Antibiotic prescribing practice in management of cough and/or diarrhoea in Moshi Municipality, Northern Tanzania: cross-sectional descriptive study

Introduction: The increase in resistance of many pathogens to currently available antibiotics has been recognized as life-threatening problem.The development of drug resistance is promoted by irrational prescribing behavior. Inappropriate use of antibiotics is attributed by overprescription,inadequate dosage and use for non-bacterial infections. The purpose of this study was to assess antibiotic prescribing practices in the management of diarrhoea and cough among children attending hospitals in Moshi municipal, Tanzania.Methods: We conducted a cross-sectional descriptive hospital based study, from September 2010 to March 2011. All children presenting with diarrhoea and cough, aged between one month and 5years attended at the two hospitals were enrolled. Data were collected by a standard questionnaire. Information on the prescribed drugs was obtained from patient files. Results: A total of 384 children were enrolled. Of these, 326 (84.9%) received antibiotics; common prescribed antibiotics were penicillins, sulphonamides, aminoglycosides and macrolides. Eighty percent of children with acute watery diarrhoea and 68.9% with common cold were given antibiotics inappropriately. Inappropriate antibiotic prescription was significantly associated with prescriber being a clinical officer and assistant medical officer, and child having diarrhoea. Inappropriate antibiotic dosage was significantly occurred when prescriber was clinical officer with reference to medical officer. Conclusion: This study observed a high antibiotic prescription rate by clinicians and treatment guidelines for management of patients who presented with cough and/or diarrhoea are followed. Continuing  professional development programmes for clinicians on prescription would help in reducing irrational prescribing practices.Key words: Antibiotics use, irrational prescribing, antibiotic prescribing, pneumonia, cough, diarrhea, under-fiv

Asymptomatic Plasmodium falciparum malaria and gametocyte carriage are common in Coastal Kenya

Adequate malaria diagnosis and treatment remain a major problem in rural sub Saharan Africa. Molecular parasite detection has shown that submicroscopic Plasmodium falciparum asexual and gametocytes are common in patients, and can infect mosquitoes in low endemic areas. The significance of the infectious reservoir of malaria in the general population remains unknown. In this study we investigated submicroscopic asexual parasitaemia and gametocytaemia in inhabitants of areas of hypo-endemic and seasonal malaria in which no molecular analysis on malaria survey has been done before. Cross-sectional stuies during the staging of two clinical trials clinical trial in Mokowe and Lamu, Coastal Kenya were conducted in the dry and wet seasons of 2010. Finger prick blood samples used to determine the prevalence of Plasmodium falciparum parasites by microscopy, Fluorescence In-situ hybridization (FISH), rapid diagnostic test and real time nucleic acid sequence-based amplification (QT-NASBA). A total of 450 individuals participated in the surveys of whom, 2.7% had microscopically confirmed asexual parasites while 2.4% had gametocytes. In contrast, FISH revealed that 8.9% (29/327) and QT-NASBA 24.6% (59/240) of the individuals harbored asexual parasites and 29.2% (70/240) gametocytes. There were a few cases of mixed infection with Plasmodium malariae, 1.8% (8/ 450) by microscopy and 4% (13/327) by FISH. No age dependency or seasonality was observed in the submicroscopic parasite carriage. In conclusion, molecular detection techniques disclose that carriage of submicroscopic asexual parasite and gametocyte is relatively common in these low transmission areas and that submicroscopic gametocytaemia is likely to be responsible for maintaining malaria transmission in the study area.Keywords: submicroscopic, gametocytaemia, FISH, rapid diagnostic test, QT-NASBAAfr J Health Sci. 2013; 26:314-32

Malaria diagnostic testing and treatment practices in three different Plasmodium falciparum transmission settings in Tanzania: before and after a government policy change

BACKGROUND: Patterns of decreasing malaria transmission intensity make presumptive treatment of malaria an unjustifiable approach in many African settings. The controlled use of anti-malarials after laboratory confirmed diagnosis is preferable in low endemic areas. Diagnosis may be facilitated by malaria rapid diagnostic tests (RDTs). In this study, the impact of a government policy change, comprising the provision of RDTs and advice to restrict anti-malarial treatment to RDT-positive individuals, was assessed by describing diagnostic behaviour and treatment decision-making in febrile outpatients <10 years of age in three hospitals in the Kagera and Mwanza Region in northern Tanzania. METHODS: Prospective data from Biharamulo and Rubya Designated District Hospital (DDH) were collected before and after policy change, in Sumve DDH no new policy was implemented. Diagnosis of malaria was confirmed by RDT; transmission intensity was evaluated by a serological marker of malaria exposure in hospital attendees. RESULTS: Prior to policy change, there was no evident association between the actual level of transmission intensity and drug-prescribing behaviour. After policy change, there was a substantial decrease in anti-malarial prescription and an increase in prescription of antibiotics. The proportion of parasite-negative individuals who received anti-malarials decreased from 89.1% (244/274) to 38.7% (46/119) in Biharamulo and from 76.9% (190/247) to 10.0% (48/479) in Rubya after policy change. CONCLUSION: This study shows that an official policy change, where RDTs were provided and healthcare providers were advised to adhere to RDT results in prescribing drugs can be followed by more rational drug-prescribing behaviour. The current findings are promising for improving treatment policy in Tanzanian hospitals

Influence of infection on malaria-specific antibody dynamics in a cohort exposed to intense malaria transmission in northern Uganda.

The role of submicroscopic infections in modulating malaria antibody responses is poorly understood and requires longitudinal studies. A cohort of 249 children ≤5 years of age, 126 children between 6 and 10 years and 134 adults ≥20 years was recruited in an area of intense malaria transmission in Apac, Uganda and treated with artemether/lumefantrine at enrolment. Parasite carriage was determined at enrolment and after 6 and 16 weeks using microscopy and PCR. Antibody prevalence and titres to circumsporozoite protein, apical membrane antigen-1 (AMA-1), merozoite surface protein-1 (MSP-119 ), merozoite surface protein-2 (MSP-2) and Anopheles gambiae salivary gland protein 6 (gSG6) were determined by ELISA. Plasmodium falciparum infections were detected in 38·1% (194/509) of the individuals by microscopy and in 57·1% (284/493) of the individuals by PCR at enrolment. Antibody prevalence and titre against AMA-1, MSP-119 , MSP-2 and gSG6 were related to concurrent (sub-)microscopic parasitaemia. Responses were stable in children who were continuously infected with malaria parasites but declined in children who were never parasitaemic during the study or were not re-infected after treatment. These findings indicate that continued malaria infections are required to maintain antibody titres in an area of intense malaria transmission

Optimal timing of primaquine to reduce Plasmodium falciparum gametocyte carriage when co-administered with artemether-lumefantrine.

BACKGROUND: Primaquine is an important gametocytocidal drug that is combined with conventional malaria treatment for prevention of Plasmodium falciparum malaria transmission. Primaquine has been administered together on the first or the last day of conventional treatment but the impact of primaquine timing has never been examined. This study aimed to assess safety, efficacy and optimal timing of single full-dose (0.75 mg/kg) primaquine when added to a standard 6-dose regimen of artemether-lumefantrine (AL). METHODS: In an individual-level randomized controlled trial, enrolled participants who were G6PD normal and had uncomplicated P. falciparum malaria were randomly assigned to receive: AL only; AL and a single 0.75 mg/kg primaquine dose on the first day of AL (day 1); or AL and single 0.75 mg//kg primaquine on the last day of AL (day 3). On days 2, 3, 4, 8, 11 and 15, gametocytes were assessed and quantified by microscope and quantitative nuclear acid sequence based quantification (QT-NASBA). RESULTS: Overall, 111 participants aged between 3 and 17 years were randomly allocated to receive AL only (36) or combined with primaquine on day 1 (38), or primaquine on day 3 (37). Day 4 gametocyte prevalence in AL?+?day 1 primaquine was half the level seen in either AL?+?day 3 primaquine or AL only arm (11% [4/35] vs 26% [8/31] and 27% [8/30], respectively) albeit not statistically significant. A similar trend of lower gametocyte in the AL?+?day 1 primaquine verses AL?+?day 3 primaquine or AL only arm was observed in mean gametocyte density. Mean (sd) haemoglobin level in AL?+?day 3 primaquine arm recovered from -0.42(1.2) g/dl on day 2 to 0.35 (1.5) g/dl on day 15 of follow up. This was not the case in AL only and AL?+?day 1 primaquine arms during the same follow-up period, although the difference was not statistically significant (p?=?318). No serious adverse events reported in the study. Across arms, 23% (26/111) of participants reported a total of 31 mild adverse events and the difference was not statistically significant (p?=?0.477). CONCLUSION: Primaquine administration on the first day of AL is well tolerated and as safe as later administration. Whilst the World Health Organization currently recommends a lower dose of primaquine (0.25 mg/kg), the findings are supportive of early primaquine administration when combined with artemisinin-combination therapy. ClinicalTrials.gov Registration NCT01906788

Gametocytes: insights gained during a decade of molecular monitoring

In vertebrate hosts, malaria parasites produce specialized male and female sexual stages (gametocytes). Soon after being taken up by a mosquito, gametocytes rapidly produce gametes and, once mated, they infect their vector and can be transmitted to new hosts. Despite being the parasite stages that were first identified (over a century ago), gametocytes have remained elusive, and basic questions remain concerning their biology. However, the postgenomic era has substantiated information on the specialized molecular machinery of gametocytogenesis and expedited the development of molecular tools to detect and quantify gametocytes. The application of such highly sensitive and specific tools has opened up novel approaches and provided new insights into gametocyte biology. Here, we review the discoveries made during the past decade, highlight unanswered questions and suggest new directions

Overuse of artemisinin-combination therapy in Mto wa Mbu (river of mosquitoes), an area misinterpreted as high endemic for malaria

BACKGROUND: Adequate malaria diagnosis and treatment remain major difficulties in rural sub-Saharan Africa. These issues deserve renewed attention in the light of first-line treatment with expensive artemisinin-combination therapy (ACT) and changing patterns of transmission intensity. This study describes diagnostic and treatment practices in Mto wa Mbu, an area that used to be hyperendemic for malaria, but where no recent assessments of transmission intensity have been conducted. METHODS: Retrospective and prospective data were collected from the two major village health clinics. The diagnosis in prospectively collected data was confirmed by microscopy. The level of transmission intensity was determined by entomological assessment and by estimating sero-conversion rates using anti-malarial antibody responses. RESULTS: Malaria transmission intensity by serological assessment was equivalent to 40% of outpatients attending the clinics in 2006-2007 were diagnosed with malaria. Prospective data demonstrated a very high overdiagnosis of malaria. Microscopy was unreliable with < 1% of slides regarded as malaria parasite-positive by clinic microscopists being confirmed by trained research microscopists. In addition, many 'slide negatives' received anti-malarial treatment. As a result, 99.6% (248/249) of the individuals who were treated with ACT were in fact free of malaria parasites. CONCLUSION: Transmission intensity has dropped considerably in the area of Mto wa Mbu. Despite this, most fevers are still regarded and treated as malaria, thereby ignoring true causes of febrile illness and over-prescribing ACT. The discrepancy between the perceived and actual level of transmission intensity may be present in many areas in sub-Saharan Africa and calls for greater efforts in defining levels of transmission on a local scale to help rational drug-prescribing behaviour