Skip to main content
NCBI home page
NIHPA Author Manuscripts logoLink to NIHPA Author Manuscripts
. Author manuscript; available in PMC: 2012 Jul 24.
Published in final edited form as: Trop Med Int Health. 2011 Apr 7;16(7):830–837. doi: 10.1111/j.1365-3156.2011.02774.x

Invasive bacterial and fungal infections among hospitalized HIV-infected and HIV-uninfected children and infants in northern Tanzania

John A Crump 1,2,3,4, Habib O Ramadhani 3,4, Anne B Morrissey 1, Levina J Msuya 3,4, Lan-Yan Yang 5,6, Shein-Chung Chow 6, Susan C Morpeth 1, Hugh Reyburn 7, Boniface N Njau 3, Andrea V Shaw 1, Helmut C Diefenthal 3,4, John A Bartlett 1,2,3,4, John F Shao 3,4, Werner Schimana 3, Coleen K Cunningham 8, Grace D Kinabo 3,4
PMCID: PMC3227789  NIHMSID: NIHMS318121  PMID: 21470347

Summary

OBJECTIVE

To describe the contribution of paediatric HIV and of HIV co-infections to admissions to a hospital in Moshi, Tanzania, using contemporary laboratory methods.

METHODS

During 1 year, we enrolled consecutively admitted patients aged ≥2 months and <13 years with current or recent fever. All patients underwent standardized clinical history taking, a physical examination and HIV antibody testing; standard aerobic blood cultures and malaria film were also done, and hospital outcome was recorded. Early infant HIV diagnosis by HIV-1 RNA PCR was performed on those aged <18 months. HIV-infected patients also received serum cryptococcal antigen testing and had their CD4-positive T-lymphocyte count and percent determined.

RESULTS

A total of 467 patients were enrolled whose median age was 2 years (range 2 months–13 years); Of those patients, 57.2% were female and 12.2% were HIV-infected. Admission clinical diagnosis of HIV disease was made in 10.7% and of malaria in 60.4%. Of blood cultures, 5.8% grew pathogens; of these 25.9% were Salmonella enterica (including 6 Salmonella Typhi) and 22.2% Streptococcus pneumoniae. Plasmodium falciparum was identified on blood film of 1.3%. HIV infection was associated with S. pneumoniae (odds ratio 25.7, 95% CI 2.8, 234.0) bloodstream infection (BSI), but there was no evidence of an association with Escherichia coli or P. falciparum; Salmonella Typhi BSI occurred only among HIV-uninfected participants. The sensitivity and specificity of an admission clinical diagnosis of malaria were 100% and 40.3%; and for an admission diagnosis of bloodstream infection, they were 9.1% and 86.4%, respectively.

CONCLUSION

Streptococcus pneumoniae is a leading cause of bloodstream infection among paediatric admissions in Tanzania and is closely associated with HIV infection. Malaria was over-diagnosed clinically, whereas invasive bacterial disease was underestimated. HIV and HIV co-infections contribute to a substantial proportion of paediatric febrile admissions, underscoring the value of routine HIV testing.

Keywords: Africa, bacteremia, HIV, paediatrics, Salmonella enterica, Streptococcus pneumoniae

Introduction

Fever is a common presenting feature among children and infants admitted to hospital in sub-Saharan Africa (Petit & van Ginneken 1995). Malaria, bacteremia, or other infectious conditions presenting as a febrile illness account for a large proportion of deaths in sub-Saharan Africa (Bryce et al. 2005), yet the laboratory capacity to make aetiologic diagnosis is often lacking (Archibald & Reller 2001; Petti et al. 2006). Consequently, clinicians often rely on syndromic approaches to patient management (WHO 2000, 2005) and while application of such algorithms improves patient care, a proportion of patients inevitably do not receive specific therapy for potentially life threatening infections (Reyburn et al. 2004). Although malaria is often considered to be the leading life threatening cause of febrile illness in sub-Saharan Africa, malaria transmission intensity varies considerably by location (Hay et al. 2009). Furthermore, recent efforts to expand coverage with insecticide-treated bed nets and switch to more effective malaria treatment regimens have been associated with substantial declines in malaria parasite rates in the community and in the proportion of outpatient visits and hospital admissions because of malaria in a number of countries (WHO 2009; O’Meara et al. 2010).

While routine use of blood cultures is uncommon in sub-Saharan Africa, expanded use of blood culture at a few sentinel sites has highlighted the importance of invasive bacterial disease as a cause of illness and death among children both within and outside the hospital (Campbell et al. 2004; Berkley et al. 2005; Brent et al. 2006; Gordon et al. 2008; Sigauque et al. 2009; Nadjm et al. 2010; Reddy et al. 2010). Patients with invasive bacterial disease frequently are treated empirically with antimalarial drugs without antibacterial therapy, resulting in adverse outcomes (Reyburn et al. 2004). To investigate the aetiology, management and outcomes of febrile illness in an area of low malaria transmission intensity (Hay et al. 2009), we studied paediatric inpatients at a consultant referral hospital in northern Tanzania. The results of a similar study among adults and adolescents are described elsewhere (Crump et al. 2011).

Methods and materials

Setting

Moshi (population >144 000) is the administrative centre of Kilimanjaro Region (population >1.4 million) in northern Tanzania, situated at 890 m above sea level. The climate is characterized by a long rainy period (March–May) and a short rainy period (October–December; National Bureau of Statistics & ORC Macro 2005). Kilimanjaro Christian Medical Centre (KCMC), a consultant referral hospital with 458 inpatient beds serving several regions in northern Tanzania, is an important provider of hospital care to residents of Moshi. In 2008, KCMC admitted 22 099 patients. Neither Haemophilus influenzae type B nor pneumococcal conjugate vaccine was available through the Tanzania expanded programme on immunizations during the study period. The HIV seropre-valence in Tanzania from population-based surveys of adults in 2003–2004 was 7.0% (Mishra et al. 2006).

Participants

Participants were prospectively identified from among paediatric inpatients at KCMC in Moshi, Tanzania, from 17 September 2007 through 25 August 2008. Admitted patients aged from ≥2 months to <13 years, with a history of fever in the past 48 h or an axillary temperature ≥37.5 °C or a rectal temperature of ≥38.0 °C, were eligible to participate in the study. Patients admitted with known malignancy, renal failure, hepatic failure, bone marrow aplasia, trauma or surgery were excluded. A standardized clinical history and a physical examination were performed by a trained clinical officer who was a member of the study team. Provisional admission diagnoses of the usual hospital clinical team were recorded and coded using the International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) codes. After cleansing of the skin with isopropyl alcohol and povidone iodine, blood was drawn for a single aerobic blood culture (4 ml) as well as for complete blood count, examination for blood parasites and HIV antibody testing. The case definition for attribution of febrile illness to malaria for children aged <5 years was ≥1000 asexual parasites/µl and ≥500 parasites/µl for children aged ≥5 years (Chandler et al. 2006). Acute serum, plasma and whole blood were archived on all participants. For patients found to be HIV seropositive, CD4-positive T-lymphocyte count and per cent and serum cryptococcal antigen were also measured. Early infant diagnosis for those aged <18 months was performed by HIV-1 RNA PCR. Urine was collected as soon as possible after admission for detection of urine antimicrobial activity and for antigen detection of Histoplasma capsulatum and Legionella pneumophila serogroup 1. When requested by the hospital clinical team, a chest radiograph was ordered and reported using a standardized form by a radiologist (HCD). A discharge form was completed at the time of discharge from hospital that captured in-hospital management, whether the patient died in hospital, and the discharge diagnoses coded using ICD-10 codes. The results of all study investigations were provided immediately to the hospital clinical team to inform patient management.

Laboratory methods

Complete blood count and differential were performed using the CellDyn 3500 automated haematology analyzer (Abbott Laboratories. Abbott Park, IL, USA) and interpreted using locally established reference ranges (Buchanan et al. 2010). Thick and thin blood films stained with Giemsa were examined for blood parasites by oil immersion microscopy. Parasite density was determined by standard methods (Greenwood & Armstrong 1991).

Blood culture bottles were assessed for volume adequacy by comparing the weight before and after inoculation with blood. Adequate volume was defined as recommended volume of 4 ml ± 20%. BacT/ALERT® paediatric fan (PF) bottles were loaded into the BacT/ALERT® 3D Microbial Detection System (BioMérieux Inc., Durham, NC, USA) where they were incubated for 5 days. Standard methods were used for identifying bloodstream isolates. S. pneumoniae were serotyped by latex agglutination and the Quellung reaction using antisera from Statens Serum Institut, Denmark. Non-typhoidal Salmonella (NTS) were serotyped according to the Kauffmann–White scheme (Grimont & Weill 2007). Antimicrobial susceptibility testing was performed according to the methods of the Clinical Laboratory Standards Institute (CLSI, Wayne, PA, USA), M100-S18, January 2008 (Clinical Laboratories Standards Institute 2008).

HIV-1 antibody testing was performed on whole blood using both the Capillus™ HIV-1/HIV-2 (Trinity Biotech PLC, Bray, Ireland) and Determine™ HIV-1/2 (Abbott Laboratories) rapid HIV antibody tests. The Capillus test was replaced with the SD Bioline HIV-1/2 3.0 (Standard Diagnostics Inc., Kyonggi-do, Korea) on 4 March 2008 after a change in Tanzania Ministry of Health HIV testing guidelines. If rapid tests were discordant, the sample was tested with an ELISA (Vironostika® Uni-Form II plus O Ab; BioMérieux). If the ELISA was negative, no further testing was performed. If the ELISA was positive, a Western blot (Genetic Systems HIV-1 Western Blot kit; Bio-Rad, Hercules, CA, USA) was performed to confirm the result (Mayhood et al. 2008). HIV-1 RNA PCR was performed using the Abbott m2000 system RealTime™ HIV-1 assay (Abbott Laboratories; Crump et al. 2009; Scott et al. 2011). The CD4-positive T-lymphocyte count or per cent was measured using the FACSCalibur™ system (Becton Dickinson, Franklin Lakes, NJ, USA). Cryptococcal antigen was measured using the Latex Cryptococcal Antigen Detection System assay (Immuno-Mycologics, Norman, OK, USA), and cryptococcal antigen titre was determined by twofold dilution until endpoint was achieved.

Urine was tested for Legionella pneumophila serogroup 1 antigen using the Legionella Urinary Antigen Test (Binax Inc., Scarborough, ME, USA). Urine was tested for Histoplasma capsulatum antigen using the MVista™ Histoplasma capsulatum Quantitative Antigen EIA (Miravista Diagnostics, Indianapolis, IN, USA; Connolly et al. 2007). Antimicrobial activity in urine was measured using a modification of the method described by Liu et al. (1999) where Bacillus subtilis ATCC 6633 was substituted for Bacillus stearothermophilus ATCC 7953.

During the study, the laboratory participated successfully in relevant external quality assurance programmes of the College of American Pathologists, the Viral Quality Assurance programme of the AIDS Clinical Trials Group, and the United Kingdom National External Quality Assessment Service.

Statistical analysis

Data were entered using the Cardiff Teleform system (Cardiff Inc., Vista, CA, USA) into an Access database (Microsoft Corp). For continuous responses, analysis of variance was used to assess treatment difference between groups. For categorical data and binary responses, Cochran-Mantel-Haenszel test was performed. Descriptive statistics were used for comparisons of baseline demographics and patient characteristics. Weight for age z-scores (WAZ) were calculated using WHO (WHO) AnthroPlus software (WHO, Geneva, Switzerland) and WHO growth standards. The performance of clinical diagnosis at admission, the WHO manual ‘Management of the child with severe infection or severe malnutrition: guidelines for care at first-referral level in developing countries’ (WHO manual; WHO 2000) for septicaemia, typhoid fever, and suspicion of HIV (WHO 2000), and WHO Integrated Management of Childhood Illness (IMCI) guidelines for malaria were assessed against laboratory findings. For the septicaemia analysis, the following signs were used: fever with no obvious focus of infection; blood film for malaria is negative; no stiff neck or other specific signs of meningitis or a lumbar puncture for meningitis is negative; and signs of systemic upset (e.g., inability to drink or breastfeed, convulsions, lethargy or vomiting everything). For the typhoid fever analysis, the following signs were used: fever (particularly ≥7 days), plus any of the following: diarrhoea or constipation, vomiting, abdominal pain, headache or cough; fever with no obvious focus of infection; no stiff neck or other specific signs of meningitis, or a lumbar puncture for meningitis is negative; signs of systemic upset; and blood smear for malaria is negative. All statistical tests were performed at the 5% level of significance (two-sided) with SPSS 12.0 software (SPSS Inc, Chicago, IL, USA).

Research ethics

This study was approved by the KCMC Research Ethics Committee, the Tanzania National Institute for Medical Research National Research Ethics Coordinating Committee and an Institutional Review Board of Duke University Medical Center.

Results

Over the study period, 1154 patients admitted to the paediatric services of KCMC were screened for eligibility. Of these, 644 (55.8%) met eligibility criteria. Ultimately, 467 (72.5%) could be enrolled into the study. The median age (range) of study participants was 2 years (2 months, 13 years) and 267 (57.2%) were female. The median (range) volume of blood inoculated into PF bottles was 2.9 ml (0.15, 9.35 ml), and 139 (29.8%) were classified as adequately filled. Of enrolled patients, 27 (5.8%) had a clinically important organism isolated from blood culture and 16 (3.4%) had an organism classified as a contaminant isolated. Fifty-seven (12.2%) participants were HIV infected. Of HIV-infected patients, the median (range) CD4-positive T-lymphocyte value was 11% (6–21%) for those aged <12 months, 16% (3–34%) for those aged ≥12 months to <5 years and 205 cells/mm3 (2– 1631 cells/mm3) for those aged ≥5 years of age. Of 425 participants aged ≤10 years, the median (range) WAZ was −0.93 (5.00–6.00); 106 (24.9%) had WAZ <−2 and 49 (11.5%) had WAZ <−3.

Relationship between HIV and invasive infections

The relationship between invasive disease and HIV infection is shown in Table 1. Of 26 invasive infections diagnosed, Plasmodium falciparum, Salmonella Typhi and Streptococcus pneumoniae accounted for 6 (22.2%) each; 2 (7.4%) were because of Cryptococcus neoformans. Of three children aged <5 years with positive malaria films, 2 (66.7%) had ≥1000 asexual parasites/µl. Of three children aged ≥5 years, none had ≥500 parasites/µl. Of six S. pneumoniae bloodstream isolates, one (16.7%) belonged to serotype 1; one (16.7%) to serotype 4; one (16.7%) to serotype 5; one (16.7%) to serotype 6B; and two (33.3%) to serotype 14. The non-typhoidal Salmonella bloodstream isolate was serotype Typhimurium. Of six S. pneumoniae isolates, six (100%) were susceptible to chloramphenicol; six (100%) were susceptible to erythromycin; four (66.7%) were susceptible to penicillin by meningitis breakpoints and two showed intermediate susceptibility; one (16.7%) was susceptible to trimethoprim-sulfamethoxazole (SXT) and the remainder were resistant. Of seven Salmonella enterica, two (28.6%) were susceptible to ampicillin and the remainder were resistant; seven (100%) were susceptible to ceftriaxone and none produced extended-spectrum β-lactamases; three (42.9%) were susceptible to chloramphenicol and the remainder were resistant; two (28.6%) were susceptible to SXT and the remainder were resistant; and seven (100%) were susceptible to ciprofloxacin and none showed decreased ciprofloxacin susceptibility (Crump et al. 2003).

Table 1.

Invasive infections among HIV-infected and HIV-uninfected paediatric participants, KCMC 2007–2008

Participants n (%)
Pathogen All
(n = 398)† 		HIV-infected
(n = 57)		 HIV-uninfected
(n = 341)		 OR (95% CI)
Enterobacteriaceae
    Escherichia coli 3 (0.75) 1 (1.75) 2 (0.59) 3.03 (0.27, 33.94)
    Salmonella Typhi 6 (1.51) 0 (0.00) 6 (1.76) Undefined
    Salmonella non-typhoidal 1 (0.25) 1 (1.75) 0 (0.00) *
Other gram-negative organisms
    Legionella pneumophila serogroup 1‡ 0 (0.00) 0 (0.00) 0 (0.00) *
    Haemophilus influenzae type b 1 (0.25) 0 (0.00) 1 (0.29) *
Gram-positive organisms
    Streptococcus pneumoniae 5 (1.26) 4 (7.02) 1 (0.29) 25.66 (2.81, 234.00)
Yeasts
    Cryptococcus neoformans§ 2 (0.50) 2 (3.51) 0 (0.00) Undefined
    Histoplasma capsulatum 2 (0.50) 1 (1.75) 1 (0.29) 6.07 (0.37, 98.48)
Plasmodia
    Plasmodium falciparum 6 (1.51) 0 (0.00) 6 (1.76) Undefined
    Plasmodium non-falciparum 0 (0.00) 0 (0.00) 0 (0.00) *
Total number of participants with invasive infections** 26 (6.53) 9 (15.79) 17 (4.99) 3.57 (1.51, 8.47)
Open in a new tab
*

Numbers too small to calculate a test statistic.

†

HIV status was unknown for 69 participants.

‡

By urine antigen testing.

§

Of invasive Cryptococcus neoformans diagnoses, all were by serum antigen detection with negative blood culture.

All H. capsulatum diagnoses were by urine antigen detection.

**

No patients had more than one invasive infection confirmed by blood culture and antigen detection.

Antimicrobial use prior to admission

A total of 220 (47.1%) patients reported taking antibacterial drugs during their illness prior to admission to hospital. Of these, 47 (21.4%) reported taking SXT, 53 (24.1%) reported taking amoxicillin and 120 (54.5%) reported taking another antibacterial drug. In addition, 143 (30.6%) patients reported taking antimalarial drugs during their illness and prior to admission to hospital. However, among those whose urine was tested, 154 (33.0%) demonstrated urine antimicrobial activity. Of 105 blood cultures drawn from patients with urine antimicrobial activity, 4 (3.8%) were positive whereas 12 (5.1%) of 236 blood cultures drawn from patients without urine antimicrobial activity were positive (OR = 0.74; 95% CI, 0.23–2.35; P = 0.610).

In-hospital case fatality

Of 464 (99.4%) patients whose hospital outcome was known, 34 (7.3%) died, 2 (0.4%) with invasive infection and 32 (6.8%) without documented invasive infection (P = 0.840). One (0.2%) child with S. pneumoniae BSI died. However, there were no deaths among those with typhoid fever, cryptococcal disease, or malaria. Of HIV-infected participants, 5 (8.8%) died in hospital, against 18 (5.3%) of HIV-uninfected participants (P = 0.460).

Reliability of clinical diagnoses

The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of an admission clinical diagnosis of malaria for the presence of malaria parasites on blood smear was 100%, 40.3%, 3.9% and 100%. The sensitivity, specificity, PPV and NPV of an admission diagnosis of bloodstream infection were 9.1%, 86.4%, 3.2% and 95.0%, respectively. The sensitivity, specificity, PPV, and NPV of an admission diagnosis of HIV infection was 66.7%, 98.8%, 90.0% and 94.6%, respectively.

Diagnostic performance of first-referral level guideline

The sensitivity, specificity, PPV and NPV of the WHO manual for septicaemia (blood culture positive for bacterial pathogen) were 94.1%, 2.5%, 4.4% and 90.0%, respectively, and were 60%, 44.4%, 11.4% and 1.2% for typhoid fever (blood culture positive for Salmonella Typhi). For suspicion of HIV infection, the sensitivity, specificity, PPV and NPV of the guidelines were 86.4%, 44.1% 20.9% and 95%, respectively. The sensitivity, specificity, PPV and NPV of the IMCI guidelines for the diagnosis of malaria (blood film positive for Plasmodium spp) were 70%, 16.1%, 1.9% and 95.8%, respectively.

Appropriateness of WHO manual for antimicrobial management of septicaemia

The WHO manual (WHO 2000) for antimicrobial management of septicaemia recommends the combination of benzylpenicillin and chloramphenicol switching to chloramphenicol and ampicillin if there has been a poor response after 48 h. In settings where antimicrobial resistance is common among Gram-negative bacteria, the use of a third generation cephalosporin is suggested to be appropriate (WHO 2000). Among all bacterial pathogens isolated from the bloodstream, 12 (48%) were resistant to ampicillin, 5 (20%) were resistant to chloramphenicol and 4 (16%) were resistant to both. No resistance to ceftriaxone or ciprofloxacin was identified.

Discussion

We demonstrate that febrile illness is a common presenting feature among paediatric patients admitted to a tertiary hospital in northern Tanzania in an area of low malaria transmission intensity. Evaluation for malaria, HIV, and invasive bacterial and fungal disease confirmed that malaria was uncommon and that a substantial minority of patients were HIV-infected. Pneumococcal disease, often HIV-associated, and Salmonella enterica accounted for a substantial proportion of invasive bacterial disease. The diagnostic tests used in this study failed to identify a laboratory diagnosis for a large majority of patients. Malaria was over-diagnosed and invasive bacterial disease was under-diagnosed clinically. Bacterial pathogens were often resistant to commonly used antimicrobial agents. Despite this, clinical outcomes for those with laboratory-confirmed infections were good. However, a larger proportion of those without a laboratory diagnosis using the tests available in this study died prior to hospital discharge. The high case-fatality rate in the group without a laboratory diagnosis underscores the need for further investigation for both infectious and noninfectious conditions.

As anticipated in a low malaria transmission area, malaria was relatively uncommon among febrile patients enrolled in this study (Hay et al. 2009) and no malaria-associated deaths occurred. Although most participants did not have laboratory evidence of malaria, malaria was a common clinical diagnosis on admission presumably associated with initial over use of antimalarial medications and under treatment of other conditions. This finding supports the recent WHO recommendation to use malaria diagnostic testing in all cases of suspected malaria before treatment (WHO 2010).

Invasive bacterial disease was predominantly caused by S. pneumoniae and Salmonella enterica; cryptococcal disease and histoplasmosis were also indentified. Haemophilus influenzae bloodstream infection was uncommon despite the use of laboratory techniques that would optimize its isolation. Non-malaria bloodstream infection was under-diagnosed clinically, suggesting that antibacterial therapy was under-utilized on admission. While malaria may be excluded using diagnostic tests that are available or could be made widely available in sub-Saharan Africa (WHO 2010), diagnostic tests for invasive bacterial and fungal disease are not widely available at healthcare facilities in sub-Saharan Africa (Archibald & Reller 2001; Petti et al. 2006). In a tertiary hospital setting such as KCMC, treatment of febrile patients without malaria following current guidelines (WHO 2000) would result in substantial over use of antibacterial therapy, illustrating the limitations of empiric treatment strategies. Consistent with many other studies from sub-Saharan Africa, bacterial bloodstream isolates were frequently resistant to the commonly used antimicrobial agents ampicillin, chloramphenicol and SXT (Mandomando et al. 2010; Nadjm et al. 2010; Reddy et al. 2010). Taken together, this evidence suggests that consideration should be given to the reevaluation of recommendations for first-line antimicrobial management of paediatric bacterial sepsis in sub-Saharan Africa (WHO 2000).

Of Salmonella enterica bloodstream isolates, serotype Typhi was much more common than non-typhoidal Salmonella. This pattern of invasive salmonellosis differs from that reported in most other studies in sub-Saharan Africa including studies performed elsewhere in Tanzania (Nadjm et al. 2010), where non-typhoidal Salmonella predominates (Crump et al. 2004; Mweu & English 2008; Morpeth et al. 2009; Reddy et al. 2010). The apparent protective effect of HIV against typhoid fever is consistent with the results of a recent meta-analysis and of a study among adults and adolescents in the same area of Tanzania (Reddy et al. 2010; Crump et al. 2011). This finding raises interesting questions about the epidemiology of invasive salmonellosis in sub-Saharan Africa, including the role of HIV and malaria, that warrant further research (Morpeth et al. 2009; MacKenzie et al. 2010; Levine & Farag 2011).

HIV infection, documented in 12.2% of febrile patients, was often immunologically advanced. HIV was not always identified based on clinical suspicion nor would HIV always have been detected by following clinical guidelines (WHO 2000). Pneumococcal disease and cryptococcal disease were associated with HIV infection, and HIV-infected patients were less likely to be discharged alive from the hospital than those without HIV infection. These findings underscore the benefit of routinely offering HIV testing to hospitalized paediatric patients through provider-initiated testing (WHO/UNAIDS 2007).

More than 90% of enrolled patients had no laboratory diagnosis confirmed by the expanded laboratory evaluations provided by the study. Furthermore, while deaths in hospital were uncommon among those patients with laboratory-confirmed malaria and invasive bacterial and fungal disease, almost 7% of those patients without a laboratory diagnosis died. Although the range and consistent application of laboratory tests performed through this study was greater than that available for routine care, we were not able to make other laboratory evaluations that could have explained some of the deaths. For example, we did not have access to cerebrospinal fluid samples; we did not study respiratory tract samples to support the aetiologic diagnosis of pneumonia; nor did we examine stool in patients with diarrhoea. Furthermore, the sensitivity of a single blood culture is <100% and may be further diminished by the prior antimicrobial exposure common among patients at a tertiary hospital. However, it is also possible that infections beyond those identified by examination of such specimens could have played a role. Evaluation of this patient group for other infectious aetiologies is warranted.

This study had a number of limitations. Bias may have been introduced because of failure to enroll all eligible patients. Because the study was designed before the availability of the WHO pocket book of hospital care of children (WHO 2005), the performance of those guidelines could not be assessed. Furthermore, the study duration of only 1 year did not allow us to assess changes across longer time periods.

In summary, the hospital management of febrile illness in sub-Saharan Africa poses many challenges. Recent recommendations to use malaria diagnostic tests to guide the use of antimalarial medications, if adopted, should lead to reductions in the over-diagnosis of malaria particularly in low transmission intensity areas, such as Moshi. Full implementation of routine provider-initiated HIV testing should contribute to ensuring that infants and children with HIV and associated co-infections receive appropriate care. However, targeting antibacterial treatment to those with the highest risk of invasive bacterial disease is challenging. Whereas current practice in many settings underutilizes antibacterial therapy (Reyburn et al. 2004), following existing guidelines may result in overuse of antibacterial therapy. Expansion of clinical microbiology services and focused research would provide useful evidence to guide policy on targeted and empiric management. Furthermore, a large proportion of paediatric patients without laboratory evidence of malaria or invasive bacterial disease died in hospital. Further research on this group using an expanded range of diagnostic evaluations may contribute to reducing mortality in these children.

Acknowledgements

The authors thank Ahaz T. Kulanga, MBA, for providing administrative support to this study and Pilli M. Chambo, Beata V. Kyara, Beatus A. Massawe, Anna D. Mtei, Godfrey S. Mushi, Lillian E. Ngowi, Flora M. Nkya and Winfrida H. Shirima for reviewing and enrolling study participants. We are grateful to the leadership, clinicians and patients of KCMC for their contributions to this research. We thank Angela Karani, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya, for serotyping S. pneumoniae strains, and Gino R. Micalizzi and John R. Bates, Queensland Health Forensic and Scientific Services, Brisbane, Australia, for assistance with serotyping non-typhoidal Salmonella strains. We thank Inverness Medical for donating Binax® NOW Legionella Urinary Antigen Test kits for the study. We thank Miravista Diagnostics, Indianapolis, Indiana, USA, for performing Histoplasma capsulatum Quantitative Antigen EIA on patient samples. We acknowledge the Hubert-Yeargan Center for Global Health at Duke University for critical infrastructure support for the Kilimanjaro Christian Medical Centre-Duke University Collaboration.

Footnotes

This paper was presented in part at the 58th American Society of Tropical Medicine and Hygiene annual meeting, Washington, DC, 18–22 November 2009, abstract 472. Its content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH, which largely funded the work.

References

  1. Archibald LK, Reller LB. Clinical microbiology in developing countries. Emerging Infectious Diseases. 2001;7:302–305. doi: 10.3201/eid0702.010232. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Berkley JA, Lowe BS, Mwangi I, et al. Bacteremia among children admitted to a rural hospital in Kenya. New England Journal of Medicine. 2005;352:39–47. doi: 10.1056/NEJMoa040275. [DOI] [PubMed] [Google Scholar]
  3. Brent AJ, Ahmed I, Ndiritu M, et al. Incidence of clinically significant bacteraemia in children who present to hospital in Kenya: community-based observational study. Lancet. 2006;367:482–488. doi: 10.1016/S0140-6736(06)68180-4. [DOI] [PubMed] [Google Scholar]
  4. Bryce J, Boschi-Pinto C, Shibuya K, Black RE the WHO Child Health Epidemiology Reference Group. WHO estimates of the causes of death in children. Lancet. 2005;365:1147–1152. doi: 10.1016/S0140-6736(05)71877-8. [DOI] [PubMed] [Google Scholar]
  5. Buchanan AM, Muro FJ, Gratz J, et al. Establishment of haematological and immunological reference values for healthy Tanzania children in the Kilimanjaro Region. Tropical Medicine and International Health. 2010;15:1011–1021. doi: 10.1111/j.1365-3156.2010.02585.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Campbell JD, Kotloff KL, Sow SO, et al. Invasive pneumococcal infections among hospitalized children in Bamako, Mali. The Pediatric Infectious Disease Journal. 2004;23:642–649. doi: 10.1097/01.inf.0000130951.85974.79. [DOI] [PubMed] [Google Scholar]
  7. Chandler CIR, Drakeley CJ, Reyburn H, Carneiro I. The effect of altitude on parasite density case definitions for malaria in northeastern Tanzania. Tropical Medicine and International Health. 2006;11:1178–1184. doi: 10.1111/j.1365-3156.2006.01672.x. [DOI] [PubMed] [Google Scholar]
  8. Clinical Laboratories Standards Institute. CLSI document M100-S18. Wayne, PA: Clinical Laboratories Standards Institute; 2008. Performance Standards for Antimicrobial Susceptibility Testing: 18th Informational Supplement. [Google Scholar]
  9. Connolly PA, Durkin MM, LeMonte AM, Hackett EJ, Wheat JL. Detection of Histoplasma antigen by a quantitative enzyme immunoassay. Clinical and Vaccine Immunology. 2007;14:1587–1591. doi: 10.1128/CVI.00071-07. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Crump JA, Barrett TJ, Nelson JT, Angulo FJ. Reevaluating fluoroquinolone breakpoints for Salmonella enterica serotype Typhi and for non-Typhi salmonellae. Clinical Infectious Diseases. 2003;37:75–81. doi: 10.1086/375602. [DOI] [PubMed] [Google Scholar]
  11. Crump JA, Luby SP, Mintz ED. The global burden of typhoid fever. Bulletin of the World Health Organization. 2004;82:346–353. [PMC free article] [PubMed] [Google Scholar]
  12. Crump JA, Scott LE, Msuya E, et al. Evaluation of the Abbott m2000rt RealTime HIV-1 assay with manual sample preparation compared with the ROCHE COBAS AmpliPrep/AMPLICOR HIV-1 MONITOR 1.5 using specimens from East Africa. Journal of Virological Methods. 2009;162:218–222. doi: 10.1016/j.jviromet.2009.08.013. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Crump JA, Ramadhani HO, Morrissey AB, et al. Invasive bacterial and fungal infections among hospitalized HIV-infected and HIV-uninfected adults and adolescents in northern Tanzania. Clinical Infectious Diseases. 2011;52:341–348. doi: 10.1093/cid/ciq103. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Gordon MA, Graham SM, Walsh AL, et al. Epidemics of invasive Salmonella enterica serovar Enteritidis and S. enterica serovar Typhimurium infection associated with multidrug resistance among adults and children in Malawi. Clinical Infectious Diseases. 2008;46:963–969. doi: 10.1086/529146. [DOI] [PubMed] [Google Scholar]
  15. Greenwood BM, Armstrong JRM. Comparison of two simple methods for determining malaria parasite density. Transactions of the Royal Society of Tropical Medicine and Hygiene. 1991;85:186–188. doi: 10.1016/0035-9203(91)90015-q. [DOI] [PubMed] [Google Scholar]
  16. Grimont PAD, Weill F-X. In: Antigenic Formulae of the Salmonella Serovars. 9th edn. WHO Collaborating Centre for Reference and Research on Salmonella, editor. Paris, France: Institut Pasteur; 2007. [Google Scholar]
  17. Hay SI, Guerra CA, Gething PW, et al. A world malaria map: Plasmodium falciparum endemicity in 2007. PLoS Medicine. 2009;6 doi: 10.1371/journal.pmed.1000048. e1000048. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Levine MM, Farag TH. Invasive Salmonella infections and HIV in northern Tanzania. Clinical Infectious Diseases. 2011;52:349–351. doi: 10.1093/cid/ciq109. [DOI] [PubMed] [Google Scholar]
  19. Liu Y-C, Huang WK, Huang TS, Kunin CM. Detection of antimicrobial activity in urine for epidemiologic studies of antibiotic use. Journal of Clinical Epidemiology. 1999;52:539–545. doi: 10.1016/s0895-4356(99)00027-x. [DOI] [PubMed] [Google Scholar]
  20. MacKenzie G, Ceesay SJ, Hill PC, et al. A decline in the incidence of invasive non-typhoidal Salmonella infection in the Gambia temporally associated with a decline in malaria infection. PLoS One. 2010;5 doi: 10.1371/journal.pone.0010568. e10568. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Mandomando I, Sigauque B, Morais L, et al. Antimicrobial drug resistance trends in bacteremia isolates in a rural hospital in southern Mozambique. American Journal of Tropical Medicine and Hygiene. 2010;83:152–157. doi: 10.4269/ajtmh.2010.09-0578. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Mayhood MK, Afwamba IA, Odhiambo CO, et al. Validation, performance under field conditions, and cost-effectiveness of Capillus HIV-1/HIV-2 and Determine HIV-1/2 rapid human immunodeficiency virus antibody assays using sequential and parallel testing algorithms in Tanzania. Journal of Clinical Microbiology. 2008;46:3946–3951. doi: 10.1128/JCM.01045-08. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Mishra V, Vaessen M, Boerma JT, et al. HIV testing in national population-based surveys: experience from the Demographic and Health Surveys. Bulletin of the World Health Organization. 2006;84:537–545. doi: 10.2471/blt.05.029520. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Morpeth SC, Ramadhani HO, Crump JA. Invasive non-Typhi Salmonella disease in Africa. Clinical Infectious Diseases. 2009;49:606–611. doi: 10.1086/603553. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Mweu E, English M. Typhoid fever in children in Africa. Tropical Medicine and International Health. 2008;13:1–9. doi: 10.1111/j.1365-3156.2008.02031.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Nadjm B, Amos B, Mtove G, et al. WHO guidelines for antimicrobial treatment in children admitted to hospital in an area of intense Plasmodium falciparum transmission: prospective study. BMJ. 2010;340 doi: 10.1136/bmj.c1350. c1350. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. National Bureau of Statistics & ORC Macro. Tanzania Demographic and Health Survey 2004–05. In: National Bureau of Statistics & ORC Macro, editor. Dar es Salaam: National Bureau of Statistics & ORC Macro; 2005. [Google Scholar]
  28. O’Meara WP, Mangeni JN, Steketee R, Greenwood B. Changes in the burden of malaria in sub-Saharan Africa. The Lancet Infectious Diseases. 2010;10:545–555. doi: 10.1016/S1473-3099(10)70096-7. [DOI] [PubMed] [Google Scholar]
  29. Petit PL, van Ginneken JK. Analysis of hospital records in four African countries 1975–1990, with emphasis on infectious diseases. The Journal of Tropical Medicine and Hygiene. 1995;98:217–227. [PubMed] [Google Scholar]
  30. Petti CA, Polage CR, Quinn TC, et al. Laboratory medicine in Africa: a barrier to effective health care. Clinical Infectious Diseases. 2006;42:377–382. doi: 10.1086/499363. [DOI] [PubMed] [Google Scholar]
  31. Reddy EA, Shaw AV, Crump JA. Community acquired bloodstream infections in Africa: a systematic review and meta-analysis. The Lancet Infectious Diseases. 2010;10:417–432. doi: 10.1016/S1473-3099(10)70072-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Reyburn H, Mbatia R, Drakeley C, et al. Overdiagnosis of malaria in patients with severe febrile illness in Tanzania: a prospective study. BMJ. 2004;329:1212–1215. doi: 10.1136/bmj.38251.658229.55. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Scott LE, Crump JA, Msuya E, et al. Abbott RealTime HIV-1 m2000rt viral load testing: manual extraction versus the automated m2000sp extraction. Journal of Virological Methods. 2011;172:78–80. doi: 10.1016/j.jviromet.2010.12.006. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Sigauque B, Roca A, Mandomando I, et al. Community-acquired bacteremia among children admitted to a rural hospital in Mozambique. The Pediatric Infectious Disease Journal. 2009;28:108–113. doi: 10.1097/INF.0b013e318187a87d. [DOI] [PubMed] [Google Scholar]
  35. WHO. Geneva: WHO; 2000. Management of the Child with a Serious Infection or Severe Malnutrition: Guidelines for Care at the First-Referral Level in Developing Countries. [Google Scholar]
  36. WHO. Geneva: WHO; 2005. Pocket Book of Hospital Care for Children: Guidelines for the Management of Common Illnesses with Limited Resources. [Google Scholar]
  37. WHO. Geneva: WHO; 2009. World Malaria Report 2009. [Google Scholar]
  38. WHO. 2nd edn. Geneva: WHO; 2010. Guidelines for the Treatment of Malaria. [Google Scholar]
  39. WHO/UNAIDS. Geneva: WHO; 2007. Guidance on Provider-Initiated HIV Testing and Counseling in Healthcare Facilities. [Google Scholar]

RESOURCES