Mapping potential Anopheles gambiae s.l. larval distribution using remotely sensed climatic and environmental variables in Baringo, Kenya.

Anopheles gambiae s.l. (Diptera: Culicidae) is responsible for the transmission of the devastating Plasmodium falciparum (Haemosporida: Plasmodiidae) strain of malaria in Africa. This study investigated the relationship between climate and environmental conditions and An. gambiae s.l. larvae abundance and modelled the larval distribution of this species in Baringo County, Kenya. Mosquito larvae were collected using a 350-mL dipper and a pipette once per month from December 2015 to December 2016. A random forest algorithm was used to generate vegetation cover classes. A negative binomial regression was used to model the association between remotely sensed climate (rainfall and temperature) and environmental (vegetation cover, vegetation health, topographic wetness and slope) factors and An. gambiae s.l. for December 2015. Anopheles gambiae s.l. was significantly more frequent in the riverine zone (P < 0.05, r = 0.59) compared with the lowland zone. Rainfall (b = 6.22, P < 0.001), slope (b = - 4.81, P = 0.012) and vegetation health (b = - 5.60, P = 0.038) significantly influenced the distribution of An. gambiae s.l. larvae. High An. gambiae s.l. abundance was associated with cropland and wetland environments. Effective malaria control will require zone-specific interventions such as a focused dry season vector control strategy in the riverine zone.

MicroResearch: finding sustainable local health solutions in East Africa through small local research studies.

BACKGROUND: Sub-Saharan African countries have urged grassroots input to improve research capacity. In East Africa, MicroResearch is fostering local ability to find sustainable solutions for community health problems. At 5years, the following reports its progress. METHODS: The MicroResearch program had three integrated components: (1) 2-week training workshops; (2) small proposal development with international peer review followed by project funding, implementation, knowledge translation; (3) coaching from experienced researchers. Evaluation included standardized questions after completion of the workshops, 2013 online survey of recent workshop participants and discussions at two East Africa MicroResearch Forums in 2013. RESULTS: Between 2008 and 2013, 15 workshops were conducted at 5 East Africa sites with 391 participants. Of the 29 projects funded by MicroResearch, 7 have been completed; of which 6 led to changes in local health policy/practice. MicroResearch training stimulated 13 other funded research projects; of which 8 were external to MicroResearch. Over 90% of participants rated the workshops as excellent with 20% spontaneously noting that MicroResearch changed how they worked. The survey highlighted three local research needs: mentors, skills and funding - each addressed by MicroResearch. On-line MicroResearch and alumni networks, two knowledge translation partnerships and an East Africa Leaders Consortium arose from the MicroResearch Forums. CONCLUSION: MicroResearch helped build local capacity for community-directed interdisciplinary health research.

CD4 T-LYMPHOCYTE SUBSETS IN WOMEN WITH INVASIVE CERVICAL CANCER IN KENYA.

OBJECTIVE: Invasive cervical cancer (ICC) and HIV are common in sub-Sahara Africa. Both ICC and HIV are immunosuppressive, and are associated with decreased CD4 and CD8 profiles. In a group of women with ICC starting radiotherapy, we determined their CD4 profiles. DESIGN: A cross-sectional study. SETTINGS: Kenyatta National Hospital, Nairobi, Kenya, radiotherapy unit. SUBJECTS: Women with invasive cervical cancer (344) seeking radiotherapy treatment for the first time between January 2000 and March 2003, had blood samples analyzed for CD4 and CD8 cell counts by flow cytometry. Haemoglobin, white cell count, lymphocyte and platelet counts were determined using coulter machine. All patients had received pre- and post HIV counseling. RESULTS: The mean age was 49+13 years. About 13.1% of the women with ICC were HIV positive. Overall, mean and median CD4 cell count was 829+355 cells/mm and 792 cells/mm3. Among HIV+ patients, mean and median CD4 cell counts were 451+288 cells/mm and 405 cells/mm respectively. The mean CD4 cell count for the HIV+ womenwas 886+329 cells/mm3 with median of 833 cells/mm3, range 147-2065 cells/mm3. Only nine (20%) of the 45 HIV+ women had CD4 cell count of 0-200. HIV+ women had lower CD4 percentage and cell count and higher CD8 percentage and cell count as compared to HIV negative women, p < 0.001. HIV infection was significantly and independently associated with high proportion of women who had CD4 cell count of less than 200 cells/mm3 or less than 350 cells/mm3, p < 0.0001. CONCLUSIONS: Women with ICC and concurrent HIV infection have decreased CD4 cell subset. These results suggest HIV infection may be associated with more severe CD4 depletion in women with ICC.

Intermittent presumptive treatment of malaria to prevent low birth weight in newborns in a cohort of pregnant women from a malaria endemic area.

OBJECTIVE: To determine and describe the patterns of low birth weight in newborns of a cohort of mothers given intermittent presumptive treatment (IPT) for malaria prevention in a malaria endemic area of Kenya. DESIGN: A longitudinal prospective cohort study. SETTING: Got Agulu Health Centre in Usigu Division, Bondo District, Nyanza Province. SUBJECTS: Pregnant women of all parities attending antenatal care services. Only women who gave informed consent for themselves and their newborns after birth were eligible to participate in the study. RESULTS: Parity was highly predictive of birth weight in the study subjects. Primigravidae and secondigravidae had a significantly lower mean birth weight (2952g) than women of higher gravidity (3214g) p-value <0.0001. Regardless of IPT administration, women who became positive for malaria infection at any point during pregnancy delivered 73.7% of the LBW infants. There was no significant difference in mean birth weights between primigravidae and multigravidae who had parasitaemia at baseline and at delivery (means 2906g and 3062g respectively, p=0.11). However, there was a significant difference between the parasitaemia negative primigravidae and multigravidae at baseline and at delivery (means 2952g and 3204g respectively, p=0.006). Infection with helminths did not have an effect on birth weight. Overall, low birth weight was observed in 9% of the newborns and was most commonly found in primigravidae and secondigravidae (14.8% and 13.1% respectively). CONCLUSION: Although many factors have been known to play a role in the causation of low birth weight (LBW <2500g), parity status and malaria infection in malaria endemic areas still play a major role regardless of IPT administration.

Predictors of serum ferritin and haemoglobin during pregnancy, in a malaria-endemic area of western Kenya.

Between 2000 and 2004, a cross-sectional survey was conducted, as part of a prospective cohort study, among the women attending antenatal-care clinics in Bondo district, a malaria-endemic area of western Kenya. The aim was to assess the prevalence of iron deficiency and determine the predictors of haemoglobin and serum ferritin concentrations in the women who had a gestational age between 14 and 24 weeks. A standardized questionnaire was used to collect and store the relevant bio-data for the study. Haemoglobin and ferritin concentrations were evaluated, sickle-cell status was determined, and malarial parasitaemias were detected and evaluated, using blood samples collected at enrollment. Multiple regression analysis was then used to test for significant predictors of the haemoglobin and serum ferritin concentrations. Although 842 women were enrolled in the prospective cohort study, haemoglobin concentrations were evaluated for only 828 of them, serum ferritin levels for 621, and levels of parasitaemia for 812. The mean haemoglobin concentration recorded was 10.9 g/dl. Although 37.9% of the subjects had mild-moderate anaemia (7.0-10.5 g haemoglobin/dl), only 0.5% were severely anaemic (<7.0 g haemoglobin/dl). The geometric mean serum ferritin concentration recorded was 18.9 microg/litre, and 32.3% of the subjects evaluated had low serum concentrations of ferritin (<12 microg/litre). Among the parasitaemic primigravidae (but not the parasitaemic multigravidae), those found positive for sickle-cell trait had significantly lower haemoglobin concentrations than those found negative in a sickling test (P=0.01). Among the pregnant women of Bondo district, gravidity, malarial infection and sickle cell appear to be key predictors of haemoglobin concentration.

Mineral content of traditional leafy vegetables from western Kenya.

Socio-economic changes that have taken place in Africa have influenced people's eating habits in both rural and urban set-ups. Most people prefer introduced foods to traditional foods, including plant foods whose consumption is widely regarded as a primitive culture manifesting poor lifestyles. However, recent studies on traditional plant foods have shown that some are highly nutritious; containing high levels of both vitamins and minerals. They also have potential as a remedy to counter food insecurity since most are well adapted to the local environment, enabling them to resist pests, drought and diseases. This paper describes the mineral (calcium, iron and zinc) contents in some 54 traditional vegetable species collected from Nyang'oma area of Bondo district, western Kenya. Atomic absorption spectroscopy was used to determine the mineral content. We found that most traditional leafy vegetables, domesticated and wild, generally contain higher levels of calcium, iron and zinc compared with the introduced varieties such as spinach (Spanacia oleracea), kale (Brassica oleracea var. acephala) and cabbage (Brassica oleracea var. capitata). The results of this study could contribute towards identification, propagation and subsequent domestication and cultivation promotion of nutrient-rich and safe species within the farming systems of the local communities in Kenya, sub-Saharan Africa or elsewhere.

Acceptability of human immunodeficiency virus testing in patients with invasive cervical cancer in Kenya.

Invasive cervical cancer (ICC) is common in areas where human immunodeficiency virus (HIV) is also prevalent. Currently, HIV seroprevalence as well as acceptability of HIV testing in ICC patients in Kenya is unknown. The objective of this study was to determine the acceptability of HIV testing among patients with ICC. Women with histologically verified ICC at Kenyatta National Hospital participated in the study. A structured questionnaire was administered to patients who gave informed consent. HIV pre- and posttesting counseling was done. Blood was tested for HIV using enzyme-linked immunosorbent assay. Overall, 11% of ICC patients were HIV seropositive. The acceptance rate of HIV testing was 99%; yet, 5% of the patients did not want to know their HIV results. Patients less than 35 years old were two times more likely to refuse the result of the HIV test (odds ratio [OR] 2.2). Patients who did not want to know their HIV results were three times more likely to be HIV seropositive (OR 3.1). Eighty four percent of the patients were unaware of their HIV seropositive status. The HIV-1 seroprevalence in ICC patients was comparable to the overall seroprevalence in Kenya. ICC patients were interested in HIV testing following pretest counseling. Offering routine HIV testing is recommended in ICC patients.

Bancroftian filariasis in 12 villages in Kwale district, Coast province, Kenya - variation in clinical and parasitological patterns.

As part of a larger study on the effects of permethrin-impregnated bednets on the transmission of Wuchereria bancrofti, subjects from 12 villages in the Coastal province of Kenya, south of Mombasa, were investigated. The aims were to update the epidemiological data and elucidate the spatial distribution of W. bancrofti infection. Samples of night blood from all the villagers aged i 1 year were checked for the parasite, and all the adult villagers (aged >/= 15 years) were clinically examined for elephantiasis and, if male, for hydrocele. Overall, 16.0% of the 6531 villagers checked for microfilariae (mff) were found microfilaraemic, although the prevalence of microfilaraemia in each village varied from 8.1%-27.4%. The geometric mean intensity of infection among the microfilaraemic was 322 mff/ml blood. At village level, intensity of the microfilaraemia was positively correlated with prevalence, indicating that transmission has a major influence on the prevalence of microfilaraemia. Clinical examination of 2481 adults revealed that 2.9% had elephantiasis of the leg and that 19.9% of the adult men (10.8%-30.1% of the men investigated in each village) had hydrocele. Although the overall prevalence of microfilaraemia in the study villages had not changed much since earlier studies in the 1970s, both prevalence and intensity varied distinctly between the study villages. Such geographical variation over relatively short distances appears to be a common but seldom demonstrated feature in the epidemiology of bancroftian filariasis, and the focal nature of the geographical distribution should be carefully considered by those mapping the disease.

Knowledge and practice about cervical cancer and Pap smear testing among patients at Kenyatta National Hospital, Nairobi, Kenya.

Invasive cervical cancer (ICC) is the leading cause of cancer-related death among women in developing countries. Population-based cytologic screening and early treatment does reduce morbidity and mortality associated with cervical cancer. Some of the factors related to the success of such a program include awareness about cervical cancer and its screening. The objective of this study was to assess knowledge and practice about cervical cancer and Pap smear testing among cervical cancer and noncancer patients using a structured questionnaire to obtain information. Fifty-one percent of the respondents were aware of cervical cancer while 32% knew about Pap smear testing. There were no significant differences in knowledge between cervical cancer and noncancer patients. Health care providers were the principal source of information about Pap testing (82%). Only 22% of all patients had had a Pap smear test in the past. Patients aware of cervical cancer were more likely to have had a Pap smear test in the past. The level of knowledge is low among ICC and noncancer patients. There is need to increase the level of knowledge and awareness about ICC and screening among Kenyan women to increase uptake of the currently available hospital screening facilities.

HIV and cervical cancer in Kenya.

OBJECTIVES: To determine the effect of the HIV epidemic on invasive cervical cancer in Kenya. METHODS: Of the 3902 women who were diagnosed with reproductive tract malignancies at Kenyatta National Hospital (KNH) from 1989 to 1998, 85% had invasive cervical cancer. Age at presentation and severity of cervical cancer were studied for a 9-year period when national HIV prevalence went from 5% to 5-10%, to 10-15%. RESULTS: There was no significant change in either age at presentation or severity of cervical cancer. Of the 118 (5%) women who were tested for HIV, 36 (31%) were seropositive. These women were 5 years younger at presentation than HIV-negative women. CONCLUSIONS: A two- to three-fold increase in HIV prevalence in Kenya did not seem to have a proportional effect on the incidence of cervical cancer. Yet, HIV-positive women who presented with cervical cancer were significantly younger than HIV-negative women.

Validity of the vaginal discharge algorithm among pregnant and non-pregnant women in Nairobi, Kenya.

OBJECTIVE: To evaluate the validity of different algorithms for the diagnosis of gonococcal and chlamydial infections among pregnant and non-pregnant women consulting health services for vaginal discharge in Nairobi, Kenya. METHODS: Cross sectional study among 621 women with complaints of vaginal discharge in three city council clinics between April and August 1997. Women were interviewed and examined for symptoms and signs of sexually transmitted infections (STIs). Specimens were obtained for laboratory diagnosis of genital infections, HIV, and syphilis. The data were used to evaluate the Kenyan flow chart as well as several other generated algorithms. RESULTS: The mean age was 24 years and 334 (54%) were pregnant. The overall prevalence rates were: 50% candidiasis, 23% trichomoniasis, 9% bacterial vaginosis, 7% gonorrhoea, 9% chlamydia, 7% syphilis, and 22% HIV. In non-pregnant women, gonococcal and chlamydial infection was significantly associated with (1) demographic and behavioural risk markers such as being single, younger than 20 years, multiple sex partners in the previous 3 months; (2) symptom fever; and (3) signs including presence of yellow or bloody vaginal discharge, cervical mucopus, cervical erythema, and friability. Among pregnant women only young age, dysuria, and fever were significantly associated with cervical infection. However, none of these variables was either sensitive or specific enough for the diagnosis of cervical infection. Several algorithms were generated and applied to the study data. The algorithm including risk markers performed slightly better than the current Kenyan algorithm. CONCLUSION: STIs form a major problem in the Nairobi area and should be addressed accordingly. None of the tested algorithms for the treatment of vaginal discharge would constitute a marked improvement of the existing flow chart. Hence, better detection tools for the specific aetiology of vaginal discharge are urgently needed.

Bacterial meningitis in children admitted in hospitals within Nairobi.

Four hundred and ninety nine children (aged between one month and five years) admitted with clinical features of meningitis were recruited in cross-sectional survey of bacterial meningitis in hospitals within Nairobi. Lumbar punctures were done on all of them and the cerebrospinal fluid (CSF) analysed bacteriologically and serologically for the common causative organisms. Two hundred and fifty (50.1%) cases were diagnosed clinically as having meningitis. Of these, 132 (52.8%) had turbid CSF specimens, while 118 (47.2%) were clear. When turbid CSF specimens were cultured, 83 (62.8%) yielded three common bacterial micro-organisms namely; Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae in that order of frequency. The implications of these findings in paediatric meningitis together with the drug sensitivity patterns is presented and discussed.

Bancroftian filariasis in Kwale District of Kenya. III. Quantification of the IgE response in selected individuals from an endemic community.

One hundred and sixty-two individuals from a community in Kwale District, Kenya, endemic for bancroftian filariasis, were selected for a study on the IgE response to filarial antigen (prepared from adult Brugia pahangi). Following clinical and parasitological examination, the individuals were grouped into different categories, based on the presence/absence of microfilaraemia, the presence/absence of acute or chronic (hydrocele or elephantiasis) clinical manifestations, and age. The total and filarial-specific IgE responses were evaluated in all individuals, and the responses in the various categories were compared with each other and with the responses of control groups of individuals from filariasis-free areas. The majority of individuals from the endemic area had highly elevated serum concentrations of total IgE. Overall and within each clinical category, the concentration of total IgE was higher in those individuals from the endemic area who had microfilaraemias than in those that did not. The majority of individuals from the filariasis endemic area also had significantly elevated levels of filarial-specific IgE. In contrast, the concentration of specific IgE was lower in subjects with microfilariae than in those without, irrespective of their clinical status. Only a small proportion of total IgE was filarial-specific, the mean value varying from 0.4% to 9.8%, depending on category. Among the endemic individuals, the mean proportion of total IgE which was filarial-specific was 3.6 times higher in the microfilaria-negative than in the microfilaria-positive, indicating that much of the filarial-induced IgE in microfilaraemic individuals could be non-specific. No clear relationship was observed between the IgE response and the clinical manifestations or age of the endemic individuals.(ABSTRACT TRUNCATED AT 250 WORDS)

Typhim Vi vaccine against typhoid fever: a clinical trial in Kenya.

Safety, tolerance and immunogenicity of the purified Vi polysaccharide vaccine (Typhim Vi) against typhoid fever was evaluated in primary school children aged 5-15 years. A total of 435 children were vaccinated, each with a single intramuscular injection in the left deltoid muscle. One hundred and ten children were randomly selected for blood samples on day 0 (pre vaccination) and day 30 (post vaccination). Vi antibodies studied by Radio immuno assay (RIA) on 97(88%) paired sera showed a seroconversion rate of 76.2% and seroprotection rate after vaccination was 74.2%, while 6.2% of children already had protective immunity before vaccination. The vaccine was well tolerated. Most commonly reported reactions were mild pain at site of injection (83%), and a few complained of mild swelling (4.6%), induration (1.1%), itching (1.1%) and headaches (1.4%). All reactions were of mild severity and disappeared within 24 to 48 hours.

Bancroftian filariasis in Kwale District of Kenya. I. Clinical and parasitological survey in an endemic community.

A cross-sectional parasitological and clinical survey for Wuchereria bancrofti infection was carried out in an endemic community of south-eastern Kenya, to obtain background epidemiological information for detailed serological studies on bancroftian filariasis in the same community. Quantitative examination of night blood samples (100 microliters) from 1129 individuals (76% of the population), using the counting chamber technique, revealed circulating microfilariae in 13.7% of the study group. Prevalence increased with age, and was higher in males (15.9%) than in females (11.6%). The geometric mean intensity among infected individuals was 223 microfilariae/ml blood (336 microfilariae/ml for males and 212 microfilariae/ml for females). Approximately 16.5% of the males aged > or = 15 years had hydrocele and 2.4% of the population had elephantiasis. The prevalence of these conditions increased with age; in those aged > or = 50 years, 23.8% of males had hydrocele and 6.1% of the total population had elephantiasis. Acute cases of epididymo-orchitis, adenolymphangitis and funiculitis were also seen. The microfilarial prevalence in males with hydrocele was not significantly different from that in asymptomatic males, but none of the elephantiasis cases had microfilaraemia. The striking difference in microfilaraemia pattern between hydrocele and elephantiasis patients may reflect different mechanisms underlying the development of these two chronic manifestations. The overall prevalences of microfilaraemia and clinical manifestations in this community were moderate when compared with those found in other studies carried out along the coast of eastern Africa.

Bancroftian filariasis in Kwale District of Kenya. II. Humoral immune responses to filarial antigens in selected individuals from an endemic community.

Humoral immune responses to filarial infection were investigated in 162 individuals, covering the full clinical and parasitological spectrum of bancroftian filariasis as seen in an endemic community of Kwale District, Kenya. Sera were tested for specific antifilarial antibodies (total immunoglobulins, IgM, IgGl, IgG4 and IgE) using ELISA. Most individuals showed an immunological response to the filarial antigen (prepared from adult Brugia pahangi). How these responses were related to the clinical manifestations, parasitological status and age was analysed by comparing the mean antibody levels among different categories of endemic individuals, and by comparing these to the levels in control groups from filariasis-free areas. IgM and IgE anti-filarial antibodies were detected with low specificity in unabsorbed sera. A higher specificity, clearly distinguishing the mean antibody levels in the endemic categories from those of control groups, was obtained for total specific immunoglobulins, and for IgE in sera absorbed with protein A. The most specific results were obtained for IgGl and IgG4; clear inter-category differences were observed for these classes. The mean level of specific IgG4 was significantly higher in microfilaraemic groups than in amicrofilaraemic groups, whereas the mean level of specific IgGl was significantly higher in amicrofilaraemic, symptomatic cases than in microfilaraemic, symptomatic cases. In most categories of endemic individuals, and for most antibody isotypes, the mean levels of specific antibodies tended to be higher (although not significantly) in the younger individuals than in the older individuals. Overall, the differences in the filarial antibody responses were more closely related to the presence or absence of microfilariae and to the age of the individuals than to the disease manifestations in this endemic population.

Protozoan infections and HIV-1 infection: a review.

Reactivation of latent infection is the principal mechanism relating Toxoplasma gondii and Pneumocystis carinii to HIV. Less common is reactivation in Leishmania donovani, Trypanosoma cruzi, and microsporidian infections. An impaired primary immune response occurs in all these infections, and also with Cryptosporidium and Isospora belli. Association of HIV infection with gut parasites including Giardia lamblia and Entamoeba histolytica, and also with Trichomonas vaginalis infection is likely to be related to sexual modes of contact that favour both HIV and the parasite. The severity of malaria is not definitely associated with HIV, but Plasmodium falciparum infection may favour more rapid evolution of the HIV infection. Both malaria and trichomoniasis favour HIV transmission; the former by necessitating blood transfusion, and the latter by enhancing viral transmission during sexual contact.