Establishment and development of the National Tuberculosis Control Programme in Vietnam

OBJECTIVE

To describe the establishment and development of the National Tuberculosis Control Programme (NTP) of Vietnam.

METHODS

Data were obtained from the surveillance system established by the new NTP in 1986 and based on the principles now described as the WHO DOTS strategy.

RESULTS

The proportion of districts covered by the NTP increased from 40% in 1986 to almost 100% in 2000. The proportion of communes applying NTP guidelines increased from 18% in 1986 to 99.8% in 2000. The total number of tuberculosis cases notified increased from 8737 in 1986 to 89 792 in 2000. Most of these are new smear-positive cases. Based on WHO estimations of the incidence rate, the proportion of new smear-positive cases detected and put on short-course treatment has been over 70% since 1996. Reported cure rates with short-course chemotherapy are consistently over 85%.

CONCLUSIONS

DOTS is feasible in a low-income, high-burden country. The main reasons for success were political commitment, a well-functioning health network, integration of tuberculosis control into the general health service at district level, a continuous supply of drugs and effective external support. Major challenges are long-term financial support, expansion to remote areas and vulnerable groups, definition of the role of the private sector, and future developments of the HIV epidemic and multidrug resistance.

Co-factors related to the causal relationship between human papillomavirus and invasive cervical cancer in Honduras

BACKGROUND

A case-control study was conducted in Honduras to identify co-factors in the carcinogenic pathway by which human papillomavirus (HPV) causes invasive cervical cancer.

METHODS

Ninety-nine cases aged 23-65 (median 47) years participated. Two controls were matched to each case by age and clinic where they first presented for cytological screening; controls had no cervical abnormalities. Information on risk factors was obtained by personal interviews in the clinics regarding sociodemographic, reproductive and behavioral characteristics. Human papillomavirus was detected in cervical scrapes by general primer-mediated polymerase chain reaction (PCR) followed by sequence analysis to identify the different types present.

RESULTS

All cases had squamous cell tumours and most were FIGO (International Federation of Gynecologists and Obstetricians) class II or higher; HPV was strongly associated with cervical cancer (odds ratio [OR] = 7.66, 95% CI : 3.88-15.1). Among HPV-positive women, dose-response relationships were observed for education, age at first intercourse and exposure to wood smoke that persisted after adjustment for previous screening. Among HPV-negative women, the number of sexual partners and parity were associated with cervical cancer. The protective effect of previous cytological screening operated independently of HPV.

CONCLUSIONS

Our findings speak for the powerful role that both primary and secondary education plays in fostering a lifestyle that reduces the risk of invasive cervical cancer. The data suggest that important elements of such a lifestyle include later age at first sexual intercourse, a limited number of pregnancies, greater likelihood of undergoing cytological screening and reduced exposure to carcinogens in the household environment.

Where health care has no access: the nomadic populations of sub-Saharan Africa

Nomadic and seminomadic pastoralists make optimal use of scarce water and pasture in the arid regions south of the Sahara desert, spreading from Mauretania in the west to Somalia in East Africa. We attempted to summarize the fragmentary evidence from the literature on the health status of these populations and to assess the best ways to provide them with modern health care. Infant mortality is higher among nomadic than among neighbouring settled populations, but childhood malnutrition is less frequent. Nomads often avoid exposure to infectious agents by moving away from epidemics such as measles. Trachoma is highly prevalent due to flies attracted by cattle. The high prevalence of tuberculosis is ascribed to the presence of cattle, crowded sleeping quarters and lack of health care; treatment compliance is generally poor. Guinea worm disease is common due to unsafe water sources. Helminth infections are relatively rare as people leave their waste behind when they move. Malaria is usually epidemic, leading to high mortality. Sexually transmitted diseases spread easily due to lack of treatment. Leishmaniasis and onchocerciasis are encountered; brucellosis occurs but most often goes undetected. Drought forces nomads to concentrate near water sources or even into relief camps, with often disastrous consequences for their health. Existing health care systems are in the hands of settled populations and rarely have access to nomads due to cultural, political and economic obstacles. A primary health care system based on nomadic community health workers is outlined and an example of a successful tuberculosis control project is described. Nomadic populations are open to modern health care on the condition that this is not an instrument to control them but something they can control themselves.

Human papillomavirus infection, cervical dysplasia and invasive cervical cancer in Honduras: a case-control study

A substantial body of evidence has confirmed human papillomavirus (HPV) infection as the central etiological agent in human cervical carcinogenesis. In Honduras, cervical cancer is the most common cancer among women, with a high annual incidence. We conducted a population-based, case-control study of 229 patients with different grades of CIN and invasive cervical cancer and 438 matched controls. A structured questionnaire was used to investigate known and probable risk factors for cervical cancer. Cervical scrapes were tested for the presence of different HPV types using a general primer-mediated PCR followed by PCR-based sequencing. HPV DNA was detected in 87% of all cancer in situ and invasive cancer cases, and 95% of invasive cases could be attributed to high-risk types. In control women, 39% were positive for HPV DNA sequences. HPV 16 prevalence ranked highest in all stages of cervical dysplasias, invasive cancers and controls. A statistically significant association with HPV was observed for CIN II, CIN III and invasive cancer, showing an upward trend to more severe lesions and being more pronounced for HPV 16 and related types. The OR for HPV 16- and 18-related invasive cancer cases was 14.88 (95% CI 5.12-43.25) and 74.66 (95% CI 7.77-717.62), respectively. Our results confirm a central role of HPV as the cause of cervical cancer in Honduras and provide information as to the type distribution of HPVs in the country.

Alcohol consumption in the rural population of Misungwi subdistrict in Mwanza Region, Tanzania

OBJECTIVE

This study was undertaken to investigate the frequency and quantity of alcohol consumption in four villages on the southern shores of Lake Victoria, Tanzania.

METHOD

Study participants were 148 men and 162 women selected by cluster sampling from the population (N = 9,243) of four villages in Misungwi subdistrict, Mwanza Region, Tanzania. Interviews on self-reported alcohol consumption were conducted at the participants' home in Kiswahili using a standardized questionnaire.

RESULTS

Fifty-five percent of the men and 33% of the women had consumed alcohol at least once during the year prior to the interview; 24% of the men and 6% of the women had consumed alcohol on six or more occasions during the past month. The quantity of alcohol consumed at the last sitting and in the month prior to the interview was twice as high among male compared to female respondents. The frequency and quantity of alcohol consumption per month increased with age for men but not for women. The large majority of respondents consumed locally produced alcoholic beverages.

CONCLUSIONS

Alcohol consumption in this area was low compared to estimates from other parts of Tanzania and national data. Drinking patterns suggested that traditional rules and regulations concerning alcohol were still adhered to.

The National Leprosy Control Programme of Zimbabwe a data analysis, 1983-1992

Prevalence and detection rates of leprosy in Zimbabwe as well as patient characteristics were reported by the National Leprosy Control Programme over the 10-year period 1983-1992. The control programme made a new start in 1983 when multidrug therapy was introduced. Prevalence per 10,000 population declined steeply from 3.78 in 1983 to 0.52 in 1987. Prevalence continued to decline to 0.22 in 1992 and was highest in the north-eastern provinces. After an initial increase, the detection rate per 10,000 had declined from 0.19 in 1985 to 0.08 in 1992. The proportion of refugees among new cases had gradually increased since 1988 and amounted to one third in 1991 and 1992. An analysis of records of 802 cases who were newly detected from 1983 to 1992 showed that 51% were of the multibacillary (MB) type, 33% had visible disabilities at detection, 5% were under 15 years of age while the average delay time was 2.6 years. Patients with disabilities reported a longer delay time, were more often men and had more often the MB type of leprosy. The data suggest that transmission of leprosy is low but that cases are not diagnosed early enough to prevent transmission altogether.

A sero-epidemiological study of the relationship between sexually transmitted agents and cervical cancer in Honduras

To investigate a possible cause-and-effect relationship between sexually transmitted diseases and cervical cancer, we performed a sero-epidemiological study on the presence of antibodies against a number of sexually transmitted agents (STAs) in patients with cervical cancer and their matched controls. In this study, we used serological techniques to investigate the presence of antibodies to cytomegalovirus, herpes simplex virus type 2, human immunodeficiency virus, Chlamydia trachomatis, Treponema pallidum and human papillomavirus (HPV) early protein E7 in sera from patients with cervical cancer, cervical intra-epithelial neoplasia and individually matched, healthy controls. The presence of antibodies to infectious agents other than HPV appeared not to be associated with risk of cervical neoplasia in either univariate or multivariate analysis. After adjustment for cytology, schooling and presence of HPV DNA in cervical scrapes, there was a significantly higher prevalence of antibodies to HPV-16 E7 protein in sera from patients with cervical cancer (OR = 3.6, 95% CI 1.0-12.9) than in healthy controls. The highest antibody prevalence was found among HPV-16 DNA-positive cervical cancer patients (33%). Our results indicate that in these study groups past infections with the STA considered seems to be of no apparent relevance for cervical carcinogenesis and that the HPV-16 anti-E7 response appears to be associated with cervical cancer.

Typhoid fever in Ujung Pandang, Indonesia--high-risk groups and high-risk behaviours

We performed a hospital-based case-control study to identify high risk groups and routes of transmission of typhoid fever in the city of Ujung Pandang on the island of Sulawesi, Indonesia. The annual incidence of this disease in southern Sulawesi is estimated at 3.1/1000 and the case fatality at 5.1% Cases were 50 patients over 13 years of age admitted to Stella Maris Hospital with a diagnosis of typhoid fever between June and September 1991. Diagnosis was made on clinical grounds and in 90% of cases confirmed by a Widal test. Controls were 42 patients admitted for non-infectious disorders during the same period and individually matched by age and sex. Controls did not have a history of typhoid fever. Interviews took place in hospital. Analysis was by unconditional logistic regression. High-risk groups consisted of those who were single, unemployed and those who had a university education. Median age of cases was 22 years. Consumption of food from warungs (food stalls in the street) was strongly associated with risk (OR = 45). Both cases and controls washed hands after use of the toilet and before meals, but cases used soap significantly less often (OR = 30). The results of this study can be used to take preventive measures against this severe disease of educated and single young adults by targetting them for IEC-activities emphasizing the importance of thorough hand-washing and the need to take care in the selection of street-foods.

Association of infections with human immunodeficiency virus and human papillomavirus in Honduras

The etiologic role of the oncogenic types of human papillomavirus (HPV) in the development of cervical cancer has been widely proven. Since this cancer occurs more frequently in immunosuppressed individuals, we sought to evaluate the prevalence of HPV infection among human immunodeficiency virus (HIV)-infected and HIV-noninfected prostitutes in Tegucigalpa, Honduras. Cervical scrapes were collected from 23 HIV-seropositive and 28 HIV-seronegative prostitutes for HPV DNA detection by the polymerase chain reaction. Fifty-six percent of the HIV-seropositive women and only 18% of the seronegative women were HPV DNA positive (odds ratio = 6.0). In addition, there was a significant association between seropositivity for HIV with a history of sexually transmitted diseases (P < 0.01). Our data confirm the association between infections with HIV and HPV.

HIV-1 incidence and HIV-1 associated mortality in a cohort of urban factory workers in Tanzania

OBJECTIVE

To determine HIV-1 incidence and HIV-1 associated mortality in a prospective cohort study. To determine whether the cohort is suitable for studies aiming to determine the impact of interventions on HIV-1 incidence.

METHODS

The study population was a cohort of 1772 urban factory workers (1478 men and 294 women) in northwest Tanzania. The study took place from October 1991 to September 1993. Outcome measures were HIV-1 seroconversion and death.

RESULTS

HIV-1 incidence was 1.2 (95% CI 0.7-2.0) per 100 person-years (pyr). Crude annual mortality was 4.9 per 100 pyr in those with and 0.3 in those without HIV-1 infection, giving an age and sex adjusted mortality ratio of 12.9 (95% CI 5.4-30.7). Of all deaths, 62% were attributable to HIV-1 infection.

CONCLUSION

HIV-1 infection was a major public health problem, being the major cause of death in this adult population. At an HIV-1 incidence of 1.2 per 100 pyr, a large cohort size would be required to evaluate the impact of interventions on HIV-1 incidence.

Sexual partner change and condom use among urban factory workers in northwest Tanzania

OBJECTIVE

To describe sexual partner change and condom use at the intake of a cohort study of urban factory workers in Tanzania.

METHODS

From October 1991 to March 1992, 926 male and 170 female factory workers were interviewed using a structured, pre-coded questionnaire. Questionnaire reliability was assessed by pre-testing and comparison with results of unstructured interviews and carrying out repeat questionnaires on a sub-sample.

RESULTS

Almost half of both men and women had had sexual intercourse by their 17th birthday. The period of premarital sex had an interquartile range of 2 to 10 years in men and 0 to 2.5 years in women. Having had sexual intercourse in the past month with more than one partner was reported by 22% of the men and 5% of the women. Factors associated with multiple partners in men were being born in or near Mwanza Region, having low education and low income, and being married. Condoms had been used in the past month by 3% only, mainly with casual partners. Condom use in men was associated with being young, living in town, being born in Kagera Region, high education and high income, being circumcised, and having causal or steady (non- martial) partners.

CONCLUSION

Information, education and communication (IEC) on sexual relationships and condom use should start at an early age, and include education at primary schools. Much sexual partner change appears to occur through steady (non-marital) partnerships, indicating the need for IEC to be expanded beyond groups such as commercial sex workers and their clients.

Estimating gallstone incidence from prevalence data

Because incidence data for gallstones are generally unavailable, we have used a previously described epidemiologic method to estimate age-specific incidence rates from published gallstone prevalence data in seven populations. Yearly incidence rates ranged from a low of 1 in 1000 for the younger men to 19 in 1000 for the oldest women. An overall pattern of increasing incidence of disease with increasing age was observed. Rate-ratios for oldest versus youngest subjects ranged from 4.0 in German women to 9.4 in Italian men: mean rate-ratio = 5.9; 95% CI = 4.0-7.8. For all centers, age-specific female incidence rates exceeded comparable age-specific male rates at all ages (mean female to male rate-ratio = 1.85; 95% CI = 1.7-2.0). No differences were observed in the sex-specific incidence of gallstones for subjects of similar age in the various centers (P = > 0.10). For Denmark our estimates resemble recently published incidence data obtained by re-surveying the original population.

Malaria morbidity and mortality in children under three years of age on the coast of Benin, West Africa

Malaria morbidity and mortality were measured in a population of 1500 children under 3 years of age from April to December 1989. During monthly home visits, an average of 26 children in 1000 had fever, of whom 15 had parasitaemia. Children less than 6 months old had significantly fewer fever episodes, whether associated with parasitaemia or not. Overall, prevalence of fever with parasitaemia rose steadily from April to August, then decreased but reached a second peak in November. Peaks coincided with the 2 rainy seasons in April to June and September to October. Comparison with a control group demonstrated that children with parasitaemia exceeding 1000 infected red blood cells per microliter of blood had fever significantly more often than children with lower levels of parasitaemia. The average number of fever episodes per child per year was 2.4, and 33% of these were estimated to be caused by malaria. All cause mortality was 26/1000/year and the malaria mortality rate was 8/1000/year. Malaria deaths were most frequent in the second year of life.

Childhood mortality among users and non-users of primary health care in a rural west African community

To evaluate the effectiveness of primary health care (PHC) interventions implemented through the Pahou PHC Project, the utilization of PHC by 74 children aged 4 to 35 months who died in 1986 or 1987 was compared to that of 230 controls who survived and were individually matched by date of birth, sex and place of residence. The crude death rate was 35.9/1000/year. Measles vaccination before the first birthday significantly reduced the risk of mortality (Relative Risk/RR = 0.4). Children with less than 75% weight for age early in 1986 had an increased risk (RR = 4.3). Children who died had had significantly fewer contacts with the village health worker (VHW) in the last six months prior to death (RR = 0.3). A similar association was not observed for periods more than six months prior to death. Children who had more regular contact with the VHW throughout life were better protected than children for whom contact had been less systematic. We conclude that VHWs contribute to a better survival of young children through regular personal contact with the household.

The evaluation of agreement by means of log-linear models: proxy interviews on reproductive history among floriculture workers in Colombia

We used data from Colombia to compare responses from husbands and wives concerning the reproductive history of the women. We analyzed agreement in two ways: First, we compared kappa statistics between independent subgroups. Second, we evaluated agreement by means of log-linear models. Men underreported the total number of pregnancies and the number of abortions of their wives. Agreement on the term of the pregnancy was dependent on the ages of the partners. Log-linear modeling provides an attractive alternative to more usual ways of studying agreement.

Age curves of central nervous system tumor incidence in adults: variation of shape by histologic type

Data from nine population-based cancer registries from the National Cancer Institute's Surveillance, Epidemiology, and End Results program of the United States were used to study the incidence of individual histologic types of malignant central nervous system tumors by age and sex among adults. On a log-log scale, incidence increased linearly between the ages 35 and 64, with a slope that was not different between males and females or among registries but that varied by histologic type. The estimated slopes were 0.4 for ependymomas, 1.0 for oligodendrogliomas, 1.7 for astrocytomas, 2.8 for meningiomas, and 3.9 for glioblastomas. The rate at which incidence increased with age was significantly higher for glioblastomas than for other glial tumors. This finding suggests a different mechanism of carcinogenesis for glioblastomas than for other glial tumors.

The age curve of nervous system tumour incidence in adults: common shape but changing levels by sex, race and geographical location

A multiplicative model was fitted to incidence rates of nervous system tumours cross-tabulated for each sex by five-year age groups between ages 35-64 and 51 populations in which at least ten cases had been observed and 60% of cases histologically verified. There was no significant departure from a model in which the age curve was assumed to have the same shape but a different level in each population. On log-log scale this shape was a straight line with identical slope (2.6) for males and females. Population-specific multipliers were highest in Israel and lowest in Asia. Within the US, rates were significantly lower among blacks, Hispanics, Chinese and Japanese compared to whites. A model for both sexes combined showed that sex ratios were rarely below unity but varied significantly between populations. Exposure (or susceptibility) to as yet unidentified aetiological factors appears to be higher in males and whites than in females and non-whites.

Can cardiac death be predicted from an ambulatory 24-hour ECG?

For the prediction of cardiac death significant prognostic information can be derived from ambulatory 24-hr ECGs when they are recorded on indication in the cardiological outpatient-clinic. In both CHD and non-CHD patients, ventricular arrhythmias, supraventricular arrhythmias and conduction disturbances are all of importance in the assessment of prognosis. These conclusions are based on a review of all 123 cardiac deaths and 433 randomly selected survivors from a cohort of 5095 patients who underwent 24-hr ECG-recording on clinical indication and whose survival status was ascertained 18 months after the recording date.

The effect of a natural high-fiber diet on serum lipids, fecal lipids, and colonic function

In a cross-over experiment, 46 young healthy volunteers consumed in succession a high-fiber and a low-fiber diet for 3 weeks at two levels of dietary cholesterol. Half of the dietary fiber came from fruits and vegetables, and the rest from bread and other cereal products. On the high-fiber diet, concentrations of serum cholesterol decreased on average by 0.44 mmole/liter with high-cholesterol and 0.31 mmole/liter with low-cholesterol regimes; high density lipoprotein-cholesterole decreased by 0.1 mmole/liter; on average fecal weight increased by 115 g/day and mean transit time through the gut was decreased by 18 hr. Only part of the decrease in serum cholesterole may be due directly to the high intake of dietary fiber components. The remainder is due to differences in fat intake: during the high-fiber period subjects consumed less fat and cholesterol than had been planned.