Syphilis in China

Introduction

Syphilis was first documented in China in 1505. By the 1940’s, Syphilis had become a major epidemic within China. As the communist party took over China in 1949, the political party made the disease a priority and launched a campaign in 1952 to abolish the disease [1]. Before the party launched its campaign, it was estimated that 5% of the population in large cities carried the disease. The campaign consisted of wide screening, free treatment, and a crack down on prostitution – a major factor for the spread of the disease [2]. By 1964, Syphilis had become a rarity and infection nearly eliminated, until its international borders were opened in the 1980’s [1].

A natural development of immunity towards Syphilis is possible. However, due to the fact that China had been “cleaned” of Syphilis for about 20 years after the campaign, the young sexually active generation lacked the natural immunity. This resulted in detrimental effects to China when unprotected sexual contact was made with foreigners that had the disease [1]. The disease spread over time, as sex education was practically nonexistent and public awareness of the disease dwindled. The result was a heavy resurgence of Syphilis in the late 1990’s and early 2000’s. Recent data has shown that the rate of syphilis has jumped from 0.2 cases per 100,000 people in 1993 to 5.7 per 100,000 in 2005. In even larger cities, such as Shanghai, the rate is estimated to be as high as 55 cases per 100,000 people [2]. Congenital syphilis cases, in which the disease is passed on through the mother to a newborn, are estimated to be about 3,400 a year [2].

Description of Syphilis

Syphilis is a spirochetal bacterium known as Treponema Pallidum. “The spiral-shaped body of T. pallidum is surrounded by a cytoplasmic membrane, which is enclosed by a loosely associated outer membrane. A thin layer of peptidoglycan between the membranes provides structural stability.” T. Pallidum contains spirochetes that have an endoflagella which allows the bacteria to move in a corkscrew formation through the viscous fluid of the periplamic space; thus T. Pallidum is a Gram Negative Bacterium.

What is interesting to note is that T. Pallidum cannot live independently. It can only survive inside host cells of mammals, thus T. Pallidum is an endosymbiont. Once it penetrates into the host cell, “T. pallidum derives most essential macromolecules from the host, using interconversion pathways to generate others.”

T. Pallidum has a slow growing rate relative to other bacteria. One reason is due to the fact that T. Pallidum does not contain a tricarboxylic acid cycle and an electron transport chain. So it depends only on glycolysis, which makes 2 ATP molecules per glucose. Therefore the low energy source slows the growth rate significantly. Moreover, “because of a lack of enzymes such as catalase and oxidase that detoxify reactive oxygen species, the in vitro survival of T. pallidum is prolonged by low oxygen concentration.”

Finally, motility of the T. Pallidum depends upon adhesions and the process of chemotaxis. The bacteria use its pili as an adhesion to attach to host cells, and they use treponems in the adhesion process. Moreover, T. Pallidum uses methyl accepting chemotaxis transmembrane proteins (MCPs) that “sense attractants and repellents in the environment; glucose and histidine are molecules that may have affinity for T. pallidum MCPs. Pathogenic processes such as crossing the endothelial barrier to reach the bloodstream are likely to depend upon mechanisms that allow T. pallidum to sense and respond to nutrient gradients.”

Syphilis’s microbe, Treponema Pallidum, has very strong motility to swim through gel-like fluids; but it is a sensitive bacterium that is very dependent on its host cell to survive. If this Gram Negative Bacterium is removed from the mammalian cell it will die within hours because of the lack of nutrients that the host cell can provide.

Transmission of disease

How is it transmitted? Is there a vector (animal/insect)?

Why is this disease a problem in China

Since China defeated syphilis in the 1950’s it has returned strong due to a variety of reasons. Since Mao Ze Dong’s rule China has evolved socially, economically, and politcally. Biologically speaking, complete eradiction of the disease in earlier decades has reduced the amount of immunity for sexually active adults now (who were children at the time) [X]. This is because syphilis infection causes an immune response which reduces the possibility of re-infection in the future [Z]; if they were not exposed to it at all their body has built no defense toward it.

The attitudes towards sex have also changed in which there is an increase in amount of sexual partners, extramarital relationships, and prostitution [Z]. The less conservative view on sex coupled with lack of protection has contributed to the wider spread of the disease in the country. While the attitudes towards sex have changed, open communication about sexual relations hasn’t, making it difficult for patients possibly infected to be treated accordingly. Along with lack of communication to health care providers, lack of communication between sexual partners hampers spread from stopping [X].

Homosexuality once considered unacceptable in all realms is gaining momentum towards complete acceptability. In urban areas gay clubs/bars have opened and annual parades celebrate their lifestyle and culture. Studies show that the highest rates for syphilis in urban areas from China are from men having sex with men (MSM) [Z].

Also feeding towards the spread is population mobility which was not feasible during Mae Ze Dong’s rule. Beginning in the late 1980’s the Chinese government started lifting travel restrictions allowing rural populations to move to cities to find work [Z]. The number of rural-urban migrants went from 50 million in 1990 to 120 million in 2000, with estimates around 160 million by 2010 [Z]. Although not supported by studies, it is assumed that migrants are feeding the demand for the sex industry which leads to the spread of STD’s. Furthermore, business men moving into China are feeding the sex industry - a study among sex workers in brotherls in Yunnan Province shows that almost all of the clients were foreign business men [Z].

Lastly, a major player in the syphilis epidemic is the collapse of the universal free health care (and public health in general) in the 1970’s [Z]. Currently, much of the healthcare is privatised with patients paying out of pocket. This is an issue because people possibly infected are not seeking health treatment due to lack of funds. This was demonstrated in a study done in an area outside of Beijing where 80% of women with genitourinary symptoms did not seek health care partially due to cost (in other park lack of understanding toward the severity of the problem) [Z].

On a global note, syphilis has relations to the rate of HIV spread. The presence of syphilis enhances the viral load in infected people, while also enhancing transmission of HIV [Z].

Overall: The symptons of syphilis can be wide ranging, often bieing confused with other conditions, and may also be asymptomatic, making diagnosis a particular challenge (Hesketh).

The rising rates of syphilis in China are largely attributed to factors regarding socioeconomic, educational and lifestyle issues. The current clinical guidelines for syphilis detection are based on symptomatic criteria, overlooking opportunities to assess risk factors to further improve disease control. This method does not include blood tests, such as the toluidine red unheated serum test (TRUST) and Treponema pallidum particle agglutination test (TPPA), which can detect syphilis even if an individual does not show any hallmark symptoms of the disease [A].

In Guangxi, China, a study investigating the effectiveness of a potential screening tool revealed that 40.9% of patients that tested seropositive did not show the hallmark signs of syphilis[A]. The study indicates that the current testing guidelines for syphilis are not efficient in detecting positive cases in which symptomatic signs are not visible [A]. These shortcomings are problematic due to their low efficacy rates in disease detection.

The current testing guidelines also lack behavioral risk assessment as a factor in detecting sexually transmitted diseases. In the aforementioned survey, women were less likely to disclose risk behaviors due to fear of stigma associated with sexual behaviors [A]. The shame associated with revealing such behaviors lowers the chance of discovering risk behaviors that would indicate the presence of a sexually transmitted disease.

Congenital syphilis is another major problem among pregnant women in China. In one particular area, Shenzhen, China, syphilis cases began to reappear in 1983, after having been nearly extinguished in the 1960’s. From 1996 to 2001, the number of congenital syphilis cases had risen from one to 36 reported cases. In a study in Shenzhen that screened and treated pregnant women for congenital syphilis, most of the infected pregnant women fit into specific demographics. The majority were young, had poor educational backgrounds, tended to migrate frequently, and usually worked in the commercial or service industries or were unemployed. Their lack of knowledge of STD’s, in addition to their lack of communication with the healthcare system placed these women at high risk for congenital syphilis. In the study, 63% of mothers who had transmitted congenital syphilis had never had prenatal examinations before childbirth. Also, the fact that many of these women migrated so often lowered the chances that women would return to clinics for follow-ups, a major factor in preventing congenital syphilis and the transmission of the disease from mother to child. [B]

What is being done to address this problem

Dr. Mryon S. Cohen, who has worked in China since 1979, worked in collaboration with Dr. Xiang-Sheng Chen from the National Center for STD Control in Nanjing to compile a report on the Syphilis resurgence. The complied report provides data to let the government know where to allocate their resources. As a result, a “China Syphilis Working Group” has formed, working with the UNC, China's National Center for STD Control, the World Health Organization, the United Nations Center for Disease Control and the London School of Hygiene [1].

In July 2002, a three-year program was introduced to 61 hospitals in Shenzhen that focused on the free screening and treatment of pregnant women for syphilis. The Shenzhen Center for Disease Control and Prevention (SZCDC), conducted primary screenings using toluidine red unheated serum test (TRUST), then retested the positive results using the Treponema pallidum particle agglutination (TPPA) test. Women that tested positive were treated, and their babies were tested for congenital syphilis using the 19S-IgM FTA-Abs test. [B]

The program managed the positive cases in accordance with China’s Diagnostic Criteria and Management of Syphilis guidelines as well as the US Center for Disease Control Guidelines for the Prevention and Control of Congenital Syphilis. The women that decided to terminate their pregnancies were treated with penicillin or azithromycin. Women that continued with their pregnancies were treated with benzathine benzylpenicillin or erythromycin. [B]

Of the women who received intervention treatment for the prevention of mother-to-child transmission of the disease, 99.1% of potential cases were successfully prevented. By the time the program had finished, the average incidence rate of congenital syphilis cases was less than half that when the program started. The program relied partially on the political and financial support from the local government, which funded the free screening, treatment and follow-ups. The screening instruments and treatment medicines were effective and inexpensive. [B]

What else could be done to address this problem

In 1949, China experienced one of the worst syphilis epidemics, estimating that 5% of the population is large cities carried the disease. As the Communist party took power, free treatment and screening was offered for the disease. The Communist party cracked down on prostitution as well, which results in a near elimination of syphilis [2]. Ironically, due to the near elimination of Syphilis by the Communist party in the 1960’s, the unexposed Chinese population lacks this natural immunity, making them more susceptible to the disease [2] as their borders were opened internationally in the 1980's.

One important factor that contributes to recent outbreaks is the fact that more people are more people are moving to larger cities for work, resulting in an increase in demand for prostitutes with low use of protection [2]. Another is the lack of use of protection among homosexual males [3]. Premarital sex has become more acceptable within Chinese culture, resulting in larger outbreaks. There are also less adult screening programs for syphilis [2].

Treating the disease in China is not a scientific problem, but a socio-political problem. China remains one of the most conservative countries in the world. As a result, topics of sexual intercourse are generally taboo, as well as sexually transmitted diseases [3]. To combat the vast increase within the past decade, China should reform it's educational system to include sex education. They should also publicly promote the use of protection. An entire reform from it's conservative culture is essentially required to best to address the problem. In addition, new adult screening programs should be established and antibiotics should be made easily available by the government to deal with the current syphilis outbreaks [2], as it did in 1949.

References

[1]. University of North Carolina School of Medicine. "Resurgence And Spread Of Syphilis In China Is A Rapidly Increasing Epidemic". ScienceDaily. 12 January 2007. 25 August 2009 <http://www.sciencedaily.com/releases/2007/01/070112104258.htm>.

[2]. Roxanne Khamsi. “Syphilis rates skyrocket in China”. New Scientist. 12 January 2007. 25 August 2009 <http://www.newscientist.com/article/dn10940>.

[3]. Iamseven. “Syphillis on the rise in China”. Digital Journal. Jan 11, 2007. 25 August 2009 <http://www.digitaljournal.com/article/90014>

[A].

[B].

[4]. LaFond, Rebecca E., Lukehart, Sheila A. "Biological Basis for Syphilis". Clinical Microbiology Reviews. 2006. Volume 19. p.29-49. <http://cmr.asm.org/cgi/content/full/19/1/29>

Edited by [insert your names here!], students of Rachel Larsen