Disease Control Priorities in Developing Countries. During that time, the epidemiology of STIs has changed in developing countries, partly as a result of modifications in STI case management approaches and partly because of behavioral changes in response to the HIV epidemic.
At the same time, advances in STI prevention have enhanced understanding of the intricacies of STI transmission dynamics and the role of interventions in the control of STIs.
However, what has not changed is as significant as what has changed: The sociocultural and economic contexts in developing countries influence the epidemiology of STIs and help make them an important public health priority.
Incidence and prevalence rates of STIs are generally high in both urban and rural populations and vary considerably across areas.
Because diagnosis and treatment of STIs are often delayed, inadequate, or both, rates of STI complications are also high in developing countries. Those complications include "Sexually transmitted diseases journal editorial manager university" inflammatory disease, ectopic pregnancy, and chronic abdominal pain in women; adverse pregnancy outcomes, including abortion, intrauterine death, and premature delivery; neonatal and infant infections and blindness in infants; infertility in both men and women; urethral strictures in men; genital malignancies, such as cancer of the cervix uteri, vulva, vagina, penis, and anus; arthritis secondary to gonorrhea and chlamydia; liver failure and liver cancer secondary to hepatitis B or human T cell lymphotropic virus type I; and central nervous system disease secondary to syphilis Holmes and Aral ; Meheus, Schulz, and Cates ; van Dam, Dallabetta, and Piot Thus, STI sequelae affect mostly women and children.
In developing countries, high levels of STIs and high rates of complications and sequelae result largely from inadequacies in health service provision and health care seeking Aral and Wasserheit STI care is provided by a large variety of health care providers, many of whom are poorly trained in STI case management, and the quality of care they provide is often less than desirable Moses and others ; WHO Health care seeking for STIs is frequently inadequate, particularly among women van Dambecause of the low levels of awareness regarding sexual health, the stigmatization associated with genital symptoms, and the asymptomatic nature of many STIs.
A study in Nairobi, Kenya, found that 42 percent of patients had been symptomatic for more than a week before coming to a clinic and that 23 percent had been symptomatic for more than two weeks Moses and others Setting up good-quality STI services is considerably more difficult in resource-poor settings than elsewhere.
Variables that affect the duration of infectiousness include adequacy of health workers' training, attitudes of health workers toward such marginalized groups as sex workers, patient loads at health centers, availability of drugs and clinic supplies, and costs of care Moses and others Sexually transmitted diseases journal editorial manager university, improvements pertaining to all these factors would greatly improve STI-related services, help reduce the duration of infectiousness, Sexually transmitted diseases journal editorial manager university decrease the incidence of STIs Aral a.
For example, in South Africa, the ratio of hospital beds to population declined from 6. Sexual behaviors also contribute to the STI burden in developing countries.
These behaviors are heavily influenced by the sociocultural, economic, and political contexts, which in the past two decades have deteriorated at an accelerated rate in many areas.
Societal change has included rising levels of inequality within countries, growing inequality between countries, increased levels of globalization, increased proportions of people who live in cultures they were not born in, and a larger proportion of the world's population living in postconflict societies Aral a. One effect of these changes is increase in multipartner sexual activity, which in turn increases the rate at which infected and susceptible individuals are sexually exposed to each other and consequently the rate at which STIs spread.
SinceSTI epidemiology and management have evolved interactively, particularly in developing countries. Technological advances in diagnosis, screening, and treatment; evaluation and widespread implementation of new case-management algorithms; and changes in risk behaviors in response to the AIDS epidemic have all influenced the dynamic typology of STIs Wasserheit and Aral The introduction of nucleic acid amplification tests, which have improved the sensitivity and expanded the repertoire of usable Sexually transmitted diseases journal editorial manager university, has heralded a new era in STI diagnosis.
The use of urine and vaginal swabs in diagnosis has enabled providers to supply diagnostic and screening services outside traditional clinical facilities and has greatly enhanced the coverage of outreach activities Schachter Unfortunately, many of these tests are currently too expensive for routine use in developing countries. Single-dose oral azithromycin has improved the treatment of several bacterial STIs Lau and Qureshibut quinolones are apparently becoming ineffective for gonorrhea in some locations Donovan A major recent advance in STI prevention is the early success of a prophylactic, monovalent human papillomavirus HPV type 16 vaccine Koutsky and others ; HPV vaccines may be able to help prevent genital and anal cancers in the foreseeable future.
Researchers are evaluating multivalent vaccines for preventing moderate to severe cervical dysplasia as well. Other advances include easier episodic treatment of genital herpes Strand and others and the use of suppressive therapy to reduce the transmission of genital herpes to regular partners Corey and others In a related development, a prophylactic vaccine against herpes simplex virus type 2 HSV-2 has shown limited efficacy in that it has proved partly effective for HSV-seronegative women, but not for men or herpes simplex virus type 1 HSV-1 seropositive women Stanberry and others Prevention successes of the recent past include STI sequelae, such as pelvic inflammatory disease and cervical cancer.
A randomized controlled trial showed that selective screening of women for Chlamydia trachomatis significantly reduced the incidence of pelvic inflammatory disease Scholes and others Widespread implementation of syndromic management as an approach to STI case management has apparently had a considerable effect on the epidemiology of STIs, particularly in resource-poor settings King Holmes and Michael Alary, personal communication, May 15, In some developing countries, including Cambodia, the Dominican Republic, and Thailand, sexual risk behaviors have been changing over the past decade.
In Uganda, for example, the age of sexual debut has increased, the frequency of sex with casual partners has decreased, and the use of condoms has increased Stoneburner and Low-Beer During the s, demographic and health surveys in 29 developing countries asked individuals if they had done anything to avoid AIDS Low-Beer and Stoneburner Specific behavior changes reported included increased monogamy, reduced number of partners, avoidance of sex workers, and increased condom use.
By contrast, in developed countries, recent years have seen behavior changes in the opposite direction; for example, in many European countries and in the United States, risk behaviors among men who have sex with men have increased significantly CDC ; L. Doherty and others Investigators attribute increases in risk behaviors to the introduction and availability of antiretroviral therapy for HIV Sexually transmitted diseases journal editorial manager university and the difficulties in sustaining preventive behaviors in the long term, referred to as prevention fatigue.
Some researchers speculate that the widespread introduction of antiretroviral therapy in developing countries may have a similar disinhibitory effect on sexual behaviors and that changes in sexual behavior may offset the beneficial effect of antiretroviral therapy Blower and others ; Blower and Farmer ; Blower and Volberding ; Over and others Advances in STI prevention in recent decades have enhanced understanding of transmission dynamics and the role of interventions.
Investigators have articulated the following five emergent insights about STI epidemiology and prevention over the past two decades:.
The epidemiology of STI pathogens, the local prevention and care infrastructure, and the cultural and sociopolitical context vary considerably within and across developing countries. At the same time, health care delivery for STIs varies by type of institution and location, although inadequate resources are universal in the developing world, as are recordkeeping, data management, and data analysis.
The limited data that are available suggest that STIs are a major public health burden in the developing world. Although the prevalence and incidence of bacterial STIs have apparently declined because of expanded syndromic management, changes in sexual behavior, and death of high-risk populations, the prevalence and incidence of viral STIs seem to have increased over the past decade.
Health systems can use three different approaches to manage patients presenting with symptoms suggestive of an STI.