Improved diagnosis of Ziehl-Neelsen smear negative tuberculosis using sodium hypochlorite sedimentation method.

BACKGROUND: Bacteriological diagnosis of tuberculosis (TB) is largely dependent on Ziehl-Neelsen (ZN) microscopy. This method has a low sensitivity. Although concentration of sputum with sodium hypochlorite (NaOC1) followed by sedimentation increases the sensitivity of direct smear microscopy, no study has focused on the effect of NaOC1 on smear negative sputum specimens. OBJECTIVE: To establish whether 3.5% NaOC1 sedimentation method specifically improves the diagnosis of Ziehl-Neelsen smear negative tuberculosis. DESIGN: A prospective study. SETTING: Mbagathi District Hospital and Center for Respiratory Diseases Research, Kenya Medical Research Institute. SUBJECTS: Two hundred and thirty confirmed direct ZN smear negative sputum specimens from new TB suspects were analysed. RESULTS: Seventy (30.4%) specimens were culture positive. Of these, 19 were ZN smear positive. The ZN sensitivity, specificity, positive and negative predictive values were 27.1%, 99%, 95% and 76%, respectively, after sedimentation with 3.5% NaOC1. CONCLUSION: Overnight sedimentation using 3.5% NaOC1 significantly improves diagnosis of ZN smear negative TB. This technique has potential to improve diagnosis in TB diagnostic services especially in settings with high burden of dual TB/HIV infection.

Combination of bleach and flourescent microscopy: a milestone in the diagnosis of smear negative tuberculosis.

BACKGROUND: The reliability of direct smear microscopy for diagnosis of tuberculosis has frequently been questioned due to low sensitivity. Treatment of sputum with sodium hypochlorite (NaOCI) has been used to increase sensitivity in many settings. However, no study has established the effect of NaOCI on fluorescent microscopy. OBJECTIVE: To establish whether NaOCI concentration method enhances positivity of fluorescent microscopy smear negative sputum for diagnosis of tuberculosis. DESIGN: A prospective study. SETTING: Mbagathi District Hospital and Centre for Respiratory Diseases Research, Kenya Medical Research Institute. RESULTS: Forty five (22%) specimens were culture positive. Fluorescent microscopy sensitivity was 28.9% and 22.2% after centrifugation and sedimentation with 3.5% NaOCI, respectively (P > 0.05). Sensitivity was 24.4% and 17.8% after centrifugation and sedimentation with 5% NaOCI, respectively (P > 0.05). Although there was no statistical significance difference between the two NaOCI concentration methods, 3.5% NaOCI with centrifugation indicated a higher yield. CONCLUSION: Use of NaOCI significantly enhances positivity of smear negative sputum for diagnosis of tuberculosis when used with fluorescent microscopy. This approach could be recommended for screening all tuberculosis suspects especially in settings with potential smear negative tuberculosis.

Epidemiology of HIV infection among long distance truck drivers in Kenya.

A total number of two hundred eighty three long distance truck drivers and their assistants (loaders) who ferry goods between Kenya and Zaire were included in a cross-sectional study between September 1991 and April 1992. Twenty six percent of the study subjects were seropositive for HIV-1 and none were HIV-2 seropositive. Countries of birth and residence were significantly associated with HIV infection (X2 = 23.6, P = 0.0006). Significant associations were also found between HIV seropositivity and level of education from secondary school and above (OR = 3.4, 95% C.I. = 1.01-11.55); being circumcised was more protective, (OR = 0.38; 95% C.I. = 0.19-0.76), history of many years of driving (X2 = 9.3, p = 0.0254) and income (OR = 11.13, 95% C.I. = 1.35-91.95). When a stepwise multiple logistic regression model was fitted to all the variables observed to be significant in the univariate analysis, the following risk factors attained statistical significance: lack of circumcision (OR = 3.75); income greater than Ksh. 2000 (OR = 7.24); being employed in long distance driving more than 11 years (OR = 3.98); and secondary school education and above (OR = 4.06, 95% C.I. = 1.18-13.98). Reference for all the above Odds Ratios was 1.

PIP: A total number of 283 long distance truck drivers and their assistants (loaders) who ferry goods between Kenya and Zaire were included in a cross-sectional study between September 1991 and April 1992. 26% of the study subjects were seropositive for HIV-1 and none were HIV-2 seropositive. Countries of birth and residence were significantly associated with HIV infection (chi square = 23.6, p = 0.0006). Significant associations were also found between HIV seropositivity and level of secondary school education and above (OR = 3.4, 95% CI = 1.01-11.55); being circumcised, which was more protective (OR = 0.38, 95% CI = 0.19-0.76); a history of many years of driving (chi square = 9.3, p = 0.0254); and income (OR = 11.13, 95% CI = 1.35-91.95). When a stepwise multiple logistic regression model was fitted to all the variables observed to be significant in the univariate analysis, the following risk factors attained statistical significance: lack of circumcision (OR = 3.75); income greater than Ksh. 2000 (OR = 7.24); being employed in long distance driving more than 11 years (OR = 3.98); and secondary school education and above (OR = 4.06, 95% CI = 1.18-13.98). Reference for all the above odds ratios was 1.

Pattern of Schistosoma mansoni infection after intervention in Mwea irrigation scheme in Kenya.

A longitudinal study of Schistosoma mansoni reinfection rate was carried out in an endemic area of Kenya, after intervention. Intervention measures applied involved chemotherapy, community mobilization to effect change in water contact habits and faecal disposal. This paper focuses on S. mansoni reinfection pattern over a two-year period. The age group 5-19 years showed an increasing trend of reinfection as compared to the 30-59 years age group. More than 50% in the 5-19 year age group had been reinfected by twelve months of follow-up. They were also responsible of 91% of all the egg-load and 83% of all the infections at the end of the study period. Since majority of the 5-19 year age group comprises school children, there is an urgent need of including issues related to schistosomiasis in the school curriculum especially in the endemic areas.

PIP: Schistosomiasis is a parasitic disease caused by blood flukes which live in the mesenteric and/or vesical veins of humans over a life span of several years. Cercariae are released by infected intermediate snail hosts into fresh water whose larvae then penetrate the skin of man when the individual contacts infected fresh water. Schistosomiasis is debilitating, setting in slowly and causing concern in its chronic stages. Chronic infection results in complications such as liver fibrosis and portal hypertension for Schistosoma mansoni and ureteric obstruction, bacterial infection, and cancer of the bladder for S. haematobium. In endemic areas, children have the highest prevalence and intensity of infection due to their more extensive contact with water relative to adults. Chemotherapy helps to control the disease, but population immigration, untreated pregnant women and very young children, and the selectiveness of control strategies make reinfection inevitable. This paper reports findings on the rate of reinfection with S. mansoni in Kirinyaga district, Kenya, between September 1983 and December 1988, after a prevention and control intervention. Schistosomiasis is endemic in that area of Kenya. Measures applied during the intervention included chemotherapy and community mobilization to effect change in water contact habits and faecal disposal. Individuals aged 5-19 years showed an increasing trend of reinfection compared to individuals aged 30-59 years, with more than 50% of subjects in the 5-19 year old age group being reinfected by twelve months of follow-up. The young age group also accounted for 91% of the egg-load and 83% of all infections at the end of the study period. The majority of the 5-19 year old age group comprises school children. An urgent need therefore exists to cover schistosomiasis-related issues in schools.

Clinical and immunological markers in Kenyan pulmonary tuberculosis patients with and without HIV-1.

Amongst newly diagnosed pulmonary tuberculosis patients, 44% were co-infected with human immunodeficiency virus (HIV). Pulmonary tuberculosis patients with HIV-1 presented more frequently with lymphadenopathy and diarrhoea than those without HIV-1. Peripheral blood CD4+ counts were significantly lower in patients with pulmonary tuberculosis with HIV-1 than those with pulmonary tuberculosis alone, P = 0.0292. CD4+ lymphocyte counts, lymphadenopathy and BCG scar could serve as indicators of HIV-1 infection in pulmonary tuberculosis (PTB) patients.

PIP: 87 newly diagnosed pulmonary tuberculosis (PTB) patients at the Infectious Diseases Hospital, Nairobi, Kenya, were recruited into the study. Only patients with acid fast bacilli on stained smears of expectorated sputum were considered to have PTB. Cases were presumed PTB when a negative sputum smear was obtained in a patient with clinical and radiographic features consistent with PTB. Heparinized peripheral venous blood from each patient was tested for antibodies to HIV-1 with the Dupont HTLV 111 and the Wellcozyme Diagnostics ELISA. Only samples seropositive with both ELISAs were considered HIV-1 seropositive. T-lymphocyte subpopulation was separated from mononuclear cells by centrifugation on a Ficoll-Hypaque gradient. There were approximately equal numbers of males and females (25 males and 24 females) in the HIV-1 negative group but as many as 26 males compared to 12 females in the HIV-1 positive group. The sex ratio in the HIV-1 negative was M/F; 1:0.96 and M/F; 1:0.5 in the HIV-1 positive group. The mean age of patients with HIV-1 (33.4 +or- 7.22) was significantly higher than those without HIV-1 (28.70 +or- 11.20; p0.001). The overall prevalence of HIV-1 was 44%; higher in men (30%) than in women (14%). The hemoglobin (12.0 +or- 2.6 gm HIV-1 negative; 12.0 +or- 1.4.0 gm HIV-1 positive) and total lymphocyte counts (2451.6 +or- 1036.7/cubic mm HIV-1 negative; 2020.9 +or- 1258.6/cubic mm HIV-1 positive) were not significantly different between the 2 groups. However, the white blood cell count was significantly higher in HIV-1 seronegative group (7273.5 +or- 4700/cubic mm) than in the HIV-1 seropositive group (5094.8 +or- 3494/cubic mm); p0.05). Patients with HIV-1 presented more often with lymphadenopathy, diarrhea and weight loss, whereas cough and fever were as common in HIV-1 positive as HIV-1 negative patients. Even though CD3, CD4, and CD8 counts were significantly lower in HIV-1 positive patients, the ratio of CD4/CD8 was not significantly different between the 2 groups.

Perception of a schistosomiasis control project in rural Kenya by the beneficiaries.

A schistosomiasis control project was implemented in Mwea Rice Irrigation Scheme in Central Kenya between late 1983 and December 1988 by Kenya Medical Research Institute scientists in collaboration with the National Irrigation Board. The aim of the project was to control schistosomiasis through provision of alternative water sources, bath and laundry units, latrines, chemotherapy and health education. The community participated fully. Five years later in December 1988, 203 household heads were interviewed on their perception of the control project in terms of purpose, project ownership and management, benefits, continuity and their knowledge of schistosomiasis transmission cycle. 61% of the respondents were females and 39% males. 92% of them said that the purpose for the project was to treat, control and prevent bilharzia from spreading, and to promote good health. Slightly over 50% said that the project belonged to them but that they would have liked to be more involved in its management. 74% said that they are able to save time because the facilities are now nearer to them; whilst 79% felt that they were saving money because they did not have to buy drugs since they felt healthier. 99% said that they thought that bilharzia has been controlled, and 82% said that their children looked healthier. 95% said that they could see the project surviving for a long time period suggesting that it was self sustaining and they were willing to start a maintenance of facilities fund. Overall, the community appreciated the social, economic and health benefits derived from the control project.

PIP: In December, 1988, a medical student and field workers interviewed 203 household heads (61% females and 39% males) in Thiba, a village in the Mwea Rice Irrigation Scheme in Kirinyaga District in central Kenya, as part of an evaluation of the schistosomiasis (bilharzia) control project implemented between late 1983 and December, 1988. Specifically, researchers wanted to know the perceptions of the people that the project served. The project consisted of health education and a water and health committee, which managed the construction of pit latrines, handpump shallow wells, and laundry and bath units. Most everyone (92% and 96%) understood that the project aimed to treat, control, and prevent bilharzia from spreading and to reduce bilharzia morbidity, respectively. Only 53% thought that the project belonged to the community. The remaining heads believed the project belonged to the Kenya Medical Research Institute, Ministry of Health, or a combination of the community, supervisor, and field workers. 74% reported that they saved time because the facilities were nearby. 80% believed that they were saving money because they did not need to buy drugs, since they felt healthier than they did before project implementation. 82% thought that their children appeared healthier, mainly due to the provision of potable water and bathrooms near the well sites. Almost everyone (99%) believed that the control project controlled schistosomiasis. 70% considered their workload to be easier because of the reduced distances to water sources and easy-to-operate pumps that their children could use. More than 90% thought that the project could survive in the long term, if the entire community were trained to maintain the facilities and provided spare parts. This suggested that the project was self sustaining. More than 90% knew the cause of bilharzia, how it is transmitted, its treatment, and how to prevent and control it. In conclusion, the community recognized the socioeconomic and health benefits of the control project.

Involvement of a community in schistosomiasis control: a Kenyan experience.

This paper illustrates how community participation was achieved in a study that was carried out between 1983-1988 whose general objective was to reduce the transmission of schistosomiasis in a rice irrigation scheme in Kenya. A community of 2,219 people was mobilized through health education, to effect changes in behaviour regarding water contact, water use and faecal disposal. Health education, alternative water sources, latrines and mass chemotherapy with praziquantel were the schistosomiasis control strategies utilized in this study. By the end of 2 years, the canals were cleared of their thick vegetation, water, sanitation, bathing and washing facilities were constructed, water contact with infective waters was reduced, faecal contamination of water was reduced, the people's knowledge on schistosomiasis increased and the rate and intensity of schistosomiasis infection was reduced. The study demonstrated that it is possible to fully involve the community in disease control efforts.

Application of statistical methods in the papers published in the East African Medical Journal (EAMJ) since 1923.

The subject Statistics was hardly known in the research world at the time the EAMJ was being started in 1923. It was at this time, scientists working in their field of specialization were busy developing statistical methods with the aim of solving problems affecting them in their research work. Using a random sample of some of the papers published by the EAMJ, this paper evaluates the usage of statistical methods since 1923. Usage was very low before 1965, but started picking-up with a rising trend since then but still not impressive. Scientists should strive to apply statistical methods correctly in their research work. EAMJ should lay more emphasis on statistical refereeing as a policy to raise the quality of published papers in the Journal. If statisticians were not available, which often may be the case, scientists should be encouraged to show their work to other research colleagues working in similar areas, before sending the paper to the EAMJ. By adopting this approach, it is possible that the quality of papers will go up and the usage of statistical methods will increase.

Quality control in the laboratory diagnosis of tuberculosis.

The study was conducted in 4 hospital laboratories to assess the value of smear re-examination, duplicate smear and culture in quality control in the diagnosis of pulmonary tuberculosis. In each hospital 1 to 3 sputum specimens were collected from each suspect and examined by the Ziehl-Neelsen method. Smears along with corresponding specimens were sent to the reference laboratory for re-examination and examination of fresh duplicate smears and culture. A total of 994 specimens plus 23 known negative and 23 known positive controls were analysed. For each assessment method, both over-diagnosis and underdiagnosis were indicated with under-diagnosis being a more common problem in the four hospital laboratories. The limitations of these assessment methods are presented.

Social characteristics and sexual behaviour of women at high risk of HIV infection in a town in Central Province of Kenya.

Forty seven women food handlers who were considered to be at high risk of HIV infection in Thika town of Central Province of Kenya were studied. The women were interviewed individually for information related to their social characteristics and sexual behaviour. The study showed that 91% were bar attendants, 58% had less than 7 years of formal education and 95% were either unmarried or divorced. All the women had at least one child. One of them practised anal sex but the rest practised vaginal sex. Their opinions on condom use revealed that they lacked knowledge on the advantages of condom use. Certain issues have been raised by this study, which call for in depth studies or incorporation into ongoing studies.

PIP: Researchers from the Kenya Medical Research Centre in Nairobi, Kenya interviewed 250 women food handlers who attended a routine medical exam in Thika town in Central Province to learn social characteristics and sexual behavior of women at high risk of acquiring HIV in urban areas. They only included the 47 who charged for sex. 1 researcher spoke with them later in their local dialect. All but 2 were bar attendants. 96% of their clients were nationals and none reported foreigners. 85% were not originally from Thika town and 51% of these came from the neighboring district of Muranga. 51% of these high risk women had lived in Thika town from 1 monthw5 years. 36.2% had 6-7 years of schooling and only 1 had 12 years. 85% reported to not have reached the level of education they wanted to reach. 49% of these said they did not reach the desired level due to insufficient funds and 19% became pregnant and left school. Age of menarche corresponded with the age when the 47 women left school. 85% had 1-4 children. Moreover 43% had had at least 1 abortion. 53% had been divorced and 45% never had a husband. 60% reported having used at least 1 form of contraceptive. Yet none of these women had used condoms. Some of the reasons for not using them included not knowing the advantages of using condoms, no need to use then, and no sexual pleasure. Only 1 reported having both vaginal and anal sex. 36% had 2 partners/week. 66% said that they go to different parts of Kenya at least once a month. Most of these trips resulted in an overnight stay. 81% had been circumcised and 83% had pierced ears. These results demonstrated a strong need for AIDS and sexually transmitted disease prevention education for high risk women.

A comparative study of the efficacy of plaque control by a chewing stick and a tooth brush.

The purpose of this study was to compare the efficacy of a chewing stick and a tooth brush in plaque control. The study composed of two groups of 11 and 8 children aged 13 to 16 years who were randomly selected from a peri-urban school near Nairobi. Results showed that, except for the participants with moderate amounts of plaque, the net changes in the mean number of surfaces with a given plaque score were more when the participants were using a toothbrush than when they were using a chewing stick. For the group of participants who started using a chewing stick before they changed to the toothbrush, there were no significant net changes in the mean number of surfaces with a given plaque score except for those surfaces which had mild plaque deposits. It is concluded that for the patients with severe plaque deposits, the toothbrush is more efficacious than the chewing stick in plaque control. However, for those patients with moderate plaque deposits, the chewing stick is as efficacious as the toothbrush in plaque control.

Oral rehydration therapy and social marketing in rural Kenya.

In just a few years, oral rehydration therapy (ORT) has become the standard treatment to reduce infant diarrhoeal disease mortality in the developing world. The paper describes an ORT intervention campaign in a rural area in Western Kenya (Kakamega District). After about a year of careful preparation, the campaign was launched in January 1986 and compared the use of a value-added product (flavoured sachets) sold through private outlets in addition to primary care distribution of an unflavoured sachet in an experimental cell (Bukura Division). In a control cell (Novakholo Division), only unflavoured sachets were distributed free of charge through primary health care facilities. Using local perceptions of diarrhoeal disease management, the campaign in the experimental cell was carefully designed and mass communication techniques employed and adapted accordingly. Outcome assessments of the campaign, which lasted until March 1987, included the overall ORT utilisation over time. Changes in perceptions towards diarrhoeal disease management, direct assessments of mixing a 'safe and effective' solution accurately and other relevant process parameters were evaluated. Comparing several recent ORT intervention projects, the paper concludes that a combination of a commercial approach and mass communication techniques can further ORS use. If a proper incentive system for shopkeepers is installed and message design and ORS product are fully tailored to the perception and preferences of the target population, the commercial availability of ORS will create an extra demand of the product. However, this will not replace distribution of ORS salts delivered free of charge through primary care sources.