Possible causes of fever among patients with blood smear negative for malaria parasites at Bombo Regional Referral Hospital in Tanga, Tanzania

Background: Due to its diverse and non‐specific clinical presentations, malaria has been associated with most infections causing febrile illnesses. Despite being non-specific, clinical diagnosis is still the main method of malaria diagnosis in most health facilities in sub-Saharan Africa. This study aimed to establish the probable diagnoses among fever cases admitted at Bombo Hospital in north-eastern Tanzania.Methods: This study involved patients admitted in Medical and Paediatric wards with a clinical diagnosis of severe malaria but having negative blood smears (BS) for malaria parasites. Finger prick blood specimens were collected for blood smear microscopy and rapid diagnostic test. Blood and urine cultures were done for all specimens collected.  Some patients were also screened for HIV infection.Results: A total of 227 patients were recruited and the majority (62.1%) were under-five children. Out of the 227 blood specimens cultured, 25 (11.0%) grew different bacteria species. Staphylococcus aureus was the most frequent pathogen (68.0%), followed by S. pneumoniae (24.0%), Salmonella species (4.0%) and Streptococcus pyogenes (4.0%).  Only 7 (3.2%) out of 219 urine specimens cultured showed growth of Escherichia coli, Pseudomonas aeruginosa, S. aureus and Klebsiella pneumoniae. Of the 215 patients screened for HIV, 17 (7.9%) had positive reaction.Conclusion: The findings indicate that S. aureus and S. pneumoniae as the commonest bacteria isolates from blood and P. aeruginosa, S. aureus and K. pneumoniae from urine cultures. These bacteria and HIV should be considered as important contributors to febrile illness cases among patients found with negative BS for malaria parasites

Epidemiology of Malaria in an Area Prepared for Clinical Trials in Korogwe, North-eastern Tanzania.

Site preparation is a pre-requesite in conducting malaria vaccines trials. This study was conducted in 12 villages to determine malariometric indices and associated risk factors, during long and short rainy seasons, in an area with varying malaria transmission intensities in Korogwe district, Tanzania. Four villages had passive case detection (PCD) of fever system using village health workers. Four malariometric cross-sectional surveys were conducted between November 2005 and May 2007 among individuals aged 0-19 years, living in lowland urban, lowland rural and highland strata. A total of 10,766 blood samples were collected for malaria parasite diagnosis and anaemia estimation. Blood smears were stained with Giemsa while haemoglobin level was measured by HaemoCue. Socio-economic data were collected between Jan-Apr 2006. Adjusting for the effect of age, the risk of Plasmodium falciparum parasitaemia was significantly lower in both lowland urban, (OR = 0.26; 95%CI: 0.23-0.29, p < 0.001) and highlands, (OR = 0.21; 95%CI: 0.17-0.25, p < 0.001) compared to lowland rural. Individuals aged 6-9 years in the lowland rural and 4-19 years in both lowland urban and highlands had the highest parasite prevalence, whilst children below five years in all strata had the highest parasite density. Prevalence of splenomegaly and gametocyte were also lower in both lowland urban and highlands than in lowland rural. Anaemia (Hb <11 g/dl) prevalence was lowest in the lowland urban. Availability of PCD and higher socio-economic status (SES) were associated with reduced malaria and anaemia prevalence. Higher SES and use of bed nets in the lowland urban could be the important factors for low malaria infections in this stratum. Results obtained here were used together with those from PCD and DSS in selecting a village for Phase 1b MSP3 vaccine trial, which was conducted in the study area in year 2008

Prospective study on severe malaria among in-patients at Bombo regional hospital, Tanga, north-eastern Tanzania

In Tanzania, malaria is the major cause of morbidity and mortality, accounting for about 30% of all hospital admissions and around 15% of all hospital deaths. Severe anaemia and cerebral malaria are the two main causes of death due to malaria in Tanga, Tanzania. This was a prospective observational hospital-based study conducted from October 2004 to September 2005. Consent was sought from study participants or guardians in the wards. Finger prick blood was collected from each individual for thick and thin smears, blood sugar levels and haemoglobin estimations by Haemocue machine after admission. A total of 494 patients were clinically diagnosed and admitted as cases of severe malaria. Majority of them (55.3%) were children below the age of 5 years. Only 285 out of the total 494 (57.7%) patients had positive blood smears for malaria parasites. Adults aged 20 years and above had the highest rate of cases with fever and blood smear negative for malaria parasites. Commonest clinical manifestations of severe malaria were cerebral malaria (47.3%) and severe anaemia (14.6%), particularly in the under-fives. Case fatality was 3.2% and majority of the deaths occurred in the under-fives and adults aged 20 years and above with negative blood smears. Proper laboratory diagnosis is crucial for case management and reliable data collection. The non-specific nature of malaria symptomatologies limits the use of clinical diagnosis and the IMCI strategy. Strengthening of laboratory investigations to guide case management is recommended