Evaluation of surveillance for surgical site infections in Thika Hospital, Kenya.

BACKGROUND: In low-income countries, surgical site infections (SSIs) are a very frequent form of hospital-acquired infection. Surveillance is an important method for controlling SSI but it is unclear how this can best be performed in low-income settings. AIM: To examine the epidemiological characteristics of various components of an SSI surveillance programme in a single Kenyan hospital. METHODS: The study assessed the inter-observer consistency of the surgical wound class (SWC) and American Society of Anesthesiologists (ASA) scores using the kappa statistic. Post-discharge telephone calls were evaluated against an outpatient clinician review 'gold standard'. The predictive value of components of the Centers for Disease Control and Prevention - National Healthcare Safety Network (CDC-NHNS) risk index was examined in patients having major obstetric or gynaecological surgery (O&G) between August 2010 and February 2011. FINDINGS: After appropriate training, surgeons and anaesthetists were found to be consistent in their use of the SWC and ASA scores respectively. Telephone calls were found to have a sensitivity of 70% [95% confidence interval (CI): 47-87] and a specificity of 100% (95% CI: 95-100) for detection of post-discharge SSI in this setting. In 954 patients undergoing major O&G operations, the SWC score was the only parameter in the CDC-NHNS risk index model associated with the risk of SSI (odds ratio: 4.00; 95% CI: 1.21-13.2; P = 0.02). CONCLUSIONS: Surveillance for SSI can be conducted in a low-income hospital setting, although dedicated staff, intensive training and local modifications to surveillance methods are necessary. Surveillance for post-discharge SSI using telephone calls is imperfect but provides a practical alternative to clinic-based diagnosis. The SWC score was the only predictor of SSI risk in O&G surgery in this context.

The Biomolecular Interaction Network Database and related tools 2005 update.

The Biomolecular Interaction Network Database (BIND) (http://bind.ca) archives biomolecular interaction, reaction, complex and pathway information. Our aim is to curate the details about molecular interactions that arise from published experimental research and to provide this information, as well as tools to enable data analysis, freely to researchers worldwide. BIND data are curated into a comprehensive machine-readable archive of computable information and provides users with methods to discover interactions and molecular mechanisms. BIND has worked to develop new methods for visualization that amplify the underlying annotation of genes and proteins to facilitate the study of molecular interaction networks. BIND has maintained an open database policy since its inception in 1999. Data growth has proceeded at a tremendous rate, approaching over 100 000 records. New services provided include a new BIND Query and Submission interface, a Standard Object Access Protocol service and the Small Molecule Interaction Database (http://smid.blueprint.org) that allows users to determine probable small molecule binding sites of new sequences and examine conserved binding residues.

Mitogenic activities in African traditional herbal medicines (Part II).

Mitogenic activities in African traditional herbal medicines were examined on human peripheral blood lymphocytes and mouse spleen cells using protein fractions obtained from their extracts by precipitation with ammonium sulfate. Target specificity for these mitogens was investigated by using isolated T cells and lymphocytes from athymic nude mice. Among 20 plants investigated, potent mitogenic activities for both human and mouse lymphocytes were found in 7 plants: Monanthotaxis sp. (Annonaceae), Uvaria lucida (Annonaceae), Maytenus buchananii (Celastraceae), Lonchocarpus bussei (Leguminosae), Phytolacca dodecandra (Phytolaccaceae), Phytolacca octandra (Phytolaccaceae), and Toddalia asiatica (Rutaceae). The U. lucida stem demonstrated the highest activity among all and induced mitogenesis both in human and mouse isolated T cells, but not in lymphocytes from athymic nude mice.

Origin of blood meals in indoor and outdoor resting malaria vectors in western Kenya.

Blood meals were obtained from indoor and outdoor resting malaria vectors in three villages of western Kenya and tested by sandwich ELISA to determine host preferences and their human blood index (HBI). Anopheles gambiae s.s. collected indoors at Kisian village had a HBI of 0.97 while that of Anopheles arabiensis collected at Ahero was 0.23. However, the HBI of A. arabiensis varied depending on the availability of outdoor resting shelters. Most female A. arabiensis (98.9%) collected outdoors in granaries at Ahero had fed on cattle. Indoor-collected female Anopheles funestus had mainly fed on people (93.0%), but taken at least some of their blood (20.2%) from cattle. Although small numbers of A. arabiensis fed on sheep or goats and birds, none of the female A. gambiae s.s. and A. funestus tested had fed on these hosts. The absence of human-fed A. arabiensis in outdoor shelters indicated that exiting after feeding, a behaviour pattern that mitigates indoor insecticidal spraying, is not prevalent in this species in western Kenya.

Cardiovascular risk factor profiles in mild to moderate hypertensives seen at Kenyatta National Hospital.

Sixty newly diagnosed adult patients with mild to moderate essential hypertension were assessed to determine their cardiovascular risk factor profiles. Detailed history and physical examinations were done. Resting 12-lead ECG was done and serum levels of uric acid, fasting cholesterol, and fasting glucose were determined. Twenty nine patients had hypertension and two or more cardiovascular risk factors. The most prevalent cardiovascular risk factors other than hypertension were electro-cardiovascular left ventricular hypertrophy (31.7%), obesity (28.3%) and hypercholesterolaemia (28.3%). About a half of these patients (48.3%) can be classified as high risk hypertensives. This calls for aggressive management of cardiovascular risk factors as a whole and not just hypertension alone if we are to reduce incidence of hypertensive complications.

Confirmation that Plasmodium falciparum has aperiodic infectivity to Anopheles gambiae.

In preparation for field studies of transmission-blocking malaria vaccines, a study was carried out to determine whether P. falciparum infections obtained in An. gambiae blood-fed at 16.00 hours were quantitatively similar to infections obtained at 23.00 hours. Using a group of children aged 5-12 years from villages at Ahero, near Kisumu in Kenya, 71/74 (96%) of whom were found to be positive for P.falciparum parasitaemia, one batch of fifty colony-bred An.gambiae females were fed on volunteers at 16.00 hours and another batch at 23.00 hours. No statistically significant differences were found in the proportions of mosquitoes becoming infected, the numbers of children infecting mosquitoes or the mean numbers of malaria oocysts developing in mosquitoes blood-fed at the different times. Because mosquito infections obtained by day (16.00 hours) are equivalent in quantity to those obtained at night (23.00 hours), experimental infections can be carried out in the afternoon, when it is most convenient, rather than during the night.

Mitogenic activities in African traditional herbal medicines.

Mitogenic activities in African traditional herbal medicines were examined using protein fractions obtained from their extracts by precipitation with ammonium sulfate. Potent mitogenic activities for human and mouse lymphocytes were found in the three plants: Croton macrostachyus, Croton megalocarpus (Euphorbiaceae), and Phytolacca dodecandra (Phytolaccaceae). All the gel chromatographic patterns of these protein fractions progressed toward the smaller molecule site with pronase treatment, while their mitogenic activities decreased significantly. Protein fractions from these three plants induced mitogenesis both in human and mouse isolated T cells, but not in lymphocytes from athymic nude mice. By testing further fractionated protein fractions with gel filtration chromatography, it was found that all three plants contained several mitogens having different molecule sizes.

Plasmodium falciparum sporozoite and entomological inoculation rates at the Ahero rice irrigation scheme and the Miwani sugar-belt in western Kenya.

Anopheles arabiensis and An. funestus were collected by pyrethrum spray sheet collections in houses and by human-bait catches at a village in western Kenya adjacent to the Ahero rice irrigation scheme; and using the same methods, An. gambiae s.l. and An. funestus were collected at Miwani, a village in the sugar-cane belt. Plasmodium falciparum sporozoite rates were determined by ELISA. At Ahero the mean sporozoite rates were 1.1% and 4.3% in An. arabiensis and An. funestus, respectively, while at Miwani the rates were 6.0% in An. gambiae s.l. and 4.3% in An. funestus. Entomolgoical inoculation rates (EIR) were derived from both human-bait collections (IR-HBC) and by the proportion of human blood-fed females caught resting indoors (IR-HBF). The IR-HBF appeared to be a more realistic index of EIR. At Ahero and Miwani people were exposed to an average of 416 and 91 infective bites/person/year, respectively. The main vectors were An. funestus at Ahero and An. gambiae s.l. at Miwani. In view of the intense and perennial malaria transmission at Ahero, vector control by insecticides should be considered, while at Miwani, where transmission is seasonal, permethrin-impregnated bed nets could be an alternative to indoor spraying. These measures must be augmented with availability of effective antimalarials.

Acetylation status using hydralazine in African hypertensives at Kenyatta National Hospital.

In this study, the investigation of hydralazine acetylator phenotype was undertaken for the first time in African hypertensives at Kenyatta National Hospital. A total of 25 randomly selected patients with moderate to severe hypertension (diastolic pressure 105-130 mmHg), participated in the phenotyping study. The phenotyping was done by administering oral standard hydralazine dose of 150 mg/day in three divided doses. The 24 hour urinary MTP/hydralazine ratio was used to categorize patients into slow and fast acetylators. Of the patients studied 69.9% were slow acetylators while 30.4% were fast acetylators. The mean 24 hour urinary MTP/hydralazine ratio for slow acetylators was 1.01 +/- 0.95. This was significantly different from the fast acetylators where the mean 24 hour urinary MTP/hydralazine ratio was 10.6 +/- 4.4 (P < 0.001). The acetylator phenotyping divided the patients into two distinct populations and no further arbitrary method was required to divide the patients into either group.

A comparative study of the neutralising capacity of eight brands of antacids.

Eight brands of antacid tablets commonly available in the private market in Kenya were subjected to in-vitro tests for neutralizing capacity. The neutralizing capacity per gram and per tablet of the products was compared. The neutralizing capacity in millilitres of 0.1 M HC1 per gram ranged from 103.10 for Gelusil to 225.13 for Maalox, with others ranging between +/- 18.1% and -12% about the average. The neutralizing capacity per tablet ranged from 64.90 ml for Magnesium trisilicate Co tablets B.P. to 263.15 ml for Maalox, with the others ranging between +/- 24.9% and -33.1% about the average. This shows high variation in the neutralizing capacities of the different brands available especially in relations to the neutralizing capacities per tablet due to the high variation in the tablet weight.

Mefloquine disposition in normals and in patients with severe Plasmodium falciparum malaria.

Mefloquine pharmacokinetics were studied in Kenyan African normal volunteers and in patients with severe acute attack of Plasmodium falciparum malaria. Peak concentrations were achieved in both groups at 20-24 hours. The mean half-life of elimination was 385 +/- 150 hours (mean +/- SD) in normal subjects while in severe malaria it was 493 +/- 215 hours which was significantly longer (P less than or equal to 0.001). The volume of distribution was significantly smaller in severe malaria where it was 30.76 +/- 10.50 l/kg (mean +/- SD) while in the normal subjects it was 40.90 +/- 20.70 l/kg (mean +/- SD) (P less than or equal to 0.001). The total body clearance in severe malaria was 3.75 +/- 1.51 l/h (mean +/- SD). This was significantly lower than in the normal subjects where it was 5.15 +/- 1.50 l/h (mean +/- SD) (P less than or equal to 0.001).

Disposition of antipyrine in African patients with Hodgkin's lymphoma.

The pharmacokinetics of antipyrine were studied in 12 healthy volunteers and 10 patients of Kenya African origin with Hodgkin's lymphoma. The half-life of antipyrine was 12.2 +/- 1.3 h (mean + s.d.), while the apparent volume of distribution (V) was 0.67 +/- 0.11 l kg-1 (mean +/- s.d.) and the total body clearance was 40.7 +/- 3.2 ml kg-1 h-1 (mean +/- s.d.) in the healthy volunteers. The antipyrine half-life in the patients with advanced Hodgkin's lymphoma was 17.1 +/- 2.7 h (mean +/- s.d.). The apparent volume of distribution was 0.72 +/- 0.14 l kg-1 (mean +/- s.d.) which was larger than in healthy volunteers (P less than 0.05). The total body clearance was 30.3 +/- 9.4 ml kg-1 h-1 (mean + s.d.) and this was reduced compared with that in healthy volunteers (P less than 0.02). After cytotoxic therapy the half-life in the patients with advanced Hodgkin's lymphoma was significantly decreased to 8.3 +/- 1.3 h (mean +/- s.d.) (P less than 0.07), and the apparent volume of distribution was reduced to 0.65 +/- 0.07 l kg-1 (mean +/- s.d.) (P less than 0.05) while the total body clearance increased to 52.8 +/- 5.5 ml kg-1 h-1 (mean +/- s.d.) (P less than 0.01).