Assessment of indoor air quality at an electronic cigarette (Vaping) convention

E-cigarette (vaping) conventions are public events promoting electronic cigarettes, in which indoor use of e-cigarettes is allowed. The large concentration of people using e-cigarettes and poor air ventilation can result in indoor air pollution. In order to estimate this worst-case exposure to e-cigarettes, we evaluated indoor air quality in a vaping convention in Maryland (MD), USA. Real-time concentrations of particulate matter (PM₁₀) and real-time total volatile organic compounds (TVOCs), CO₂ and NO₂ concentrations were measured. Integrated samples of air nicotine and PM₁₀ concentrations were also collected. The number of attendees was estimated to range from 75 to 600 at any single observation time. The estimated 24-h time-weighted average (TWA) PM₁₀ was 1800 μg/m³, 12-fold higher than the EPA 24-h regulation (150 μg/m³). Median (range) indoor TVOCs concentration was 0.13 (0.04-0.3) ppm. PM₁₀ and TVOC concentrations were highly correlated with CO₂ concentrations, indicating the high number of people using e-cigarettes and poor indoor air quality. Air nicotine concentration was 125 μg/m³, equivalent to concentrations measured in bars and nightclubs. E-cigarette aerosol in a vaping convention that congregates many e-cigarette users is a major source of PM₁₀, air nicotine and VOCs, impairing indoor air quality. These findings also raise occupational concerns for e-cigarette vendors and other venue staff workers.

Prevalence of hepatitis B vaccination among health care workers in Nigeria in 2011-12

BACKGROUND

Hepatitis B virus (HBV) infection is an endemic infection in Nigeria. Health care workers (HCWs) are at risk of occupational exposures to HBV-infected blood and body fluids.

OBJECTIVE

To determine the prevalence and determinants of HBV vaccine coverage among HCWs in two teaching hospitals in Nigeria.

METHODS

This cross-sectional study was undertaken in 2011 and 2012 in two teaching hospitals in Jos, North-Central Nigeria, and Yenagoa, South-South Nigeria. A self-administered structured questionnaire was administered to HCWs to obtain socio-demographic data and history of HBV vaccination.

RESULTS

Out of 290 HCWs who participated in the study, 185 (64.5%) had received at least one dose of HBV vaccine; 105 (36.2%) had full coverage of three doses. Professional category and previous training in infection control were independently associated with HBV vaccination. House officers and laboratory scientists were more likely to be unvaccinated than resident doctors, consultant doctors and nurses. Full vaccine coverage was associated with younger age and shorter years of professional experience.

CONCLUSION

We observed a generally low rate of HBV vaccine coverage among HCWs in Nigeria. Establishment of policies on compulsory HBV vaccination of all HCWs in Nigeria is recommended.

Liver function test abnormalities in Nigerian patients with human immunodeficiency virus and hepatitis B virus co-infection

Data on baseline hepatic function of HIV and hepatitis B virus (HBV) co-infected patients are limited in sub-Saharan Africa. We assessed liver function test (LFT) abnormalities in Nigerian patients with HIV/HBV co-infection to highlight the impact of HIV on HBV-related liver disease in sub-Saharan Africa. A cross-sectional study involving 100 HIV/HBV co-infected patients and 100 age- and sex-matched HBV mono-infected controls. Blood testing for HIV antibodies, CD4+ cell count, hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), LFTs, platelet count, fasting blood glucose and lipid profile were carried out. Non-invasive hepatic fibrosis scores (aspartate aminotransferase-platelet ratio index [APRI] and FIB-4) were also calculated. Co-infected patients had deranged liver enzymes more than the controls (77% versus 64%, P = 0.04). The predominant patterns of enzyme derangement in co-infected patients were either predominantly ↑ALP (30% versus 4%, P < 0.0001) or mixed (30% versus 15%, P = 0.01) but predominantly ↑AST/ALT in the controls (25% versus 9%, P = 0.003). Co-infected patients had higher fibrosis scores for both APRI (P = 0.002) and FIB-4 (P = 0.0001). On further analysis, LFT abnormalities and fibrosis scores were only significantly higher in co-infected patients in the immune clearance and HBeAg-negative chronic hepatitis phases. LFT abnormalities are common in Nigerians with HBV infection and co-infection with HIV negatively impacts on hepatic function.

Rickets in Nigerian children: response to calcium supplementation

In a previous study of rachitic children in Jos, Nigeria we concluded that inadequate dietary intake of calcium was the primary contributing factor to the development of their rickets. The objective of the present study was to determine the effect of calcium supplementation in 10 children with radiographically and biochemically proven rickets from the same geographical area. Rachitic children were provided with calcium supplements of 1000 mg/day for a period of 3 months. Serum and urine samples were obtained at baseline and at 24 hours, 1 week, 4 weeks, and 12 weeks after initiation of supplementation. Serum calcium, phosphorus, alkaline phosphatase, intact parathyroid hormone, 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D were measured at each time point. Dietary recalls obtained at two separate times were used to estimate usual daily intakes of calcium and phosphorus. Ten non-rachitic age-matched controls from the same geographical area were recruited for comparison. Nine of 10 rachitic subjects had radiographic evidence of healing after 3 months of calcium therapy. Although serum calcium concentrations returned to control levels, other biochemical data indicated that the rickets of these subjects may have been multifactorial in aetiology, pointing to a possible defect in the synthesis of 25-hydroxyvitamin D.

Decreased polyunsaturated fatty acids in sickle cell anaemia

The purpose of this study was to determine if the growth retardation often associated with sickle cell anaemia could be related in part to a deficiency of essential fatty acids. We reported recently that children with sickle cell disease in Jos, Nigeria have lower levels of serum amino acids and higher levels of urinary amino acids than their healthy counterparts. In the current study, we determined that the serum phospholipids of children with sickle cell anaemia did not deviate in the proportions of the essential fatty acids, linoleic and alpha-linolenic they contain compared to controls. However, their serum phospholipid profiles were significantly different in the proportions of four other fatty acids. Specifically, the phospholipids of children with sickle cell anaemia contained 19 per cent more palmitic acid (P = 0.006), 22 per cent more oleic acid (P = 0.014), 18 per cent less arachidonic acid (P = 0.008), 51 per cent less eicosapentaenoic acid (P = 0.0008), and 43 per cent less decosahexaenoic acid (P = 0.001). These data show that children with sickle cell anaemia are not deficient in essential fatty acids, but that the fatty acid elongation and desaturation pathway is somehow disturbed in this disease.

Serum and urinary amino acid levels in sickle cell disease

Neonates with sickle cell disease (SCD) are of normal size at birth in terms of height and weight. However, by the sixth month of life their growth begins to lag significantly behind that of non-sicklers. We hypothesize that such growth retardation could be explained, at least in part, by the increased excretion of free amino acids in the urine of children with SCD. It is well established that in SCD there are abnormalities in the proximal tubules where amino acids are reabsorbed. We collected serum and urine samples from 13 patients with SCD (age range, 10 months to 14 years), and 17 age-and gender-matched controls, and analysed these specimens for free amino acids and creatinine. The SCD population was less well nourished than the controls, as evidenced by the lower serum prealbumin levels in the former group (91.3 v. 127 mg/l, P = 0.01). The serum concentrations of all of the essential amino acids were significantly reduced (21-47 per cent, P < 0.01) in the SCD subjects, as were those of most of the non-essential amino acids (exceptions: alanine, glutamic acid, proline). The urine concentrations of seven of the essential amino acids (indexed to creatinine) were increased in the SCD children. The greatest difference in urinary amino acid excretion was seen with methionine; the SCD subjects excreted 3.6-fold more methionine than the controls. These data indicate that reduced levels of serum amino acids resulting from increased urinary loss of these amino acids in children with SCD could contribute to the decreased growth rates one sees in children with this genetically inherited hematologic disorder.