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.

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.

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.

PIP: Numerous studies have revealed a higher prevalence of human papillomavirus (HPV)--etiologically linked to the development of cervical cancer--in women infected with HIV. This study investigated the association of HPV and HIV among 51 prostitutes in Tegucigalpa, Honduras. 23 were HIV-positive. All participants were in their early thirties, had had at least one pregnancy, and experienced their first pregnancy at a mean age of 16 years. Polymerase chain reaction identified HPV DNA in cervical scrapes from 13 (56.5%) HIV-positive women compared with only 5 (18%) HIV-negative prostitutes (odds ratio, 6.0; 95% confidence interval, 1.5-26.7). In addition, there was a significant association between HIV and a history of other sexually transmitted diseases (p 0.01). Since the progression to invasive cervical disease is more aggressive in HIV-infected women, prostitutes and other women at risk of both these infections should receive frequent cytologic screening and counseling.

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.