Prevalence and clinical significance of chondromalacia isolated to the anterior margin of the lateral femoral condyle as a component of patellofemoral disease: observations at MR imaging

OBJECTIVE

To determine the prevalence of chondromalacia isolated to the anterior margin of the lateral femoral condyle as a component of patellofemoral disease in patients with anterior knee pain and to correlate it with patient demographics, patellar shape, and patellofemoral alignment.

MATERIALS AND METHODS

Retrospective study over a 1-year period reviewing the MR knee examinations of all patients who were referred for assessment of anterior knee pain. Only patients with isolated lateral patellofemoral disease were included. Age, gender, distribution of lateral patellofemoral chondromalacia, and grade of cartilaginous defects were documented for each patient. Correlation between the distribution of lateral patellofemoral chondromalacia and patient demographics, patellar shape, and indices of patellar alignment (femoral sulcus angle and modified Q angle) was then ascertained.

RESULTS

There were 50 patients (22 males, 28 females) with anterior knee pain and isolated patellofemoral disease. The majority of the patients (78 %) had co-existent disease with grade 1 chondromalacia. No significant correlation was found between patients with chondromalacia isolated to the anterior margin of the lateral femoral condyle and age, gender, patellar shape, or modified Q angle (p > 0.05). However, patients with chondromalacia isolated to the anterior margin of the lateral femoral condyle had a shallower femoral sulcus angle (mean 141.8°) compared to the patients with lateral patellar facet disease (mean 133.8°) (p = 0.002).

CONCLUSIONS

A small percentage of patients with anterior knee pain have chondromalacia isolated to the anterior margin of the lateral femoral condyle. This was associated with a shallower femoral sulcus angle.

Risk and causes of paediatric hospital-acquired bacteraemia in Kilifi District Hospital, Kenya: a prospective cohort study

BACKGROUND

In sub-Saharan Africa, community-acquired bacteraemia is an important cause of illness and death in children. Our aim was to establish the magnitude and causes of hospital-acquired (nosocomial) bacteraemia in African children.

METHODS

We reviewed prospectively collected surveillance data of 33,188 admissions to Kilifi District Hospital, Kenya, between April 16, 2002, and Sept 30, 2009. We defined bacteraemia as nosocomial if it occurred 48 h or more after admission. We estimated the per-admission risk, daily rate, effect on mortality, and microbial cause of nosocomial bacteraemia and analysed risk factors by multivariable Cox regression. The effect on morbidity was measured as the increase in hospital stay by comparison with time-matched patients without bacteraemia.

FINDINGS

The overall risk of nosocomial bacteraemia during this period was 5·9/1000 admissions (95% CI 5·2-6·9) but we recorded an underlying rise in risk of 27% per year. The incidence was 1·0/1000 days in hospital (0·87-1·14), which is about 40 times higher than that of community-acquired bacteraemia in the same region. Mortality in patients with nosocomial bacteraemia was 53%, compared with 24% in community-acquired bacteraemia and 6% in patients without bacteraemia. In survivors, nosocomial bacteraemia lengthened hospital stay by 10·1 days (3·0-17·2). Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Acinetobacter spp, group D streptococci, and Pseudomonas aeruginosa accounted for three-quarters of nosocomial infections. Nosocomial bacteraemia was significantly associated with severe malnutrition (hazard ratio 2·52, 95% CI 1·79-3·57) and blood transfusion in children without severe anaemia (4·99; 3·39-7·37).

INTERPRETATION

Our findings show that although nosocomial bacteraemia is rare, it has serious effects on morbidity and mortality, and the microbiological causes are distinct from those of community-acquired bacteraemia. Nosocomial infections are largely unrecognised or undocumented as a health risk in low-income countries, but they are likely to become public health priorities as awareness of their occurrence increases and as other prominent childhood diseases are progressively controlled.

FUNDING

Wellcome Trust.

Relation between falciparum malaria and bacteraemia in Kenyan children: a population-based, case-control study and a longitudinal study

BACKGROUND

Many investigators have suggested that malaria infection predisposes individuals to bacteraemia. We tested this hypothesis with mendelian randomisation studies of children with the malaria-protective phenotype of sickle-cell trait (HbAS).

METHODS

This study was done in a defined area around Kilifi District Hospital, Kilifi, Kenya. We did a matched case-control study to identify risk factors for invasive bacterial disease, in which cases were children aged 3 months to 13 years who were admitted to hospital with bacteraemia between Sept 16, 1999, and July 31, 2002. We aimed to match two controls, by age, sex, location, and time of recruitment, for every case. We then did a longitudinal case-control study to assess the relation between HbAS and invasive bacterial disease as malaria incidence decreased. Cases were children aged 0-13 years who were admitted to hospital with bacteraemia between Jan 1, 1999, and Dec 31, 2007. Controls were born in the study area between Jan 1, 2006, and June 23, 2009. Finally, we modelled the annual incidence of bacteraemia against the community prevalence of malaria during 9 years with Poisson regression.

RESULTS

In the matched case-control study, we recruited 292 cases-we recruited two controls for 236, and one for the remaining 56. Sickle-cell disease, HIV, leucocyte haemozoin pigment, and undernutrition were positively associated with bacteraemia and HbAS was strongly negatively associated with bacteraemia (odds ratio 0·36; 95% CI 0·20-0·65). In the longitudinal case-control study, we assessed data from 1454 cases and 10,749 controls. During the study period, the incidence of admission to hospital with malaria per 1000 child-years decreased from 28·5 to 3·45, with a reduction in protection afforded by HbAS against bacteraemia occurring in parallel (p=0·0008). The incidence of hospital admissions for bacteraemia per 1000 child-years also decreased from 2·59 to 1·45. The bacteraemia incidence rate ratio associated with malaria parasitaemia was 6·69 (95% CI 1·31-34·3) and, at a community parasite prevalence of 29% in 1999, 62% (8·2-91) of bacteraemia cases were attributable to malaria.

INTERPRETATION

Malaria infection strongly predisposes individuals to bacteraemia and can account for more than half of all cases of bacteraemia in malaria-endemic areas. Interventions to control malaria will have a major additional benefit by reducing the burden of invasive bacterial disease.

FUNDING

Wellcome Trust.

Homozygosity and risk of childhood death due to invasive bacterial disease

Background

Genetic heterozygosity is increasingly being shown to be a key predictor of fitness in natural populations, both through inbreeding depression, inbred individuals having low heterozygosity, and also through chance linkage between a marker and a gene under balancing selection. One important component of fitness that is often highlighted is resistance to parasites and other pathogens. However, the significance of equivalent loci in human populations remains unclear. Consequently, we performed a case-control study of fatal invasive bacterial disease in Kenyan children using a genome-wide screen with microsatellite markers.

Methods

148 cases, comprising children aged <13 years who died of invasive bacterial disease, (variously, bacteraemia, bacterial meningitis or neonatal sepsis) and 137 age-matched, healthy children were sampled in a prospective study conducted at Kilifi District Hospital, Kenya. Samples were genotyped for 134 microsatellite markers using the ABI LD20 marker set and analysed for an association between homozygosity and mortality.

Results

At five markers homozygosity was strongly associated with mortality (odds ratio range 4.7 – 12.2) with evidence of interactions between some markers. Mortality was associated with different non-overlapping marker groups in Gram positive and Gram negative bacterial disease. Homozygosity at susceptibility markers was common (prevalence 19–49%) and, with the large effect sizes, this suggests that bacterial disease mortality may be strongly genetically determined.

Conclusion

Balanced polymorphisms appear to be more widespread in humans than previously appreciated and play a critical role in modulating susceptibility to infectious disease. The effect sizes we report, coupled with the stochasticity of exposure to pathogens suggests that infection and mortality are far from random due to a strong genetic basis.

Fraction of all hospital admissions and deaths attributable to malnutrition among children in rural Kenya

BACKGROUND

Malnutrition is common in the developing world and associated with disease and mortality. Because malnutrition frequently occurs among children in the community as well as those with acute illness, and because anthropometric indicators of nutritional status are continuous variables that preclude a single definition of malnutrition, malnutrition-attributable fractions of admissions and deaths cannot be calculated by simply enumerating individual children.

OBJECTIVE

We determined the malnutrition-attributable fractions among children admitted to a rural district hospital in Kenya, among inpatient deaths and among children with the major causes of severe disease.

DESIGN

We analyzed data from children between 6 and 60 mo of age, comprising 13,307 admissions, 674 deaths, 3068 admissions with severe disease, and 562 community controls by logistic regression, using anthropometric z scores as the independent variable and admission or death as the outcome, to calculate the probability of admission as a result of "true malnutrition" for individual cases. Probabilities were averaged to calculate attributable fractions.

RESULTS

Z scores < -3 were insensitive for malnutrition-attributable deaths and admissions, and no single threshold was both specific and sensitive. The overall malnutrition-attributable fraction for in-hospital deaths was 51% (95% CI: 42%, 61%) with midupper arm circumference. Similar malnutrition-attributable fractions were seen for the major causes of severe disease (severe malaria, gastroenteritis, lower respiratory tract infection, HIV, and invasive bacterial disease).

CONCLUSIONS

Despite global improvements, malnutrition still underlies half of the inpatient morbidity and mortality rates among children in rural Kenya. This contribution is underestimated by using conventional clinical definitions of severe malnutrition.

Defining childhood severe falciparum malaria for intervention studies

BACKGROUND

Clinical trials of interventions designed to prevent severe falciparum malaria in children require a clear endpoint. The internationally accepted definition of severe malaria is sensitive, and appropriate for clinical purposes. However, this definition includes individuals with severe nonmalarial disease and coincident parasitaemia, so may lack specificity in vaccine trials. Although there is no "gold standard" individual test for severe malaria, malaria-attributable fractions (MAFs) can be estimated among groups of children using a logistic model, which we use to test the suitability of various case definitions as trial endpoints.

METHODS AND FINDINGS

A total of 4,583 blood samples were taken from well children in cross-sectional surveys and from 1,361 children admitted to a Kenyan District hospital with severe disease. Among children under 2 y old with severe disease and over 2,500 parasites per microliter of blood, the MAFs were above 85% in moderate- and low-transmission areas, but only 61% in a high-transmission area. HIV and malnutrition were not associated with reduced MAFs, but gastroenteritis with severe dehydration (defined by reduced skin turgor), lower respiratory tract infection (clinician's final diagnosis), meningitis (on cerebrospinal fluid [CSF] examination), and bacteraemia were associated with reduced MAFs. The overall MAF was 85% (95% confidence interval [CI] 83.8%-86.1%) without excluding these conditions, 89% (95% CI 88.4%-90.2%) after exclusions, and 95% (95% CI 94.0%-95.5%) when a threshold of 2,500 parasites/mul was also applied. Applying a threshold and exclusion criteria reduced sensitivity to 80% (95% CI 77%-83%).

CONCLUSIONS

The specificity of a case definition for severe malaria is improved by applying a parasite density threshold and by excluding children with meningitis, lower respiratory tract infection (clinician's diagnosis), bacteraemia, and gastroenteritis with severe dehydration, but not by excluding children with HIV or malnutrition.

Effectiveness of Haemophilus influenzae type b Conjugate vaccine introduction into routine childhood immunization in Kenya

CONTEXT

Haemophilus influenzae type b (Hib) conjugate vaccine is not perceived as a public health priority in Africa because data on Hib disease burden and vaccine effectiveness are scarce. Hib immunization was introduced in Kenyan infants in 2001.

OBJECTIVE

To define invasive Hib disease incidence and Hib vaccine program effectiveness in Kenya.

DESIGN, SETTING, AND PATIENTS

Culture-based surveillance for invasive Hib disease at Kilifi District Hospital from 2000 through 2005 was linked to demographic surveillance of 38,000 children younger than 5 years in Kilifi District, Kenya. Human immunodeficiency virus (HIV) infection and Hib vaccination status were determined for children with Hib disease admitted 2002-2005.

INTERVENTIONS

Introduction of conjugate Hib vaccine within the routine childhood immunization program at ages 6, 10, and 14 weeks beginning November 2001.

MAIN OUTCOME MEASURES

Incidence of culture-proven Hib invasive disease before and after vaccine introduction and vaccine program effectiveness.

RESULTS

Prior to vaccine introduction, the median age of children with Hib was 8 months; case fatality was 23%. Among children younger than 5 years, the annual incidence of invasive Hib disease 1 year before and 1 and 3 years after vaccine introduction was 66, 47, and 7.6 per 100,000, respectively. For children younger than 2 years, incidence was 119, 82, and 16 per 100,000, respectively. In 2004-2005, vaccine effectiveness was 88% (95% confidence interval, 73%-96%) among children younger than 5 years and 87% (95% confidence interval, 66%-96%) among children younger than 2 years. Of 53 children with Hib admitted during 2002-2005, 29 (55%) were age-ineligible to have received vaccine, 12 (23%) had not been vaccinated despite being eligible, and 12 (23%) had received 2 or more doses of vaccine (2 were HIV positive).

CONCLUSIONS

In Kenya, introduction of Hib vaccine into the routine childhood immunization program reduced Hib disease incidence among children younger than 5 years to 12% of its baseline level. This impact was not observed until the third year after vaccine introduction.

Salmonella bacteremia in Kenyan children

BACKGROUND

Nontyphoidal Salmonella spp. are among the leading causes of childhood bacteremia in sub-Saharan Africa, yet there are few published clinical series, and the risk factors for acquiring infection are not fully understood.

METHODS

We examined data from 166 cases of nontyphoidal Salmonella bacteremia identified during a large prospective study of bacteremia among all children admitted to a district hospital in Kenya. We also investigated the importance of comorbidities, including current malaria parasitemia, recent malaria (detectable Plasmodium falciparum histidine rich protein 2 in the absence of parasitemia), sickle cell disease, malnutrition and human immunodeficiency virus (HIV) infection.

RESULTS

Nontyphoidal Salmonella bacteremia was associated with severe malnutrition (33% cases), HIV infection (18% cases), a history of illness >7 days, recent hospital admission, splenomegaly, anemia and recent (but not current) malaria but was not associated with diarrhea. Seventy-seven (46%) children with nontyphoidal Salmonella bacteremia fulfilled World Health Organization clinical criteria for a diagnosis of pneumonia. Independent risk factors for death were diarrhea, tachypnea, HIV infection, severe malnutrition, meningitis and young age.

CONCLUSIONS

Clinical diagnosis of invasive nontyphoidal Salmonella infection in African children is difficult without microbiology facilities because clinical features overlap with other conditions. The common risk factors for nontyphoidal Salmonella infection differ from developed countries, with high a prevalence of malnutrition, HIV, malaria and anemia. Children with nontyphoidal Salmonella infection who fulfill World Health Organization clinical criteria for severe pneumonia may receive ineffective therapy in the form of penicillin.

Progressive increase in antimicrobial resistance among invasive isolates of Haemophilus influenzae obtained from children admitted to a hospital in Kilifi, Kenya, from 1994 to 2002

Etest susceptibilities to amoxicillin, chloramphenicol, and trimethoprim-sulfamethoxazole of 240 invasive isolates of Haemophilus influenzae cultured from children in rural Kenya were 66%, 66%, and 38%, respectively. Resistance increased markedly over 9 years and was concentrated among serotype b isolates. In Africa, the increasing cost of treating resistant infections supports economic arguments for prevention through conjugate H. influenzae type b immunization.

Assessment of severe malnutrition among hospitalized children in rural Kenya: comparison of weight for height and mid upper arm circumference

CONTEXT

Severe malnutrition has a high mortality rate among hospitalized children in sub-Saharan Africa. However, reports suggest that malnutrition is often poorly assessed. The World Health Organization recommends using weight for height, but this method is problematic and often not undertaken in practice. Mid upper arm circumference (MUAC) and the clinical sign "visible severe wasting" are simple and inexpensive methods but have not been evaluated in this setting.

OBJECTIVES

To evaluate MUAC and visible severe wasting as predictors of inpatient mortality at a district hospital in sub-Saharan Africa and to compare these with weight-for-height z score (WHZ).

DESIGN, SETTING, AND PARTICIPANTS

Cohort study with data collected at admission and at discharge or death. Predictive values for inpatient death were determined using the area under receiver operating characteristic curves. Participants were children aged 12 to 59 months admitted to a district hospital in rural Kenya between April 1, 1999, and July 31, 2002.

MAIN OUTCOME MEASURE

MUAC, WHZ, and visible severe wasting as predictors of inpatient death.

RESULTS

Overall, 4.4% (359) of children included in the study died while in the hospital. Sixteen percent (1282/8190) of admitted children had severe wasting (WHZ < or =-3) (n = 756), kwashiorkor (n = 778), or both. The areas under the receiver operating characteristic curves for predicting inpatient death did not significantly differ (MUAC: 0.75 [95% confidence interval, 0.72-0.78]; WHZ: 0.74 [95% confidence interval, 0.71-0.77]) (P = .39). Although sensitivity and specificity for subsequent inpatient death were 46% and 91%, respectively, for MUAC less than or equal to 11.5 cm, 42% and 92% for WHZ less than or equal to -3, and 47% and 93% for visible severe wasting, the 3 indices identified different sets of children and were independently associated with mortality. Clinical features of malnutrition were significantly more common among children with MUAC less than or equal to 11.5 cm than among those with WHZ less than or equal to -3.

CONCLUSIONS

MUAC is a practical screening tool that performs at least as well as WHZ in predicting subsequent inpatient mortality among severely malnourished children hospitalized in rural Kenya. Visible severe wasting is also a potentially useful sign at this level, providing appropriate training has been given.

Thyroid disease in a rural Kenyan hospital

OBJECTIVES

To review the spectrum of thyroid pathology diagnoses likely to be encountered by surgeons working in East African hospitals.

DESIGN

A retrospective review of all thyroidectomies performed over a three year period.

SETTING

A rural church based hospital in Kenya.

SUBJECTS

Two hundred and twenty two patients who underwent thyroidectomy over a three year period at Kijabe hospital.

INTERVENTIONS

A simple protocol was used to manage thyroid disease involving history, clinical examination, measurement of TSH and needle aspiration of lesions where appropriate, and excision when clinically indicated.

MAIN OUTCOME MEASURES

Clinical diagnosis, tribe, operation performed, pathology, and complications of surgery.

RESULTS

Two hundred and twenty thyroidectomies were performed. Overall there was a malignancy rate of 11.7% (15 papillary, 11 follicular). The commonest pathological diagnosis was multinodular goitre (47%). Graves' disease was a relatively common diagnosis in this series (13%). The mortality rate was 0.5% and the morbidity rate was 3.6%.

CONCLUSION

Graves' disease is not as uncommon in rural Africa as previously thought. Malignancy is relatively common and there appears to be a change in the papillary to follicular cancer ratio perhaps reflecting widespread iodinisation of salt in Kenya.

Invasive Gram-negative bacilli are frequently resistant to standard antibiotics for children admitted to hospital in Kilifi, Kenya

OBJECTIVES

To determine the pattern of resistance among Gram-negative bacilli causing invasive bacterial disease for the antibiotics that are already in common use in Kilifi, Kenya and for two potential alternatives, ciprofloxacin and cefotaxime. Also, to determine whether prevalence and severity of resistance was increasing over time, to identify patients who are particularly at risk of resistant infections, and to explore which factors are associated with the development of resistance in our setting.

METHODS

We used Etest to study antibiotic susceptibility patterns of 90 Gram-negative bacilli cultured in blood or CSF from paediatric inpatients over 8 years.

RESULTS

Susceptibility to amoxicillin 28%, cefotaxime 95% and ciprofloxacin 99% did not vary significantly with age. Susceptibilities for isolates from children aged less than 14 days were: chloramphenicol, 81%; trimethoprim/sulfamethoxazole, 71%; and gentamicin, 91%. From older children, susceptibilities were: chloramphenicol, 62%; trimethoprim/sulfamethoxazole, 39%; and gentamicin, 73%. Chloramphenicol susceptibility was significantly more common among non-typhi salmonellae than other species (79% versus 53%, P < 0.0005). The combination of gentamicin and chloramphenicol covered 91% of all isolates. The prevalence of resistance did not increase over time and was not more common in patients with HIV or malnutrition. Age was the only clinical feature that predicted resistance.

CONCLUSIONS

Gentamicin or chloramphenicol alone was suboptimal therapy for Gram-negative sepsis, although in this retrospective study, there was no association between resistance and mortality.

Use of clinical syndromes to target antibiotic prescribing in seriously ill children in malaria endemic area: observational study

OBJECTIVES

To determine how well antibiotic treatment is targeted by simple clinical syndromes and to what extent drug resistance threatens affordable antibiotics.

DESIGN

Observational study involving a priori definition of a hierarchy of syndromic indications for antibiotic therapy derived from World Health Organization integrated management of childhood illness and inpatient guidelines and application of these rules to a prospectively collected dataset.

SETTING

Kilifi District Hospital, Kenya.

PARTICIPANTS

11,847 acute paediatric admissions.

MAIN OUTCOME MEASURES

Presence of invasive bacterial infection (bacteraemia or meningitis) or Plasmodium falciparum parasitaemia; antimicrobial sensitivities of isolated bacteria.

RESULTS

6254 (53%) admissions met criteria for syndromes requiring antibiotics (sick young infants; meningitis/encephalopathy; severe malnutrition; very severe, severe, or mild pneumonia; skin or soft tissue infection): 672 (11%) had an invasive bacterial infection (80% of all invasive bacterial infections identified), and 753 (12%) died (93% of all inpatient deaths). Among P falciparum infected children with a syndromic indication for parenteral antibiotics, an invasive bacterial infection was detected in 4.0-8.8%. For the syndrome of meningitis/encephalopathy, 96/123 (76%) isolates were fully sensitive in vitro to penicillin or chloramphenicol.

CONCLUSIONS

Simple clinical syndromes effectively target children admitted with invasive bacterial infection and those at risk of death. Malaria parasitaemia does not justify withholding empirical parenteral antibiotics. Lumbar puncture is critical to the rational use of antibiotics.

Bacteremia among children admitted to a rural hospital in Kenya

BACKGROUND

There are few epidemiologic data on invasive bacterial infections among children in sub-Saharan Africa. We studied every acute pediatric admission to a rural district hospital in Kenya to examine the prevalence, incidence, types, and outcome of community-acquired bacteremia.

METHODS

Between August 1998 and July 2002, we cultured blood on admission from 19,339 inpatients and calculated the incidence of bacteremia on the basis of the population served by the hospital.

RESULTS

Of a total of 1783 infants who were under 60 days old, 228 had bacteremia (12.8 percent), as did 866 of 14,787 children who were 60 or more days of age (5.9 percent). Among infants who were under 60 days old, Escherichia coli and group B streptococci predominated among a broad range of isolates (14 percent and 11 percent, respectively). Among infants who were 60 or more days of age, Streptococcus pneumoniae, nontyphoidal salmonella species, Haemophilus influenzae, and E. coli accounted for more than 70 percent of isolates. The minimal annual incidence of community-acquired bacteremia was estimated at 1457 cases per 100,000 children among infants under a year old, 1080 among children under 2 years, and 505 among children under 5 years. Of all in-hospital deaths, 26 percent were in children with community-acquired bacteremia. Of 308 deaths in children with bacteremia, 103 (33.4 percent) occurred on the day of admission and 217 (70.5 percent) within two days.

CONCLUSIONS

Community-acquired bacteremia is a major cause of death among children at a rural sub-Saharan district hospital, a finding that highlights the need for prevention and for overcoming the political and financial barriers to widespread use of existing vaccines for bacterial diseases.

Indicators of acute bacterial meningitis in children at a rural Kenyan district hospital

OBJECTIVE

Acute bacterial meningitis remains an important cause of death and neurologic sequelae in African children. The clinical features of meningitis are often nonspecific and in this setting may overlap with those of malaria. Early diagnosis and appropriate antibiotic treatment are perhaps the most important steps in management, but published data suggest that fewer than half of the cases of childhood meningitis are identified at first assessment in hospitals in this region. The objective of this study was to identify clinical indicators of acute bacterial meningitis by examining components of the World Health Organization Integrated Management of Childhood Illness (IMCI) referral criteria for meningitis (lethargy, unconsciousness, inability to feed, stiff neck, or seizures) and other symptoms and signs.

METHODS

Kilifi District Hospital, serving approximately 200,000 people in a rural, malaria-endemic area of the Kenyan coast, was studied. A Kenya Medical Research Institute research center is located at the hospital. All pediatric admissions aged > or =60 days between June 2001 and July 2002 were eligible.

RESULTS

A total of 91 (2.0%) of 4582 admissions had meningitis, including 77 (4.0%) of 1929 of those who met the IMCI referral criteria for meningitis at admission (sensitivity: 85%; specificity: 59%). Independent indicators of the presence of meningitis were a bulging fontanel, neck stiffness, cyanosis, impaired consciousness, partial seizures, and seizures outside the febrile convulsions age range. One or more of these indicators was present in 895 (19%) of admissions, 72 (8.0%) of whom had meningitis (sensitivity: 79%; specificity: 80%). Independent indicators of the absence of meningitis were the absence of a history of fever, a history of diarrhea, and a positive malaria slide. The area under the receiver operating characteristic curve for a set of simple screening rules based on the positive indicators identified was 0.88 (95% confidence interval: 0.85-0.92).

CONCLUSIONS

The presence of > or =1 of a bulging fontanel, neck stiffness, cyanosis, impaired consciousness, partial seizures, and seizures outside the febrile convulsions age range is a clear indication for lumbar puncture and/or presumptive treatment. However, careful observation and reassessment may be the only practical way to identify one fifth of meningitis cases in this setting.

Prognostic indicators of early and late death in children admitted to district hospital in Kenya: cohort study

OBJECTIVES

To identify clinical indicators of immediate, early, and late mortality in children at admission to a sub-Saharan district hospital and to develop prognostic scores.

DESIGN

Prospective cohort study.

SETTING

One district hospital in Kenya.

PARTICIPANTS

Children aged over 90 days admitted to hospital from 1 July 1998 to 30 June 2001.

MAIN OUTCOME MEASURES

Prognostic indicators of mortality.

RESULTS

Of 8091 children admitted up to 1 June 2000, 436 (5%) died. Sixty (14%) died within four hours after admission (immediate), 193 (44%) after 4-48 hours (early), and 183 (42%) after 48 hours (late). There were marked differences in the clinical features associated with immediate, early, and late death. Seven indicators (neurological status, respiratory distress (subcostal indrawing or deep breathing), nutritional status (wasting or kwashiorkor), severe anaemia, jaundice, axillary temperature, and length of history) were included in simplified prognostic scores. Data from 4802 children admitted from 1 July 2000 to 30 June 2001 were used to validate the scores. For simplified prognostic scores the areas under the receiver operating characteristic curves were 0.93 (95% confidence interval 0.92 to 0.94), 0.82 (0.80 to 0.83), and 0.82 (0.81 to 0.84) for immediate, early, and late death, respectively.

CONCLUSION

In children admitted to a sub-Saharan hospital, the prognostic indicators of early and late deaths differ but a small number of simple clinical signs predict outcome well.

Management of solitary thyroid nodules in rural Africa

OBJECTIVES

To review a simple protocol for the management of solitary thyroid nodules and to document the spectrum of pathological diagnoses associated with this condition.

DESIGN

A retrospective review of all solitary solid thyroid nodules excised over a three-year period from 1st January 1999 to 31st December 2001.

SETTING

A rural church-based hospital in Kenya.

SUBJECTS

All patients undergoing thyroidectomy for solitary solid thyroid nodule over a three-year period at Kijabe Hospital.

INTERVENTIONS

A simple protocol was used to manage this condition involving history, clinical examination, needle aspiration of the lesion, and excision when clinically indicated.

MAIN OUTCOME MEASURES

Clinical diagnosis, tribe, operation performed, pathology, and complications of surgery.

RESULTS

Eighty-one operations were performed for a solitary thyroid nodule. The most common operations were lobectomy and isthmusectomy. There were two complications--a neck haematoma that required surgery and one recurrent laryngeal nerve injury. The commonest pathological diagnosis was multinodular goitre (42%). There was a 16% malignancy rate with eight papillary carcinomas, five follicular carcinomas, and one hurthle cell carcinoma.

CONCLUSIONS

The simple protocol described gives good results in a rural African hospital. Solitary solid thyroid nodules should be routinely excised due to the 16% malignancy rate in this condition. There is a possibility that there is a shift in the ratio of papillary to follicular carcinomas compared to older African studies and this would be an interesting area for further study.

Acute bacterial meningitis in children admitted to a rural Kenyan hospital: increasing antibiotic resistance and outcome

BACKGROUND

Acute bacterial meningitis (ABM) is an important cause of mortality in Africa, but most studies are based in urban referral hospitals. Poor laboratory facilities make diagnosis difficult, and treatment is limited to inexpensive antibiotics.

METHODS

We retrospectively reviewed data from children admitted with ABM to a Kenyan district hospital from 1994 through 2000. We calculated the minimum incidence in children admitted from a defined area. We also examined the antibiotic susceptibility patterns.

RESULTS

We identified 390 cases (1.3% of all admissions) of whom 88% were <5 years old. The apparent minimum annual incidence in children younger than 5 years of age increased from 120 to 202 per 100,000 between 1995 and 2000 (P < 0.001). Increasing the lumbar punctures performed by including prostrated or convulsing children significantly increased the number of cases detected (P < 0.005). The most common organisms in infants <3 months were streptococci and Enterobacteriaceae. Streptococcus pneumoniae (43.1%) and Haemophilus influenzae (41.9%) were predominant in the postneonatal period. The overall mortality was 30.1%, and 23.5% of survivors developed neurologic sequelae. Chloramphenicol resistance of H. influenzae rose from 8% in 1994 to 80% in 2000 (P < 0.0001) accompanied by an apparent increase in mortality. A short history, impaired consciousness and hypoglycemia were associated with death. Prolonged coma and low cerebrospinal fluid glucose were associated with neurologic sequelae.

CONCLUSION

ABM in rural Kenya is a severe illness with substantial mortality and morbidity. Prognosis could be improved by broadening the criteria for lumbar puncture and use of appropriate antibiotics.

Diagnosis of acute bacterial meningitis in children at a district hospital in sub-Saharan Africa

BACKGROUND

The diagnosis of acute bacterial meningitis in children is difficult in sub-Saharan Africa, because the clinical features overlap with those of other common diseases, and laboratory facilities are inadequate in many areas. We have assessed the value of non-laboratory tests and incomplete laboratory data in diagnosing childhood acute bacterial meningitis in this setting.

METHODS

We prospectively studied 905 children undergoing lumbar puncture at a rural district hospital in Kenya over 1 year. We related microbiological findings and cerebrospinal-fluid (CSF) laboratory measurements to tests that would typically be available at such a hospital.

FINDINGS

Acute bacterial meningitis was proven in 45 children (5.0% [95% CI 3.7-6.6]) and probable in 26 (2.9% [1.9-4.2]). 21 of the 71 cases of proven or probable acute bacterial meningitis had neither neck stiffness nor turbid CSF. In eight of 45 children with proven disease the CSF leucocyte count was less than 10x10(6)/L or leucocyte counting was not possible because of blood-staining. The presence of either a leucocyte count of 50x10(6)/L or more or a CSF/blood glucose ratio of 0.10 or less detected all but two of the 45 children with proven acute bacterial meningitis; these two samples were grossly blood-stained.

INTERPRETATION

The diagnosis of childhood acute bacterial meningitis is likely to be missed in a third of cases at district hospitals in sub-Saharan Africa without adequate and reliable laboratory resources. CSF culture facilities are expensive and difficult to maintain, and greater gains could be achieved with facilities for accurate leucocyte counting and glucose measurement.

Paediatric survival and re-admission risks following hospitalization on the Kenyan coast

The district general hospital (DGH) is a common feature of health service provision in many developing countries. We have used linked demographic and clinical surveillance in a rural community located close to a DGH on the Kenyan coast to define the use and public health significance of essential clinical services provided by it. Of a birth cohort of over 4000 children followed for approximately 6 years, about a third were admitted to hospital at least once. Significantly more children admitted with major infectious diseases such as malaria and acute respiratory tract infections were readmitted with the same condition during the surveillance period than would have been expected by chance. Among surviving admissions, mortality post-discharge was significantly higher than in the cohort which had not been admitted within 3, 6 and 12 months. Most of the patients who died after discharge had been admitted with a diagnosis of gastroenteritis. Most children admitted to the DGH survive hospitalization and the remaining period of childhood. Despite no clinical trial evidence to support the claim, it seems reasonable to assume that in the absence of intensive clinical management provided by a DGH, a significant proportion of these children would not have survived. However, the DGH is able to define a group of at-risk children who re-present with severe complications of infectious disease, and of these several may have underlying conditions not amenable to DGH intervention and continue to have a poor prognosis. Both groups of children represent statistically significant subsets of a rural paediatric community and the future organization and co-ordination of DGH and primary care services need to work in unison to strengthen the service needs of children at risk.

Effect of phenobarbital on seizure frequency and mortality in childhood cerebral malaria: a randomised, controlled intervention study

BACKGROUND

Seizures commonly complicate cerebral malaria and are associated with an increased risk of death and neurological sequelae. We undertook a randomised study to assess the efficacy of intramuscular phenobarbital in preventing seizures in childhood cerebral malaria.

METHODS

Children with cerebral malaria admitted to one hospital in Kilifi, Kenya, were randomly assigned a single intramuscular dose of phenobarbital (20 mg/kg) or identical placebo. Clinical tolerance was assessed at the start of the trial, with particular reference to respiratory depression and hypotension. Seizures were timed and recorded, and treated in a standard way. Plasma phenobarbital concentrations were measured. Analyses were by intention to treat.

FINDINGS

440 children with cerebral malaria were admitted to the hospital; 100 were not recruited to the study. Of the remaining 340, 170 received phenobarbital and 170 placebo. The drug was adequately absorbed and well tolerated. Seizure frequency was significantly lower in the phenobarbital group than in the placebo group (18 [11%] vs 46 [27%] children had three or more seizures of any duration; odds ratio 0.32 [95% CI 0.18-0.58]) but mortality was doubled (30 [18%] vs 14 [8%] deaths; 2.39 [1.28-4.64]). The frequency of respiratory arrest was higher in the phenobarbital group than in the placebo group, and mortality was greatly increased in children who received phenobarbital plus three or more doses of diazepam (odds ratio 31.7 [1.2-814]).

INTERPRETATION

In children with cerebral malaria, phenobarbital 20 mg/kg provides highly effective seizure prophylaxis but is associated with an unacceptable increase in mortality. Use of this dose cannot, therefore, be recommended.

Cerebral malaria versus bacterial meningitis in children with impaired consciousness

Cerebral malaria (CM) and acute bacterial meningitis (ABM) are the two common causes of impaired consciousness in children presenting to hospital in sub-Sahara Africa. Since the clinical features of the two diseases may be very similar, treatment is often guided by the initial laboratory findings. However, no detailed studies have examined the extent to which the laboratory findings in these two diseases may overlap. We reviewed data from 555 children with impaired consciousness admitted to Kilifi District Hospital, Kenya. Strictly defined groups were established based on the malaria slide, cerebrospinal fluid (CSF) leucocyte count and the results of blood and CSF culture and CSF bacterial antigen testing. Our data suggests significant overlap in the initial CSF findings between CM and ABM. The absolute minimum proportions of children with impaired consciousness and malaria parasitaemia who also had definite bacterial meningitis were 4% of all children and 14% of children under 1 year of age. The estimated maximum proportion of all children with impaired consciousness and malaria parasitaemia in whom the diagnosis was dual or unclear was at least 13%. The finding of malaria parasites in the blood of an unconscious child in sub-Saharan Africa is not sufficient to establish a diagnosis of cerebral malaria, and acute bacterial meningitis must be actively excluded in all cases.

Abnormal respiratory patterns in childhood cerebral malaria

Of 295 children with cerebral malaria, 117 (40%) had an abnormal respiratory pattern; 15 children exhibited more than one pattern during their clinical course. Four distinct patterns were seen. (i) Deep breathing (80 children); this was associated with severe metabolic acidosis, and resolved following treatment with intravenous fluids and/or blood. (ii) Hypoventilation with nystagmus and salivation (18 children); simultaneous electroencephalographic recording revealed continuous electrical seizure activity, demonstrating that these children were in subtle status epilepticus; anticonvulsant treatment resulted in return to normal of blood gases and recovery of consciousness. (iii) Hyperventilation with extensor posturing (20 children), which was associated with varying degrees of intracranial hypertension. (iv) Periodic respiration (14 children); all had clinical features suggestive of transtentorial herniation, and died following a respiratory arrest. Abnormal respiratory patterns can alert the clinician to complications of cerebral malaria that require treatment. Recognition of these patterns and rapid initiation of appropriate supportive therapy may help to reduce the high mortality rate of this disease.

Hypoglycaemia on and after admission in Kenyan children with severe malaria

We investigated the pathophysiology of hypoglycaemia in severe malaria in African children, especially the potential importance of glycerol as a substrate for gluconeogenesis, and whether substrate limitation contributes to hypoglycaemia in severe disease. Of 171 children with moderate or severe malaria, 16% were hypoglycaemic on admission, while at least 9% of children with severe malaria treated with quinine and a concurrent 4% dextrose infusion had a definite episode of hypoglycaemia after admission. Blood levels of gluconeogenic precursors are as high (alanine and lactate) or higher (glycerol) in those with either hypoglycaemia on or after admission as they are in children never having an episode of hypoglycaemia. Among children with severe malaria, however, those having a definite episode of hypoglycaemia at some stage are more acidotic and have greater evidence of renal impairment than those who are never hypoglycaemic (mean base excess -14.4 vs. -7.2, p < 0.001, mean creatinine 97 vs. 64, p < 0.001 and mean urea 8.1 vs. 5.8, p = 0.03, respectively). These data do not support a role for reduced gluconeogenic substrate supply in the pathogenesis of hypoglycaemia in severe childhood malaria, but do support the hypothesis that gluconeogenesis is impaired. Commonly-used bedside blood glucose monitoring devices may overestimate blood glucose measurements in the normal range, and paradoxically may also seriously overestimate the frequency of hypoglycaemia.

Intracranial hypertension in Africans with cerebral malaria

The causes of death and neurological sequelae in African children with cerebral malaria are obscure. Intracranial pressure (ICP) was monitored and cerebral perfusion pressure (CPP) calculated in 23 Kenyan children with cerebral malaria. Four children had severe intracranial hypertension (ICP > 40 mm Hg, CPP < 40 mm Hg): two died, one with an ICP of 158 mm Hg and signs of transtentorial herniation, the other one with an ICP of 42 mm Hg and cardiorespiratory arrest. The other two survived with severe neurological sequelae. Nine had intermediate intracranial hypertension (ICP > 20 mm Hg, CPP < 50 mm Hg) and 10 had mild intracranial hypertension (maximum ICP 10-20 mm Hg); all survived without severe sequelae. Mannitol controlled the ICP in children with intermediate intracranial hypertension, but it did not prevent the development of intractable intracranial hypertension in children with severe intracranial hypertension. Intracranial hypertension is a feature of Kenyan children with cerebral malaria and severe intracranial hypertension is associated with a poor outcome.

Deep breathing in children with severe malaria: indicator of metabolic acidosis and poor outcome

Despite the frequent association of respiratory symptoms and signs with malarial morbidity and mortality in sub-Saharan Africa, the value of individual symptoms and signs has rarely been assessed. We have prospectively examined the association of individual clinical findings with the summary diagnosis of respiratory distress, outcome, and the presence of metabolic acidosis in children admitted with severe malaria to a Kenyan district hospital. Respiratory distress was present in 119 of the 350 children included in the study and in 23 of the 30 deaths (relative risk = 6.5, 95% confidence interval = 2.8-14.4). The features of a history of dyspnea, nasal flaring, and indrawing or deep breathing (Kussmaul's respiration) were individually most closely associated with the summary diagnosis of respiratory distress. Of these, deep breathing, which was sensitive (91%) and specific (83%) for the presence of severe metabolic acidosis (base excess < or = -12), is the best candidate sign to represent the prognostically important syndrome of malarial respiratory distress. Therefore, it warrants further prospective evaluation in different clinical settings and areas of different malaria endemicity.

Clinical overlap between malaria and severe pneumonia in Africa children in hospital

Data collected from 200 children admitted to a hospital on the Kenyan coast who met a broad definition of severe acute respiratory infection (ARI) indicated that simple clinical signs alone are unable absolutely to distinguish severe ARI and severe malaria. However, laboratory data showed that marked differences exist in the pathophysiology of unequivocal malaria and unequivocal ARI. Children in the former group had a higher mean oxygen saturation (97 vs. 94, P < 0.001), mean blood urea level (5.3 vs. 1.9 mmol/L, P < 0.001) and geometric mean lactate level (4.5 vs. 2.1 mmol/L, P < 0.001), and lower mean haemoglobin level (5.3 vs. 9.0 g/dL, P < 0.001) and base excess (-9.4 vs. -2.6, P < 0.001) than those in the latter group. Using these discriminatory variables it was estimated that up to 45% of children admitted with respiratory signs indicative of severe ARI probably had malaria as the primary diagnosis. Radiological examination supported this conclusion, indicating that pneumonia characterized by consolidation was uncommon in children with respiratory signs and a high malarial parasitaemia (> or = 10,000/microliters). There is no specific radiological sign of severe malaria. In practice, all children with respiratory signs warranting hospital admission in a malaria endemic area should be treated for both malaria and ARI unless blood film examination excludes malaria. In those with malaria and clinical evidence of acidosis, but no crackles, antibodies may be withheld while appropriate treatment for dehydration and anaemia is given. However, if clinical improvement is not rapid, antibiotics should be started.

An open randomized trial of artemether versus quinine in the treatment of cerebral malaria in African children

We have compared the efficacy of artemether versus quinine as treatment for cerebral malaria in children in an open randomized clinical trial in Kenya. Children admitted to hospital with coma and Plasmodium falciparum parasitaemia were treated with either intramuscular artemether (3.2 mg/kg loading dose followed by 1.6 mg/kg daily) or intravenous quinine (20 mg/kg loading dose followed by 10 mg/kg every 8 h). Both drugs were well tolerated and no significant adverse effect was observed. Parasite clearance times (50% and 90%) were shorter in patients treated with artemether (median times [h], with interquartile ranges in brackets, were: 50%, 7.3 [4.2-12.4] vs. 15.5 [9-22]; 90%, 16.9 [13.2-25] vs. 28.5 [22-35]; P < 0.0001). The total mortality in 160 children with cerebral malaria was 16.25%, with no overall significant difference between the 2 treatment groups. In a subgroup of children with respiratory distress, mortality was higher in those treated with artemether (43.7% vs. 11.1%, P < 0.05). The frequency of neurological sequelae and clinical recovery times were similar in both treatment groups. We conclude that there would currently be no advantage in replacing quinine with artemether for the treatment of cerebral malaria in African children.

Epileptic seizures and malaria in Kenyan children

Between October 1990 and November 1991 data were collected on the frequency, causes, and nature of epileptic seizures in children admitted to the paediatric ward at Kilifi District Hospital, Kenya, from a defined study area. During this period, 1324 children were studied, of whom 15.8% had seizures as part of their illness. Malaria was by far the commonest cause of seizures, accounting for 69.0%; no other single condition caused more than 4.4%. The proportion of respiratory infections complicated by seizures was 4.0% compared to 31.3% for malaria. Only 25% of malaria-related epileptic seizures were associated with cerebral malaria; the remainder were associated with otherwise uncomplicated malaria and, in this group, 84% had complex seizures, with 47% being partial and over 70% repetitive. There was no relationship with fever, with 54% of observed seizures occurring at rectal temperatures below 38 degrees C. The minimum community incidence of complex seizures in association with non-cerebral malaria was 5.8 per 1000 per year. Complex epileptic seizures in association with otherwise uncomplicated malaria are common and may be a significant cause of longer term morbidity in malaria endemic areas.

The management of severe malaria in children: a review

We have attempted to summarise an approach to management of severe malaria from our experience and that of others from published data in this review. This represents our current state of knowledge and practices which may change as research continues in this field. It also represents what we feel should be the minimum aim in treating severe malaria even at district hospital level. It focuses on practical issues encountered when admitting such patients: initial assessment, immediate supportive management, use of transfusion, appropriate anti-malarial treatment and ongoing management.

Indicators of life-threatening malaria in African children

BACKGROUND

About 90 percent of the deaths from malaria are in African children, but criteria to guide the recognition and management of severe malaria have not been validated in them.

METHODS

We conducted a prospective study of all children admitted to the pediatric ward of a Kenyan district hospital with a primary diagnosis of malaria. We calculated the frequency and mortality rate for each of the clinical and laboratory criteria in the current World Health Organization (WHO) definition of severe malaria, and then used logistic-regression analysis to identify the variables with the greatest prognostic value.

RESULTS

We studied 1844 children (mean age, 26.4 months) with a primary diagnosis of malaria. Not included were 18 children who died on arrival and 4 who died of other causes. The mortality rate was 3.5 percent (95 percent confidence interval, 2.7 to 4.3 percent), and 84 percent of the deaths occurred within 24 hours of admission. Logistic-regression analysis identified four key prognostic indicators: impaired consciousness (relative risk, 3.3; 95 percent confidence interval, 1.6 to 7.0), respiratory distress (relative risk, 3.9; 95 percent confidence interval, 2.0 to 7.7), hypoglycemia (relative risk, 3.3; 95 percent confidence interval, 1.6 to 6.7), and jaundice (relative risk, 2.6; 95 percent confidence interval, 1.1 to 6.3). Of the 64 children who died, 54 were among those with impaired consciousness (n = 336; case fatality rate, 11.9 percent) or respiratory distress (n = 251; case fatality rate, 13.9 percent), or both. Hence, this simple bedside index identified 84.4 percent of the fatal cases, as compared with the 79.7 percent identified by the current WHO criteria.

CONCLUSIONS

In African children with malaria, the presence of impaired consciousness or respiratory distress can identify those at high risk for death.

Interobserver variation in respiratory signs of severe malaria

Respiratory abnormalities are common presentations of malaria and acute respiratory tract infection, both of which are major causes of childhood mortality and morbidity in sub-Saharan Africa. Appropriate management depends on accurate assessment of disease severity which for the majority of children must be based on clinical signs alone. Choosing which signs best serve this purpose remains a considerable problem particularly in malaria endemic areas. As part of a prospective study to define clinical signs indicative of life threatening malaria video recordings were used to examine the level of agreement between clinicians for potentially important respiratory signs in 51 children. Overall agreement was good for recession, severe recession, and nasal flaring (kappa = 0.57, 0.50, and 0.60 respectively) and substantial for deep breathing and the summary impression of respiratory distress (kappa = 0.70 and 0.69 respectively). However, within this substantial variation in interpretation was apparent between individual observers from slight to almost perfect agreement (kappa values 0.10-0.92). Video is a useful tool to demonstrate interobserver variation and it may also allow training in recognition of signs and a means of standardising clinical signs between centres.

Halofantrine pharmacokinetics in Kenyan children with non-severe and severe malaria

1. Kenyan children with uncomplicated malaria given oral halofantrine (HF; non-micronised suspension; 8 mg base kg-1 body weight 6 hourly for three doses) showed wide variation in the disposition of HF and desbutylhalofantrine (HFm). 2. Eight Kenyan children with severe (prostrate) falciparum malaria who were receiving intravenous quinine, were given the same HF regimen by nasogastric tube. One patient had undetectable HF and two had undetectable HFm at all times after drug administration. 3. The mean AUC(0,24 h) of HF in prostrate children was half (7.54 compared with 13.10 micrograms ml-1 h) (P = 0.06), and that for HFm one-third (0.84 compared with 2.51 micrograms ml-1 h) (P < 0.05) of the value in children with uncomplicated malaria. 4. Oral HF may be appropriate for some cases of uncomplicated falciparum malaria in Africa, but in patients with severe malaria, the bioavailability of HF and HFm may be inadequate.

Brain swelling and ischaemia in Kenyans with cerebral malaria

Computed tomography was performed on 14 unconscious Kenyan children recovering from cerebral malaria (seven of whom had another scan 12-120 days later) to elucidate the cause of intracranial hypertension and neurological sequelae. Brain swelling, defined as a loss of cerebrospinal fluid spaces, was documented in six children, while a further two had conspicuously small ventricles only. There was severe intracranial hypertension in the two children with definite brain swelling in whom intracranial pressure was monitored. There was no evidence of acute hydrocephalus or vasogenic oedema. Four children with brain swelling also had widespread low density areas suggestive of ischaemic damage. The patterns of damage were not uniform but were consistent with a critical reduction in cerebral perfusion pressure (which was documented in the two in whom this was monitored), hypoglycaemia, or status epilepticus. All four had serious neurological sequelae. These data suggest that brain injury in cerebral malaria may be due in part to secondary systemic and intracranial factors as well as to the direct effect of intravascular sequestration.

Periodicity and space-time clustering of severe childhood malaria on the coast of Kenya

Traditionally malaria epidemiology has focused on factors such as parasite rates and vector dynamics without specific reference to disease. There are limited comprehensive data on malaria as a life-threatening event in African children. We have identified, through hospital surveillance, 581 episodes of severe malaria in residents of a defined area on the Kenya coast over a period of 3 years. This represents an absolute minimum risk of developing severe malaria by the fifth birthday of 1 in 15. The presentation of severe malaria showed marked seasonality, but the timing and magnitude of these fluctuations varied considerably between years. A satellite navigational system was used to define the exact location of the home of each severe malaria case. Space-time clustering of severe malaria was evident in this community. Seasonal peaks in incidence of severe malaria may comprise discrete mini-epidemics. In contrast, parasite rates in the community varied little during the course of the surveillance. The monitoring of disease, as opposed to parasitization, in children may result in more effective targeting of intervention resources.

Towards optimal regimens of parenteral quinine for young African children with cerebral malaria: the importance of unbound quinine concentration

Young African children with severe malaria are given quinine using a regimen designed for Thai adults. We measured quinine in the blood, plasma and plasma water of young children in Kenya after rapid intravenous and intramuscular dosing, and calculated the therapeutic range of unbound quinine. The peak plasma quinine concentration after rapid intravenous dosing was 12.3 +/- 3.7 mg/L (mean +/- SD), 43% higher than in adults given the same regimen previously; this was due to a smaller apparent volume of distribution in the children. The therapeutic range of unbound quinine was calculated as 0.2-2.0 mg/L. Simulations of unbound quinine were made for the standard quinine regimen: unbound drug concentrations rose above the therapeutic range after each dose. The possible risks of quinine-induced visual impairment are discussed. Alternative, lower dose regimens for young African children with severe malaria are described.

Childhood deaths in Africa: uses and limitations of verbal autopsies

The verbal autopsy (VA) is an epidemiological tool that is widely used to ascribe causes of death by interviewing bereaved relatives of children who were not under medical supervision at the time of death. This technique was assessed by comparison with a prospective survey of 303 childhood deaths at a district hospital in Kenya where medically confirmed diagnoses were available. Common causes of death were detected by VA with specificities greater than 80%. Sensitivity of the VA technique was greater than 75% for measles, neonatal tetanus, malnutrition, and trauma-related deaths; however, malaria, anaemia, acute respiratory-tract infection, gastroenteritis, and meningitis were detected with sensitivities of less than 50%. There may have been unwarranted optimism in the ability of VAs to detect some of the major causes of death, such as malaria, in African children. VA used in malaria-specific intervention trials should be interpreted with caution and only in the light of known sensitivities and specificities.