000 vaccine doses.

CONCLUSIONS

Causality between immunization and a subsequent untoward event cannot be estimated solely on the basis of a temporal relation. Comprehensive analysis of the reported adverse reactions established that serious events causally related to MMR vaccine are rare and greatly outweighed by the risks of natural MMR diseases.

Prevalence of diarrheagenic Escherichia coli in finns with or without diarrhea during a round-the-world trip

The incidence of diarrhea and the prevalence of bacterial enteropathogens, viruses, and parasites in feces of subjects with and without diarrhea were evaluated in 204 Finns traveling round the world (from Finland to China, Malaysia, Australia, Fiji, Chile, and Brazil and back to Finland). Special emphasis was placed on the finding of diarrheagenic Escherichia coli (enterotoxigenic, enteropathogenic, Shiga toxin-producing, and enteroaggregative strains) by PCR from growth on primary culture plates. From the PCR-positive samples, corresponding strains were isolated, confirmed as E. coli, and O serotyped. Of all the subjects, 37% experienced a total of 90 episodes of diarrhea. No adenoviruses or rotaviruses were detected, and findings of parasites were insignificant. In contrast, enteropathogenic bacteria were present in 62% of the 65 diarrheal and in 33% of the 127 nondiarrheal samples (P < 0.001); diarrheagenic E. coli strains were found in 35 and 26% of these, respectively (not statistically significant). As a single pathogen, E. coli was found in 20 and 24% of samples (not significant). Of all diarrheagenic E. coli strains, enteropathogenic strains were the most commonly found independently of the clinical picture of the subjects, whereas Salmonella enterica as a single pathogen was the most common non-E. coli organism found in diarrheal samples. Multiple bacterial pathogens were found 10 times more commonly in diarrheal than in nondiarrheal samples (20 versus 2%; P < 0.001).

Narrow- versus broad-spectrum parenteral anatimicrobials against common infections of childhood: a prospective and randomised comparison between penicillin and cefuroxime

Overuse of broad-spectrum antimicrobials has resulted in increasing bacterial resistance in many countries. We hypothesised that common childhood infections requiring parenteral medication are still curable with narrow-spectrum and inexpensive penicillin. A prospective and randomised study was performed in two referral hospitals in Helsinki. A total of 154 children aged 3 months to 15 years with pneumonia or other lower respiratory infections, sepsis-like infections, or other common acute infections warranting hospitalisation and parenteral antimicrobials were included. At random, 50% of children received procaine penicillin intramuscularly, the other 50% cefuroxime intravenously for 4-7 days. The course of illness was monitored with predetermined laboratory and radiological indices, by filling in a special form daily and a follow-up for 30 days after discharge. The infectious agent was searched for with a large laboratory set-up covering 23 bacterial, viral or protozoan species. The two groups were very similar at presentation. Probable aetiology was disclosed in 56% of the penicillin and in 68% of the cefuroxime recipients, the leading agent in both groups being Pneumococcus. In 8% only a viral aetiology was found. The children recovered with the same speed, regardless of which antimicrobial used, there being one possible failure in each group but no difference in the frequency of needing a physician again within 1 month of discharge. No adverse event was attributable to either drug.

CONCLUSION

Procaine penicillin is as effective and safe as cefuroxime for common community-acquired infections in immunocompetent children.

Mumps and rubella eliminated from Finland

Many countries use trivalent measles-mumps-rubella (MMR) vaccine for their mumps and rubella immunization programs. In Finland, a national 2-dose MMR vaccination program for children, free of charge and on a voluntary basis, was launched in 1982. Serological confirmation of all suspected cases of mumps and rubella has been required since 1987. Despite intensive surveillance, no persistent sequelae or deaths attributable to vaccination have been detected. Indigenous mumps and rubella were eliminated in 1996, but 4 imported cases of mumps and 2 of rubella occurred from 1997 to 1999. Lack of secondary cases indicates sufficient immunity in the community. Compared with an epidemic year, up to thousands of cases of mumps meningoencephalitis and orchitis and around 50 cases of congenital rubella syndrome are now avoided annually. A 2-dose vaccine regimen in children during the last 17 years (1983-1999) has interrupted circulation of the target viruses entirely. Finland is the first country documented to be free of indigenous mumps and rubella (measles was eliminated in 1996). Despite the ongoing possibility of imported disease, major outbreaks probably can be avoided by maintaining high vaccination coverage and the 2-dose policy. JAMA. 2000;284:2643-2647.

Day-to-day reactogenicity and the healthy vaccinee effect of measles-mumps-rubella vaccination

OBJECTIVE

Revaccination policies adopted in many countries to control measles have raised various safety issues including those concerning the second vaccine dose. We performed a prospective, double-blind, crossover trial among twins receiving a measles-mumps-rubella (MMR) vaccine.

STUDY DESIGN

The study comprised 1162 monozygous and heterozygous twins, each of whom randomly received placebo and then vaccine, or vice versa, 3 weeks apart, at 14 to 83 months of age. Most of the oldest children had previously been vaccinated against measles, and one half of the remainder of children had had the disease. Symptoms and signs were recorded daily on structured forms. Statistical methods included a complex analysis of the vaccine attributability of the symptoms and conditional logistic regression.

RESULTS

Vaccination-attributable events occurred in 6% overall. At 14 to 18 months of age, reactions developed between days 6 and 14, peaking at day 10. The clearest vaccine-attributable effect was fever exceeding 101.3 degrees F (38. 5 degrees C; odds ratio: 3.28; 95% confidence interval: 2.23-4.82; P <.001), but the same trend was found for rash, arthralgia, conjunctivitis, staying in bed, drowsiness, and irritability. At 6 years of age, systemic reactions occurred 5 to 15 times less frequently, only arthralgia being associated with vaccination. Zygocity, gender, history of allergy, or infections did not modify reactions. Instead, respiratory symptoms developed within days postinjection to a level of 15% to 20% without subsequent decline and with no difference between vaccinees and placebo recipients.

CONCLUSION

Vaccination was avoided during infections, but many small children became mildly ill within a week or so with no relation to vaccination (the healthy vaccinee effect). MMR vaccine was virtually nonreactogenic when given at 6 years of age. vaccine, measles, mumps, rubella, reactogenicity, adverse events, zygocity, healthy vaccinee effect.

Duration of rubella immunity induced by two-dose measles, mumps and rubella (MMR) vaccination. A 15-year follow-up in Finland

A national two-dose vaccination program with a combined measles, mumps and rubella (MMR-II) vaccine was introduced in Finland, in 1982, immunizing children at the ages of 14-18 months and 6 years. Antibody levels were determined from serial samples from a group of originally 350 children during 15 years. The latest samples were taken 15.5 years after the first vaccination and 70% of the children could still be reached. The aim of this study was to determine the kinetics of rubella antibodies induced by the MMR-II vaccine in these individuals. Rubella antibodies were analyzed from three different cohorts: Group I seronegative children (n=166) vaccinated at 14-18 months and 6 years, Group II seronegative children (n=139) and Group III seropositive children (n=16) vaccinated at 6 and 11-13 years. Samples collected 0-9 years after vaccination were analyzed by hemolysis-in-gel (HIG) and later samples by enzyme immunoassay (EIA) techniques. The primary vaccination induced 100% seropositivity in vaccinees with a mean zone diameter of 10 (+/-1.3), 10.2 (+/-1.1) and 11.5 (+/-0.9) mm, in Groups I, II and III, respectively. The seropositivity rate was still high at 15 years, 99%, 100% and 100% with the geometric mean titer 23, 46 and 105 IU/ml, respectively. At 15 years, antibody levels <15 IU/ml which is the suggested protective level, were found in 31, 9 and 0% of children in Groups I, II and III, respectively. Because almost a third of the individuals in Group I now, at the age of 17 years, had low levels of rubella antibodies, it is possible that rubella infections may re-emerge during pregnancy. A careful surveillance including serological follow-up is therefore very important.

Secondary measles vaccine failures identified by measurement of IgG avidity: high occurrence among teenagers vaccinated at a young age

Failure to seroconvert (primary vaccine failure) is believed to be the principal reason (approx. > 95%) why some vaccinees remain susceptible to measles and is often attributed to the persistence of maternal antibodies in children vaccinated at a young age. Avidity testing is able to separate primary from secondary vaccine failures (waning and/or incomplete immunity), but has not been utilized in measles epidemiology. Low-avidity (LA) and high-avidity (HA) virus-specific IgG antibodies indicate primary and secondary failure, respectively. Measles vaccine failures (n = 142; mean age 10.1 years, range 2-22 years) from an outbreak in 1988-9 in Finland were tested for measles-virus IgG avidity using a protein denaturating EIA. Severity of measles was recorded in 89 failures and 169 non-vaccinees (mean age 16.2 years, range 2-22 years). The patients with HA antibodies (n = 28) tended to have clinically mild measles and rapid IgG response. Among failures vaccinated at < 12, 12-15 and > 15 months of age with single doses of Schwarz-strain vaccine in the 1970s, 50 (95% CI 1-99), 36 (CI 16-56) and 25% (CI 8-42) had HA antibodies, respectively. When a single measles, mumps and rubella (MMR) vaccine had been given after 1982 at 15 months of age, only 7% (CI 0-14) showed HA antibodies. Omitting re-vaccinees and those vaccinated at < 15 months, Schwarz-strain recipients had 3.6 (CI 1.1-11.5) higher occurrence of HA responses compared to MMR recipients. Apart from one municipality, where even re-vaccinees had high risk of primary infection, 89% (CI 69 to approximately 100) of the infected re-vaccinees had an HA response. Secondary measles-vaccine failures are more common than was more previously thought, particularly among individuals vaccinated in early life, long ago, and among re-vaccinees. Waning immunity even among individuals vaccinated after 15 months of age, without the boosting effect of natural infections should be considered a relevant possibility in future planning of vaccination against measles.

Worldwide Haemophilus influenzae type b disease at the beginning of the 21st century: global analysis of the disease burden 25 years after the use of the polysaccharide vaccine and a decade after the advent of conjugates

Vaccination against Haemophilus influenzae type b (Hib) diseases began a quarter of a century ago with a polysaccharide vaccine; this vaccine was followed by four different conjugates 10 years later. In this review, the burden of global Hib disease is quantified following this 25-year period of vaccine availability to determine the potential impact of conjugate vaccines. This task was accomplished by analysis of data available in 10 languages in 75 geographical regions of over 50 countries. All severe Hib diseases, not only meningitis, were characterized, and special attention was paid to the most vulnerable age group, i.e., children aged 0 to 4 years. Prior to vaccination, the weighted worldwide incidence of meningitis in patients younger than 5 years was 57/100,000, and for all Hib diseases except nonbacteremic pneumonia, it was 71/100,000, indicating 357,000 and 445,000 cases per year, respectively. At least 108,500 of these children died. For all age groups combined, there were 486,000 cases of Hib disease, excluding pneumonia, with 114,200 deaths and probably an equal number of sequelae per annum. If the figures for nonbacteremic pneumonia are included, a conservative estimate is that over 2.2 million cases of infection and 520,000 deaths from Hib disease occurred worldwide, but the true numbers might have been greater. Despite these large numbers and availability of safe and efficacious vaccines, only 38,000 cases annually are prevented-a meager 8% or less than a 2% reduction in cases, depending on whether nonbacteremic pneumonia is included in the calculations. Although vaccination has had great success in some affluent countries, the current level of activity has had a very small impact globally. The use of conjugates, preferably with a reduced number of doses and in combination with other vaccines or perhaps in fractional doses, should be extended to less privileged countries, where most Hib disease occurs.

Randomized trial of four vs. seven days of ceftriaxone treatment for bacterial meningitis in children with rapid initial recovery

BACKGROUND

Seven days or more of antimicrobial treatment is the standard for bacterial meningitis, although third generation cephalosporins are usually able to sterilize cerebrospinal fluid within 24 h. The limited experience from shorter regimens in children is encouraging, and we hypothesized that in rapidly recovering patients older than 3 months of age it would pose no risk for adverse outcome.

METHODS

Strict clinical and laboratory criteria were used to define rapid initial recovery, in which case ceftriaxone therapy was either stopped after 4 days (4 injections) in children born on even dates (N = 53) or continued for 7 days in patients born on odd dates (N = 47). Outcomes were compared on Day 7 of hospitalization and at 1 to 3 months after discharge.

RESULTS

On Day 7 no differences (P > 0.05 for each criteria) were observed between the 4-day and the 7-day groups regarding fever, clinical signs or serum C-reactive protein concentration. At the follow-up visit 1 to 3 months after discharge the 4-day group had fewer sequelae than the 7-day group (0% vs. 5% neurologic sequelae, P = 0.39 and 3% vs. 9% hearing loss, P = 0.49, respectively). One child in the 4-day group who had fully recovered was subsequently readmitted 53 days after the first hospitalization with recurrent Haemophilus influenzae meningitis.

CONCLUSIONS

Four days of ceftriaxone therapy proved to be a safe alternative in patients with rapid initial recovery from bacterial meningitis. A 4-day course of treatment is particularly beneficial for countries with limited resources.

Measles history and atopic diseases: a population-based cross-sectional study

CONTEXT

Many recent cross-sectional studies have suggested that lack of early exposure to communicable diseases, including measles, in affluent countries may have increased rates of atopic disease.

OBJECTIVE

To study the association between natural measles infection and atopy.

DESIGN AND SETTING

Cross-sectional nationwide study in Finland using data gathered between November 1, 1982, and June 30, 1986.

SUBJECTS

A total of 547910 individuals aged 14 months to 19 years who at the time of measles-mumps-rubella (MMR) vaccination had relevant information collected on the occurrence of measles and allergic rhinitis, eczema, and asthma.

MAIN OUTCOME MEASURES

Lifetime occurrence of atopic manifestations in subjects who had had measles compared with those who had not, expressed as age-specific and age-adjusted prevalence ratios.

RESULTS

The age-adjusted prevalence ratio of atopic manifestations among those who had had measles (n = 20 690) compared with those who had not (n = 527 220) was 1.32 (95% confidence interval [CI], 1.27-1.36) for eczema, 1.41 (95% CI, 1.33-1.49) for rhinitis, and 1.67 (95% CI, 1.54-1.79) for asthma. The positive association between measles and atopy was evident at all ages, in both urban and rural dwellers, and among subjects with many or few contacts at home or in day care.

CONCLUSIONS

Based on our data, measles and atopy occur more frequently together than expected, which does not support the hypothesis that experiencing natural measles infection offers protection against atopic disease.

Prophylaxis of bacterial meningitis

A comprehensive review of all major agents causing bacterial meningitis--meningococcus of the groups A, B, C, W135, and Y, pneumococcus, and Haemophilus influenzae type B (Hib)--is done in terms of preventing them by chemoprophylaxis or vaccination. Some evidence suggests that the group B meningococcal disease may also be very likely preventable by a vaccine that is already available. Excellent Hib conjugates use a technique that is expected to revolutionize immunoprophylaxis against most meningococcal and pneumococcal diseases in the near future. Unfortunately, the high cost of conjugate vaccines restricts their use in many poor countries.

C-reactive protein is useful in distinguishing Gram stain-negative bacterial meningitis from viral meningitis in children

OBJECTIVE

To clarify to what extent Gram stain-negative bacterial meningitis can be distinguished from viral meningitis by assessment of cerebrospinal fluid (CSF) and blood indices and serum C-reactive protein (CRP) in children over 3 months of age.

DESIGN

Common CSF indices, blood leukocyte counts, and serum CRP values were compared between patients with bacterial meningitis who had a positive CSF bacterial culture but a negative Gram stain and patients with viral meningitis.

POPULATION

Three hundred twenty-five consecutive patients with CSF culture-proven bacterial meningitis, for whom Gram stain was negative in 55 cases, and 182 children with proven or presumed viral meningitis.

RESULTS

Significant differences between patients with bacterial and viral meningitis were found in all indices with large overlap in all except serum CRP. In patients with bacterial meningitis, the mean CSF glucose concentration, protein concentration, leukocyte count, blood leukocyte count, and serum CRP were 2.9 mmol/L (52 mg/dL), 1.88 g/L, 4540 x 10(6)/L, 18.0 x 10(9)/L, and 115 mg/L; and in those with viral meningitis, mean values were 3.3 mmol/L (59 mg/dL), 0.52 g/L, 240 x 10(6)/L, 10.6 x 10(9)/L, and <20 mg/L, respectively. Of the tests investigated in this study, only serum CRP was capable of distinguishing Gram stain-negative bacterial meningitis from viral meningitis on admission with high sensitivity (96%), high specificity (93%), and high negative predictive value (99%).

CONCLUSION

Exclusion of bacterial meningitis with only the conventional tests is difficult. Combined with careful physical examination and CSF analyses, serum CRP measurement affords substantial aid.

Twice vaccinated recipients are better protected against epidemic measles than are single dose recipients of measles containing vaccine

OBJECTIVE

To study measles risk after revaccination.

DESIGN

A population-based case-control study during an epidemic season.

MAIN OUTCOME MEASURE

Relative serologically confirmed measles risk.

PARTICIPANTS AND METHODS

153 vaccinated cases, mostly from rural areas, were serologically confirmed as measles at the central laboratory in 1988-89. A randomly selected group of 453 controls from either municipalities of vaccinated cases or from areas where measles attack rate was > 600/10(5), was identified via the population registry. Vaccination and measles histories of cases and controls were determined from official vaccination cards.

RESULTS

Once and twice vaccinated had crude relative risk 15.6 and 2.3 compared with thrice vaccinated. When cases who had received their first vaccination at less than 14 months of age were omitted from analysis, once vaccinated had 4.0 (95% CI 1.2, 16.6) times higher age adjusted measles risk compared with twice vaccinated. When, omission was extended to cases from one particular municipality where even revaccinees had high measles risk during an explosive outbreak the corresponding risk ratio was 17.8 (2.8, 67.8).

CONCLUSIONS

Twice vaccinated have better protection against epidemic measles compared with single dose recipients.

Spectrum and burden of severe Haemophilus influenzae type b diseases in Asia

The validity of the commonly held view that Haemophilus influenzae type b (Hib) diseases are rare in Asia is challenged in this article by a thorough analysis of the data available, often in languages other than English. The entire spectrum of Hib disease, not only meningitis, was taken into account, and over 100 reports from 25 countries were explored. Hib was the leading agent among nontuberculous childhood meningitis cases in two-thirds of 48 studies from 22 countries. Data from six countries showed that all the classical manifestations of invasive Hib diseases are also found in Asia, except epiglottitis, which was nearly absent. In Hong Kong Special Administrative Region of China Hib disease is rare, but otherwise the incidences seemed not to deviate much from those in Europe until recently, around 25 per 100,000 for meningitis and at least 40 per 100,000 per year for the classical Hib manifestations combined at age 0-4 years. In total, more than 200,000 cases of Hib disease are estimated to occur annually in Asia. Because nonbacteraemic Hib pneumonia remains mostly undetected, the total burden is probably significantly greater. The issue will be fully elucidated only by prospective epidemiological and clinical studies, but awaiting them should not delay large-scale vaccinations against Hib throughout Asia.

Perspective: a five-country analysis of the impact of four different Haemophilus influenzae type b conjugates and vaccination strategies in Scandinavia

Prior to vaccinations against invasive Haemophilus influenzae type b (Hib) diseases in Scandinavia, first initiated in Finland in 1986, the incidence of cases in those five countries was 49/100,000/year in 0- to 4-year-olds and 3.5/100,000 overall. During the following decade, Hib conjugates administered to young children had approximately 95% effectiveness, regardless of which conjugate was used, whether two or three primary doses were administered, and at what age in early infancy the first vaccination was given. The herd immunity effect has extended protection to older age groups. A similar effectiveness of different conjugates in five countries despite considerable diversity in approach suggests that the same impact would occur in other regions with comparable epidemiology. The Scandinavian experience supports the view that three primary vaccine doses are not imperative, thus suggesting that reducing doses of costly Hib vaccines would be one way to facilitate their usage in regions with limited resources.

Immunoreactivation of Epstein-Barr virus due to cytomegalovirus primary infection

Serological diagnosis of herpes virus infections is hampered by concurrent expression of IgM for heterologous members of this virus family. To assess the frequency of such multiple diagnostic findings and to understand their etiology, we sought by using IgG, IgM, and IgG avidity test serodiagnoses for Epstein-Barr virus (EBV) among immunocompetent or immune-suppressed patients with well-documented cytomegalovirus (CMV) primary infection. Controls had primary infection by EBV or had acute septic or severe respiratory infection. Among EBV-seropositive patients with CMV primary infection, a large proportion (13/56, 23%) showed antibody profiles of EBV reactivation: seroconversion of VCA IgM and/or > or = fourfold rise of VCA IgG, together with high or intermediate avidity of VCA IgG. Most of the CMV patients with EBV serodiagnosis showed also diagnostic HHV-6 antibody rises. In contrast to the frequently occurring CMV-induced EBV immunoreactivation, EBV primary infections did not appear to induce immunoreactivations of CMV (0/22). Only one (2%) CMV patient had a significant varicella zoster virus (VZV) antibody rise. The studies show that CMV is a particularly active inducer of some, but not all, members of the herpes virus family and suggest that the in vivo interplay between CMV and EBV occurs unidirectionally. The high frequency of heterologous herpes virus immunoreactivations poses demands on laboratory diagnosis.